新氧化还原引发体系BMPO—MATS及其在合成医用水凝胶中的初步应用

本文报道亲水性甲基丙烯酸羟乙酯和丙烯酰胺等单体室温快速聚合的氧化还原引发体系:叔丁基过氧化马来酸酯和1,1'一双〔对甲基苯磺酰〕三甲胺。在相同条件下与过氧化苯甲酰和MATS对HEMA的室温引发效果进行了比较。用本引发体系进行了HEMA不同加水量的室温聚合。该材料的各种制品在室温下能浇铸成型,在潮湿环境下使用时能保持其原有尺寸。并用高压液体色谱法测定了聚合物中残余单体含量。本引发体系合成的水凝胶PHEMA在眼科及口腔科进行了初步应用。     

高效液相色谱法对PHEMA液体栓塞材料中单体残留的超痕量分析

应用高效液相色谱法测定了聚甲基丙烯酸-β-羟乙酯(PHEMA)液体栓塞材料中的单体甲基丙烯酸-β-羟乙酯(HEMA)残留量。采用色谱柱Aichrom Bond-1 C18(4.6 mm×250 mm,5μm)进行分离,流动相为乙腈-水(30∶70);检测波长为220 nm;进样量为20μL。单体在质量浓度为0.1~4.0 mg/L的范围,峰面积与单体浓度线性关系良好,相关系数0.9992,检测下限为0.01 mg/L。当试样加标浓度为0.5,2.0,4.0 mg/L时,加标回收率在99.5%~102.0%之间,RSD≤2%。     

壳聚糖与甲基丙烯酸羟乙酯接枝聚合反应的研究

为了改善壳聚糖的亲水性 ,本文用硝酸铈铵为氧化还原引发剂 ,研究了不同聚合反应条件下 ,壳聚糖接枝甲基丙烯酸羟乙酯 (HEMA)的反应规律 ,研究了反应时间、反应温度、引发剂浓度和单体浓度对接枝聚合反应的影响 ,得到了最佳反应条件。用元素分析法和红外光谱对产物进行了表征。用元素分析方法对接枝进行定量分析     

水凝胶HFMC的Ames试验研究(摘要)

水凝胶HFMC是一种以甲基丙烯酸羟乙酯为主要成份,并含有甲基丙烯酸、甲基丙烯酸乙酯的高分子聚合物。该剂具有全面抑制人精子的运动、穿透牛宫颈粘液和穿透去透明带金黄地鼠卵的能力。将水凝胶注入雄性动物的     

异氰酸酯法在聚氨酯表面接枝 聚甲基丙烯酸羟乙酯

通过异氰酸酯法在聚氨酯 ( PU)片表面引入聚甲基丙烯酸羟乙酯 ( PHEMA) ,以得到一种具有良好的机械性能和优良的血液相容性的高分子材料。用固 -液接触角分析所得样品表面性质 ,并进行血小板粘附实验。结果表明 :与 PU相比 ,在 PU表面接枝 PHEMA后其表面亲水性增加 ,粘附的血小板数量减少 ,变形也小     

一种新型热敏聚乳酸微球的制备与表征

背景：目前,基于聚乳酸的智能型微球是药物可控释放研究领域的热点。 目的：制备一种温度响应可控、生物可降解的微球载体。 方法：以甲基丙烯酸-2-羟乙酯作为丙交酯开环的引发剂,采用辛酸亚锡作为催化剂,并调节乳酸与甲基丙烯酸乙酯的比例,得到了不同分子质量的带双键聚乳酸(PDLLA-EMA)。以甲苯为溶剂,采用溶液合成法,自由基反应引发含有双键的聚乳酸以及N,N-异丙基丙烯酰胺共聚,成功制得了可降解温敏型共聚物(PNIPA-g-PDLLA-EMA)。采用复乳法,将PNIPA-g-PDLLA-EMA制成了微球。 结果与结论：实验制得PNIPA-g-PDLLA-EMA材料的热响应温度范围为35~42 ℃,基于该材料制得的微球粒径范围为(13.70±0.70)~(28.90±0.50) μm,粒径变化率为(138.7±4.20)%~(170.0±10.00)%,与同类材料相比,该微球已具备了应用于生物医学的潜在条件。关键词：智能型微球;可生物降解;聚乳酸;制备;载体 缩略语注释：PNIPAm：Poly N-isopropylacrylamide,聚(N-异丙基丙烯酰胺) doi:10.3969/j.issn.1673-8225.2012.16.015     

