腹壁修补材料的研究及应用进展

巨大腹壁缺损的修补是外科医生经常面临的难题,寻找理想的修补材料以修复缺损至关重要。用于修复腹壁缺损的材料一般分为生物性和非生物性两种。前者的力学性能较好,而后者的生物相容性更佳。目前公认尚没找到一种完全理想的腹壁替代材料.作者对常用生物材料和非生物材料的特性、应用、优缺点等做一综述。     

胶原蛋白作为医用生物材料的应用

胶原蛋白是一类具有活跃生物功能的细胞外间质成分,占人体总蛋白质总量的1/3。胶原蛋白是组织的支持物和填充物,也主动参与了细胞迁移、分化及增殖,并与创伤修复及胚胎发育有关。以胶原蛋白为原料制备的生物替代物(如人造皮肤等)必然大大优于非生物材料的同类产品。目前,大量不同性能及用途的胶原蛋白医用材料不断涌现,有些已结束实验室及动物实验阶段,大批量投入临床应用。     

肿瘤细胞三维培养支架、血管及细胞间的相互作用

背景：肿瘤组织工程通过构建综合的培养模型,充分模拟肿瘤在体内生长的微环境,可以较好地研究肿瘤发生发展的动力学及相关治疗策略。 目的：综述肿瘤工程技术中的肿瘤细胞三维培养。 方法：以“tumor engineering; 3D culture; biological materials; dynamic”为关键词,检索PubMed数据库1992年1月至2013年3月相关文献,纳入有关肿瘤工程、肿瘤细胞三维培养、生物支架材料及肿瘤微环境的相关文章。 结果与结论：三维培养因其可再现组织细胞的体内生长情况,已成为研究肿瘤耐药性、侵袭性和肿瘤微环境的重要平台,在许多领域表现出逐步取代平面培养技术的趋势,为肿瘤研究提供了一个非常接近于体内真实情况的研究平台。近年来,随着肿瘤工程学的发展,多种新型高分子聚合材料被应用于肿瘤细胞的三维立体培养,三维培养技术逐渐成为肿瘤生物学领域研究的热点,其利用各种方法及材料使细胞呈空间立体方式生长,形成类似体内生长环境的生物支撑或基质,建立细胞间及细胞与胞外基质间的相互联系,并形成特定的类似组织样的三维空间结构。生物材料就是种子细胞生长的土壤,在肿瘤工程中起着替代细胞外基质或组织、器官的基质的作用。而随着三维细胞培养技术在肿瘤研究中的广泛应用,其已成为肿瘤耐药、血管形成、细胞间相互作用、信号转导、干细胞等方面研究不可或缺的有力工具。     

结合3D打印技术构建聚己内酯-骨细胞外基质复合支架及体外骨诱导性能

BACKGROUND: Scholars are still looking for ideal bone tissue-engineered scaffolds, and  three-dimensional (3D) printing technology is a novel construction method. In the meanwhile, bone extracellular matrix is becoming a hotspot in osteogenic induction. OBJECTIVE: To construct the polycaprolactone/bone extracellular matrix scaffold using 3D printing technology and co-culture method, and to detect its osteogenic property. METHODS: 216 3D-printed polycaprolactone scaffolds were divided into group A (96 pores, n=72) and group B(48 pores, n=144). Passage 5 bone marrow mesenchymal stem cells from Sprague-Dawley rats were seeded onto the two kinds of polycaprolactone scaffolds, and the group A was used for alizarin red staining and Masson staining, while the group B for collagen and glycosaminoglycan detection at 1, 2 and 3 weeks of incubation. Afterwards, the scaffolds at 1, 2 and 3 weeks of culture were decellularized and labeled as groups AE1, AE2, AE3, BE1, BE2 and BE3. Then passage 5 bone marrow mesenchymal stem cells from Sprague-Dawley rats were seeded onto each scaffold again, and the former three groups underwent alizarin red staining, and the latter three were used for calcium, alkaline phosphatase activity and DNA quantitative analysis at 1, 2 and 3 weeks of culture. RESULTS AND CONCLUSION: Masson staining, glycosaminoglycan and hydroxyproline quantitative analysis showed that the extracellular matrix on the composite scaffold increased with time. Alkaline phosphatase activity revealed that the composite scaffold had a significantly stronger osteogenic differentiation than the normal polycaprolactone scaffold (P < 0.05). Alizarin red staining and calcium quantitative analysis showed that the mineralization of the composite scaffold was more obvious than that of the normal polycaprolactone scaffold (P < 0.05), but the total DNA analysis did not differ significantly between scaffolds. These results suggest that the composite scaffold with extracellular matrix is constructed successfully using the 3D technology and co-culture method and exhibits a better osteoinductivity.     

