Optimized Chitosan-Coated Gliadin Nanoparticles Improved the Hesperidin Cytotoxicity over Tumor Cells

Abstract Hesperidin is a natural compound which is found in citric fruits and presents antitumor and antimicrobial activities. However, the in vivo efficacy of Hesperidin is reduced due to its low oral bioavailability. Protein-based nanoparticles have been applied to improve biological parameters of drugs and natural compounds. Gliadin is a monomeric protein present in wheat. In this study, gliadin-based nanoparticles containing hesperidin were obtained by desolvation technique and a Taguchi orthogonal array design was employed to optimize the formulation. The independent variables were set as concentration of CaCl2 (0.5; 1 or 2%) and stabilizing agent (Pluronic F68, Tween 80 or sodium caseinate). The dependent variables consisted of mean diameter, polydispersity index, zeta potential, and encapsulation efficiency. The results showed significant effects on the dependent variables when 1% CaCl2 and Pluronic F68 were used. The optimized formulation was coated with chitosan to increase the physical stability of the nanoparticles. The final nanoparticles presented a mean diameter of 321 nm and polydispersity index of 0.217, and spherical shape. After coating, the Zeta potential was +21 mV, and the encapsulation efficiency was 73 %. The in vitro release assay showed that about 98% of the drug was released from the nanoparticles after 48 h. Moreover, the nanoparticles reduced hesperidin cytotoxicity on healthy cells (Vero cells) and improved the cytotoxicity on tumor cells (HeLa, PC-3 and Caco-2 cells). Results showed that the chitosan-coated gliadin nanoparticles are potential carriers for hesperidin delivery for cancer treatment.

Development of chitosan nanocapsules containing essential oil of Matricaria chamomilla L. for the treatment of cutaneous leishmaniasis.

Matricaria chamomilla L. has been used for centuries in many applications, including antiparasitic activity. Leishmaniasis is a parasitic disease, with limited treatments, due to high cost and toxicity. Thus, there is a need to develop new treatments, and in this context, natural products are targets of these researches. We report the development of chitosan nanocapsules containing essential oil of M. chamomilla (CEO) from oil-in-water emulsions using chitosan modified with tetradecyl chains as biocompatible shell material. The nanocapsules of CEO (NCEO) were analyzed by optical microscopy and dynamic light scattering, which revealed spherical shape and an average size of 800 nm. Successful encapsulation of CEO was further confirmed by fluorescence microscopy observations taking advantage of the autofluorescence properties of CEO. The encapsulation efficiency was around 90%. The entrapment of CEO reduced its cytotoxicity towards normal cells. On the other hand, the CEO was active against promastigotes and intracellular amastigotes, exhibiting IC50 of 3.33 µg/mL and 14.56 µg/mL, respectively, while NCEO showed IC50 for promastigotes of 7.18 µg/mL and for intracellular amastigotes of 14.29 µg/mL. These results demonstrate that encapsulation of CEO in nanocapsules using an alkylated chitosan biosurfactant as a "green" stabilizer is a promising therapeutic strategy to treat leishmaniasis.

Tamoxifen-loaded poly(L-lactide) nanoparticles: Development, characterization and in vitro evaluation of cytotoxicity.

In this study, poly(L-lactide) (PLA) nanoparticles containing Tamoxifen (Tmx) were developed using an emulsion/solvent evaporation method, observing the influence of surfactants and their concentrations on mean particle size and drug entrapment. Nanoparticles were characterized in terms of size, morphology, polydispersity, interaction drug-polymer and in vitro drug release profile. Cytotoxicity over erythrocytes and tumor cells was assessed. The optimized formulation employed as surfactant 1% polyvinyl alcohol. Mean particle size was 155±4 nm (n=3) and Tmx encapsulation efficiency was 85±8% (n=3). The in vitro release profile revealed a biphasic release pattern diffusion-controlled with approximately 24% of drug released in 24 h followed by a sustained release up to 120 h (30% of Tmx released). PLA nanoparticles containing Tmx presented a very low index of hemolysis (less than 10%), in contrast to free Tmx that was significantly hemolytic. Tmx-loaded PLA nanoparticles showed IC50 value 2-fold higher than free Tmx, but considering the prolonged Tmx release from nanoparticles, cytotoxicity on tumor cells was maintained after nanoencapsulation. Thus, PLA nanoparticles are promising carriers for controlled delivery of Tmx with potential application in cancer treatment.

