Novel Biodegradable Films with Extraordinary Tensile Strength and Flexibility Provided by Nanoparticles

A simple method has been proposed to synthesize environmental friendly biodegradable starch films containing gold (Au) and cadmium sulfide (CdS) nanoparticles (NPs) with significantly improved mechanical properties than pure starch films for various industrial applications. Au NPs were synthesized in vitro by using starch as a weak reducing agent simultaneously for the starch film formation. All reactions were monitored with UV–visible measurements, and it was observed that the growth of Au NPs was proportional to the amount of starch. Due to the inherent surface plasmon resonance (SPR), all Au NP starch films were UV active. Likewise, CdS NPs were synthesized in the glycerol medium and further incorporated in the starch films to make fluorescent active films. X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM), and differential scanning calorimetry (DSC) measurements were used to characterize NPs as well as starch films. A systematic measurement of mechanical properties showed a high degree of tensile strength and flexibility for CdS fluorescent starch films in comparison to Au NP starch films that made the former an ideal candidate for various industrial applications

Green Chemistry of Zein Protein Toward the Synthesis of Bioconjugated Nanoparticles: Understanding Unfolding, Fusogenic Behavior, and Hemolysis

Green chemistry of industrially important zein protein was explored in aqueous phase toward the synthesis of bioconjugated gold (Au) nanoparticles (NPs), which allowed us to simultaneously understand the unfolding behavior of zein with respect to temperature and time. Synthesis of Au NPs was monitored with simultaneous measurements of UV–visible absorbance due to the surface plasmon resonance (SPR) of Au NPs that triggered the adsorption of zein on the NP surface and thus resulted in its unfolding. Surface adsorption of zein further controlled the crystal growth of Au NPs, which relied on the degree of unfolding and fusogenic behavior of zein due to its predominant hydrophobic nature. The latter property induced a marked blue shift in the SPR rarely observed in the growing NPs during the nucleation process. A greater unfolding of zein in fact was instrumental in generating zein-coated faceted NPs that were subjected to their hemolytic response for their possible use as drug release vehicles. Zein coating significantly reduced the hemolysis and made bioconjugated Au NPs the best models for biomedical applications in nanotechnology