Nano-hydroxyapatite/collagen composite as scaffold material for bone regeneration.

Regenerative medicine is one of the applications of tissue engineering technology that has upsurged the hope of reforming defective organs, especially bones. Bone regeneration is a natural process but becomes complicated under trauma and disease conditions. Even though there are various conventional methods, the usage of scaffolds serves to be a promising technique where they act as the supporting material and the necessary nutrient factors are supplemented alongside, which facilitates the attachment and growth of cells over the scaffold's surface. Human bone is mainly comprised of a hydroxyapatite (HA)/collagen complex. Recently, reports validated that the HA in the nano regime showed higher cell adherence and subsequent growth. Therefore, while using nano-HA/collagen complex as a scaffold material, the limitations of conventional routes of bone regeneration can be minimized. In this context, the present review focuses on the use and fabrication of nano-HA/collagen complex as a scaffold material for the bone regeneration process.

Bioconjugated gold nanoparticles as an efficient colorimetric sensor for cancer diagnostics.

The chances of curing and reducing the adverse effect of cancer partly lie in early detection. Colorimetric sensor-based technique show promising results since the target is detected with high sensitivity but without the use of advanced/costly techniques through a simple visual color change. In most cases, gold nanoparticles (Au Nps) functionalized with biomolecules complementary to target analyte are used for colorimetric detection. The interaction of functionalized Au Nps with target analytes induce aggregation or dispersion where the color of the solution changes from red to blue or blue to red respectively, which can be visualized by the naked eyes. Such a facile technique has a high commercial viability and therefore, understanding its concept is essential. Here, some of the reported studies are discussed technically for better understanding about the invitro colorimetric detection of cancer.

Improving electrochemical performance of reduced graphene oxide by counteracting its aggregation through intercalation of nanoparticles.

Herein, we report the fabrication and characterization of hybrid electrode material for supercapacitor applications. CaCO3 nanoparticles (Nps) are used as intercalator to avoid the restacking behavior of reduced graphene oxide (rGO) nanosheets. CaCO3 Nps and rGO sheets are fabricated employing precipitation technique and microwave irradiation method, respectively. The intercalation process is performed by magnetic stirring followed by ultra-sonication technique. As prepared CaCO3 Nps, rGO and rGO intercalated with 2.5 wt.% and 5 wt.% CaCO3 Nps are characterized using X-ray diffraction analysis, Fourier transform infrared spectroscopy and field emission scanning electron microscopy to evaluate the crystalline characteristics, molecular vibrations, and morphology, respectively. The prepared electrode materials are coated separately on the glassy carbon electrode and their electrochemical performance displayed remarkable capacitance values for rGO nanosheets intercalated with 2.5 wt.% and 5 wt.% CaCO3 Nps. From the obtained results, it is clear that the specific capacitance of 2.5 wt.% CaCO3 intercalated rGO displays higher specific capacitance of 84.5 F/g at 5 mV/s with high retention stability. The mechanism behind the improvement in the electrochemical behavior is due to the increase in active surface area which is explained via Brunauer-Emmett-Teller analysis and energy-dispersive X-ray spectroscopic analysis.

Alkyd resin based hydrophilic self-cleaning surface with self-refreshing behaviour as single step durable coating.

Herein, we reported the photo-catalytic degradation/anti-bacterial property of Ag-doped ZnO nanoparticles (SDZO Nps) prepared by a facile gel-combustion technique and its self-cleaning/self-refreshing/self-disinfectant behaviour while on impregnating as pigment into the alkyd resin based coating. The influence of doping Ag (1% & 2%) with ZnO has been evaluated in terms of crystal structure, morphology, optical properties, etc. using X-ray diffraction analysis, Field Emission Scanning Electron Microscope, UV-Vis analysis, and Photoluminescence spectra. The photo-catalytic degradation of crystal violet solution by SDZO Nps is spectroscopically followed employing UV-Vis spectroscopy. From the obtained results, the rate of degradation of 1% SDZO Nps is found higher than that of other samples under sunlight illumination; degrading 1 mg of crystal violet in 30 min. Thus, implementing the synergic effect of nano ZnO and the doped Ag provides a suitable pathway for the development of high efficient photo-catalyst. Further, alkyd resin based self-cleaning coating is formulated using 1% SDZO Nps as pigment along with other additives; the contents are milled to form a homogeneous mixture by high energy ball milling technique. Crystal violet solution coated over dried alkyd coating gets decolorized on exposure to sunlight indicating the mineralization of pollutants and proves the fact that the as obtained coating possess self-cleaning nature. Besides the self-cleaning property, the coating exhibits self-refreshing property which is essential for the long lasting self-cleaning activity. Further, the disinfectant properties of 1% SDZO Nps and 1% SDZO Nps impregnated coating have been evaluated against gram negative Escherichia coli bacterial strain. The acquired experimental outcomes suggest the potential use of self-cleaning coating to keep the environment clean and hygienic economically.