Banca de QUALIFICAÇÃO: MANOELA TORRES DO RÊGO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : MANOELA TORRES DO RÊGO
DATA : 29/06/2018
HORA: 09:00
LOCAL: SALA 2 DO PPGCF
TÍTULO:

Obtainment, characterization physicochemical and evaluation of antifungal activity TistH-loading cross-linked chitosan nanoparticles, one peptide identified in Tityus stigmurus scorpion

PALAVRAS-CHAVES:

Antifungal, Chitosan, Nanoparticles, Peptide TistH, Tityus stigmurus.

PÁGINAS: 118
GRANDE ÁREA: Ciências da Saúde
ÁREA: Farmácia
RESUMO:

Tityus stigmurus is a scorpion predominantly found in Northeast of Brazil and is known to produce toxins with biotechnological applications. Recently, our group identified  several bioactive peptides with pharmacological potential from the venom glands of Tityus  stigmurus through a transcriptomics approach. Among the molecules identified, one peptide like-hypotensins class (TistH, Tityus stigmurus Hypotensin), showed multifunctional  potential. Previous approach also realized by our group evidenced the TistH with bradykinin-potentiating peptide, in addition exert antifungal effect. In the present study was obtained and characterized physiochemically TistH-loading cross-linked chitosan nanoparticles for incorporation (CN-TistH-Inc) and adsorption (CN-TistH-Ads), as well as evaluated the antifungal potential. The TistH-loading cross-linked chitosan nanoparticles at 0.5 and 1.0 % were obtained by ionic gelation technique and showed positive zeta potential, size particles  less than 160 nm and polydispersity index less than 0.3. The encapsulation efficiency was greater than 95 %, confirmed by polyacrylamide gel electrophoresis and Fourier transform infrared spectroscopy that evidenced hydrophobic interactions between the peptide and the  polymer matrix. The nanoparticles analyzed by atomic force microscopy and scanning  electronic microscopy evidenced nanometric particles, spherical shape with smooth surface  and homogeneous aspects with stable colloidal dispersions for 4 months. According in vitro  release profile was observed for all formulations prolonged and sustained release for 48  hours, however with different times of initial phase of burst each nanossystem. The CN- TistH-Inc and CN-TistH-Ads 0.5 % showed a minimal inhibitory concentration (MIC) of  0.466 μg/mL against Candida albicans (ATCC 90028), while CN-TistH-Inc 0.5 % e CN-TistH-Ads 0.5 e 1.0 % showed a MIC of 0.0557 μg/mL against Candida parapsilosis (ATCC 70 22019). The TistH-loading cross-linked chitosan nanoparticles, significantly reduced the  biofilm formation of clinical yeasts sepsis of Candida tropicalis 195, C. tropicalis 447 and  C. krusei 249. Thus, this study demonstrated that chitosan nanoparticles are promising for carrying and delivering the peptides TistH from Tityus stigmurus, with antifungal activity  against genus Candida spp. may eventually be applied in the future as a possible antifungal agent.

MEMBROS DA BANCA:
Presidente - 1715308 - GUILHERME MARANHAO CHAVES
Externo ao Programa - 5329168 - EDUARDO PEREIRA DE AZEVEDO
Externo ao Programa - 021.343.914-05 - RAQUEL DE MELO BARBOSA