Hippocampal Neuron-Derived Extracellular Matrix Coated Nanofibrous Scaffold for Neural Tissue Engineering

The aim of this study is to prepare poly-L-lactide(PLLA)electrospun nanofibrous scaffolds coated with hippocampal neuron-derived extracellular matrix(N-ECM)and construct a novel neural tissue engineering scaffold.Neonatal rat hippocampal neurons were seeded on PLLA nanofibers,and then decellularized to derive a cell-free extracellular matrix loaded N-ECM/PLLA modified scaffolds.The morphology and ingredients of N-ECM/PLLA were observed by scanning electron microscopy(SEM)and immunofluorescence staining respectively,and the cytocompatibility of the composite scaffolds was characterized by cell count kit-8(CCK-8)assay.The N-ECM was clearly identified loading on scaffolds when being imaged via SEM and immunofluorescence staining results showed that the N-ECM was made up of fibronectin and laminin.Most importantly,compared with tissue culture polystyrene and pure scaffolds,N-ECM/PLLA scaffolds could effectively facilitate the proliferation of rat adrenal neuroma cells(PC12 cells),indicating their better cell compatibilities.Based on the combination of N-ECM and PLLA biomaterials,the present study has fabricated a unique and versatile neural tissue engineering scaffold,offering a new thought for future neural tissue engineering.

The Effects of Extracellular Matrix on Tissue Engineering Construction of Cartilage in Vitro

The effects of various cartilage extracellular matrix on the construction of rabbit growth plate cartilage tissue in vitro were studied. The results show that collagen, proteoglycan and hyaluronic acid can promote the growth of cultured chondrocytes but the effects of various cartilage extracellular matrix(ECM)on chondrocyte differentiation are different. Collagen can promote the hypertrophy of chondrocytes while proteoglycan and hyaluronic acid inhibit the transition of mature chondrocytes into hypertrophied chondrocytes.

Smart scaffolds in bone tissue engineering: A systematic review of literature

AIM: To improve osteogenic differentiation and attachment of cells.METHODS: An electronic search was conducted inPub Med from January 2004 to December 2013. Studies which performed smart modifications on conventional bone scaffold materials were included. Scaffolds with controlled release or encapsulation of bioactive molecules were not included. Experiments which did not investigate response of cells toward the scaffold(cell attachment, proliferation or osteoblastic differentiation) were excluded. RESULTS: Among 1458 studies, 38 met the inclusion and exclusion criteria. The main scaffold varied extensively among the included studies. Smart modifications included addition of growth factors(group Ⅰ-11 studies), extracellular matrix-like molecules(group Ⅱ-13 studies) and nanoparticles(nano-HA)(group Ⅲ-17 studies). In all groups, surface coating was the most commonly applied approach for smart modification of scaffolds. In group I, bone morphogenetic proteins were mainly used as growth factor stabilized on polycaprolactone(PCL). In group Ⅱ, collagen 1 in combination with PCL, hydroxyapatite(HA) and tricalcium phosphate were the most frequent scaffolds used. In the third group, nano-HA with PCL and chitosan were used the most. As variable methods were used, a thorough and comprehensible compare between the results and approaches was unattainable.CONCLUSION: Regarding the variability in methodology of these in vitro studies it was demonstrated that smart modification of scaffolds can improve tissue properties.

Differentiation of mesenchymal stem cells into neuronal cells on fetal bovine acellular dermal matrix as a tissue engineered nerve scaffold

