Defense Date

2010

Document Type

Thesis

Degree Name

Master of Science

Department

Biomedical Engineering

First Advisor

HU Yang

Abstract

A novel amphiphilic core-corona hyperbranched polymer, composed of 3-ethyl-3-(hydroxylmethyl) oxetane (EHMO) and PEGylated EHMO (EHMOPEG), was synthesized through cationic ring opening polymerization. Nuclear Magnetic Resonance spectroscopy (NMR), Dynamic Light Scattering (DLS), and Fourier Transform Infrared spectroscopy (FTIR) were used to characterize the polymer structure and degree of branching. It was found that the degree of branching (DOB) of the polymer was affected by the weight % ratios of EHMO/EHMOPEG used in polymerization. As the weight % ratio of EHMO/ EHMOPEG decreased, the DOB was observed to increase. Polymeric particles based on the synthesized polymer were prepared using the O/W (Oil in Water) solvent emulsion method and evaluated for drug delivery. Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS) were used to characterize the size and shape of the particles. The obtained particles were found to be spherical in shape and have a narrow size distribution. Camptothecin (CPT) was used as the model drug for drug encapsulation and controlled release studies. The loading and encapsulation efficiencies of the particles ranged between 60% and 80%. Cytotoxicity studies carried out with human skin fibroblasts indicated that as the weight % ratio of the EHMO/ EHMOPEG decreased the biocompatibility of the polymer increased. In vitro drug release studies showed that the CPT could be released over an extended period of time. The efficacy of the drug released from the particles was demonstrated by the MTT assay on HN12 cells. The results showed that the cellular activity decreased as the amount of drug released from the particles increased over a span of 72 hours. The synthesized polymer represents a new family of hyperbranched macromolecule with potential for drug delivery.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

July 2010

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