Preparation and characterization of bionic bone structure chitosan/hydroxyapatite scaffold for bone tissue engineering

Three-dimensional oriented chitosan (CS)/hydroxyapatite (HA) scaffolds were prepared via in situ precipitation method in this research. Scanning electron microscopy (SEM) images indicated that the scaffolds with acicular nano-HA had the spoke-like, multilayer and porous structure. The SEM of osteoblasts which were polygonal or spindle-shaped on the composite scaffolds after seven-day cell culture showed that the cells grew, adhered, and spread well. The results of X-ray powder diffractometer and Fourier transform infrared spectrometer showed that the mineral particles deposited in the scaffold had phase structure similar to natural bone and confirmed that particles were exactly HA. In vitro biocompatibility evaluation indicated the composite scaffolds showed a higher degree of proliferation of MC3T3-E1 cell compared with the pure CS scaffolds and the CS/HA10 scaffold was the highest one. The CS/HA scaffold also had a higher ratio of adhesion and alkaline phosphate activity value of osteoblasts compared with the pure CS scaffold, and the ratio increased with the increase of HA content. The ALP activity value of composite scaffolds was at least six times of the pure CS scaffolds. The results suggested that the composite scaffolds possessed good biocompatibility. The compressive strength of CS/HA15 increased by 33.07% compared with the pure CS scaffold. This novel porous scaffold with three-dimensional oriented structure might have a potential application in bone tissue engineering.     

纳米级多孔负载人骨形成蛋白2基因修饰支架对前成骨细胞株分化的影响

BACKGROUND: Bone tissue transplantation or osteogenic material filling is after used for bone defect repair. To remove autologous bone tissues can lead to additional damage and secondary deformity, therefore, it is extremely urgent to search for a new osteogenic material. OBJECTIVE: To construct the porous β-tricalcium phosphate (β-TCP)/collagen scaffold modified with human bone morphogenetic protein 2 (hBMP2) gene, and to observe its effects on differentiation of MC3T3-E1 cell lines. METHODS: The porous β-TCP/collagen scaffold modified with hBMP2 gene was prepared. Then in vitro culture system of MC3T3-E1 cell lines with composite scaffold was established. There were scaffold and plate groups, and each group was divided into two subgroups according to the different concentrations of plasmid. Samples were collected and observed morphologically by scanning electron microscope and light microscope after complex culture. After 1, 3, 7 and 14 days of induction, calcium nodules were observed through alizarin red staining, the cell cycle was detected by real-time PCR, and expressions of α I-chain collagen type I gene, Osterix and bone sialoprotein were observed. RESULTS AND CONCLUSION: The number of cells adhered, differentated and distributed on the composite scaffold was significantly higher than that of the single scaffold (P < 0.05). Alizarin red staining and real-time PCR detection showed that the osteogenesis ability of MC3T3-E1 cell lines in the scaffold group was stronger than that in the plate group. To conclude, the porous β-TCP/collagen scaffold modified with hBMP2 gene is an appropriate candidate for bone defect repair.     

葛根素在体外对成骨细胞增殖和分化的影响

背景：成骨细胞是骨代谢平衡过程中的关键功能细胞,植物雌激素对成骨细胞的增殖和分化有重要影响,葛根素作为植物雌激素的一种,在体外以较大范围浓度对成骨细胞功能的影响仍少见报道。 目的：观察葛根素在体外对大鼠成骨细胞增殖和分化功能的影响。 方法：取新生Wistar大鼠的颅盖骨,对成骨细胞进行分离、培养、纯化及鉴定。将培养的成骨细胞随机分为对照组、10-3~10-10 mol/L不同浓度葛根素组,观察不同浓度葛根素对体外培养的成骨细胞增殖和碱性磷酸酶活性表达的影响。 结果与结论：细胞经葛根素处理后10-5~10-9 mol/L组成骨细胞增殖活性较对照组明显增加(P < 0.05),第3天增殖最快(P < 0.01),第4天开始下降;诱导第4天,各组碱性磷酸酶活性与对照组相比,差异均有显著性意义(P < 0.01),其中以10-6 mol/L组最显著(P < 0.01)。然而葛根素10-3 mol/L组成骨细胞增殖活性、碱性磷酸酶活性表达较对照组均减少(P < 0.05)。提示葛根素对成骨细胞的影响存在剂量依赖性,并且具有双向性,即在低浓度(10-5~10-8 mol/L)下刺激骨形成;在高浓度(10-3~10-4 mol/L)下抑制骨形成。     

