골조직공학을 위한 바이오나노마이크로 입자가 결합된 다기능 하이드로겔 개발 = System Integrated Bio-Nano/Micro Particles in Hydrogel Network Structure as Versatile Biomaterials for Bone Tissue Engineering

다국어 초록 (Multilingual Abstract)

Bone defects and injuries remain critical clinical challenges, often compounded by infection, impaired healing, and the inherent limitations of conventional grafts and implants. The urgent need for advanced biomaterials that can simultaneously provide structural support, promote biological function, and prevent microbial colonization motivates the present research. The primary purpose of this dissertation is to develop and systematically evaluate multifunctional hydrogel scaffolds that integrate mechanical reinforcement, bioactivity, and antimicrobial functionality, thereby addressing key limitations of conventional materials and advancing strategies for effective bone tissue regeneration.
Hydrogels serve as versatile platforms for tissue engineering, evolving from simple single-network systems to more sophisticated double-network and microbead architectures. Single-network hydrogels offer fundamental structural support, whereas double-network hydrogels improve mechanical strength and porosity. Microbead formulations further enable minimally invasive delivery, spatial targeting, and enhanced functional responsiveness, broadening their potential for complex regenerative applications. Integrating nanoparticles into these hydrogels enhances their functional capabilities, enabling bioactivity, antimicrobial protection, and improved cell-material interactions.
In this work, natural polysaccharides such as chitosan and sodium alginate were selected as primary hydrogel matrices due to their biocompatibility, crosslinking potential, and structural versatility. Copper-doped mesoporous silica nanospheres and zinc oxide nanoparticles were incorporated to provide synergistic osteoinductive and antimicrobial effects, while mineral-coated magnetic nanoparticles enhanced bioactivity and enabled targeted delivery. Poly(ethylene glycol) diacrylate was employed as a complementary network component to reinforce mechanical integrity without dominating the hydrogel architecture. The resulting platforms, spanning bulk double-network hydrogels to injectable microbead systems, demonstrated high cytocompatibility, promoted cell proliferation, enhanced osteogenic differentiation, facilitated matrix mineralization, and exhibited significant antibacterial activity. These outcomes collectively validate the multifunctional performance of the designed hydrogels and demonstrate their potential to overcome the shortcomings of conventional scaffold materials.
By integrating polymer network engineering with bioactive and functional nanoparticles, this dissertation establishes a coherent framework for the design of multifunctional hydrogel scaffolds. The primary objective, to create materials that simultaneously achieve mechanical reinforcement, biological stimulation, and antimicrobial protection, is realized across both bulk and microbead systems. These findings provide a versatile foundation for future development of clinically adaptable scaffolds capable of addressing both sterile and infection-prone bone defects, contributing broadly to the advancement of biomaterials for regenerative medicine.

목차 (Table of Contents)

