Аннотация:A promising branch of biomedicine is the creation of polymeric forms from aliphatic polyesters, doped with biologically active compounds (BAC), for bones temporary prostheses, wound dressings, constructions for controlled drug delivery, etc. Doping of a polymer with BAC is also used for preventing inflammatory processes, stimulating tissue growth. The main characteristics of such constructions are predetermined rates of the BAC release and the polymer degradation. Polylactide undergoes autocatalytic hydrolytic destruction in aqueous solutions forming lactic acid oligomers and catalyzed by acids and bases. It leads to changes in BAC release, kinetics of the polymer erosion, and, possibly, a partial loss of the biological activity of the dopant in acidic media inside the polymer construction. Therefore there is a purpose to monitor the acidity inside the liquid-filled pores of aliphatic polyester’s matrices during their swelling and hydrolysis. In our work, this problem is solved by impregnation of poly-D,L-lactide films with pH-sensitive nitroxyl radical 5,5-dimetyl-4-dimetylamino-2-ethyl-2-(4-pyridyl)-2,5-dyhydroimidazole-1-oxyl (DPI) as a dopant. Using nitroxides also allows to establish the release profiles of the probe from the films, the microacidity and micromobility of the probe, as well to measure the amount of the probe inside the film during degradation.