甲基丙烯酸钠修饰光交联海藻酸盐水凝胶支架的制备和表征

文题释义：甲基丙烯酸钠：是一种具有双功能的化学基团的有机小分子,一端含有2-甲基丙烯酰基,该基团具有良好的化学活性,可与化合物中的多种基团反应而修饰化合物;另一个功能集团就是拥有负电荷基团,能给修饰过的化合物材料表面带来稳定的负电荷。 光引发剂：又称光敏剂,是一类能在紫外光区(250-420 nm)或可见光区(400-800 nm)吸收一定波长的能量,产生自由基、阳离子等,从而引发单体聚合交联固化的化合物。引发剂分子在紫外光区(250-400 nm)或可见光区(400-800 nm)有一定吸光能力,在直接或间接吸收光能后,引发剂分子从基态跃迁到激发单线态,经系间窜跃至激发三线态;在激发单线态或三线态经历单分子或双分子化学作用后,产生能够引发单体聚合的活性碎片,这些活性碎片可以是自由基、阳离子、阴离子等。按照引发机制不同,光引发剂可分为自由基聚合光引发剂与阳离子光引发剂,其中以自由基聚合光引发剂应用最为广泛。 背景：光交联海藻酸盐水凝胶因具有良好的生物相容性、可微创注射等优势已为热门的组织工程研究材料,但是仍然存在强度不足、细胞黏附能力不足等问题。 目的：构建载负电荷的光交联海藻酸盐水凝胶材料,探索其物理性能和细胞黏附性能变化。 方法：利用海藻酸钠和2-氨乙基甲基丙烯酸酯盐酸盐制备甲基丙烯酸酯化海藻酸盐后,再与光引发剂和不同浓度甲基丙烯酸钠(0,20,40,60 mmol/L)混合制备载负电荷光交联海藻酸盐水凝胶,利用傅里叶红外光谱仪分析水凝胶的功能基团变化情况,扫面电镜观察水凝胶的表面形态,并测量其溶胀率。将MC3T3-E1细胞与各组水凝胶共培养48 h,采用活死染色与CCK-8法分析水凝胶的细胞毒性;接种MC3T3-E1细胞于4组水凝胶表面,在第4小时活死染色观察细胞早期黏附情况,第3天活死染色观察细胞伸展情况。 结果与结论：①傅里叶红外光谱分析显示,甲基丙烯酸钠的引入可在水凝胶红外波普波数1 600 cm^-1左右处出现来自甲基丙烯酸钠的新波峰;②扫描电镜显示随着甲基丙烯酸钠浓度的增加,光交联海藻酸盐水凝胶的致密度增加,孔径减小;③溶胀率测试显示随着甲基丙烯酸钠浓度的升高,光交联海藻酸盐水凝胶的溶胀率逐渐降低;④活死染色显示4种水凝胶表面的细胞生长状态良好,细胞活性均在95%以上;CCK-8检测显示,载负电荷的光交联海藻酸盐水凝胶材料无细胞毒性;⑤随着甲基丙烯酸钠引入量的增加,载负电荷光交联海藻酸盐水凝胶表面的早期细胞黏附率逐渐增加,细胞伸展状态明显改善;⑥结果表明,甲基丙烯酸钠修饰的引入调节了光交联海藻酸盐水凝胶物理性能,并明显提高了其细胞黏附性能。 ORCID: 0000-0002-1054-6002(赵德路) 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     

