Hydrogel microspheres for bone regeneration through regulation of the regenerative microenvironment

doi:10.12336/biomatertransl.2024.03.002

Biomaterials Translational ›› 2024, Vol. 5 ›› Issue (3): 205-235.doi: 10.12336/biomatertransl.2024.03.002

• REVIEW • Previous Articles Next Articles

Hydrogel microspheres for bone regeneration through regulation of the regenerative microenvironment

Pengrui Zhang¹, Qiwei Qin¹, Xinna Cao¹, Honglin Xiang¹, Dechao Feng², Dilinaer Wusiman³, Yuling Li¹^,^*()

1 Department of Orthopaedics, Laboratory of Biological Tissue Engineering and Digital Medicine, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan Province, China
2 Division of Surgery & Interventional Science, University College London, London, UK
3 Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA

Received:2024-06-27 Revised:2024-08-12 Accepted:2024-09-13 Online:2024-09-28 Published:2024-09-28
Contact: Yuling Li, lyl1987@nsmc.edu.cn.

Recommend

Abstract

Abstract:

Bone defects are a prevalent category of skeletal tissue disorders in clinical practice, with a range of pathogenic factors and frequently suboptimal clinical treatment effects. In bone regeneration of bone defects, the bone regeneration microenvironment—composed of physiological, chemical, and physical components—is the core element that dynamically coordinates to promote bone regeneration. In recent years, medical biomaterials with bioactivity and functional tunability have been widely researched upon and applied in the fields of tissue replacement/regeneration, and remodelling of organ structure and function. The biomaterial treatment system based on the comprehensive regulation strategy of bone regeneration microenvironment is expected to solve the clinical problem of bone defect. Hydrogel microspheres (HMS) possess a highly specific surface area and porosity, an easily adjustable physical structure, and high encapsulation efficiency for drugs and stem cells. They can serve as highly efficient carriers for bioactive factors, gene agents, and stem cells, showing potential advantages in the comprehensive regulation of bone regeneration microenvironment to enhance bone regeneration. This review aims to clarify the components of the bone regeneration microenvironment, the application of HMS in bone regeneration, and the associated mechanisms. It also discusses various preparation materials and methods of HMS and their applications in bone tissue engineering. Furthermore, it elaborates on the relevant mechanisms by which HMS regulates the physiological, chemical, and physical microenvironment in bone regeneration to achieve bone regeneration. Finally, we discuss the future prospects of the HMS system application for comprehensive regulation of bone regeneration microenvironment, to provide novel perspectives for the research and application of HMS in the bone tissue engineering field.

Key words: bone regeneration, bone tissue engineering, hydrogel microspheres, regeneration microenvironment

Cite this article

Figures/Tables 11

Figure 1. Schematic diagram of the bone regeneration microenvironment. (A) Physiological, chemical, and physical factors in the bone regeneration microenvironment; (B) Brief schematic diagram of the osteogenic process in the bone regeneration microenvironment. (B1) Physiological microenvironment in which neurons, endothelial cells, macrophages, and osteoblasts differentiate into neural tissue, vascular tissue, M1/M2 cells, and bone tissue. (B2) Chemical microenvironment in which cytokines such as NGF, BMP-2, and VEGF promote differentiation of neuronal cells, osteoblasts, and endothelial cells to jointly promote bone regeneration; pH and ROS of the microenvironments in pathological and physiological conditions. (B3) Physical microenvironments in which physical stimuli such as ultrasound, infrared light, mechanical force, electrical stimulation, and magnetism promote the migration, proliferation, and differentiation of MSCs into bone. (B4) Stimuli such as electrical stimulation, magnetic and mechanical forces, near-infrared light, and ultrasound promote osteogenesis expressed by osteocytes. Created with BioRender.com. ALP: alkaline phosphatase; AMPK: adenosine monophosphate-activated protein kinase; ATP: adenosine triphosphate; BMP-2: bone morphogenetic protein-2; CALM: calmodulin; Col1: collagen I; CRY: cryptochrome; MSC: mesenchymal stem cell; NGF: nerve growth factor; NIR: near infrared; OCN: osteocalcin; Osx: osterix; pH: potential of hydrogen; ROS: reactive oxygen species; Runx2: Runt-related transcription factor 2; Smad1: small mother against decapentaplegic homolog 1; VEGF: vascular endothelial growth factor.

Table 1. Hydrogel microsphere preparation materials and their advantages and disadvantages

Raw material	Preparation method	Advantage	Disadvantage
Natural polymer hydrogel microsphere
Collagen⁶²	Emulsification	1. Cell adhesion and growth; 2. Bioactivity	1. low mechanical strength; 2. Immunogenicity risk; 3. Rapid degradation rate
Gelatin^{71, 72}	Emulsification; Microfluidics; Electrospray	1.Good biocompatibility; 2. Easy processing and low cost; 3. Functionalization and cross-linking	1. Low mechanical strength; 2. Rapid degradation rate and degradation byproducts
Chitosan⁷⁴	Emulsification; Electrospray	1. Safe degradation byproducts; 2. Antimicrobial properties	1. Allergy risk; 2. Low cellular interactions; 3. Low degradation rate
Silk fibroin^64⇓-66	Microfluidic; Electrospray	1. Cell Adhesion; 2. Good mechanical strength	1. Hydrophobicity; 2. Slower degradation rate
Chondroitin sulfate⁷⁵	Emulsified	1. Anti-inflammatory, antioxidant, regulates enzyme activity, cellular activity, and communication; 2. Negative electronegativity	1. Rapid degradation; 2. Limited mechanical strength
Fibrous protein^64⇓-66	Emulsified; Electrospray	1. Mimics natural extracellular matrixc; 2. Facilitates vascular regeneration and cytokine adhesion	1. The preparation process is complex and costly; 2. Potential for infection
Chitin⁸⁵	Emulsified	1. Good biocompatibility; 2. good biosorption properties	1. High production costs; 2. Lower mechanical properties
Synthetic hydrogel microsphere
Alginate⁸⁶	Emulsified; Microfluidic; Electrospray	1. Good biocompatibility; 2. Easy to cross-link; 3. Ease of Gelation	1. Low degradation rate; 2. Sensitivity to pH
Polylactic acid-hydroxybutyric acid copolymer⁷¹	Emulsification; Electrospray	1. High tunability; 2. Acceptable mechanical strength	1. Structural Instability; 2. Acid product
Gelatin methacrylate⁸⁷	Emulsification; Microfluidics; Electrospray	1. Adjustable mechanical properties; 2. Adjustable physicochemical properties	1. Limited mechanical behavior; 2. Complex preparation
Polycaprolactone⁸⁸	Microfluidic; Electrospray	1. Acceptable biocompatibility; 2. High mechanical strength	1. Acidic products; 2. Slow degradation rate
Cellulose compound⁸⁹	Emulsified	1. Good biocompatibility; 2. High mechanical strength and stable chemical structure	Poor flexibility and water solubility
Polyethylene glycol⁹⁰	Emulsified; Microfluidics	1.High hydrophilicity, low immunogenicity, highly biocompatible, biodegradable; 2. Easy to modify and functionalize	1. Poor biological activity; 2. Limited mechanical strength
Polyvinyl alcohol⁹¹	Emulsified; Microfluidics; Electrospray	1. High water solubility, high biocompatibility; 2. Easy to modify and functionalize.	1. Limited biological activity; 2. Limited mechanical properties
Poly(lactic-ethanolic acid)⁹²	Emulsified; Electrospray	1. Adjustable physical properties; 2. High hydrophilicity	Less hydrophilic and biologically active.
Platelet-derived growth factor mimetic peptide⁷³	Electrospray	1. High biological activity; 2. Low immunogenicity; 3. Stronger stability	1. Higher production costs; 2. Limited biosafety; 3. Low mechanical strength

Table 1. Hydrogel microsphere preparation materials and their advantages and disadvantages

Raw material	Preparation method	Advantage	Disadvantage
Natural polymer hydrogel microsphere
Collagen⁶²	Emulsification	1. Cell adhesion and growth; 2. Bioactivity	1. low mechanical strength; 2. Immunogenicity risk; 3. Rapid degradation rate
Gelatin^{71, 72}	Emulsification; Microfluidics; Electrospray	1.Good biocompatibility; 2. Easy processing and low cost; 3. Functionalization and cross-linking	1. Low mechanical strength; 2. Rapid degradation rate and degradation byproducts
Chitosan⁷⁴	Emulsification; Electrospray	1. Safe degradation byproducts; 2. Antimicrobial properties	1. Allergy risk; 2. Low cellular interactions; 3. Low degradation rate
Silk fibroin^64⇓-66	Microfluidic; Electrospray	1. Cell Adhesion; 2. Good mechanical strength	1. Hydrophobicity; 2. Slower degradation rate
Chondroitin sulfate⁷⁵	Emulsified	1. Anti-inflammatory, antioxidant, regulates enzyme activity, cellular activity, and communication; 2. Negative electronegativity	1. Rapid degradation; 2. Limited mechanical strength
Fibrous protein^64⇓-66	Emulsified; Electrospray	1. Mimics natural extracellular matrixc; 2. Facilitates vascular regeneration and cytokine adhesion	1. The preparation process is complex and costly; 2. Potential for infection
Chitin⁸⁵	Emulsified	1. Good biocompatibility; 2. good biosorption properties	1. High production costs; 2. Lower mechanical properties
Synthetic hydrogel microsphere
Alginate⁸⁶	Emulsified; Microfluidic; Electrospray	1. Good biocompatibility; 2. Easy to cross-link; 3. Ease of Gelation	1. Low degradation rate; 2. Sensitivity to pH
Polylactic acid-hydroxybutyric acid copolymer⁷¹	Emulsification; Electrospray	1. High tunability; 2. Acceptable mechanical strength	1. Structural Instability; 2. Acid product
Gelatin methacrylate⁸⁷	Emulsification; Microfluidics; Electrospray	1. Adjustable mechanical properties; 2. Adjustable physicochemical properties	1. Limited mechanical behavior; 2. Complex preparation
Polycaprolactone⁸⁸	Microfluidic; Electrospray	1. Acceptable biocompatibility; 2. High mechanical strength	1. Acidic products; 2. Slow degradation rate
Cellulose compound⁸⁹	Emulsified	1. Good biocompatibility; 2. High mechanical strength and stable chemical structure	Poor flexibility and water solubility
Polyethylene glycol⁹⁰	Emulsified; Microfluidics	1.High hydrophilicity, low immunogenicity, highly biocompatible, biodegradable; 2. Easy to modify and functionalize	1. Poor biological activity; 2. Limited mechanical strength
Polyvinyl alcohol⁹¹	Emulsified; Microfluidics; Electrospray	1. High water solubility, high biocompatibility; 2. Easy to modify and functionalize.	1. Limited biological activity; 2. Limited mechanical properties
Poly(lactic-ethanolic acid)⁹²	Emulsified; Electrospray	1. Adjustable physical properties; 2. High hydrophilicity	Less hydrophilic and biologically active.
Platelet-derived growth factor mimetic peptide⁷³	Electrospray	1. High biological activity; 2. Low immunogenicity; 3. Stronger stability	1. Higher production costs; 2. Limited biosafety; 3. Low mechanical strength

Figure 2. Examples of HMS preparation techniques. (A) Batch emulsification uses immiscible liquids (e.g. water and oil) mixed together to produce hydrogel particles (HMS) that can be cross-linked to form a hydrogel. (B) Microfluidic emulsification uses a flow of immiscible liquids to create droplets that can be cross-linked to form an HMS. (C) Photolithography utilises photomasks or moulds that are used as templates for the micro-hydrogel. (D) Electrospray method uses electricity to cause the flowing solution to form charged to form droplets which can then be cross-linked to form an HMS. Created with BioRender.com. EHD: electrohydrodynamic; HMS: hydrogel microsphere; UV: ultraviolet.

