Ⅰ型胶原海绵/血管内皮生长因子缓释系统的初步构建

[目的]研制Ⅰ型胶原(collagen type Ⅰ,CI)海绵/血管内皮生长因子(vascular endothelial growth factor,VEGF)缓释生物支架材料,了解该种材料中的VEGF体外缓释效果.为骨肌腱组织工程寻求一种新型复合支架材料.[方法]从CI海绵自身的力学、孔径、紫外最大吸收光谱、孔隙率、含水率、傅立叶红外光谱及与VEGF的组织相容性等方面研究VEGF胶原缓释系统支架材料的特性,利用生物学方法将VEGF负载于CI,制备具有VEGF缓释效果的复合支架.[结果]CI海绵能够成功的将VEGF包裹起来,可以达到明显的缓释作用,与VEGF有良好的组织相容性.[结论] CI海绵有理想的孔径和合理的生物力学及与VEGF良好的生物学相容性结构性质,VEGF可以从CI - VEGF缓释材料中缓慢释放,有明显的缓释效果,是一种具有良好材料特性的组织工程材料.     

胶原复合支架在血管组织工程中的应用

目的综述胶原与可降解高分子材料复合支架在血管组织工程中的应用,介绍近年来基于胶原材料制备的多层血管支架。方法查阅近年来胶原复合支架作为组织工程血管支架材料的相关文献,并进行综述。结果作为天然血管的结构蛋白之一,胶原因其良好的组织相容性、可降解性以及具有细胞识别信号等特点,广泛应用于血管组织工程。胶原复合高分子材料可制备具生物活性、力学性能良好的血管支架,其中多层血管支架更可在结构和功能上模拟天然血管。结论胶原复合高分子材料是目前血管支架研究的热点,其中多层血管支架已成为研究的新趋势。     

聚二元共聚物多孔支架活性真皮替代物的体外构建

活性皮肤替代物是指含有活细胞成分的皮肤组织工程产品 ,是皮肤组织工程研究的热点。由于人工合成的生物可降解材料具有生物相容性、加工性能良好以及降解速度可控等优点 ,已被广泛用作细胞支架。然而 ,在多孔的人工材料中种植细胞还存在很多问题。本文应用成纤维细胞胶原凝胶 (fibroblastspopulatedcollagenlattice ,FPCL)的制作方法 ,成功地将人成纤维细胞种植于聚二元共聚物 (乙交酯 /丙交酯polylacticacid/ polyglycolicacidcopolymers ,PLGA)多孔真皮支架中 ,体外培养出一种新型的活性真皮替代物。材　料　与　方　法1.胶原和细胞 …     

WO-1生物衍生骨缓释材料抗感染的实验研究

目的　研制具有抗感染作用的WO- 1生物衍生骨缓释材料。　方法　应用 型胶原和同种骨制备胶原生物衍生骨复合材料,将WO- 1吸附于胶原生物衍生骨构建成WO- 1生物衍生骨缓释材料,扫描电镜观察其形貌特征;将3H-四环素( 4 5 .1GBq/ mmol)以WO- 1标准品溶液稀释,吸附于胶原生物衍生骨,测定缓释材料中WO- 1的体外释放;将WO- 1生物衍生骨缓释材料置入接种金黄色葡萄球菌、大肠杆菌和绿脓杆菌的培养基中,检测其体外抑菌能力。将WO- 1生物衍生骨植入2 4只新西兰大白兔桡骨缺损处,术后9、16、2 3及30 d各处死2只兔测定血中WO- 1的浓度,以及材料周围肌肉与骨中的WO- 1的浓度。　结果　WO- 1生物衍生骨复合材料保留了天然骨的三维结构,表面有胶状膜覆盖;在体外释放实验中第1天呈暴发释放,以后呈恒定释放;对金黄色葡萄球菌、大肠杆菌等骨感染的常见致病菌有持久稳定的抑菌能力。体内实验中周围骨组织及肌肉组织中WO- 1在各时间点均保持较高的浓度,组间比较差异无统计学意义( P>0 .0 5 ) ,而动物血中WO- 1浓度较低,与骨及肌肉组织中WO- 1浓度相比,差异有统计学意义( P<0 .0 5 )。　结论　WO- 1生物衍生骨缓释材料具有良好的药物缓释功能及较强的抑菌能力     

