Nano LIFE

Biopolymer-based superabsorbent nanohydrogel consisting of N-isopropylacrylamide and itaconic acid (IA) was grafted on to starch backbone in an aqueous solution in the absence of the cross-linker agents. The copolymerization reaction occurred in the presence of ammonium persulfate (APS) as an initiator. The effect of N-isopropylacrylamide-to-IA ratio and different concentrations of initiator were investigated. The nanohydrogel composition was characterized by Fourier transform infrared spectroscopy (FTIR). The thermal stability was analyzed by Thermogravimetric analysis (TGA). Differential scanning calorimetry (DSC) studies were employed for determination of lower critical solution temperature in hydrogels. Dynamic light scattering analysis showed a narrow size distribution around 70–200nm for the synthesized nanohydrogels. The effects of pH on swelling behavior of the hydrogel were investigated. The obtained nanohydrogels, due to their pH and thermo dual sensitive properties, have the potential to be used in the drug delivery systems.

Magnetic nanoparticle hyperthermia uses magnetically-induced heat to kill cancer cells. In an alternating magnetic field, the induced heat depends strongly on particles’ absorption properties. In order to achieve and maintain therapeutic temperatures inside a tumor and to minimize damage to normal tissues due to induced eddy currents, there is a need to develop new magnetic nanoparticles with improved heating characteristics. This paper investigates the magnetic heating properties of composite iron-cobalt ferrite nanoparticles Co_xFe${}_{}^{\mathrm{\text{II}}}{}_{1-x}$Fe${}^{\mathrm{\text{III}}}{}_2$O₄ with 0$\le x\le 1$. These composite materials are synthesized using a precipitation method. First, the Fe-Co nanoparticle synthesis is described, then their structure, size, magnetic and heating properties are measured and analyzed. The resulting nanoparticles were treated at temperatures 100–600${}^{\circ }$C in order to study any structural transformations and changes of physical properties. Finally, an empirical model is used to calculate both the nanoparticles’ coercivity and their specific absorption rates for different Co concentrations.

In this study, we report the successful preparation of hematite nanostructures coated with thin titania layer for potential solar water splitting applications. The prepared samples were studied systematically by a range of analysis techniques. We showed that resulting hybrid hematite-titania nanosystem exhibited improved photoelectrochemical activity for solar water splitting compared to the bare hematite only. We also showed that this enhancement was achieved through an improvement in light harvesting and better charge carrier separation. Thus, these findings may open new perspectives for the development of photoelectrodes used in photoelectrochemical water splitting applications.

Effective design of nanoparticle systems can have a significant impact on therapeutic delivery. Physicochemical factors including size, shape and surface chemistry of nanoparticles can play a significant role in determining the efficacy of drug and gene delivery to cells. Polymeric as well as inorganic nanoparticle systems have been investigated as vehicles for nonviral gene delivery of transgenes. However, a head-to-head comparison of these different systems is largely lacking. In this study, we compare three related delivery systems, polymer, polymer-templated gold nanospheres and polymer-coated gold nanorods, for their respective in vitro transgene expression efficacies. Significant differences were seen in the hydrodynamic diameter and zeta potential for each of these different vehicles. Nevertheless, transgene (luciferase) expression efficacies and cytotoxicities were found to be similar for these three vehicles under different conditions. Our results indicate that polymeric systems can be used for synthesis or modification of nanoparticle systems with negligible variations in their transgene expression efficacies. This can have significant implications for generating polymer-nanoparticle theranostic systems that maintain therapeutic (e.g., nucleic acid) delivery efficacies, while also possessing additional functionalities, including

Gold nanoparticles (AuNPs) as one of the most stable metal nanoparticles have demonstrated extensive applications in recent years. This paper will give a focus on the AuNPs as biosensors, due to their inertness, unique optical properties, high surface area, and various surface functionalization methods. Synthesis of AuNps and the surface functionalization will be discussed in the first part. The size, shape, and stability can be controlled by different synthetic methods, while reductant usually needed. By surface functionalization with different molecules such as polymers, nucleic acids, and proteins, AuNPs will aggregate when specified molecule linkages showing up enables selective detections. The application in biosensing to detect proteins, oligonucleotide, glucose, and heavy metals will be exemplified, followed by the summary and future perspective part in the conclusion.