A biopolymer known as polyhydroxyoctanoate (PHO), belonging to a relatively new group of polymers, will be evaluated for potential applications in drug and vaccine delivery. The objectives will be: to develop a reproducible fermentation method for PHO biopolymer production; characterize the biodegradable polymer; prepare microspheres and microcapsules of PHO containing a hydrophilic drug, a hydrophobic drug, and a vaccine; and, evaluate the PHO microspheres and microcapsules in controlled release. Particular attention will be paid to the development of a non-solvent based method of encapsulation, exploiting the low melting point of the PHO polymer. Such a method is highly sought after since current methods using solvents in microsphere formation frequently result in loss of bioactivity of the drug or vaccine. The advantages of encapsulation with a biodegradable polymer include: potential to develop single-injection immunization and therapeutic methods; controlled release of a bioactive molecule; maintenance of bioactivity; and, provision for new routes of administration.Proposed commercial application:The potential commercial opportunities of this research are to provide a new biopolymer for assessment in controlled-release of drugs and vaccines. Opportunities exist to develop: solvent free methods for encapsulation of drugs and vaccines in microspheres; single-injection immunization methods; methods to deliver bioactive molecules over prolonged periods of time; and, alternative methods of drug and vaccine administration.National Institute fo General Medical Sciences (NIGMS)
