细胞迁移与生物材料

细胞对于外界化学物质的反应是多种多样的,其中一个反应为,迁移或者化学向性,了解其如何发生的,这对于所有器官的正常工作,在异常生长和病理等方面的研究分析至关重要。比如转移癌肿瘤,多细胞器官。最为明显被观察到的方向性迁移也许就是精子游向卵子,     

BSA对生物材料吸附行为的研究

以原子力显微镜为主要研究工具,研究了BSA分子对CoCrMo合金和Al2O3陶瓷的吸附行为,测试了BSA吸附膜的厚度及BSA分子对CoCrMo合金和Al2O3陶瓷的吸附力。     

生物材料的仿生构思

过去30年里,生物材料的研究取得了显著成就,但从临床效果看,其与宿主相互作用亟待改善;哪怕是有些应用于长期埋植体内的替代物,常被机体视为异物,从而启迪人们不要仅着眼于从材料的物化性能方面构思生物材料。文章从蛋白质、糖类和脱氧核糖核酸与材料的关系出发,以细胞作为仿生生物材料的蓝本,从分子和细胞水平讨论了生物特异性材料设计,人工细胞外基质的仿生化途径以及通过材料对细胞编程凋亡的调控等方面的研究思路;试图从生命科学的广度和柔性出发,提出在不同层次和水平上进行仿生,从事生物材料设计,解决生物材料与生物体复杂接口问题,使生物材料向智能化和环境友好化发展。     

生物材料细胞毒性评价研究进展

随着生物材料在医药领域的应用越来越广泛,其临床前的生物安全性评价亦愈加重要。细胞毒性检测是一种体外试验方法,与体内试验方法相比具有简便、快速、重复性好、干扰少、可避免伦理问题等优点,已成为生物材料临床应用前的常规检测项目,在材料的生物相容性评价方面发挥着重要作用。随着现代细胞生物学与分子生物学技术的不断发展,细胞毒性评价试验中出现了一些国内外标准尚未收录的评价新指标与新方法。同时,材料不同的使用目的与使用部位以及新材料的不断涌现,决定了细胞毒性试验方法的多样性。就生物材料相关的细胞毒性试验方法、常用材料细胞毒性评价以及生物材料细胞毒性评价尚存在的问题作一综述,以为相关研究提供参考。     

组织工程用生物材料与系统

当今以工程科学、生命科学原理开发修复、维持或改善组织功能的生物取代物为目标的组织工程正引起先进国家官、产、学各方面的关注，此高新技术不仅能显著提高对疾患的诊治水平，更能形成组织工程产品市场。本文结合１９９６年在加拿大多伦多举行的第５届世界生物材料大会期间举办的组织工程科学展示会为经纬，介绍相关的研究与开发进展。     

纳米生物材料的应用

纳米生物材料是纳米材料和生物材料交叉而成的一个全新领域。纳米尺度的特殊生物效应使得纳米生物材料具有广泛的应用前景。文章按照纳米材料技术在材料领域的最新应用和经典材料的分类方法,对纳米金属生物材料、纳米无机非金属生物材料、纳米高分子生物材料、纳米复合生物材料的研究现状及应用作了综述。     

生物材料细胞粘附肽仿生修饰的研究进展

RGD(Arg-G1y-Asp)短肽序列是一种细胞粘附肽,能被细胞膜上的整合素识别,参与细胞与基质间的粘附.为改善合成生物材料缺乏细胞识别信号的缺点,可将含RGD序列肽经本体或表面修饰引入材料,使材料具有良好的细胞亲和性.综述了采用含RGD肽对各种合成生物材料进行仿生修饰的研究进展.     

