Dynamic Layer-by-Layer Films: A Platform for Zero-Order Release

Zero-order release is the ultimate goal of controlled drug release systems, however, it still remains a big challenge despite of numerous previous efforts. Here we show that the release of P­(AAm-3-AAPBA) from P­(AAm-3-AAPBA)/PVA film, a dynamic layer-by-layer (LBL) film, follows a perfect zero-order kinetics, provided that both polymers in the film have a narrow molecular weight distribution. Instead of releasing via diffusion or degradation, P­(AAm-3-AAPBA) is released from the film via the dissociation of the interpolymer complex. The release rate is determined by molecular weight of the polymers. One could also tune the release rate via various external environmental stimuli, including pH, temperature, and glucose. The results suggest dynamic LBL film could serve as a new drug release platform that allows for not only zero-order release, but also intelligent release.