组织工程皮肤研究现状

组织工程皮肤是通过培养功能细胞,将其与细胞外基质及支架材料互相作用,制成的具有生物活性的人工皮肤替代物。组织工程皮肤的发展为修复皮肤创面,重建皮肤功能,治疗皮肤病提供了新的方法。本文从皮肤种子细胞培养、真皮支架材料和体外构建活性复合皮三个方面对组织工程皮肤的研究进展进行了综述。目前组织工程皮肤在一定程度上克服了原有的皮肤供区不足、免疫排斥、传播疾病等各种问题。新的种子细胞和支架材料逐渐成熟,并逐渐应用于临床治疗;在种子细胞和真皮替代物基础上发展起来的复合皮肤可以更快速的促进缺损皮肤的愈合,但与在体皮肤比较尚有差距。组织工程皮肤是理想的皮肤替代物,具有良好的发展前景,未来的研究应该着眼于模仿机体皮肤的生理结构和功能,使愈合后的皮肤与在体皮肤融为一体。     

组织工程皮肤研究现状

组织工程皮肤是通过培养功能细胞,将其与细胞外基质及支架材料互相作用,制成的具有生物活性的人工皮肤替代物。组织工程皮肤的发展为修复皮肤创面,重建皮肤功能,治疗皮肤病提供了新的方法。本文从皮肤种子细胞培养、真皮支架材料和体外构建活性复合皮三个方面对组织工程皮肤的研究进展进行了综述。目前组织工程皮肤在一定程度上克服了原有的皮肤供区不足、免疫排斥、传播疾病等各种问题。新的种子细胞和支架材料逐渐成熟,并逐渐应用于临床治疗;在种子细胞和真皮替代物基础上发展起来的复合皮肤可以更快速的促进缺损皮肤的愈合,但与在体皮肤比较尚有差距。组织工程皮肤是理想的皮肤替代物,具有良好的发展前景,未来的研究应该着眼于模仿机体皮肤的生理结构和功能,使愈合后的皮肤与在体皮肤融为一体。     

植入了骨修复材料的小型猪腰椎椎体不脱钙病理组织切片制备方法

摘要 目的：建立植入了骨修复材料小型猪腰椎椎体骨组织标本的不脱钙病理组织切片制备方法。方法：将含骨修复材料的腰椎椎体骨组织标本进行分割暴露组织切面,梯度浓度乙醇脱水后经Technovit 7200 VLC光聚树脂浸润,经黄蓝光共同辐照进行光聚合包埋,借助硬组织病理切磨系统制备含骨修复材料不脱钙病理组织切片。结果：结果显示通过上述方法制备的病理组织切片,经苏木精-伊红（HE）染色及甲苯胺蓝染色后光学显微镜下观察能较好地显示骨的各种组织细胞结构,可清晰的观察到骨小梁的走向及连接情况。结论：研究建立了含骨修复材料骨组织标本病理组织切片制备方法,实现了含骨修复材料不脱钙骨组织病理切片的制备,经病理染色后实现了带植入物的组织学观察,为生物材料及医疗器械动物试验研究提供了新的病理检测手段及组织学评价途径。     

吻合皮下静脉的带蒂皮瓣修复四肢皮肤软组织缺损的效果分析

摘要 目的：探讨与分析吻合皮下静脉的带蒂皮瓣修复四肢皮肤软组织缺损的效果。方法：选择2018年12月到2021年12月在本院创伤造成的四肢皮肤软组织缺损60例患者作为研究对象,将其随机分为吻合皮下静脉带蒂皮瓣组与传统带蒂皮瓣组各30例。吻合皮下静脉带蒂皮瓣组给予吻合皮下静脉的带蒂皮瓣修复治疗,传统带蒂皮瓣组给予常规直接覆盖创面修复治疗。结果：所有患者都顺利完成手术,吻合皮下静脉带蒂皮瓣组围手术指标时间均较传统带蒂皮瓣组少（P<0.05）。吻合皮下静脉带蒂皮瓣组术后3个月的总有效率为96.7 %,高于传统带蒂皮瓣组的76.7 %（P<0.05）。吻合皮下静脉带蒂皮瓣组术后3个月的并发症发生率较传统带蒂皮瓣组低（P<0.05）。吻合皮下静脉带蒂皮瓣组术后6个月的感觉功能恢复情况好于传统带蒂皮瓣组（P<0.05）。结论：吻合皮下静脉的带蒂皮瓣能促进患者的创面愈合,提高治疗效果,减少并发症,加快恢复患者的四肢皮肤软组织缺损。     

