A PVA- GAG- COL composite scaffold is fabricated by polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL). Laser surface modification technology is used to make holes on the surface of the scaffolds. Ins...A PVA- GAG- COL composite scaffold is fabricated by polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL). Laser surface modification technology is used to make holes on the surface of the scaffolds. Inside and outside interconnection microporous structure is obtained. Biocompatibility test of the scaffolds shows that PVA- GAG- COL scaffold can promote the adhesion and proliferation of the fibroblast. Also, fibroblast can grow normally on the scaffolds with pore diameter from 115 um to 255 um and pore distance from 500 um to 2000 um. PVA- GAG- COL scaffolds possess excellent cell biocompatibility. The porous structure is suitable for cell culture in tissue engineering.展开更多
With the development of tissue engineering,the required biomaterials need to have the ability to promote cell adhesion and proliferation in vitro and in vivo.Especially,surface modification of the scaffold material ha...With the development of tissue engineering,the required biomaterials need to have the ability to promote cell adhesion and proliferation in vitro and in vivo.Especially,surface modification of the scaffold material has a great influence on biocompatibility and functionality of materials.The small intestine submucosa(SIS)is an extracellular matrix isolated from the submucosal layer of porcine jejunum,which has good tissue mechanical properties and regenerative activity,and is suitable for cell adhesion,proliferation and differentiation.In recent years,SIS is widely used in different areas of tissue reconstruction,such as blood vessels,bone,cartilage,bladder and ureter,etc.This paper discusses the main methods for surface modification of SIS to improve and optimize the performance of SIS bioscaffolds,including functional group bonding,protein adsorption,mineral coating,topography and formatting modification and drug combination.In addition,the reasonable combination of these methods also offers great improvement on SIS surface modification.This article makes a shallow review of the surface modification of SIS and its application in tissue engineering.展开更多
Developing bioactive biomaterials with highly controlled functions is crucial to enhancing their applications in regenerative medicine.Citrate-based polymers are the few bioactive polymer biomaterials used in biomedic...Developing bioactive biomaterials with highly controlled functions is crucial to enhancing their applications in regenerative medicine.Citrate-based polymers are the few bioactive polymer biomaterials used in biomedicine because of their facile synthesis,controllable structure,biocompatibility,biomimetic viscoelastic mechanical behavior,and functional groups available for modification.In recent years,various multifunctional designs and biomedical applications,including cardiovascular,orthopedic,muscle tissue,skin tissue,nerve and spinal cord,bioimaging,and drug or gene delivery based on citrate-based polymers,have been extensively studied,and many of them have good clinical application potential.In this review,we summarize recent progress in the multifunctional design and biomedical applications of citrate-based polymers.We also discuss the further development of multifunctional citrate-based polymers with tailored properties to meet the requirements of various biomedical applications.展开更多
Textile-based technologies are considered as potential routes for the production of 3D porous architectures for tissue engineering( TE) applications. We describe the use of two polymers,namely polybutylene succinate( ...Textile-based technologies are considered as potential routes for the production of 3D porous architectures for tissue engineering( TE) applications. We describe the use of two polymers,namely polybutylene succinate( PBS) and silk fibroin(SF) to produce fiber-based finely tuned porous architectures by weft and warp knittings. The obtained knitted constructs are described in terms of their morphology, mechanical properties,swelling