ABSTRACT
Poly-ε-caprolactone (PCL) is a biodegradable polyester that has FDA and CE approval as a medical device. Nonetheless, the lack of toxicity exhibited by the polymer cannot be extrapolated to its nanomaterial conformation. Despite PCL-based NPs being widely studied in the biomedical field for their advantages as controlled drug delivery systems, little data describe PCL NPs' toxicity, particularly immunotoxicity. This work assessed different PCL-based delivery systems intended for protein delivery regarding their immunotoxicity and hemocompatibility. Two different molecular weight PCL polymers were used, as well as blends with chitosan and glucan. Results showed that the presence of NaOH during the production of PCL2 NPs and PCL2/glucan NPs induced PCL alkali hydrolysis, generating more reactive groups (carboxyl and hydroxyl) that contributed to an increased toxicity of the NPs (higher reduction in peripheral blood mononuclear cell viability and lower hemocompatibility). PCL2/glucan NPs showed an anti-inflammatory activity characterized by the inhibition of LPS stimulated nitric oxide (NO) and TNF-α. In conclusion, generalizations among different PCL NP delivery systems must be avoided, and immunotoxicity assessments should be performed in the early stage of product development to increase the clinical success of the nanomedicine.
Subject(s)
Nanoparticles/chemistry , Polyesters/chemistry , Animals , Cell Line , Cell Survival/drug effects , Cytokines/biosynthesis , Humans , Hydrolysis , Mice , Molecular Weight , Nitric Oxide/biosynthesis , Particle Size , Polyesters/pharmacology , RAW 264.7 Cells , Reactive Oxygen Species/metabolismABSTRACT
Polylactic acid (PLA), a biodegradable and biocompatible polymer produced from renewable resources, has been widely used as a nanoparticulate platform for antigen and drug delivery. Despite generally regarded as safe, its immunotoxicological profile, when used as a polymeric nanoparticle (NP), is not well-documented. Thus, this study intends to address this gap, by evaluating the toxicity of two different sized PLA NPs (PLAA NPs and PLAB NPs), produced by two nanoprecipitation methods and extensively characterized regarding their physicochemical properties in in vitro experimental conditions. After production, PLAA NPs mean diameter (187.9 ± 36.9 nm) was superior to PLAB NPs (109.1 ± 10.4 nm). Interestingly, when in RPMI medium, both presented similar mean size (around 100 nm) and neutral zeta potential, possibly explaining the similarity between their cytotoxicity profile in PBMCs. On the other hand, in DMEM medium, PLAA NPs presented smaller mean diameter (75.3 ± 9.8 nm) when compared to PLAB NPs (161.9 ± 8.2 nm), which may explain its higher toxicity in RAW 264.7. Likewise, PLAA NPs induced a higher dose-dependent ROS production. Irrespective of size differences, none of the PLA NPs presented an inflammatory potential (NO production) or a hemolytic activity in human blood. The results herein presented suggest the hypothesis, to be tested in the future, that PLA NPs presenting a smaller sized population possess increased cytotoxicity. Furthermore, this study emphasizes the importance of interpreting results based on adequate physicochemical characterization of nanoformulations in biological medium. As observed, small differences in size triggered by the dispersion in cell culture medium can have repercussions on toxicity, and if not correctly evaluated can lead to misinterpretations, and subsequent ambiguous conclusions.
ABSTRACT
Azadirachta indica A. Juss, conhecida popularmente como "Neem" é uma árvore indiana, pertencente à família Meliaceae. Apresenta diferentes propriedades terapêuticas, dentre elas, a atividade antibacteriana, antiparasitária, antifúngica e moluliscida. O objetivo do trabalho foi avaliar a atividade antifúngica do extrato bruto das folhas de A. indica frente às cepa padrão de Candida albicans ATCC 10231. Os extratos de A. indica foram preparados utilizando o álcool etílico 70%, acetato de etila e hexano como agentes extratores. Para a determinação da CIM (Concentração Inibitória Mínima) dos extratos foram realizadas as técnicas de macrodiluição em tubos e microdiluição em placa empregando a técnica do MABA (Microplate Alamar Blue Assay). Para o extrato bruto produzido com álcool etílico 70% e hexano, revelaram-se incapazes de inibir a cepa C. albicans mesmo na concentração de 2000 µg/mL, o extrato a base de acetato de etila foi o único capaz de exercer efeitos inibitórios em C. albicans ATCC 10231 na concentração de 2000µg/mL.
Azadirachta indica A. Juss, popularly known as "Neem", is an Indian tree belonging to the Meliaceae family. It has several therapeutic properties, among them, the antifungal activity. The objective was to evaluate the antifungal activity of the crude extract from the leaves of A. indica in face of the standard Candida albicans ATCC 10231 strains. The extracts of A. indica were prepared using 70% ethanol, ethyl acetate and hexane as the extracting agent. For the determination of the MIC (Minimum Inhibitory Concentration) of the extracts, the techniques of macrodilution in tubes and microdilution on plates were performed, using the MABA (Microplate Alamar Blue Assay) technique. The crude extract produced with 70% ethanol and hexane proved to be unable to inhibit C. albicans strain even at a concentration of 2000µg/mL, whereas the ethyl acetate extract was the only one able to exert inhibitory effects on C. albicans ATCC 10231 at a concentration of 2000µg/mL.
Subject(s)
Antifungal Agents , Azadirachta , Candida albicans , MicrobiologyABSTRACT
Azadirachta indica A. Juss, conhecida popularmente como ?Neem? é uma árvore indiana, pertencente à família Meliaceae. Apresenta diferentes propriedades terapêuticas, dentre elas, a atividade antibacteriana.O objetivo do trabalho foi avaliar a atividade antibacteriana do extrato bruto das folhas de A. indica frente às cepa padrão de Streptococcus pyogenes ATCC 19615. Os extratos de A. indica foram preparados utilizando o álcool etílico 70%, acetato de etila e hexano como agentes extratores. Para a determinação da Concentração Inibitória Mínima (CIM) dos extratos foram realizadas as técnicas de macrodiluição em tubos e microdiluição em placa empregando a técnica do Microplate Alamar Blue Assay (MABA). Para o extrato bruto produzido com álcool etílico 70%, revelou-se capaz de inibir a cepa S.pyogenes na concentração de 4000µg/mL; para o hexano e acetato de etila foi possível denotar efeitos inibitórios em 2000 µg/mL e 250 µg/mL respectivamente. Destaca-se o extrato bruto produzido com acetato de etila, por apresentar melhor atividade antibacteriana, dentre os testes.
Azadirachta indica A. Juss, popularly known as ?Neem?, is an Indian tree belonging to the Meliaceae family. It has several therapeutic properties, among which, the antibacterial activity. The aim of this paper was to evaluate the antibacterial activity of the crude extract from the leaves of A. indica in relation to the standard strain of Streptococcus pyogenes ATCC 19615. The extracts of A. indica were prepared using ethanol 70%, ethyl acetate and hexane as the extracting agent. In order to determine the MIC (Minimum Inhibitory Concentration) of the extracts, the macro dilution in tubes and micro dilution on plates using the MABA (Microplate Alamar Blue Assay) technique were used. The results presented reveal that among the techniques used for the study, ethanol 70% was able to inhibit the S. pyogenes strain at concentration of 4000?g/mL; and that hexane and ethyl acetate presented possible inhibitory effects at 2000µg/mL and 250 µg/mL, respectively. It is important to emphasize that the crude extract produced with ethyl acetate presented the best antibacterial activity among the tests.
