Temperature-Responsive Polymer Microgel-Gold Nanorods Composite Particles: Physicochemical Characterization and Cytocompatibility

In this paper, we report an easy route for preparing new metal nanorod-polymer composites consisting of gold nanorods, Au NRs, and temperature responsive copolymer “microgel” particles. The microgel particles of ~200 nm in size, which contain carboxylic acid groups, were prepared by surfactant-free emulsion polymerization of a selected mixture made of N-isopropylacylamide and acrylic acid in the presence of a cross-linker N,N′-methylenebisacrylamide. The electrostatic interactions between the cationic cetyltrimethylammonium bromide (CTAB) stabilized Au NRs and anionic microgel particles were expected to occur in order to prepare stable Au NRs-microgel composite particles. The optical and structural characterization of the composite was achieved using UV-Vis spectroscopy, Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM) and dynamic light scattering (DLS). TEM image shows that Au NRs are attached on the surface of the microgel particles. Dynamic light scattering measurements prove that the composite particles are temperature responsive, which means the particles undergo a decrease in size as the temperature increases above its phase transition temperature. In vitro cytotoxicity of the composite materials were tested by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Lactate dehydrogenase (LDH), and hemolysis assay, which showed non-toxicity (biocompatibility)

Antioxidant potential of Rumex vesicarius L.: in vitro approach

Objective: To assess in-vitro antioxidant activity of different fraction and perform high performance thin layer chromatography fingerprint analysis of most active fraction of Rumex vesicarius L. (R. vesicarius). Methods: In the present study, acetone, ethyl acetate, n-butanol, and methanol extracts of R. vesicarius were evaluated for radical scavenging activity by studying the inhibition of the level of lipid peroxidation induced by Fe(++)/ascorbate, DNA sugar damage, scavenging of hydrogen peroxide, diphenylphosphine DPPH radical scavenging activity, total phenolic content, total flavonoids content and total proanthocyanidin. High performance thin layer chromatography finger print profiling of R. vesicarius L. was also done. Results: Lipid peroxidation induced by the iron/ascorbate system, hydrogen peroxide, diphenylphosphine and DNA sugar damage were inhibited by the addition of different extract of R. vesicarius. Among them, methanolic extract showed maximum efficacy. The methanolic extract showed the highest total phenolic, total flavonoids and total proanthocyanidin contents. Conclusions: The results suggest that the extracts can be a vital source of phytochemical antioxidants