Abstract:In this article, Sodium alginate and Lignosulphonic acid blends were prepared in different weight ratios by solution casting method. Swelling experiments were conducted for Sodium alginate and its blends by adding calcium chloride for various intervals in a pH 7.4 medium. The strength of the films increases after their treatment with CaCl 2 at higher intervals forming an alginate network. The SA/LS blend (80/20) is subjected for sorption studies at variable pH 1.2 & 7.4, in order to test the suitability of the blends for controlled drug delivery. Further, experiments were conducted for de-crosslinking using 0.1M HCl. The solvent uptake for the blends decreased with increasing LS content in the blends. Blends were investigated by X-ray diffraction and Fourier Transform Infra-Red spectroscopy in order to study the crystallinity and molecular interactions. XRD confirms the reduction in cluster space in blends leading to lower uptake of solvent.

Alginates are natural polysaccharides available as seaweed products. They possess several properties due to their molecular structure made of bipolymeric α-L-Guluronic acid and β-D-Mannuronic acid polymers. Alginates have several properties such as film-forming ability, pH responsiveness, and gelling, hydrophilicity, biocompatibility, biodegradability, non-toxic, processability and ionic crosslinking. They’re commonly used in several industries, including food, pharmaceuticals, dental applications, welding rods and scaffolding. Due to their gelling and non-toxic properties, as well as their abundance in nature, the cosmetics and healthcare industries have shown a great deal of interest in biodegradable polymers in general and alginates particularly over the last few decades.

Blends of sodium alginate (SA) and lignosulphonic acid (LS) has been prepared in the ratio of 80/20. The prepared blends were crosslinked using chlorides of calcium, barium, strontium and aluminum. The crosslinking of blends was done for different time intervals and then these blends were subjected for swelling studies in aqueous medium of pH 7.4. The observations indicate that the crosslinking is diffusion controlled and is affected by the size of metal ion and the type of alginate used. The improved swelling time for crosslinked blends in aqueous medium supports the fact that the stability under physiological conditions of the blends is improved due to crosslinking with the metal ions. Calcium chloride and barium chloride forms strong crosslink with the blend. Calcium ion crosslinked blends can be considered suitable for biomedical drug applications. The investigations on crosslinked blends using FTIR, SEM, XRD and EDAX are in close agreement with swelling results.

The synthesis of silver nanoparticles is of great importance because of the fact that their application is sensitive to the shape, size and its distribution. Bio medical application also demands that nanoparticles should be free from contaminants. Quest for synthetic methods which are benign to both human and environment led researchers to use locally available biogenic products for silver nanoparticle synthesis. Present review article, is based on the available literature on the use of microorganisms and plants for silver nanoparticle synthesis. Also the factors affecting the synthesis, role of phyto chemicals and proposed application of synthesized nanoparticles have been reported.

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