RETINAL PIGMENTED EPITHELIUM CULTURES ON THERMALLY RESPONSIVE POLYMERPOROUS SUBSTRATES

A cross-linkable co-polymer of UV-sensitive 4-(N-cinnamoylcarbamide)me thylstyrene (CCMS) and N-isopropylacrylamide (NIPAAm), was applied to porous tissue culture inserts. Surface chemical analyses of the insert s show an introduction of a thermally responsive polymer comparable to that on similarly incorporated non-porous polystyrene surfaces. Conta ct angle measurements as well as atomic force microscopy show a surfac e change in response to changing temperature in an aqueous environment , from hydrophilic, extended polymer chains below 32 degrees C to a de nse hydrophobic film above 32 degrees C. Cell growth on porous inserts allowed measurement of cell expression, such as transepithelial resis tance and fluid transport, which are not observable on cells from non- porous surfaces. Cultures of retinal pigmented epithelium (RPE) were a ble to restore an environment similar to in vivo by forming a tight ju nction barrier membrane upon confluence at 37 degrees C, as observed b y changes in morphology, transepithelial resistance, and directionally -specific fluid transport. In addition, cells cultured on these surfac es detached as an oriented polarized sheet when the inserts were broug ht to 20 degrees C. This cell sheet was transplanted to other tissue c ulture surface without polymer detachment or dissolution, or cell dama ge caused by traditional detachment methods using proteolytic enzymes.