Dexamethasone-Loaded PLGA Microspheres Incorporated PLLA/PLGA/PCL Composite Scaffold for Bone Tissue Engineering

The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/PCL)composite scaffold with porous structure was fabricated by thermally induced phase separation(TIPS).Dexamethasone(DEX)was incorporated into PLGA microspheres and then loaded on the PLLA/PLGA/PCL scaffoldtopreparethedesiredcompositescaffold.The physicochemical properties of the prepared composite scaffold were characterized.The morphology of rat bone marrow mesenchymal stem cells(BMSCs)grown on scaffolds was observed using scanning electron microscope(SEM)and fluorescence microscope.The resultsshowedthatthePLLA/PLGA/PCLscaffoldhad interconnected macropores and biomimetic nanofibrous structure.In addition,DEX can be released from scaffold in a sustained manner.More importantly,DEX loaded composite scaffold can effectively support the proliferation of BMSCs as indicated by fluorescence observation and cell proliferation assay.The results suggested that the prepared PLLA/PLGA/PCL composite scaffold incorporating drug-loaded PLGA microspheres could hold great potential for bone tissue engineering applications.

Biomaterials and tissue engineering in traumatic brain injury:novel perspectives on promoting neural regeneration

Traumatic brain injury is a serious medical condition that can be attributed to falls, motor vehicle accidents, sports injuries and acts of violence, causing a series of neural injuries and neuropsychiatric symptoms. However, limited accessibility to the injury sites, complicated histological and anatomical structure, intricate cellular and extracellular milieu, lack of regenerative capacity in the native cells, vast variety of damage routes, and the insufficient time available for treatment have restricted the widespread application of several therapeutic methods in cases of central nervous system injury. Tissue engineering and regenerative medicine have emerged as innovative approaches in the field of nerve regeneration. By combining biomaterials, stem cells, and growth factors, these approaches have provided a platform for developing effective treatments for neural injuries, which can offer the potential to restore neural function, improve patient outcomes, and reduce the need for drugs and invasive surgical procedures. Biomaterials have shown advantages in promoting neural development, inhibiting glial scar formation, and providing a suitable biomimetic neural microenvironment, which makes their application promising in the field of neural regeneration. For instance, bioactive scaffolds loaded with stem cells can provide a biocompatible and biodegradable milieu. Furthermore, stem cells-derived exosomes combine the advantages of stem cells, avoid the risk of immune rejection, cooperate with biomaterials to enhance their biological functions, and exert stable functions, thereby inducing angiogenesis and neural regeneration in patients with traumatic brain injury and promoting the recovery of brain function. Unfortunately, biomaterials have shown positive effects in the laboratory, but when similar materials are used in clinical studies of human central nervous system regeneration, their efficacy is unsatisfactory. Here, we review the characteristics and properties of various bioactive materials, followed by the introduction of applications based on biochemistry and cell molecules, and discuss the emerging role of biomaterials in promoting neural regeneration. Further, we summarize the adaptive biomaterials infused with exosomes produced from stem cells and stem cells themselves for the treatment of traumatic brain injury. Finally, we present the main limitations of biomaterials for the treatment of traumatic brain injury and offer insights into their future potential.

Nano-apatite/Polymer Biocomposite for Tissue Engineering

A new kind of tissue engineering scaffold materials of nano-apatite （ NA ） and polyamide6 （ PA6 ） biocomposite was prepared by means of the co-solution method. The NA crystals uniforndy distribute in the composite with a size of 10-30 nm in diameter by 50-90 nm in length. The NA/ PA6 composite has good homogeneity and high NA content, and excellent mechanical properties close to those of natural bone. The porous 3-D scaffold has not only macropores, but also micropores on the walls of macropores with porosity of about 80% and the size of pore diameter of about 300μm made by injection foam. The biocomposite can be used for bone repair and as scaffolds in tissue engineering.