The purpose of this study was to assess fetal bovine acellular dermal matrix as a scaffold for supporting the differentiation of bone marrow mesenchymal stem cells into neural cells fol-lowing induction with neural differentiation medium. We performed long-term, continuous observation of cell morphology, growth, differentiation, and neuronal development using several microscopy techniques in conjunction with immunohistochemistry. We examined speciifc neu-ronal proteins and Nissl bodies involved in the differentiation process in order to determine the neuronal differentiation of bone marrow mesenchymal stem cells. The results show that bone marrow mesenchymal stem cells that differentiate on fetal bovine acellular dermal matrix display neuronal morphology with unipolar and bi/multipolar neurite elongations that express neuro-nal-speciifc proteins, includingβIII tubulin. The bone marrow mesenchymal stem cells grown on fetal bovine acellular dermal matrix and induced for long periods of time with neural differen-tiation medium differentiated into a multilayered neural network-like structure with long nerve ifbers that was composed of several parallel microifbers and neuronal cells, forming a complete neural circuit with dendrite-dendrite to axon-dendrite to dendrite-axon synapses. In addition, growth cones with filopodia were observed using scanning electron microscopy. Paraffin sec-tioning showed differentiated bone marrow mesenchymal stem cells with the typical features of neuronal phenotype, such as a large, round nucleus and a cytoplasm full of Nissl bodies. The data suggest that the biological scaffold fetal bovine acellular dermal matrix is capable of supporting human bone marrow mesenchymal stem cell differentiation into functional neurons and the subsequent formation of tissue engineered nerve.

Peripheral nerve allograft prepared by an acellular,hypotonic tissue engineering method

BACKGROUND：Tissue engineered acellular nerves are good autologous nerve substitutes. Acellular peripheral nerves prepared using a conventional chemical extraction method cause a great deal of damage to nerve structures, and the allograff affects the nerve regeneration following transplantation.OBJECTIVE：To prepare peripheral nerve grafts through an acellular tissue engineering method, and observe their histology, ultrastructure, protein components and histocompatibility.DESIGN, TIME AND SETTING：A randomized, controlled, in vivo nerve tissue engineering experiment was performed at the Department of Biochemistry and Molecular Biology, Shenyang Medical College, China, from September 2006 to June 2007.MATERIALS：Triton X-100, Pepstatin A, Aprotinin and Leupeptin were purchased from Sigma, USA; Tris （hydroxymethyl） aminomethane was purchased from Gibco, USA.METHODS：The bilateral sciatic nerves of Wistar rats were harvested, treated with 0.05 mol/L Tris-HCI buffer, followed by proteinase inhibitor and Triton X-100 to prepare acellular peripheral nerves. The nerves were implanted in the quadriceps femoris muscle of healthy Wistar rats.MAIN OUTCOME MEASURES：Tissue structure and ultrastructure of acellular peripheral nerves were observed by optical microscopy and scanning electron microscopy. Growth associated proteins were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Nerve allograft and the surrounding muscles were observed by hematoxylin-eosin staining.RESULTS：Acellular treatment eliminated Schwann cells, epineurium or perineurium cells, myelin sheaths and axons of nerve fibers in normal peripheral nerves, while the spatial structure, comprising basement membrane tubes of Schwann cells and the extracellular matrix of perineurium and nerve fascicles was maintained. Protein bands at the region of 30 kD were no longer visible, had slightly decreased at 43 kD and remained unchanged at 65 kD. Following implantation for 7 days, epineurium cells were absorbed. However, increased fibroblasts, decreased newly-generated capillaries and maturation of granulation tissue were observed.CONCLUSION：The acellular nerve allograft prepared through the use of a hypotonic, acellular method displays good histocompatibility, eliminates immune substances and retains growth associated proteins that induce the growth of the neural axis. In addition, this method provides an ideal scaffold to construct artificial nerves.

Decellularized extracellular matrix-based composite scaffolds for tissue engineering and regenerative medicine

Despite the considerable advancements in fabricating polymeric-based scaffolds for tissue engineering,the clinical transformation of these scaffolds remained a big challenge because of the difficulty of simulating native organs/tissues'microenvironment.As a kind of natural tissue-derived biomaterials,decellularized extracellular matrix(dECM)-based scaffolds have gained attention due to their unique biomimetic properties,providing a specific microenvironment suitable for promoting cell proliferation,migration,attachment and regulating differentiation.The medical applications of dECM-based scaffolds have addressed critical challenges,including poor mechanical strength and insufficient stability.For promoting the reconstruction of damaged tissues or organs,dif-ferent types of dECM-based composite platforms have been designed to mimic tissue microenvironment,including by integrating with natural polymer or/and syntenic polymer or adding bioactive factors.In this review,we summarized the research progress of dECM-based composite scaffolds in regenerative medicine,highlighting the critical challenges and future perspectives related to the medical application of these composite materials。

