Preparation of biodegradable lipid-based indocyanine green J-aggregate nanoparticles for photothermal therapy

  • Hamoud Alotaibi

Student thesis: Doctoral ThesisThesis with Publications

Abstract

Photothermal therapy (PTT) is a minimally invasive cancer treatment that employs light-absorbing agents to convert near-infrared (NIR) light into heat, selectively destroying cancer cells. The use of biodegradable agents such as indocyanine green J-aggregate (IJA) offers a promising alternative to nonbiodegradable materials like gold nanoparticles (NPs). However, the scalability and development of IJA face challenges, including poor optical stability in aqueous and biological environments, short in vivo circulation with rapid dissociation, and sensitivity to formulation parameters such as solvent, temperature, and surfactants. This thesis focuses on engineering multifunctional biodegradable lipid-based systems loaded with pre-formed IJA (p-IJA) as a PTT agent. First, p-IJA-loaded liposomes were developed using the lipid film hydration method, and their physicochemical properties and thermal activity were evaluated. Rigid lipid (DSPC), cholesterol (50% mol), and PEGylation significantly enhanced p-IJA stability, leading to nano-sized formulations (>200 nm) with superior heating capacity. Next, the role of lipid nanocapsule (LNC) shells in stabilising p-IJA was studied. Formulation parameters such as surfactant type (hydrophilic, hydrophobic, and cationic), temperature, and particle size were optimised. The addition of Span 85 and DOTAP to the LNC shell enhanced stability and improved the IJA ratio. Finally, the solidification of lipid nanoparticles using solid lipid nanoparticle (SLN) cores was explored. High melting point lipids, such as sodium stearate, enhanced p-IJA-SLN heating capacity during single and multiple heating cycles. This work demonstrates that p-IJA loaded into lipid-based systems achieves superior thermal activity, stability, and scalability, offering a promising platform for advancing PTT applications.

Thesis is under embargo until 31 July 2028.


Date of AwardJul 2025
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SponsorsNorthern Border University
SupervisorWafa Al-Jamal (Supervisor), Taher Hatahet (Supervisor) & Vicky Kett (Supervisor)

Keywords

  • liposomes
  • photothermal therapy
  • PTT
  • indocyanine green j-aggregates

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