Banca de DEFESA: VALDEMIR DA COSTA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : VALDEMIR DA COSTA SILVA
DATE: 27/04/2023
TIME: 14:00
LOCAL: virtual
TITLE:

DEVELOPMENT AND CHARACTERIZATION OF POLYMERIC MEMBRANES ASSOCIATED WITH RED PROPOLIS AND ALLOIN 

KEY WORDS:

Keywords: Propolis; Aloe; Polymers; Biological dressings; Antioxidant activity.

PAGES: 117
BIG AREA: Multidisciplinar
AREA: Biotecnologia
SUBÁREA: Biotecnologia em Recursos Naturais
SUMMARY:

Chronic skin lesions, such as burns, ulcers or other traumatic injuries, represent a health problem that affects millions of people around the world and causes strong social and economic damage. In the last twenty years, biocompatible, biodegradable, and bioabsorbable polymers are the most used for the development of membranes for wound healing. Natural polymers such as sodium carboxymethylcellulose (CMC-Na) and pectin are carriers of bioactive compounds and have a high swelling capacity. The incorporation of natural products such as red propolis and aloin in membranes is a relevant strategy to enhance wound healing. Red propolis and aloin have several biological activities, such as antioxidant, healing, anti-inflammatory and tissue repair. Thus, the present work aimed to develop and characterize polymeric membranes associated with red propolis and/or aloin. Extraction by maceration was used to obtain the hydroalcoholic extract of red propolis at 30% (w/v). The membranes (membrane + red propolis - MPV; membrane + aloin - MALO and membrane + red propolis + aloin - MPVALO) were obtained with a previous preparation of a carboxymethylcellulose and pectin gel, followed by the association of the hydroalcoholic extract of red propolis and/ or aloin. The extracts and polymeric membranes were evaluated to obtain the phytochemical profile by UPLC-DAD, the antioxidant activity by DPPH methods and by FRAP (Ferric Reducing Antioxidant Power). The determination of total phenols and flavonoids was performed by the colorimetric method of Folin-Ciocalteau and aluminum chloride, respectively. Membranes associated with red propolis and aloin were evaluated for their decomposition and compatibility by thermogravimetric analysis, differential scanning calorimetry and Fourier transform infrared spectroscopy. Membrane morphology was obtained by scanning electron microscopy. The degree of swelling and the release profile were determined in saline solution. The extracts and membranes were evaluated for antimicrobial activity by determining the minimum inhibitory concentration (MIC) and cell viability in L929 fibroblast lineage. The polymeric membranes presented similar macroscopic morphological characteristics such as: uniformity, flexibility, and resistance to handling. The chromatographic method allowed the identification of chemo markers of red propolis and aloin A and B. Phenolic compounds contents of 174.2 ± 2.0 and 79.1 ± 2.5 mgGAE g were respectively found in the red propolis and aloin extract -1 and total flavonoids of 46.2 ± 3.2 and 9.9 ± 3.7 mgQE g^-1. The combined extracts showed high antioxidant activity: 91.2 ± 2.7% (red propolis extract) and 63.1 ± 2.5% (aloin) by the DPPH method and iron reducer. Membranes loaded with extracts showed reduced antioxidant activity. Thermal analysis of the membranes by differential scanning calorimetry and infrared spectroscopy by Fourier transform revealed the homogeneity of the membrane with red propolis and aloin. MPVALO showed less homogeneity and greater thermal stability. The morphological assay revealed that the membranes had a smooth surface with foci of depression. The association of red propolis and aloin accelerates swelling and decreases the stability of the polymeric chain. Polymeric membranes release approximately 60% of the incorporated extract within 48 hours. The extracts and the association of red propolis + aloin showed relevant antimicrobial activity against the Staphylococcus aureus strain. MPVALO showed greater halo formation against gram-positive bacteria. MALO showed cytotoxicity (125 µg/mL) and MPVALO showed 99.6% preservation of fibroblasts at a concentration of 125 µg/mL. On this context, it is possible to state that MPVALO is an important biodegradable, non-cytotoxic product, capable of forming a physical barrier, promoting the absorption of exudate and release of phenolic compounds with antioxidant and antimicrobial activities.

BANKING MEMBERS:
Presidente - 2120103 - MARILIA OLIVEIRA FONSECA GOULART
Interno(a) - 426640 - FABIANE CAXICO DE ABREU GALDINO
Interno(a) - 1247925 - ANIELLE CHRISTINE ALMEIDA SILVA
Externo(a) ao Programa - 1553302 - IRINALDO DINIZ BASILIO JUNIOR
Externo(a) ao Programa - 1820117 - ISIS MARTINS FIGUEIREDO
Externo(a) ao Programa - 1006306 - JADRIANE DE ALMEIDA XAVIER
Externo(a) à Instituição - MARIA APARECIDA MEDEIROS MACIEL - UnP
Externo(a) à Instituição - GUSTAVO BRAGA - UFMA