聚DL-丙交酯/羟基磷灰石(PDLLA/HA)复合材料(I):制备及力学性能

将羟基磷灰石 (HA)与DL 丙交酯 (DL LA)按一定比例混合 ,在辛酸亚锡引发下开环聚合得到HA微粒填充的聚DL 丙交酯 /羟基磷灰石 (PDLLA/HA)复合材料。在一定引发剂浓度下 ,HA的含量越大 ,粒径越小 ,PDLLA的分子量越低。扫描电子显微镜观察HA微粒均匀分布在PDLLA基质中 ,当PDLLA的分子量在 175 0 0 0～ 2 45 0 0 0范围内 ,HA含量 (HAwt %)为 30 %时 ,复合材料的弯曲强度达 90MPa ,剪切强度为 72MPa,模量为 6 .9GPa ,均高于其它体系。HA的引入不仅提高了材料的初始力学强度 ,而且还延缓了PDLLA的降解速度。     

载抗癌药的生物陶瓷人工骨核的研究

1983年我院开展了将庆大霉素掺入国产骨水泥的研究并取得成功。实验证明骨水泥是庆大霉素的良好控释体。但骨水泥不能载不耐高温及脂溶性药物,且释药不全。为此,我们设计了本组实验,以寻求一种新的载药材料和方法。     

RGD多肽接枝聚复合导管桥接神经缺损的实验研究

Objective To investigate the effect of RGD peptide conjugated poly[ LA-(Glc-Lys) ]/βTCP/PLA nerve conduit for bridging peripheral nerve regeneration defect. Methods Forty-five male Wister rots were randomly divided into 3 groups, with 15 rats each. A 10 mm defect was created in the right sciatic nerve. In group A the gap was bridged by PLA tube. In group B RGD peptide conjugated poly[ LA-(Glc-Lys) ]/β-TCP/PLA nerve conduit was used to repair the defect. Autologous nerve graft was done in group C which served as control. Twelve weeks postoperatively nerve regeneration was evaluated by gross observation,electrophysiology, muscle weight and muscle morphometry of triceps surae, and ultrastructure of the regenerating nerve. Results Twelve weeks after the operation, nerve conduction velocity and muscle weight recovery of group B were better than those of group A. The differences were statistically significant( P < 0.05). There was no significant difference between group B and group C ( P > 0. 05). The results of histology and ultrastructure showed that nerve regeneration in group B and group C was significantly superior to that in group A.Conclusion RGD peptide conjugated poly[LA-(Glc-Lys)]/β-TCP/PLA conduit can achieve similar results in repairing sciatic nerve defect to that of autogentic nerve graft. It may be an ideal material to repair nerve defect.     

Macrophages in degradation of collagen/hydroxylapatite(CHA), beta-tricalcium phosphate ceramics (TCP) artificial bone graft. An in vivo study.

The macrophages mediated biodegradation of two biomaterials, collagen / hydroxylapatite (CHA) and beta-tricalcium phosphate ceramics (TCP), was studied in 24 male Kunming mice and 20 male C57BL / 6 mice with histopathologic, histochemical and ultrastructural observation. It was demonstrated that macrophages infiltrated after CHA, TCP were implanted. The macrophages could be differentiated from fibroblasts and the other infiltrated cells for special cellular profile and strong acid phosphatase activity. Morphologically, monocyte macrophages and infused multinuclear giant cell degraded CHA and TCP by phagocytosis and extracellular resorption. The carbonic anhydrase activity of macrophages was demonstrated by histochemical technique. It suggested that macrophages secreted H and accomplished the decalcification of calcium phosphate compound of CHA and TCP. We conclude that macrophages are the main mediating cells which degraded CHA and TCP intracellularly and extracellularly.     

