Nanoscience & Nanotechnology-Asia - Volume 13, Issue 3, 2023

Aim: The purpose of this study is to examine the evidence for the efficiency of nanoparticles (NPs) incorporated into orthodontic materials (brackets, bonding agents, wires, acrylic resin, and elastics) in order to enhance their antimicrobial properties. Materials and Methods: A comprehensive search strategy was conducted in electronic databases like PubMed, Cochrane, and Google scholar, books, grey literature like unpublished literature, dissertations, conference reports, etc. Finally, out of all the literature reviewed, a total of 30 articles met the inclusion criteria and were included in the qualitative analysis. For the quantitative analysis, a total of 6 articles were used. Results: Antimicrobial agents such as silver nanoparticles, Titanium dioxide, Silver platinum alloy, zinc oxide and copper oxide, quaternary ammonium dimethacrylate (QADM), Hydroxyapatite crystals, and silver, quaternary ammonium polyethyleneimine (QPEI) particles, silica, and titanium have been incorporated in various orthodontic materials. The incorporation of these nanoparticles into orthodontic materials led to a significant increase in the antibacterial capacity when compared to controls used in the various studies. Conclusion: It can be concluded that the incorporation of nanoparticles into orthodontic materials improves their antibacterial properties. Due to the heterogeneity observed across the studies reviewed, further research with standardized study protocols in terms of the size, concentration, and techniques of incorporation of different NPs into various orthodontic materials is pertinent.

Objective: The localized surface plasmon resonance (LSPR) and field enhancement of Gold nanosphere and nanostar were evaluated. Method: FDTD solutions, a product of Lumerical solutions Inc., Vancouver, Canada [17], was used to perform the electromagnetic simulations in this work. The impact of particle size and spike number on peak wavelength was studied quantitatively. Result: By altering the particle size and amount of spikes, we were able to detect a hot zone around nanostar. For Au nanostar, the peak wavelength for nanostar varies from visible to near-infrared. When compared to a nanosphere of the same dimension, the shift seen in nanostar is substantially higher, making it more suitable for biosensing applications. When the refractive index of the surrounding medium is increased, a red shift in peak wavelength is noticed, forming the basis for a plasmonic refractive index sensor. Aside from having a higher sensitivity, nanostar has a twofold hot spot system due to their unique surfaces. There is no evidence of spike aggregation in the near field pattern. As a result, it is thought to be a better nanostructure for biosensing applications. Conclusion: The LSPR and field enhancement for Au nanosphere and Nanostar were investigated using the FDTD method. The nanosphere's peak wavelength is in visible region, whereas the nanostar's range extends from visible to near-infrared, depending on the size and number of spikes. At 517 nm, the enhancement factor for a nanosphere was 10², but at 1282 nm, the enhancement factor for a nanostar with six spikes was 10⁸.