胶原模拟多肽对L929细胞粘附的影响

设计合成了3种模拟胶原三螺旋结构或/和整合素识别位点的胶原模拟多肽(CMP),对其进行体外细胞相容性评价,研究其对小鼠成纤维细胞(L929)生长、粘附的影响。实验证实,3种CMP对成纤维细胞生长无明显的细胞毒性反应;3种包被胶原模拟多肽的基底均能在一定程度上促进细胞粘附、生长,具有良好的细胞粘附率和细胞附着形态,其中包含三螺旋结构和整合素识别位点的CMP27具有更好的促粘附效果,细胞粘附数量和形态与胶原接近。初步研究结果证实,胶原三螺旋结构与整合素识别位点共同作用促进L929细胞粘附。因此,CMP可以有效促进细胞粘附,有望作为粘附剂应用于生物医学领域,可为设计以多肽为基础的生物活性材料提供新的研究思路。     

微弧氧化和碱处理对钛的细胞粘附和骨植入行为的影响研究

考察了微弧氧化处理和碱处理对钛表面形貌、涂层成分、羟基磷灰石沉积能力、细胞黏附、骨内植入的影响。结果表明,微弧氧化和碱复合处理后的钛表面TiO2薄膜呈现大量裂缝,表现出表面含大量OH-极性基团的纳米多孔网状结构,此微观结构和组成使材料诱导羟基磷灰石生成能力显著,利于成骨细胞黏附及繁殖,无细胞毒性,细胞兼容性好。通过植入兔股骨4和12周体内动物实验组织学切片表明,材料无毒、无刺激性,与周围组织间有良好的组织相容性,该材料植入动物骨环境中可刺激成骨,具有骨传导作用。相比下,微弧氧化和碱复合处理样品的生物相容性较为优异。     

Tuning of Cell–Biomaterial Anchorage for Tissue Regeneration

Which mechanisms mediate cell attachment to biomaterials? What role does the surface charge or wettability play on cell–material anchorage? What are the currently investigated strategies to modify cell–matrix adherence spatiotemporally? Considering the development of scaffolds made of biocompatible materials to temporarily replace the structure and/or function of the extracellular matrix, focus is given to the analysis of the specific (i.e., cell adhesive peptide sequences) and unspecific (i.e., surface charge, wettability) mechanisms mediating cell‐matrix interactions. Furthermore, because natural tissue regeneration is characterized by the dynamic attachment/detachment of different cell populations, the design of advanced scaffolds for tissue engineering, based in the spatiotemporal tuning of cell–matrix anchorage is discussed.     

蚕丝在生物医用材料领域的应用研究

蚕丝既是优质的天然蛋白纤维,也是优质的高分子蛋白质材料,具有良好的力学性能、生物相容性和可控的生物降解性等。随着生物医用材料领域的不断发展和各学科的交叉融合,蚕丝作为生物医用材料已展示出很强的竞争力,其在该领域的应用潜力已逐渐展现。介绍了蚕丝的构成和特点,总结了蚕丝丝素及丝胶提取的方法,综述了近年来蚕丝及蚕丝蛋白在组织工程、载药、敷料等方面的应用,并客观分析了蚕丝及蚕丝蛋白在这些具体应用过程中所发挥的重要作用及各种蚕丝材料的优缺点,最后就蚕丝在生物医用材料领域的应用前景进行了展望。     

Influence of Biodopants on PEDOT Biomaterial Polymers: Using QCM‐D to Characterize Polymer Interactions with Proteins and Living Cells

Organic conducting polymers (OCPs) are currently the subject of intense research in the area of biomaterials and bioelectronics. Of the OCPs, poly(3,4‐ethylenedioxythiophene) (PEDOT) has attracted significant interest, however there has been little work on investigating the incorporation of biological compounds as the dopant species in the polymer which are aimed at enhancing the biocompatibility and biofunctionality of the material. Here, we incorporate the biological dopants dextran sulphate, chondroitin sulphate, and alginate, into PEDOT polymers and investigate their influence on a suite of physicochemical and electrochemical properties. We employ QCM‐D to study the mass of adsorption and the viscoelastic properties of the important extracellular matrix proteins fibronectin and collagen. Furthermore, we use QCM‐D to study the adhesion of PC12 neural cells to the PEDOT‐biodopant polymers with and without an adsorbed protein conditioning layer. QCM‐D was found to be an excellent tool with which to study conducting polymer–biological interactions, with this report the first time that QCM‐D has been used to study cell interactions with conducting polymer biomaterials.     