ability,degradation behaviour,and cytotoxicity. Each type of polymer fibers allows for the processing of a very reproducible intra-architectural scaffold geometry,with distinct characteristics in terms of the surface physicochemistry,mechanical performance,and degradation capability,which has an impact on the resulting cell behaviour at the surface of the respective biotextiles. Preliminary cytotoxicity screening shows that both materials can support cell adhesion and proliferation. Furthermore, different surface modifications were performed( acid /alkaline treatment, UV radiation,and plasma) for modulating cell behavior. An increase of cell-material interactions were observed,indicating the important role of materials surface in the first hours of culturing. Human adipose-derived stem cells( hASCs) became an emerging possibility for regenerative medicine and tissue replacement therapies. The potential of the recently developed silk-based biotextile structures to promote hASCs adhesion,proliferation,and differentiation is also evaluated. The obtained results validate the developed constructs as viable matrices for TE applications. Given the processing efficacy and versatility of the knitting technology, and the interesting structural and surface properties of the proposed polymer fibers,it is foreseen that our developed systems can be attractive for the functional engineering of tissues such as bone,skin,ligaments or cartilage and also for develop more complex systems for further industrialization of TE products.展开更多
Magnesium and its alloys are one of the most used materials for bone implants and tissue engineering.They are characterized by numerous advantages such as biodegradability,high biocompatibility and mechanical properti...Magnesium and its alloys are one of the most used materials for bone implants and tissue engineering.They are characterized by numerous advantages such as biodegradability,high biocompatibility and mechanical properties with values close to the human bone.Unfortunately,the implant surface must be adequately tuned,or Mg-based alloys must be alloyed with other chemical elements due to their increased corrosion effect in physiological media.This article reviews the clinical challenges related to bone repair and regeneration,classifying bone defects and presenting some of the most used and modern therapies for bone injuries,such as Ilizarov or Masquelet techniques or stem cell treatments.The implant interface challenges are related to new bone formation and fracture healing,implant degradation and hydrogen release.A detailed analysis of mechanical properties during implant degradation is extensively described based on different literature studies that included in vitro and in vivo tests correlated with material properties’characterization.Mg-based trauma implants such as plates and screws,intramedullary nails,Herbert screws,spine cages,rings for joint treatment and regenerative scaffolds are presented,taking into consideration their manufacturing technology,the implant geometrical dimensions and shape,the type of in vivo or in vitro studies and fracture localization.Modern technologies that modify or adapt the Mg-based implant interfaces are described by presenting the main surface microstructural modifications,physical deposition and chemical conversion coatings.The last part of the article provides some recommendations from a translational perspective,identifies the challenges associated with Mg-based implants and presents some future opportunities.This review outlines the available literature on trauma and regenerative bone implants and describes the main techniques used to control the alloy corrosion rate and the cellular environment of the implant.展开更多
背景:股骨头坏死出现新月征是病情进程的“分水岭”,修复和稳定骨-软骨界面对阻止病情继续进展和预防股骨头塌陷尤为重要。利用组织工程学同步修复、整合骨-软骨界面具有潜在优势。目的:综述探讨解决股骨头坏死软骨下分离的潜在适宜技...背景:股骨头坏死出现新月征是病情进程的“分水岭”,修复和稳定骨-软骨界面对阻止病情继续进展和预防股骨头塌陷尤为重要。利用组织工程学同步修复、整合骨-软骨界面具有潜在优势。目的:综述探讨解决股骨头坏死软骨下分离的潜在适宜技术。方法:检索1970年1月至2023年4月PubMed、Web of Science及中国知网、万方数据库中发表的相关文献,英文检索词:“Femoral head necrosis,Avascular necrosis of femoral head,Osteonecrosis of femoral head”等,中文检索词:“股骨头坏死,软骨下骨,软骨,软骨与软骨下骨整合”等,最终纳入114篇文献进行综述分析。结果与结论:①结构缺陷、缺血缺氧环境、炎症因素和应力集中可能造成股骨头坏死软骨下分离现象,软骨下骨分离会造成塌陷进展,并且可能与保髋手术失败相关,利用组织工程支架实现支架与骨-软骨界面的整合是治疗股骨头坏死软骨下分离的潜在方法之一。②目前的文献研究表明,多相、梯度支架和复合材料在促进骨、软骨细胞黏附与增殖,骨软骨基质的沉积方面均有提升,有助于支架与骨-软骨界面的整合,对治疗股骨头坏死软骨下分离有参考价值。③通过对支架表面进行修饰可以提高与界面整合的效率,但有各自不同的优缺点,提供不同环境的支架能够诱导同种间充质干细胞差异分化,有助于不同界面之间的整合。④未来有望应用于股骨头坏死软骨下分离的支架应为复合材料,具有梯度化和差异化的仿生结构,通过表面修饰和干细胞加载促进骨-软骨界面与支架的整合以实现治疗目的,但仍需进一步研究验证,而支架的降解速率与修复进度同步和不同界面之间的稳定性是未来需要解决的主要问题。展开更多
