新型可降解聚合物聚乙二醇对苯二甲酸酯/聚对苯二甲酸丁二醇酯的细胞相容性研究

目的：研究新型可降解聚合物聚乙二醇对苯二甲酸酯／聚对苯二甲酸丁二醇酯(PEGT／PBT)的人脐静脉内皮细胞(HUVEC)相容性，对其在组织工程血管中的应用进行探讨。方法：对PEGT／PBT进行细胞毒性评价。观察并检测HUVEC在PEGB／PBT、Ⅰ型胶原改性(Col-)的PEGT／PBT、纤维连接蛋白改性(Fn-)的PEGT／PBT上的粘附和增殖，对细胞在粘附过程中的粘着斑蛋白进行免疫荧光染色观察。结果：PEGT／PBT细胞毒性不大于1级，能支持脐静脉内皮细胞的粘附和增殖。纤维连接蛋白和Ⅰ型胶原处理可促进HLIVEC在PEGT／PBT膜上的增殖，而且纤维连接蛋白可增加HUVEC在PEGT／PBT上20min、2h的粘附率，并促进细胞形成局部粘附结构。结论：新型可降解聚合物PEGT／PBT具有良好的血管细胞相容性，对其在组织工程血管中的应用值得进一步开发研究。     

静电纺丝聚乳酸聚乙醇酸共聚物-丝素-胶原神经导管修复大鼠周围神经缺损

背景：周围神经缺损修复是临床上一大难题,由于自体神经移植有一定的局限性,人工神经修复材料是一种很有前途的选择。 目的：探讨静电纺丝聚乳酸聚乙醇酸共聚物(PLGA)-丝素-胶原纳米神经导管修复大鼠坐骨神经缺损的可能性。 方法：雌性SD大鼠36只,制备约10 mm的坐骨神经缺损,分别采用倒转自体神经、静电纺丝PLGA-丝素-胶原神经导管、单纯PLGA神经导管桥接,术后12周进行大体观察、神经电生理测定、光镜观察、透射电镜观察和图像分析对比,了解神经再生的情况。 结果与结论：静电纺丝法制备成的纳米神经导管管壁疏松多孔,能够模拟细胞外基质的结构。静电纺丝PLGA-丝 素-胶原神经导管组在促进坐骨神经再生、提高再生神经髓鞘化、加速再生神经功能重建等方面均优于单纯PLGA导管组,比自体神经移植组略差。     

Ⅰ型胶原修饰聚乳酸聚乙醇酸微球支架上骨髓间充质干细胞的黏附和成骨分化

背景：组织工程骨成骨功能终末细胞需要骨髓间充质干细胞在体外加以诱导或在体内以基因转染等技术加以诱导。 目的：研究Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球支架上骨髓间充质干细胞黏附和成骨分化的能力。 方法：制备聚乳酸聚乙醇酸微球支架,分离纯化雌性SD大鼠骨髓间充质干细胞。将培养至第3代骨髓间充质干细胞与未经处理的聚乳酸聚乙醇酸微球及Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球共同培养14 d,观察细胞在不同支架表面的黏附生长。 结果：扫描电镜及FDA-PI染色发现,骨髓间充质干细胞可在聚乳酸聚乙醇酸微球支架上生长,而与未修饰的聚乳酸聚乙醇酸微球相比骨髓间充质干细胞更容易在Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球上黏附增殖。Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球有利于骨髓间充质干细胞的黏附、增殖,并且有一定诱导干细胞成骨分化的能力。     

聚羟基丁酸酯-羟基戊酸酯/溶胶-凝胶生物活性玻璃促进牙周组织再生

BACKGROUND: Our previous studies have shown that the poly(hydroxybutyrate- co-hydroxyvalerate) - sol-gel bioactive glass (PHBV-SGBG) has good biocompatibility and promote bone tissue repair, but its specific role in periodontal tissue regeneration has not been investigated. OBJECTIVE: To investigate the periodontal regenerative effects of a PHBV-SGBG scaffold in beagle dogs. METHODS: Alveolar bone defects (5 mm×5 mm) were surgically created bilaterally at the buccal side of the mandibular third and fourth premolars of four beagle dogs. PHBV-SGBG scaffold was randomly filled in the defects as experimental group and nothing was put into the contralateral as control group. Histological and scanning electron microscopy observations, cone-beam CT evaluation and the Ca/P concentration ratio analysis were processed at 2, 4, 8 and 12 weeks after surgery. RESULTS AND CONCLUSION: After surgery, the height of the regenerated tissue increased with time in both groups, and the regenerated tissue height in the experiment group was higher than that in the control group (P < 0.05). At 12 weeks after surgery, the Ca/P concentration ratio of the experiment group was close to that in the normal tissue (P > 0.05), but higher than that of the control group (P < 0.05); the histological observation showed that the regenerated tissue of the experimental group was close to the normal tissue, and the regenerated tissue of the control group tended to be mature, with a small amount of new blood vessels. Under the scanning electron microscope, no scaffold structure was visible in the experimental group with the presence of bone lacuna at 8 weeks after surgery, while in the control group, there was no bone lacuna and obvious osteoblasts; at 12 weeks after surgery, the structure of the regenerated tissue of experimental group was more regular and close to the normal tissue with no remarkable osteoblasts, and in the control group, the regenerated tissue was disordered, with several cavity. These results show that the PHBV-SGBG scaffold can enhance periodontal bone regeneration effectively.      