Decellularised extracellular matrix-based injectable hydrogels for tissue engineering applications

Decellularised extracellular matrix(dECM)is a biomaterial derived from natural tissues that has attracted considerable attention from tissue engineering researchers due to its exceptional biocompatibility and malleability attributes.These advantageous properties often facilitate natural cell infiltration and tissue reconstruction for regenerative medicine.Due to their excellent fluidity,the injectable hydrogels can be administered in a liquid state and subsequently formed into a gel state in vivo,stabilising the target area and serving in a variety of ways,such as support,repair,and drug release functions.Thus,dECM-based injectable hydrogels have broad prospects for application in complex organ structures and various tissue injury models.This review focuses on exploring research advances in dECM-based injectable hydrogels,primarily focusing on the applications and prospects of dECM hydrogels in tissue engineering.Initially,the recent developments of the dECM-based injectable hydrogels are explained,summarising the different preparation methods with the evaluation of injectable hydrogel properties.Furthermore,some specific examples of the applicability of dECM-based injectable hydrogels are presented.Finally,we summarise the article with interesting prospects and challenges of dECM-based injectable hydrogels,providing insights into the development of these composites in tissue engineering and regenerative medicine.

Engineering an extracellular matrix-functionalized,load-bearing tendon substitute for effective repair of large-to-massive tendon defects

A significant clinical challenge in large-to-massive rotator cuff tendon injuries is the need for sustaining high mechanical demands despite limited tissue regeneration,which often results in clinical repair failure with high retear rates and long-term functional deficiencies.To address this,an innovative tendon substitute named“BioTenoForce”is engineered,which uses(i)tendon extracellular matrix(tECM)’s rich biocomplexity for tendon-specific regeneration and(ii)a mechanically robust,slow degradation polyurethane elastomer to mimic native tendon’s physical attributes for sustaining long-term shoulder movement.Comprehensive assessments revealed outstanding performance of BioTenoForce,characterized by robust core-shell interfacial bonding,human rotator cuff tendon-like mechanical properties,excellent suture retention,biocompatibility,and tendon differentiation of human adipose-derived stem cells.Importantly,BioTenoForce,when used as an interpositional tendon substitute,demonstrated successful integration with regenerative tissue,exhibiting remarkable efficacy in repairing large-to-massive tendon injuries in two animal models.Noteworthy outcomes include durable repair and sustained functionality with no observed breakage/rupture,accelerated recovery of rat gait performance,and>1 cm rabbit tendon regeneration with native tendon-like biomechanical attributes.The regenerated tissues showed tendon-like,wavy,aligned matrix structure,which starkly contrasts with the typical disorganized scar tissue observed after tendon injury,and was strongly correlated with tissue stiffness.Our simple yet versatile approach offers a dual-pronged,broadly applicable strategy that overcomes the limitations of poor regeneration and stringent biomechanical requirements,particularly essential for substantial defects in tendon and other load-bearing tissues.

Growth factor delivery using extracellular matrix-mimicking substrates for musculoskeletal tissue engineering and repair

Therapeutic approaches for musculoskeletal tissue regeneration commonly employ growth factors(GFs)to influence neighboring cells and promote migration,proliferation,or differentiation.Despite promising results in preclinical models,the use of inductive biomacromolecules has achieved limited success in translation to the clinic.The field has yet to sufficiently overcome substantial hurdles such as poor spatiotemporal control and supraphysiological dosages,which commonly result in detrimental side effects.Physiological presentation and retention of biomacromolecules is regulated by the extracellular matrix(ECM),which acts as a reservoir for GFs via electrostatic interactions.Advances in the manipulation of extracellular proteins,decellularized tissues,and synthetic ECM-mimetic applications across a range of biomaterials have increased the ability to direct the presentation of GFs.Successful application of biomaterial technologies utilizing ECM mimetics increases tissue regeneration without the reliance on supraphysiological doses of inductive biomacromolecules.This review describes recent strategies to manage GF presentation using ECM-mimetic substrates for the regeneration of bone,cartilage,and muscle.

