Three-dimensional fast-degrading polymer films for delivery of calcium phosphate/DNA co-precipitates in solid-phase transfection

We prepared Ca-P/DNA co-precipitates deposited and encapsulated in polymer films for substrate-mediated gene delivery. The polymer films were composed of fast-degrading functionalized star poly(DL-lactide) CA-PDLLA and block copolymer poly(L-lactide)-poly(ethylene glycol)-poly(L-lactide) (PLLA-PEG-PLLA). The in vitro gene transfections of pGL3-Luc and pEGFP-C1 plasmids in HEK293T cells mediated by different films were studied. The effect of presence of a water-soluble polymer, poly-alpha,beta-[N-(2-hydroxyethyl)-L-aspartamide], on the transfection activity of the film-mediated transfection was studied. The gene expressions could be effectively mediated by the Ca-P/DNA co-precipitates deposited and encapsulated in polymer films. During the cellular transfection, the fast-degrading films rapidly released Ca-P/DNA co-precipitates to mediate gene transfection, and the degradation products did not show any negative effects on the gene expression. The Ca-P/DNA co-precipitates deposited and encapsulated in films have promising applications in substrate-mediated gene delivery.