Figure 3. Schematic diagram of HMS for the treatment of locomotor system diseases. Created with BioRender.com.HMS: hydrogel microspheres.

Figure 4. Different drug release characteristics of HMS in bone tissue engineering. (A) Reinforced HMS cross-linked network slow release of drugs for OA. Reprinted from He et al.121 Copyright 2022 Acta Materialia Inc. (B) Positively charged HMS system targeted release of drugs to alleviate OA. Reprinted from Lin et al.122 Copyright 2022 Wiley‐VCH GmbH. (C) MMP13-responsive HMS targeted inflammatory environment for rapid release to alleviate OA. Scale bars: 10 mm. Reprinted from Xiang et al.123 (D) Sequential release of drugs by the HMS system to modulate inflammation in osteogenesis. Reprinted from Ma et al.125 Copyright 2022 American Chemical Society. (E) Shell-nucleus structure HMS system can protect and release drugs slowly for osteoporosis. Reprinted from Li et al.128 AP: anteroposterior; Chs: chondroitin sulfate; ChsMA: chondroitin sulfate methacryloyl; COX-2: cyclooxygenase-2; CTSK: cathepsin K; EMCN: endomucin; HAMA: hyaluronic acid methacryloyl; HIF-1α: hypoxia-inducible factor 1-alpha; HO-1: heme oxygenase-1; IL-1β: interleukin-1β; iNOS: inducible nitric oxide synthase; KGN: kartogenin; LAT: lateral; Lipo: liposomes; LL37: cathelicidin LL-37; MMP: matrix metalloproteinase; N2: diatomic nitrogen; NF-κB: nuclear factor κB; NFATc1: nuclear factor of activated T-cells, cytoplasmic 1; NO: nitric oxide; NP: nanoparticle; OA: osteoarthritis; PAMAM: polyamidoamine; PBS: phosphate-buffered saline; PDAP: polyhedral oligomeric silsesquioxane/desferrioxamine@aspartic acid 8/polyethylene glycol; PEG2: prostaglandin E2; PLGA: poly(lactic-co-glycolic acid); SIS: small intestinal submucosa; TNF-α: tumour necrosis factor-α; TRAP: tartrate-resistant acid phosphatase; UV: ultraviolet; VEGF: vascular endothelial growth factor; W9: WP9QY.

Figure 5. The HMS system promotes bone regeneration by piggybacking osteogenic active factors. (A) HMS system promotes bone regeneration by trapping magnesium ions. Reprinted from Zhao et al.129 Copyright 2021 American Chemical Society. (B) HMS system promotes bone regeneration by releasing magnesium ions to further activate BMP-2 function. Reprinted from Lin et al.130 (C) HMS system regulates the DNA-to-filament protein ratio to promote bone regeneration. Reprinted from Shen et al.133 (D) HMS loads and releases BMSC-exosomes for vascularised bone regeneration. Reprinted from Yang et al.127 (E) HMS promotes bone regeneration by loading and releasing miR-218. Reprinted from Li et al.134 Copyright 2022 American Chemical Society. AIMA: alginate methacryloyl; Akt: protein kinase B; bFGF: basic fibroblast growth factor; BMP-2: bone morphogenetic protein-2; BMSC: bone marrow mesenchymal stem cell; BP: black phosphorus; DAPI: 4′,6-diamidino-2-phenylindole; ECM: extracellular matrix; GelMA: gelatine methacrylate; GMS: gelatin methacrylate microspheres; HMS: hydrogel microsphere; KLDL: Ac-KLDLKLDLVPMSMRGGKLDLKLDL-CONH2 pedtide ns: not significant; Mg2+: magnesium ion; MMP: matrix metalloproteinase; NP: nucleus pulposus; ns: not significant; OCN: osteocalcin; p-Akt: phosphorylated protein kinase B; PEI: polyethyleneimine; Pep-RGDfKAC: peptide sequence of Arg-Gly-Asp with an acryloyl group; PLGA: poly(lactic-co-glycolic acid); PPP: poly(lactide-co-glycolide)-g-polyethylenimine-b-polyethy-lene; RGD: Arg-Gly-Asp peptide; RGI: Arg-Gly-Iso peptide; RUNX2: Runt-related transcription factor 2; SF-DNA: silk fibroin-DNA; SilMA: silk fibroin methacryloyl; UV: ultraviolet; α-SMA: α-smooth muscle actin.

Figure 6. HMS and cell co-culture system. (A) 3D structure of HMS surface promotes the proliferation and differentiation of BMSCs. Reprinted from Sulaiman et al.139 (B) Modulation of elastic modulus of HMS surface induces the differentiation of intervertebral disc progenitor cells. *P < 0.05, **P < 0.01, ***P < 0.001. Reprinted from Chen et al.140 Copyright 2023 Wiley‐VCH GmbH. (C) Modulation of the porosity of HMS surface enhances the proliferation and adhesion ability of BMSCs and HUVECs. Reprinted from Yuan et al.142 Copyright 2021 Wiley‐VCH GmbH. (D) Promotion of vascularised bone regeneration by piggybacking BMSCs and HUVECs in and on HMS, respectively. Reprinted from Zhong et al.143 Copyright 2017 American Chemical Society. Acan: aggrecan; Adamts: a disintegrin and metalloproteinase with thrombospondin motifs; bFGF: basic fibroblast growth factor; BMSC: bone marrow mesenchymal stem cell; CMS: cryogel microsphere; Col 1: collagen I; DI: deionized; ECM: extracellular matrix; GelMA: gelatine methacrylate; GM: gelatine microsphere; HMS: hydrogel microsphere; HUVEC: human umbilical vein endothelial cell; MMP 13: matrix metalloproteinase-13; NCAM-1: neural cell adhesion molecule 1; NP: nucleus pulposus; NPC: nucleus pulposus cells; OD: optical density; SEM: scanning electron microscope; Soft-H: group of high modulus of elasticity and high ligand density; Soft-L: group of low modulus of elasticity and low ligand density; Stiff-H: group of high modulus of elasticity and high ligand density; Stiff-L: group of high modulus of elasticity and low ligand density; Timp3: tissue inhibitor of metalloproteinases 3; Ultrasoft-H: group of very low modulus of elasticity and high ligand density; Ultrasoft-L: group of very low modulus of elasticity and low ligand density; UV: ultraviolet; YAP: yes-associated protein.

Figure 7. HMS scaffolds. (A) composite PLGA-PEG-PLGA microsphere scaffolds piggybacking VEGF with DPSC-exosomes to promote vascularised osteogenesis. Reprinted from Han et al.150 Copyright 2023 Elsevier B.V. (B) Electrostatically self-assembled BP/CS microsphere scaffolds. Reprinted from Luo et al.156 Copyright 2023 Wiley‐VCH GmbH. (C) 3D printed Gel/GelMA microsphere scaffold. Reprinted from Seymour et al.157 Copyright 2021 Wiley‐VCH GmbH. 3D: three-dimensional; bFGF: basic fibroblast growth factor; BP: bisphosphonate; CS: chitosan methacrylate; DPSC: dental pulp stem cell; Exo: exosome; Gel: gelatine; GelMA: gelatine methacrylate; HA: hyaluronic acid; HMS: hydrogel microsphere; ns: not significant; PEG: polyethylene glycol; PLGA: poly(lactic-co-glycolic acid); UV: ultraviolet; VEGF: vascular endothelial growth factor.

Figure 8. HMS modulates the immune microenvironment of bone regeneration. (A) GMNP microspheres inhibit ROS and improve the inflammatory microenvironment. Reprinted from Zheng et al.165 Copyright 2023 Wiley‐VCH GmbH. (B) BP/GelMA microspheres induce M2 macrophage polarisation by electrical stimulation to modulate the immune microenvironment. Reprinted from Sun et al.167 Copyright 2023 Wiley‐VCH GmbH. (C) Li-gel/MS/TGF-β1 microspheres induce M2 macrophage polarisation to modulate the immune microenvironment. Reprinted from Li et al.168 Copyright 2022 Published by Elsevier B.V. *P < 0.05, #P < 0.05. AKT: protein kinase B; ARG-1: arginase-1; BMP: bone morphogenetic protein; BMSC: bone marrow stromal cell; BP: bisphosphonate; CAT: catalase; CCR7: chemokine receptor 7; COL-2: collagen II; EC: endothelial cell; GelMA: gelatine methacrylate; GMNP: hydrogen ion-capturing hydrogel microspheres; HMS: hydrogel microsphere; IL-1β: interleukin-1beta; Li-gel: lithium heparin hydrogel; MMP: matrix metalloproteinase; MNPCAT: catalase-loaded mineralised nanoparticles; MS: microsphere; NLRP: NOD-like receptor protein; PDGF: platelet-derived growth factor; ROS: reactive oxygen species; smad: small mother against decapentaplegic homolog; TGF-β: transforming growth factor β; TXNIP: thioredoxin-interacting protein; US: ultrasound; VEC: vascular endothelial cell; VEGF: vascular endothelial growth factor.

Figure 9. The HMS system promotes nerve regeneration. (A) RIBQ composite microspheres promote neural-vascularised osteogenesis. *P < 0.05, **P < 0.01, ***P < 0.001. Reprinted from Li et al.172 Copyright 2023 Royal Society of Chemistry. (B) bFGF/GelMA microspheres promote proliferation and differentiation of neural stem cells. Reprinted from Chen et al.173 bFGF: basic fibroblast growth factor; BFP-1: bone-forming peptide-1; BV/TV: bone volume to total volume; EDC/NHS: N‐(3‐Dimethylaminopropyl)‐N′‐ethylcarbodiimide hydrochloride/N‐hydroxy succinimide; GelMA: gelatine methacrylate; GM: gelatine microsphere; IK19: Ac-CSRARKQAASIKVAVSADR-NH2 peptide; MSC: mesenchymal stem cell; MSN: mesoporous silica nanoparticles; QK: Ac-KLTWQELYQLKYKGI-NH2 peptide; QK/GM: QK-loaded gelatin microspheres; RA/C: cell-laden and RGD peptide grafted alginate hydrogel; RGD: Arg-Gly-Asp peptide; RIBQ: hydrogel-microsphere composites; Tb.N: trabecular number; Tb.Sp: trabecular separation; UV; ultraviolet.