Biocompatibility Evaluation of Vessel Extracellular Matrix as a Matrix for Urethral Reconstruction

The objective of this study was to evaluate the biocompatibility of vessel extracellular matrix （VECM） from rabbit and to discuss the feasibility of vessel extracellular matrix as a matrix for urethral reconstruction. Primary cultured bladder smooth muscle cells isolated from New Zealand rabbits were implanted on VECM .The effects of VECM on rabbit bladder smooth muscle cells （RBSMCs） metabolic activity, attachment, proliferation were monitored in vitro with the aid of an inverted light microscope and a scanning electron microscope. The cell viability was monitored by MTT（methythiazolye tetrazolium bromide） after 1, 3, 5 days seeding. The in vivo tissue response to VECM was investigated by implanting them into the subcutaneous of rabbits. VECM exhibited a nontoxic and bioactive effect on RBSMCs. RBSMCs could be attached to and proliferated on VECM and maintained their morphologies. MTT assay showed RBSMCs cultured with the extracts of VECM were not significantly different from those of negative controls. In vivo, VECM demonstrated a favorable tissue compatibility without tissue necrosis, fibrosis and other abnormal response. VECM exhibited nontoxic and bioactive effects on RBSMC. It is a suitable material for urethral reconstruction.

Liver bioengineering:Current status and future perspectives

The present review aims to illustrate the strategies that are being implemented to regenerate or bioengineer livers for clinical purposes.There are two general pathways to liver bioengineering and regeneration.The first consists of creating a supporting scaffold,either synthetically or by decellularization of human or animal organs,and seeding cells on the scaffold,where they will mature either in bioreactors or in vivo.This strategy seems to offer the quickest route to clinical translation,as demonstrated by the development of liver organoids from rodent livers which were repopulated with organ specific cells of animal and/or human origin.Liver bioengineering has potential for transplantation and for toxicity testing during preclinical drug development.The second possibility is to induce liver regeneration of dead or resected tissue by manipulating cell pathways.In fact,it is well known that the liver has peculiar regenerative potential which allows hepatocyte hyperplasia after amputation of liver volume.Infusion of autologous bone marrow cells,which aids in liver regeneration,into patients was shown to be safe and to improve their clinical condition,but the specific cells responsible for liver regeneration have not yet been determined and the underlying mechanisms remain largely unknown.A complete understanding of the cell pathways and dynamics and of the functioning of liver stem cell niche is necessary for the clinical translation of regenerative medicine strategies.As well,it will be crucial to elucidate the mechanisms through which cells interact with the extracellular matrix,and how this latter supports and drives cell fate.

Nanofibrous Scaffold Containing Osteoblast-Derived Extracellular Matrix for the Proliferation of Bone Marrow Mesenchymal Stem Cells

Extracellular matrix( ECM) plays a prominent role in establishing and maintaining an appropriate microenvironment for tissue regeneration. The aims of this study were to construct a tissue engineered scaffold by reconstituting osteoblast cell-derived ECM( O-ECM) on the electrospun nanofibrous scaffold,and further to evaluate its subsequent application for promoting the proliferation of bone marrow mesenchymal stem cells( BMSCs). To engineer a biomimetic scaffold, calvarial osteoblasts and electrospun poly-llactic acid( PLLA) nanofibers were prepared and subjected to decellularize for O-ECM deposition. To evaluate and characterize the O-ECM/PLLA scaffold, the morphology was examined and several specific mark proteins of osteoblasts matrix were evaluated.Furthermore,the cell counting kit-8( CCK-8) assay was used to detect the proliferation of the BMSCs cultivated on the O-ECM/PLLA scaffold. The results indicated O-ECM/PLLA scaffold was loaded with Collagen I, Fibronectin, and Laminin, as the composition of the marrow ECM. After decellularization,O-ECM deposition was observed in O-ECM/PLLA scaffold. Moreover,the O-ECM/PLLA scaffold could significantly enhance the proliferation of BMSCs,suggesting better cytocompatibility compared to the other groups tested. Taken together,a biomimetic scaffold based on the joint use of O-ECM and PLLA biomaterials,which represents a promising approach to bone tissue engineering, facilitates the expansion of BMSCs in vitro.

