Self-assembled micelles of the (lipo) glycopeptides, teicoplanin, as taxane nanocarriers.

The use of nanoparticles is one of the strategies currently studied to minimize the toxicity and lack of tissue specificity of many cancer drugs used in chemotherapy. In this research the physicochemical and biological behavior of a novel self-assembled nanostructure of the antibiotic Teicoplanin (Teico) was characterized as a nanocarrier system for solubilizing highly hydrophobic drugs like Paclitaxel (Ptx) in aqueous media. The Teico micelles were loaded with Ptx in DMSO or PEG-400. The interaction between the loaded micelles and Albumin human serum albumin (HSA) was then studied by size exclusion chromatography. Transmission electron microscopy, dynamic light scattering and high-resolution liquid chromatography were also used to characterize the physicochemical and structural properties of the micelles to form the Teico/Ptx and Teico/Ptx/HSA micelles. Cellular uptake of Ptx was evaluated by fluorescent microscopy. Thein vitrocytotoxicity of the complexes was studied on Hep-2 tumor cells, by a Crystal Violet assay. Teico cosolvent-free micelles can solubilize up to 20 mg.ml-1of Ptx dissolved in PEG, increasing four times the solubility of Ptx in water compared to Abraxane, and 20 000 times the intrinsic solubility of Ptx in water. In addition, Teico/Ptx micelles binds spontaneously HSA through hydrophobic interaction. Teico and Teico/HSA micelles as a Ptx transporter does not affect its release or biological activity. Therefore, Teico/Ptx or Teico/Ptx/HSA complexes appear as new alternatives for transporting larger amounts of hydrophobic drugs that offer advantages, turning it an interesting option for further study.

Testosterone-loaded GM1 micelles targeted to the intracellular androgen receptor for the specific induction of genomic androgen signaling.

Androgens play a central role in homeostatic and pathological processes of the prostate gland. At the cellular level, testosterone activates both the genomic signaling pathway, through the intracellular androgen receptor (AR), and membrane-initiated androgen signaling (MIAS), by plasma membrane receptors. We have previously shown that the activation of MIAS induces uncontrolled proliferation and fails to stimulate the beneficial immunomodulatory effects of testosterone in prostatic cells, becoming necessary to investigate if genomic signaling mediates homeostatic effects of testosterone. However, the lack of specific modulators for genomic androgen signaling has delayed the understanding of this mechanism. In this article, we demonstrate that monosialoganglioside (GM1) micelles are capable of delivering testosterone into the cytoplasm to specifically activate genomic signaling. Stimulation with testosterone-loaded GM1 micelles led to the activation of androgen response element (ARE)-regulated genes in vitro as well as to the recovery of normal prostate size and histology after castration in mice. In addition, these micelles avoided MIAS, as demonstrated by the absence of rapid signaling pathway activation and the inability to induce uncontrolled cell proliferation. In conclusion, our results validate a novel tool for the specific activation of genomic androgen signaling and demonstrate the importance of selective pathway activation in androgen-mediated proliferation.

Ocular biocompatibility of polyquaternium 10 gel: functional and morphological results.

This paper deals with the characterization study of topical and intraocular biocompatibility and toxicity of cationic hydroxyethylcellulose Polyquaternium 10 (PQ10). It also evaluates the rheological properties of gels. The cytotoxicity assays were done in two cell lines: HEp-2 and VERO (human larynx epidermoid carcinoma cell and African green monkey kidney cells respectively). For the in vivo study, New Zealand albino rabbits were used. The in vitro cytotoxic activity of PQ10 shows no statistically significant differences in relation to the control of hydroxypropylmethylcellulose (HPMC) in any of the cell lines used in this study. Similarly, the signs of inflammation observed after treatment showed no significant difference between the groups of animals treated with the polymer compared to the control group. Normal histological characteristics were seen in both groups with no histological inflammatory reaction. After 1 month of the intracameral application of 2% PQ10 (treatment group) or 0.3% HPMC (control group), electroretinograms showed similar levels of a- and b-waves latencies and amplitude. In summary, PQ10 gel was well tolerated in these experiments, with proper monitoring, it could stand as a new alternative in the development of ophthalmic viscosurgical devices.