Background: The correlation between anodization conditions and the ageing effect on TiO2 nanotubes (TNT) surface has been widely studied in different media and conditions (physiological solutions, mechanical stresses in water, etc.) for the prediction of their behaviour over a long period of time. In the present study, the synthesized TiO2 nanotubes (TNT) from Ti-6Al-4V alloy, which were left unattended and exposed to environmental conditions (i.e., humidity and ambient temperature) for more than 4 years, were investigated to underline any important alteration/changes and ageing effects, on the surface morphology, the surface composition, and the electrochemical behaviour. The nanotubes were made in 2018 by anodization in different potentials (20V, 40V, 50V, and 60V) for different times (30 min, 60 min, 90 min, 150 min and 180 min) in an Ethylene Glycol solution for other purposes. Methods: For the surface morphology characterisation, electronic microscopy (SEM) was performed to depict any tendency with anodization conditions: potential and time. The comparison study between the obtained results and the SEM pictures taken on similar samples made and characterized under the same conditions in 2018, reveals a noticeable alteration in the morphology and a change in the TNT’s external diameter. Surface composition was checked using energy dispersive spectrometry (EDXS). The EDXS spectra analysis was realised to investigate the storage time impact on structure surface stability. A drastic decrease in the amount of oxygen was noticed on all of the surfaces where wettability measurements by contact angle were performed to confirm the latter. The verification of the hydrophobicity of TNT surfaces attested that all aged samples are hydrophobic in concordance with EDXS analysis and X-ray photoelectron spectroscopy (XPS). To affirm the surface modification during the storage duration and its impact on the electrical behaviour: cyclic voltammetry (CV), open circuit potential (OCP) measurements, and Tafel plots are undergone on the aged samples and compared with the freshly synthesised samples. The plotted CV curved as a function of the scan rate and the composition of the electrolyte showed a correlation between the different samples electrochemical behaviour and their surface morphologies as well as the existence of surface states for all samples. Results: From the previous characterisation, it was obvious that the sample prepared at 40V over 3 hours showed a remarkable electrochemical behaviour. The ageing effect is closely related to the anodization conditions. It was also noticed that the amount of water in the electrolyte solution EG played a contributing factor in the onset of ageing. High water content causes the formation of nanograss which have a non-negligible influence on the morphology. Exposing nanotube surfaces to ambient conditions without taking any precautionary measures and without knowing their historical anodization conditions can cause drastic changes in the electrochemical behaviour of TNT. These changes affect considerably their function for different applications. Conclusion: These results can open a new way for the optimization of the storage conditions according to anodization conditions (electrolyte, voltage, time, and temperature annealing) of this material as well as for the study of the life cycle of products made from TiO2 nanotubes.

Background: Despite the awareness among patients with complete dentures, the risk factor for developing denture related candidiasis is when it is not removed during sleep and cleaned regularly. The routine treatment is an antifungal application, but frequent infection is seen after treatment. Nanotechnology has led the medical field to a cutting edge in most of the treatment aspects of various conditions. Moreover, the assimilation of silver nanoparticles into the polymer can be useful as an antifungal agent. To assess the antifungal efficacy of AgNP’s/ PMMA (silver nanoparticles /polymethlmethacrylate) against Candida albicansstrain and to evaluate the continuous release of silver ions which would increase antifungal mechanism. Methods: Chemical methods of synthesis of silver nanoparticles using metal precursors, reducing agents, and stabilizing agents were used because of its convenience and simple equipment. MIC (minimum inhibitory concentration) was evaluated along with antifungal efficacy by incorporating PMMA (polymethylmethacrylate) discs with silver nanoparticles. Silver ion release was carried out by immersing the PMMA/Ag discs in deionised water for different immersion periods. Results: In the Independent Sample ‘t’ test, the comparison of optical density between the study groups at 6 months at absorbance A230, A260,A280, A320, A420, and A550 was statistically significant (p < 0.05). Conclusion: Silver Nanoparticles could be prepared which is cost-effective and can serve as an antifungal agent against Candida albicans. Silver ion release was seen with AgNP’s /PMMA (SilverNanoparticle /polymethylmethacrylate) at 6 months and Group A (.06M) and Group B (.03 M) was confirmed to be used as an antifungal agent.

Hydrogels are one of the most extensively studied novel drug delivery dosage forms owing to their satisfactory results in drug delivery in various conditions, including pain management, immunomodulation, carcinomas, healing of wounds, and cardiology. A crosslinked polymeric network and an optimum amount of water combine to form hydrogels. Due to their specific properties such as biocompatibility, biodegradability, hydrophilicity, and non-toxic to biological tissues, hydrogels are demanding biomaterials. Furthermore, due to their programmable physical characteristics, controlled degradation behavior, and capability to preserve unstable medicines from degradation, hydrogels serve as an advanced drug delivery system in which diverse physiochemical interactions with the polymeric matrix containing embedded medications control their release. Despite significant challenges remaining, there has been significant progress in recent years in overcoming the clinical and pharmacological constraints of hydrogels for drug delivery applications This review covers various hydrogel-forming polymers, strategies for crosslinking of gelling agents, and release mechanisms from the hydrogel. Moreover, the current work includes a few marketed hydrogel preparations and patent rights associated with it, describing its mechanism of action against the underlying diseases.

