细菌纤维素/聚乙烯醇/聚丙烯酰胺复合水凝胶的性能表征北大核心

背景:随着高分子水凝胶材料应用领域的扩展而对其性能提出了更高要求,研制和开发性能更为优良的高分子水凝胶材料已成为目前的研究热点。目的:比较细菌纤维素改性前后的聚乙烯醇/聚丙烯酰胺水凝胶的力学性能,为其用于伤口敷料提供理论依据。方法:实验利用细菌纤维素为增强材料,采用冷冻-熔融法,在细菌纤维素网络中引入聚乙烯醇/聚丙烯酰胺水凝胶,制备了细菌纤维素/聚乙烯醇/聚丙烯酰胺复合水凝胶,采用红外光谱、扫描电镜、热重分析、力学性能测试等手段对凝胶的结构和性能进行表征。结果与结论:①通过扫描电镜和红外光谱图可以看到聚乙烯醇和聚丙烯酰胺结合到了细菌纤维素上,说明制备出了细菌纤维素/聚乙烯醇/聚丙烯酰胺复合水凝胶;②细菌纤维素增强复合凝胶的热稳定性、拉伸强度明显提高,而断裂伸长率较细菌纤维素增强前下降;③聚丙烯酰胺浓度为1.0%时,复合水凝胶的拉伸强度和断裂伸长率最大分别为331.79 kPa和105.33%,聚乙烯醇浓度为3.5%时,复合水凝胶的断裂伸长率最大为46.25%,而拉伸强度随聚乙烯醇浓度的增加而增加;④结果表明,细菌纤维素的引入明显提高了水凝胶材料的力学性能,增强了其稳定性,该复合水凝胶有望用作伤口敷料。     

人工髓核材料-聚乙烯醇水凝胶/聚乙烯纤维复合物的生物相容性研究*

目的评估人工髓核材料聚乙烯醇水凝胶／聚乙烯纤维复合物的生物相容性。方法根据ISO10993-1标准，采用细胞毒性试验（琼脂扩散法）、皮内刺激试验、Ame’s致突变试验、微核试验和体内植入（360天）试验对聚乙烯醇水凝胶／聚乙烯纤维复合物的生物相容性进行评估。结果聚乙烯醇水凝胶／聚乙烯纤维复合物的细胞毒性评分小于Ⅰ级，细胞生长无明显抑制现象，对皮内无刺激作用，Ames致突变试验为阴性，微核出现率为3．48‰，无致突变反应。体内植入符合植入材料生物学评价要求。结论聚乙烯醇水凝胶／聚乙烯纤维复合物具有良好的生物安全性，是一种无毒、对皮肤及肌肉、椎间隙无刺激作用的生物医用材料，在动物体内不引起排异反应，可应用于临床。     

人工髓核材料-聚乙烯醇水凝胶/聚乙烯纤维复合物的生物相容性研究*

目的评估人工髓核材料聚乙烯醇水凝胶/聚乙烯纤维复合物的生物相容性。方法根据ISO10993-1标准,采用细胞毒性试验(琼脂扩散法)、皮内刺激试验、Ame's致突变试验、微核试验和体内植入(360天)试验对聚乙烯醇水凝胶/聚乙烯纤维复合物的生物相容性进行评估。结果聚乙烯醇水凝胶/聚乙烯纤维复合物的细胞毒性评分小于Ⅰ级,细胞生长无明显抑制现象,对皮内无刺激作用,Ames致突变试验为阴性,微核出现率为3.48‰,无致突变反应。体内植入符合植入材料生物学评价要求。结论聚乙烯醇水凝胶/聚乙烯纤维复合物具有良好的生物安全性,是一种无毒、对皮肤及肌肉、椎间隙无刺激作用的生物医用材料,在动物体内不引起排异反应,可应用于临床。     

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     

聚乙烯醇/羟基磷灰石复合水凝胶软骨植入材料的研究

研究了用于人工关节软骨假体的聚乙烯醇水凝胶和羟基磷灰石复合材料的结构与性能，系统讨论了含水量、羟基磷灰石含量等对其拉伸强度，压缩强度，黏弹性、润滑性等生物力学性能的影响，观察和比较了复合材料的徽观形貌。研究表明羟基磷灰石在聚乙烯醇水凝胶中分散均匀，良好相容，使复合材料的力学强度和润滑性能提高。     

