Synthesis of Photocrosslinkable Copolymers of Cinnamoyl Group-modified Methacrylate and 2-Hydroxyethyl Methacrylate, and Fibroblast Cell Growth on Their Thin Films

Cinnamoyl-modified methacrylate, 2-cinnamoyloxyethyl methacrylate (CEMA), was synthesized from 2-hydroxyethyl methacrylate (HEMA) and cinnamoyl chloride. Copolymers with various cinnamoyl contents were synthesized by random copolymerization of HEMA and CEMA at different feed ratios. Thus three copolymers with different CEMA contents were synthesized, and the monomer composition ([HEMA]:[CEMA]) in the copolymers ranged from 75:25 to 0:100. The coating films of copolymers on glass plates were prepared by the dip-coating method. Photo-induced dimerization of the cinnamoyl groups in the copolymers was confirmed by the ultraviolet-visible (UV-Vis) spectral changes. The cell proliferation on the photocrosslinked copolymers was tested using 3T3 Swiss albino mouse embryo fibroblasts. The results of the cell proliferation assay revealed that the photocrosslinked copolymers carrying more cinnamoyl groups promoted the cell proliferation compared with the photocrosslinked copolymers carrying less cinnamoyl groups. According to the results in the present study and our previous studies on cinnamoyl-modified trehalose and cinnamoyl-modified hydroxypropyl cellulose, it is presumable that the photodimerized cinnamoyl groups existing on the surface of materials at high density have some preferable effect on promoting fibroblast cell adhesion.