A new biomimetic bone tissue engineering scaffold material, nano-HAI PLGA-（ PEG-Asp ）n composite, was synthesized by a biologically inspired self-assembling approach. A novel biodegradable PLGA- （ PEG-Asp ）n cop...A new biomimetic bone tissue engineering scaffold material, nano-HAI PLGA-（ PEG-Asp ）n composite, was synthesized by a biologically inspired self-assembling approach. A novel biodegradable PLGA- （ PEG-Asp ）n copolymer with pendant amine functional groups and enhanced hydrophilicity woo synthesized by bulk ring-opening copolymerization by DL-lactide（ DLLA） and glycolide（ GA ） with Aspartic acid （ Asp ）-Polyethylene glycol（PEG） alt-prepolymer. A Three-dimensional, porous scaffold of the PLGA-（ PEG- Asp）n copolymer was fabricated by a solvent casting , particulate leaching process. The scaffold woo then incubated in modified simulated body fluid （naSBF）. Growth of HA nanocrystals on the inner pore surfaces of the porous scaffold is confirmed by calcium ion binding analyses, SEM , mass increooe meoourements and quantification of phosphate content within scaffolds. SEM analysis demonstrated the nucleation and growth of a continuous bonelike, low crystalline carbonated HA nanocrystals on the inner pore surfaces of the PLGA- （ PEG-Asp ）n scaffolds. The amount of calcium binding, total mass and the mass of phosphate on experimental PLGA- （ PEG-Asp ） n scaffolds at different incubation times in mSBF was significantly greater than that of control PLGA scaffolds. This nano-HA/ PLGA-（ PEG- Asp ）n composite stunts some features of natural bone both in main composition and hierarchical microstrueture. The Asp- PEG alt-prepolymer modified PleA copolymer provide a controllable high surface density and distribution of anionic functional groups which would enhance nucleation and growth of bonelike mineral following exposure to mSBF. This biomimetic treatment provides a simple method for surface functionalization and sabsequent mineral nucleation and self-oosembling on bodegradable polymer scaffolds for tissue engineering.展开更多
Development of suitable materials that acts as an interface between the implant and tissues in body system structurally, mechanically and bio functionally is important for the success of tissue engineering. This motiv...Development of suitable materials that acts as an interface between the implant and tissues in body system structurally, mechanically and bio functionally is important for the success of tissue engineering. This motivated materials scientists and biologists to find out suitable bioactive materials for the aforementioned purpose. There has been growing interest in developing bioactive synthetic ceramics that could closely mimic natural apatite characteristics. Hydroxyapatite (HAp) has been widely used as a biocompatible ceramic but mainly for contact with bone tissue, due to its resemblance to mineral bone. This study presents the synthesis and characterization of HAp materials from different sources like bovine bone and fish scales and their application in tissue engineering. The phase purity and crystallinity of different calcined HAp powder was determined by XRD and FTIR analysis. The Thermo Gravimetric and Differential Thermal Analysis were carried out to show the thermal stability of the HAp powder. The morphology of the powder was observed under Scanning Electron Microscopy (SEM). Cytotoxicity evaluation of the developed powder was carried out in RAW macrophage like cell line media for an incubation period of 72 hours. These results proved the biocompatibility of HAp powders obtained from different biosources for tissue engineering applications.展开更多
