Background Natural articular cartilage has a limited capacity for spontaneous regeneration. Controlled release of transforming growth factor-β1 （TGF-β1） to cartilage defects can enhance chondrogenesis. In this stu...Background Natural articular cartilage has a limited capacity for spontaneous regeneration. Controlled release of transforming growth factor-β1 （TGF-β1） to cartilage defects can enhance chondrogenesis. In this study, we assessed the feasibility of using biodegradable chitosan microspheres as carriers for controlled TGF-β1 delivery and the effect of released TGF-β1 on the chondrogenic potential of chondrocytes. Methods Chitosan scaffolds and chitosan microspheres loaded with TGF-β1 were prepared by the freeze-drying and the emulsion-crosslinking method respectively. In vitro drug release kinetics, as measured by enzyme-linked immunosorbent assay, was monitored for 7 days. Lysozyme degradation was performed for 4 weeks to detect in vitro degradability of the scaffolds and the microspheres. Rabbit chondrocytes were seeded on the scaffolds containing TGF-β1 microspheres and incubated in vitro for 3 weeks. Histological examination and type Ⅱ collagen immunohistochemical staining was performed to evaluate the effects of released TGF-β1 on cell adhesivity, proliferation and synthesis of the extracellular matrix. Results TGF-β1 was encapsulated into chitosan microspheres and the encapsulation efficiency of TGF-β1 was high （90.1%）. During 4 weeks of incubation in lysozyme solution for in vitro degradation, the mass of both the scaffolds and the microspheres decreased continuously and significant morphological changes was noticed. From the release experiments, it was found that TGF-β1 could be released from the microspheres in a multiphasic fashion including an initial burst phase, a slow linear release phase and a plateau phase. The release amount of TGF-β1 was 37.4%, 50.7%, 61.3%, and 63.5% for 1, 3, 5, and 7 days respectively. At 21 days after cultivation, type II collagen immunohistochemical staining was performed. The mean percentage of positive cells for collagen type II in control group （32.7%± 10.4%） was significantly lower than that in the controlled TGF-β1 release group （92.4%±4.8%, P〈0.05）. Both the proliferation rate and production of collagen type Ⅱ in the transforming growth factor-β1 microsphere incorporated scaffolds were significantly higher than those in the scaffolds without microspheres, indicating that the activity of TGF-β1 was retained during microsphere fabrication and after growth factor release. Conclusion Chitosan microspheres can serve as delivery vehicles for controlled release of TGF-β1, and the released growth factor can augment chondrocytes proliferation and synthesis of extracellular matrix. Chitosan scaffolds incorporated with chitosan microspheres loaded with TGF-β1 possess a promising potential to be applied for controlled cytokine delivery and cartilage tissue engineering.展开更多
Porous titanium with porosity of 60% was prepared by metal injection molding（MIM）,and coated with gelatin sustained-release microspheres which were made by improved emulsified cold condensation method.The effects of...Porous titanium with porosity of 60% was prepared by metal injection molding（MIM）,and coated with gelatin sustained-release microspheres which were made by improved emulsified cold condensation method.The effects of porous titanium coated with insulin-like growth factor-1（IGF-1） and transforming growth factor-β1（TGF-β1） gelatin microspheres on the function of MG63 cells were evaluated in vitro.The results show that porous titanium coated with gelatin sustained-release microspheres has no cytotoxicity.The IGF-1 and TGF-β1 loading concentrations are positively correlative with the proliferation and differentiation of MG63 after co-culturing with the concentrations of IGF-1 and TGF-β1 gelatin microspheres in the range of 0.1-10 ng/mg and 0.25-2.5 ng/mg,respectively.The MG63 cells exhibit the best proliferation and differentiation with the IGF-1 and TGF-β1 loading concentrations of 10 ng/mg and 2.5 ng/mg,respectively.The joint application of IGF-1 and TGF-β1 group,which promote adhesion,proliferation and differentiation of MG63 cells,is superior to a single application group.展开更多
Intervertebral disc degeneration(IVDD)is one of the main causes of low back pain.Although local delivery strategies using biomaterial carriers have shown potential for IVDD treatment,it remains challenging for interve...Intervertebral disc degeneration(IVDD)is one of the main causes of low back pain.Although local delivery strategies using biomaterial carriers have shown potential for IVDD treatment,it remains challenging for intervention against multiple adverse contributors by a single delivery platform.In the present work,we propose a new functionalization strategy using vanillin,a natural molecule with anti-inflammatory and antioxidant properties,to develop multifunctional gelatin methacrylate(GelMA)microspheres for local delivery of transforming growth factorβ3(TGFβ3)toward IVDD treatment.In vitro,functionalized microspheres not only improved the release kinetics of TGFβ3 but also effectively inhibited inflammatory responses and promoted the secretion of extracellular matrix(ECM)in lipopolysaccharide-induced nucleus pulposus(NP)cells.In vivo,functionalized platform plays roles in alleviating inflammation and oxidative stress,preserving the water content of NP and disc height,and maintaining intact structure and biomechanical functions,thereby promoting the regeneration of IVD.High-throughput sequencing suggests that inhibition of the phosphatidylinositol 3-kinase(PI3K)-Akt signaling might be associated with their therapeutic effects.In summary,the vanillin-based functionalization strategy provides a novel and simple way for packaging multiple functions into a single delivery platform and holds promise for tissue regeneration beyond the IVD.展开更多
基金the National Natural Science Foundation of China (No. 30000056)the Science and Technology Project Foundation of Guangdong Province (No.2003A302102).