新型生物可降解交联N-乙烯基吡咯烷酮(NVP)材料的制备

用甘油和丙交酯在辛酸亚锡的催化下合成了可降解的三羟基中间体 ,在三乙胺存在的条件下 ,末端用丙烯酰氯进行功能化 ,合成了可降解的三乙烯基交联剂 ,并且对中间体和交联剂进行了FTIR ,1H—NMR ,GPC分析表征。这种交联剂与乙烯基吡咯烷酮 (NVP)用偶氮二异丁氰 (AIBN)为引发剂自由基引发聚合制备了组织工程支架材料 ,并且对材料的基本性能(吸水率和接触角 )进行了分析表征。     

共聚物表面亲疏水微相分离结构与抗凝血性

本文报告了由伯胺端基聚甲基丙烯酸羟乙脂与二替氰酸酯端基聚丁二烯反应制备嵌段共聚物的合成步骤以及对这些共聚物进行的红外光谱、凝胶渗透色谱、透射电镜、水可湿性等分析,同时通过Leewhite和微球柱法凝血试验评价了这些材料的抗凝血性。结果表明,疏水性的聚丁二烯球状微区(100-200)分散在亲水性的聚甲基丙烯酸羟乙醢基质里,共聚物获得较优良的抗凝血性。     

可降解扩链PLA聚合物拉伸强度的研究

目的探讨影响可降解骨内固定材料扩链PLA(聚丙交酯)聚合物拉伸强度的因素。方法根据国家GB-9641—88标准，将扩链PLA聚合物制成哑铃形试样，在不同温度、时间、扩链剂、交联剂、分子量条件下(聚丙交酯：聚己内酯=l：4)，用高分子万能试验机以5mm／min的拉伸速度测出拉伸强度。结果在扩链反应中的混合温度、混合时间、变定温度、变定时间、扩链剂、交联剂及端羟基聚丙交酯分子量大小对扩链PLA聚合物的拉伸强度均有影响。结论在聚丙交酯：聚己内酯=l：4时，混合温度为100％、混合时间为4min、变定温度为130℃、变定时间为6h、A扩链剂、交联剂-l及端羟基聚丙交酯分子量为300时，其拉伸强度最大，为24．47MPa。     

Cholesterol-modified superporous poly(2-hydroxyethyl methacrylate) scaffolds for tissue engineering

Modifications of poly(2-hydroxyethyl methacrylate) (PHEMA) with cholesterol and laminin have been developed to design scaffolds that promote cell–surface interaction. Cholesterol-modified superporous PHEMA scaffolds have been prepared by the bulk radical copolymerization of 2-hydroxyethyl methacrylate (HEMA), cholesterol methacrylate (CHLMA) and the cross-linking agent ethylene dimethacrylate (EDMA) in the presence of ammonium oxalate crystals to introduce interconnected superpores in the matrix. With the aim of immobilizing laminin (LN), carboxyl groups were also introduced to the scaffold by the copolymerization of the above monomers with 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA). Subsequently, the MCMEMA moiety in the resulting hydrogel was hydrolyzed to [2-(methacryloyloxy)ethoxy]acetic acid (MOEAA), and laminin was immobilized via carbodiimide and N-hydroxysulfosuccinimide chemistry. The attachment, viability and morphology of mesenchymal stem cells (MSCs) were evaluated on both nonporous and superporous laminin-modified as well as laminin-unmodified PHEMA and poly(2-hydroxyethyl methacrylate-co-cholesterol methacrylate) P(HEMA–CHLMA) hydrogels. Neat PHEMA and laminin-modified PHEMA (LN–PHEMA) scaffolds facilitated MSC attachment, but did not support cell spreading and proliferation; the viability of the attached cells decreased with time of cultivation. In contrast, MSCs spread and proliferated on P(HEMA–CHLMA) and LN-P(HEMA–CHLMA) hydrogels.     

