Wanyiu Fok

Year of Award


Degree Type


Degree Name

Master of Philosophy (MPhil)


Department of Biology.

Principal Supervisor

Mak, Naiki


Cancer ; Magnetic resonance imaging ; Photochemotherapy ; Porphyrins ; Treatment




Photodynamic therapy (PDT) and Magnetic resonance imaging (MRI) are two techniques used in therapeutic and diagnostic purpose respectively. PDT can selectively kill the cancer cells by utilizing light and photosensitizer, while MRI provides invasive imaging on our interior bodies. If these two techniques combine, the probe can act as both PDT and MRI agent at the same time. This theranostic agents can bring great efficiency in the cancer treatment. In this project, a porphyrin-cyclen gadolinium based dual functions bio-probe, PZnGdL, is designed for diagnostic and photodynamic therapeutic functions. PZnGdL demonstrated a great T1 signal enhancement for MRI, in which its T1 relaxivity is 15.06 mM-1s-1 (at 1.4T, 37oC). The T1 relaxivity is five-fold higher than the clinically approved MRI contrasting agent Gd-DOTA, (2.92 at 1.4T, 37oC). Furthermore, PZnGdL exhibits low dark toxicity and high photocytotoxicity. Therefore, its photodynamic therapeutic index (PDI) in HeLa cells is as high as 1348 upon 1 J/cm2 light irradiation. Results from the present study show that PZnGdL is an effective photodynamic therapy agent as well as a safe and promising MRI contrasting agent.


Principal supervisor: Professor Mak Nai Ki ; Thesis submitted to the Department of Biology ; Thesis (M.Phil.)--Hong Kong Baptist University, 2019.


Includes bibliographical references (pages 85-92).

Available for download on Sunday, October 17, 2021