丝素蛋白在电纺丝法构建组织工程支架中的应用进展

丝素蛋白是天然高分子纤维蛋白,具有良好的物理和机械力学性能及生物相容性,因而在组织工程领域有着广阔的应用前景。文中对丝素蛋白的化学组成、分子结构特点、提取方法以及利用静电纺丝技术在组织工程化支架构建中的应用作了概述。总结了丝素蛋白在用于组织工程材料上的性能和优势以及在人工血管、皮肤、骨组织等工程化支架方面的应用情况,探讨了丝素蛋白支架对细胞在其上生长、增殖和功能的影响,同时对丝素蛋白在组织工程化食道支架及其他再生医学上的应用前景进行了展望。     

γ-PGA/HEMA/PEG聚合物晶胶支架修复兔眼眶骨折缺损的实验研究

目的 近年来,眶骨骨折发生率逐年增加,其治疗关键旨在修复缺损的眶骨,聚（γ-谷氨酸）/2-羟乙基甲基丙烯酸酯/聚（乙二醇）（γ-PGA/HEMA/PEG）聚合物晶胶是一种具有互连多孔结构的新型支架材料,研究旨在检验其在眼眶骨折缺损修复中的骨修复效果。方法 采用低温凝胶技术制备了γ-PGA/HEMA/PEG聚合物晶胶。制备了兔的眼眶骨缺损模型,根据植入支架材料的不同分为3组,空白对照组、聚合物晶胶组（Gel组）、矿化聚合物晶胶组（M-gel组）。植入后8周和16周标本取材进行大体观察,通过影像学和组织学检查观察其血管生成和成骨效果。结果 影像学检查结果表明,支架材料能有效促进眶骨缺损的修复,缺损区被骨组织完全替代。组织学结果表明,支架材料可以增加Runt相关转录因子2（Runx-2）、碱性磷酸酶（ALP）、骨桥蛋白（OPN）和血小板内皮细胞黏附分子1（CD31）的表达,这表明支架材料植入后血管生成和成骨能力增强。结论 矿化聚合物晶胶是一种良好的眼眶骨折缺损修复的支架材料。     

聚苹果酸及其衍生物的制备与应用研究进展

摘要：天然和合成聚合物因优良的特性引起了越来越多研究者的兴趣,并已被广泛用于人类的日常生活中。聚苹果酸（Polymalic acid,PMLA）一种天然的高分子聚酯材料,具有良好的生物相容性和完全生物降解性,其衍生物同样具有优异的生物学性能,被广泛应用于众多领域中。本文就聚苹果酸及其衍生物的结构、性质和合成方法进行了概述,并全面总结了其在制药和其他领域的应用研究现状,最后对未来发展方向进行了展望。     

重建组织工程化皮肤生物学功能研究

皮肤是人体最大的器官,易受到内外异常因素的损害而导致各种创伤。组织工程化皮肤为促进皮肤创伤修复起了很大的作用,但由于组织工程化皮肤只具备生理皮肤的相似结构,不具备其正常生物学功能,不能实现患者对皮肤创伤实现“完美愈合”的理想,难以广泛应用于临床。因此,构建具有生物学功能的理想人工皮肤是皮肤组织工程研究的重要课题。总结了当前组织工程化皮肤的缺陷,提出构建具有生物学功能人工皮肤的策略。     