Highly superporous cholesterol-modified poly(2-hydroxyethyl methacrylate) scaffolds for spinal cord injury repair

Modifications of poly(2-hydroxyethyl methacrylate) (PHEMA) with cholesterol and the introduction of large pores have been developed to create highly superporous hydrogels that promote cell-surface interactions and that can serve as a permissive scaffold for spinal cord injury (SCI) treatment. Highly superporous cholesterol-modified PHEMA scaffolds have been prepared by the bulk radical copolymerization of 2-hydroxyethyl methacrylate (HEMA), cholesterol methacrylate (CHLMA), and ethylene dimethacrylate (EDMA) cross-linking agent in the presence of ammonium oxalate crystals to establish interconnected pores in the scaffold. Moreover, 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA) was incorporated in the polymerization recipe and hydrolyzed, thus introducing carboxyl groups in the hydrogel to control its swelling and softness. The hydrogels supported the in vitro adhesion and proliferation of rat mesenchymal stem cells. In an in vivo study of acute rat SCI, hydrogels were implanted to bridge a hemisection cavity. Histological evaluation was done 4 weeks after implantation and revealed the good incorporation of the implanted hydrogels into the surrounding tissue, the progressive infiltration of connective tissue and the ingrowth of neurofilaments, Schwann cells, and blood vessels into the hydrogel pores. The results show that highly superporous cholesterol-modified PHEMA hydrogels have bioadhesive properties and are able to bridge a spinal cord lesion.     

PHEMA hydrogels modified through the grafting of phosphate groups by ATRP support the attachment and growth of human corneal epithelial cells

Converting the surface of poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel into a cell-adhesive surface has been successfully achieved through a method based on atom transfer radical polymerization (ATRP) grafting. Following activation of the surface hydroxyl groups of PHEMA by bromination, surface-initiated ATRP of mono(2-methacryloyloxyethyl) phosphate (MMEP) was conducted in a methanol-water system with Cu(I)Br as catalyst at room temperature. The conversion of PHEMA hydroxyl groups to brominated isobutyryl groups and the occurrence of grafting of PMMEP were confirmed by infrared and X-ray photoelectron spectroscopies. Cell attachment experiments were conducted by culturing human corneal limbal epithelial cells on the PMMEP-grafted PHEMA, and on unmodified PHEMA and tissue culture plastic for comparison. The results showed that the grafted PMMEP was homogeneously distributed, and the phosphate groups appeared to significantly promote the attachment, spreading and growth of cells, at a level comparable to the tissue culture plastic.     

Fabrication of a live cell-containing multilayered polymer hydrogel membrane with micrometer-scale thickness to evaluate pharmaceutical activity

We propose a spinning-assisted layer-by-layer method for simple fabrication of a multilayered polymer hydrogel membrane that contains living cells. Hydrogel formation occurred based on the spontaneous cross-linking reaction between two polymers in aqueous solution. A water-soluble 2-methacryloyloxyethyl phosphorylcholine polymer bearing phenylboronic acid groups (PMBV) and poly(vinyl alcohol) (PVA) were used as polymers for hydrogel membrane formation. Changing the number of hydrogel membrane layers, polymer concentration, spinning rate, and processing time for diffusion-dependent gelation of PMBV and PVA facilitated the regulation of the multilayered polymer hydrogel membrane thickness and morphology. We concluded that a multilayered polymer hydrogel membrane prepared using 5.0 wt% PMBV and 5.0 wt% PVA at a spinning rate of 2000 rpm was suitable for precise spatial control of cells in single layers. This multilayered polymer hydrogel membrane was used to prepare a single cell-laden layer to minimize barriers to the diffusion of bioactive compounds while preserving the three-dimensional (3-D) context. The pharmaceutical effects of one of the anticancer agents, paclitaxel, on a human cervical cancer line, HeLa cells, were evaluated in vitro, and the usability of this culture model was demonstrated.     

