POLYHYDROXYALKANOATES (PHAs) FOR TISSUE ENGINEERING APPLICATIONS: BIOTRANSFORMATION OF PALM OIL MILL EFFLUENT (POME) TO VALUE-ADDED POLYMERS

The study of cancer cell has been hindered by the lack of appropriate ex vivo models, which can mimic this microenvironment. It is hypothesized that the fabrication of porous 3-D scaffolds for the biomimetics growth of cancer cells ex vivo could facilitate the study of the disease in its native 3-D niche. For that reason, biomaterials are used for fabrication of 3-D scaffold, in general, may be natural polymers such as proteins, collagens and gelatin, or synthetic biopolymers. Among the various available biodegradable polymers, polyhydroxyalkanoates (PHAs) have gained significant interest as one of the value-added materials which can be synthesized from abundantly available source of palm oil mill effluent (POME). Down the group of the PHA, poly-3-hydroxybutyrate (PHB) and copolymerizing this PHB that produced PHBVs; these two polymers have the most prevalent polymer used for scaffolds fabrication. A physico-chemical and biological modification has developed to improve wetting, adhesion, and printing of polymer surfaces, generally by introducing a variety of polar groups. These techniques must be tailored to introduce a specific functional group when the surface modification is a precursor to attach a bioactive compound. There are a few methods in order to fabricate porous 3-D scaffolds such as solvent casting, particulate leaching, thermally induced phase separation, gas forming, fiber bonding, electrospinning and also solid free form method. A review of the polyhydroxyalkanoates (PHAs) for tissue engineering applications is presented, beginning with the basic naturally derived polymerization of PHAs, biotransformation of palm oil mill effluent (POME) to the value-added polymers, novel methods of scaffold fabrication capabilities and its physico-chemical and biological surface modifications to increase cell-biomaterial affinity.