The primary cause of death worldwide is an infectious disease, and viruses in particular, have a major worldwide impact on health and economic growth. A critical public health problem is the quick emergence of medication resistance to currently accessible treatments as well as negative side effects from repeated use. Therefore, the creation of novel treatment plans is necessary. In contrast to conventional chemical-based antiviral drugs, the use of nanoparticles offers an alluring potential for the development of innovative antiviral therapies with minimal risk of acquiring drug resistance. Nanomaterials make it simple to change the properties of accessible resources. Nanomaterials can be readily applied to modify the available detection platforms to improve their sensitivity. Due to their high surface-to-volume ratio, NPs readily bind to either the viral membrane proteins or the viral reproduction system (DNA/RNA), thus hindering the virus' ability to infect cells. Viral proliferation has been inhibited by the use of metal nanoparticles (NPs) such as gold, silver, and copper. Copper has repeatedly been examined for its strong anti-microbial qualities due to its lower cost than silver and gold. The virus's inactivation on copper surfaces after 4 hours raises the possibility that copper could be used to destroy the infection. Also, it was discovered that 50% of virus-like particles (VLPs) could be rendered inactive by copper composite nanoparticles in just 10 minutes. The medical community could benefit greatly from sophisticated smartphone and/or LFA-based detection techniques that can be used right at the patient's bedside. This review discusses methods based on nanotechnology for diagnosing and treating viral diseases, especially HIV and influenza.

Background: The separation efficiency of the electron and hole pairs of the BaSn composite nanorods is limited due to a wide band gap energy restricting the photocatalytic treatment ability of the composite nanorods. It is an efficient route to improve the photocatalytic properties of the semiconductor photocatalysts by La2O3 modification. Objective: This study aims to synthesize La2O3-modified BaSn composite nanorods through a simple method and research the photocatalytic performance of the La2O3-modified BaSn composite nanorods for crystal violet degradation. Methods: La2O3 modified BaSn composite nanorods were synthesized by a facile method using lanthanum acetate as the lanthanum raw material and evaluated by electron microscopy, solid diffuse reflectance spectra, X-ray diffraction, photoluminescence and photocatalytic measurement for crystal violet degradation under ultraviolet light irradiation. Results: BaSn composite nanorods consist of orthorhombic SnO2, monoclinic BaSn(OH)6, and monoclinic Ba(OH)2. La2O3 suppresses the growth of the monoclinic BaSn(OH)6, and orthorhombic SnO2. The La2O3-modified BaSn composite nanorods possess coarse surface covered with the La2O3 nanoscale particles with an average size of about 50 nm. The absorption edge red-shifts to 373 nm and the band gap energy reaches 3.32 eV of the La2O3 modified BaSn composite nanorods compared with the BaSn composite nanorods. 20 mL 10 mg·L^-1 crystal violet solution can be entirely removed by 20 mg composite nanorods with 15wt.% La2O3 content under ultraviolet light irradiated for 120 min. The reaction rate constant is 2.4 times higher than that of the non-modified composite nanorods. Hydroxyl radicals and holes are the reaction active substances for crystal violet degradation in the composite nanorod reaction system. Conclusion: La2O3 modification decreases the band gap energy, enhances the light absorption ability, and suppresses the recombination of the electron and hole pairs of the composite nanorods.

Medical nanotechnology is surfacing as a challenging arena covering new biomedical applications, such as drug delivery, treatment, nano diagnosis, controlled drug release, regenerative medicine, and disease prevention. The recent developments in the field of Nanotechnology have enabled the nanostructures to overcome the problems associated with drug delivery making them the promising agents for site-specific drug delivery with reduced side effects and the best treatment outcome. These nanodrug delivery systems are designed in such a way that they can breach the biological barrier and deliver the drug in a site-specific manner. They enhance the effectiveness of drugs by increasing the stability and water solubility of drugs and by increasing the rate at which these nano drug complexes are taken up by the cells and tissues. Dendrimers, nanocrystals, nano-polymer NPs, and liposomes are futuristic nano-based drug delivery systems. Smart polymers are future drug-delivery systems with cutting-edge precise technology that are employed in effective cellular targeting based on temperature, pH, photoresponsive, conductive and magnetic responsive smart polymers. This review provides a comprehensive view of various nanostructures and their application in drug delivery.