Pores Created by Laser Surface Modification of Poly(vinylalcohol)-Collagen with Glycosaminoglycan Scaffold for Cell Culture in Tissue Engineering

A PVA-GAG-COL composite scaffold is fabricated by polyvinyl alcohol （PVA）, glyeosaminoglycan （GAG） and collagen （COL）. Laser surface modification technology is used to make holes on the surface of the scaffolds. Inside and outside interconnection micro-porous structure is obtained. Bioeompatibility 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.

3D printing of tissue engineering scaffolds:a focus on vascular regeneration

Tissue engineering is an emerging means for resolving the problems of tissue repair and organ replacement in regenerative medicine.Insufficient supply of nutrients and oxygen to cells in large-scale tissues has led to the demand to prepare blood vessels.Scaffold-based tissue engineering approaches are effective methods to form new blood vessel tissues.The demand for blood vessels prompts systematic research on fabrication strategies of vascular scaffolds for tissue engineering.Recent advances in 3D printing have facilitated fabrication of vascular scaffolds,contributing to broad prospects for tissue vascularization.This review presents state of the art on modeling methods,print materials and preparation processes for fabrication of vascular scaffolds,and discusses the advantages and application fields of each method.Specially,significance and importance of scaffold-based tissue engineering for vascular regeneration are emphasized.Print materials and preparation processes are discussed in detail.And a focus is placed on preparation processes based on 3D printing technologies and traditional manufacturing technologies including casting,electrospinning,and Lego-like construction.And related studies are exemplified.Transformation of vascular scaffolds to clinical application is discussed.Also,four trends of 3D printing of tissue engineering vascular scaffolds are presented,including machine learning,near-infrared photopolymerization,4D printing,and combination of self-assembly and 3D printing-based methods.

Effect of PGA/PLA scaffold material on tissue engineering cartilage reconstruction of knee osteoarthritis

Objective:To investigate the effect of PGA/PLA scaffolds on tissue engineering cartilage reconstruction in knee osteoarthritis. Methods:Thirty Japanese white rabbits were divided into three groups. The first group was healthy (group H):normal Japanese white rabbits, without knee osteoarthritis;the second group, knee osteoarthritis group ( Group k):Normal Japanese white rabbits were diagnosed with knee osteoarthritis by model preparation;Group 3, tissue engineering group (Group T):Tissue engineering cartilage reconstruction of Japanese knee white rabbits with knee osteoarthritis. 10 white rabbits per group. The cartilage histological score, HE staining, immunohistochemistry, Western blot, qRT-PCR analysis of H group, k group, T group cartilage histological score, cartilage histopathology and morphological changes, cartilage tissue The difference in Col-Ⅱ protein content and Col-Ⅱ mRNA content was used to investigate the effect of PGA/PLA scaffold material on tissue engineering cartilage reconstruction of knee osteoarthritis. Results:Cartilage tissue was scored according to international histological scoring criteria. The cartilage of the k group was severely fibrotic, the surface of the joint was irregular, and there were many fluids in the cavity, and the defect was severe. In the T group, the fibrosis phenomenon was alleviated, the surface was regular, the area of the effusion in the cavity was reduced, no depression occurred, and the surface of the joint was regular. Arthritis symptoms and cartilage tissue scores were significantly improved in group T and group k (P<0.05). The chondrocytes in the H group were densely distributed, and the k group was disorderly and sparse. In the H group, the cartilage layer of the knee joint was thick, and the cartilage layer in the k group was thin and damaged. The chondrocytes in the H group were located in the lacuna in the stroma, and there were cartilage sacs. The k group had obvious defects and no cartilage capsule structure (all P<0.05). Compared with the k group, the cartilage layer at the knee joint was thicker and the cells were densely distributed. The cartilage sac of some cells could be seen (P<0.05). There were more stromal collagen positive cells in the knee joint of group H. The number of cells in the k group was the least, the cartilage matrix was the most severely damaged, and the chondrocytes and the bone matrix were loose. Compared with group T and group k, the damage of positive cartilage matrix was reduced, and the number of cells was significantly increased (P<0.05). Result:There was a significant difference between the k group and the T group (P<0.05). Western blot was used to immunoblot the content of Col-Ⅱ protein in cartilage tissues of group H, k and T. According to the gray scale analysis, the content of Col-Ⅱ protein was the highest in group H, and the lowest in group k, group T and k. Compared with the group, the content of Col-Ⅱ protein was significantly increased (P<0.05). The expression of Col-Ⅱ mRNA in cartilage tissue of H group was the highest in group H, and the expression of Col-Ⅱ mRNA was the lowest in group k. The expression of Col-Ⅱ mRNA was significantly increased in group T and group k (all P< 0.05). Conclusions:PGA/PLA was used as scaffold material to reconstruct knee osteochondral tissue by tissue engineering method, which has obvious therapeutic effect on knee osteoarthritis.