With the excellent biocompatibility and osteo- conductivity, nano-hydroxyapatite （nHA） has shown significant prospect in the biomedical applications. Con- trolling the size, crystallinity and surface properties of n...With the excellent biocompatibility and osteo- conductivity, nano-hydroxyapatite （nHA） has shown significant prospect in the biomedical applications. Con- trolling the size, crystallinity and surface properties of nHA crystals is a critical challenge in the design of HA based biomaterials. With the graft copolymer of chitosan and poly（N-isopropylacrylamide） in coil and globule states as a template respectively, a novel composite from chitosan-g-poly（N-isopropylacrylamide） and nano-hydro- xyapatite （CS-g-PNIPAM/nHA） was prepared via co- precipitation. Zeta potential analysis, thermogravimetric analysis and X-ray diffraction were used to identify the formation mechanism of the CS-g-PNIPAM/nHA compo- site and its morphology was observed by transmission electron microscopy. The results suggested that the physical aggregation states of the template polymer could induce or control the size, crystallinity and morphology of HA crystals in the CS-g-PNIPAM/nHA composite. The CS-g-PNIPAM/nHA composite was then introduced to chitosan-gelatin （CS-Gel） polyelectronic complex and the cytocompatibility of the resulting CS- Gel/composite hybrid film was evaluated. This hybrid film was proved to be favorable for the proliferation of MC 3T3-E1 cells. Therefore, the CS-g-PNIPAM/nHA compo- site is a potential biomaterial in bone tissue engineering.展开更多
A micro-envioment for nerve cells and tissue growth were designed and constructed via surface modification of poly（L-lactide-co-glycolide）（PLGA） with chitosan and hydroxyapatire（HA）. The poly（L_lactide-co-glyco...A micro-envioment for nerve cells and tissue growth were designed and constructed via surface modification of poly（L-lactide-co-glycolide）（PLGA） with chitosan and hydroxyapatire（HA）. The poly（L_lactide-co-glycolide）/chitosan/hydroxyapatite （PLGA/chitosan/HA） conduits were manufactured by a combined solvent casting and particulate leaching technique. The conduits were highly porous with an interconnected pore structure and 76.5% porosity. Micropores with 50-100 micrometer diameter were formed in the conduits. In vivo application of PLGA/chitosan/HA conduits for reconstruction of 10 mm sciatic nerve defect was assessed by the walking track analysis, the quantifying of the wet weight of tibialis anterior muscle and the histological assessment. The conduits in host rats in vivo can not only be an effective in promoting regenerating of nerves but can also lead to favorable nerve functional recovery.展开更多
With the pursuit of new cancer therapies and more effective treatment to diseases in the last decades, nanotechnology has been an important ally for healthcare professionals and patients in critical clinical condition...With the pursuit of new cancer therapies and more effective treatment to diseases in the last decades, nanotechnology has been an important ally for healthcare professionals and patients in critical clinical conditions. Nanomaterials offer an alternative way to deliver toxic chemotherapeutic drugs to specific biological tissues, specific cells or specific microbial beings, resulting in avoidance of strong side effects or resilience to effective drugs. Among these materials, stands out the hydroxyapatite nanoparticles, a ceramic class of calcium phosphates that present chemical and structural similarities with the mineral phase of the human skeleton’s bone matrix, resulting in important biological features, such as biocompatibility, osteoconductive, osteoinduction and osteoaffinity, which led to a lot of scientific researches to apply these nanoparticles for bone diseases diagnosis and therapeutics. Due to the hydroxyapatite biological activities and due to the possibility to promote chemical and physical modifications in these nanoparticles, they can interact with biological cells or microorganisms in different ways, resulting in multiple potentialities to be explored such as apoptosis induction to cancerous cells, osteogenesis promotion, cellular proliferation, angiogenesis and tissue recovery, in addition to promote cell adhesion and cell uptake. Furthermore, chemical and physical modifications, such as surface functionalization, dopant inclusions and radiolabeling process, allow scientists to track the particle activities in biological environments. In the last decades of scientific productions, the literature brings together important data on how hydroxyapatite nanoparticles interact with biological tissues and such data are crucial for the development of more effective therapeutic and diagnostic agents. In the present review, we intend to compile scholarly information to explore the biological relations of nanosized hydroxyapatite with the human cellular environment and the feasible modifications that may improve the theragnostic efficacy of these molecules.展开更多