人工髓核材料-聚乙烯醇水凝胶的溶胀性能研究

利用冷冻-解冻法制得聚乙烯醇(PVA)水凝胶弹性体,研究了其用于人工髓核材料的溶胀特性,以及聚乙烯醇浓度、溶胀温度、溶胀体系的pH值对其溶胀性能的影响,采用扫描电镜对其微观形貌进行了观察,并对其溶胀动力学进行了探讨。结果表明,聚乙烯醇水凝胶是一种多孔网状结构,网络孔径大小与水凝胶中聚乙烯醇的含量有关;增加聚乙烯醇的浓度,提高溶胀温度以及溶胀体系的pH值,其平衡溶胀率减小;通过溶胀动力学方程对其溶胀过程进行了描述,水凝胶中聚乙烯醇的含量,试样尺寸以及溶胀体系的pH值,是溶胀速率快慢的重要影响因素。     

聚乙烯醇/丙烯酰胺接枝共聚物水凝胶的制备及表征

背景：交联水凝胶主要是使大分子链形成网状结构,网固交联基质,这样所得的水凝胶力学性能和透明性相对较差。 目的：采用自由基聚合机制制备聚乙烯醇/丙烯酰胺接枝共聚物水凝胶。 方法：以聚乙烯醇分子作为主链,聚乙烯醇分子中羟基为接枝点,共价接入丙烯酰胺单体。考察反应温度、时间、单体用量和引发剂用量对产物接枝率的影响,通过红外光谱表征聚乙烯醇/丙烯酰胺接枝共聚物共聚物的化学结构。 结果与结论：接枝聚合反应最佳反应条件：引发剂浓度0.04 mol/L、丙烯酰胺/聚乙烯醇(侧羟基)摩尔比6∶1、在40 ℃条件下反应4 h。经过FTIR分析,确认丙烯酰胺与聚乙烯醇发生了聚合反应;经过平衡溶胀测试,分析了接枝聚合物与聚乙烯醇的溶胀率随温度的变化关系,进一步证实了接枝聚合反应的发生,验证了接枝聚乙烯醇/丙烯酰胺接枝共聚物具有明显的温敏性能。      

沉淀法原位复合聚乙烯醇(PVA)/羟基磷灰石(HA)水凝胶的结构与性能研究

研究了制备聚乙烯醇(PVA)，羟基磷灰石(HA)复合水凝胶的沉淀法原位复合技术，对该法制备的复合水凝胶的力学强度、结晶性能和微观形貌进行了分析，并与物理共混法加以比较。结果表明，沉淀法原位复合技术可在PVA水凝胶基体中合成得到粒度细，分散好的晶相HA陶瓷微粒，复合后水凝胶的结晶度和拉伸强度比之基体试样均有大幅度提高。     

羟基磷灰石/聚乙烯醇水凝胶的制备与生物活性评价

背景:先前的研究表明,羟基磷灰石/聚乙烯醇水凝胶复合水凝胶(hydroxyapatite/polyvinylalcoholhydrogel,HA/PVA-H)具有较好的机械性能和耐摩擦磨损性能,这说明HA/PVA-H复合材料具有早期承载能力和较好的生物活性。那么HA/PVA-H复合材料能否通过羟基磷灰石粒子与周围骨组织较快地形成活性结合呢?目的:制备羟基磷灰石/聚乙烯醇水凝胶,并对其进行生物学评价。方法:将Ca(OH)2研磨过筛后,配制成一定浓度的悬浮分散液;加入质量分数15%的PVA水溶液中,添加二甲亚砜,最后按Ca/P比1.67:1加入H3PO4的乙醇溶液,制备HA/PVA-H。对试样进行体外模拟体液培养实验,测试浸泡前后SBF浸泡液的变化,并利用扫描电镜、FTIR、XRD对材料的结构进行了表征和分析。结果与结论:扫描电镜观察可知羟基磷灰石/聚乙烯醇水凝胶表面有结晶体形成,经XRD分析确认为弱结晶的羟基磷灰石晶体;浸泡之后浸泡液的pH值与Ca、P离子浓度下降,同时FTIR结果显示试样中的PO43-特征峰得到增强,且有CO32-的特征峰形成。结果提示,羟基磷灰石/聚乙烯醇水凝胶复合材料具有较好的生物活性。     