ADSCs联合Exendin-4治疗糖尿病大鼠创面愈合的机制研究

摘要 目的：探究ADSCs联合Exendin-4治疗糖尿病大鼠创面愈合的效果及可能机制。方法：通过高脂饲料喂养和腹腔注射链脲佐菌素（STZ,45 mg/kg）建立糖尿病SD大鼠模型。使用直径1 cm的皮肤打孔活检器在大鼠背部制作创面。将72只建模成功的大鼠随机分为糖尿病组、ADSCs组、Exendin-4组和ADSCs+Exendin-4组,每组18只。未建模的20只大鼠作为对照组。皮肤创伤后1天,按照指定给药方案进行给药,每天给药1次,共14天。检测治疗后大鼠的血糖、创面愈合率、微血管密度、创面组织学改变和血管生成因子（VEGF-A、VEGFR-2、PDGF-BB、PDGFR-β和HIF-1α）的蛋白表达水平。另外,将HUVEC细胞分为对照组、高糖组、ADSCs组、Exendin-4组和ADSCs+Exendin-4组,并对各组细胞进行相应的处理。检测了ADSCs和Exendin-4对缺氧和高糖培养的HUVEC的增殖、迁移和血管生成的影响。结果：ADSCs和/或Exendin-4治疗组大鼠的血糖水平与糖尿病组无显著差异（P>0.05）。与单独治疗组相比,ADSCs+Exendin-4组的创面愈合率、微血管密度和创面组织中VEGF-A、VEGFR-2、PDGF-BB、PDGFR-β和HIF-1α的蛋白表达水平显著升高（P<0.05）。与单独治疗组的HUVEC相比,ADSCs+Exendin-4组的HUVEC的增殖、迁移和血管生成能力显著提高,并且血管生成因子的表达水平明显上调（P<0.05）。结论：对糖尿病大鼠创面组织局部施用ADSCs和Exendin-4可明显促进创面愈合。ADSCs和Exendin-4通过促进内皮细胞的增殖、迁移及血管生成因子的分泌来促进血管生成和创面愈合。     

响应面分析法优化沙雷氏菌(Serratia sp.) AXJ-M对己烯雌酚的降解

[背景] 环境雌激素已成为目前干扰人类和动物内分泌系统而影响健康和生殖的一类新型环境污染物,利用微生物的降解作用修复被其污染的环境具有重要的现实意义。[目的] 以实验室保藏的一株己烯雌酚（Diethylstilbestrol,DES）降解菌沙雷氏菌（Serratia sp.） AXJ-M为对象,开展其对DES的降解特性及降解条件优化的实验研究。[方法] 利用单因素试验、Plackett-Burman因素筛选、最陡爬坡试验和Box-Behnken设计相结合的方法优化Serratia sp.AXJ-M对DES的降解条件。[结果] （NH₄）₂SO₄、ZnCl₂、胰蛋白胨被分别选做无机氮源、额外金属离子和外加营养物质时,对DES降解有明显的促进作用。利用Plackett-Burman实验确定（NH₄）₂SO₄浓度、DES浓度、pH值为影响菌株AXJ-M降解DES的主要因素。在此基础上,采用最陡爬坡试验和Box-Behnken设计,确定菌株AXJ-M在（NH₄）₂SO₄浓度1.48 g/L、ZnCl₂浓度0.02 g/L、温度30℃、pH 7.19、DES浓度119.5 mg/L、接种量3%（体积分数）下培养7 d,菌株AXJ-M对DES的降解率达到76.89%,较未优化前提高了17.38%。[结论] Serratia sp.AXJ-M具有较高的DES降解能力,该菌可为生物修复受DES或其他人工合成雌激素污染的环境提供优良的微生物资源。     

