人工髓核材料(半晶聚乙烯醇水凝胶弹性体)的研制

研制一种可替代椎间盘髓核并恢复其功能的生物医用材料 ,探讨半晶聚乙烯醇水凝胶弹性体材料临床应用的可行性。聚乙烯醇 (PVA)水溶液在 - 2 0℃下冷冻 6～ 12 h,室温下融化 1～ 2 h,上述过程重复 1～ 3次 ,然后对试样进行真空脱水 ,制得人工髓核材料 (半晶 PVA水凝胶弹性体 )。差示扫描量热法 (DSC)和力学性能试验研究了 PVA水溶液浓度、真空脱水和 γ射线辐照对水凝胶 PVA的结晶度和力学性能的影响     

PVA／PAA水凝胶纤维的电刺激响应性能

以过硫酸胺为引发剂,在PVA水溶液中原位聚合丙烯酸单体,得到的PVA／PAA混合水溶液在凝固浴硫酸胺饱和水溶液中纺丝制备了物理缠结和氢固定网络形式的PVA／PAA水凝胶纤维。该纤维于NaCl溶液中在直流电场作用下具有电流－刺激敏感性,表现为溶胀、收缩、弯曲行为。纤维的弯曲速度和最大弯曲度随电场强度和凝胶网络中PAA含量的增加而增大,随电解质溶液离子强度的变化出现临界最大值。纤维向负极弯曲的过程中,在电场下自由离子和反庆子迁移引起的渗透压主导作用,弯曲过程主要是溶胀弯曲;向正极弯曲过程中,由于电化学反应和电场作用下产生的PH梯度导致凝胶网络构像变化主导作用,弯曲主要是收缩弯曲;弯曲由负极向正极转化过程中,两种机理对弯曲的影响相对平衡。     

聚乙烯醇改性医用壳聚糖微球的制备及其血脂吸附实验

目的：制备性能优良的医用壳聚糖微球，用于吸附血脂。方法：以壳聚糖为原料，液体石蜡为悬浮介质，加入适量的交联剂戊二醛和少量的改性剂聚乙烯醇(PVA)，采用悬浮交联工艺，制备壳聚糖微球，采用动态法进行血脂吸附。结果：加入少量PVA制成的壳聚糖微球更有利于吸附血脂中低密度脂蛋白(LDL)、总胆固醇(TC)、甘油三酯(TG)。结论：加入少量改性剂PVA的壳聚糖微球有望成为性能优良的、能选择性吸附血脂的医用微球。     

子宫动脉栓塞术治疗子宫肌瘤21例临床分析

目的 探讨子宫动脉栓塞术(UAE)治疗子宫肌瘤的疗效。方法 选择21例子宫肌瘤病人，采用Seldinger技术行双侧子宫动脉插管，造影确认后注入PVA栓塞颗粒。结果 UAE治疗3个月后，子宫肌瘤病人的临床症状明显缓解，月经恢复正常，肌瘤体积缩小(P＜0．01)。保留了子宫完整的生理功能。结论 UAE治疗子宫肌瘤有其特殊的优越性，为子宫肌瘤病人提供了另一种可选择的治疗方法。     

支气管动脉栓塞治疗大咯血的临床应用

目的探讨支气管栓塞术在治疗大咯血中的临床价值.方法回顾性析海军安庆医院2009年1月至2011年12月收治的经内科治疗无效的咯血患者29例,在选择性支气管动脉造影下,以聚乙烯醇颗粒或明胶海绵行栓塞治疗,并对术后临床疗效和不良反应进行观察.结果术后治疗总有效率达96.6%,治愈率为79.3%,未见明显的不良反应,术后平均随访5.6个月(3～12个月),未见复发病例.结论支气管栓塞术治疗大咯血具有创伤小、操作简单、疗效可靠、起效快等特点,值得临床推广.     

Cell-compatible properties of calcium carbonates and hydroxyapatite deposited on ultrathin poly(vinyl alcohol)-coated polyethylene films

Poly(vinyl alcohol) (PVA) was coated onto polyethylene (PE) films by a repetitive adsorption and drying process, and then the PVA-coated PE films were alternately immersed into aqueous solutions of Ca²⁺ and CO^2- ₃ ions (alternate soaking cycles), to deposit calcium carbonate (CaCO₃) onto the films. The PVA coating was essential for the CaCO₃ deposition. The amount of CaCO₃ deposited increased with an increasing number of cycles. Scanning electron microscopic observations and attenuated total reflection spectra revealed the presence of both calcite and aragonite as the crystal structures of CaCO₃ on the film. L929 fibroblast cells adhered and proliferated on these CaCO₃-deposited PE films, as well as the hydroxyapatite-coated PE films previously prepared. It was found that the PVAcoating and the subsequent deposition of calcium salts on certain films facilitated cell compatibility.     

Plasma protein adsorption pattern and tissue-implant reaction of poly(vinyl alcohol)/carboxymethyl-chitosan blend films

Various poly(vinyl alcohol)/carboxymethyl-chitosan (PVA/CMCS) blend films were prepared by a mechanical blending method and characterized by SEM for their surface and cross-section morphologies. It indicated that blending high CMCS content in PVA plastic led to a rough surface and loose structure. Bovine serum albumin (BSA) and bovine fibrinogen (BFG) were chosen as representative plasma proteins to carry out adsorption tests. Equilibrium adsorption amount of proteins onto the blends decreased with the increase of CMCS content in film matrix, and BSA was more easily adsorbed onto the films than BFG in the same conditions. The blend films also exhibited different trends for BSA and BFG adsorption when pH of the media changed, but maximum adsorption approximately occurred at the isoelectric point of proteins. Moreover, increasing the ionic strength would always decrease the adsorptions of protein onto the films. In animal experiments, it was found that incorporation of CMCS and PVA gave a lower tissue reaction than pure PVA films when they were subcutaneously implanted in Wistar rats. After two weeks subcutaneous implantation, surfaces of PVA became wrinkled and cracked; however, the blend implants exhibited a alveolate porous microstructure.     

Vascularization into a porous sponge by sustained release of basic fibroblast growth factor

Vascularization into a poly(vinyl alcohol) (PVA) sponge was investigated using basic fibroblast growth factor (bFGF). This growth factor was impregnated into biodegradable gelatin microspheres for its sustained release and then the bFGF-containing microspheres or free bFGF were incorporated into PVA sponges. Following subcutaneous implantation into the back of mice, the bFGF-containing gelatin microspheres induced vascularization in and around the sponge to a significantly greater extent than that of free bFGF from 3 days after implantation. Significant ingrowth of fibrous tissue into the sponge was also observed when bFGF-containing microspheres were added to the sponge in contrast to free bFGF. Tissue ingrowth occurred into the deeper portion of the sponge over time while it accompanied formation of new capillaries. Empty gelatin microspheres had no effect on vascularization and the level of fibrous tissue ingrowth into the sponge was similar to that of the control group. It was concluded that incorporation of gelatin microspheres containing bFGF into the PVA sponge was effective in prevascularization of the sponge pores.