背景:对于支架物理性质的研究始终是组织工程研究领域的热点,但对于促血管支架来说,除了要满足支架的基本性能外,还需要通过其他方法来促进血管在支架内的再生过程,以达到修复骨组织的最终目的。目的:对国内外发表的骨组织工程下促血管...背景:对于支架物理性质的研究始终是组织工程研究领域的热点,但对于促血管支架来说,除了要满足支架的基本性能外,还需要通过其他方法来促进血管在支架内的再生过程,以达到修复骨组织的最终目的。目的:对国内外发表的骨组织工程下促血管支架的文献进行可视化分析,探究该领域的研究热点及研究现状,为后续研究提供参考。方法:以中国知网及Web of Science核心集数据库为检索库,检索骨组织工程下促血管支架的相关文献,去除不符合纳入标准的文献,随后导入CiteSpace 6.1.R2软件,对研究领域的作者、国家机构及关键词进行可视化分析。结果与结论:①骨组织工程下促血管支架应用的研究中,发文量最多的前3个国家分别为中国、美国和德国。②中国知网数据库机构该领域研究发文量排名前3位分别为南方医科大学、华中科技大学、东华大学;Web of Science核心集数据库中机构发文量排名前3位分别为上海交通大学、四川大学、中国科学院。③中国知网数据库关键词频次排名前3位为“组织工程、血管化、血管生成”,Web of Science核心集数据库关键词频次排名前3位为“mesenchymal stem cell(间充质干细胞),scaffold(支架),vascularization(血管化)”。④参考文献共被引情况和高被引文献分析显示,该领域的血管化策略研究热点为支架设计、血管生成因子的输送、体外共培养和体内预血管化;技术方面研究热点为3D打印、静电纺丝、血管移植及血管融合;机制方面研究热点为免疫调节和巨噬细胞、药物/生长因子输送、内皮细胞和成骨细胞之间的关系、骨细胞和内皮细胞之间旁分泌关系及信号分子通路、血管生成和抗血管生成分子。⑤国内外骨组织工程下促血管支架应用研究均十分重视干细胞和3D打印技术的运用,而目前的研究热点主要为生物3D打印技术、支架改性修饰的方法以及基于骨修复机制智能生物材料的开发应用。展开更多
The introduction of neurotrophic factors into injured peripheral nerve sites is beneficial to peripheral nerve regeneration.However,neurotrophic facto rs are rapidly degraded in vivo and obstruct axonal regeneration w...The introduction of neurotrophic factors into injured peripheral nerve sites is beneficial to peripheral nerve regeneration.However,neurotrophic facto rs are rapidly degraded in vivo and obstruct axonal regeneration when used at a supraphysiological dose,which limits their clinical benefits.Bioactive mimetic peptides have been developed to be used in place of neurotrophic factors because they have a similar mode of action to the original growth fa ctors and can activate the equivalent receptors but have simplified sequences and structures.In this study,we created polydopamine-modified chitin conduits loaded with brain-derived neurotrophic factor mimetic peptides and vascular endothelial growth fa ctor mimetic peptides(Chi/PDA-Ps).We found that the Chi/PDA-Ps conduits were less cytotoxic in vitro than chitin conduits alone and provided sustained release of functional peptides.In this study,we evaluated the biocompatibility of the Chi/P DA-Ps conduits.Brain-derived neurotrophic factor mimetic peptide and vascular endothelial growth fa ctor mimetic peptide synergistically promoted prolife ration of Schwann cells and secretion of neurotrophic factors by Schwann cells and attachment and migration of endothelial cells in vitro.The Chi/P DA-Ps conduits were used to bridge a 2 mm gap between the nerve stumps in rat models of sciatic nerve injury.We found that the application of Chi/PDA-Ps conduits could improve the motor function of rats and reduce gastrocnemius atrophy.The electrophysiological results and the microstructure of regenerative nerves showed that the nerve conduction function and re myelination was further resto red.These findings suggest that the Chi/PDA-Ps conduits have great potential in peripheral nerve injury repair.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
基金863 Program grant number: 2077AA09Z436+1 种基金Guangdong Province '211' Fund for Biomaterials and Tissue Engineering grantnumber: 50621030
文摘A PVA- GAG- COL composite scaffold is fabricated by polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL). Laser surface modification technology is used to make holes on the surface of the scaffolds. Inside and outside interconnection microporous structure is obtained. Biocompatibility test of the scaffolds shows that PVA- GAG- COL scaffold can promote the adhesion and proliferation of the fibroblast. Also, fibroblast can grow normally on the scaffolds with pore diameter from 115 um to 255 um and pore distance from 500 um to 2000 um. PVA- GAG- COL scaffolds possess excellent cell biocompatibility. The porous structure is suitable for cell culture in tissue engineering.
