Study of photoresponsive polymeric materials for antimicrobial nitric oxide delivery

Higher VBC content enhanced reactive sites, while straight-chain amines (EDA, DETA) outperformed aromatic PPD due to reduced steric hindrance. UV-triggered release (365 - 405 nm; 15 - 35 mW cm-2) followed pseudo-first-order kinetics, with straight-chain amines enabling sustained profiles and PPD yielding rapid bursts. Release rates scaled linearly with irradiance, peaking at 385 nm aligned with the n→π* transition.<br><br>Polyethyleneimine (PEI)-functionalised N-nitrosamine donors on MCM-41, clinoptilolite, and kaolinite exhibited NO loading (θmax = 0.184 - 0.642 mmol g-1) correlated with surface area (13.6 - 320 m2 g-1) and porosity.

MCM-41 supported diffusion-limited, controlled release, whereas lower-porosity supports favoured faster surface-mediated kinetics. Optimal efficiency occurred at 385 nm, with half-lives of 1.83 - 362.90 min.<br><br>Calcium alginate hydrogels (CAH-1-3), functionalised with EDA and N-nitrosamine via oxidation, amination, and nitrosation, showed NO loading (θmax ≈ 0.03 - 0.13 mmol g-1) influenced by CaCl2 concentration (5 - 25 mg mL-1).

DCAH-1-EDA-NO demonstrated superior loading and rapid release (k ≈ 0.987 min-1 at 365 nm), while DCAH-2-EDA-NO and DCAH-3-EDA-NO exhibited slower, surface-constrained profiles. <br><br><i>Thesis is embargoed until 31 July 2029.</i>