Optimization of Biogenic Synthesis of Colloidal Metal Nanoparticles

Nanotechnology which deals with the synthesis and characterization of dispersed or solid particles in nano-metric range has emerged out to be a novel approach due to its ample applications in biomedical fields. The advancements in the field of nanotechnology and substantial evidences in biomedical applications have led the researchers to explore safe, ecofriendly, rapid and sustainable approaches for the synthesis of colloidal metal nanoparticles. This chapter illustrates superiority of biogenic route of synthesis of nanoparticles over the different approaches such as chemical and physical methods. In biogenic route, plants and microorganisms like algae, fungi, yeast, actinomycetes etc. act as “bio-factories” which reduce the metal precursors and play a crucial role in the synthesis of nanoparticles with distinct morphologies. Thus, the need of hazardous chemicals is eliminated and a safer and greener approach of nanoparticles synthesis can be adopted. This chapter also outlines the effect of optimization of different parameters mainly pH, temperature, time and concentration of metal ions on the nanoparticle synthesis. It is evident that the optimization of various parameters can yield nanoparticles with desired properties suitable for respective biomedical applications

Optimally biosynthesized, PEGylated gold nanoparticles functionalized with quercetin and camptothecin enhance potential anti-inflammatory, anti-cancer and anti-angiogenic activities

The development of nano delivery systems is rapidly emerging area of nanotechnology applications where nanomaterials (NMs) are employed to deliver therapeutic agents to specific site in a controlled manner. To accomplish this, green synthesis of NMs is widely explored as an eco-friendly method for the development of smart drug delivery system. In the recent times, use of green synthesized NMs, especially metallic NMs have fascinated the scientific community as they are excellent carriers for drugs. This work demonstrates optimized green, biogenic synthesis of gold nanoparticles (AuNPs) for functionalization with quercetin (QT) and camptothecin (CPT) to enhance potential anti-inflammatory, anti-cancer and anti-angiogenic activities of these drugs. Results: Gold nanoparticles were optimally synthesized in 8 min of reaction at 90 °C, pH 6, using 4 mM of HAuCl4 and 4:1 ratio of extract: HAuCl4. Among different capping agents tested, capping of AuNPs with polyethylene glycol 9000 (PG9) was found best suited prior to functionalization. PG9 capped AuNPs were optimally functionalized with QT in 1 h reaction at 70 °C, pH 7, using 1200 ppm of QT and 1:4 ratio of AuNPs-PG9:QT whereas, CPT was best functionalized at RT in 1 h, pH 12, AuNPs-PG9:CPT ratio of 1:1, and 0.5 mM of CPT. QT functionalized AuNPs showed good anti-cancer activity ( IC50 687.44 μg/mL) against MCF-7 cell line whereas test of anti-inflammatory activity also showed excellent activity ( IC50 287.177 mg/L). The CAM based assessment of anti-angiogenic activity of CPT functionalized AuNPs demonstrated the inhibition of blood vessel branching confirming the anti-angiogenic effect. Conclusions: Thus, present study demonstrates that optimally synthesized biogenic AuNPs are best suited for the functionalization with drugs such as QT and CPT. The functionalization of these drugs with biogenic AuNPs enhances the potential anti-inflammatory, anti-cancer and anti-angiogenic activities of these drugs, therefore can be used in biomedical application