NVP-HEMA角膜接触镜材料的透氧性能

以过氧化二苯甲酰(BPO)为引发剂，N-乙烯基吡咯烷酮(NVP)和甲基丙烯酸β-羟乙酯(HEMA)在一定温度下共聚得水凝胶，可作为软性角膜接触镜材料．实验发现，随NVP含量的增大，水凝胶的含水量越大，透氧性增大，水凝胶材料的透氧率(Dk／L)的倒数与其厚度成正比．并自行设计了一套角膜接触镜材料透氧性能的测试装置、     

CS/PMA30水凝胶的制备及其对中性红控释性能的研究

将聚阳离子壳聚糖(CS)与聚阴离子甲基丙烯酰氧乙基磷酰胆碱-甲基丙烯酸二元共聚物(poly(MPC-co-MA),PMA30)进行静电复合,制备CS/PMA30聚离子水凝胶,并用红外(IR)、扫描电镜(SEM)分别对其特征官能团、表面形貌进行表征。然后,以中性红为模型药物对CS/PMA30水凝胶的控释性能进行研究。结果表明,CS/PMA30体系是通过静电作用形成的物理交联水凝胶,对模型药物中性红具有明显的控释性和pH值响应性。该水凝胶具有良好生物相容性有望在药物控释、组织工程等领域具有巨大的应用前景。该研究为进一步提高水凝胶的生物相容性提供了一个新的途径。     

蛋白质在水凝胶角膜接触镜上的吸附及对膜渗透性能的影响

以牛血清白蛋白(BSA)为模型蛋白,通过紫外分光光度法测定了BSA在共聚物水凝胶膜材料上的吸附量．研究了泪液中蛋白质在甲基丙烯酸-β-羟乙酯和N-乙烯基吡咯烷酮(HEMA—NVP)亲水性共聚物水凝胶的吸附情况．结果表明,蛋白质的吸附量随着吸附时间的增长而增大,4天基本达到吸附平衡．蛋白质在水凝胶上的吸附量随着水凝胶的平衡含水量增大而增大,吸附的蛋白质降低了水凝胶的离子通透性和透氧性．     

水凝胶角膜接触镜材料研究进展

以角膜接触镜材料的基本要求为出发点,在相关文献和专利的基础上综述了目前软性亲水的水凝胶角膜接触镜材料的研究进展及发展趋势.特别针对传统型水凝胶角膜接触镜的透氧和均一成分构建的局限,分别重点介绍了高透氧角膜接触镜材料及互穿网络角膜接触镜材料.前者通过引入硅氧烷成分使角膜接触镜的延长配戴成为可能,后者则通过交联互锁的结构实现了材料的均一性和稳定性,从而为角膜接触镜材料在药物释放和治疗用途上的更广泛应用创造了条件.     

改性PVA水凝胶的研制及应用性能研究

以聚乙烯醇(PVA)为主要原料,以壳聚糖(CS)、羧甲基壳聚糖(CMCS)、海藻酸钠(CA)为改性原料,研制一种预防暴露性角膜炎的水凝胶。设计了以主要原料和改性原料混合,通过冷冻-解冻制备复合水凝胶材料,并对其进行含水量、拉伸强度、细菌内毒素、无菌、霉斑等应用性能的表征和研究。结果显示,PVA-CS、PVA-CMCS这2种水凝胶材料有很好的抑菌性,且在低剂量的辐照灭菌下获得无菌材料,而PVA-CMCS水凝胶因无气味将更受青睐,在生物工程学领域有较大的应用潜力。     

NVP/HEMA/RMA共聚水凝胶溶胀性能研究

采用本体聚合法,制备了N-乙烯基吡咯烷酮(NVP)/甲基丙烯酸羟乙酯(HEMA)、NVP/HEMA/EMA(甲基丙烯酸乙酯)和NVP/HEMA/BMA(甲基丙烯酸丁酯)3种不同的共聚水凝胶材料,并用重量法和TG法研究了这3种不同组成水凝胶的溶胀性能.研究结果表明:加入疏水性单体甲基丙烯酸酯类,共聚水凝胶溶胀性能下降,由于EMA与HEMA结构相似,相容性好,其对溶胀性能的影响比BMA的影响小.     

