RESUMO
The aim of the present work was to encapsulate 18-ß-Glycyrrhetinic acid (GLA) in albumin conjugated poly(lactide-co-glycolide) (PLGA) nanoparticles by a modified nanoprecipitation method. Nanoparticles (NPs) were prepared by different drug to polymer ratios, human serum albumin (HSA) content, dithiothreitol (as producer of free thiol groups) content, and acetone (as non-solvent in nanoprecipitation). NPs with a size ranging from 126 to 174 nm were achieved. The highest entrapment efficiency (89.4±4.2%) was achieved when the ratio of drug to polymer was 1:4. The zeta potential of NPs was fairly negative (-8 to -12). Fourier transform infrared spectroscopy and differential scanning calorimetry proved the conjugation of HSA to PLGA NPs. In vitro release profile of NPs showed 2 phases: an initial burst for 4 h (34-49%) followed by a slow release pattern up to the end. The antibacterial effects of NPs against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa were studied by microdilution method. The GLA-loaded NPs showed more antibacterial effect than pure GLA (2-4 times). The anticancer MTT test revealed that GLA-loaded NPs were approximately 9 times more effective than pure GLA in Hep G2 cells.
Assuntos
Albuminas/química , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Portadores de Fármacos/química , Ácido Glicirretínico/farmacologia , Ácido Láctico/química , Nanopartículas/química , Ácido Poliglicólico/química , Antibacterianos/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Liberação Controlada de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Ácido Glicirretínico/administração & dosagem , Ácido Glicirretínico/química , Células Hep G2 , Humanos , Testes de Sensibilidade Microbiana , Copolímero de Ácido Poliláctico e Ácido PoliglicólicoRESUMO
The effectiveness of anticancer agents may be hindered by low solubility in water, poor permeability, and high efflux from cells. Nanomaterials have been used to enable drug delivery with lower toxicity to healthy cells and enhanced drug delivery to tumor cells. Different nanoparticles have been developed using different polymers with or without surface modification to target tumor cells both passively and/or actively. Polylactide-co-glycolide (PLGA), a biodegradable polyester approved for human use, has been used extensively. Here we report on recent developments concerning PLGA nanoparticles prepared for cancer treatment. We review the methods used for the preparation and characterization of PLGA nanoparticles and their applications in the delivery of a number of active agents. Increasing experience in the field of preparation, characterization, and in vivo application of PLGA nanoparticles has provided the necessary momentum for promising future use of these agents in cancer treatment, with higher efficacy and fewer side effects.
Assuntos
Antineoplásicos/administração & dosagem , Sistemas de Liberação de Medicamentos , Ácido Láctico/administração & dosagem , Ácido Poliglicólico/administração & dosagem , Antineoplásicos/química , Preparações de Ação Retardada , Ácido Láctico/química , Nanotecnologia , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido PoliglicólicoRESUMO
Various electrokinetic phenomena in microfluidics have been utilised to manipulate microfluids and particles for lab-on-a-chip applications. Microfluidic channels with traditional planar floor configuration designs have limited pumping efficiency due to the fast backward flow over the electrode surface. This study reports optimal design of a microchannel with a microgrooved configuration for conductive fluid transport with alternating current electrothermal actuations. Significant improvements in flowrate are achieved over the planar configurations without additional temperature rises. The frequency and temperature dependences of AC electrothermal (ET) flow are investigated and analysed.
