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魔芋葡甘聚糖的磷酸酯化改性研究 总被引：2，自引：6，他引：2
[目的]研发新型的生物可降解凝胶。[方法]以魔芋葡甘聚糖为主要原料、三聚磷酸钠为交联剂,合成了生物可降解的磷酸酯化魔芋葡甘聚糖水凝胶,并探讨了该水凝胶的溶胀动力学以及不同反应条件对凝胶平衡溶胀比的影响,并通过体外降解试验分析了该水凝胶的生物可降解性。[结果]该水凝胶在溶胀初期溶胀比迅速增加,随着溶胀时间的延长,溶胀比增长逐渐变慢,8 h后达到溶胀平衡。该水凝胶的平衡溶胀比随魔芋葡甘聚糖用量的增加而逐渐升高,随着交联剂三聚磷酸钠用量的增加而逐渐降低。该水凝胶可被含有β-葡聚糖苷酶的纤维素酶降解,而不能被不含β-葡聚糖苷酶的胰酶等降解,保持了魔芋葡甘聚糖所具有的生物可降解性。[结论]磷酸酯化魔芋葡甘聚糖水凝胶可作为用于结肠定位释药的生物可降解水凝胶。 相似文献
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将羧甲基甲壳素与海藻酸钠共混制备复合水凝胶,并探讨了pH、海藻酸钠与羧甲基甲壳素的共混比例、海藻酸钠浓度、交联剂用量等因素对其溶胀性能的影响。结果表明,当两者的共混比例为4∶6、海藻酸钠浓度为4.5%、羧甲基壳聚糖浓度为5.0%、交联剂用量为0.30时,水凝胶的溶胀率较大;在pH=1.2时,BSA的释放率为5.60%,而当pH=7.4时,BSA的累积释放率达到79.80%。该水凝胶能在胃部的酸性环境中保护大分子药物,从而将其运载到高pH的肠道中并释放,显示出用于口服药物缓释体系的应用潜力。 相似文献
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Seung-Taek Oh Oh-Jin Kwon Byoung-Chul Chun Jae-Whan Cho Jong-Shin Park 《Fibers and Polymers》2009,10(1):21-26
We produced a protein loaded, pH-sensitive alginate-bentonite hydrogel for wound dressings. Alginate is a nontoxic polysaccharide
with favorable pH-sensitive properties that make it useful for the intestinal delivery of protein drugs. However, the use
of alginate for drug delivery is limited by drug leaching and rapid dissolution of alginate at the higher pH, which may result
in lower entrapment efficiency and a burst in the release of entrapped protein drugs. To overcome these problems, we created
a novel cross-linked alginate-bentonite hydrogel by combining mineral-rich bentonite with the alginate matrix along with an
additive to ensure controlled release. We analyzed the gel in the drug loading process in an aqueous environment by looking
at the release profiles of a model protein drug (BSA) from the hydrogel at pH values of 4.5, 5.2 (skin area) and 7.4, 9.2
(wound area). The swelling ratio decreased with bentonite concentration, but did not fall below 6. The rate of drug release
was slowest at a pH value of 4.5 and fastest at a pH value of 9.2. The rate of drug release decreased with bentonite concentration.
The presence of bentonite prevents the rapid dissolution of alginate at the higher pH, ensuring the controlled release of
the entrapped drug. 相似文献
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The objective of this study is to examine the feasibility of using visible light to form gels from polysaccharide precursors.
Hydrogel formation by visible light irradiation would be very beneficial because visible light is a benign light source and
ready available when compared with other light sources such as UV. Dextran-methacylate was synthesized and photocrosslinked
using (−)-riboflavin as a photoinitiator and L-arginine as a co-initiator under the visible light. The effect of various concentrations
of (−)-riboflavin and L-arginine on the photo-crosslinking of dextran-methacrylate hydrogel was investigated. The fabricated
hydrogel was characterized by FT-IR and SEM. The photoinitiator [(−)-riboflavin] and co-initiator (L-arginine) as well as
dextran precursor are completely biocompatible. The optimum condition for the biocompatible dextran-based hydrogel formation
under the harmless light source (visible light) was elucidated in this study. In general, the (−)-riboflavin, 0.01–0.5 %,
and L-arginine, 5–20 % of the weight of dextran-methacrylate were the best condition in forming dextran-based hydrogels under
the visible light. The three-dimensional hydrogel structure was verified by SEM morphology of swollen hydrogels. Photocrosslinking
under the visible light source would enlarge the applications of this type of photocrosslinking in the biomedical area (e.g.,
eyes or other light-sensitive organs). 相似文献
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Manjeet?JassalEmail author Ritwik?Chattopadhyay Debojyoti?Ganguly 《Fibers and Polymers》2004,5(2):95-104
A series of superabsorbents based on acrylic acid (AA), sodium acrylate, 2-acrylamido-2-methylpropane sulphonic acid, N,N′-methylene
bis-acrylamide (MBA) were prepared by inverse suspension polymerization. These hydrogels were further crosslinked on the surface
with polyethylene glycol-600 (PEG-600). The water absorbency or swelling behaviors for these xerogels in water and 0.9% saline
solutions, both under free condition and under load were investigated. Absorption characteristics of these hydrogels were
found to depend on nature and concentration of crosslinker in the system. It was also found that the saline absorption was
significantly improved as the incorporation of AMPS in the polymer was increased. The surface crosslinking introduced in the
polymers was found to improve the absorption under load characteristics without lowering the free water absorption capacities
of the polymer to a considerable extent. 相似文献
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[目的]把聚乙烯吡咯烷酮与壳聚糖的大分子链进行交联,破坏壳聚糖大分子链的规整结构,增强壳聚糖的亲水性,改善对脂肪的吸附能力。[方法]以戊二醛为交联剂,通过壳聚糖大分子链的羟基和氨基,在壳聚糖大分子链之间形成化学交联点,同时网络聚乙烯吡咯烷酮,形成半互穿网络结构,合成聚乙烯吡咯烷酮(PVP)/壳聚糖(CS)交联水凝胶。最后,考察交联剂的用量对凝胶溶胀度和脂肪吸附能力的影响。[结果]红外光谱分析证明发生了交联反应,形成半互穿网络结构。SEM照片观察到PVP/CS交联凝胶表面呈微相分离。性能的测定结果表明,该凝胶在水中有很好的溶胀性,当交联剂的用量为2.5 ml时,凝胶的溶胀度最大。[结论]壳聚糖交联聚维酮凝胶对脂肪的吸附能力比起单纯的壳聚糖有很大的提高。 相似文献
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