The development of tissue engineering corneal scaffold:which one the history will choose?

Since the 21st century,the development of corneal tissue engineering technology has been developing rapidly.With the progress of biomaterials,cell culture and tissue engineering technology,tissue engineering cornea has gained great development in both basic scientific research and clinical application.In particular,tissue engineered corneal scaffolds are the core components of tissue engineered corneas.It is the focus of current research on tissue engineering cornea to search for scaffolds with good biocompatibility,high safety and good biomechanical properties.In this paper,the recent research progress of tissue engineering corneal materials is reviewed.

A Systematic Review of Animal and Clinical Studies on the Use of Scaffolds for Urethral Repair

Replacing urethral tissue with functional scaffolds has been one of the challenging problems in the field of urethra reconstruction or repair over the last several decades. Various scaffold materials have been used in animal studies, but clinical studies on use of scaffolds for urethral repair are scarce. The aim of this study was to review recent animal and clinical studies on the use of different scaffolds for urethral repair, and to evaluate these scaffolds based on the evidence from these studies. Pub Med and OVID databases were searched to identify relevant studies, in conjunction with further manual search. Studies that met the inclusion criteria were systematically evaluated. Of 555 identified studies, 38 were included for analysis. It was found that in both animal and clinical studies, scaffolds seeded with cells were used for repair of large segmental defects of the urethra, such as in tubular urethroplasty. When the defect area was small, cell-free scaffolds were more likely to be applied. A lot of pre-clinical and limited clinical evidence showed that natural or artificial materials could be used as scaffolds for urethral repair. Urinary tissue engineering is still in the immature stage, and the safety, efficacy, cost-effectiveness of the scaffolds are needed for further study.

Multi-porous electroactive poly(L-lactic acid)/ polypyrrole composite micro/nano fibrous scaffolds promote neurite outgrowth in PC12 cells

In this study, poly（L-lactic acid）/ammonium persulfate doped-polypyrrole composite fibrous scaffolds with moderate conductivity were produced by combining electrospinning with in situ polymerization. PC12 cells were cultured on these fibrous scaffolds and their growth following electrical stimulation （0-20.0 μA stimulus intensity, for 1-4 days） was observed using inverted light microscopy, and scanning electron microscopy coupled with the MTT cell viability test. The results demonstrated that the poly（L-lactic acid）/ammonium persulfate doped-polypyrrole fibrous scaffold was a dual multi-porous micro/nano fibrous scaffold. An electrical stimulation with a current intensity 5.0- 10.0 μAfor about 2 days enhanced neuronal growth and neurite outgrowth, while a high current intensity （over 15.0 μA） suppressed them. These results indicate that electrical stimulation with a moderate current intensity for an optimum time frame can promote neuronal growth and neurite outgrowth in an intensity- and time-dependent manner.

