生物活性聚乙烯醇／羟基磷灰石复合水凝胶的结构与性能

本工作研究了聚乙烯醇和羟基磷灰石复合型生物活性水凝胶，探讨了工艺条件和配方对其拉伸强度，压缩强度，粘弹性、润滑性等生物力学性能的影响，观察和比较了复合水凝胶的微观形貌。研究表明聚乙烯醇和羟基磷灰石可形成接近纳米级的均匀分散结构，良好相容，使复合凝胶的力学强度和润滑性能提高，其应力松弛性能更接近天然软骨的粘弹性。     

Ag／PVA复合水凝胶的制备及其性能的研究

通过沉淀法制备Ag／PVA复合水凝胶，对复合水凝胶的微观结构进行了表征，并对其力学性能和抗菌性能进行了研究。结果表明，银微粒可以通过沉淀法均匀分散在水溶性的PVA中，形成Ag／PVA复合水凝胶，并且这种复合水凝胶具有抗菌性能，并改善了PVA水凝胶的力学性能。     

不同条件对PVA/CS复合水凝胶溶胀性能的影响

以聚乙烯醇(PVA)、壳聚糖(CS)为原料,戊二醛为交联剂,制备出PVA/CS复合水凝胶载体材料,改变PVA/CS的质量配比、交联剂含量、pH值和温度,考察了不同条件下对复合水凝胶溶胀性能的影响.结果表明,当PVA/CS质量比为3:1、交联剂体积分数为4%时所合成凝胶的溶胀性能较好;随着温度的升高,溶胀度不断减小;凝胶在酸性条件的溶胀性能远远优于碱性条件的溶胀性能.     

基于多巴胺改性纳米复合水凝胶的制备和性能

分别在酸性和碱性条件下用多巴胺修饰纳米羟基磷灰石制备纳米粒子改性的复合水凝胶并研究其性能,结果表明：多巴胺能在纳米羟基磷灰石表面生成氧化膜,且改性纳米粒子中的苯环与两性离子水凝胶高分子链形成共价键结合。同时,在酸性条件下多巴胺能提高纳米羟基磷灰石的分散性进而提高两性离子水凝胶的热稳定性(323℃才发生分解),也能提高水凝胶的网络结构强度(储能模量为2.7 MPa)和内耗能力(损耗因子为0.041)。而且,酸性纳米复合水凝胶的抗压能力达到11.66 MPa,比纯PSBMA两性离子水凝胶提高了32倍。这表明,酸性纳米复合水凝胶的结构特点和力学性能与天然软骨相似。     

生物活性聚乙烯醇/羟基磷灰石复合水凝胶的结构与性能

本工作研究了聚乙烯醇和羟基磷灰石复合型生物活性水凝胶,探讨了工艺条件和配方对其拉伸强度,压缩强度,粘弹性、润滑性等生物力学性能的影响,观察和比较了复合水凝胶的微观形貌.研究表明聚乙烯醇和羟基磷灰石可形成接近纳米级的均匀分散结构,良好相容,使复合凝胶的力学强度和润滑性能提高,其应力松弛性能更接近天然软骨的粘弹性.     

氧化石墨烯含量对复合水凝胶性能的影响

目的研究氧化石墨烯含量对氧化石墨烯/聚乙烯醇/聚丙烯酸复合水凝胶性能的影响。方法将氧化石墨烯作为物理交联剂,改变氧化石墨烯的相对含量,制备氧化石墨烯/聚乙烯醇/聚丙烯酸复合水凝胶,并分析其结构、热稳定性、力学、平衡溶胀比和弹性恢复能力。结果氧化石墨烯的含氧官能团与聚乙烯醇的-OH、聚丙烯酸的-COOH以氢键结合,增加氧化石墨烯相对含量可使复合水凝胶的热稳定性和力学性能得到増强,平衡溶胀比减小。结论在试验参数范围内,制得的氧化石墨烯/聚乙烯醇/聚丙烯酸复合水凝胶具有优异的热稳定性、力学性能和弹性恢复能力。     

聚乙烯醇/海藻酸钠复合水凝胶的制备及电场响应性能

将聚乙烯醇和海藻酸钠的混合水溶液通过凝固浴凝固,再通过反复冷冻-解冻的方法制备出交联的水凝胶。该水凝胶在NaCl水溶液中加直流电场后表现出溶胀、收缩、弯曲行为。该凝胶的弯曲速度和最大弯曲度随电压及NaCl溶液浓度的增加而增大,最大形变量随凝胶中的海藻酸钠含量的增加而增大。     

Ag/PVA复合水凝胶的制备及其性能的研究

通过沉淀法制备Ag/PVA复合水凝胶,对复合水凝胶的微观结构进行了表征,并对其力学性能和抗菌性能进行了研究.结果表明,银微粒可以通过沉淀法均匀分散在水溶性的PVA中,形成Ag/PVA复合水凝胶,并且这种复合水凝胶具有抗菌性能,并改善了PVA水凝胶的力学性能.     