脱细胞真皮基质在整形外科领域的研究及应用进展

脱细胞真皮基质（acellular dermal matrix,ADM）是一种新型的组织工程材料,是由人或动物皮肤组织经各种物理和化学方法,去除表皮及真皮层的细胞成分,保留完整的胶原等细胞外基质蛋白和基底膜而制成.也就是说,ADM中没有细胞成分,但包含除细胞之外的几乎所有成分、结构和功能.由于其具有良好的物理、化学和生物学特性,在创伤修复、组织填充和组织再生中已得到广泛应用.移植物的免疫排斥是异体或异种移植和材料应用的最大难题,但是,冷冻干燥后的灭活骨在移植后不会引起宿主的免疫排斥反应,但允许宿主细胞的重塑和新骨形成（FP Kreuz,1951年）.笔者现重点对ADM的基本特性及其在整形外科领域的临床应用综述如下.     

小肠黏膜下层在泌尿系统组织工程中的研究应用

泌尿道创伤、缺损或狭窄的修复与重建是目前临床上比较棘手的问题。因此,研究者一直试图寻找一种理想的修复泌尿道缺损的材料。小肠黏膜下层(smallintestinalsubmucosa,SIS)是一种新型的具有良好生物相容性和促组织再生特性的细胞外基质框架,在一系列动物实验研究中显示了良好的临床应用前景。随着对SIS研究的进一步深入,SIS在泌尿系统组织工程中的应用将更为广泛。     

水凝胶在骨科中的应用

水凝胶是一种新型医用材料,可广泛应用于骨科领域,包括骨与软骨组织工程、皮肤创面愈合等。随着新型水凝胶制备方法的日趋成熟及其应用方法研究的不断深入,水凝胶材料在骨科临床及基础研究领域的应用前景十分广阔。该文就近年来水凝胶在骨组织工程、软骨组织工程及皮肤创面愈合中的应用进展作一综述。     

转化生长因子明胶微球制备及体外缓释研究

目的: 研制转化生长因子β1 (TGFβ1 ) 缓释明胶微球, 探索将微球药物控释系统引入组织工程学领域的可行性。方法: 采用改良的双相乳化冷凝聚合法制备明胶微球, 将其与TGFβ1 复合, 观察微球分散度、粒径及外观形态; 计算微球包封率、载药率及体外释药特性;分别使用缓释微球、诱导液 (含TGFβ1 4. 5ng/ml) 诱导兔骨髓间充质干细胞 (MSCs) 6d, 免疫组化检测Ⅱ型胶原、S 100蛋白表达。结果: 微球大小均匀, 平均直径 ( 15. 1±3. 4 )μ, 载药量为 900ng/g, 包封率为90. 0%, 体外 7d内药物缓释 92%; 缓释微球可持续释放具有生物活性的TGFβ1 诱导MSCs, 6d后细胞Ⅱ型胶原、S 100蛋白免疫组化染色阳性, 而诱导液组Ⅱ型胶原、S 100蛋白免疫组化染色阴性。结论: TGFβ1 明胶微球具有良好的药物缓释功能, 体外可持续诱导MSCs向软骨细胞分化, 维持细胞表型。为软骨组织工程中生长因子能够持续高效发挥作用提供一种新途径。     

介孔氧化硅纳米材料在骨组织工程中的应用

组织工程骨作为一种极具潜力的新型骨移植材料,有效弥补了现今骨修复材料的缺陷。其中介孔氧化硅纳米材料由于具有比表面积大、生物相容性好、可进一步加工修饰等优点,适合骨组织工程对材料的需求,具有较好的应用前景。针对前期已开展的基础科学研究成果,本文综述了介孔氧化硅纳米生物材料的基本特性和其在骨组织工程中的应用优势,并从药物载体和支架成分两个方面综述了其在骨组织工程中的研究现状,其中药物载体方面主要介绍负载药物的种类和负载方法,支架成分方面则将含有介孔氧化硅纳米材料的支架分为无机支架、有机支架和复合支架三类,并标注了各种支架在微观结构、药物释放动力学、力学性质以及所培养细胞的分子学和细胞学行为等一个或多个方面的突出优点。此外,本文还介绍了介孔氧化硅纳米材料在骨粘合剂中的应用,以及金属离子的引入。最后对介孔氧化硅纳米生物材料在骨组织工程领域的发展方向提出了设想。     