High Value Materials from the Forests

The design, process and synthesis of high value composite materials from forests in scientific research has been widely discussed in recent times ensuring greater awareness and accessibility to its associated communities and the economy in general. Raw materials obtained from the forests can be multi-folded in its use as a virgin source of an energy provider such as wooden blocks to more complex processed material development. In this paper, we will be focusing on the latter related to sustainable development of rosins. Rosins are exudates of pine resins which consist of hydrophobic characteristics that are widely used as a precursor for many applications without significant alterations. We discuss the nature, process and its support in composite material. The composite material has been tailored with related to chemical and physical properties. Chemically rosins contain free carboxyl acid functional group and carbon-carbon double bonds which are potent to react with other reactive species to facilitate various intermediates. Here we have looked at its reaction intermediates and subsequent products for composite material of high value using environmentally friendly methodologies, such as solvent free methods. Biodegradable polymer incorporated composite scaffolds using rosins are studied to tailor the bioactivity. We treat the eco-friendly pine resins which is biocompatible to complement the biopolymers as the process of extracting rosin from pine resin is a particular green process, involving only a natural product (pine resin) and producing no waste. The paper discusses the preparation of composite scaffolds for use in tissue engineering applications.

3D bioactive composite scaffolds for bone tissue engineering

Bone is the second most commonly transplanted tissue worldwide,with over four million operations using bone grafts or bone substitute materials annually to treat bone defects.However,significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma,cancer,infection and arthritis.Developing bioactive three-dimensional(3D)scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering(BTE).A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts.However,individual groups of materials including polymers,ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone.Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds.This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers,hydrogels,metals,ceramics and bio-glasses in BTE.Scaffold fabrication methodology,mechanical performance,biocompatibility,bioactivity,and potential clinical translations will be discussed.

Evaluating and Modeling the Mechanical Properties of the Prepared PLGA/nano-BCP Composite Scaffolds for Bone Tissue Engineering

In this paper, preparation of nano-biphasic calcium phosphate （nBCP）, mechanical behavior and load-bearing of poly （lactide-co-glycolide） （PLGA） and PLGA/nBCP are presented. The nBCP with composition of 63/37 （w/w） HA/-TCP （hydroxyapatite/fl-tricalcium phosphate） was produced by heating of bovine bone at 700℃. Composite scaffolds were made by using PLGA matrix and 10-50 wt% nBCP powders as reinforcement material. All scaffolds were prepared by thermally induced solid-liquid phase separation （TIPS） at -60~C under 4 Pa （0.04 mbar） vacuum. The results of elastic modulus testing were adjusted with Ishai-Cohen and Narkis models for rigid polymeric matrix and compared to each other. PLGA/nBCP scaffolds with 30 wt% nBCP showed the highest value of yield strength among the scaffolds. In addition, it was found that by increasing the nBCP in scaffolds to 50 wt%, the modulus of elasticity was highly enhanced. However, the optimum value of yield strength was obtained at 30 wt% nBCP, and the agglomeration of reinforcing particles at higher percentages caused a reduction in yield strength. It is clear that the elastic modulus of matrix has the significant role in elastic modulus of scaffolds, as also the size of the filler particles in the matrix.

中药有效成分结合骨组织工程材料用于骨修复

背景:如何修复骨缺损一直以来是临床难题,中药有效成分在骨修复方面具有良好的生物活性与治疗效果,将中药有效成分与组织工程材料相结合在骨修复领域具有广阔的前景。不同中药有效成分与支架的组合在作用关系方面具有相似之处。目的:搜集常见的中药有效成分与支架材料组合的案例,基于七情配伍的启发将组织工程支架与中药有效成分类比为产生配伍关系的两类中药,以二者的作用关系为纲进行归纳总结。方法:检索1998年1月至2024年1月Pub Med和中国知网数据库中发表的相关文献,英文检索词:“traditional Chinese medicine,Chinese medicine,traditional Chinese medicine monomers,bone defect,bone repair,bone tissue engineering,tissue engineering,scaffold”,中文检索词:“中药,中药有效成分,中药单体,骨组织工程,骨组织工程支架,支架,组织工程,骨缺损,骨修复”,最终纳入88篇文献进行综述分析。结果与结论:(1)组织工程支架材料与中药有效成分各自均在骨修复领域有广泛的运用,二者在成骨方面优势明显但仍有许多缺陷,许多研究致力于将二者制备成复合材料,希望通过二者间的相互作用发挥减毒增效作用。(2)一些药物与材料在成骨、抗菌、促血管生成方面能互相促进,增强原有的效果,受到传统方剂配伍观念的启发,文章将其归纳为“相须”关系,并举实例佐证。(3)一些药物能提高材料的强度,而某些材料能对负载于其上的药物实现缓释控释效果、增加载药量与稳定性,或是进行靶向递送,文章将这种单方面的提升效果归纳为“相使”关系。(4)一些中药与材料搭配使用能减少对方的毒副反应,文章将这种减毒关系归纳为“相畏相杀”。(5)文章得出了一个由七情配伍关系启发、基于作用关系分类的关于中药复合支架的全新视角,将中药传统观念引入组织工程领域,为后续复合支架的研究者提供新的研究思路,并在选材搭配方面提供一定的便利。