Efectividad de la metformina en pacientes con diabetes tipo II según variantes en el gen SLC22A1 / Effectiveness of Metformin in patients with type II diabetes related to variants in the SLC22A1 gene / Eficácia de Metformina em doentes com diabetes tipo II, relacionado com variantes do gene SLC22A1

La diabetes mellitus tipo II (DM II) es una enfermedad que afecta una gran cantidad de individuos. Un medicamento empleado en el tratamiento de los pacientes es la metformina. Este medicamento es transportado al interior de los hepatocitos por un transportador codificado por el gen SLC22A1. Variantes en el gen con actividad reducida pueden disminuir la cantidad de metformina disponible en el hígado y reducir la respuesta terapéutica. Se propuso evaluar diferentes parámetros bioquímicos en relación a la dosis de metformina y la presencia de variantes en el transportador. Se estudiaron 103 pacientes mayores de 18 años con diagnóstico de DM II, tratados con 1700 mg/día de metformina por más de 6 meses. Se analizaron 5 polimorfismos en el gen SLC22A1, glucemia, HbA1c, función hepática, perfil lipídico y renal. Los niveles de HbA1c y de glucemia fueron más elevados en los pacientes que presentaban los polimorfismos R61C, G401S, M420del y G465R aunque la diferencia fue estadísticamente significativa sólo para la HbA1c en los pacientes que presentaban las variantes M420del y G465R (p=0,0273 y 0,0018, respectivamente). La presencia de polimorfismos con actividad reducida en el gen SLC22A1 afecta los niveles de glucemia y de HbA1c en pacientes con DM II cuando son tratados con metformina.

Diabetes mellitus type II (DM II) is a disease that affects a large number of individuals. One of the drugs used for the treatment is metformin. Metformin is delivered into hepatocytes by a transporter encoded by the SLC22A1 gene. Gene variants with reduced activity may decrease the amount of metformin available in the liver and reduce the therapeutic response. Various biochemical parameters were evaluated in relation to the metformin dose and the presence of transporter variants. A total of 103 patients older than 18 diagnosed with DM II who were treated with 1700 mg/day of metformin for more than six months were studied. Five polymorphisms in the SLC22A1 gene were analyzed as well as glycemia, HbA1c level, liver function, and lipid and kidney profiles. HbA1c and glycemia levels were higher in patients with the R61C, G401S, M420del and G465R polymorphisms; although the difference was statistically significant only for HbA1c in patients with the M420del and G465R variants (p=0.0273 and 0.0018, respectively). Polymorphisms with reduced activity in the SLC22A1 gene affect blood glucose levels and HbA1c in patients with DM II when they are treated with metformin.

O diabetes mellitus tipo II (DM II) é uma doença que afeta uma grande quantidade de indivíduos. Um medicamento utilizado no tratamento dos doentes é a metformina. Esse medicamento é transportado no interior dos hepatócitos por um transportador codificado pelo gene SLC22A1. Variantes no gene com atividade reduzida podem diminuir a quantidade de Metformina disponível no fígado e reduzir a resposta terapêutica. Propôs-se avaliar diferentes parâmetros bioquímicos em relação à dose da metformina e à presença de variantes no transportador. Foram estudados 103 pacientes maiores de 18 anos com diagnóstico de DM II tratados com 1700 mg/dia de metformina por mais de 6 meses. Foram analisados 5 polimorfismos no gene SLC22A1; glicemia, HbA1c, função hepática, perfil lipídico e renal. Os níveis de HbA1c e de glicemia foram superiores em doentes que apresentavam os polimorfismos R61C, G401S, M420del e G465R; embora a diferença seja estatisticamente significativa apenas para o HbA1c nos doentes que apresentavam as variantes M420del e G465R (p=0,0273 e 0,0018; respectivamente). A presença de polimorfismos com atividade reduzida no gene SLC22A1 afeta os níveis da glicemia e do HbA1c em doentes com DM II quando são tratados com metformina.