The biodegradation rate and biocompatibility of poly(d, / -lactide) (PDLLA) in vivo were evaluated. The aim of this study was to establish a nerve guide constructed by the PDLLA with 3-D microenvironment and to repair...The biodegradation rate and biocompatibility of poly(d, / -lactide) (PDLLA) in vivo were evaluated. The aim of this study was to establish a nerve guide constructed by the PDLLA with 3-D microenvironment and to repair a 10 mm of sciatic nerve gap in rats. The process of the nerve regeneration was investigated by histological assessment, electrophysiological examination, and determination of wet weight recovery rate of the gastrocnemius muscle. After 3 weeks, the nerve guide had changed from a transparent to an opaque status. The conduit was degraded and absorbed partly and had lost their strength with breakage at the 9th week of postoperation. At the conclusion of 12 weeks, proximal and distal end of nerves were anastomosed by nerve regeneration and the conduit vanished completely. The results suggest that PDLLA conduits may serve for peripheral nerve regeneration and PDLLA is a sort of hopeful candidate for tissue engineering.展开更多
背景:羟基磷灰石是骨组织的主要无机成分,聚合物可仿生细胞外基质的结构和功能,两者的复合材料得到了广泛研究。目的:总结羟基磷灰石复合聚合物材料用于骨组织修复的研究现状。方法:检索2010年1月至2023年4月PubMed、Web of Science、...背景:羟基磷灰石是骨组织的主要无机成分,聚合物可仿生细胞外基质的结构和功能,两者的复合材料得到了广泛研究。目的:总结羟基磷灰石复合聚合物材料用于骨组织修复的研究现状。方法:检索2010年1月至2023年4月PubMed、Web of Science、中国知网及万方数据库收录的相关文献,中文检索词为“羟基磷灰石,聚合物,复合材料,可降解性,骨缺损,骨修复”,英文检索词:“hydroxyapatite,polymer,composites,degradability,bone defect,bone repair”,最终纳入75篇文献进行综述分析。结果与结论:常与羟基磷灰石复合用于骨组织修复的聚合物包括天然聚合物(胶原、壳聚糖、海藻酸盐、丝素蛋白、纤维素、透明质酸、聚羟基丁酸酯等)和合成聚合物(聚乳酸、聚乳酸-羟基乙酸共聚物、聚己内酯、聚氨基酸、聚乙烯醇等)。羟基磷灰石/聚合物复合材料较纯羟基磷灰石的机械性能、骨诱导性得到了提高,羟基磷灰石与聚合物复合可制成多孔支架、水凝胶、涂层等用于骨修复。羟基磷灰石/聚合物复合材料因其仿生细胞外基质结构和功能可缓释负载的药物和细胞因子,加速骨重建。基于骨缺损原因的多样性以及骨修复为多种生物因子和蛋白共同参与的复杂连续过程,机械性能与骨组织匹配、降解过程与骨修复同步、高效成骨成血管的修复材料有待进一步研究。展开更多
文摘A new biomimetic bone tissue engineering scaffold material, nano-HAI PLGA-（ PEG-Asp ）n composite, was synthesized by a biologically inspired self-assembling approach. A novel biodegradable PLGA- （ PEG-Asp ）n copolymer with pendant amine functional groups and enhanced hydrophilicity woo synthesized by bulk ring-opening copolymerization by DL-lactide（ DLLA） and glycolide（ GA ） with Aspartic acid （ Asp ）-Polyethylene glycol（PEG） alt-prepolymer. A Three-dimensional, porous scaffold of the PLGA-（ PEG- Asp）n copolymer was fabricated by a solvent casting , particulate leaching process. The scaffold woo then incubated in modified simulated body fluid （naSBF）. Growth of HA nanocrystals on the inner pore surfaces of the porous scaffold is confirmed by calcium ion binding analyses, SEM , mass increooe meoourements and quantification of phosphate content within scaffolds. SEM analysis demonstrated the nucleation and growth of a continuous bonelike, low crystalline carbonated HA nanocrystals on the inner pore surfaces of the PLGA- （ PEG-Asp ）n scaffolds. The amount of calcium binding, total mass and the mass of phosphate on experimental PLGA- （ PEG-Asp ） n scaffolds at different incubation times in mSBF was significantly greater than that of control PLGA scaffolds. This nano-HA/ PLGA-（ PEG- Asp ）n composite stunts some features of natural bone both in main composition and hierarchical microstrueture. The Asp- PEG alt-prepolymer modified PleA copolymer provide a controllable high surface density and distribution of anionic functional groups which would enhance nucleation and growth of bonelike mineral following exposure to mSBF. This biomimetic treatment provides a simple method for surface functionalization and sabsequent mineral nucleation and self-oosembling on bodegradable polymer scaffolds for tissue engineering.