Figure 10. The HMS system regulates functional cells of the bone lineage. (A) Cerium-ion loaded GelMA microspheres activate the Wnt/β-catenin pathway to promote bone regeneration. Reprinted from Liu et al.178 (B) HMS system loaded with microRNA-29a activates the BMP pathway to promote vascularised bone regeneration. *P < 0.05, **P < 0.01, ***P < 0.001. Reprinted from Pan et al.185 Copyright 2023 Wiley‐VCH GmbH. (C) Microspheres promote bone regeneration by restoring the redox homeostasis of BMSCs. Reprinted from Yang et al.189 *P < 0.05, vs. Ful 0 group; #P < 0.05, vs. Ful 10 group. ALP: alkaline phosphatase; BMP: bone morphogenetic protein; BMSC: bone marrow mesenchymal stem cell; COL1/COL-1: collagen I; DCFH-DA: 2′,7′-dichlorodihydrofluorescein diacetate; EC: endothelial cell; Exo: exosome; FMS: fullerol-hydrogel microfluidic sphere; Ful: fullerol; GelMA: gelatine methacrylate; HB-PEGDA: hyperbranched poly ethylene glycol diacrylate; HDAC4: histone deacetylase 4; HMP: hydrogel microparticle; HMS: hydrogel microsphere; HUVEC: human umbilical vein endothelial cell; LRP5/6: low-density lipoprotein receptor-related protein 5/6; ns: not significant; OCN: osteocalcin; P-GelMA-Ce: phosphorylated gelatin methacrylamide-cerium composite microspheres; RGD: Arg-Gly-Asp; Runx2: Runt-related transcription factor 2; SD: Sprague-Dawley; SH-HA: sulfhydryl-modified hyaluronic acid; TCF: T-cell factor; VEGF: vascular endothelial growth factor.