一种可止血的富血小板血浆壳聚糖/丝素蛋白多孔伤口敷料的制备及性能表征

为了进一步提高伤口敷料的止血性能,文中在生物相容性良好的壳聚糖溶液中引入含有多种生长因子的人源性富血小板血浆(Humanplatelet-richplasma,hPRP),并加入不同体积比例(1∶1、1∶3、3∶1、1∶0)的丝素蛋白溶液以提高材料的多孔性与止血性,通过冷冻干燥法制备不同配比的hPRP-壳聚糖/丝素蛋白敷料,并将纯壳聚糖敷料作为对照组,研究hPRP和丝素蛋白对敷料的止血性能的影响以及丝素蛋白对PRP中生长因子控制释放的影响。结果表明,在壳聚糖敷料中引入hPRP对敷料的止血性有所提高,但对敷料的多孔结构及吸水率无明显改善,若在hPRP-壳聚糖溶液中按照体积比为1∶1的比例加入丝素蛋白溶液,会得到具有较为均匀的多孔结构的敷料,敷料的孔隙率与吸水率分别可达到86.83%±3.84%与1 474%±114%,且该比例的敷料在快速止血性能上表现优异。此外,加入丝素蛋白与壳聚糖比例为1∶1的PRP敷料能有效减少PRP中生长因子在初始阶段的爆裂释放。因此,含hPRP的壳聚糖/丝素蛋白复合敷料有望成为一种能快速止血且能促进伤口愈合的新型伤口敷料。     

Development of advanced antimicrobial and sterilized plasma polypropylene grafted muga (antheraea assama) silk as suture biomaterial

Surface modification of silk fibroin (SF) materials using environmentally friendly and non‐hazardous process to tailor them for specific application as biomaterials has drawn a great deal of interest in the field of biomedical research. To further explore this area of research, in this report, polypropylene (PP) grafted muga (Antheraea assama) SF (PP‐AASF) suture is developed using plasma treatment and plasma graft polymerization process. For this purpose, AASF is first sterilized in argon (Ar) plasma treatment followed by grafting PP onto its surface. AASF is a non‐mulberry variety having superior qualities to mulberry SF and is still unexplored in the context of suture biomaterial. AASF, Ar plasma treated AASF (AASF_Ar) and PP‐AASF are subjected to various characterization techniques for better comparison and the results are attempted to correlate with their observed properties. Excellent mechanical strength, hydrophobicity, antibacterial behavior, and remarkable wound healing activity of PP‐AASF over AASF and AASF_Ar make it a promising candidate for application as sterilized suture biomaterial. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 355–365, 2014.     

Bilayer Amniotic Membrane/Nano-fibrous Fibroin Scaffold Promotes Differentiation Capability of Menstrual Blood Stem Cells into Keratinocyte-Like Cells

The skin provides a dynamic barrier separating and protecting human body from the exterior world, and then immediate repair and rebuilding of the epidermal barrier is crucial after wound and injury. Wound healing without scars and complete regeneration of skin tissue still remain as a clinical challenge. The demand to engineer scaffolds that actively promote regeneration of damaged areas of the skin has been increased. In this study, menstrual blood-derived stem cells (MenSCs) have been induced to differentiate into keratinocytes-like cells in the presence of human foreskin-derived keratinocytes on a bilayer scaffold based on amniotic membrane and silk fibroin. Based on the findings, newly differentiated keratinocytes from MenSCs successfully expressed the keratinocytes specific markers at both mRNA and protein levels judged by real-time PCR and immunostaining techniques, respectively. We could show that the differentiated cells over bilayer composite scaffolds express the keratinocytes specific markers at higher levels when compared with those cultured in conventional 2D culture system. Based on these findings, bilayer amniotic membrane/nano-fibrous fibroin scaffold represents an efficient natural construct with broad applicability to generate keratinocytes from MenSCs for stem cell-based skin wounds healing and regeneration.     

Chemical modification of arginyl residues in silk fibroin: 1. Reaction of 1,2-cyclohexanedione in borate buffer.

Chemical modifications of silk fibroin were attempted in order to add new properties and functions to silk fibroin. The arginyl residue in solubilized silk fibroin was chemically modified with the reaction of 1,2-cyclohexanedione in borate buffer. FT-i.r. and c.d. spectra of the silk fibroin before and after the modification indicated that the fraction of random coil conformation increased with the modification. The chemical stability of the modified silk fibroin membrane was investigated in vitro with phosphate buffer. The modified arginyl residue in the membrane was considerably regenerated with the treatment in phosphate buffer.     