文摘Background Natural articular cartilage has a limited capacity for spontaneous regeneration. Controlled release of transforming growth factor-β1 （TGF-β1） to cartilage defects can enhance chondrogenesis. In this study, we assessed the feasibility of using biodegradable chitosan microspheres as carriers for controlled TGF-β1 delivery and the effect of released TGF-β1 on the chondrogenic potential of chondrocytes. Methods Chitosan scaffolds and chitosan microspheres loaded with TGF-β1 were prepared by the freeze-drying and the emulsion-crosslinking method respectively. In vitro drug release kinetics, as measured by enzyme-linked immunosorbent assay, was monitored for 7 days. Lysozyme degradation was performed for 4 weeks to detect in vitro degradability of the scaffolds and the microspheres. Rabbit chondrocytes were seeded on the scaffolds containing TGF-β1 microspheres and incubated in vitro for 3 weeks. Histological examination and type Ⅱ collagen immunohistochemical staining was performed to evaluate the effects of released TGF-β1 on cell adhesivity, proliferation and synthesis of the extracellular matrix. Results TGF-β1 was encapsulated into chitosan microspheres and the encapsulation efficiency of TGF-β1 was high （90.1%）. During 4 weeks of incubation in lysozyme solution for in vitro degradation, the mass of both the scaffolds and the microspheres decreased continuously and significant morphological changes was noticed. From the release experiments, it was found that TGF-β1 could be released from the microspheres in a multiphasic fashion including an initial burst phase, a slow linear release phase and a plateau phase. The release amount of TGF-β1 was 37.4%, 50.7%, 61.3%, and 63.5% for 1, 3, 5, and 7 days respectively. At 21 days after cultivation, type II collagen immunohistochemical staining was performed. The mean percentage of positive cells for collagen type II in control group （32.7%± 10.4%） was significantly lower than that in the controlled TGF-β1 release group （92.4%±4.8%, P〈0.05）. Both the proliferation rate and production of collagen type Ⅱ in the transforming growth factor-β1 microsphere incorporated scaffolds were significantly higher than those in the scaffolds without microspheres, indicating that the activity of TGF-β1 was retained during microsphere fabrication and after growth factor release. Conclusion Chitosan microspheres can serve as delivery vehicles for controlled release of TGF-β1, and the released growth factor can augment chondrocytes proliferation and synthesis of extracellular matrix. Chitosan scaffolds incorporated with chitosan microspheres loaded with TGF-β1 possess a promising potential to be applied for controlled cytokine delivery and cartilage tissue engineering.
基金Project(2013zzts306)supported by the Fundamental Research Funds for the Central Universities of Central South University,ChinaProject(225)supported by the High Level Health Personnel in Hunan Province,China
文摘Porous titanium with porosity of 60% was prepared by metal injection molding（MIM）,and coated with gelatin sustained-release microspheres which were made by improved emulsified cold condensation method.The effects of porous titanium coated with insulin-like growth factor-1（IGF-1） and transforming growth factor-β1（TGF-β1） gelatin microspheres on the function of MG63 cells were evaluated in vitro.The results show that porous titanium coated with gelatin sustained-release microspheres has no cytotoxicity.The IGF-1 and TGF-β1 loading concentrations are positively correlative with the proliferation and differentiation of MG63 after co-culturing with the concentrations of IGF-1 and TGF-β1 gelatin microspheres in the range of 0.1-10 ng/mg and 0.25-2.5 ng/mg,respectively.The MG63 cells exhibit the best proliferation and differentiation with the IGF-1 and TGF-β1 loading concentrations of 10 ng/mg and 2.5 ng/mg,respectively.The joint application of IGF-1 and TGF-β1 group,which promote adhesion,proliferation and differentiation of MG63 cells,is superior to a single application group.
基金supported by National Natural Science Foundation of China(81925027,32130059,81871805 and 82072424)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutionsthe Key Laboratory of Orthopaedics of Suzhou(SZS2022017).
文摘Intervertebral disc degeneration(IVDD)is one of the main causes of low back pain.Although local delivery strategies using biomaterial carriers have shown potential for IVDD treatment,it remains challenging for intervention against multiple adverse contributors by a single delivery platform.In the present work,we propose a new functionalization strategy using vanillin,a natural molecule with anti-inflammatory and antioxidant properties,to develop multifunctional gelatin methacrylate(GelMA)microspheres for local delivery of transforming growth factorβ3(TGFβ3)toward IVDD treatment.In vitro,functionalized microspheres not only improved the release kinetics of TGFβ3 but also effectively inhibited inflammatory responses and promoted the secretion of extracellular matrix(ECM)in lipopolysaccharide-induced nucleus pulposus(NP)cells.In vivo,functionalized platform plays roles in alleviating inflammation and oxidative stress,preserving the water content of NP and disc height,and maintaining intact structure and biomechanical functions,thereby promoting the regeneration of IVD.High-throughput sequencing suggests that inhibition of the phosphatidylinositol 3-kinase(PI3K)-Akt signaling might be associated with their therapeutic effects.In summary,the vanillin-based functionalization strategy provides a novel and simple way for packaging multiple functions into a single delivery platform and holds promise for tissue regeneration beyond the IVD.