聚乙烯醇/羟基磷灰石复合水凝胶修复膝关节软骨缺损的组织相容性

背景：将羟基磷灰石与聚乙烯醇水凝胶复合之后应用于软骨缺损修复中,可在软骨连接部位产生良好的生物活性,有效促进骨细胞的生长,提高植入材料的稳定性和生物活性。 目的：观察聚乙烯醇/羟基磷灰石复合水凝胶修复兔膝关节软骨缺损的组织相容性。 方法：取20只新西兰大白兔,随机分为空白对照组(n=6)与实验组(n=14),构建单侧膝关节软骨缺损模型,空白对照组不予以修复,实验组予以聚乙烯醇/羟基磷灰石复合水凝胶修复。术后4,8,12周获取膝关节标本进行大体观察及组织学观察。 结果与结论：空白对照组关节软骨面在术后12周内始终未得到修复,软骨下缺损存在肉芽组织充填现象,组织学也未见明显修复。实验组术后4周可见聚乙烯醇/羟基磷灰石复合水凝胶填充于缺损处,与周围软骨组织之间连接紧密,且存在清晰的界限,未出现细胞长入情况;至12周时,聚乙烯醇/羟基磷灰石复合水凝胶呈白色、半透明状,表面平坦,与周围软骨组织之间存在清晰界限,两者交界面存在软骨细胞大量增殖现象,与周围组织发生紧密结合,二者之间无间隙,底部与软骨下骨紧密连接,并存在骨样组织长入。表明聚乙烯醇羟基磷灰石复合水凝胶修复兔膝关节软骨缺损具有良好的组织相容性。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

CRG/PVA复合水凝胶的3D打印工艺研究

利用生物高分子材料聚乙烯醇（PVA）、卡拉胶（CRG）的物理、生物学性能及其特殊的交联特性,制备一种可用于3D打印的CRG/PVA复合水凝胶生物墨水材料,为后期的工艺研究提供材料基础。构建了一套适合CRG/PVA复合水凝胶挤出打印的3D打印系统,并在此基础上研究和分析了活塞挤出速度、喷头移动速度、打印高度、线间距等工艺参数对水凝胶尺寸精度的影响。当挤出速度为0.3~0.6 mm/s、喷头移动速度为15~20 mm/s、打印高度为0.3~0.6 mm、线间距大于1.4 mm时,CRG/PVA复合水凝胶有很好的打印效果。水凝胶的临界坍塌角度实验显示对三维打印结构设计支撑结构能增大水凝胶的临界坍塌角度,使得大倾斜角度结构能够成功打印。     

Fabrication and characterization of phlorotannins/poly (vinyl alcohol) hydrogel for wound healing application

Abstract

Phlorotannins (PH) derived from brown algae have been shown to have biological effects. However, the application of PH in biomedical materials has not been investigated. Here, we investigated the effects of PH on normal human dermal fibroblast (NHDF) proliferation and fabricated a composite hydrogel consisting PH and poly (vinyl alcohol) (PVA) (PVA/PH) by a freezing-thawing method for wound healing applications. Cell proliferation was significantly higher in the PH-treated (0.01 and 0.02%) cells than in non-treated cells. Based on the mechanical properties, the PVA/PH hydrogel had a significantly increased swelling ratio and ultimate strain compared to the PVA hydrogel, but the ultimate tensile strength and tensile modulus were decreased. Additionally, cell attachment and proliferation on the composites were evaluated using NHDFs. The results showed that after 1 and 5 days, cell attachment and proliferation were significantly increased on the PVA/PH hydrogel compared with that on the PVA hydrogel. The findings from this study suggest that the PVA/PH hydrogel may be a candidate biomedical material for wound healing applications.     