Wound dressings for a proteolytic-rich environment

Wound dressings have experienced continuous and significant changes over the years based on the knowledge of the biochemical events associated with chronic wounds. The development goes from natural materials used to just cover and conceal the wound to interactive materials that can facilitate the healing process, addressing specific issues in non-healing wounds. These new types of dressings often relate with the proteolytic wound environment and the bacteria load to enhance the healing. Recently, the wound dressing research is focusing on the replacement of synthetic polymers by natural protein materials to delivery bioactive agents to the wounds. This article provides an overview on the novel protein-based wound dressings such as silk fibroin keratin and elastin. The improved properties of these dressings, like the release of antibiotics and growth factors, are discussed. The different types of wounds and the effective parameters of healing process will be reviewed.     

Fibroin and Sericin from Bombyx mori Silk Stimulate Cell Migration through Upregulation and Phosphorylation of c-Jun

Wound healing is a biological process directed to the restoration of tissue that has suffered an injury. An important phase of wound healing is the generation of a basal epithelium able to wholly replace the epidermis of the wound. A broad range of products derived from fibroin and sericin from Bombyx mori silk are used to stimulate wound healing. However, so far the molecular mechanism underlying this phenomenon has not been elucidated. The aim of this work was to determine the molecular basis underlying wound healing properties of silk proteins using a cell model. For this purpose, we assayed fibroin and sericin in a wound healing scratch assay using MDA-MB-231 and Mv1Lu cells. Both proteins stimulated cell migration. Furthermore, treatment with sericin and fibroin involved key factors of the wound healing process such as upregulation of c-Jun and c-Jun protein phosphorylation. Moreover, fibroin and sericin stimulated the phosphorylation of ERK 1/2 and JNK 1/2 kinases. All these experiments were done in the presence of specific inhibitors for some of the cell signalling pathways referred above. The obtained results revealed that MEK, JNK and PI3K pathways are involved in fibroin and sericin stimulated cells migration. Inhibition of these three kinases prevented c-Jun upregulation and phosphorylation by fibroin or sericin. Fibroin and sericin were tested in the human keratinocyte cell line, HaCaT, with similar results. Altogether, our results showed that fibroin and sericin initiate cell migration by activating the MEK, JNK and PI3K signalling pathways ending in c-Jun activation.     

Structural studies of Bombyx mori silk fibroin during regeneration from solutions and wet fiber spinning

Regenerated silk fibroin materials show properties dependent on the methods used to process them. The molecular structures of B. mori silk fibroin both in solution and in solid states were studied and compared using X-ray diffraction, FTIR, and (13)C NMR spectroscopy. Some portion of fibroin protein molecules dissolved in formic acid already have a beta-sheet structure, whereas those dissolved in TFA have some helical conformation. Moreover, fibroin molecules were spontaneously assembled into an ordered structure as the acidic solvents were removed from the fibroin-acidic solvent systems. This may be responsible for the improved physical properties of regenerated fibroin materials from acidic solvents. Regenerated fibroin materials have shown poor mechanical properties and brittleness compared to their original form. These problems were technically solved by improving the fiber forming process according to a method reported here. The regenerated fibroin fibers showed much better mechanical properties compared to the native silk fiber and their physical and chemical properties were characterized by X-ray diffraction, solid state (13)C NMR spectroscopy, SinTech tensile testing, and SEM.     