改良脱细胞异种真皮的制备与动物埋藏实验

目的:研制一种新型异种人工真皮。方法:应用鼠尾胶原和异种(猪)脱细胞真皮复合制备成新型复合真皮,将复合真皮与交联型脱细胞真皮分别埋藏于Balb/C小白鼠皮下,观察新型材料的组织相容性及促胶原代谢能力。结果:所有试验小鼠在早期均有毛发脱失现象,交联型真皮组持续时间长并伴有肉芽组织形成。4周后,新型复合真皮显示组织结构致密有序,降解时间更长;组织相容性及促自体胶原代谢能力均较交联型真皮更为优越。结论:新型材料具有更好的组织相容性和更强的促胶原代谢能力,是良好的皮肤组织工程支架材料。     

右旋糖酐基水凝胶药物控释体系的应用研究

目的介绍右旋糖酐基水凝胶在药物缓／控释和组织工程领域中应用的研究概况。方法广泛查阅近年来国内外相关文献，进行回顾与综合分析。结果右旋糖酐基水凝胶的应用研究在国际上已取得明显进展，但在国内才刚起步。右旋糖酐基智能水凝胶作为一种崭新的生物材料，已成为缓／控释给药和组织工程研究的热点之一。结论右旋糖酐基水凝胶是一种新型生物材料，在药物缓／控释和组织工程领域具有广阔的应用前景；通过化学修饰改性后的右旋糖酐基水凝胶可实现“智能”化，具有潜在的研究与应用价值。深入进行其赋性、改性研究并进行相关产品的产业化是未来右旋糖酐基生物材料的研究方向。     

Early performance appraisal of the Omniflow II Vascular Prosthesis as an indicator of long-term function

The search for the ideal vascular prosthesis for below the knee replacement or coronary surgery continues. Long-term explant analysis of a biosynthetic composite vessel, the Omniflow Vascular Prosthesis I, has previously shown sound structural durability. An important determinant in defining durability has been the evaluation of the degree of persistence of the original biological components and the augmentation by new tissue. The development of a panel of specific monoclonal antibodies to collagens, that allow detection of new host collagen among the original collagens of the prosthesis has been a key factor. In the present study, these antibodies have been used to investigate the degree and rate of new collagen tissue infiltration in an improved version of the Omniflow prosthesis. The data show that new collagen types III and VI can be detected as early as 3 months in the adventitial tissue, and that complete tissue augmentation throughout the entire vessel wall is apparent by 6 months after implant. The novel explant analyses serve as a good predictive indication to the in vivo performance of the device and would be useful in rapid monitoring of further modifications to this vessel or to other collagen-based prostheses.     

Biomaterials in functional reconstruction

Recent initiatives in the development of biomaterials for functional reconstruction involve the alloplasts, the biological and the bioengineered biomaterials. Anti-infective alloplastic biomaterials (Foley catheters coated with rifampicin/minocycline bonded to silicone or ciprofloxacin liposome-containing hydrogel) allow a reduction in the rate of bacterial contamination, but the risk of future bacterial resistance is a matter for concern. New generations of biologic collagen-based tissue-matrix grafts are derived from bladder (bladder acellular matrix graft and bladder submucosa collagen matrix), ureter or small intestine (subintestinal submucosa). There are high hopes that these materials may have applications in augmentation cystoplasty. Using tissue engineering (autologous cells expanded in vitro and grafted onto biodegradable matrix), biocompatible malleable penile prostheses have been obtained experimentally. Most of the results obtained with these new biomaterials are exclusively experimental, but they offer great hope for future functional reconstruction of the urinary tract.     