直接心辅装置CRG/PVA复合水凝胶隔离层的制备与性能研究

基于气动肌肉的直接心辅装置近年来成为研究热点,针对该装置,提出一种水凝胶生物材料隔离层,用于避免气动肌肉与心脏直接接触,减小摩擦力与排异反应。首先选取聚乙烯醇(PVA)作为水凝胶隔离层3D打印的前驱体材料,并进行PVA水凝胶的制备;然后针对水凝胶固化时间长无法应用于3D打印的问题,加入卡拉胶(CRG)进行优化,并进行力学以及溶胀性能探究;最后将3D成型技术运用到隔离层的成型过程,并对水凝胶隔离层的摩擦磨损性能进行研究。结果表明,CRG/PVA复合水凝胶材料拉伸断裂应变及应力分别为280%、0.84 MPa,力学性能良好;CRG不仅能缩短水凝胶固化时间,且其含量从1%增加至5%,水凝胶溶胀度提高到3.70;水凝胶隔离层在120个工作周期后表面仅轻微损伤,进一步验证该结构能改善心脏摩擦环境。     

人工软骨（聚乙烯醇水凝胶）与金属基片（或底层骨）的机械——化学连接

聚乙醇水凝胶（PVA－H）具有良好的生物相容性及优良的磨擦学特性,但这种人工软骨材料很难与底层骨连接,本研究首先使水凝胶与金属纤维网实现微观机械嵌锁连接,然后用骨水泥（PMMA）将纤维网面与底层骨（或金属）粘接,这种方法可实现人工软骨与底层骨（或金属）的机械－－化学连接,微观结构分析及力学测试表明界面连接牢固。     

Genipin-crosslinked polyvinyl alcohol/silk fibroin/nano-hydroxyapatite hydrogel for fabrication of artificial cornea scaffolds—a novel approach to corneal tissue engineering

Abstract

Design of artificial corneal scaffolds substitute is crucial for replacement of impaired cornea. In this paper, porous polyvinyl alcohol/silk fibroin/nano-hydroxyapatite (PVA/SF/n-HA) composite hydrogel was prepared via the genipin (GP) cross-linking, the pore diameter of the hydrogel ranged from 8.138?nm and 90.269?nm, and the physical and physiological function of hydrogel were investigated. The resulting hydrogel exhibited favourable physical properties. With the GP content increasing, the structural regularity of PVA/SF/n-HA composite hydrogel was enhanced and the thermal stability was improved. The moisture content was slightly decreased and generally maintained at approximately 70%. The tensile strength was heightened up to 0.64?MPa, while the breaking elongation was decreased slightly. Moreover, the biofunction was investigated. The in vitro degradation test demonstrated that with the addition of GP, the stability of the composite hydrogels in protease XIV solution was promoted and the three-dimensional porosity structure of composite hydrogels was maintained as ever. And the human corneal fibroblasts (HCFs) were employed to examine the cells cytotoxicity of the PVA/SF/n-HA composite hydrogels with different GP content by CCK-8 assay. Based on confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM), HCFs had individually commendable adhesion and proliferation on PVA/n-HA/SF composite hydrogel. HCFs proliferated and grew into the pores of composite hydrogel. The results of biocompatibility experiments of composite hydrogel suggested that it was no acute toxicity, in vitro cytotoxicity was 0 or 1 grade. Overall, results from this paper, PVA/n-HA/SF composite hydrogel was a qualified medical material which conformed to the national standard, could be a promising alternative for artificial cornea scaffold material—a novel approach to corneal tissue engineering.     

掺锶复合PVA/生物活性玻璃水凝胶的制备及其体外软骨修复性能研究

目的研究以聚乙烯醇(PVA)、生物活性玻璃(BG)及氯化锶为主要原料,制备的PVA水凝胶、PVA/生物活性玻璃水凝胶、掺锶复合PVA/生物活性玻璃水凝胶的可降解性能、离子释放性能和促软骨修复性能。方法PVA溶液与BG溶胶凝胶溶液在加热搅拌下生成PB水凝胶,PVA溶液与Sr-BG溶胶凝胶溶液加热搅拌生成PBSr水凝胶,将PB和PB-Sr水凝胶浸泡于磷酸盐缓冲液(PBS)中,研究其体外降解性能、离子释放性能和结构变化。在水凝胶上培养软骨细胞,经细胞增殖能力实验和细胞荧光染色观察细胞增殖情况。结果 PB和PB-Sr水凝胶在PBS溶液中逐渐降解,28 d后PB水凝胶降解率为25%,PB-Sr水凝胶降解率为16%,水凝胶表面均有羟基磷灰石形成。细胞实验结果显示培养7 d后PB-Sr水凝胶的OD值为0.76±0.04,PB水凝胶的OD值为0.52±0.02,均显著高于对照组,PVA水凝胶的OD值0.45±0.04,差异具有统计学意义(0.05)。结论该掺锶复合PVA/生物活性玻璃水凝胶具有良好的降解性能和离子释放性能,能有效促进软骨细胞增殖。     

