Thermosensitive micellar systems of PVA/PEO-PPO-PEO for photochemical nitric oxide release

Author(s)

Thatiane Cristine Camargo Marini

• Document type: Master's Dissertation
• Defense date: 2016
• Advisor: Marcelo Ganzarolli de Oliveira

Abstract

Nitric oxide (NO) is an endogenous specie present in all cells and it is involved in many biological processes. S-nitrosothiols (RSNOs) represent a class of NO donors found endogenously in mammals and it has the ability to release NO by thermal and photochemical pathways. The incorporation of those molecules in polymeric matrices can provide topical NO release controlled by irradiation with visible light. With this purpose, RSNO S-nitrosoglutathione (GSNO) was incorporated into thermosensitive nanocariers of poly (vinyl alcohol) (PVA) and triblock co polymer PEO-PPO-PEO (F127) for photochemical release of NO. Those matrices are heterogeneous systems composed of F127 micelles with hydrophobic cores of PPO, thus allowing a kinetic control of NO release in localized applications. The formulations were prepared using polymer solutions in water and were characterized as to their thermal properties such as critical micellization temperature (CMT) by differential scanning calorimetry (DSC) and micelle size and packing by small angle X-ray scattering (SAXS). The kinetics of photochemical NO release under irradiation with visible light was monitored by the decay of the GSNO band using spectrophotometer and detection of NO released in real time by chemiluminescence. The results presented in this study showed that it was possible to modulate the release of NO from the formulations varying the amounts of PVA and F127, due to changes in the properties of the solutions such as gelation temperatures and the type of micelle packing of micelles for each formulation (AU)

• FAPESP's process: 14/03266-4 - PVA-F-127 thermosensitive nanocarriers for the photochemical nitric oxide release
• Grantee: Thatiane Cristine Camargo Marini
• Support type: Scholarships in Brazil - Master