生物矿物用于制备骨组织工程支架的工艺及性能

背景:近年来,生物矿物用于骨组织工程支架制备的方法得到了广泛研究,包括溶剂铸造法、冷冻干燥法、3D打印等,然而,生物矿物种类多样、成分复杂,对支架性能的影响和制备工艺的要求各不相同,尚需对其适用性进行系统研究。目的:探索生物矿物的研磨及筛选工艺,评价生物矿物与高分子基体复合材料的溶液流变特性、亲水性、力学性能和生物相容性。方法:选取5种具有代表性的生物矿物,分别为鳖甲、蛋壳、海螵蛸、鹿角霜和珍珠,将5种生物矿物研磨成粉并筛选,按照特定比例分别与聚己内酯混合制备成复合材料。通过对粉末的元素成分、粒径分布以及复合材料的溶液流变特性、亲水性、力学性能和生物相容性进行测试,探究生物矿物在骨组织工程中应用的可行性。结果与结论:①大多数生物矿物粉末遵循研磨时间越长粒径越小的规律,通过过筛等方法可以分离获取所需粒度范围内的生物矿物颗粒。元素面扫和傅里叶红外光谱分析表明,这5种生物矿物的主要无机矿物成分为碳酸钙和磷酸钙,都含有C、O、P、Ca 4种元素。②使用1,4-二氧六环溶解聚己内酯并添加生物矿物粉末制备支架的方法,不会导致复合材料成分上发生显著变化,并且不会降低复合材料的生物相容性。生物矿物粉末的加入能够改善聚己内酯材料的亲水性和可3D打印性,但会导致复合材料力学性能的下降。③结果表明,将生物矿物粉末应用于骨组织工程支架时应注意粉末添加比例的选择,以平衡复合材料的亲水性、可打印性和力学性能。

PLGA/赖氨酸接枝氧化石墨烯纳米粒子复合支架对MC3T3细胞成骨分化的影响

背景:骨损伤后如何有效促进骨再生和骨重建一直是临床骨修复研究中的关键问题,利用生物和降解材料搭载生物活性因子在骨修复中具有优秀的应用前景。目的:探究赖氨酸接枝氧化石墨烯(LGA-g-GO)纳米粒子改性的聚乳酸-羟基乙酸共聚物(PLGA)复合支架对成骨分化及新骨形成的影响。方法:将PLGA溶于二氯甲烷中,利用溶剂挥发法制备PLGA支架;将氧化石墨烯均匀分散于PLGA溶液中制备PLGA/GO复合支架;利用化学接枝法制备LGA-g-GO纳米粒子,将LGA-g-GO纳米粒子按不同的质量比(1%,2%,3%)与PLGA共混构建出PLGA/LGA-g-GO复合支架。表征5组支架的微观形貌、亲水性、蛋白吸附能力。将MC3T3细胞分别接种于5组支架表面,检测细胞增殖与成骨分化情况。结果与结论:①扫描电镜下可见PLGA支架表面光滑平坦,其余4组支架表面粗糙,并且随着LGA-g-GO纳米粒子加入量的增加,复合支架的表面粗糙程度加重;PLGA/LGA-g-GO(3%)复合支架的水接触角低于其他4组支架(P<0.05);PLGA/LGA-g-GO(1%,2%,3%)复合支架的蛋白吸附能力强于PLGA、PLGA/GO支架(P<0.05);②CCK-8检测显示,PLGA/LGA-g-GO(2%,3%)复合支架可促进MC3T3细胞的增殖;碱性磷酸酶染色与茜素红染色显示,PLGA/LGA-g-GO(2%,3%)组细胞碱性磷酸酶活性高于其他3组(P<0.05),PLGA/GO组、PLGA/LGA-g-GO(1%,2%,3%)组钙沉积多于PLGA组(P<0.05);③结果表明,PLGA/LGA-g-GO复合支架能够促进成骨细胞的增殖和成骨分化,有利于骨损伤后的骨再生和骨重建。