应力刺激下兔冈上肌腱急性断裂术后腱-骨修复Ⅰ、Ⅲ型胶原的表达变化

目的　研究应力刺激对其腱-骨修复Ⅰ、Ⅲ型胶原蛋白的表达影响,探讨应力刺激在肩袖损伤术后腱-骨修复中的作用。 方法　选取18只成年雄性新西兰白兔,术前随机选取两只白兔处死,以熟悉解剖结构及对照用。余16只白兔随机分为2组: A组（应力刺激组）与B组（非应力刺激组）。A组术后第2周开始训练;B组正常笼养。分别于术后2、4、6、8周训练结束后处死,取材,每次每组各处死两只,行Ⅰ、Ⅲ型胶原蛋白的表达检测。 结果　⑴术后2周,两组胶原染色阳性,但无明显差别;⑵术后4周,两组胶原染色阳性,A组Ⅰ、Ⅲ型胶原染色颜色均较B组深,且稍显均匀,犹以Ⅲ型胶原为明显;⑶术后6周,Ⅰ、Ⅲ型胶原染色阳性分布均较前广泛, A组较B组明显,且胶原纤维排列相对有序;⑷术后8周,A组胶原排列相对更为有序,Ⅰ型胶原染色较Ⅲ型更为均匀分布,Ⅲ型胶原明显减少。 结论　应力刺激能够促进兔冈上肌腱急性断裂术后腱-骨界面胶原合成,从而促进肩袖损伤术后腱-骨修复。     

聚乳酸-羟基乙酸共聚物/Ⅰ型胶原/壳聚糖人工硬脊膜在兔脊髓损伤模型中的应用*☆

背景：自体组织、异体组织、动物来源的硬脊膜替代材料都难达到降低脊髓损伤后致残率与致死率的修复结果。 目的：观察聚乳酸-羟基乙酸共聚物/Ⅰ型胶原/壳聚糖人工硬脊膜修复大白兔脊髓损伤的疗效。 方法：70新西兰大白兔随机分为4组：假手术组(n=10)：单纯切除椎板,不损伤脊髓;模型组(n=20)：脊髓损伤硬脊膜缺损后未进行修复;壳聚糖组(n=20)：脊髓损伤硬脊膜缺损处植入壳聚糖人工硬脊膜;复合膜组(n=20)：脊髓损伤硬脊膜缺损处植入聚乳酸-羟基乙酸共聚物/Ⅰ型胶原/壳聚糖人工复合膜。 结果与结论：脊髓损伤24 h后,壳聚糖组和复合膜组运动功能评分均明显高于模型组(P < 0.01),复合膜组运动功能评分高于壳聚糖组(P < 0.05)。脊髓损伤之后潜伏期均有明显延长,模型组、壳聚糖组、复合膜组潜伏期明显高于假手术组,在6 h各组潜伏期有明显增加,在24 h左右到达高峰,而后开始逐渐下降,脊髓损伤2 d后模型组、壳聚糖组、复合膜组潜伏期差异无显著性意义。各组细胞凋亡率均大于假手术组(P < 0.05),损伤后6,24 h壳聚糖组和复合膜组细胞凋亡率均明显低于模型组(P < 0.05)。结果提示在大白兔脊髓损伤模型中应用聚乳酸-羟基乙酸共聚物/Ⅰ型胶原/壳聚糖人工硬脊膜有利于脊髓损伤恢复。       

Poly(butylene adipate-co-terephthalate) scaffolds: processing,structural characteristics and cellular responses

The aliphatic-aromatic copolyester, poly(butylene adipate-co-terephthalate) (PBAT) combines good mechanical and thermal properties with biodegradation ability. However, until now, researches in its potential medical use remain limited. Only in a few studies blends of PBAT with routinely used biocompatible polymers had been prepared and investigated regarding tissue engineering applications. Therefore, in this study, we decided to determine processability of neat PBAT as a scaffold material for bone tissue by using different fabrication methods i.e. solvent evaporation, electrospinning, solvent casting-particulate leaching (SCPL) and melt molding-particulate leaching. The results of physicochemical characterizations and cell culture studies with MC3T3-E1 preosteoblasts confirmed that neat PBAT has favorable characteristics for bone tissue engineering, however, fabrication method strongly affects the cellular responses. Regarding to the characterizations and cell cultures, PBAT scaffolds produced by SCPL and electrospinning are proposed to be used for bone tissue engineering.     

The effect of mechanical stimulation on the maturation of TDSCs-poly(L-lactide-co-e-caprolactone)/collagen scaffold constructs for tendon tissue engineering

Mechanical stimulation plays an important role in the development and remodeling of tendons. Tendon-derived stem cells (TDSCs) are an attractive cell source for tendon injury and tendon tissue engineering. However, these cells have not yet been fully explored for tendon tissue engineering application, and there is also lack of understanding to the effect of mechanical stimulation on the maturation of TDSCs-scaffold construct for tendon tissue engineering. In this study, we assessed the efficacy of TDSCs in a poly(L-lactide-co-ε-caprolactone)/collagen (P(LLA-CL)/Col) scaffold under mechanical stimulation for tendon tissue engineering both in vitro and in vivo, and evaluated the utility of the transplanted TDSCs-scaffold construct to promote rabbit patellar tendon defect regeneration. TDSCs displayed good proliferation and positive expressed tendon-related extracellular matrix (ECM) genes and proteins under mechanical stimulation in vitro. After implanting into the nude mice, the fluorescence imaging indicated that TDSCs had long-term survival, and the macroscopic evaluation, histology and immunohistochemistry examinations showed high-quality neo-tendon formation under mechanical stimulation in vivo. Furthermore, the histology, immunohistochemistry, collagen content assay and biomechanical testing data indicated that dynamically cultured TDSCs-scaffold construct could significantly contributed to tendon regeneration in a rabbit patellar tendon window defect model. TDSCs have significant potential to be used as seeded cells in the development of tissue-engineered tendons, which can be successfully fabricated through seeding of TDSCs in a P(LLA-CL)/Col scaffold followed by mechanical stimulation.