The Synthesis of Gold Nanoparticles Using <i>Amaranthus spinosus</i>Leaf Extract and Study of Their Optical Properties

We report here the application of a medicinally important plant Amaranthus spinosus for the synthesis of gold nanoparticles (AuNPs). Different concentrations of ethanolic leaf extract of the plant were reacted with aqueous solution of HAuCl4·4H2O under mild reaction conditions. Synthesis of AuNPs was confirmed from the UV-Vis study of surface plasmon resonance property of the colloidal solution. Transmission electron microscopy (TEM) revealed particles as spherical and triangular in shape. X-ray diffraction (XRD) confirmed the crystalline nature of AuNPs with average size of 10.74 nm as determined by Debye-Scherrer’s Equation. Fourier transform infra-red (FT-IR) analysis of leaf extract and lyophilized AuNPs showed the presence of various functional groups present in diverse phytochemicals. Energy dispersive X-ray (EDX) of purified AuNPs confirmed the formation of AuNPs and surface adsorption of biomolecules. We further investigated the toxicity of the synthesized AuNPs and found non toxic to the cancer cell lines and could be used for biomedical applications.

Applications of silk-based biomaterials in biomedicine and biotechnology

Silk-based biomaterials have gained significant importance making them a promising choice for the future of med-ical technology due to their versatility and biocompatibility.They can be fabricated and tailored through various processing methods such as electrospinning,freeze-drying,and 3D printing,to achieve specific properties and structures namely sponges,hydrogels,films,and scaffolds that can be utilized for different biomedical applica-tions.Biocompatibility,a unique property of silk-based biomaterials,has been demonstrated through both in vivo and in vitro studies and to date many studies have reported the successful use of these silk-based biomaterials in different fields of medicine.In this review,we have elaborately discussed different types of silk,their structural composition,and biophysical properties.Also,the current review focuses on highlighting various biomedical ap-plications of engineered and fabricated silk-based biomaterials which aid in the treatment of certain infections and diseases related to skin,eyes,teeth,bone,heart,nerves,and liver.Furthermore,we have consolidated the advancements of silk-based biomaterials in the different fields of biotechnology such as sensors,food coating and packaging,textiles,drug delivery,and cosmetics.However,the research in this field continues to expand and more significant observations must be generated with feasible results for their reliable use in different biomedical applications.

Green synthesis of biocompatible gold nanoparticles using Fagopyrum esculentum leaf extract

This report describes the use of ethnolic extract of Fagopyrum esculentum leaves for the synthesis of gold nanoparticles. UV-visible spectroscopy analysis indicated the successful formation of gold nanoparticles. The synthesized nanoparticles were characterized by transmission electron microscopy （TEM）, high resolution TEM （HRTEM） and were found to be spherical, hexagonal and triangular in shape with an average size of 8.3 nm. The crystalline nature of the gold nanoparticles was confirmed from X.ray diffraction （XRD） and selected-area electron diffraction （SAED） patterns. Fourier transform infrared （FT-IR） and energy.dispersive X-ray analysis （EDX） suggested the presence of organic biomolecules on the surface of the gold nanoparticles. Cytotoxicity tests against human HeLa, MCF-7 and IMR-32 cancer cell lines revealed that the gold nanoparticles were non-toxic and thus have potential for use in various biomedical applications.