小肠黏膜下层脱细胞基质复合外泌体构建组织工程尿道

背景:小肠黏膜下层脱细胞基质已被临床与基础研究证实可用于尿道的修复重建,但其单独应用时存在宿主细胞生长缓慢、支架血管化不足而成活困难、重建尿道狭窄梗阻等问题,仅适用于较短的尿道狭窄。目的:探讨应用小肠黏膜下层脱细胞基质复合外泌体构建组织工程尿道的可行性。方法:从新西兰大白兔骨髓间充质干细胞中分离提取外泌体;制备猪小肠黏膜下层脱细胞基质,将外泌体负载于小肠黏膜下层脱细胞基质上。将小肠黏膜下层脱细胞基质-外泌体(PKH26染料标记)复合物与脐静脉内皮细胞共培养12 h,观察细胞摄取外泌体情况。选取生长状态良好的脐静脉内皮细胞,分3组培养:空白组常规培养,对照组加入小肠黏膜下层脱细胞基质,实验组加入小肠黏膜下层脱细胞基质-外泌体复合物,通过划痕实验、成管实验、血管生成因子分泌检测评估血管生成情况。取30只新西兰大白兔,建立长段(3 cm)尿道缺损模型,采用随机数字表法分3组干预(n=10):单独材料组植入小肠黏膜下层脱细胞基质,对照组植入小肠黏膜下层脱细胞基质-骨髓间充质干细胞复合物,实验组植入小肠黏膜下层脱细胞基质-外泌体复合物,植入后12周进行尿道造影、尿动力学检查及重建尿道切片病理观察。结果与结论:(1)荧光显微镜下可见小肠黏膜下层脱细胞基质中的外泌体可被脐静脉内皮细胞摄取。(2)与空白组、对照组相比,实验组材料可促进脐静脉内皮细胞的迁移、成血管能力以及成血管因子血管内皮生长因子、肝细胞生长因子、白细胞介素8的分泌(P <0.05)。(3)尿道造影结果显示,单独材料组10只兔均出现尿道狭窄,对照组10只兔中2只出现尿道狭窄,实验组10只兔均未出现尿道狭窄。尿动力检查结果显示,单独材料组兔材料植入后12周的最大尿道压高于术前(P <0.05),对照组、实验组兔植入后12周的最大尿道压均低于空白组(P <0.05)。苏木精-伊红、Masson与免疫组化染色显示,单独材料组可见明显的再生上皮层、少量的皮下平滑肌与血管,以纤维组织增生为主,伴有明显炎性细胞浸润;对照组可见较完整的再生上皮与少量胶原,可见大量的皮下血管与平滑肌,伴有炎性细胞浸润;实验组可见完整的再生上皮层与大量的皮下血管、平滑肌,未见明显炎性细胞浸润,实验组AE1/AE3、ɑ-平滑肌肌动蛋白、CD31阳性表达均高于单独材料组、对照组(P <0.05)。(4)结果表明,小肠黏膜下层脱细胞基质-外泌体组织工程尿道可通过促进血管生成来修复尿道缺损。