Histologic evaluation of skin-derived and collagen-based substrates implanted in palatal wounds

Tissue shortage complicates the surgery of cleft lip and palate anomalies and the healing of defects on the palate impairs growth of the dento-alveolar complex due to scar tissue formation. Implantation of substitutes into the wound area might overcome this adverse effect. The aim of this study was to compare the tissue response to three collagen-based (collagen type I substrate alone, or collagen coated with elastin or chondroitin-6-sulfate) and two skin-derived substrates (unprocessed dermis and AlloDerm) after implantation into 12 dogs. Histology was performed at 3, 10, and 20 days postsurgery. We showed that all substrates were well tolerated. However, it is unclear whether AlloDerm was rapidly degraded or if it was sequestrated. There was no elastin or collagen present in these wounds. All collagen-based substrates showed good epithelial regeneration, although heparan sulfate (JM 403) was absent. Wounds treated with the collagen-based substrates contained fewer myofibroblasts at 20 days postsurgery and the type III collagen fibers in the immature scar tissue were more randomly oriented than in an untreated wound. In conclusion, palatal wounds with a dermal substrate heal with fewer indications of scar tissue formation and evoke only a mild inflammatory reaction, which is preferred over the tissue reaction in an untreated wound.     

Applications of porcine dermal collagen (ENDURAGen) in facial plastic surgery

The facial plastic and reconstructive surgeon has a variety of options for tissue augmentation and soft tissue support. These options include autologous materials such as fat and cartilages, solid implant materials, and injectable materials. Recently, malleable sheets of collagen-based matrix have become available. This review focuses on the potential applications of acellular collagen matrices and their various applications in rhinoplasty, facial slings for static reanimation, scar revision, soft tissue volume restoration, and periorbital reconstruction.     

Experimental and clinical experience with tissue engineering techniques for urethral reconstruction

Tissue engineering has been proposed as a strategy for urethral reconstruction. This may involve matrices alone, wherein the body's natural ability to regenerate is used to orient or direct new tissue growth, or the use of matrices with cells. Acellular collagen matrices derived from donor bladder submucosa have been used both experimentally and clinically for onlay urethral replacement with good success at our center. If a tubularized urethral repair is needed, the use of cells on the collagen matrix is essential for adequate tissue formation. Tissue engineering techniques are useful for urethral reconstruction.     

Construction of a unidirectionally beating 3-dimensional cardiac muscle construct.

BACKGROUND: Cardiac tissue engineering aims to construct cardiac tissue with characteristics similar to those of the native tissue. Engineered cardiac tissues (ECTs) can be constructed using synthetic scaffold or liquid collagen. We report an initial study using our own newly designed cardiac muscle device to construct heart tissue. We investigated the effects of cell seeding density and collagen quantity on the formation of liquid collagen-based cardiac muscle. METHODS: We obtained cardiac myocytes from neonatal rats mixed with collagen type I and matrix factors cast in circular molds to form circular strands. Cell densities (0.1 x 10(7) to 6 x 10(7)) and collagen quantity (0.3 to 1.0 ml/ECT) were tested. Cell gross morphology, cell orientation, spatial distribution and ultrastructure were evaluated using histologic analyses, confocal laser scanning microscopy and transmission electron microscopy. RESULTS: Histologic analyses of ECTs revealed that cardiac cells reconstituted longitudinally oriented, cardiac bundles with morphologic features characteristic of the native tissue. Confocal and electron microscopy demonstrated that, using optimized cell density and collagen quantity, we made ECTs with characteristic features similar to those of native differentiated myocardium. CONCLUSIONS: ECTs comparable to native cardiac tissue can be engineered under optimized conditions. This construct is a first step in the development of cardiac tissue engineered in vitro, and may be used as a basis for studies of cardiac development, drug testing and tissue replacement therapy.     

椎间盘组织工程支架材料研究进展

目的 综述椎间盘组织工程支架材料及其应用的研究现状。方法 广泛查阅近年来有关椎间盘组织工程支架材料及其应用的文献，进行综述。结果 琼脂糖凝胶、藻酸盐凝胶、Ⅰ型胶原以及聚羟基乙酸和聚乳酸等仍然是目前椎间盘组织工程的主要支架材料，均具有较好的生物相容性。结论 研究开发具有良好性能的支架材料仍是椎间盘组织工程研究的热点和难点之一。