pH-induced fluorescent active sodium alginate-based ionically conjugated and REDOX responsive multi-functional microgels for the anticancer drug delivery.

A sodium alginate (Alg) based REDOX (reduction and oxidation)-responsive and fluorescent active microgel was prepared via water in oil (w/o) mini-emulsion polymerization technique. Here, we initially synthesized sodium alginate-based disulfide cross linked microgels and after that those microgels were tagged with rhodamine amine derivative (RhB-NH2) by ionic interaction to get the pH-responsive fluorescent property. Functionalized microgels were characterized using 1H NMR, FTIR, DLS, HRTEM, FESEM, UV-vis, and fluorescence spectroscopy analyses. Presence of the REDOX-responsive disulfide-containing crosslinkers in the microgels enhances the release of doxorubicin (DOX), an anti-cancer drug in the reducing environment of the cancer-cells (simulated). Existence of the rhodamine-amine derivative in the microgels triggers the pH-dependent fluorescence property by showing fluorescence emission at 560-580 nm at pH 5.5 (cancer cell pH). The cytotoxicity of the biopolymer based microgel was assessed over both cancerous HeLa (IC50 100 µg/mL) and non-cancerous MDCK (IC50 200 µg/mL) cells by MTT assay which showed the synthesized microgel is non-toxic whereas DOX-loaded microgels showed significant toxicity. FACS and cell uptake (in vitro) analyses were conducted to understand the cell apoptosis cycle and behavior of the cancer cells in presence of the DOX-loaded microgels. This pH-responsive fluorescent active alginate-based biomaterial could be a promising material for the anti-cancer drug delivery and other medical fields.

Current synthesis and characterization techniques for clay-based polymer nano-composites and its biomedical applications: A review.

Clays and its composites have received considerable attention recently due to their low cost, wide availability and low environmental impact. The development of various preparation processes and applications of innovative polymer-nanoclay composites has been aided by recent breakthroughs in material technologies. Novel polymer-nanoclay composites with better qualities have been effectively adopted in a variety of fields, including aerospace, car, construction, petroleum, biomedical, and wastewater treatment, owing to innovative production processes. Due to their superior qualities, such as increased density, strength, relatively large surface areas, high elastic modulus, flame retardancy, and thermomechanical/optoelectronic/magnetic capabilities, these composites are acknowledged as potential advanced materials. Hence the present paper reviews the advances in synthesis and preparation of clay-polymer nanocomposites. In addition, this study also focuses on the various techniques used for clay-polymer nanocomposites characterization e.g. scanning electron microscope (SEM), transmission electron microscope (TEM), thermo-gravimetric analysis (TGA) and differential colorimetric analysis (DSC), x-ray diffraction (XRD) analysis, Nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopic (FTIR) characterization. These advanced physico-mechanical and chemical characterization techniques would be effective in understanding the most appropriate application of clay polymer nanocomposites. In addition, the application of clay polymer nanocomposites in biomedical sector is also discussed in brief.