基金supported by the National Natural Science Foundation of China(No.81571919)LiaoNing Revitalization Talents Program(No.XLYC1907124).
文摘With the development of tissue engineering,the required biomaterials need to have the ability to promote cell adhesion and proliferation in vitro and in vivo.Especially,surface modification of the scaffold material has a great influence on biocompatibility and functionality of materials.The small intestine submucosa(SIS)is an extracellular matrix isolated from the submucosal layer of porcine jejunum,which has good tissue mechanical properties and regenerative activity,and is suitable for cell adhesion,proliferation and differentiation.In recent years,SIS is widely used in different areas of tissue reconstruction,such as blood vessels,bone,cartilage,bladder and ureter,etc.This paper discusses the main methods for surface modification of SIS to improve and optimize the performance of SIS bioscaffolds,including functional group bonding,protein adsorption,mineral coating,topography and formatting modification and drug combination.In addition,the reasonable combination of these methods also offers great improvement on SIS surface modification.This article makes a shallow review of the surface modification of SIS and its application in tissue engineering.
基金supported by the National Natural Science Foundation of China(grant No.52172288)Special Support Program for High Level Talents of Shaanxi Province of China(grant No.TZ0278)+4 种基金the key R&D plan of Shaanxi Province of China(grant No.2021GXLH-Z-052)State Key Laboratory for Manufacturing Systems Engineering of China(grant No.sklms2021006)Young Talent Support Plan of Xi’an Jiaotong University of China(grant No.QY6J003)the Fundamental Research Funds for the Central Universities(grant No.xzy012021075)China Postdoctoral Science Foundation(grant No.2021M702644).
文摘Developing bioactive biomaterials with highly controlled functions is crucial to enhancing their applications in regenerative medicine.Citrate-based polymers are the few bioactive polymer biomaterials used in biomedicine because of their facile synthesis,controllable structure,biocompatibility,biomimetic viscoelastic mechanical behavior,and functional groups available for modification.In recent years,various multifunctional designs and biomedical applications,including cardiovascular,orthopedic,muscle tissue,skin tissue,nerve and spinal cord,bioimaging,and drug or gene delivery based on citrate-based polymers,have been extensively studied,and many of them have good clinical application potential.In this review,we summarize recent progress in the multifunctional design and biomedical applications of citrate-based polymers.We also discuss the further development of multifunctional citrate-based polymers with tailored properties to meet the requirements of various biomedical applications.
文摘Textile-based technologies are considered as potential routes for the production of 3D porous architectures for tissue engineering( TE) applications. We describe the use of two polymers,namely polybutylene succinate( PBS) and silk fibroin(SF) to produce fiber-based finely tuned porous architectures by weft and warp knittings. The obtained knitted constructs are described in terms of their morphology, mechanical properties,swelling ability,degradation behaviour,and cytotoxicity. Each type of polymer fibers allows for the processing of a very reproducible intra-architectural scaffold geometry,with distinct characteristics in terms of the surface physicochemistry,mechanical performance,and degradation capability,which has an impact on the resulting cell behaviour at the surface of the respective biotextiles. Preliminary cytotoxicity screening shows that both materials can support cell adhesion and proliferation. Furthermore, different surface modifications were performed( acid /alkaline treatment, UV radiation,and plasma) for modulating cell behavior. An increase of cell-material interactions were observed,indicating the important role of materials surface in the first hours of culturing. Human adipose-derived stem cells( hASCs) became an emerging possibility for regenerative medicine and tissue replacement therapies. The potential of the recently developed silk-based biotextile structures to promote hASCs adhesion,proliferation,and differentiation is also evaluated. The obtained results validate the developed constructs as viable matrices for TE applications. Given the processing efficacy and versatility of the knitting technology, and the interesting structural and surface properties of the proposed polymer fibers,it is foreseen that our developed systems can be attractive for the functional engineering of tissues such as bone,skin,ligaments or cartilage and also for develop more complex systems for further industrialization of TE products.