文摘Development of suitable materials that acts as an interface between the implant and tissues in body system structurally, mechanically and bio functionally is important for the success of tissue engineering. This motivated materials scientists and biologists to find out suitable bioactive materials for the aforementioned purpose. There has been growing interest in developing bioactive synthetic ceramics that could closely mimic natural apatite characteristics. Hydroxyapatite (HAp) has been widely used as a biocompatible ceramic but mainly for contact with bone tissue, due to its resemblance to mineral bone. This study presents the synthesis and characterization of HAp materials from different sources like bovine bone and fish scales and their application in tissue engineering. The phase purity and crystallinity of different calcined HAp powder was determined by XRD and FTIR analysis. The Thermo Gravimetric and Differential Thermal Analysis were carried out to show the thermal stability of the HAp powder. The morphology of the powder was observed under Scanning Electron Microscopy (SEM). Cytotoxicity evaluation of the developed powder was carried out in RAW macrophage like cell line media for an incubation period of 72 hours. These results proved the biocompatibility of HAp powders obtained from different biosources for tissue engineering applications.
文摘With the excellent biocompatibility and osteo- conductivity, nano-hydroxyapatite （nHA） has shown significant prospect in the biomedical applications. Con- trolling the size, crystallinity and surface properties of nHA crystals is a critical challenge in the design of HA based biomaterials. With the graft copolymer of chitosan and poly（N-isopropylacrylamide） in coil and globule states as a template respectively, a novel composite from chitosan-g-poly（N-isopropylacrylamide） and nano-hydro- xyapatite （CS-g-PNIPAM/nHA） was prepared via co- precipitation. Zeta potential analysis, thermogravimetric analysis and X-ray diffraction were used to identify the formation mechanism of the CS-g-PNIPAM/nHA compo- site and its morphology was observed by transmission electron microscopy. The results suggested that the physical aggregation states of the template polymer could induce or control the size, crystallinity and morphology of HA crystals in the CS-g-PNIPAM/nHA composite. The CS-g-PNIPAM/nHA composite was then introduced to chitosan-gelatin （CS-Gel） polyelectronic complex and the cytocompatibility of the resulting CS- Gel/composite hybrid film was evaluated. This hybrid film was proved to be favorable for the proliferation of MC 3T3-E1 cells. Therefore, the CS-g-PNIPAM/nHA compo- site is a potential biomaterial in bone tissue engineering.
基金Funded by the National Natural Science Foundation of China(No.50774096)
文摘A micro-envioment for nerve cells and tissue growth were designed and constructed via surface modification of poly（L-lactide-co-glycolide）（PLGA） with chitosan and hydroxyapatire（HA）. The poly（L_lactide-co-glycolide）/chitosan/hydroxyapatite （PLGA/chitosan/HA） conduits were manufactured by a combined solvent casting and particulate leaching technique. The conduits were highly porous with an interconnected pore structure and 76.5% porosity. Micropores with 50-100 micrometer diameter were formed in the conduits. In vivo application of PLGA/chitosan/HA conduits for reconstruction of 10 mm sciatic nerve defect was assessed by the walking track analysis, the quantifying of the wet weight of tibialis anterior muscle and the histological assessment. The conduits in host rats in vivo can not only be an effective in promoting regenerating of nerves but can also lead to favorable nerve functional recovery.