股前外侧穿支皮瓣与胸腹带蒂皮瓣对手外伤组织缺损修复的应用效果及对创面愈合程度的影响

摘要 目的：探讨股前外侧穿支皮瓣与胸腹带蒂皮瓣对手外伤组织缺损修复的应用效果及对创面愈合程度的影响。方法：选取我院2018年12月到2020年12月共收治的119例手外伤组织缺损患者作为研究对象,随机分为2组,分别为对照组（n=59,应用胸腹带蒂皮瓣修复术）和观察组（n=60,应用股前外侧穿支皮瓣修复术）。对比两组患者治疗优良率,对比两组患者治疗前后手部创面面积、创面愈合程度以及组织愈合时间,对比两组患者治疗后的Jamar握力、TAM和DASH评分情况,对比两组患者的皮瓣成活率、皮瓣危象率和血管吻合时间。结果：通过对比两组患者治疗优良率发现,观察组患者优的人数为21例、良为35例,优良率为93.33%,对照组患者优的人数为16例,良为30例,优良率为77.97%,观察组高于对照组（P＜0.05）;治疗后,与对照组相比,观察组患者的手部创面面积、组织愈合时间和DASH评分显著减少,创面愈合程度以及TAM与Jamar握力显著增加（P＜0.05）;通过对比两组患者的皮瓣成活率、术后皮瓣危象率以及血管吻合时间发现,两组患者的术后皮瓣危象率、血管吻合时间对比无明显差异（P＞0.05）,两组患者的术后皮瓣成活率对比差异显著,观察组明显高于对照组（P＜0.05）。结论：对手外伤组织缺损患者应用股前外侧穿支皮瓣与胸腹带蒂皮瓣修复术均具有明显的修复效果,但是应用股前外侧穿支皮瓣能够提升治疗效果,提升患者创面愈合程度减少愈合时间,提升患者手部运动情况,提升术后皮瓣成活率,值得临床应用推广。     

Histatin 1 enhanced the speed and quality of wound healing through regulating the behaviour of fibroblast

ObjectivesHistatin 1(Hst 1) has been proved to promote wound healing. However, there was no specific study on the regulation made by Hst 1 of fibroblasts in the process of wound healing. This research comprehensively studied the regulation of Hst 1 on the function of fibroblasts in the process of wound healing and preliminary mechanism about it.Materials and methodsThe full‐thickness skin wound model was made on the back of C57/BL6 mice. The wound healing, collagen deposition and fibroblast distribution were detected on days 3, 5 and 7 after injury. Fibroblast was cultured in vitro and stimulated with Hst 1, and then, their biological characteristics and functions were detected.ResultsHistatin 1 can effectively promote wound healing, improve collagen deposition during and after healing and increase the number and function of fibroblasts. After healing, the mechanical properties of the skin also improved. In vitro, the migration ability of fibroblasts stimulated by Hst 1 was significantly improved, and the fibroblasts transformed more into myofibroblasts, which improved the function of contraction and collagen secretion. In fibroblasts, mTOR signalling pathway can be activated by Hst 1.ConclusionsHistatin 1 can accelerate wound healing and improve the mechanical properties of healed skin by promoting the function of fibroblasts. The intermolecular mechanisms need to be further studied, and this study provides a direction about mTOR signalling pathway.     

New silk protein: modification of silk protein by gene engineering for production of biomaterials.

The interest in silk fibroin morphology and structure have increased due to its attractiveness for bio-related applications. Silk fibers have been used as sutures for a long time in the surgical field, due to the biocompatibility of silk fibroin fibers with human living tissue. In addition, it has been demonstrated that silk can be used as a substrate for enzyme immobilization in biosensors. A more complete understanding of silk structure would provide the possibility to further exploit silk fibroin for a wide range of new uses, such as the production of oxygen-permeable membranes and biocompatible materials. Silk fibroin-based membranes could be utilized as soft tissue compatible polymers. Baculovirus-mediated transgenesis of the silkworm allows specific alterations in a target sequence. Homologous recombination of a foreign gene downstream from a powerful promoter, such as the fibroin promoter, would allow the constitutive production of a useful protein in the silkworm and the modification of the character of silk protein. A chimeric protein consisted of fibroin and green fluorescent protein was expressed under the control of fibroin in the posterior silk gland and the gene product was spun into the cocoon layer. This technique, gene targeting, will lead to the modification and enhancement of physicochemical properties of silk protein.