私密直播全婐app免费大渔直播,国产av成人无码免费视频,男女同房做爰全过程高潮,国产精品自产拍在线观看

當前位置:> 首頁 > 論文著作 > 正文
Enzyme-mediated fast in situ formation of hydrogels from dextran-tyramine conjugates

Dextran hydrogels were formed in situ by enzymatic crosslinking of dextran-tyramine conjugates and their mechanical, swelling and degradation properties were evaluated. Two types of dextran-tyramine conjugates M-n,M-dextran = 14k, M-w/M-n = 1.45), i.e. dextran-tyramine linked by a urethane bond (denoted as Dex-TA) or by an ester-containing diglycolic group (denoted as Dex-DG-TA), with different degrees of substitution (DS) were prepared. Hydrogels were rapidly formed under physiological conditions from Dex-TA DS 10 or 15 and Dex-DG-TA DS 10 at or above a concentration of 2.5 wt% in the presence of H2O2 and horseradish peroxidase (HRP). The gelation time ranged from 5 s to 9 min depending on the polymer concentration and HRP/TA and H2O2/TA ratios. Rheological analysis showed that these hydrogels are highly elastic. The storage modulus (G), which varied from 3 to 41 kPa, increased with increasing polymer concentration, increasing HRP/TA ratio and decreasing H2O2/TA ratio. The swelling/degradation studies showed that under physiological conditions, Dex TA hydrogels are rather stable with less than 25% loss of gel weight in 5 months, whereas Dex-DG-TA hydrogels are completely degraded within 4-10 d. These results demonstrate that enzymatic crosslinking is an efficient way to obtain fast in situ formation of hydrogels. These dextran-based hydrogels are promising for use as injectable systems for biomedical applications including tissue engineering and protein delivery.

主站蜘蛛池模板: 若羌县| 彭山县| 惠安县| 黑河市| 宁海县| 西畴县| 宜君县| 石台县| 大名县| 江陵县| 茂名市| 扶余县| 三河市| 建宁县| 合阳县| 霍州市| 长治市| 安宁市| 定兴县| 伊金霍洛旗| 满城县| 德钦县| 墨脱县| 东乌珠穆沁旗| 潍坊市| 金阳县| 曲靖市| 伊金霍洛旗| 锡林浩特市| 彝良县| 湟中县| 浮山县| 咸阳市| 平度市| 土默特左旗| 镇沅| 镶黄旗| 丰宁| 武义县| 巩留县| 绥江县|