文摘With the pursuit of new cancer therapies and more effective treatment to diseases in the last decades, nanotechnology has been an important ally for healthcare professionals and patients in critical clinical conditions. Nanomaterials offer an alternative way to deliver toxic chemotherapeutic drugs to specific biological tissues, specific cells or specific microbial beings, resulting in avoidance of strong side effects or resilience to effective drugs. Among these materials, stands out the hydroxyapatite nanoparticles, a ceramic class of calcium phosphates that present chemical and structural similarities with the mineral phase of the human skeleton’s bone matrix, resulting in important biological features, such as biocompatibility, osteoconductive, osteoinduction and osteoaffinity, which led to a lot of scientific researches to apply these nanoparticles for bone diseases diagnosis and therapeutics. Due to the hydroxyapatite biological activities and due to the possibility to promote chemical and physical modifications in these nanoparticles, they can interact with biological cells or microorganisms in different ways, resulting in multiple potentialities to be explored such as apoptosis induction to cancerous cells, osteogenesis promotion, cellular proliferation, angiogenesis and tissue recovery, in addition to promote cell adhesion and cell uptake. Furthermore, chemical and physical modifications, such as surface functionalization, dopant inclusions and radiolabeling process, allow scientists to track the particle activities in biological environments. In the last decades of scientific productions, the literature brings together important data on how hydroxyapatite nanoparticles interact with biological tissues and such data are crucial for the development of more effective therapeutic and diagnostic agents. In the present review, we intend to compile scholarly information to explore the biological relations of nanosized hydroxyapatite with the human cellular environment and the feasible modifications that may improve the theragnostic efficacy of these molecules.
基金Acknowledgements This work was supported by the High Technology Research and Development Program (Grant No. 863-715-002-0210) and the National Basic Science Research and Development Grants (Grant No. 973, G1999054306).
文摘The biodegradation rate and biocompatibility of poly(d, / -lactide) (PDLLA) in vivo were evaluated. The aim of this study was to establish a nerve guide constructed by the PDLLA with 3-D microenvironment and to repair a 10 mm of sciatic nerve gap in rats. The process of the nerve regeneration was investigated by histological assessment, electrophysiological examination, and determination of wet weight recovery rate of the gastrocnemius muscle. After 3 weeks, the nerve guide had changed from a transparent to an opaque status. The conduit was degraded and absorbed partly and had lost their strength with breakage at the 9th week of postoperation. At the conclusion of 12 weeks, proximal and distal end of nerves were anastomosed by nerve regeneration and the conduit vanished completely. The results suggest that PDLLA conduits may serve for peripheral nerve regeneration and PDLLA is a sort of hopeful candidate for tissue engineering.
文摘背景:羟基磷灰石是骨组织的主要无机成分,聚合物可仿生细胞外基质的结构和功能,两者的复合材料得到了广泛研究。目的:总结羟基磷灰石复合聚合物材料用于骨组织修复的研究现状。方法:检索2010年1月至2023年4月PubMed、Web of Science、中国知网及万方数据库收录的相关文献,中文检索词为“羟基磷灰石,聚合物,复合材料,可降解性,骨缺损,骨修复”,英文检索词:“hydroxyapatite,polymer,composites,degradability,bone defect,bone repair”,最终纳入75篇文献进行综述分析。结果与结论:常与羟基磷灰石复合用于骨组织修复的聚合物包括天然聚合物(胶原、壳聚糖、海藻酸盐、丝素蛋白、纤维素、透明质酸、聚羟基丁酸酯等)和合成聚合物(聚乳酸、聚乳酸-羟基乙酸共聚物、聚己内酯、聚氨基酸、聚乙烯醇等)。羟基磷灰石/聚合物复合材料较纯羟基磷灰石的机械性能、骨诱导性得到了提高,羟基磷灰石与聚合物复合可制成多孔支架、水凝胶、涂层等用于骨修复。羟基磷灰石/聚合物复合材料因其仿生细胞外基质结构和功能可缓释负载的药物和细胞因子,加速骨重建。基于骨缺损原因的多样性以及骨修复为多种生物因子和蛋白共同参与的复杂连续过程,机械性能与骨组织匹配、降解过程与骨修复同步、高效成骨成血管的修复材料有待进一步研究。