纳米掺锶羟基磷灰石/聚乙烯醇/明胶复合水凝胶的制备及矿化性能研究

采用化学沉淀法制备纳米纳米掺锶羟基磷灰石(Sr-HAP)粉体,通过物理法工艺加入聚乙烯醇(PVA)和明胶溶液,经反复冷冻-解冻制备纳米掺锶羟基磷灰石/聚乙烯醇/明胶(Sr-HAP/PVA/明胶)复合水凝胶。利用红外光谱、X射线衍射、扫描电镜对产物的结构进行分析,采用模拟体液法对复合凝胶产物的再矿化行为进行分析。结果表明:实验所制备的复合水凝胶组成均一,凝胶内部Sr-HAP分散良好、分布均匀,且含有大量网状结构,符合理想组织工程支架材料高孔隙率的要求。产物在模拟体液中浸泡15d后,经扫描电镜分析发现凝胶表面有沉积物生成,X射线衍射检测表面沉积物含有类似HAP的物质,说明复合凝胶具有诱导性,有望作为软骨或组织修复材料进一步研究。     

新型PVA/CS/SA复合水凝胶的制备与性能

以聚乙烯醇(PVA)、壳聚糖(CS)、海藻酸钠(SA)等天然物料制备PVA/CS/SA复合水凝胶。通过实验推断出不同质量比、不同剂量的交联剂、不同pH、不同反应温度对复合凝胶的作用,结果表明当PVA∶CS∶SA为8∶4∶1时,水凝胶的品貌最优,综合性能达到最佳。红外分析表明,PVA与CS以及SA之间形成了较强的氢键;DSC分析结果表明,PVA/CS/SA复合膜的热稳定性比壳聚糖膜更强。     

沙柳/聚乙烯醇新型水凝胶复合膜的制备及性能研究

采用湿法纺丝合成新型沙柳木粉(SPP)/聚乙烯醇(PVA)水凝胶复合膜(SPPM)。研究凝固浴时间、硫酸浓度对SPPM吸附Hg²⁺吸附量与力学性能的影响。采用扫描电镜(SEM)、比表面积和平均孔径、红外光谱(FT-IR)和X射线衍射(XRD)等手段分析SPPM的结构和吸附机理;采用热重(TG)对SPPM的热性能进行分析。结果表明:凝固浴时间为1h, H₂SO₄浓度为7%时最佳,吸附量为421mg/g。SPPM具有较好的孔道结构,吸附性能良好且可重复利用5次以上,并具有较大的比表面积以及良好的热稳定性。SPPM的Hg²⁺吸附过程符合伪二级动力学模型和Freundlich等温线模型。     

Preparation and in vitro characterization of BC/PVA hydrogel composite for its potential use as artificial cornea biomaterial

In order to investigate the potential use for bacterial cellulose (BC) as a novel artificial cornea replacement, BC/poly(vinyl alcohol) (BC/PVA) hydrogel composites were synthesized by freezing-thaw method. The BC/PVA composites were characterized by UV–Vis spectrophotometer (UV–Vis), X-ray diffraction (XRD), thermogravimetric (TG) analysis, mechanical property tests and scanning electron microscope (SEM) analyses. Our results showed that the resultant BC/PVA composites exhibited desirable properties as artificial cornea replacement biomaterial including high water content, high visible light transmittance and suitable UV absorbance, increased mechanical strength and appropriate thermal properties. Results of this work revealed that the BC/PVA composites exhibited some promising characteristics as artificial cornea composite material and may be improved further for its realistic applications.     