References 197

1.	Jonitz, A.; Lochner, K.; Lindner, T.; Hansmann, D.; Marrot, A.; Bader, R. Oxygen consumption, acidification and migration capacity of human primary osteoblasts within a three-dimensional tantalum scaffold. J Mater Sci Mater Med. 2011, 22, 2089-2095.
2.	Wang, H.; Zheng, X.; Zhang, Y.; Huang, J.; Zhou, W.; Li, X.; Tian, H.; Wang, B.; Xing, D.; Fu, W.; Chen, T.; Wang, X.; Zhang, X.; Wu, A. The endocrine role of bone: Novel functions of bone-derived cytokines. Biochem Pharmacol. 2021, 183, 114308.
3.	Schmitz, J. P.; Hollinger, J. O. The critical size defect as an experimental model for craniomandibulofacial nonunions. Clin Orthop Relat Res. 1986, 299-308.
4.	Petite, H.; Viateau, V.; Bensaïd, W.; Meunier, A.; de Pollak, C.; Bourguignon, M.; Oudina, K.; Sedel, L.; Guillemin, G. Tissue-engineered bone regeneration. Nat Biotechnol. 2000, 18, 959-963.
5.	Hao, S.; Wang, M.; Yin, Z.; Jing, Y.; Bai, L.; Su, J. Microenvironment-targeted strategy steers advanced bone regeneration. Mater Today Bio. 2023, 22, 100741.
6.	Miller, C. P.; Chiodo, C. P. Autologous bone graft in foot and ankle surgery. Foot Ankle Clin. 2016, 21, 825-837.
7.	Zhang, L.; Zhang, J.; Liang, D.; Ling, H.; Zhang, Y.; Liu, Y.; Chen, X. Clinical study on minimally invasive treatment of femoral head necrosis with two different bone graft materials. Int Orthop. 2021, 45, 585-591.
8.	Resende, R. F. B.; Sartoretto, S. C.; Uzeda, M. J.; Alves, A.; Calasans-Maia, J. A.; Rossi, A. M.; Granjeiro, J. M.; Calasans-Maia, M. D. Randomized controlled clinical trial of nanostructured carbonated hydroxyapatite for alveolar bone repair. Materials (Basel). 2019, 12.
9.	Schaaf, H.; Lendeckel, S.; Howaldt, H. P.; Streckbein, P. Donor site morbidity after bone harvesting from the anterior iliac crest. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010, 109, 52-58.
10.	Li, Y.; Wang, J.; Wang, Y.; Du, W.; Wang, S. Transplantation of copper-doped calcium polyphosphate scaffolds combined with copper (II) preconditioned bone marrow mesenchymal stem cells for bone defect repair. J Biomater Appl. 2018, 32, 738-753.
11.	Wang, X.; Ma, Y.; Lu, F.; Chang, Q. The diversified hydrogels for biomedical applications and their imperative roles in tissue regeneration. Biomater Sci. 2023, 11, 2639-2660.
12.	Daly, A. C.; Riley, L.; Segura, T.; Burdick, J. A. Hydrogel microparticles for biomedical applications. Nat Rev Mater. 2020, 5, 20-43.
13.	Miao, K.; Zhou, Y.; He, X.; Xu, Y.; Zhang, X.; Zhao, H.; Zhou, X.; Gu, Q.; Yang, H.; Liu, X.; Huang, L.; Shi, Q. Microenvironment-responsive bilayer hydrogel microspheres with gelatin-shell for osteoarthritis treatment. Int J Biol Macromol. 2024, 261, 129862.
14.	Sun, Z.; Song, C.; Wang, C.; Hu, Y.; Wu, J. Hydrogel-based controlled drug delivery for cancer treatment: a review. Mol Pharm. 2020, 17, 373-391.
15.	Zhao, Y.; Peng, X.; Wang, Q.; Zhang, Z.; Wang, L.; Xu, Y.; Yang, H.; Bai, J.; Geng, D. Crosstalk between the neuroendocrine system and bone homeostasis. Endocr Rev. 2024, 45, 95-124.
16.	Zhang, J.; Pan, J.; Jing, W. Motivating role of type H vessels in bone regeneration. Cell Prolif. 2020, 53, e12874.
17.	Chen, W.; Jin, X.; Wang, T.; Bai, R.; Shi, J.; Jiang, Y.; Tan, S.; Wu, R.; Zeng, S.; Zheng, H.; Jia, H.; Li, S. Ginsenoside Rg1 interferes with the progression of diabetic osteoporosis by promoting type H angiogenesis modulating vasculogenic and osteogenic coupling. Front Pharmacol. 2022, 13, 1010937.
18.	Zhao, Y.; Richardson, K.; Yang, R.; Bousraou, Z.; Lee, Y. K.; Fasciano, S.; Wang, S. Notch signaling and fluid shear stress in regulating osteogenic differentiation. Front Bioeng Biotechnol. 2022, 10, 1007430.
19.	Zhou, Y.; Guo, P.; Jin, Z.; Chai, M.; Zhang, S.; Wang, X.; Tan, W. S.; Zhou, Y. Fluid shear force and hydrostatic pressure jointly promote osteogenic differentiation of BMSCs by activating YAP1 and NFAT2. Biotechnol J. 2024, 19, e2300714.
20.	Wicki, S.; Gurzeler, U.; Wei-Lynn Wong, W.; Jost, P. J.; Bachmann, D.; Kaufmann, T. Loss of XIAP facilitates switch to TNFα-induced necroptosis in mouse neutrophils. Cell Death Dis. 2016, 7, e2422.
21.	Wu, M.; Wu, S.; Chen, W.; Li, Y. P. The roles and regulatory mechanisms of TGF-β and BMP signaling in bone and cartilage development, homeostasis and disease. Cell Res. 2024, 34, 101-123.
22.	Li, X. D.; Hong, M. N.; Chen, J.; Lu, Y. Y.; Ye, M. Q.; Ma, Y.; Zhu, D. L.; Gao, P. J. Adventitial fibroblast-derived vascular endothelial growth factor promotes vasa vasorum-associated neointima formation and macrophage recruitment. Cardiovasc Res. 2020, 116, 708-720.
23.	Ando, Y.; Tsukasaki, M.; Huynh, N. C.; Zang, S.; Yan, M.; Muro, R.; Nakamura, K.; Komagamine, M.; Komatsu, N.; Okamoto, K.; Nakano, K.; Okamura, T.; Yamaguchi, A.; Ishihara, K.; Takayanagi, H. The neutrophil-osteogenic cell axis promotes bone destruction in periodontitis. Int J Oral Sci. 2024, 16, 18.
24.	Paroli, M.; Caccavale, R.; Fiorillo, M. T.; Spadea, L.; Gumina, S.; Candela, V.; Paroli, M. P. The double game played by Th17 cells in infection: host defense and immunopathology. Pathogens. 2022, 11, 1547.
25.	Rizwan, H.; Pal, S.; Sabnam, S.; Pal, A. High glucose augments ROS generation regulates mitochondrial dysfunction and apoptosis via stress signalling cascades in keratinocytes. Life Sci. 2020, 241, 117148.
26.	Rabbi, M. F.; Eissa, N.; Munyaka, P. M.; Kermarrec, L.; Elgazzar, O.; Khafipour, E.; Bernstein, C. N.; Ghia, J. E. Reactivation of intestinal inflammation is suppressed by catestatin in a murine model of colitis via M1 macrophages and not the gut microbiota. Front Immunol. 2017, 8, 985.
27.	Zhou, X.; Zhang, Z.; Jiang, W.; Hu, M.; Meng, Y.; Li, W.; Zhou, X.; Wang, C. Naringenin is a potential anabolic treatment for bone loss by modulating osteogenesis, osteoclastogenesis, and macrophage polarization. Front Pharmacol. 2022, 13, 872188.
28.	Maschalidi, S.; Mehrotra, P.; Keçeli, B. N.; De Cleene, H. K. L.; Lecomte, K.; Van der Cruyssen, R.; Janssen, P.; Pinney, J.; van Loo, G.; Elewaut, D.; Massie, A.; Hoste, E.; Ravichandran, K. S. Targeting SLC7A11 improves efferocytosis by dendritic cells and wound healing in diabetes. Nature. 2022, 606, 776-784.
29.	Park, J. H.; Seo, Y. J.; Oh, H. S.; Byun, J. H. Effects of myeloid immune cells on the metabolic process of biomimetic bone regeneration. Life Sci. 2023, 334, 122251.
30.	Sun, W.; Ye, B.; Chen, S.; Zeng, L.; Lu, H.; Wan, Y.; Gao, Q.; Chen, K.; Qu, Y.; Wu, B.; Lv, X.; Guo, X. Neuro-bone tissue engineering: emerging mechanisms, potential strategies, and current challenges Bone Res. 2023, 11, 65.
31.	Bolamperti, S.; Guidobono, F.; Rubinacci, A.; Villa, I. The role of growth hormone in mesenchymal stem cell commitment. Int J Mol Sci. 2019, 20, 5264.
32.	Zhang, Z.; Hu, P.; Wang, Z.; Qiu, X.; Chen, Y. BDNF promoted osteoblast migration and fracture healing by up-regulating integrin β1 via TrkB-mediated ERK1/2 and AKT signalling. J Cell Mol Med. 2020, 24, 10792-10802.
33.	Xia, W.; Xie, J.; Cai, Z.; Liu, X.; Wen, J.; Cui, Z. K.; Zhao, R.; Zhou, X.; Chen, J.; Mao, X.; Gu, Z.; Zou, Z.; Zou, Z.; Zhang, Y.; Zhao, M.; Mac, M.; Song, Q.; Bai, X. Damaged brain accelerates bone healing by releasing small extracellular vesicles that target osteoprogenitors. Nat Commun. 2021, 12, 6043.
34.	Tao, R.; Mi, B.; Hu, Y.; Lin, S.; Xiong, Y.; Lu, X.; Panayi, A. C.; Li, G.; Liu, G. Hallmarks of peripheral nerve function in bone regeneration. Bone Res. 2023, 11, 6.
35.	Chen, M.; Lu, L.; Cheng, D.; Zhang, J.; Liu, X.; Zhang, J.; Zhang, T. Icariin promotes osteogenic differentiation in a cell model with NF1 gene knockout by activating the cAMP/PKA/CREB pathway. Molecules. 2023, 28, 5128.
36.	Wan, Q. Q.; Qin, W. P.; Ma, Y. X.; Shen, M. J.; Li, J.; Zhang, Z. B.; Chen, J. H.; Tay, F. R.; Niu, L. N.; Jiao, K. Crosstalk between bone and nerves within bone. Adv Sci (Weinh). 2021, 8, 2003390.
37.	Ikebuchi, Y.; Aoki, S.; Honma, M.; Hayashi, M.; Sugamori, Y.; Khan, M.; Kariya, Y.; Kato, G.; Tabata, Y.; Penninger, J. M.; Udagawa, N.; Aoki, K.; Suzuki, H. Coupling of bone resorption and formation by RANKL reverse signalling. Nature. 2018, 561, 195-200.
38.	Nakamura, H.; Sato, G.; Hirata, A.; Yamamoto, T. Immunolocalization of matrix metalloproteinase-13 on bone surface under osteoclasts in rat tibia. Bone. 2004, 34, 48-56.
39.	Kibe, T.; Fuchigami, T.; Kishida, M.; Iijima, M.; Ishihata, K.; Hijioka, H.; Miyawaki, A.; Semba, I.; Nakamura, N.; Kiyono, T.; Kishida, S. A novel ameloblastoma cell line (AM-3) secretes MMP-9 in response to Wnt-3a and induces osteoclastogenesis. Oral Surg Oral Med Oral Pathol Oral Radiol. 2013, 115, 780-788.
40.	Hong, W.; Zhang, W. Hesperidin promotes differentiation of alveolar osteoblasts via Wnt/β-Catenin signaling pathway. J Recept Signal Transduct Res. 2020, 40, 442-448.
41.	Lin, X.; Patil, S.; Gao, Y. G.; Qian, A. The bone extracellular matrix in bone formation and regeneration. Front Pharmacol. 2020, 11, 757.
42.	Lin, G. L.; Hankenson, K. D. Integration of BMP, Wnt, and notch signaling pathways in osteoblast differentiation. J Cell Biochem. 2011, 112, 3491-3501.
43.	Pieralice, S.; Vigevano, F.; Del Toro, R.; Napoli, N.; Maddaloni, E. Lifestyle management of diabetes: implications for the bone-vascular axis. Curr Diab Rep. 2018, 18, 84.
44.	Yu, H.; Huang, C.; Kong, X.; Ma, J.; Ren, P.; Chen, J.; Zhang, X.; Luo, H.; Chen, G. Nanoarchitectonics of cartilage-targeting hydrogel microspheres with reactive oxygen species responsiveness for the repair of osteoarthritis. ACS Appl Mater Interfaces. 2022, 14, 40711-40723.
45.	Mendes, L. F.; Katagiri, H.; Tam, W. L.; Chai, Y. C.; Geris, L.; Roberts, S. J.; Luyten, F. P. Advancing osteochondral tissue engineering: bone morphogenetic protein, transforming growth factor, and fibroblast growth factor signaling drive ordered differentiation of periosteal cells resulting in stable cartilage and bone formation in vivo. Stem Cell Res Ther. 2018, 9, 42.
46.	Kang, F.; Yi, Q.; Gu, P.; Dong, Y.; Zhang, Z.; Zhang, L.; Bai, Y. Controlled growth factor delivery system with osteogenic-angiogenic coupling effect for bone regeneration. J Orthop Translat. 2021, 31, 110-125.
47.	Tomlinson, R. E.; Li, Z.; Zhang, Q.; Goh, B. C.; Li, Z.; Thorek, D. L. J.; Rajbhandari, L.; Brushart, T. M.; Minichiello, L.; Zhou, F.; Venkatesan, A.; Clemens, T. L. NGF-TrkA signaling by sensory nerves coordinates the vascularization and ossification of developing endochondral bone. Cell Rep. 2016, 16, 2723-2735.
48.	Guan, Y.; Niu, H.; Liu, Z.; Dang, Y.; Shen, J.; Zayed, M.; Ma, L.; Guan, J. Sustained oxygenation accelerates diabetic wound healing by promoting epithelialization and angiogenesis and decreasing inflammation. Sci Adv. 2021, 7, eabj0153.
49.	Fliefel, R.; Popov, C.; Tröltzsch, M.; Kühnisch, J.; Ehrenfeld, M.; Otto, S. Mesenchymal stem cell proliferation and mineralization but not osteogenic differentiation are strongly affected by extracellular pH. J Craniomaxillofac Surg. 2016, 44, 715-724.
50.	Qi, H.; Wang, B.; Wang, M.; Xie, H.; Chen, C. A pH/ROS-responsive antioxidative and antimicrobial GelMA hydrogel for on-demand drug delivery and enhanced osteogenic differentiation in vitro. Int J Pharm. 2024, 657, 124134.
