Biogenic gold nano-triangles: cargos for anticancer drug delivery.

We present synthesis of biogenic gold nano triangles (GNTs) using Azadirachta indica leaf extract at inherent pH (5.89) and its application in efficient drug delivery of doxorubicin (DOX) (anticancer drug). The main idea was to take advantage of large surface area of GNTs which has 3 dimensions and use the plant peptides coated on these triangles as natural linkers for the attachment of DOX. Sucrose density gradient centrifugation (SDGC) and dialysis methods were used for separation of the GNT from mixture of GNPs. Flocculation parameter (FP) was used to check stability of GNT which was found to be exceptionally high (0-0.75) due to the biological capping agents. DOX attachment to GNT was verified using Fourier transformed infra-red (FTIR) spectroscopy. The complex thus formed was found to be less toxic to normal cells (MDCK cells) and significantly toxic for the cancerous cells (HeLa cells). Drug loading efficiency was found to be 99.81% and DOX release followed first order release kinetics. Percentage drug release was found to be more than 4.5% in both acidic (5.8) as well as physiological pH (7.2) which is suitable for tumor targeting.

Biogenic gold nanoparticles as fotillas to fire berberine hydrochloride using folic acid as molecular road map.

Use of biologically modified gold nanoparticles (GNPs) as molecular vehicle to ferry potential anti-cancer drug berberine hydrochloride (BHC) using folic acid (FA) as targeting molecule is reported in this work. A tropical fruit peel, Trapa bispinosa is used to fabricate highly monodispersed GNPs, passivated with essential functional groups which were used as linkers to attach FA and BHC via amide linkage. Flocculation Parameter (FP) of biologically synthesized GNPs was calculated under different salt concentrations which were found to be very ideal under a physiological condition. Various statistical models were used to find drug release profile out of which Higuchi was found to be the most ideal. GNP-FA-BHC complexes were found to be active against folic acid expressing HeLa cells.

A comparative study of economical separation and aggregation properties of biologically capped and thiol functionalized gold nanoparticles: selecting the eco-friendly trojan horses for biological applications.

We are presenting facile bio-fabrication of extremely stable gold nanoparticles (GNPs) using medicinal plant Azadirachta indica (commonly called Neem) and its comparison with most commonly used glutathione (GSH) protected GNPs in terms of stability under physiological conditions, seperation using density gradient centrifugation and aggregation properties in the solution. There was dual peak at 536 and 662 nm indicating the presence of non-spherical GNPs including triangles, rods and hexagons in case of A. indica mediated GNPs unlike citrate stabilized GNPs which exhibited single sharp peak. Spherical GNPs were separated from the consortium of uniquely shaped nanoparticles bio-fabricated using A. indica leaf extract using sucrose density gradient centrifugation (SDGC).To comprehend the anti-agglomeration potentials of A. indica leaf mediated GNPs and GSH-GNPs under physiological conditions, flocculation parameters (FP) were calculated and found to be least for A. indica leaf mediated GNPs, indicating their exceptional stability.

Green synthesis of biocompatible carbon dots using aqueous extract of Trapa bispinosa peel.

We are reporting highly economical plant based method for the production of luminescent water soluble carbon dots (C-dot) using Indian water plant Trapa bispinosa peel extract without adding any external oxidizing agent at 90 °C. C-dots ranging from 5 to 10nm were found in the solution with a prominent green fluorescence under UV-light (λex=365 nm). UV-vis spectra recorded at different time intervals (30-120 min) displayed signature absorption of C-dots between 400 and 600 nm. Fluorescence spectra of the dispersion after 120 min of synthesis exhibited characteristic emission peaks of C-dots when excited at 350, 400, 450 and 500 nm. C-dots were further analyzed using X-ray diffraction (XRD), Raman Spectroscopy and Thermo-Gravimetric Analysis (TGA). Structure of the C-dots was found to be turbostratic when studied using XRD. C-dots synthesized by our method were found to be exceptionally biocompatible against MDCK cells.

Antimicrobial activity of crude extracts from plant parts and corresponding calli of Bixa orellana L.

Ethanol extracts from the different parts of B. orellana showed differential antimicrobial activity. It was found that the extracts of in vitro leaves showed maximum activity against Bacillus pumilus followed by the extracts from the roots and hypocotyls. The callus derived from different explants too showed antimicrobial activity. The leaf callus showed maximum activity. The zone of inhibition for the diluted extracts of in vitro hypocotyls and roots and their corresponding calli showed minimum zone of inhibition at concentration 24 mg/ml, whereas the diluted extract of in vitro leaves and leaf derived callus showed minimum zone of inhibition at 16 mg/ml.