负载木通皂苷D的纳米羟基磷灰石/壳聚糖支架修复骨缺损北大核心

背景:木通皂苷D具有促进成骨细胞的增殖与分化、提高成骨细胞活性与数量、促进基质钙化与骨痂生长等诸多作用,主要被用于治疗骨质疏松与促进骨折愈合,将其应用于骨缺损修复的研究较少见。目的:以纳米羟基磷灰石/壳聚糖支架为载体,将包裹木通皂苷D的缓释微球负载于其中,观察其骨缺损修复作用。方法:采用W/O/W方法制作包裹木通皂苷D的缓释微球,采用冷冻干燥方法制备负载包裹木通皂苷D缓释微球的纳米羟基磷灰石/壳聚糖支架(以下简称缓释支架)与单纯的纳米羟基磷灰石/壳聚糖支架(以下简称空白支架),检测缓释微球与缓释支架的体外释药能力。将小鼠来源前成骨细胞MC3T3-E1分别接种于两种支架上,以单独培养的细胞为对照,分析细胞的黏附、增殖与分化情况。在24只成年新西兰大白兔双侧桡骨中段制造1.5 cm的骨缺损,分别植入空白支架与缓释支架,术后4,12周时进行大体观察、Micro-CT扫描影像学检查及组织学观察。结果与结论:①包裹木通皂苷D的缓释微球与缓释支架均具有缓释作用,其中缓释支架的药物释放速率更加平稳、持久;②CCK-8实验显示,缓释支架上的细胞增殖速率快于空白支架、对照组(P<0.05);扫描电镜下可见,小鼠来源前成骨细胞MC3T3-E1覆盖在两组支架表面,其中缓释支架上的细胞数量要多于空白支架;③培养7,14 d时,缓释支架组的碱性磷酸酶活性、Runx2 mRNA表达高于空白支架组(P<0.05);培养第21天时,缓释支架组的骨桥蛋白、骨钙素蛋白表达量高于空白支架组(P<0.05);④影像学检查与组织学观察结果显示,术后4周时,缓释支架组材料周围可见大量的新生骨,其新生骨量明显多于空白支架组;术后12周时,缓释支架内部也可见大量的新生骨长入,空白支架内部仅见少量的新生骨长入,并且缓释支架组的材料残余明显少于空白支架组(P<0.05);⑤结果表明,负载木通皂苷D缓释微球的纳米羟基磷灰石/壳聚糖支架可提升体外成骨细胞的黏附、增殖与分化能力,提升纳米羟基磷灰石/壳聚糖支架的体内骨诱导能力。     

聚己二酸丁二醇酯-对苯二甲酸丁二醇酯/Ⅰ型胶原取向纤维促进前交叉韧带断裂后腱-骨愈合

背景:材料表面的微/纳米结构对细胞的行为具有调控作用,肌腱组织主要由平行的胶原纤维组成,因此取向纤维结构对腱-骨愈合具有一定的促进作用.目的:探索聚己二酸丁二醇酯-对苯二甲酸丁二醇酯[poly(butylene adipate-co-terephthalate),PBAT]/Ⅰ型胶原取向纤维支架的生物相容性和成骨诱导活...     

重组人促红细胞生成素与骨髓间充质干细胞的迁移及黏附

背景：促红细胞生成素可促进内皮祖细胞的增殖分化并增强其黏附性。 目的：观察重组人促红细胞生成素干预对人骨髓间充质干细胞迁移和黏附能力及相关细胞信号传导通路的影响。 方法：体外培养人骨髓间充质干细胞,使用重组人促红细胞生成素干预第6代人骨髓间充质干细胞。分别用PI3K/Akt通路特异抑制剂Ly294002或p38MAPK通路特异激动剂anisomycin或ERK1/2通路特异抑制剂U0126预处理。 结果与结论：重组人促红细胞生成素可使人骨髓间充质干细胞的PI3K/Akt通路磷酸化水平升高,抑制p38MAPK通路磷酸化水平,对人骨髓间充质干细胞的ERK通路和总Akt、总p38MAPK水平无明显影响。重组人促红细胞生成素作用组中迁移细胞数目显著高于对照组(P < 0.01),黏附细胞数亦明显增加(P < 0.01),PI3K/AKT通路特异抑制剂Ly294002预处理后重组人促红细胞生成素对迁移能力的作用消失,p38MAPK通路特异激动剂anisomycin预处理对两种作用影响均不明显。提示重组人促红细胞生成素具有增强人骨髓间充质干细胞迁移和黏附能力的作用,其增强迁移能力的作用与激活人骨髓间充质干细胞的PI3K/Akt通路有关,但是它对黏附能力的作用与PI3K/Akt和p38MAPK通路均无关。     