Blood-Derived Biomaterial for Catheter-Directed Arterial Embolization

Vascular embolization is a life-saving minimally invasive catheter-based procedure performed to treat bleeding vessels. Through these catheters, numerous metallic coils are often pushed into the bleeding artery to stop the blood flow. While there are numerous drawbacks to coil embolization, physician expertise, availability of these coils, and their costs further limit their use. Here, a novel blood-derived embolic material (BEM) with regenerative properties, that can achieve instant and durable intra-arterial hemostasis regardless of coagulopathy, is developed. In a large animal model of vascular embolization, it is shown that the BEM can be prepared at the point-of-care within 26 min using fresh blood, it can be easily delivered using clinical catheters to embolize renal and iliac arteries, and it can achieve rapid hemostasis in acutely injured vessels. In swine arteries, the BEM increases cellular proliferation, angiogenesis, and connective tissue deposition, suggesting vessel healing and durable vessel occlusion. The BEM has significant advantages over embolic materials used today, making it a promising new tool for embolization.     

生物医用材料的3D打印技术与发展

近年来,由于3D打印技术的迅猛发展,有关3D打印技术的应用受到科学界广泛关注,特别是生物医学领域。3D打印材料的瓶颈制约着3D打印技术的发展,特别是用于生物医学领域的打印材料,只有非常局限的几种,但是研究可打印生物医用材料意义重大,经济效益显著。简述了3D打印技术在生物医学工程上的应用。重点综述了用于3D打印的生物医用材料,主要涉及金属、陶瓷、高聚物、复合材料以及生物墨水等,并且阐述了3D打印材料的发展前景。     

Nitric-Oxide-Releasing Biomaterial Regulation of the Stem Cell Microenvironment in Regenerative Medicine

Stem cell therapy has proven to be an attractive solution for the treatment of degenerative diseases or injury. However, poor cell engraftment and survival within injured tissues limits the successful use of stem cell therapy within the clinical setting. Nitric oxide (NO) is an important signaling molecule involved in various physiological processes. Emerging evidence supports NO's diverse roles in modulating stem cell behavior, including survival, migration, differentiation, and paracrine secretion of proregenerative factors. Thus, there has been a shift in research focus to concentrate efforts on the delivery of therapeutic concentration ranges of NO to the target tissue sites. Combinatory therapies utilizing biomaterials that control NO generation and support stem cell delivery can be holistic and synergistic approaches to significantly improve tissue regeneration. Here, the focus is on recent developments of various therapeutic platforms, engineered to both transport NO and to enhance stem-cell-mediated regeneration of damaged tissues. New and emerging revelations of how the stem cell microenvironment can be regulated by NO-releasing biomaterials are also highlighted.     

In Situ Control of Cell Substrate Microtopographies Using Photolabile Hydrogels

Substratum topography can play a significant role in regulating cellular function and fate. To study cellular responses to biophysical cues, researchers have developed dynamic methods for controlling cell morphology; however, many of these platforms are limited to one transition between two predefined substratum topographies. To afford the user additional control over the presentation of microtopographic cues to cell populations, a photolabile, PEG‐based hydrogel system is presented in which precisely engineered topographic cues can be formed in situ by controlled erosion. Here, the ability to produce precisely engineered static microtopographies in the hydrogel surface is first established. Human mesenchymal stem cell (hMSC) response to topographies with features of subcellular dimensions (～5 to 40 μm) and with various aspect ratios increasing from 1:1 to infinity (e.g., channels) are quantified, and the dynamic nature of the culture system is demonstrated by sequentially presenting a series of topographies through in situ modifications and quantifying reversible changes in cell morphology in response to substratum topographies altered in real time.     

医用镁合金的腐蚀行为与表面改性

对镁及镁合金作为生物材料的可能性和研究进展进行了评述。介绍了镁及镁合金的腐蚀行为与影响其耐蚀性能的主要因素。同时对医用镁及镁合金的几种表面改性技术进行了讨论。