新型PMAA/MWCNT-COOH杂合水凝胶的合成与茶碱释放

通过甲基丙烯酸(MAA)的原位自由基交联聚合反应制备了一系列新型pH敏感的聚甲基丙烯酸/羧基化多壁碳纳米管(PMAA/MWCNT-COOH)杂合水凝胶.利用红外光谱分析仪(FT-IR)、环境扫描电镜(ESEM)、动态粘弹谱仪(MDA)等对杂合水凝胶的结构、形态和力学性能进行表征.结果表明,MWCNT-COOH的引入,使杂合水凝胶的溶胀速率明显高于纯PMAA水凝胶;在溶胀状态下的力学性能测试表明,水凝胶弹性、回复性能等达到了软组织材料的要求.掺杂不同含量的碳纳米管和改变不同pH环境会影响永凝胶的溶胀行为,改变网孔密度和孔径大小,决定在载、释药物过程中起到重要作用.以茶碱为模拟药物对凝胶载、释药物的研究发现,茶碱在肠道环境中释放速率较快,约8h就达到平衡;而在胃部环境中释放较慢,达到平衡需要时间较长.因此,PMAA/MWCNT-COOH杂合水凝胶有望成为一种潜在的控制药物释放型生物医学材料.     

导电复合水凝胶的分类及其在柔性可穿戴设备中的应用

近年来，基于水凝胶的导电材料及其作为柔性可穿戴设备的应用引起了人们的广泛关注。柔性可穿戴设备不仅可以采集人体生理信号用于远程健康监测，还在人机界面、软机器人等方面展示出巨大的应用潜力。导电水凝胶所具有的良好导电性、高延伸性、可调柔韧性、生物兼容性和多重刺激响应性等优点使其成为制备柔性可穿戴设备的理想材料。到目前为止，各种导电材料被广泛用于制作导电复合水凝胶。本文根据导电材料对导电复合水凝胶进行分类，包括离子导电水凝胶(基于盐离子、离子液体、聚电解质等导电物质)、电子导电水凝胶(基于导电聚合物基、碳材料、MXene和金属等导电物质)两大类，并介绍了导电水凝胶在人体运动监测、健康监测、人机界面等柔性可穿戴设备中的应用进展。     

可降解聚天冬氨酸水凝胶的制备与应用研究

以天冬氨酸为原料,合成了聚丁二酰亚胺(PSI);采用氨基封端的聚乙二醇作为交联剂制备出了聚天冬酰胺水凝胶;研究了聚丁二酰亚胺分子量、交联剂分子量以及交联剂的用量等因素对水凝胶溶胀性能的影响,并研究了以甲硝唑为模型药物,在37℃下、pH=4.6的介质中,药物在聚天冬酰胺水凝胶中的控制释放.     

含磷酰胆碱壳聚糖水凝胶的控释性能研究

将聚阳离子壳聚糖(CS)与聚阴离子甲基丙烯酰氧乙基磷酰胆碱-甲基丙烯酸二元共聚物[poly(MPC-coMA),PMA30]通过聚电解质静电复合制备CS/PMA30水凝胶。然后,分别以中性红为模型药物,对CS/PMA30水凝胶的控释性能进行研究。结果表明:该CS/PMA30体系可以有效地控制中性红的释放速率,具有pH响应性及生物相容性,有望在药物控释、组织工程等领域具有巨大的应用前景。     

角膜接触镜材料的应用和研究进展

综述了各种透明高分子材料在角膜接触镜领域的应用及其特性,指出了角膜接触镜材料存在的问题,指明了角膜接触镜材料的发展趋势.     

Determination of oxygen permeability/transmissibility and storage of contact lenses using HPLC with reductive electrochemical detection in combination with a specifically designed sampling unit

A new analytical technique for the determination of oxygen permeability/transmissibility of contact lenses is presented in this paper. The method is based on high performance liquid chromatography (HPLC) with reductive electrochemical detection at -750 mV (vs Ag/AgCl) in combination with a patented sampling chamber that was designed especially for the purpose to determine oxygen at nanomolar levels. Compared to conventional method, the new technique exhibits higher sensitivity, selectivity, and versatility. The method permits the selective determination of oxygen permeability (Dk/L)/transmissibility (Dk) of soft as well as rigid contact lenses with good agreement with the Dk/L (Dk) values reported in the literature. Precision was determined by repeated measurements and yielded relative standard deviations of 3-8% for hydrophile lenses and 5-13% for rigid contact lenses. Because of the extraordinarily high sensitivity of the chromatographic oxygen sensor for the first time, the capability of hydrogel lenses to store oxygen could also be directly monitored.     

