Gelatin multilayers assembled on poly(L-lactic acid) surface for better cytocompatibility

Gelatin multilayers were assembled on PLLA substrate at pH 3, 5, and 7, which was below, around, and above the isoelectric point of the amphoteric polymer, using the layer-by-layer assembly technique. The multilayer deposition on the PLLA substrate was monitored by X-ray photoelectron spectroscopy (XPS) and water contact angle measurement. The XPS, water contact angle, and atomic force microscopy data indicated that the layer thickness, surface hydrophilicity, and surface morphology of the gelatin multilayers assembled strongly depended on the pH at which the layers were deposited. Chondrocyte culture was used to test the cell attachment, cell morphology, and cell viability on the PLLAs modified with gelatin multilayers. All these modified PLLAs exhibited dramatically improved cytocompatibility compared with the virgin PLLA, and even better performance than that of tissue culture polystyrene (TCPS). The best cell compatibility was observed for the gelatin multilayers assembled at pH = 5. These results indicate that the cell compatibility of biodegradable polyesters can be effectively and facilely improved by assembly of gelatin multilayers, and the performance can be controlled by adjusting the solution pH at which the multilayers are deposited. This may help the design and fabrication of better scaffolds for tissue engineering. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008