Bovine Serum Albumin Nanoparticles Containing Amphotericin B: Characterization, Cytotoxicity and In Vitro Antifungal Evaluation.

In this study, nanoparticles based on bovine serum albumin (BSA) containing amphotericin B (AmB) were obtained by the desolvation method and characterized with respect to size, size distribution, AmB encapsulation efficiency, AmB state of aggregation, and AmB in vitro release profile. After, the effect of nanoparticles on the cytotoxicity of human erythrocytes in vitro and efficacy over strains of Candida spp. were evaluated. The mean particle size was 156 nm and the AmB encapsulation efficiency was over 82%. The in vitro release profile revealed a sustained release of approximately 48% of AmB over 5 days. AmB is present in BSA nanoparticles as monomer. AmB-loaded nanoparticles showed very low index of hemolysis (less than 8%) in 72 h of assay compared to free AmB, which presented 100% of hemolysis in 2 h of incubation. The AmB-loaded BSA nanoparticles were as effective as free AmB against Candida albicans and Candida tropicalis, considering their sustained release profile. Thus, BSA nanoparticles are potential carriers for AmB, reducing its molecular aggregation and prolonging its release, resulting in lower cytotoxicity while maintaining its antifungal activity.

Efeito da nicotina sobre fagócitos ativados / Effect of the nicotine on actived phagocytes

Indivíduos fumantes apresentam aumento na proporção de leucócitos polimorfonucleares (LPMN), como por exemplo, no tecido pulmonar, resultando em aumento nos níveis de enzimas proteolíticas e espécies reativas de oxigênio, que ocasionam efeito destrutivo na matriz celular e contribuem para a progressão da doença pulmonar, além de favorecer o aparecimento de infecções microbianas, e determinam que as células fagocíticas estejam em frequente estado de ativação (fagocitose). Neste trabalho, avaliou-se a influência da nicotina (NIC) sobre a viabilidade de LPMN e macrófagos ativados ou não, pelos estímulos zymosan e acetato de forbol miristato. Os resultados indicaram que a NIC promove aumento na viabilidade de LPMN e macrófagos ativados em relação a essas células ativadas sem a presença de NIC, avaliada 'ex vivo' pelo teste de exclusão do azul de trypan. Esse efeito foi significativamente mais pronunciado sobre LPMN que sobre os macrófagos. Essa redução na citotoxicidade favorece a sobrevida da célula, podendo exacerbar os seus efeitos deletérios, especialmente em no seu estado ativado, pela maior produção de espécies reativas de oxigênio.

Smokers show increased rates of polymorphonuclear leukocytes (PMNL), including in pulmonary tissue, resulting increased levels of proteolytic enzymes and reactive oxygen species, which have a destructive effect on the cellular matrix and contribute to the progression of pulmonary disease, in addition to promoting the onset of microbial infections which cause phagocytic cells to be in a state of frequent activation (phagocytosis). This work evaluated the influence of nicotine (NIC) on the viability of PMNL and macrophages (activated or not), by stimuli zymosan and phorbol myristate acetate. The results indicated that NIC led to increased viability of PMNL and activated macrophages compared to these cells activated without NIC, measured ex vivo by trypan blue exclusion test. This effect was significantly higher on PMNL than on macrophages. This reduction in cytotoxicity favors cell survival, and may exacerbate its deleterious effect, especially in the active state, due to increased production of reactive oxygen species.