• List of Figures vii
• List of Tables xix
• List of Abbreviations xx
• Abstract x
• Chapter 1 Introduction 1
• 1.1. Orthopedic/Bone 1
• 1.1.1. Bone Fracture 2
• 1.1.2. Bone Disease 8
• 1.1.3. Bone Cancer 13
• 1.2. Tissue Engineering 17
• 1.2.1. Biomaterial 21
• 1.2.2. Hydrogel 28
• 1.2.3. Chitosan 30
• 1.2.4. Sodium Alginate 33
• 1.2.5. PEGDA 35
• 1.2.6. Extracellular matrix (ECM) 39
• 1.3. Bio-Nano/Micro Particle 41
• 1.4. Nanoparticle 43
• 1.4.1. Calcium Phosphate 46
• 1.4.2. Copper 48
• 1.4.3. Silica 50
• 1.4.4. Magnetic nanoparticles 53
• 1.5. Composite Scaffold 54
• 1.6. Polydopamine 56
• Chapter 2 Cu-MSNs and ZnO nanoparticles incorporated poly(ethylene glycol) diacrylate/sodium alginate double network hydrogel for simultaneous enhancement of osteogenic differentiation 60
• 2.1. Introduction 60
• 2.2. Materials and methods 63
• 2.2.1. Materials 63
• 2.2.2. Synthesis of copper-doped mesoporous silica nanospheres (Cu-MSNs) 63
• 2.2.3. Preparation of hydrogels loaded with ZnO/Cu-MSNs 64
• 2.2.4. Characterization 66
• 2.2.5. Mechanical properties 66
• 2.2.6. Water Absorption, swelling, and degradation 67
• 2.2.7. Porosity and density 68
• 2.2.8. In vitro evaluation of antibacterial property 69
• 2.2.9. In vitro cell culture, cytotoxic, and proliferation 70
• 2.2.10. Morphological study & Osteogenic differentiation 71
• 2.3. Results and discussion 73
• 2.3.1. Synthesis and characterization of Cu-MSNs and ZnO NPs 73
• 2.3.2. Preparation and characterization of PS@ZnO/Cu-MSNs composite hydrogels 78
• 2.3.3. Mechanical properties of ZnO & Cu-MSNs loaded hydrogel 84
• 2.3.4. Antibacterial assay of ZnO & Cu-MSNs loaded hydrogel 87
• 2.3.5. Biocompatibility of composite hydrogels 91
• 2.3.6. Mineralization and osteogenic differentiation 93
• 2.4. Conclusion 98
• Chapter 3 Construction of a PEGDA/Chitosan Hydrogel Incorporating Mineralized Copper-Doped Mesoporous Nanospheres for Accelerated Bone Regeneration 99
• 3.1. Introduction 99
• 3.2. Materials and methods 102
• 3.2.1. Materials 102
• 3.2.2. Synthesis of copper-doped mesoporous silica nanospheres (Cu-MSNs) 102
• 3.2.3. Synthesis of Cu-MSNs/PDA@CaP 103
• 3.2.4. Preparation of hydrogels loaded with m-MSNs 104
• 3.2.5. Characterization 105
• 3.2.6. Mechanical properties 107
• 3.2.7. Water Absorption, swelling, and degradation 107
• 3.2.8. Ion release 108
• 3.2.9. In vitro cell culture, cytotoxicity and proliferation 109
• 3.2.10. Alkaline phosphate (ALP) & Alizarin Red-S (ARS) assay 110
• 3.2.11. Quantification of type I collagen protein 111
• 3.2.12. Osteogenic gene expression 112
• 3.3. Results and discussion 113
• 3.3.1. Fabrication and characterization of m-MSNs and composite hydrogels 113
• 3.3.2. Chemical structure characterization 125
• 3.3.3. Water absorption, swelling ratios, and degradation 128
• 3.3.4. Mechanical property of m-MSNs reinforced P/CS Gels 132
• 3.3.5. Ion release profiles 134
• 3.3.6. Cell proliferation and morphology of MC3T3-E1 cells on the composite hydrogels 137
• 3.3.7. ALP, ARS, and Collagen assay 145
• 3.3.8. Expression of osteogenic-associated genes in MC3T3-E1 cells 152
• 3.4. Conclusion 154
• Chapter 4 Magnetically Responsive Micro-Clustered Calcium Phosphate-Reinforced Cell-Laden Microbead Sodium Alginate Hydrogel for Accelerated Osteogenic Tissue Regeneration 155
• 4.1. Introduction 155
• 4.2. Materials & Methods 159
• 4.2.1. Materials 159
• 4.2.2. Synthesis of superparamagnetic iron oxide nanoparticles (SPIONs) 159
• 4.2.3. Synthesis of Sp/Pda@CaP (m-Sp) 160
• 4.2.4. Fabrication of microbead hydrogels loaded m-Sp 161
• 4.2.5. Fabrication of microbead hydrogels loaded MC3T3-E1 cells 162
• 4.2.6. Characterization 162
• 4.2.7. Water Absorption, swelling, and degradation 163
• 4.2.8. Rheological assessment 164
• 4.2.9. In vitro antibacterial assessment 164
• 4.2.10. Cytocompatibility of composite particles and microbead hydrogels 165
• 4.2.11. Bioactivity 166
• 4.2.12. Alkaline phosphate (ALP) assay & Alizarin Red-S (ARS) 167
• 4.2.13. Quantification of type I collagen protein 168
• 4.2.14. Immunocytochemistry (ICC) 168
• 4.2.15. Microbeads magnetic fixation and targeting simulation 169
• 4.3. Results and Discussion 170
• 4.3.1. Morphology and physicochemical properties of m-Sp 170
• 4.3.2. Synthesis of microbead hydrogels 178
• 4.3.3. Biodegradation of microbead hydrogels 188
• 4.3.4. Antibacterial properties of microbead hydrogels 188
• 4.3.5. In vitro bioactivity of microbead hydrogels 191
• 4.3.6. In vitro biocompatibility and osteogenic assessment of particles 193
• 4.3.7. In vitro biocompatibility and osteogenic assessment of microbead hydrogels 196
• 4.3.8. In vitro migration assay 200
• 4.3.9. Immunocytochemistry Analysis of Microbead Extraction and Cell Encapsulation 202
• 4.4. Conclusion 206
• Chapter 5 Superparamagnetic Mesoporous Silica Nanoparticle-Infused Microbead Hydrogels for Osteomyelitis Diagnosis and Therapy 207
• 5.1. Introduction 207
• 5.2 Materials & Methods 211
• 5.2.1. Materials 211
• 5.2.2. Synthesis of Sp@MSNs 211
• 5.2.3. Preparation of Sodium Alginate-Based Microbeads 212
• 5.2.4. Characterization 213
• 5.2.5. Water Absorption and Swelling Behavior 214
• 5.2.6. Biodegradation Analysis 215
• 5.2.7. Antibacterial Evaluation 215
• 5.2.8. In Vitro Cell Culture and Proliferation Assessment 216
• 5.2.9. Alkaline Phosphate (ALP) Assay 218
• 5.2.10. Alizarin Red-S (ARS) Staining 219
• 5.2.11. Scratch Assay 219
• 5.2.12. Statistical Analysis 220
• 5.3. Results and Discussion 221
• 5.3.1. Structural and spectroscopic characterization of Sp@MSNs 221
• 5.3.2. Synthesis and Characterization of Microbead Hydrogels 225
• 5.3.3 In Vitro Biocompatibility of Nanoparticles 230
• 5.3.4. Antibacterial Assessment 236
• 5.3.5. In Vitro Biocompatibility of Microbead Hydrogels 238
• 5.3.6. In Vitro Scratch Assay 243
• 5.4. Conclusion 245
• Chapter 6 Conclusion 246
• List of Publications 249
• References 252
• 국 문 초 록 282