Chemical structures and compositions of peptide copolymer films affect their functional properties for cell adhesion and cell viability

In this study we synthesized peptide copolymers containing benzyl glutamate (BG) moiety (to enhance cell viability) and lysine derivatives (to improve cell adhesion) for use in tissue engineering. We examined the effects of two lysine derivatives: Nε-t-butyloxycarbonyl lysine (BOCL) and Nε-carbobenzoxy lysine (CBZL). The cell behavior on the copolymer films was influenced by the functional characteristics of the copolymers, governed by their chemical structures and compositions. A BOC unit on the lysine side chain is bulkier than a CBZ unit, resulting in a rougher film surface displaying poorer adhesion. The film's hydrophilicity and cell adhesion properties were improved by increasing the CBZL content in the copolymers, due to the presence of the amide linkages of the CBZ units. The copolymer film prepared with an equal molar ratio of CBZL and BG exhibited the best cell performance, resulting from a balance in the copolymer's functional properties. The cell behavior on this film was further improved by partially hydrolyzing the copolymer to produce net positive charge, thereby increasing the hydrophilicity and cell recognition. These novel copolymers appear suitable for use as films for enhancing cell culturing during tissue engineering.