Poly[(R)-3-hydroxybutyric acid] (natural origin)

PHB is a fully biodegradable polyester with optical activity, piezoelectricity, and very good barrier properties. PHB is a partially crystalline material with a high melting temperature and a high degree of crystallinity. PHB is a thermoplastic, belonging to the family of polyhydroxyalkanoate PHAs. It has physical- and mechanical properties comparable to those of isotactic polypropylene iPP. Different bacterial types of microorganisms produce PHB from renewable sources from sugar and molasses as intracellular storage materials. It can be used in applications of drug-loaded medical devices and microspheres as implantable and injectable therapeutic systems in medicine for treatment of various diseases. Besides application of PHB for producing of medical devices and systems of sustained drug delivery, PHB can be used for production of systems for controlled release of activators or inhibitors of enzymes. The use of these systems allows the development of the physiological models for prolonged local activation or inhibition of enzymes in vivo. The PHB is a perspective tool in design of novel physiological models due to minimal adverse inflammatory tissue reaction to PHB matrixes implantation or PHB microspheres administration.