基质细胞衍生因子1修饰左旋聚乳酸多孔微球促进软骨细胞增殖和组织形成

背景:二维培养条件下的软骨细胞增殖及表型维持受限,多孔微球作为支架材料可提供三维培养环境,以更好地模拟体内生长条件。基质细胞衍生因子1是有强趋化效力的稳态细胞因子,能够促进细胞的黏附与增殖。目的:明确接枝基质细胞衍生因子1左旋聚乳酸多孔微球对软骨细胞生物学特性及软骨组织形成的影响。方法:(1)体外验证不同质量浓度基质细胞衍生因子1对兔软骨细胞增殖、迁移、表型维持的影响。(2)采用复乳法制备左旋聚乳酸多孔微球,利用碳二亚胺法将基质细胞衍生因子1接枝于左旋聚乳酸多孔微球上,通过酶联免疫吸附实验及孵育基质细胞衍生因子1特异荧光抗体验证接枝情况。(3)将兔软骨细胞分别接种于左旋聚乳酸多孔微球、接枝基质细胞衍生因子1左旋聚乳酸多孔微球上,检测细胞增殖与黏附。(4)在裸鼠背部皮下分别植入甲基丙烯酰胺基明胶-软骨细胞复合体(对照组)、左旋聚乳酸多孔微球-甲基丙烯酰胺基明胶-软骨细胞复合体(多孔微球组)、接枝基质细胞衍生因子1左旋聚乳酸多孔微球-甲基丙烯酰胺基明胶-软骨细胞复合体(多孔微球修饰组),8周后取材,分别进行组织学染色与成软骨相关基因qRT-PCR检测。结果与结论:(1)相较于0,1 000 ng/mL基质细胞衍生因子1,500 ng/mL基质细胞衍生因子1可促进软骨细胞的增殖与迁移,提升软骨细胞内Ⅱ型胶原、弹性蛋白、增殖细胞核抗原、Bcl-2 mRNA表达;(2)基质细胞衍生因子1成功接枝于左旋聚乳酸多孔微球上,接枝率为93.75%;(3)相较于左旋聚乳酸多孔微球,接枝基质细胞衍生因子1左旋聚乳酸多孔微球可促进软骨细胞的增殖、黏附;(4)裸鼠皮下植入8周后,相较于对照组、多孔微球组,多孔微球修饰组具有更明显的软骨陷窝结构、更丰富的软骨特异性基质和Ⅱ型胶原沉积,弹性蛋白、Ⅱ型胶原、增殖细胞核抗原、Bcl-2 mRNA表达升高。结果表明:接枝基质细胞衍生因子1左旋聚乳酸多孔微球有利于软骨细胞的黏附、增殖、表型维持以及体内软骨组织形成。

Magnesium incorporated chitosan based scaffolds for tissue engineering applications