可注射nano HA/PAG/CS复合材料的制备与表征

通过原位聚合法制备了可注射纳米羟基磷灰石/天门冬氨酸-谷氨酸共聚物/硫酸钙复合材料(HA/PAG/CS), 采用FTIR、XRD、SEM对复合材料的组成结构、表面形貌及力学性能进行了表征, 研究了复合材料在模拟体液(SBF)中的降解性能。结果显示: 复合材料无机相羟基磷灰石、硫酸钙与有机相天门冬氨酸-谷氨酸共聚物之间存在化学相互作用, 具有良好的抗压强度; 7周后, 复合材料在SBF中完全降解, 降解方式为表面降解; 在降解过程中, 浸泡液的pH值在6.4~7.4之间变化; 复合材料在SBF中浸泡后, 其表面能够沉积磷灰石, 表明复合材料具有良好的生物活性, 有利于植入体与骨组织形成良好的界面结合。     

硅基HA/Al2O3复合生物涂层的制备与表征

通过磁控溅射沉积、阳极氧化与溶胶-凝胶结合的多步技术在Si(100)表面制备了HA/Al2O3复合生物涂层材料.采用TG-DSC测定了复合涂层中HA外层的烧成温度,采用XRD、FT-IR以及EDS分析了Si(100)基HA/Al2O3复合生物涂层的组成,并借助SEM研究了复合涂层的表面与截面的微观形貌.研究表明,凝胶完全转变为HA外层的最低温度约为550℃,凝胶经600℃处理30min后可在Si(100)-Al2O3基上形成具有一定数量纳米细孔且含有少量CO3的HA外层;A外层嵌入Si(100)基阳极氧化Al2O3多孔层的孔洞中构成HA/Al2O3复合生物涂层.     

Property-based design: optimization and characterization of polyvinyl alcohol (PVA) hydrogel and PVA-matrix composite for artificial cornea

Each approach for artificial cornea design is toward the same goal: to develop a material that best mimics the important properties of natural cornea. Accordingly, the selection and optimization of corneal substitute should be based on their physicochemical properties. In this study, three types of polyvinyl alcohol (PVA) hydrogels with different polymerization degree (PVA1799, PVA2499 and PVA2699) were prepared by freeze-thawing techniques. After characterization in terms of transparency, water content, water contact angle, mechanical property, root-mean-square roughness and protein adsorption behavior, the optimized PVA2499 hydrogel with similar properties of natural cornea was selected as a matrix material for artificial cornea. Based on this, a biomimetic artificial cornea was fabricated with core-and-skirt structure: a transparent PVA hydrogel core, surrounding by a ringed PVA-matrix composite skirt that composed of graphite, Fe-doped nano hydroxyapatite (n-Fe-HA) and PVA hydrogel. Different ratio of graphite/n-Fe-HA can tune the skirt color from dark brown to light brown, which well simulates the iris color of Oriental eyes. Moreover, morphologic and mechanical examination showed that an integrated core-and-skirt artificial cornea was formed from an interpenetrating polymer network, no phase separation appeared on the interface between the core and the skirt.     

OTS-modified HA and its toughening effect on PLLA/HA porous composite

In this paper, hydroxyapatite (HA) particles was modified with long-chain organic silane-Octadecyltrichlorosilane (OTS), and the modified particles were further used for preparing Poly(l-lactic acid) PLLA/HA porous composite. The modified particles were characterized by means of XRD, FTIR, and XPS techniques. Both XPS and FTIR results showed that OTS had been combined with HA, and the formation of P–O–Si bond, a covalent bond, on the HA particle surface was confirmed by XPS. OTS-modified HA particles were used to prepare porous composites by thermally induced phase separation method. The results showed that the composite had an interconnected pore structure with 100–300 μm macropores. With OTS dosage increasing during modification, the mechanical properties of PLLA/OTS-modified HA porous composites increased obviously. These results showed that OTS modification can effectively improve the interface compatibility between HA surface and PLLA.     

海藻酸钙水凝胶/聚乳酸复合材料的制备与性能

通过化学发泡-冷冻干燥-粒子滤出复合法制备聚乳酸(PLLA)大孔支架, 然后在大孔内以海藻酸钠(SA)、碳酸钙、葡萄糖酸内酯(GDL)为原料, 通过原位相转变制备海藻酸钙水凝胶/聚乳酸复合材料(CA/PLLA); 分别利用SEM、压缩强度测试和细胞培养对CA/PLLA支架的形貌、力学性能及生物相容性进行了研究。结果表明: PLLA具有直径小于2 mm、孔道相互连通的孔洞, 且在大孔中能够形成均匀的CA。CA/PLLA复合材料的压缩强度(2.74 MPa)远大于单一的海藻酸钙水凝胶的压缩强度(0.10 MPa)。在CA/PLLA复合支架中, 软骨细胞呈簇状圆形生长状态, 与其在天然软骨陷窝里生长状态一致。这种软硬结合、天然与合成高分子杂化的CA/PLLA复合材料的力学强度和生物相容性同时得到提高, 可进一步作为骨和软骨修复材料研究。