Semi‐Interpenetrating Hydrogel Networks of Poly(2‐hydroxyethyl methacrylate) with Poly[(D,L‐lactic acid)‐co‐(ε‐caprolactam)]

Semi‐interpenetrating hydrogel networks (IPNs) composed of poly(2‐hydroxyethyl methacrylate), PHEMA, and poly[(D ,L ‐lactic acid)‐co‐(ε‐caprolactam)], copoly(D,L ‐LA/ε‐CLM), were synthesized. Linear copoly(D,L ‐LA/ε‐CLM) chains were interpenetrated into the crosslinked three‐dimensional networks of PHEMA. Physical properties of IPN samples such as stress‐strain behavior, swelling, extraction and glass transition (T_g) were examined. Glass transition temperature of the PHEMA was shifted to lower temperatures, indicating interpenetration of PHEMA and copoly(D,L ‐LA/ε‐CLM) chains. The extraction results showed that the entrapping level between two components of PHEMA/copoly(D,L ‐LA/ε‐CLM) in simultaneous semi‐IPN is very high. These results confirm that the decrease in swelling ratios with increase in copoly(D,L ‐LA/ε‐CLM) contents is probably due to the entanglement effect. Semi‐IPNs showed higher ultimate strength and modulus but lower elongation with respect to pure PHEMA hydrogel. The semi‐IPN samples exhibited brittle fracture morphology which is consistent with tensile properties.     

Mass uptake study of the diffusion of water and SBF into poly(2-hydroxyethyl methacrylate-co-tetrahydrofurfuryl methacrylate) containing aspirin or vitamin B12

The ingress of water and Kokubo simulated body fluid (SBF) into poly(2-hydroxyethyl methacrylate) (PHEMA), and its co-polymers with tetrahydrofurduryl methacrylate (THFMA), loaded with either one of two model drugs, vitamin B12 or aspirin, was studied by mass uptake over the temperature range 298-318 K. The polymers were studied as cylinders and were loaded with either 5 wt% or 10 wt% of the drugs. From DSC studies it was observed that vitamin B12 behaved as a physical cross-linker restricting chain segmental mobility, and so had a small anti-plasticisation effect on PHEMA and the co-polymers rich in HEMA, but almost no effect on the Tg of co-polymers rich in THFMA. On the other hand, aspirin exhibited a plasticising effect on PHEMA and the co-polymers. All of the polymers were found to absorb water and SBF according to a Fickian diffusion mechanism. The polymers were all found to swell to a greater extent in SBF than in water, which was attributed to the presence of Tris buffer in the SBF. The sorptions of the two penetrants were found to follow Fickian kinetics in all cases and the diffusion coefficients at 310 K for SBF were found to be smaller than those for water, except for the polymers containing aspirin where the diffusion coefficients were higher than for the other systems. For example, for sorption into PHEMA the diffusion coefficient for water was 1.41 x 10(-11) m2/s and for SBF was 0.79 x 10(-11) m2/s, but in the presence of 5 wt% aspirin the corresponding values were 1.27 x 10(-11) m2/s and 1.25 x 10(-11) m2/s, respectively. The corresponding values for PHEMA loaded with 5 wt% B12 were 1.25 x 10(-11) m2/s and 0.74 x 10(-11) m2/s, respectively.     