Chitosan based porous scaffolds are of great interest in biomedical applications especially in tissue engineering because of their excellent biocompatibility in vivo,controllable degradation rate and tailorable mechanical properties.This paper presents a study of the fabrication and characterization of bioactive scaffolds made of chitosan(CS),carboxymethyl chitosan(CMC)and magnesium gluconate(MgG).Scaffolds were fabricated by subsequent freezing-induced phase separation and lyophilization of polyelectrolyte complexes of CS,CMC and MgG.The scaffolds possess uniform porosity with highly interconnected pores of 50-250 μm size range.Compressive strengths up to 400 kPa,and elastic moduli up to 5 MPa were obtained.The scaffolds were found to remain intact,retaining their original threedimensional frameworks while testing in in-vitro conditions.These scaffolds exhibited no cytotoxicity to 3T3 fibroblast and osteoblast cells.These observations demonstrate the efficacy of this new approach to preparing scaffold materials suitable for tissue engineering applications.

Electrospun nanofiber/hydrogel composite materials and their tissue engineering applications

Electrospun nanofiber/hydrogel composites combine the excellent biochemical properties of hydrogel with the biomimetic nature of electrospun fibers,and have attracted widespread attention in the last few years.Besides,nanofiber/hydrogel composites with tunable mechanical properties can mimic the microstructure of extracellular matrix(ECM)of various tissues and the microenvironment of different cells.These features enable electrospun fiber/hydrogel composites have uniquely advantageous for tissue repair.However,a comprehensive review of electrospun fiber/hydrogel composites as tissue engineering scaffolds is still lacking.Thus,this article systematically reviewed the preparation of electrospun fiber/hydrogel composites and their application in tissue engineering.First,the preparation strategies of electrospun fiber/hydrogel composites are classified and discussed.Second,the application of electrospun fiber/hydrogel-based scaffolds in tissue engineering,involving skin,blood vessel,nerve,bone and other tissue engineering,are summarized.Finally,future research directions for functional electrospun fiber/hydrogel scaffold materials are proposed.

3D printing method for bone tissue engineering scaffold

3D printing technology is an emerging technology.It constructs solid bodies by stacking materials layer by layer,and can quickly and accurately prepare bone tissue engineering scaffolds with specific shapes and structures to meet the needs of different patients.The field of life sciences has received a great deal of attention.However,different 3D printing technologies and materials have their advantages and disadvantages,and there are limitations in clinical application.In this paper,the technology,materials and clinical applications of 3D printed bone tissue engineering scaffolds are reviewed,and the future development trends and challenges in this field are prospected.

3D打印生物墨水在组织修复与再生医学中的应用

背景:通过选用合适的生物墨水,3D打印技术可用以制造人体组织和器官的代替物,并在人体内发挥作用。近些年来3D打印技术发展迅速,在再生医学中有着巨大的应用潜力。目的:介绍3D打印用生物墨水的类型,并综述生物墨水的分类、应用、优缺点及未来愿景。方法:以“3D printing,Biological ink,Tissue engineering,hydrogel,Synthetic material,Cytoactive factor,3D打印、生物墨水、组织工程”为检索词,运用计算机检索2000-2022年以来发表在PubMed、CNKI数据库中的相关文献,最终纳入83篇进行综述。结果与结论:在过去的几十年里,生物3D打印技术发展迅速,在组织工程和生物医学等各个领域都受到了极大的关注。相对于传统生物支架制造方法在功能性及结构方面受到的限制,3D打印可以更好地模拟生物组织复杂的结构,并且具有合适的力学、流变学和生物学特性。生物墨水是3D打印中必不可少的一部分,通过生物材料制备的生物墨水,经打印后产生的生物支架在组织修复和再生医学等方面有着巨大的科研潜力及临床意义,其材料的研究本身也越来越受到专家们的重视。3D打印生物墨水的材料各种各样,有天然材料也有合成材料,还有一些不需要任何额外生物材料的细胞聚集体,并且各种材料在实际运用中的功效各不相同。未来会有越来越多的生物墨水被研制用于组织工程,需要通过充足的实验模拟及设备测试来对生物墨水的可打印性进行分析,从而满足实际的医用需求。