环状RNA SEC24A对骨关节炎滑膜成纤维细胞增殖和凋亡的影响及机制

背景:滑膜炎症参与骨关节炎的所有阶段,是促进骨关节炎发生发展的关键因素。研究表明,环状RNA(circRNA)在滑膜细胞及软骨细胞增殖、凋亡和细胞外基质降解过程中发挥着重要作用。目的:观察circRNA SEC24A对白细胞介素1β诱导的人滑膜成纤维细胞增殖、凋亡及炎症因子表达的影响。方法:将人滑膜成纤维细胞分为4组,包括对照组、白细胞介素1β组、空载体组、sh-circSEC24A组。除对照组外,其余3组用10 ng/mL白细胞介素1β诱导24 h建立炎症细胞模型;空载体组、sh-circSEC24A组感染空载体病毒和敲低circSEC24A的慢病毒载体。CCK-8法检测细胞增殖情况;流式细胞术检测细胞凋亡情况;ELISA法检测细胞上清液中基质金属蛋白酶9、基质金属蛋白酶13、白细胞介素6和肿瘤坏死因子α水平;Western blot法检测细胞中Bax、Bcl-2、基质金属蛋白酶9、基质金属蛋白酶13、casepase3、cleaved-casepase3、casepase8和cleavedcasepase8蛋白相对表达量。结果与结论:(1)qRT-PCR结果显示,与正常组相比,白细胞介素1β诱导的人滑膜成纤维细胞中circSEC24A表达显著上调;(2)CCK-8法检测sh-circSEC24A组细胞吸光度值显著高于白细胞介素1β组和空载体组(P<0.05),流式细胞术检测sh-circSEC24A组细胞凋亡率显著低于白细胞介素1β组和空载体组(P<0.05);(3)ELISA法检测sh-circSEC24A组人滑膜成纤维细胞上清液中肿瘤坏死因子α和白细胞介素6水平显著低于白细胞介素1β组和空载体组(P<0.01,P<0.001);(4)Western blot结果显示,与白细胞介素1β组和空载体组相比,sh-circSEC24A组促凋亡因子Bax蛋白表达显著下降,抑凋亡因子Bcl-2蛋白表达显著上升(P<0.05);凋亡以及相关活化因子cleaved-casepase3和cleaved-casepase8蛋白表达均降低(P<0.05);(5)ELISA和Western blot结果显示,与白细胞介素1β组和空载体组相比,sh-circSEC24A组基质金属蛋白酶9、基质金属蛋白酶13蛋白表达显著降低(P<0.05)。结果表明,白细胞介素1β诱导的人滑膜成纤维细胞中circSEC24A表达异常增高,敲低circSEC24A表达可促进人滑膜成纤维细胞增殖,抑制细胞凋亡、炎症因子释放和细胞外基质降解,提示circSEC24A可能是早期骨关节炎的重要干预靶点。

Repair of flexor tendon defects of rabbit with tissue engineering method

Objective: To repair rabbit tendon defects with tissue engineering method. Methods: The third passage of fetal skin fibroblast cells was labeled with 5 bromo 2 deoxyuridine (Brdu) and then seeded on human amnion extracellular matrix ( HA ECM ). Using 1 cm long Achilles tendon defects as repairing models in the experimental group, tendon defects were core bridged with polydioxanone (PDS) and then capsulated with the complex of fibroblasts HA ECM . In the control group I, defective tendons were sutured with PDS following the former procedure and capsulated with HA ECM (without fibroblasts). In the control group II, only PDS was applied to connect the defective tendons. Gross examination, light microscopy, scanning electronmicroscopy and biomechanical measurement of the repaired tendons were respectively performed at postoperative 1, 2, 3 month as well as immunohistochemical examination. Results: The optimal cell concentration for seeding fibroblasts was 3.5 ×10 6 cells/ml. Cells grew well and radiated or paralleled on HA ECM . Immunohistochemistry showed that the labeled seed fibroblasts played an important role in tendonization. The results of light microscopy, electron microscopy, and biomechanical assessment suggested that the rate and quality of tendonization in the experimental group was superior to those of the control group I and II. The tensile strength in the experimental group was the greatest, the next was in the control group I, and the worst in the control group II (P< 0.05 ). Conclusions: HA ECM is the excellent carrier for fibroblasts. Fibroblasts HA ECM complex has the capability to repair tendon defect and to tendonize with rapid rate and good performance three months after operation. Its tensile strength is 81.8 % of that of normal tendon.

