Ameliorating the antiparasitic activity of the multifaceted drug ivermectin through a polymer nanocapsule formulation

Ivermectin (IVM) is a potent antiparasitic widely used in human and veterinary medicine. However, the low oral bioavailability of IVM restricts its therapeutic potential in many parasitic infections, highlighting the need for novel formulation approaches. In this study, poly(ε-caprolactone) (PCL) nanocapsules containing IVM were successfully developed using the nanoprecipitation method. Pumpkin seed oil (PSO) was used as an oily core in the developed nanocapsules. Previously, PSO was chemically analyzed by headspace solid-phase microextraction coupled to gas chromatography/mass spectrometry (HS-SPME/GC-MS). The solubility of IVM in PSO was found to be 4,266.5 ± 38.6 μg/mL. In addition, the partition coefficient of IVM in PSO/water presented a logP of 2.44. A number of nanocapsule batches were produced by factorial design resulting in an optimized formulation. Negatively charged nanocapsules measuring around 400 nm demonstrated unimodal size distribution, and presented regular spherical morphology under transmission electron microscopy. High encapsulation efficiency (98-100%) was determined by HPLC. IVM-loaded capsules were found to be stable in nanosuspensions at 4°C and 25°C, with no significant variations in particle size observed over a period of 150 days. Nanoencapsulated IVM (0.3 mM) presented reduced toxicity to J774 macrophages and L929 fibroblasts compared to free IVM. Moreover, IVM-loaded nanocapsules also demonstrated enhanced in vitro anthelmintic activity against Strongyloides venezuelensis in comparison to free IVM. Collectively, the present findings demonstrate the promising potential of PCL-PSO nanocapsules to improve the antiparasitic effects exerted by IVM.

Levan-based nanostructured systems: An overview

Bacterial levan is a fructose homopolymer that offers great potential in biotechnological applications due to biocompatibility, biodegradability and non-toxicity. This biopolymer possesses diverse multifunctional features, which translates into a wide range of applicability, including in industry, consumer products, pharmaceuticals and biomedicine. Extensive research has identified great potential for its exploitation in human health. In addition, nanostructured systems have provided significant advances in the area of health, mainly with respect to disease diagnosis and treatment. While the functional properties of these natural polysaccharide-based polymers are desirable in these systems, research in this area has been limited to few natural polymers, such as chitosan, alginate and dextran, which obscures the true potential of levan in the production of nanostructured systems for biotechnological and medical applications. The present review considers the latest research in the field to focus on the use of levan as a promising biopolymer for the development of nanomaterials.

Portulaca elatior root contains a trehalose-binding lectin with antibacterial and antifungal activities

Lectins are carbohydrate-binding proteins broadly distributed in plants and have several biological functions, including antimicrobial action. Portulaca elatior is a Caatinga plant whose chemical composition and biotechnological potential have not been extensively studied. In this work, a lectin was isolated from P. elatior root extract and evaluated for antimicrobial activity. The P. elatior root lectin (PeRoL) showed native molecular mass of 33 kDa, pI 3.8 and is comprised of two subunits of 15 kDa linked by disulfide bonds. No sequence similarities with Viridiplantae proteins were observed. The PeRoL hemagglutinating activity (HA) was not affected by heating and was detected in a pH ranging from 4.0 to 8.0. Trehalose was identified as an endogenous inhibitor of PeRoL present in the roots. Bacteriostatic activity was detected against Enterococcus faecalis, Pseudomonas aeruginosa and Staphylococcus aureus (minimal inhibitory concentration of 8.1, 32.5 and 4.06 μg/mL, respectively). PeRoL induced the death of Candida albicans, Candida parapsilosis, Candida krusei, and Candida tropicalis cells, with a minimal fungicidal concentration of 16 μg/mL. The lectin (100 μg/mL) was not cytotoxic to human peripheral blood mononuclear cells (PBMCs) and did not show hemolytic activity. In conclusion, the roots of P. elatior contain a trehalose-binding, thermostable, and antimicrobial lectin.

Microwave-assisted hydrolysis of Zymomonas mobilis levan envisaging oligofructan production

Levan, a polysaccharide from Zymomonas mobilis, was hydrolyzed to obtain oligofructans or fructooligosaccharides with a degree of polymerization varying from 4 to 14. Fructooligosaccharides (FOS) are short chain fructans that beneficially affects the host by selective stimulation of growth and activity of one or a number of bacteria including probiotic bacteria in the colon. The hydrolysis was performed in a microwave oven to shorten the reaction time. The experiments showed that it is possible to maximize selected oligomers by interrupting the hydrolysis at the due time. The results allow one to infer that the procedure may also be useful for production of oligomers from other polysaccharides.

Avaliação dos riscos associados ao uso do xilol em laboratórios de anatomia patológica e citologia

Neste estudo, realizou-se uma avaliação do risco ocupacional relacionado ao uso de xilol, ao qual estão expostos técnicos de oito laboratórios de citologia e anatomia patológica que atendem a população do Recife e de cidades do interior de Pernambuco. A coleta das informações deu-se por meio de questionários que podiam ser respondidos marcando-se alternativas de múltipla escolha. Deu-se destaque às informações decorrentes do uso do xilol relacionadas à saúde ocupacional e à percepção de risco na manipulação e no descarte dos rejeitos. Os resultados mostraram que a utilização de equipamentos de proteção individual e coletiva está sendo negligenciada. Dentre os entrevistados, 80% observaram mudanças na saúde após alguns anos de exposição ao xilol. Mesmo assim, apenas 6,6% deles fazem controle anual da presença de xilol no organismo pela dosagem de ácido metilhipúrico na urina. Constatou-se que 76,6% dos entrevistados descartam o resíduo diretamente na pia, pois não existe um local para descarte de rejeitos. Frente aos dados encontrados, sugere-se que há necessidade de educar o trabalhador numa visão prevencionista em relação aos riscos ocupacionais e ambientais provenientes do uso deste agente químico.