Polyhydroxyalkanoates applications in drug carriers

Abstract

Drug delivery carriers (DDCs) have been successfully used in the previous years for the controlled release of therapeutic compounds for the treatment and cure as well as the diagnosis of many diseases including cardiovascular disorders, HIV infection, Alzheimer's disease, rheumatoid arthritis, and cancer. Several biodegradable/ biocompatible polymers including poly-(lactic acid-co-glycolic acid), poly-L-lactic acid, and poly-L-lysine have been used as drug carriers for the transportation and controlled release of therapeutic compounds to the tissue or cells of action. Amongst the various biodegradable polymers tested as DDCs, polyhydroxyalkanoates (PHAs) were extensively investigated due to their unique biochemical properties. The practical applications of PHAs in biomedical/ pharmaceutical areas have been approved by FDA in 2007. PHAs are suitable for in vivo therapeutic applications including tissue coating, tissue regeneration devices, stents, tubing, bone or tissue cement wound dressings, and drug delivery. PHAs are biodegradable, biocompatible, and hydrophobic while they are used to produce microspheres, microcapsules, and nanoparticles as well as films and porous matrices. Most importantly, PHAs have significant advantages over other biodegradable polymers, since their degradation products, including oligomers and monomers, are not toxic to the surrounding tissues. The variety of PHAs, along with their biocompatibility and their excellent biochemical and physical properties, make them excellent biopolymers for use in drug delivery. The activity of some anti-cancer agents was enhanced when they combined with PHAs or HA monomers. PHA-based microspheres, nanoparticles, non-woven membranes, and hydrogels have been successfully used as carriers of therapeutic agents for several diseases including cancer and inflammatory diseases.