51.	Kang, Z.; Wu, B.; Zhang, L.; Liang, X.; Guo, D.; Yuan, S.; Xie, D. Metabolic regulation by biomaterials in osteoblast. Front Bioeng Biotechnol. 2023, 11, 1184463.
52.	Ravoor, J.; Thangavel, M.; Elsen, S. R. Comprehensive review on design and manufacturing of bio-scaffolds for bone reconstruction. ACS Appl Bio Mater. 2021, 4, 8129-8158.
53.	Chen, X.; Yan, J.; He, F.; Zhong, D.; Yang, H.; Pei, M.; Luo, Z. P. Mechanical stretch induces antioxidant responses and osteogenic differentiation in human mesenchymal stem cells through activation of the AMPK-SIRT1 signaling pathway. Free Radic Biol Med. 2018, 126, 187-201.
54.	Zhang, X.; Liu, X.; Pan, L.; Lee, I. Magnetic fields at extremely low-frequency (50 Hz, 0.8 mT) can induce the uptake of intracellular calcium levels in osteoblasts. Biochem Biophys Res Commun. 2010, 396, 662-666.
55.	Feng, Q.; Zhou, X.; He, C. NIR light-facilitated bone tissue engineering. Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2024, 16, e1925.
56.	Peng, J.; Zhao, J.; Tang, Q.; Wang, J.; Song, W.; Lu, X.; Huang, X.; Chen, G.; Zheng, W.; Zhang, L.; Han, Y.; Yan, C.; Wan, Q.; Chen, L. Low intensity near-infrared light promotes bone regeneration via circadian clock protein cryptochrome 1. Int J Oral Sci. 2022, 14, 53.
57.	Wu, C.; Sun, Y.; He, X.; Weng, W.; Cheng, K.; Chen, Z. Photothermal extracellular matrix based nanocomposite films and their effect on the osteogenic differentiation of BMSCs. Nanoscale. 2023, 15, 5379-5390.
58.	Hu, Z. C.; Lu, J. Q.; Zhang, T. W.; Liang, H. F.; Yuan, H.; Su, D. H.; Ding, W.; Lian, R. X.; Ge, Y. X.; Liang, B.; Dong, J.; Zhou, X. G.; Jiang, L. B. Piezoresistive MXene/silk fibroin nanocomposite hydrogel for accelerating bone regeneration by re-establishing electrical microenvironment. Bioact Mater. 2023, 22, 1-17.
59.	Lei, C.; Lei, J.; Zhang, X.; Wang, H.; He, Y.; Zhang, W.; Tong, B.; Yang, C.; Feng, X. Heterostructured piezocatalytic nanoparticles with enhanced ultrasound response for efficient repair of infectious bone defects. Acta Biomater. 2023, 172, 343-354.
60.	Miyasaka, M.; Nakata, H.; Hao, J.; Kim, Y. K.; Kasugai, S.; Kuroda, S. Low-intensity pulsed ultrasound stimulation enhances heat-shock protein 90 and mineralized nodule formation in mouse calvaria-derived osteoblasts. Tissue Eng Part A. 2015, 21, 2829-2839.
61.	Manaka, S.; Tanabe, N.; Kariya, T.; Naito, M.; Takayama, T.; Nagao, M.; Liu, D.; Ito, K.; Maeno, M.; Suzuki, N.; Miyazaki, M. Low-intensity pulsed ultrasound-induced ATP increases bone formation via the P2X7 receptor in osteoblast-like MC3T3-E1 cells. FEBS Lett. 2015, 589, 310-318.
62.	Zhao, L.; Zhou, Y.; Zhang, J.; Liang, H.; Chen, X.; Tan, H. Natural polymer-based hydrogels: from polymer to biomedical applications. Pharmaceutics. 2023, 15, 2514.
63.	Xu, Q.; Torres, J. E.; Hakim, M.; Babiak, P. M.; Pal, P.; Battistoni, C. M.; Nguyen, M.; Panitch, A.; Solorio, L.; Liu, J. C. Collagen- and hyaluronic acid-based hydrogels and their biomedical applications. Mater Sci Eng R Rep. 2021, 146, 100641.
64.	Wang, J.; Sun, X.; Zhang, Z.; Wang, Y.; Huang, C.; Yang, C.; Liu, L.; Zhang, Q. Silk fibroin/collagen/hyaluronic acid scaffold incorporating pilose antler polypeptides microspheres for cartilage tissue engineering. Mater Sci Eng C Mater Biol Appl. 2019, 94, 35-44.
65.	Wang, Z.; Yin, X.; Zhuang, C.; Wu, K.; Wang, H.; Shao, Z.; Tian, B.; Lin, H. Injectable regenerated silk fibroin micro/nanosphere with enhanced permeability and stability for osteoarthritis therapy. Small. 2024, e2405049.
66.	Wang, J.; Yang, Q.; Cheng, N.; Tao, X.; Zhang, Z.; Sun, X.; Zhang, Q. Collagen/silk fibroin composite scaffold incorporated with PLGA microsphere for cartilage repair. Mater Sci Eng C Mater Biol Appl. 2016, 61, 705-711.
67.	Ciocci, M.; Cacciotti, I.; Seliktar, D.; Melino, S. Injectable silk fibroin hydrogels functionalized with microspheres as adult stem cells-carrier systems. Int J Biol Macromol. 2018, 108, 960-971.
68.	Pradhan, S.; Clary, J. M.; Seliktar, D.; Lipke, E. A. A three-dimensional spheroidal cancer model based on PEG-fibrinogen hydrogel microspheres. Biomaterials. 2017, 115, 141-154.
69.	Lee, J. S.; Hur, W. Cellular uptake and fate of fibroin microspheres loaded with randomly fragmented DNA in 3T3 cells. Int J Nanomedicine. 2016, 11, 2069-2079.
70.	Hayashi, K.; Tabata, Y. Preparation of stem cell aggregates with gelatin microspheres to enhance biological functions. Acta Biomater. 2011, 7, 2797-2803.
71.	Bello, A. B.; Kim, D.; Kim, D.; Park, H.; Lee, S. H. Engineering and functionalization of gelatin biomaterials: from cell culture to medical applications. Tissue Eng Part B Rev. 2020, 26, 164-180.
72.	Battogtokh, G.; Joo, Y.; Abuzar, S. M.; Park, H.; Hwang, S. J. Gelatin coating for the improvement of stability and cell uptake of hydrophobic drug-containing liposomes. Molecules. 2022, 27, 1041.
73.	Gao, Y.; Ma, Q. Bacterial infection microenvironment-responsive porous microspheres by microfluidics for promoting anti-infective therapy. Smart Med. 2022, 1, e20220012.
74.	Wu, M. Y.; Liang, Y. H.; Yen, S. K. Effects of chitosan on loading and releasing for doxorubicin loaded porous hydroxyapatite-gelatin composite microspheres. Polymers (Basel). 2022, 14, 4276.
75.	Schuurmans, C. C. L.; Mihajlovic, M.; Hiemstra, C.; Ito, K.; Hennink, W. E.; Vermonden, T. Hyaluronic acid and chondroitin sulfate (meth)acrylate-based hydrogels for tissue engineering: Synthesis, characteristics and pre-clinical evaluation. Biomaterials. 2021, 268, 120602.
76.	Hong, Y.; Duan, Y.; Zhu, Z.; Yu, Q.; Mo, Z.; Wang, H.; Zhou, T.; Liu, Z.; Bai, J.; Zhang, X.; Yang, H.; Zhu, C.; Li, B. IL-1ra loaded chondroitin sulfate-functionalized microspheres for minimally invasive treatment of intervertebral disc degeneration. Acta Biomater. 2024. doi: 10.1016/j.actbio.2024.06.048.
77.	Guo, L.; Chen, H.; Li, Y.; Zhou, J.; Chen, J. Biocompatible scaffolds constructed by chondroitin sulfate microspheres conjugated 3D-printed frameworks for bone repair. Carbohydr Polym. 2023, 299, 120188.
78.	Bashir, S.; Hina, M.; Iqbal, J.; Rajpar, A. H.; Mujtaba, M. A.; Alghamdi, N. A.; Wageh, S.; Ramesh, K.; Ramesh, S. Fundamental concepts of hydrogels: synthesis, properties, and their applications. Polymers (Basel). 2020, 12, 2702.
79.	Park, J. S.; Yang, H. N.; Jeon, S. Y.; Woo, D. G.; Na, K.; Park, K. H. Osteogenic differentiation of human mesenchymal stem cells using RGD-modified BMP-2 coated microspheres. Biomaterials. 2010, 31, 6239-6248.
80.	Zolnik, B. S.; Burgess, D. J. Effect of acidic pH on PLGA microsphere degradation and release. J Control Release. 2007, 122, 338-344.
81.	Guo, J.; Meng, L.; Wang, H.; Zhao, K.; Ding, Q.; Sun, L. Recent advances in gelatin methacryloyl hydrogels for bone regeneration. ACS Appl Nano Mater. 2024, 7, 17193-17213.
82.	Xu, J.; Wang, Y.; Li, Z.; Tian, Y.; Li, Z.; Lu, A.; Hsu, C. Y.; Negri, S.; Tang, C.; Tower, R. J.; Morris, C.; James, A. W. PDGFRα reporter activity identifies periosteal progenitor cells critical for bone formation and fracture repair. Bone Res. 2022, 10, 7.
83.	Zhang, M.; Yu, W.; Niibe, K.; Zhang, W.; Egusa, H.; Tang, T.; Jiang, X. The effects of platelet-derived growth factor-BB on bone marrow stromal cell-mediated vascularized bone regeneration. Stem Cells Int. 2018, 2018, 3272098.
84.	Wu, W.; Jia, S.; Xu, H.; Gao, Z.; Wang, Z.; Lu, B.; Ai, Y.; Liu, Y.; Liu, R.; Yang, T.; Luo, R.; Hu, C.; Kong, L.; Huang, D.; Yan, L.; Yang, Z.; Zhu, L.; Hao, D. Supramolecular hydrogel microspheres of platelet-derived growth factor mimetic peptide promote recovery from spinal cord injury. ACS Nano. 2023, 17, 3818-3837.
85.	Liao, J.; Zhou, Y.; Zhao, X.; Hou, B.; Zhang, J.; Huang, H. Chitin microspheres: From fabrication to applications. Carbohydr Polym. 2024, 329, 121773.
86.	Liu, X.; Wang, Y.; Liang, Z.; Lian, X.; Huang, D.; Hu, Y.; Wei, Y. Progress in preparation and application of sodium alginate microspheres. Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2023, 40, 792-798.
87.	Shao, L.; Pan, B.; Hou, R.; Jin, Y.; Yao, Y. User-friendly microfluidic manufacturing of hydrogel microspheres with sharp needle. Biofabrication. 2022, 14, 025017.
88.	Seyyed Nasrollah, S. A.; Karimi-Soflou, R.; Karkhaneh, A. Photo-click crosslinked hydrogel containing MgO2-loaded PLGA microsphere with concurrent magnesium and oxygen release for bone tissue engineering. Mater Today Chem. 2023, 28, 101389.
89.	Jo, S.; Park, S.; Oh, Y.; Hong, J.; Kim, H. J.; Kim, K. J.; Oh, K. K.; Lee, S. H. Development of cellulose hydrogel microspheres for lipase immobilization. Biotechnol Bioproc E. 2019, 24, 145-154.
90.	Xin, S.; Chimene, D.; Garza, J. E.; Gaharwar, A. K.; Alge, D. L. Clickable PEG hydrogel microspheres as building blocks for 3D bioprinting. Biomater Sci. 2019, 7, 1179-1187.
91.	Zhang, M. K.; Zhang, X. H.; Han, G. Z. Magnetic alginate/PVA hydrogel microspheres with selective adsorption performance for aromatic compounds. Sep Purif Technol. 2021, 278, 119547.
92.	DiStefano, T. J.; Vaso, K.; Panebianco, C. J.; Danias, G.; Chionuma, H. N.; Kunnath, K.; Karoulias, S. Z.; Wang, M.; Xu, P.; Davé R. N.; Sahoo, S.; Weiser, J. R.; Iatridis, J. C. Hydrogel-embedded poly(lactic-co-glycolic acid) microspheres for the delivery of hMSC-derived exosomes to promote bioactive annulus fibrosus repair. Cartilage. 2022, 13, 19476035221113959.
93.	Franco, C. L.; Price, J.; West, J. L. Development and optimization of a dual-photoinitiator, emulsion-based technique for rapid generation of cell-laden hydrogel microspheres. Acta Biomater. 2011, 7, 3267-3276.
94.	Leong, W.; Lau, T. T.; Wang, D. A. A temperature-cured dissolvable gelatin microsphere-based cell carrier for chondrocyte delivery in a hydrogel scaffolding system. Acta Biomater. 2013, 9, 6459-6467.
95.	De Geest, B. G.; Urbanski, J. P.; Thorsen, T.; Demeester, J.; De Smedt, S. C. Synthesis of monodisperse biodegradable microgels in microfluidic devices. Langmuir. 2005, 21, 10275-10279.
96.	Pittermannová A.; Ruberová Z.; Zadražil, A.; Bremond, N.; Bibette, J.; Štěpánek, F. Microfluidic fabrication of composite hydrogel microparticles in the size range of blood cells. RSC Adv. 2016, 6, 103532-103540.
97.	Jiang, W.; Li, M.; Chen, Z.; Leong, K. W. Cell-laden microfluidic microgels for tissue regeneration. Lab Chip. 2016, 16, 4482-4506.
98.	Selimović S.; Oh, J.; Bae, H.; Dokmeci, M.; Khademhosseini, A. Microscale strategies for generating cell-encapsulating hydrogels. Polymers (Basel). 2012, 4, 1554.
99.	Headen, D. M.; García, J. R.; García, A. J. Parallel droplet microfluidics for high throughput cell encapsulation and synthetic microgel generation. Microsyst Nanoeng. 2018, 4, 17076.
100.	Wang, Q.; Wang, C.; Yang, X.; Wang, J.; Zhang, Z.; Shang, L. Microfluidic preparation of optical sensors for biomedical applications. Smart Med. 2023, 2, e20220027.
101.	Yang, J.; Han, Y.; Lin, J.; Zhu, Y.; Wang, F.; Deng, L.; Zhang, H.; Xu, X.; Cui, W. Ball-bearing-inspired polyampholyte-modified microspheres as bio-lubricants attenuate osteoarthritis. Small. 2020, 16, e2004519.
102.	Lee, S. A.; Chung, S. E.; Park, W.; Lee, S. H.; Kwon, S. Three-dimensional fabrication of heterogeneous microstructures using soft membrane deformation and optofluidic maskless lithography. Lab Chip. 2009, 9, 1670-1675.