Tissue-engineered conduit using bladder acellular matrix and bladder epithelial cells for urinary diversion in rabbits

Background For muscle invasive bladder cancer, radical cystectomy is the most effective treatment now and urinary diversion is often necessary. The use of intestinal tissue for urinary diversion is frequently associated with complications. In this study, we aimed to make a tissue-engineered conduit （TEC） using bladder epithelial cells and bladder acellular matrix （BAM） for urinary diversion in rabbits. Methods Bladder epithelial cells of rabbit were cultivated and expanded in vitro, then seeded on BAM, and cultured for 7 days. Then cell-seeded graft was used to make TEC. In the experimental group, most of bladder of the rabbit was removed while bladder trigone was retained. The proximal end of TEC was anastomosed with bladder trigone and the distal end was anastomosed with the abdominal stoma. In the control group, TEC was made using unseeded BAM. Haematoxylin and eosin staining was conducted, respectively, at 1, 2, 4, and 8 weeks postoperatively. Immunohistochemistry was performed 8 weeks postoperatively. Intravenous urography, retrograde pyelography, and cystoscopy of TEC were made at 12 weeks postoperatively. Results All animals were alive in the experimental group. Haematoxylin and eosin staining showed epithelial coverage in TEC. Immunohistochemistry showed anti-cytokeratin AEI/AE3 antibody and anti-ZO1 antibody positive, confirming there were mature and functional epithelial cells on the lumen of TEC. Retrograde pyelography and intravenous urography showed that TEC developed well and that there was no obstruction. In the control group, four rabbits were dead within 2 weeks and scar formation, atresia, and severe hydronephrosis were found. Conclusions We successfully made TEC using BAM and bladder epithelial cells for urinary diversion in rabbits. The lumen of this new TEC covered mature epithelial cells and could prevent urinary extravasation.

细胞外基质硬度对肿瘤进展的影响及治疗策略

背景:细胞外基质是一个复杂的网络结构,不仅为组织构建提供了物理支撑,还在细胞的生存、增殖、分化、死亡等过程中发挥着重要调控作用。细胞外基质生物化学和生物力学性质的异常改变会显著影响肿瘤细胞的增殖、迁移、免疫逃逸及治疗抵抗等行为。硬度是细胞外基质的重要力学特性,基质硬度的异常与肿瘤进展紧密相关。目的:通过梳理近年来关于细胞外基质硬化的机制、高硬度基质对肿瘤进展的影响以及降低基质硬度治疗癌症等方面的最新研究进展,深化对细胞外基质力学特性的理解,提升对肿瘤进展复杂机制的认识,为肿瘤治疗提供新的思路和方向。方法:以“细胞外基质功能,细胞外基质硬度,胶原蛋白沉积交联,细胞外基质僵硬治疗,免疫治疗”为中文检索词,以“extracellular matrix function,extracellular matrix stiffness,collagen deposition cross-linking,extracellular matrix stiffness therapy,immunotherapy”为英文检索词,检索中国知网、PubMed数据库、万方数据库2016年1月至2024年6月发表的相关文献,最终纳入80篇文章进行综述。结果与结论:①细胞外基质中胶原蛋白和弹性蛋白的沉积和过度交联导致基质重塑,进而增加基质硬度,这种硬化激活了cyclin-D1、Rho/ROCK、p-PXN-Rac1-YAP、STAT3/p-STAT3等促癌信号通路,促进了癌细胞的增殖、转移、肿瘤微血管生成及免疫逃逸等恶性行为,加速了肿瘤的进展;②减少基质蛋白的沉积和交联可以降低基质硬度,不仅可以抑制多种促癌信号通路的活化,还能够增强药物在肿瘤部位的渗透和递送,是癌症治疗的新策略;③目前,基于基质降解以降低肿瘤硬度的药物正在研发中,少数药物已进入临床试验阶段,有望为肿瘤治疗提供新的有力武器。

