Preparação e caracterização de nanocarreadores de anfotericina B à base de goma do cajueiro hidrofobizada com anidridos propiônico e butírico

• Ano de defesa: 2019
• Autor(a) principal: Richter, Ana Rosa
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Goma do cajueiro; Nanopartículas; Anfotericina B
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/43777

The aim of this work was to prepare nanocarriers by self-assembly and Pickering emulsions from acylated cashew gum (CG), using propionic and butyric anhydrides, named GCAc, GCProp and GCBut, for Amphotericin B (AmB) encapsulation. The reaction was performed in three CG/anhydrides molar ratio conditions (1:9, 1:12 and 1:24) and the acylation reaction was confirmed by FTIR and NMR spectra. The degree of substitution was measured by potenciometric titration and it increases with increasing of anhydride amount for GCAc and GCBut derivatives. TGA analysis showed the acylation provides a better thermal stability in comparison with GC. Zebrafish toxicity showed biocompatibility for GCProp and GCBut. Nanoparticles (NP´s) with monomodal size distribution, very negative zeta potential and low PDI were produced. SEM showed a smooth and spherical surface for nanoparticles. Pickering emulsions were prepared by adding the organic phase in the aqueous phase, resulting the immediate emulsion formation. The particle size of emulsion presented unimodal distribution and a size decrease is observed after the isolation by centrifugation. The atomic force microscopy confirmed the hypothesis that nanoparticles are around the oil drop. After AmB encapsulation there is an increase in particle size, decrease PDI and zeta potential for NP´s and emulsions. The efficiency of encapsulation (EE) was higher for NP´s (maximum EE = 96.3 ± 4.6%) than for nano emulsions (maximum EE = 55.2 ± 0.1%), however AmB is less aggregated in the emulsion system. Two stability assays were performed for NP's and Pickering emulsions and, in both assays, the two systems had excellent stability. The GCProp loaded AmB exhibited best size stability over 180 days. The in vitro release profile of AmB for the NPs had its maximum release of 61.06 ± 1.4% after 72 h of assay. The hemolysis assay showed that the GCProp 9 emulsion shows a small extent of damage to the erythrocytes, indicating a system with good compatibility.