von Recum H, Okano T, Wan Kim S
Department of Bioengineering, University of Utah, Salt Lake City, UT, 84112, USA.
J Control Release. 1998 Nov 13;55(2-3):121-30. doi: 10.1016/s0168-3659(98)00042-x.
Thermally reversible poly(N-isopropylacrylamide) (PIPAAm) was covalently grafted onto tissue culture dishes to allow detachment of cultured cells upon temperature change from physiological to room temperature. In addition the grafted polymer matrix was used to entrap biomolecules such as growth factors either to be released by diffusion early in cell cultures, or remain entrapped and be reversibly exposed to cell receptors. Experiments with model proteins trypsin and insulin show that amount loaded and released depends upon the PIPAAm grafting density. Dishes grafted with 2.5 microgram/cm2 PIPAAm released approximately four times more model protein over 4 h than dishes grafted with 1.8 microgram/cm2. This in vitro drug delivery system can be used to deliver factors to the basal side of cells early in cell culture by providing high local concentrations without high bulk concentration. Cultures of human retinal pigmented epithelium showed higher growth rate on insulin loaded dishes than on controls containing a similar bulk solution concentration. These cultures retained the ability to detach singly or as confluent sheets from the loaded surfaces.
热可逆聚（N-异丙基丙烯酰胺）（PIPAAm）被共价接枝到组织培养皿上，以便在温度从生理温度变为室温时使培养的细胞脱离。此外，接枝的聚合物基质用于包封生物分子，如生长因子，使其在细胞培养早期通过扩散释放，或保持包封状态并可逆地暴露于细胞受体。用模型蛋白胰蛋白酶和胰岛素进行的实验表明，加载和释放的量取决于PIPAAm的接枝密度。接枝有2.5微克/平方厘米PIPAAm的培养皿在4小时内释放的模型蛋白比接枝有1.8微克/平方厘米的培养皿多大约四倍。这种体外药物递送系统可用于在细胞培养早期通过提供高局部浓度而不产生高总体浓度的方式将因子递送至细胞的基底侧。人视网膜色素上皮细胞培养物在加载胰岛素的培养皿上比在含有相似总体溶液浓度的对照培养皿上显示出更高的生长速率。这些培养物保留了从加载表面单独或作为汇合片脱离的能力。
