Biocompatibility evaluation of pH and glutathione-responsive nanohydrogels after intravenous administration.

Nanotoxicology has emerged as an important subdiscipline of nanotechnology due to the new healthy risks associated with the use of nanosystems for therapy and diagnostic. The biocompatibility of four stimuli-responsive nanohydrogel (NG) formulations based on different proportions of N-isopropylacrylamide (NIPA), N-hydroxyethyl acrylamide (HEAA) and 2-acrylamidoethyl carbamate (2AAECM), and cross-linked with N,N-cystaminebisacrylamide (CBA) or N-methylenebisacrylamide (NMBA) has been evaluated after intravenous injection in Wistar rats. All nanohydrogels were pH-sensitive, and those with CBA were also glutathione-responsive.

In-vivo evaluation of tamoxifen-loaded microspheres based on mixtures of poly (D,L-lactide-co-glycolide) and poly (D,L-lactide) polymers.

Microspheres of different proportions of poly-(D,L-lactide-co-glycolide) and poly-(D,L-lactide) were formulated by spray drying as a drug-delivery system for the treatment of breast cancer with tamoxifen. These systems had been evaluated previously in vitro and showed very positive results that have led to further assessment in vivo. This work evaluates the performance of these systems in an organism by carrying out a study in female Wistar rats.

Modulation of lysozyme activity by lead administered by different routes. In vitro study and analysis in blood, kidney, and lung.

Modifications in the enzyme activity of lysozyme, a protein implied in the defence barrier of the organism, can be a good biomarker of alterations in the immune system as a result of exposure to toxic metal, such as lead. The aim of this work was to evaluate the effect of a 200 ppm dose of lead on lysozyme activity in blood, kidney, and lung, and also on tissue structure. Previously, the effect of lead acetate on lysozyme activity in vitro was determined; the in vitro results indicated that lead produced a decrease in enzyme activity.

Tamoxifen-loaded folate-conjugate poly[(p-nitrophenyl acrylate)-co-(N-isopropylacrylamide)] sub-microgel as antitumoral drug delivery system.

Folate-conjugate poly[(p-nitrophenyl acrylate)-co-(N-isopropylacrylamide)] sub-microgel (F-SubMG) was loaded with tamoxifen (TMX) to obtain low (9.0 ± 0.4 μg TMX/mg F-SubMG) and high (112.

Mast cell inhibition by ketotifen reduces splanchnic inflammatory response in a portal hypertension model in rats.

Experimental early prehepatic portal hypertension induces an inflammatory exudative response, including an increased infiltration of the intestinal mucosa and the mesenteric lymph nodes by mast cells and a dilation and tortuosity of the branches of the superior mesenteric vein. The aim of this study is to verify that the prophylactic administration of Ketotifen, a stabilizing drug for mast cells, reduces the consequence of splanchnic inflammatory response in prehepatic portal hypertension. Male Wistar rats were used: Sham-operated and with Triple Partial Portal Vein Ligation, which were subcutaneously administered poly(lactide-co-glycolide) acid microspheres with vehicle 24h before the intervention and SO and rats with Triple Partial Portal Vein Ligation, which were administered Ketotifen-loaded microspheres.

Ketotifen-loaded microspheres prepared by spray-drying poly(D,L-lactide) and poly(D,L-lactide-co-glycolide) polymers: characterization and in vivo evaluation.

Ketotifen (KT) was encapsulated into poly(D,L-lactide) (PLA) and poly(D,L-lactide-co-glycolide) (PLGA 50/50) by spray-drying to investigate the use of biodegradable drug-loaded microspheres as delivery systems in the intraperitoneal cavity. Ketotifen stability was evaluated by HPLC, and degradation was not observed. Drug entrapment efficiency was 74 +/- 7% (82 +/- 8 microg KT/mg for PLA) and 81 +/- 6% (90 +/- 7 microg KT/mg for PLGA 50/50).

5-Fluorouracil plasma levels and biodegradation of subcutaneously injected drug-loaded microspheres prepared by spray-drying poly(D,L-lactide) and poly(D,L-lactide-co-glycolide) polymers.

Microspheres (MS) of 5-fluorouracil-loaded poly(D,L-lactide) (PLA), poly(D,L-lactide-co-glycolide) 75/25 (PLGA 75/25) and poly(D,L-lactide-co-glycolide) 50/50 (PLGA 50/50) prepared by the spray-drying technique were subcutaneously injected in the back of Wistar rats in order to evaluate the 5-fluorouracil (5-FU) release and the biodegradation characteristics. Determination of plasma 5-FU concentration by HPLC with analysis of data using a non-compartmental model showed drug in plasma between 9 and 14 days after administration of drug-loaded PLGA 50/50 or PLA and PLGA 75/25 microspheres, respectively, with a maximum drug concentration of 2.4+/-0.