103.	Nichol, J. W.; Koshy, S. T.; Bae, H.; Hwang, C. M.; Yamanlar, S.; Khademhosseini, A. Cell-laden microengineered gelatin methacrylate hydrogels. Biomaterials. 2010, 31, 5536-5544.
104.	Helgeson, M. E.; Chapin, S. C.; Doyle, P. S. Hydrogel microparticles from lithographic processes: novel materials for fundamental and applied colloid science. Curr Opin Colloid Interface Sci. 2011, 16, 106-117.
105.	Lin, F.; Li, Y.; Cui, W. Injectable hydrogel microspheres in cartilage repair. Biomed Technol. 2023, 1, 18-29.
106.	Mehregan Nikoo, A.; Kadkhodaee, R.; Ghorani, B.; Razzaq, H.; Tucker, N. Controlling the morphology and material characteristics of electrospray generated calcium alginate microhydrogels. J Microencapsul. 2016, 33, 605-612.
107.	Pancholi, K.; Ahras, N.; Stride, E.; Edirisinghe, M. Novel electrohydrodynamic preparation of porous chitosan particles for drug delivery. J Mater Sci Mater Med. 2009, 20, 917-923.
108.	Qayyum, A. S.; Jain, E.; Kolar, G.; Kim, Y.; Sell, S. A.; Zustiak, S. P. Design of electrohydrodynamic sprayed polyethylene glycol hydrogel microspheres for cell encapsulation. Biofabrication. 2017, 9, 025019.
109.	He, J.; Chen, C.; Chen, L.; Cheng, R.; Sun, J.; Liu, X.; Wang, L.; Zhu, C.; Hu, S.; Xue, Y.; Lu, J.; Yang, H.; Cui, W.; Shi, Q. Honeycomb-like hydrogel microspheres for 3D bulk construction of tumor models. Research (Wash D C). 2022, 2022, 9809763.
110.	Li, X.; Li, X.; Yang, J.; Lin, J.; Zhu, Y.; Xu, X.; Cui, W. Living and injectable porous hydrogel microsphere with paracrine activity for cartilage regeneration. Small. 2023, 19, e2207211.
111.	Ji, X.; Shao, H.; Li, X.; Ullah, M. W.; Luo, G.; Xu, Z.; Ma, L.; He, X.; Lei, Z.; Li, Q.; Jiang, X.; Yang, G.; Zhang, Y. Injectable immunomodulation-based porous chitosan microspheres/HPCH hydrogel composites as a controlled drug delivery system for osteochondral regeneration. Biomaterials. 2022, 285, 121530.
112.	Zeng, H.; Song, J.; Li, Y.; Guo, C.; Zhang, Y.; Yin, T.; He, H.; Gou, J.; Tang, X. Effect of hydroxyethyl starch on drug stability and release of semaglutide in PLGA microspheres. Int J Pharm. 2024, 654, 123991.
113.	Cheng, P.; Cheng, L.; Han, H.; Li, J.; Ma, C.; Huang, H.; Zhou, J.; Feng, J.; Huang, Y.; Lv, Y.; Huang, H.; Wang, Y.; Hou, L.; Chen, Y.; Li, G. A pH/H(2) O(2) /MMP9 time-response gel system with sparc(high) tregs derived extracellular vesicles promote recovery after acute myocardial infarction. Adv Healthc Mater. 2022, 11, e2200971.
114.	Tang, Y.; Du, Y.; Ye, J.; Deng, L.; Cui, W. Intestine-targeted explosive hydrogel microsphere promotes uric acid excretion for gout therapy. Adv Mater. 2024, 36, e2310492.
115.	Li, X.; Wu, X. The microspheres/hydrogels scaffolds based on the proteins, nucleic acids, or polysaccharides composite as carriers for tissue repair: a review. Int J Biol Macromol. 2023, 253, 126611.
116.	Wei, D. X.; Dao, J. W.; Chen, G. Q. A micro-ark for cells: highly open porous polyhydroxyalkanoate microspheres as injectable scaffolds for tissue regeneration. Adv Mater. 2018, 30, e1802273.
117.	Li, W.; Chen, J.; Zhao, S.; Huang, T.; Ying, H.; Trujillo, C.; Molinaro, G.; Zhou, Z.; Jiang, T.; Liu, W.; Li, L.; Bai, Y.; Quan, P.; Ding, Y.; Hirvonen, J.; Yin, G.; Santos, H. A.; Fan, J.; Liu, D. High drug-loaded microspheres enabled by controlled in-droplet precipitation promote functional recovery after spinal cord injury. Nat Commun. 2022, 13, 1262.
118.	Ye, M.; Gao, Y.; Liang, M.; Qiu, W.; Ma, X.; Xu, J.; Hu, J.; Xue, P.; Kang, Y.; Xu, Z. Microenvironment-responsive chemotherapeutic nanogels for enhancing tumor therapy via DNA damage and glutathione consumption. Chin Chem Lett. 2022, 33, 4197-4202.
119.	Zhai, K.; Wang, H.; Ding, Q.; Wu, Z.; Ding, M.; Tao, K.; Yang, B. R.; Xie, X.; Li, C.; Wu, J. High-performance strain sensors based on organohydrogel microsphere film for wearable human-computer interfacing. Adv Sci (Weinh). 2023, 10, e2205632.
120.	Liu, J.; Du, C.; Chen, H.; Huang, W.; Lei, Y. Nano-micron combined hydrogel microspheres: novel answer for minimal invasive biomedical applications. Macromol Rapid Commun. 2024, 45, e2300670.
121.	He, Y.; Sun, M.; Wang, J.; Yang, X.; Lin, C.; Ge, L.; Ying, C.; Xu, K.; Liu, A.; Wu, L. Chondroitin sulfate microspheres anchored with drug-loaded liposomes play a dual antioxidant role in the treatment of osteoarthritis. Acta Biomater. 2022, 151, 512-527.
122.	Lin, J.; Chen, L.; Yang, J.; Li, X.; Wang, J.; Zhu, Y.; Xu, X.; Cui, W. Injectable double positively charged hydrogel microspheres for targeting-penetration-phagocytosis. Small. 2022, 18, e2202156.
123.	Xiang, H.; Zhang, C.; Xiong, Y.; Wang, Y.; Pu, C.; He, J.; Chen, L.; Jiang, K.; Zhao, W.; Yang, H.; Wang, F.; Li, Y. MMP13-responsive hydrogel microspheres for osteoarthritis treatment by precise delivery of celecoxib. Mater Des. 2024, 241, 112966.
124.	Chen, K.; Jiao, Y.; Liu, L.; Huang, M.; He, C.; He, W.; Hou, J.; Yang, M.; Luo, X.; Li, C. Communications between bone marrow macrophages and bone cells in bone remodeling. Front Cell Dev Biol. 2020, 8, 598263.
125.	Ma, S.; Wang, C.; Dong, Y.; Jing, W.; Wei, P.; Peng, C.; Liu, Z.; Zhao, B.; Wang, Y. Microsphere-gel composite system with mesenchymal stem cell recruitment, antibacterial, and immunomodulatory properties promote bone regeneration via sequential release of LL37 and W9 peptides. ACS Appl Mater Interfaces. 2022, 14, 38525-38540.
126.	Parada, N.; Romero-Trujillo, A.; Georges, N.; Alcayaga-Miranda, F. Camouflage strategies for therapeutic exosomes evasion from phagocytosis. J Adv Res. 2021, 31, 61-74.
127.	Yang, Y.; Zheng, W.; Tan, W.; Wu, X.; Dai, Z.; Li, Z.; Yan, Z.; Ji, Y.; Wang, Y.; Su, W.; Zhong, S.; Li, Y.; Sun, Y.; Li, S.; Huang, W. Injectable MMP1-sensitive microspheres with spatiotemporally controlled exosome release promote neovascularized bone healing. Acta Biomater. 2023, 157, 321-336.
128.	Li, J.; Wei, G.; Liu, G.; Du, Y.; Zhang, R.; Wang, A.; Liu, B.; Cui, W.; Jia, P.; Xu, Y. Regulating type H vessel formation and bone metabolism via bone-targeting oral micro/nano-hydrogel microspheres to prevent bone loss. Adv Sci (Weinh). 2023, 10, e2207381.
129.	Zhao, Z.; Li, G.; Ruan, H.; Chen, K.; Cai, Z.; Lu, G.; Li, R.; Deng, L.; Cai, M.; Cui, W. Capturing magnesium ions via microfluidic hydrogel microspheres for promoting cancellous bone regeneration. ACS Nano. 2021, 15, 13041-13054.
130.	Lin, S.; Yin, S.; Shi, J.; Yang, G.; Wen, X.; Zhang, W.; Zhou, M.; Jiang, X. Orchestration of energy metabolism and osteogenesis by Mg(2+) facilitates low-dose BMP-2-driven regeneration. Bioact Mater. 2022, 18, 116-127.
131.	Li, X.; Liu, X.; Ni, S.; Liu, Y.; Sun, H.; Lin, Q. Enhanced osteogenic healing process of rat tooth sockets using a novel simvastatin-loaded injectable microsphere-hydrogel system. J Craniomaxillofac Surg. 2019, 47, 1147-1154.
132.	Xu, X.; Chen, H.; He, P.; Zhao, Z.; Gao, X.; Liu, C.; Cheng, H.; Jiang, L.; Wang, P.; Zhang, Y.; Wen, X.; Li, Y.; Huang, J.; Xiong, Y.; Mao, J.; Ma, H.; Liu, G. 3D hollow porous radio-granular hydrogels for SPECT imaging-guided cancer intravascular brachytherapy. Adv Funct Mater. 2023, 33, 2215110.
133.	Shen, C.; Wang, J.; Li, G.; Hao, S.; Wu, Y.; Song, P.; Han, Y.; Li, M.; Wang, G.; Xu, K.; Zhang, H.; Ren, X.; Jing, Y.; Yang, R.; Geng, Z.; Su, J. Boosting cartilage repair with silk fibroin-DNA hydrogel-based cartilage organoid precursor. Bioact Mater. 2024, 35, 429-444.
134.	Li, Q.; Deng, Y.; Liu, X. Delivering multifunctional peptide-conjugated gene carrier/miRNA-218 complexes from monodisperse microspheres for bone regeneration. ACS Appl Mater Interfaces. 2022, 14, 42904-42914.
135.	Vercellino, I.; Sazanov, L. A. The assembly, regulation and function of the mitochondrial respiratory chain. Nat Rev Mol Cell Biol. 2022, 23, 141-161.
136.	Wang, X.; Lei, Y.; Jiang, K.; Yan, C.; Shen, J.; Zhao, W.; Xiang, C.; Cai, Z.; Song, Y.; Chen, L.; Cui, W.; Li, Y. Mito-battery: Micro-nanohydrogel microspheres for targeted regulation of cellular mitochondrial respiratory chain. Nano Today. 2023, 49, 101820.
137.	Wu, S.; Wang, Z.; Wang, Y.; Guo, M.; Zhou, M.; Wang, L.; Ma, J.; Zhang, P. Peptide-grafted microspheres for mesenchymal stem cell sorting and expansion by selective adhesion. Front Bioeng Biotechnol. 2022, 10, 873125.
138.	Park, W.; Jang, S.; Kim, T. W.; Bae, J.; Oh, T. I.; Lee, E. Microfluidic-printed microcarrier for in vitro expansion of adherent stem cells in 3D culture platform. Macromol Biosci. 2019, 19, e1900136.
139.	Sulaiman, S.; Chowdhury, S. R.; Fauzi, M. B.; Rani, R. A.; Yahaya, N. H. M.; Tabata, Y.; Hiraoka, Y.; Binti Haji Idrus, R.; Min Hwei, N. 3D culture of MSCs on a gelatin microsphere in a dynamic culture system enhances chondrogenesis. Int J Mol Sci. 2020, 21, 2688.
140.	Chen, Z.; Lv, Z.; Zhuang, Y.; Saiding, Q.; Yang, W.; Xiong, W.; Zhang, Z.; Chen, H.; Cui, W.; Zhang, Y. Mechanical signal-tailored hydrogel microspheres recruit and train stem cells for precise differentiation. Adv Mater. 2023, 35, e2300180.
141.	Xu, M.; Liu, T.; Qin, M.; Cheng, Y.; Lan, W.; Niu, X.; Wei, Y.; Hu, Y.; Lian, X.; Zhao, L.; Chen, S.; Chen, W.; Huang, D. Bone-like hydroxyapatite anchored on alginate microspheres for bone regeneration. Carbohydr Polym. 2022, 287, 119330.
142.	Yuan, Z.; Yuan, X.; Zhao, Y.; Cai, Q.; Wang, Y.; Luo, R.; Yu, S.; Wang, Y.; Han, J.; Ge, L.; Huang, J.; Xiong, C. Injectable GelMA cryogel microspheres for modularized cell delivery and potential vascularized bone regeneration. Small. 2021, 17, e2006596.
143.	Zhong, M.; Wei, D.; Yang, Y.; Sun, J.; Chen, X.; Guo, L.; Wei, Q.; Wan, Y.; Fan, H.; Zhang, X. Vascularization in engineered tissue construct by assembly of cellular patterned micromodules and degradable microspheres. ACS Appl Mater Interfaces. 2017, 9, 3524-3534.
144.	Weidenbacher, L.; Abrishamkar, A.; Rottmar, M.; Guex, A. G.; Maniura-Weber, K.; deMello, A. J.; Ferguson, S. J.; Rossi, R. M.; Fortunato, G. Electrospraying of microfluidic encapsulated cells for the fabrication of cell-laden electrospun hybrid tissue constructs. Acta Biomater. 2017, 64, 137-147.
145.	Yang, Y.; Huang, C.; Zheng, H.; Meng, Z.; Heng, B. C.; Zhou, T.; Jiang, S.; Wei, Y. Superwettable and injectable GelMA-MSC microspheres promote cartilage repair in temporomandibular joints. Front Bioeng Biotechnol. 2022, 10, 1026911.
146.	Zhang, R.; Xie, L.; Wu, H.; Yang, T.; Zhang, Q.; Tian, Y.; Liu, Y.; Han, X.; Guo, W.; He, M.; Liu, S.; Tian, W. Alginate/laponite hydrogel microspheres co-encapsulating dental pulp stem cells and VEGF for endodontic regeneration. Acta Biomater. 2020, 113, 305-316.
147.	Wang, H.; Leeuwenburgh, S. C.; Li, Y.; Jansen, J. A. The use of micro- and nanospheres as functional components for bone tissue regeneration. Tissue Eng Part B Rev. 2012, 18, 24-39.
148.	Leite, Á. J.; Caridade, S. G.; Mano, J. F. Synthesis and characterization of bioactive biodegradable chitosan composite spheres with shape memory capability. J Non·Cryst Solids. 2016, 432, 158-166.
149.	Wang, C. C.; Yang, K. C.; Lin, K. H.; Liu, H. C.; Lin, F. H. A highly organized three-dimensional alginate scaffold for cartilage tissue engineering prepared by microfluidic technology. Biomaterials. 2011, 32, 7118-7126.