PVA /HA复合水凝胶力学性能分析及有限元模拟

目的通过实验与有限元模拟对羟基磷灰石(HA)改变聚乙烯醇/羟基磷灰石(PVA/HA)复合水凝胶的力学性能本质及其承载特性进行研究。方法在UMT试验机上进行PVA/HA复合水凝胶的压缩及应力松弛实验。通过模拟与实验结果相结合,研究PVA/HA复合水凝胶的承载特性及HA对其性能的影响。结果随着HA含量的增加,PVA/HA复合水凝胶的压缩模量先增大后减小,而渗透系数先减小后增大;HA含量为3%的PVA/HA复合水凝胶压缩模量最大、渗透系数最小,分别为1.25 MPa和1.59×10-3 mm4.N-1.s-1。PVA/HA复合水凝胶的液体承载比例随着施载时间的增加呈现先增加后减小的非线性变化,加入HA的PVA/HA复合水凝胶的液体承载比例明显增加。应力松弛速率随着HA含量增加呈先上升后下降趋势,下压相同位移HA,含量为3%时,PVA/HA复合水凝胶所能分散的应力更多。结论 PVA/HA复合水凝胶内部的承载特性影响着其力学性能,HA含量为3%时的PVA/HA复合水凝胶力学性能最优,更接近于天然关节软骨的力学性能。     

Poly(vinyl alcohol) hydrogels as soft contact lens material

A new type of soft contact lens was developed from the poly(vinyl alchol) (PVA) hydrogel prepared by a low temperature crystallization technique using a water-dimethyl sulfoxide mixed solvent. The PVA contact lens materials had a water content of 78% and a tensile strength of 50 kg/cm², five times as strong as that of commercial poly(2-hydroxyethyl methacrylate) soft contact lens. The amount of proteins adsorbed to the PVA soft hydrogel material was half to one thirtieth of that of conventional soft contact lenses. Histological and scanning electron microscopic observation of rabbit eyes which had worn the PVA soft contact lens for 12 weeks showed no difference in corneal epithelium and cell arrangement in the corneal epithelium from the non-wearing eyes.     

Development of a complex hydrogel of hyaluronan and PVA embedded with silver nanoparticles and its facile studies on Escherichia coli

Novel nanocomposite hydrogels composed of hyaluronan (HA), poly(vinyl alcohol) (PVA) and silver nanoparticles were prepared by several cycles of freezing and thawing. The nanocomposite was then characterised using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (XRD) and scanning electron microscopy (SEM). The complex hydrogels consisted of semi-interpenetrating network structures, with PVA microcrystallines as junction zones. By increasing the HA content, the crystallinity and melting temperature of the complex hydrogels decreased, whereas the glass transition temperatures of these materials increased because of the steric hindrance of HA and the occurrence of intermolecular interactions through hydrogen bonding between HA and PVA in the complex hydrogels. Swelling studies showed that in comparison with the swelling properties of the cryogels from PVA alone, those of the complex hydrogels can be significantly improved and presented in a pH-sensitive manner. In addition, silver nanoparticles were synthesised through UV-initiated photoreduction with HA functioning as a reducing agent and stabiliser. The silver nanoparticles were then incorporated in situ into the HA/PVA complex hydrogel matrix. The size and morphology of the as-prepared Ag nanoparticles were investigated through ultraviolet–visible light spectroscopy, transmission electron microscopy, XRD and thermogravimetric analysis. The experimental results indicated that silver nanoparticles 20–50?nm in size were uniformly dispersed in the hydrogel matrix. The antibacterial effects of the HA/PVA/Ag nanocomposite hydrogel against Escherichia coli were evaluated. The results show that this nanocomposite hydrogel possesses high antibacterial property and has a potential application as a wound dressing material.