基金supported by a grant of the Romanian Ministry of Education and Research,CNCS-UEFISCDI,project number PN-III-P4-ID-PCE-2020-2591,within PNCDI III。
文摘Magnesium and its alloys are one of the most used materials for bone implants and tissue engineering.They are characterized by numerous advantages such as biodegradability,high biocompatibility and mechanical properties with values close to the human bone.Unfortunately,the implant surface must be adequately tuned,or Mg-based alloys must be alloyed with other chemical elements due to their increased corrosion effect in physiological media.This article reviews the clinical challenges related to bone repair and regeneration,classifying bone defects and presenting some of the most used and modern therapies for bone injuries,such as Ilizarov or Masquelet techniques or stem cell treatments.The implant interface challenges are related to new bone formation and fracture healing,implant degradation and hydrogen release.A detailed analysis of mechanical properties during implant degradation is extensively described based on different literature studies that included in vitro and in vivo tests correlated with material properties’characterization.Mg-based trauma implants such as plates and screws,intramedullary nails,Herbert screws,spine cages,rings for joint treatment and regenerative scaffolds are presented,taking into consideration their manufacturing technology,the implant geometrical dimensions and shape,the type of in vivo or in vitro studies and fracture localization.Modern technologies that modify or adapt the Mg-based implant interfaces are described by presenting the main surface microstructural modifications,physical deposition and chemical conversion coatings.The last part of the article provides some recommendations from a translational perspective,identifies the challenges associated with Mg-based implants and presents some future opportunities.This review outlines the available literature on trauma and regenerative bone implants and describes the main techniques used to control the alloy corrosion rate and the cellular environment of the implant.
文摘背景:股骨头坏死出现新月征是病情进程的“分水岭”,修复和稳定骨-软骨界面对阻止病情继续进展和预防股骨头塌陷尤为重要。利用组织工程学同步修复、整合骨-软骨界面具有潜在优势。目的:综述探讨解决股骨头坏死软骨下分离的潜在适宜技术。方法:检索1970年1月至2023年4月PubMed、Web of Science及中国知网、万方数据库中发表的相关文献,英文检索词:“Femoral head necrosis,Avascular necrosis of femoral head,Osteonecrosis of femoral head”等,中文检索词:“股骨头坏死,软骨下骨,软骨,软骨与软骨下骨整合”等,最终纳入114篇文献进行综述分析。结果与结论:①结构缺陷、缺血缺氧环境、炎症因素和应力集中可能造成股骨头坏死软骨下分离现象,软骨下骨分离会造成塌陷进展,并且可能与保髋手术失败相关,利用组织工程支架实现支架与骨-软骨界面的整合是治疗股骨头坏死软骨下分离的潜在方法之一。②目前的文献研究表明,多相、梯度支架和复合材料在促进骨、软骨细胞黏附与增殖,骨软骨基质的沉积方面均有提升,有助于支架与骨-软骨界面的整合,对治疗股骨头坏死软骨下分离有参考价值。③通过对支架表面进行修饰可以提高与界面整合的效率,但有各自不同的优缺点,提供不同环境的支架能够诱导同种间充质干细胞差异分化,有助于不同界面之间的整合。④未来有望应用于股骨头坏死软骨下分离的支架应为复合材料,具有梯度化和差异化的仿生结构,通过表面修饰和干细胞加载促进骨-软骨界面与支架的整合以实现治疗目的,但仍需进一步研究验证,而支架的降解速率与修复进度同步和不同界面之间的稳定性是未来需要解决的主要问题。