150.	Han, S.; Yang, H.; Ni, X.; Deng, Y.; Li, Z.; Xing, X.; Du, M. Programmed release of vascular endothelial growth factor and exosome from injectable chitosan nanofibrous microsphere-based PLGA-PEG-PLGA hydrogel for enhanced bone regeneration. Int J Biol Macromol. 2023, 253, 126721.
151.	Davis, H. E.; Binder, B. Y.; Schaecher, P.; Yakoobinsky, D. D.; Bhat, A.; Leach, J. K. Enhancing osteoconductivity of fibrin gels with apatite-coated polymer microspheres. Tissue Eng Part A. 2013, 19, 1773-1782.
152.	Xu, W.; Wei, K.; Lin, Z.; Wu, T.; Li, G.; Wang, L. Storage and release of rare earth elements in microsphere-based scaffolds for enhancing osteogenesis. Sci Rep. 2022, 12, 6383.
153.	Chen, M.; Wang, X.; Ye, Z.; Zhang, Y.; Zhou, Y.; Tan, W. S. A modular approach to the engineering of a centimeter-sized bone tissue construct with human amniotic mesenchymal stem cells-laden microcarriers. Biomaterials. 2011, 32, 7532-7542.
154.	Gupta, V.; Khan, Y.; Berkland, C. J.; Laurencin, C. T.; Detamore, M. S. Microsphere-based scaffolds in regenerative engineering. Annu Rev Biomed Eng. 2017, 19, 135-161.
155.	Shi, X.; Su, K.; Varshney, R. R.; Wang, Y.; Wang, D. A. Sintered microsphere scaffolds for controlled release and tissue engineering. Pharm Res. 2011, 28, 1224-1228.
156.	Luo, X.; Zhang, L.; Luo, Y.; Cai, Z.; Zeng, H.; Wang, T.; Liu, Z.; Chen, Y.; Sheng, X.; Mandlate, A. E. d. G.; Zhou, Z.; Chen, F.; Zheng, L. Charge-driven self-assembled microspheres hydrogel scaffolds for combined drug delivery and photothermal therapy of diabetic wounds. Adv Funct Mater. 2023, 33, 2214036.
157.	Seymour, A. J.; Shin, S.; Heilshorn, S. C. 3D printing of microgel scaffolds with tunable void fraction to promote cell infiltration. Adv Healthc Mater. 2021, 10, e2100644.
158.	Shin, S. H.; Lee, J.; Lim, K. S.; Rhim, T.; Lee, S. K.; Kim, Y. H.; Lee, K. Y. Sequential delivery of TAT-HSP27 and VEGF using microsphere/hydrogel hybrid systems for therapeutic angiogenesis. J Control Release. 2013, 166, 38-45.
159.	Ke, B.; Huang, J.; Duan, Z.; Shen, W.; Wu, Y.; Tu, W.; Fang, X. VEGFA promotes the occurrence of PLA2R-associated idiopathic membranous nephropathy by angiogenesis via the PI3K/AKT signalling pathway. BMC Nephrol. 2022, 23, 313.
160.	Song, S.; Zhang, G.; Chen, X.; Zheng, J.; Liu, X.; Wang, Y.; Chen, Z.; Wang, Y.; Song, Y.; Zhou, Q. HIF-1α increases the osteogenic capacity of ADSCs by coupling angiogenesis and osteogenesis via the HIF-1α/VEGF/AKT/mTOR signaling pathway. J Nanobiotechnology. 2023, 21, 257.
161.	Liao, X. H.; Xiang, Y.; Li, H.; Zheng, L.; Xu, Y.; Xi Yu, C.; Li, J. P.; Zhang, X. Y.; Xing, W. B.; Cao, D. S.; Bao, L. Y.; Zhang, T. C. VEGF-A stimulates STAT3 activity via nitrosylation of myocardin to regulate the expression of vascular smooth muscle cell differentiation markers. Sci Rep. 2017, 7, 2660.
162.	Liu, Q.; Huang, Y.; Lan, Y.; Zuo, Q.; Li, C.; Zhang, Y.; Guo, R.; Xue, W. Acceleration of skin regeneration in full-thickness burns by incorporation of bFGF-loaded alginate microspheres into a CMCS-PVA hydrogel. J Tissue Eng Regen Med. 2017, 11, 1562-1573.
163.	Fu, J.; Fan, C.; Lai, W. S.; Wang, D. Enhancing vascularization of a gelatin-based micro-cavitary hydrogel by increasing the density of the micro-cavities. Biomed Mater. 2016, 11, 055012.
164.	Loi, F.; Córdova, L. A.; Pajarinen, J.; Lin, T. H.; Yao, Z.; Goodman, S. B. Inflammation, fracture and bone repair. Bone. 2016, 86, 119-130.
165.	Zheng, D.; Chen, W.; Chen, T.; Chen, X.; Liang, J.; Chen, H.; Shen, H.; Deng, L.; Ruan, H.; Cui, W. Hydrogen ion capturing hydrogel microspheres for reversing inflammaging. Adv Mater. 2024, 36, e2306105.
166.	Hu, K.; Shang, Z.; Yang, X.; Zhang, Y.; Cao, L. Macrophage polarization and the regulation of bone immunity in bone homeostasis. J Inflamm Res. 2023, 16, 3563-3580.
167.	Sun, J.; Xu, C.; Wo, K.; Wang, Y.; Zhang, J.; Lei, H.; Wang, X.; Shi, Y.; Fan, W.; Zhao, B.; Wang, J.; Su, B.; Yang, C.; Luo, Z.; Chen, L. Wireless electric cues mediate autologous DPSC-loaded conductive hydrogel microspheres to engineer the immuno-angiogenic niche for homologous maxillofacial bone regeneration. Adv Healthc Mater. 2024, 13, e2303405.
168.	Li, D.; Yang, Z.; Zhao, X.; Luo, Y.; Zhou, W.; Xu, J.; Hou, Z.; Kang, P.; Tian, M. Osteoimmunomodulatory injectable Lithium-Heparin hydrogel with Microspheres/TGF-β1 delivery promotes M2 macrophage polarization and osteogenesis for guided bone regeneration. Chem Eng J. 2022, 435, 134991.
169.	Annamalai, R. T.; Turner, P. A.; Carson, W. F. t.; Levi, B.; Kunkel, S.; Stegemann, J. P. Harnessing macrophage-mediated degradation of gelatin microspheres for spatiotemporal control of BMP2 release. Biomaterials. 2018, 161, 216-227.
170.	Li, J.; Xia, T.; Zhao, Q.; Wang, C.; Fu, L.; Zhao, Z.; Tang, Z.; Yin, C.; Wang, M.; Xia, H. Biphasic calcium phosphate recruits Tregs to promote bone regeneration. Acta Biomater. 2024, 176, 432-444.
171.	Shendi, D.; Albrecht, D. R.; Jain, A. Anti-Fas conjugated hyaluronic acid microsphere gels for neural stem cell delivery. J Biomed Mater Res A. 2017, 105, 608-618.
172.	Li, Q.; Zhang, H.; Zeng, Z.; Yan, S.; Hei, Y.; Zhang, Y.; Chen, Y.; Zhang, S.; Zhou, W.; Wei, S.; Sun, Y. Functionalized hydrogel-microsphere composites stimulating neurite outgrowth for vascularized bone regeneration. Biomater Sci. 2023, 11, 5274-5286.
173.	Chen, X.; Ren, L.; Zhang, H.; Hu, Y.; Liao, M.; Shen, Y.; Wang, K.; Cai, J.; Cheng, H.; Guo, J.; Qi, Y.; Wei, H.; Li, X.; Shang, L.; Xiao, J.; Sun, J.; Chai, R. Basic fibroblast growth factor-loaded methacrylate gelatin hydrogel microspheres for spinal nerve regeneration. Smart Med. 2023, 2, e20220038.
174.	Jiang, Y.; Xin, N.; Xiong, Y.; Guo, Y.; Yuan, Y.; Zhang, Q.; Gong, P. αCGRP regulates osteogenic differentiation of bone marrow mesenchymal stem cells through ERK1/2 and p38 MAPK signaling pathways. Cell Transplant. 2022, 31, 9636897221107636.
175.	Liu, S.; Chen, T.; Wang, R.; Huang, H.; Fu, S.; Zhao, Y.; Wang, S.; Wan, L. Exploring the effect of the “quaternary regulation” theory of “peripheral nerve-angiogenesis-osteoclast-osteogenesis” on osteoporosis based on neuropeptides. Front Endocrinol (Lausanne). 2022, 13, 908043.
176.	Hou, P.; Sun, Y.; Yang, W.; Wu, H.; Sun, L.; Xiu, X.; Xiu, C.; Zhang, X.; Zhang, W. Magnesium promotes osteogenesis via increasing OPN expression and activating CaM/CaMKIV/CREB1 pathway. J Biomed Mater Res B Appl Biomater. 2022, 110, 1594-1603.
177.	Hamushan, M.; Cai, W.; Zhang, Y.; Ren, Z.; Du, J.; Zhang, S.; Zhao, C.; Cheng, P.; Zhang, X.; Shen, H.; Han, P. High-purity magnesium pin enhances bone consolidation in distraction osteogenesis via regulating Ptch protein activating Hedgehog-alternative Wnt signaling. Bioact Mater. 2021, 6, 1563-1574.
178.	Liu, J.; Zhou, Z.; Hou, M.; Xia, X.; Liu, Y.; Zhao, Z.; Wu, Y.; Deng, Y.; Zhang, Y.; He, F.; Xu, Y.; Zhu, X. Capturing cerium ions via hydrogel microspheres promotes vascularization for bone regeneration. Mater Today Bio. 2024, 25, 100956.
179.	Mohseni, M.; Shokrollahi, P.; Shokrolahi, F.; Hosseini, S.; Taghiyar, L.; Kamali, A. Dexamethasone loaded injectable, self-healing hydrogel microspheresbased on UPy-functionalized Gelatin/ZnHAp physical network promotes bone regeneration. Int J Pharm. 2022, 626, 122196.
180.	Hanada, K.; Dennis, J. E.; Caplan, A. I. Stimulatory effects of basic fibroblast growth factor and bone morphogenetic protein-2 on osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells. J Bone Miner Res. 1997, 12, 1606-1614.
181.	De Boer, J.; Wang, H. J.; Van Blitterswijk, C. Effects of Wnt signaling on proliferation and differentiation of human mesenchymal stem cells. Tissue Eng. 2004, 10, 393-401.
182.	Jadlowiec, J.; Koch, H.; Zhang, X.; Campbell, P. G.; Seyedain, M.; Sfeir, C. Phosphophoryn regulates the gene expression and differentiation of NIH3T3, MC3T3-E1, and human mesenchymal stem cells via the integrin/MAPK signaling pathway. J Biol Chem. 2004, 279, 53323-53330.
183.	Chen, C. N.; Chang, H. I.; Yen, C. K.; Liu, W. L.; Huang, K. Y. Mechanical stretch induced osteogenesis on human annulus fibrosus cells through upregulation of BMP-2/6 heterodimer and activation of P38 and SMAD1/5/8 signaling pathways. Cells. 2022, 11, 2600.
184.	Kim, H. Y.; Park, S. Y.; Choung, S. Y. Enhancing effects of myricetin on the osteogenic differentiation of human periodontal ligament stem cells via BMP-2/Smad and ERK/JNK/p38 mitogen-activated protein kinase signaling pathway. Eur J Pharmacol. 2018, 834, 84-91.
185.	Pan, S.; Yin, Z.; Shi, C.; Xiu, H.; Wu, G.; Heng, Y.; Zhu, Z.; Zhang, J.; Gui, J.; Yu, Z.; Liang, B. Multifunctional injectable hydrogel microparticles loaded with miR-29a abundant BMSCs derived exosomes enhanced bone regeneration by regulating osteogenesis and angiogenesis. Small. 2024, 20, e2306721.
186.	Lu, G. D.; Cheng, P.; Liu, T.; Wang, Z. BMSC-derived exosomal miR-29a promotes angiogenesis and osteogenesis. Front Cell Dev Biol. 2020, 8, 608521.
187.	Ma, S.; Li, S.; Zhang, Y.; Nie, J.; Cao, J.; Li, A.; Li, Y.; Pei, D. BMSC-derived exosomal CircHIPK3 promotes osteogenic differentiation of MC3T3-E1 cells via mitophagy. Int J Mol Sci. 2023, 24, 2785.
188.	Huang, X.; Das, R.; Patel, A.; Nguyen, T. D. Physical stimulations for bone and cartilage regeneration. Regen Eng Transl Med. 2018, 4, 216-237.
189.	Yang, J.; Liang, J.; Zhu, Y.; Hu, M.; Deng, L.; Cui, W.; Xu, X. Fullerol-hydrogel microfluidic spheres for in situ redox regulation of stem cell fate and refractory bone healing. Bioact Mater. 2021, 6, 4801-4815.
190.	Udit, S.; Blake, K.; Chiu, I. M. Somatosensory and autonomic neuronal regulation of the immune response. Nat Rev Neurosci. 2022, 23, 157-171.
191.	Zhang, Q.; Wu, B.; Yuan, Y.; Zhang, X.; Guo, Y.; Gong, P.; Xiang, L. CGRP-modulated M2 macrophages regulate osteogenesis of MC3T3-E1 via Yap1. Arch Biochem Biophys. 2021, 697, 108697.
192.	Luo, J.; Chen, H.; Wang, G.; Lyu, J.; Liu, Y.; Lin, S.; Zhou, M.; Jiang, X. CGRP-loaded porous microspheres protect BMSCs for alveolar bone regeneration in the periodontitis microenvironment. Adv Healthc Mater. 2023, 12, e2301366.
193.	Hong, J.; Zhu, Z.; Wang, Z.; Li, J.; Liu, Z.; Tan, R.; Hao, Y.; Cheng, G. Annular conductive hydrogel-mediated wireless electrical stimulation for augmenting neurogenesis. Adv Healthc Mater. 2024, 13, e2400624.
194.	Li, C.; Zhang, S.; Yao, Y.; Wang, Y.; Xiao, C.; Yang, B.; Huang, J.; Li, W.; Ning, C.; Zhai, J.; Yu, P.; Wang, Y. Piezoelectric bioactive glasses composite promotes angiogenesis by the synergistic effect of wireless electrical stimulation and active ions. Adv Healthc Mater. 2023, 12, e2300064.
195.	Guo, Q.; Liu, Y.; Sun, R.; Yang, F.; Qiao, P.; Zhang, R.; Song, L.; E, L.; Liu, H. Mechanical stimulation induced osteogenic differentiation of BMSCs through TWIST/E2A/p21 axis. Biosci Rep. 2020, 40, BSR20193876.
196.	Uemura, M.; Maeshige, N.; Yamaguchi, A.; Ma, X.; Matsuda, M.; Nishimura, Y.; Hasunuma, T.; Inoue, T.; Yan, J.; Wang, J.; Kondo, H.; Fujino, H. Electrical stimulation facilitates NADPH production in pentose phosphate pathway and exerts an anti-inflammatory effect in macrophages. Sci Rep. 2023, 13, 17819.
197.	Kang, H.; Zhang, K.; Wong, D. S. H.; Han, F.; Li, B.; Bian, L. Near-infrared light-controlled regulation of intracellular calcium to modulate macrophage polarization. Biomaterials. 2018, 178, 681-696.