Ophthalmic application of poly(HEMA)s containing nanoparticles and dimethylacrylamide

High functional ophthalmic lens materials, poly(HEMA-co-MMA)s were prepared by the copolymerization of HEMA, MMA, MA, EDGMA, and N,N-dimethylacrylamide in the presence of platinum nanoparticles with antimicrobial properties. The hydrophilic monomer N,N-dimethylacrylamide has excellent biocompatibility and oxygen transmissibility. The combination where platinum nanoparticles were added produced a colorless transparent lens. The water contents were in the range of 36.68-44.08% and the refractive index was measured to be in the range of 1.424-1.436. Meanwhile, the oxygen transmissibility ranged from 11.13 x 10(-11) to 17.63 x 10(-11) (cm2/sec) (mlO2/ml x mm Hg) increased with increasing the addition ratio of N,N-dimethylacrylamide. The physical properties measurements of the produced polymers showed that the nanoparticles did not show significant effect on the water content and refractive index of the hydrogel contact lens, but the materials effected to reduce oxygen permeability to a certain extent. The copolymers have excellent oxygen permeability, indicating that the material can be used to fabricate hydrogel contact lenses with high oxygen transmissibility.     

Non-rotational aspherical models of the human optical system

The aim of this work was to define three-dimensional (3D) non-rotational aspherical parametric models for the human cornea and lens using computational geometry and CAD representations. The hyperbolic cosine based function is used for the cornea and a parametric model is used for lens modeling. Data analysis and visualization of 3D non-rotational models were made using the Rhinoceros CAD software and MATLAB software was used for numeric computation. We combined, implemented, and evaluated these models with a 3D ray-tracing in order to fully analyze the human eye model. It was found that 3D non-rotational aspherical models for the human eye could be more accurately modeled and rendered for analysis with finite element method. The objective of this study is to present and analyze mathematical models of the cornea and lens and to highlight the potential of optical applications of the eye models containing astigmatic surfaces, which are more close to the real eye than spherosymmetric eye models.     

Measurement of wave-front aberration in soft contact lenses by use of a Shack-Hartmann wave-front sensor

Lower- and higher-order wave-front aberrations of soft contact lenses were accurately measured with a Shack-Hartmann wave-front sensor. The soft contact lenses were placed in a wet cell filled with lens solution to prevent surface deformation and desiccation during measurements. Aberration measurements of conventional toric and multifocal soft contact lenses and a customized soft contact lens have proved that this method is reliable. A Shack-Hartmann wave-front sensor can be used to assess optical quality of both conventional and customized soft contact lenses and to assist in enhancing lens quality control.     

基于角膜接触镜的眼药缓释水凝胶材料研究进展

常用的眼用药物制剂为滴眼剂或者眼膏剂,具有使用不方便、药物利用效率低、易引起副作用、需频繁施用、影响视力等缺点.采用角膜接触镜缓释的眼用药物制剂可克服这些缺点,因而受到研究人员的重视.综述了基于角膜接触镜、适于缓释眼用药物的poly-HEMA(聚甲基丙烯酸羟乙酯)水凝胶、硅氧烷水凝胶、分子印迹聚合物水凝胶以及含离子配体水凝胶的研究进展,并展望了适于角膜接触镜缓释的眼用制剂的水凝胶材料的发展前景.     

生物医用眼科材料的研究

主要综述了用于眼科的生物医用材料的种类、结构特点及其在眼科中应用的性能,重点介绍了用于人工角膜的光学镜柱材料和支架材料、人工晶状体材料、人工玻璃体材料、人工眼球义眼台和义眼材料、人工泪道和泪液材料、角膜接触镜材料及眼科药物载体材料,展望了生物医用眼科材料的发展方向.     

眼球系统中关键屈光元件的光学模型研究

角膜和晶状体是人眼光学系统中两个关键的屈光元件,为了理解眼内各介质和整个眼球的屈光状态以及视网膜上的成像,有利于眼科临床方面的应用,需要分别对二者进行光学特性模型的分析与研究。根据角膜和晶状体的光学特性,应用光学设计软件Zemax和有关的数学工具,从光学成像角度,分别对角膜和晶状体模型进行研究:基于结合人眼光学模型的角膜双二次曲面模型的建立方法,统计分析了我国人眼实测角膜参数的数据;通过对晶状体折射率分布特点的分析,分别在轴向和径向上进行了综合分析。最后给出了符合我国人眼特点的角膜面型的统计数值,完善了我国人眼角膜光学模型的建立;获得了形式简单且能够表示晶状体折射率分布一般特征的梯度渐变模型表达式。基于收集的我国人眼实测数据的角膜面型模型和晶状体梯度渐变形式的折射率模型,为解决人眼光学系统研究中的关键问题提供了新的方案和思路。