The present study focused on the development of a novel biodegradable nanoparticle system based on polyethyleneglycol-modified gelatin (PEG-GEL) and polylactic acid (PLA) biopolymers for improving the photodynamic efficacy of cyclohexane-1,2-diamino hypocrellin B (CHA2HB), a potent photodynamic therapeutic (PDT) agent. The CHA2HB-loaded PEG-GEL/PLA nanoparticles showed near-spherical morphology with an average size of 190 nm at a PLA to PEG-GEL ratio of 1:3. The drug loading was sufficient enough to produce potentially toxic reactive oxygen species (ROS) needed for photodynamic therapy (PDT). Slow and controlled drug release was observed in normal conditions, whereas enzyme assistance resulted in a relatively fast release due to partial disintegration of CHA2HB-loaded PEG-GEL/PLA nanoparticles. In vitro experiments indicated that CHA2HB-loaded PEG-GEL-PLA nanoparticles are efficiently taken up by cancer cells such as human breast adenocarcinoma (MCF-7), human gastric sarcoma (AGS) and mice specific Dalton's lymphoma (DLA) in a time dependent manner. Further, CHA2HB-loaded PEG-GEL/PLA nanoparticles evoked superior phototoxicity compared to free-CHA2HB towards all the three cell lines investigated. Interestingly, PDT effectiveness was different for the different cell type studied. CHA2HB-loaded PEG-GEL/PLA nanoparticles induced both apoptotic and necrotic cell death as a result of photoirradiation. Thus, our data suggest that PEG-GEL/PLA nanoparticles are highly effective in delivery and phototoxic enhancement of CHA2HB against model cancer cells in vitro.

A simple method for the rapid synthesis of selenium nanoparticles (SeNPs) by the reduction of selenium dioxide using an aqueous egg white lysozyme solution (stabilizing agent) and ascorbic acid solution (reducing agent) has been described. The formation of SeNPs is assured by characterization with UV-Vis, FT-IR, XRD and morphological characters that were observed using TEM analyses. The absorbance of the SeNPs is found at 250 nm. The TEM images show that the SeNPs are uniform and in spherical shape of size 40-60 nm. The crystalline nature of SeNPs is assured by XRD analysis. The antibacterial property of synthesized SeNPs was tested against the pathogenic bacteria, i.e., Bacillus subtilis, Bacillus cereus, Escherichia coli, Staphylococcus pneumoniae, Proteus mirabilis and Klebsiella pneumoniae. SeNPs showed more antibacterial activity against B. subtilis (19 mm) and Streptococcus pneumoniae (15 mm) as compared with commercially available antibiotics such as streptomycin and erythromycin. The SeNPs synthesized via this process has proficient antimicrobial activity against pathogenic bacteria. SeNPs could play a significant role in pharmaceutical industries for the development of efficient antibiotic agents.