[1]	Chung-Hsun Lin, Jesse R. Srioudom, Wei Sun, Malcolm Xing, Su Yan, Le Yu, Jian Yang. The use of hydrogel microspheres as cell and drug delivery carriers for bone, cartilage, and soft tissue regeneration [J]. Biomaterials Translational, 2024, 5(3): 236-256.
[2]	Congyang Xue, Liping Chen, Nan Wang, Heng Chen, Wenqiang Xu, Zhipeng Xi, Qing Sun, Ran Kang, Lin Xie, Xin Liu. Stimuli-responsive hydrogels for bone tissue engineering [J]. Biomaterials Translational, 2024, 5(3): 257-273.
[3]	Shuhao Yang, Haoming Wu, Chao Peng, Jian He, Zhengguang Pu, Zhidong Lin, Jun Wang, Yingkun Hu, Qiao Su, Bingnan Zhou, Xin Yong, Hai Lan, Ning Hu, Xulin Hu. From the microspheres to scaffolds: advances in polymer microsphere scaffolds for bone regeneration applications [J]. Biomaterials Translational, 2024, 5(3): 274-299.
[4]	Haohan Wang, Yonglin Guo, Yiwen Jiang, Yingyu Ge, Hanyi Wang, Dingyi Shi, Guoyang Zhang, Jinzhong Zhao, Yuhao Kang, Liren Wang. Exosome-loaded biomaterials for tendon/ligament repair [J]. Biomaterials Translational, 2024, 5(2): 129-143.
[5]	Jin Yang, Kanwal Fatima, Xiaojun Zhou, Chuanglong He. Meticulously engineered three-dimensional-printed scaffold with microarchitecture and controlled peptide release for enhanced bone regeneration [J]. Biomaterials Translational, 2024, 5(1): 69-83.
[6]	Long Bai, Peiran Song, Jiacan Su. Bioactive elements manipulate bone regeneration [J]. Biomaterials Translational, 2023, 4(4): 248-269.
[7]	Andrew Tai, Euphemie Landao-Bassonga, Ziming Chen, Minh Tran, Brent Allan, Rui Ruan, Dax Calder, Mithran Goonewardene, Hien Ngo, Ming Hao Zheng. Systematic evaluation of three porcine-derived collagen membranes for guided bone regeneration [J]. Biomaterials Translational, 2023, 4(1): 41-50.
[8]	Xirui Jing, Qiuyue Ding, Qinxue Wu, Weijie Su, Keda Yu, Yanlin Su, Bing Ye, Qing Gao, Tingfang Sun, Xiaodong Guo. Magnesium-based materials in orthopaedics: material properties and animal models [J]. Biomaterials Translational, 2021, 2(3): 197-213.
[9]	Jishan Yuan, Panita Maturavongsadit, Zhihui Zhou, Bin Lv, Yuan Lin, Jia Yang, Jittima Amie Luckanagul. Hyaluronic acid-based hydrogels with tobacco mosaic virus containing cell adhesive peptide induce bone repair in normal and osteoporotic rats [J]. Biomaterials Translational, 2020, 1(1): 89-98.

Hydrogel microspheres for bone regeneration through regulation of the regenerative microenvironment

RichHTML

PDF

Knowledge

Abstract

Cite this article

Figures/Tables 11

References 197

Related Articles 9

Recommended Articles

Metrics

Comments

Journal Info

For Authors

For Reviewers

Archives