新型生物可降解支架材料生物特性及在损伤胆道修复中的应用

BACKGROUND:A variety of factors contribute to biliary injury that is difficult to be repaired. Stent implantation is extensively used for bile duct injury, but either scaffolds made by metal or plastics can lead to certain adverse reactions. OBJECTIVE: To explore the biological characteristics of a novel biodegradable scaffold and its repair effects on bile duct injury. METHODS: The biological characteristics of the novel biodegradable scaffold were detected by fresh bile, and its degradation was observed at different time points. Thirty Bama mini pigs were included and were randomly divided into observation group (n=15) and control group (n=15). After bile duct injury models were prepared, the control group was subjected to the bile duct interrupted suture, while the observation group was subjected to the novel biodegradable scaffold combined with omentum majus. The biological properties of the scaffolds were observed. Hepatic enzymes and serum total bilirubin levels were detected, as well as hematoxylin-eosin staining, Masson staining and immunohistochemistry detection of α-smooth muscle actin were performed. RESULTS AND CONCLUSION: Before and 1, 3 and 6 months after surgery, hepatic enzymes and total bilirubin of two groups were detected, and neither intra-group nor intergroup comparisons had significant differences (P > 0.05). Hematoxylin-eosin staining and Masson staining revealed that inflammatory reactions and fiber hyperplasia at the anastomotic site in the observation group were lighter than those in the control group at different time points after surgery. The α-smooth muscle actin-positive scores in both two groups were in a rise at 1 and 3 months after surgery, and peaked at the 3rd month, and then began to decline. Moreover, the α-smooth muscle actin-positive scores in the observation group were significantly lower than those in the control group at 3 and 6 months after surgery (P < 0.05). These results show that the novel biodegradable scaffold has good biological characteristics and can obtain ideal repair effects in the bile duct injury.     

基底膜蛋白多糖抗体可抑制体外培养成骨细胞合成及分泌转化生长因子β1

背景：到目前为止,基底膜蛋白多糖在骨折愈合的作用机制、调节转化生长因子β1对成骨细胞增殖的作用尚少见报道。 目的：观察基底膜蛋白多糖对胎鼠颅骨成骨细胞合成分泌转化生长因子β1的影响。 方法：分离并培养SD胎鼠颅盖骨成骨样细胞,采用碱性磷酸酶染色法及茜素红染色法鉴定细胞后,随即分对照组、基底膜蛋白多糖阻断组,应用免疫组化和酶联免疫吸附试验检测基底膜蛋白多糖对成骨细胞分泌转化生长因子β1的情况。 结果与结论：与对照组比较,基底膜蛋白多糖阻断组转化生长因子β1浓度降低,差异有显著性意义(P < 0.05)。说明基底膜蛋白多糖抗体能消除其促进成骨细胞分泌合成转化生长因子β1的作用,使转化生长因子β1浓度降低。     

Single-step mineralization of woodpile chitosan scaffolds with improved cell compatibility

A facile and efficient single-step mineralization approach was exploited for achieving nanoscopic hydroxyapatite (HAP) crystal layer in chitosan porous matrix, wherein a mixed water-ethanol solvent was used to control the growth of minerals. The crystallographic structure, morphology, and mechanical properties of the scaffold were analyzed with XRD, FTIR, environmental scanning electric microscopy (ESEM), TEM, and compression tests. The behaviors and responses of MC3T3-E1 pre-osteoblast cells on the scaffolds were studied as well. The results showed that the scaffolds kept woodpile structure with predefined and controlled hierarchical structure after mineralization. The inorganic phase in the mineralized chitosan scaffolds was determined as pure rod-like HAP, which settled densely on the matrix. The compression strength and compressive modulus of the scaffolds increased dramatically to 0.54 ± 0.005 MPa and 5.47 ± 0.65 MPa, respectively. During a culture period of 2 and 3 weeks, cell proliferation and in-growth were observed by phase contrast light microscopy and SEM. The alkaline phosphatase (ALP) activity increased after 1 week. Cell viability and cell proliferation index (PI) obtained higher values than that of the chitosan scaffolds. The novel single-step mineralization approach and the porous hybrid scaffolds would be a promising method for designing hybrid bone graft.