Synthesis of Temozolomide-Loaded PHB-PEI Nanoparticles for In-Vitro Drug Release

During the past decades many synthetic polymers have been studied for nanomedicine applications and an in particular as drug delivery systems. For this purpose, polymers must be non-toxic, biodegradable, and biocompatible. Polyhydroxybutyrate (PHB) is a polyhydroxyalkanoates (PHA) produced by number of bacteria as granules using fatty acids, sugars and other carbon sources. The biodegradable and biocompatible nature of PHB makes it suitable to be used as a drug delivery system.Temozolomide (TMZ) is an alkylating agent, used largely in the therapy of malignant brain tumors including glioblastoma and astrocytoma, which are serious and aggressive types of brain cancers. It readily crosses the blood-brain barrier and has a broad spectrum of antineoplastic activity. The aim of this study was to prepare TMZ loaded PHB-PEI nanoparticles using emulsion solvent evaporation method. The particle size, size distribution and the surface charges of the nanoparticles were measured using a Nano Zetasizer equipped with a dynamic light scattering detector.The drug loading (DL) and encapsulation efficiency (EE) of TMZ/PHB-PEI nanoparticles were determined by HPLC analysis. Nanoparticles were separated from the aqueous medium by ultracentrifugation. The amount of the drug present in nanoparticle networks was determined as the difference between the total amount of TMZ used to prepare the nanoparticles and the amount of remaining TMZ in the aqueous medium.To evaluate the release of TMZ from the PHB-PEI nanoparticles, we incubated PHB-PEI solutions in phosphate-buffered saline at pH 7.4 and maintained them in a shaking incubator at 37°C. We recovered the TMZ from the released media by centrifugation. This procedure was repeated for five incubation times. Then the HPLC system enabled us to quantitatively determine the concentration of TMZ in the released media.The diameter of the synthesized nanoparticles and their ζ-potential was around 127nm and +8.67mV, respectively. Encapsulation efficiency and maximum drug loading of PHB-PEI nanoparticles were 47.75% and 42.44%, respectively. The release profile of TMZ from PHB-PEI nanoparticles also showed releasing of TMZ in a sustained manner with a maximum release of 2%.

Keywords:

Drug Release , Nanoparticle , PHB-PEI , Temozolomide