DESENVOLVIMENTO TECNOLÓGICO E CARACTERIZAÇÃO DE LIPOSSOMAS CARREGADOS COM NANOPARTICULAS DE PRATA OBTIDAS POR SÍNTESE VERDE

Abstract

Silver nanoparticles (AgNPs) are known for their antimicrobial and antitumor activities. Another compound of great interest is Lupeol, a pentacyclic triterpene, with therapeutic and chemopreventive activities for the treatment of infections and cancer. Thus, biocompatible and biodegradable liposomes are presented as a carrier capable of transporting these two compounds. The objective of this work was to develop and characterize liposomes, loaded with silver nanoparticles containing cholesterol (LAgNPs) or lupeol (LUNP) in their lipid bilayer. AgNPs were prepared by the green synthetic method with exposure to sunlight and the liposomes were prepared by the modified reverse phase method. Particle size, polydispersity index, zeta potential, as well as morphological aspects were determined by scanning electron microscopy (SEM-FEG) and X-ray diffraction of AgNPs and liposomes. In addition, an analytical method has been developed and validated by flame atomic absorption spectroscopy to determine the amount of silver that has been encapsulated in liposomes. The AgNPs presented as amorphous, polydisperse structures, with mean diameter between 278.46 nm and zeta potential of -18,3 mV . LAgNPs had a mean diameter between 321 and 373 nm, the polydispersity index close to 0.2 and a zeta potential around -40 mV, indicative of low polydispersity and which gives greater stability to AgNPs. It was possible to obtain liposomes containing lupeol in their lipid bilayer, loading silver nanoparticles (LUNP) with a mean diameter of 218.8 nm, zeta potential of -36.5 mV and polydisperse sizes. The images obtained by FEG show semicircular structures for AgNPs and spherical for well-defined LAgNPs and LUNPs. The analytical method to quantify silver nanoparticles was developed and validated, showing linear, precise and exact, which allowed to determine the percentage of encapsulation being between 51.81 to 58.83% for LAgNP and 56.08% for LUNP . These results showed that LAgNPs were obtained with adequate physicochemical characteristics as a release system, with potential antimicrobial and / or antitumor action, as an alternative to conventional treatments.