Near-infrared light for phototherapy : photothermal induced drug release and tumor ablation

• Main Author: Li, Menghuan
• Other Authors: Zhao Yanli
• Format: Theses and Dissertations
• Language: English
• Published: 2015
• Subjects: DRNTU::Science::Medicine::Pharmacy; DRNTU::Science::Medicine::Biomedical engineering
• Online Access: http://hdl.handle.net/10356/65741
• Institution: Nanyang Technological University

Since the introduction of nanotechnology into cancer treatment, numerous therapeutic nanoagents have been developed for the detection, imaging and therapy of various types of cancers. Amongst all these efforts, near-infrared-light-involved anticancer therapy has drawn increasing attention in recent years, due to the minimal invasiveness and high tissue penetration of near-infrared light (NIR). This thesis will focus on the utilization of NIR light in anticancer therapy in combination with inorganic and organic NIR-responsive photothermal agents, of which could absorb the incoming NIR irritation and transform it into thermal energy. The temperature escalation is used to initiate the release of anticancer drugs from the nanocarrier or directly destroy the cancer cells. The studies listed in this thesis made a robust investigation into the potential application of NIR-driven therapeutic nanoplatforms and showed inspiring results both in vitro and in vivo. Gold nanorods are one of the many types of anisotropic metallic nanoparticles used in biomedical research. With their highly achievable monodispersity and manipulable aspect ratio, the optical absorption wavelength of gold nanorods could be precisely controlled within the biological window of living tissues, which is ideal for controllable and efficient photothermal heat generation. Chapter 2 introduces a stimuli-responsive drug delivery system using a single gold nanorod as the core compartment. The hydrophilic anticancer drug doxorubicin was encapsulated using ultraviolet irritation and could be released in response to NIR illumination. Its controllable drug release behaviour has been further investigated in vivo in live zebrafish embryo models. Polymer chemistry is one of the most important sub-branches of modern chemistry that is closely related to our daily life. It could provide us with products at various sizes with unique physical and chemical properties. Chapter 3 describes one of my attempts to combine the specifically functionalized polymer with gold nanorods for a controllable drug delivery system. A pH/temperature dual responsive polymer shell was conjugated onto the gold nanorods for the drug encapsulation and delivery. Though the eventual outcome is not satisfactory, it still provided some inspirations for my follow-up research. The lessons learnt from the dual responsive core/shell drug nanocarrier proved substantial, which offered useful insights for the shaping of a new NIR responsive drug delivery system. To overcome those problems that are persistent to the organic/inorganic hybrid nanoparticles such as low cellular uptake and morphological uniformity, a new organic photothermal agent IR825 was used with thermoresponsive liposomal formulations. The structural characterizations and therapeutic efficacy were introduced in Chapter 4. My studies of these NIR responsive therapeutic nanoplatforms presented a variety of applications based on nanomaterials that were capable of photothermal heat generation. Collectively these studies provided robust insights on the application of NIR laser in cancer treatment, as well as expanded our knowledge of nanotechnology in drug delivery research.