Banca de QUALIFICAÇÃO: ANDERSON FERREIRA SEPÚLVEDA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ANDERSON FERREIRA SEPÚLVEDA
DATA : 12/11/2020
HORA: 14:00
LOCAL: UFABC, Campus Santo André
TÍTULO:

Poloxamer-hyaluronic acid thermosensitive hydrogel: influence of supramolecular structure on drug release kinetics

PÁGINAS: 100
GRANDE ÁREA: Ciências Biológicas
ÁREA: Farmacologia
RESUMO:

Hydrogels have been used as materials for pharmaceutical and cosmetic purposes, due to their ability to control the release of drugs and their low toxicity, reducing the frequency of administrations and the potential for toxicity. Some of these materials are formed by temperature-responsive triblock copolymers called poloxamers (PL) which, in an aqueous medium, form micelles with the ability to self-aggregate depending on the temperature, acquiring a gel aspect with different structural organizations. This work aims to describe the physical-chemical and mechanical characteristics of hydrogels based on PL407 and / or 338 (15 to 30%) and their associations with hyaluronic acid (0.5%), containing the local anesthetics bupivacaine (BVC) or ropivacaine (RVC) 0.5%. Hydrogels were characterized in terms of morphology by Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), Differential Explanatory Calorimetry (DSC), Rheology and Low Angle Neutron Scattering (SANS). Simulations in a “coarse-grained” model were performed to study the interaction between polymers and drugs. The in vitro release tests were performed to characterize and determine the drug release constants from each formulation. DLS analyzes showed that the micellar dimensions were not changed after the incorporation of drugs or HA. However, the structural organization of hydrogels was modified by possible hydrophobic interactions (caused by BVC or RVC) or by hydrophilic interactions (caused by PL 338 or HA), as verified by calorimetric analyzes. These changes in structures reflect the organization of the polymeric networks and the viscoelastic characteristics of the gel. The SANS results confirm that all formulations containing PL 407 15% had lamellar structures, as expected for hydrogels with low polymeric concentration. For PL 407 30% and PL 407 15% + PL 338 15%, cubic and hexagonal structures were identified, justifying the higher viscosity and consistency of the material. In addition, the addition of BVC, RVC or HA interferes with the structuring of supramolecular organizations by enhancing interactions between components, except for formulations PL 407 15% + PL 338 15%. For these formulations, it is observed that the internal organization and the dimensions of the structures are not affected by the temperature or addition of additive. As the simulations showed, the binary systems are formed by micelles composed exclusively of PL 407 and PL 338 at 25 ° C and 37 ° C, which can reflect on the stability of the system. Both PL 407 30% and PL 407 15% + PL 338 15% showed similar patterns of drug release, but the addition of HA in the binary system proved to be more efficient to modulate the release of BVC or RVC.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1563992 - ANA LÍGIA SCOTT
Membro Titular - Examinador(a) Externo ao Programa - 1762438 - JEAN JACQUES BONVENT
Membro Titular - Examinador(a) Externo à Instituição - LEANDRO RAMOS SOUZA BARBOSA - USP
Membro Suplente - Examinador(a) Interno ao Programa - 3066269 - VINICIUS DE ANDRADE OLIVEIRA
Membro Suplente - Examinador(a) Interno ao Programa - 1675708 - DANIELE RIBEIRO DE ARAUJO
Membro Suplente - Examinador(a) Externo à Instituição - CÍNTIA MARIA SAIA CEREDA