Analysis of the Structure of Polyhydroxybutyrate-Based Fibrous Matrices for Prolonged Drug Release

Abstract

Abstract—This paper studies the supramolecular structure of polymer matrices for prolonged release of medicinal substances on the basis of ultrafine polyhydroxybutyrate fibers obtained by electrospinning. Dipyridamole was chosen as a model drug. The concentration of dipyridamole in the fibers ranged from 1 to 5%. Using the methods of scanning electron microscopy, differential scanning calorimetry, and electron paramagnetic resonance, the morphology of nonwoven fibrous materials was investigated. It was found that the geometry of the fibers changes upon adding dipyridamole. Polyhydroxybutyrate fibers are characterized by a nonequilibrium supramolecular structure. Introduction of dipyridamole leads to additional crystallization of the fibers, which is also accompanied by slowing down of molecular mobility in the amorphous regions of the polymer.