Drug permeation through a temperature-sensitive poly(N-isopropylacrylamide) grafted poly(vinylidene fluoride) membrane

Poly(N-isopropylacrylamide) (poly(NIPAAm)) is a temperature sensitive polymer, which has been used in the development of thermally controlled devices. In the present study, poly(NIPAA)m grafted poly(vinylidene fluoride) (PVDF) membranes were prepared by an irradiation method and fluxes of model compounds across the various grafted membranes were measured. The effectiveness of various grafted membranes to control drug fluxes by temperature was studied using FITC-dextrans (molecular weights 4400-50 600) and mannitol as model compounds. Also, the effect of environmental conditions on the LCST of the membrane was evaluated. The fluxes of bigger molecules across a temperature sensitive, porous poly(NIPAA)m-PVDF membranes were effectively controlled by temperature, environmental ionic strength and degree of grafting of the membrane, while flux of the smaller molecules was not controlled thermally even at high degree of membrane grafting. These result indicates that the studied membranes are useful in controlling the permeation of high molecular weight compounds such as polynucleotides, peptides and proteins. (C) 1998 Elsevier Science B.V. All rights reserved.