组织工程技术修复颞下颌关节:问题与挑战

背景:颞下颌关节疾病的传统疗法受限于疾病严重程度和个体差异。相比之下,组织工程作为一种新兴治疗方法,可以根据患者具体情况定制个性化治疗方案,减少手术过程中的不确定性,提高治疗效果。目的:综述组织工程修复颞下颌关节的最新研究成果和进展。方法:以“颞下颌关节,组织工程,种子细胞,支架,生长因子,动物模型”为中文检索词,以“temporomandibular joint,tissue engineering,seed cell,scaffold,growth factor,animal model”为英文检索词,分别在PubMed数据库和中国知网进行文献检索,检索时限为各数据库建库时间至2024年3月。通过分析和阅读文献进行筛选,按照排除筛选标准纳入文献,最终纳入57篇文献进行综述。结果与结论:(1)随着生物学、材料学与工程学等技术的发展,颞下颌关节组织工程己取得较大进展,例如种子细胞的筛选、新型支架的开发、生长因子作用机制的探索、多种动物模型的构建等,目前大多数研究尚处于体外实验阶段,动物实验等体内研究尚未大规模开展,组织工程修复颞下颌关节的临床应用还需更多证据支持。(2)尽管颞下颌关节组织工程研究仍存在许多问题和挑战等待解决,依然展现出广阔的临床应用前景,有望在将来成为颞下颌关节疾病出色高效的治疗方式。

甲基丙烯酰化改性真皮细胞外基质水凝胶促进腹壁缺损修复

背景:目前用于填充腹壁缺损部位的合成高分子材料(如聚丙烯或聚酯)不仅缺乏可降解性和生物活性,还难以适应复杂形状伤口需求,因此,找到免疫原性低、组织相容性好的生物活性材料成为腹壁缺损修复研究的热点。目的:制备甲基丙烯酰化改性真皮细胞外基质水凝胶,探讨其在腹壁缺损中的潜在应用价值。方法:(1)依次用0.25%胰蛋白酶、1%Triton X-100对猪真皮进行脱细胞处理,获得真皮细胞外基质;胃蛋白酶消化真皮细胞外基质,经甲基丙烯酸酐改性后光交联形成甲基丙烯酰化改性真皮细胞外基质水凝胶,扫描电镜观察水凝胶的微观形貌,测试其流变学性能、溶胀性等理化性质;(2)将L929成纤维细胞接种到甲基丙烯酰化改性的真皮细胞外基质水凝胶中,检测细胞相容性;(3)将12只SD大鼠随机分为2组(n=6),创建保留腹膜的腹壁缺损模型,聚丙烯组缺损部位填充聚丙烯材料,水凝胶组缺损部位填充甲基丙烯酰化改性真皮细胞外基质水凝胶,两组创面皮肤均用聚丙烯材料覆盖,观察创面愈合情况并进行组织学分析。结果与结论:(1)采用酶解法对猪真皮进行脱细胞后具有良好的脱细胞效果,并且原有的糖胺聚糖及胶原蛋白保留较好。扫描电镜下可见甲基丙烯酰化改性真皮细胞外基质水凝胶为疏松多孔结构,孔径在70-120μm之间,该水凝胶的溶胀比为(16.88±3.24)%,吸水率为(94.24±1.11)%,流变学性能测试表明该水凝胶状态稳定且具有剪切变稀特点,具备可注射性;(2)CCK-8检测与Live/Dead染色结果显示,甲基丙烯酰化改性真皮细胞外基质水凝胶具有良好的细胞相容性;(3)动物实验结果显示,实验组术后7,10,14 d的皮肤创面愈合率高于对照组(P <0.05);皮肤与肌层组织苏木精-伊红、Masson染色显示,与聚丙烯组比较,水凝胶组术后14 d的皮肤创面上皮化情况、毛囊生成、胶原纤维排列及新生血管情况更好,术后28 d的皮肤创面新生组织结构与正常组织相近,并且瘢痕增生较少,术后28 d时可见少量肌肉组织再生;(4)结果表明,甲基丙烯酰化改性真皮细胞外基质水凝胶可促进腹壁缺损大鼠的皮肤创面愈合和肌肉组织再生。