published_or_final_version / abstract / toc / Pathology / Doctoral / Doctor of Philosophy

It has been demonstrated that 1,25 dihydroxy vitamin D3 (1,25 (OH)2VD3) can inhibit the proliferation of cancer cells including colorectal and hepatocellular cells which are mainly responsible for liver cancer. However, the use of 1, 25 (OH)2VD3 is hampered due to the development of hypercalcaemia. Current treatment using hepatic arterial delivery of drug solution is inconvenient since repetitive invasive treatments are required. This work aims to tackle this problem by utilizing crosslinked microspheres prepared by suspension polymerization as a carrier to control the release of 1, 25 (OH)2VD3 or hydrophobic drug in general at targeted sites over a long period. Poly(vinyl neodecanoate crosslinked ethyleneglycol dimethacrylate) microspheres in the size range of 35 m were prepared via suspension polymerization. Different parameters in suspension polymerization such as temperature, concentration and crosslinker percentage were studied in details. The effect of stabilizer on the formation of spheres was carefully investigated by using RAFT polymerization to produce various structures of the stabilizer, poly (vinyl pyrrolidone). Core- shell microspheres were also produced to enhance the hydrophilicity of the surface of microspheres. Hydrophobic drugs were loaded to these microspheres after reaction by the evaporation method. These microspheres were then used for drug loading and drug release study. Release study has shown that up to 10% of drug was released after 40 days. Cytotoxicity test reveals the suitability of this polymer for application in biomedical field. The MTT assay of Clofazimine loaded microspheres on the colorectal cancer cell lines HT29 has shown that the cell number was decreased about 50% after drug treatment.

It has been demonstrated that 1,25 dihydroxy vitamin D3 (1,25 (OH)2VD3) can inhibit the proliferation of cancer cells including colorectal and hepatocellular cells which are mainly responsible for liver cancer. However, the use of 1, 25 (OH)2VD3 is hampered due to the development of hypercalcaemia. Current treatment using hepatic arterial delivery of drug solution is inconvenient since repetitive invasive treatments are required. This work aims to tackle this problem by utilizing crosslinked microspheres prepared by suspension polymerization as a carrier to control the release of 1, 25 (OH)2VD3 or hydrophobic drug in general at targeted sites over a long period. Poly(vinyl neodecanoate crosslinked ethyleneglycol dimethacrylate) microspheres in the size range of 35 m were prepared via suspension polymerization. Different parameters in suspension polymerization such as temperature, concentration and crosslinker percentage were studied in details. The effect of stabilizer on the formation of spheres was carefully investigated by using RAFT polymerization to produce various structures of the stabilizer, poly (vinyl pyrrolidone). Core- shell microspheres were also produced to enhance the hydrophilicity of the surface of microspheres. Hydrophobic drugs were loaded to these microspheres after reaction by the evaporation method. These microspheres were then used for drug loading and drug release study. Release study has shown that up to 10% of drug was released after 40 days. Cytotoxicity test reveals the suitability of this polymer for application in biomedical field. The MTT assay of Clofazimine loaded microspheres on the colorectal cancer cell lines HT29 has shown that the cell number was decreased about 50% after drug treatment.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaves 142-158) Also available in print.

published_or_final_version / abstract / Surgery / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Clinical Oncology / Doctoral / Doctor of Philosophy

published_or_final_version / Surgery / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Surgery / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Surgery / Master / Master of Philosophy