Functional polymer hydrogels for embryonic stem cell support

Embryonic stem (ES) cells are pluripotent cells with the ability to differentiate among all embryonic and adult cell lineages. Derivation of human ES cells opened up the way for treatment of many serious disorders by stem cell-based transplantation therapy. One of the most exciting challenges in development of transplantation therapies is to repair the damaged part of the organ or tissue by transplantation of undifferentiated ES cells or their differentiated derivatives within three-dimensional polymer scaffold. This method allows both renewal of structure and restoration of function of the organ. To address this issue, new polymer hydrogels were synthesized and tested. Cationic hydrogel slabs were synthesized by bulk radical copolymerization of 2-hydroxyethyl methacrylate (HEMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) with ethylene dimethacrylate (EDMA) or 1-vinyl-2-pyrrolidone (VP) with N,N'-divinylethyleneurea (DVEU) or EDMA in the presence of saccharose or NaCl as a porogen. Swelling studies of the synthesized copolymers showed a high water content in the swollen state. Biocompatibility was studied with the use of feeder-independent mouse ES cell line D3. Cells grown either on the surface or inside synthesized polymer slabs suggest that the tested slabs are not toxic. The ability of ES cells to proliferate was only partially limited in PHEMA slabs crosslinked with EDMA compared with standard culture conditions. When cultured for a limited period of time, ES cells retained their undifferentiated state independently of properties of the hydrogel slabs, presence or absence of surface charges, type of crosslinking agent and matrix (PHEMA or PVP). Notably, prolonged culture in superporous hydrogel slabs initiated ES cell differentiation. Compared with unmodified PHEMA, the number of proliferating ES cells was still lower in the presence of cationic polymers.     

pH- and Temperature-Responsive P(DMAEMA-GMA)-Alginate Semi-IPN Hydrogels Formed by Radical and Ring-Opening Polymerization for Aminophylline Release

A novel poly((2-dimethylamino) ethyl methacrylate-glycidyl methacrylate)-alginate (P(DMAEMA-GMA)alginate) semi-IPN hydrogel was synthesized via radical polymerization of the double bonds and ring-opening of the epoxy groups without using catalyst and cross-linker. ¹H-NMR, FT-IR and DSC data were consistent with the expected structures for the hydrogels. The interior morphology of the hydrogels was also investigated by SEM. The swelling ratio and compressive strength of the hydrogels were measured. The semi-IPN hydrogel had pH and temperature sensitivity, and pH-sensitive points of all hydrogels were found to be at pH 5.0. The release behavior of the model drug, aminophylline, was found to be dependent on the hydrogel composition and environment pH, which manifests that these materials have potential applications as intelligent drug carriers.     

Synthesis and characterization of dextran-methacrylate hydrogels and structural study by SEM

The objectives of this study were to develop a simple and reproducible method for the preparation of the hydrogel precursor dextran-methacrylate and to conduct a visual observation of the interior structure of the swollen dextran-methacrylate hydrogel with minimum artifacts. A dextran-methacrylate hydrogel precursor was synthesized by reacting dextran with methacrylic anhydride in the presence of triethylamine as a catalyst. The effects of reaction time, temperature, concentration, and catalyst amount were studied to obtain a wide range of degree of substitution (DS) in dextran by methacrylate. The dextran-methacrylate synthesized showed an enhanced solubility in water and common organic solvents. UV irradiation of dextran-methacrylate by a long-wave UV lamp (365 nm) generated a photocrosslinked hydrogel. This dextran-methacrylate hydrogel showed a range of swelling ratio from 67 to 227% and exhibited an increase in swelling ratio with a decrease in methacrylate substitution. The pH of the swelling media did not affect the swelling behavior of the dextran-methacrylate hydrogels at all the degrees of substitution used. Special cryofixation and cryofracturing techniques were used to prepare aqueous swollen dextran-methacrylate hydrogel samples for SEM observation of their surface and interior structures. A unique three-dimensional porous structure was observed in the swollen hydrogel but was absent in the unswollen hydrogel. Different pore sizes and morphologies between the surface and the interior of swollen hydrogels also were observed.     

Study on Mechanical and Biological Properties of Autopolymerizing Hydrogel for Denture Soft Lining Material

Denture soft lining materials have been recongnized in prosthodontic clinicalpractice for many years.They act as enabling uniform distribution of pressure ondenture- bearing tissues and reducing discomfort for patients with sharp or severelyreabsorbed alveolar ridges and sensitive mucosa〔1〕.However,the present two mainkinds of soft liners still existsome shortcomings respectively,i.e.the plasticizeacrylics may become harder and harder as the using time passed;the silicone elas-tomers may pre…