HA/PDLLA复合材料体内引导成骨过程的组织学研究

为获得羟基磷灰石（HA）／外消旋聚乳酸（PDLLA）复合材料体内引导成骨的实验依据，采用HA／PDLLA复合材料和纯PDLLA材料对照组进行骨内植入实验，通过X线和组织学观察，从组织学角度研究了HA／PDLLA复合材料在体内引导成骨的过程和实际愈合效果，并探讨了成骨机制。体内植入实验的组织学观察结果表明HA／PDLLA复合材料具有良好的生物相容性、适度的生物降解性能、一定的生物学活性和骨传导性能。HA／PDLLA复合材料植入机体后，体内的无菌性炎症轻微，新骨形成速率高于纯PDLLA材料。HA微粒的存在可提高复合材料的机械性能，避免材料过早丧失力学强度。     

聚(羟基乙酸-Nε-苄氧羰基-L-赖氨酸-乳酸)的制备及表征

目的：合成一种新型的带有反应活性基团的聚（乳酸-赖氨酸）共聚物,以改善聚乳酸的细胞亲和性。方法：以N^ε-苄氧羰基-L-赖氨酸和溴乙酰溴为起始原料,合成了单体3S-[4-（苄氧羰基氨基）丁基]-吗啉-2,5-二酮,再以辛酸亚锡为催化剂,通过3S-[4-（苄氧羰基氨基）丁基]-吗啉-2,5-二酮与D,L-丙交酯共聚,制备了聚（羟基乙酸-N^ε-苄氧羰基-L-赖氨酸-乳酸）,并用FT-IR,^1H-NMR,^13C-NMR对反应产物进行了表征。结果：FT-IR,^1H-NMR,^13C-NMR谱图表明各步反应产物的生成,根据^1H-NMR谱图中质子峰的积分面积之比得到共聚物中各单体的摩尔分数。结论：N^ε-苄氧羰基-L-赖氨酸被成功引入到聚乳酸主链中,且共聚物中各组分的含量可通过投料比的不同在较大范围内进行调节。     

骨组织工程用聚DL—乳酸多孔三维结构的制备与表征

采用“溶剂浇铸——颗粒滤沥”方法制备了分子量为 3.9× 10 4道尔顿的聚 DL-乳酸 ( PDL LA)多孔支架并对其进行了表征 ,结果表明 ,其孔隙率高达 88% ,其中孔径为 80～ 150 μm的有效孔占 70 % ;SEM结果进一步显示 ,该三维多孔支架的孔呈均匀分布且相互连通 ,适用于骨组织工程     

钛合金人工关节柄烧结复合生物活性玻璃陶瓷涂层的研究

采用两步涂烧法在钛合金表面制备出防组织液渗透,结合强度高,生物相容性好的复合生物活性陶瓷涂层,适合于改善人工髋关节柄部的骨结合特性。     

曲安耐德缓释膜的制备及其在兔眼穿通伤中的应用研究

以曲安奈德(TA)作为模型药物,壳聚糖和明胶作为基体,制备治疗眼穿通伤用的复合药膜(GICS-TA)。溶剂挥发法制膜,采用红外光谱,X-射线衍射、扫描电镜分析药膜的结构与组成,并植入青紫蓝兔眼脉络膜上腔观察其对眼穿通伤治疗效果。TA与载体有良好的相容性,活性完好。药膜与眼组织生物相容性好,药物可持续释放,通过脉络膜到达视网膜和玻璃体内,抑制眼穿通伤术后创伤性炎症和玻璃体增殖反应,治疗效果优于传统给药方式,可望成为治疗眼穿通伤的新方法。     

陶瓷听骨链的研究及临床应用

我们对自行研究的羟基磷酸钙烧结体听骨链(HA-听骨柱)进行了2年的动物实验观察,并根据光镜、电镜所获可靠结果,对51例慢性化脓性中耳炎患者施以听骨链重建术,术后随访长达2年多,语言频域气导稳定平均提高20～30dB(P-型听柱,76.3%),仅1例发生部分脱出,经2次修复完好,效果令人满意。对比文献报道,本研究有3方面显著特点,即:1、实验是在狗身上进行的;2、结合国人解剖特点制成2mm 长之听柱;3、术中使用 ZT 生物胶更有利用成形创面的粘膜作用。