The surface modification of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymers to improve the attachment of urothelial cells

Biocompatible and biodegradable poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(HB-co-HHx)] substrates were modified to improve the attachment of porcine urothelial cell culture. The pristine copolymer exhibits excellent mechanical properties to replace the bladder tissue, but its surface lacks chemical functionalities to interact with cells. Thus, wet chemical treatments based on NaOH and ethylenediamine in aqueous [ED(aq)] and isopropanol [ED(isoOH)] media to functionalize the P(HB-co-HHx) films surfaces were compared. Among these treatments, short ED(aq) treatment was able to decrease the hydrophobicity, rendering a surface with amino groups and without a significant alteration of the mechanical properties. Furthermore, to enhance the interaction with urothelial cells, laminin derived YIGSR sequence was covalently bound to these amino functionalized substrates. The focal attachment was clearly improved with this last treatment, comparing with those results found with the unmodified and first-step functionalized P(HB-co-HHx).