文摘背景:对于支架物理性质的研究始终是组织工程研究领域的热点,但对于促血管支架来说,除了要满足支架的基本性能外,还需要通过其他方法来促进血管在支架内的再生过程,以达到修复骨组织的最终目的。目的:对国内外发表的骨组织工程下促血管支架的文献进行可视化分析,探究该领域的研究热点及研究现状,为后续研究提供参考。方法:以中国知网及Web of Science核心集数据库为检索库,检索骨组织工程下促血管支架的相关文献,去除不符合纳入标准的文献,随后导入CiteSpace 6.1.R2软件,对研究领域的作者、国家机构及关键词进行可视化分析。结果与结论:①骨组织工程下促血管支架应用的研究中,发文量最多的前3个国家分别为中国、美国和德国。②中国知网数据库机构该领域研究发文量排名前3位分别为南方医科大学、华中科技大学、东华大学;Web of Science核心集数据库中机构发文量排名前3位分别为上海交通大学、四川大学、中国科学院。③中国知网数据库关键词频次排名前3位为“组织工程、血管化、血管生成”,Web of Science核心集数据库关键词频次排名前3位为“mesenchymal stem cell(间充质干细胞),scaffold(支架),vascularization(血管化)”。④参考文献共被引情况和高被引文献分析显示,该领域的血管化策略研究热点为支架设计、血管生成因子的输送、体外共培养和体内预血管化;技术方面研究热点为3D打印、静电纺丝、血管移植及血管融合;机制方面研究热点为免疫调节和巨噬细胞、药物/生长因子输送、内皮细胞和成骨细胞之间的关系、骨细胞和内皮细胞之间旁分泌关系及信号分子通路、血管生成和抗血管生成分子。⑤国内外骨组织工程下促血管支架应用研究均十分重视干细胞和3D打印技术的运用,而目前的研究热点主要为生物3D打印技术、支架改性修饰的方法以及基于骨修复机制智能生物材料的开发应用。
基金the National Natural Science Foundation of China,Nos.31771322,31571235the Natural Science Foundation of Beijing,No.7212121+3 种基金Beijing Science Technology New Star Cross Subject of China,No.2018019Shenzhen Science and Technology Plan Project of China,No.JCYJ 20190806162205278the Key Laboratory of Trauma and Neural Regeneration(Peking University),Ministry of Educationa grant from National Center for Trauma Medicine,No.BMU2020XY005-01(all to PXZ)。
文摘The introduction of neurotrophic factors into injured peripheral nerve sites is beneficial to peripheral nerve regeneration.However,neurotrophic facto rs are rapidly degraded in vivo and obstruct axonal regeneration when used at a supraphysiological dose,which limits their clinical benefits.Bioactive mimetic peptides have been developed to be used in place of neurotrophic factors because they have a similar mode of action to the original growth fa ctors and can activate the equivalent receptors but have simplified sequences and structures.In this study,we created polydopamine-modified chitin conduits loaded with brain-derived neurotrophic factor mimetic peptides and vascular endothelial growth fa ctor mimetic peptides(Chi/PDA-Ps).We found that the Chi/PDA-Ps conduits were less cytotoxic in vitro than chitin conduits alone and provided sustained release of functional peptides.In this study,we evaluated the biocompatibility of the Chi/P DA-Ps conduits.Brain-derived neurotrophic factor mimetic peptide and vascular endothelial growth fa ctor mimetic peptide synergistically promoted prolife ration of Schwann cells and secretion of neurotrophic factors by Schwann cells and attachment and migration of endothelial cells in vitro.The Chi/P DA-Ps conduits were used to bridge a 2 mm gap between the nerve stumps in rat models of sciatic nerve injury.We found that the application of Chi/PDA-Ps conduits could improve the motor function of rats and reduce gastrocnemius atrophy.The electrophysiological results and the microstructure of regenerative nerves showed that the nerve conduction function and re myelination was further resto red.These findings suggest that the Chi/PDA-Ps conduits have great potential in peripheral nerve injury repair.
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.