Nanoscience & Nanotechnology-Asia - Volume 13, Issue 5, 2023

Background: Brain tumor is the deadliest to treat with conventional drug therapy as it has various side effects on patients leading to organ failure.Objectives: It is difficult to treat brain cancers or deliver drugs to the targeted organ due to the numerous challenges faced. The current cytotoxic drugs have serious side effects, such as causing extreme damage to healthy cells, anemia associated with bone marrow suppression, constipation, small intestine infection, inflammatory responses, immunodeficiency, and multiorgan toxic effects. Low solubility, poor cell penetration, hepatic disposition, narrow therapeutic index, and rapid uptake by normal tissues are also a few challenges. To overcome these issues, it is important to choose plant-based drugs in nano-formulations to inhibit tumor cell growth without harming the normal cells of an individual. The biggest challenge in treating tumors is multidrug resistance, which can be overcome by choosing combination therapies of drugs based on phytochemicals and chemotherapeutic agents, which may lead to minimized adverse effects on patients with brain tumors.Results: As the use of nano-technology for targeted delivery enhances the performance of chemotherapeutic agents, the drugs with poor characteristics can further be encapsulated in nano-carriers and easily delivered to the poorly accessible areas of the brain.Conclusion: Based on the current progression in nanoformulations, so many new therapeutic approaches are available to provide better therapeutic results. However, there seems to be a multitude of issues that need to be addressed in order to ensure efficient results in treating cancer and thus lessening the fatality rate.

Silicon has been the most trusted and used material in the fabrication of microelectronics components and systems. Recently, silicon nanowires have gained a lot of importance in the development of devices/components in many applications. SiNWs have unique attributes that are not found in bulk silicon. Their one-dimensional electronic structure provides interesting properties. Unique properties and small dimension (nm) of silicon nanowires have made them to be used as sensing elements in the development of nanosensors and devices. Silicon nanowires are now being extensively used in the development of biosensors, FETs, lithium-ion batteries, transistors, microelectronic chips, and sensors. SiNWs are used in the development of solar cells and photovoltaic batteries, because of their charge-trapping capabilities. The fabrication of silicon nanowires follows chemical etching, chemical vapor deposition (CVD), electron beam lithography, etc. The dimensions of silicon nanowires are highly compatible with the dimensions of biological and chemical species, hence making them more efficient to be used as sensing elements in bio and chemical domains. SiNWs exhibit excellent piezoresistive properties and hence are used as piezoresistors in piezoresistive sensing applications. This article presents a review of SiNWs in the development of sensors. An emphasis is given to the piezoresistive property of SiNWs. The use of SiNWs as a piezoresistor in the development of piezoresistive pressure sensors is also extensively reviewed in this article, along with the unique properties of SiNWs. Typical dimensions and applications of SiNWs are also reviewed. Moreover, this article also explores the fabrication, characterization aspects, and capabilities of SiNWs in the design and development of nanoscale devices/sensors.

Background: The research on poorly aqueous-soluble drugs of BCS class II such as Cilnidipine (CLD) demands significant improvement in their aqueous solubility and dissolution rate. Such requirements may be fulfilled by adapting the nanocrystal approach with considering the various challenges.Objective: The prime purpose of this research work was to develop, optimize and characterize the nanocrystal of the poorly aqueous soluble drug (CLD) using the antisolvent-precipitation ultrasonication method. Such a method was followed for rapid re-dispersion of drugs in water with improving their dissolution rate.Methods: In this study, the different nanosuspension formulations were prepared using varying concentrations of three stabilizers - Pluronic F-68, Pluronic F-127, and HPMC-15cps, as selected stabilizer candidates. The selected and optimized formulation was followed by a lyophilization process with the incorporation of two selected distinct cryoprotectants - Mannitol and Lactose. The obtained nanocrystals were evaluated for their physical appearance, aqueous re-dispersibility, and particle size. Additionally, the optimized nanoformulation was also evaluated for morphology, dissolution rate, assay, drug entrapment efficiency, and drug loading content. The in vitro dissolution of optimized drug nanocrystal was done in the phosphate buffer solution of pH 6.8 and compared with bulk CLD and a physical mixture of CLD and pluronic F-68.Results: For optimizing drug nanosuspension, the effect of pluronic F-68 and cilnidipine concentration was investigated, and the optimal values were 0.3% w/v and 5 mg/ml, respectively. Mannitol-containing nanocrystals exhibited a white crystalline powder having a particle size of 154 nm and a good polydispersity index (0.217). Nanocrystals also demonstrated an excellent re-dispersibility in deionized water after manual shaking and no particles were observed at the bottom of the container till 15 days. Such optimized formulation also indicated an increase in dissolution rate in comparison to bulk CLD and their physical mixture with pluronic F-68. It released approximately 72.25% of the drug within 90 minutes while bulk CLD and physical mixture released only 31.24% and 30.37% of the drug, respectively at the same time. The drug assay method indicated that only 92% of the drug was present in optimized nanocrystals after the transformation of nanosuspension into nanocrystals which was less than the initial amount. In this research, the experimental work also analyzed that optimized nanocrystal has only 28.6% of drug loading content.Conclusion: The selected method and cryoprotectant have ability to develop the aqueous re-dispersible nanocrystal for enhancing the dissolution rate and water solubility of CLD-like poorly soluble drugs.

Acne is one of the most prevalent skin conditions among adolescents, which can often continue to adulthood. It is characterized by the appearance of comedones along with blackheads, whiteheads, papules, pimples, and pinheads on the neck, face, and back. The most common cause of acne is the bacteria Propionibacterium acnes, but factors like hormonal imbalance, anxiety, and genetic makeup can often be responsible. Despite the availability of numerous anti-acne agents, their efficacy is often limited due to poor skin penetration and adverse effects. Nanocarriers have emerged as a promising approach for the targeted delivery of anti-acne agents to the skin. This review discusses the potential of nanocarriers, including vesicular systems, biphasic systems, polymeric systems, fullerenes, and carbon nanoparticles, for enhanced skin penetration and controlled release of anti-acne agents. Various studies have reported using nanocarriers to successfully deliver agents such as benzoyl peroxide, salicylic acid, and retinoids, resulting in improved efficacy and reduced side effects. Using nanocarriers has shown promise for developing combination therapies targeting multiple aspects of acne pathogenesis. However, further research is needed to optimize the formulation and assess the safety and efficacy of nanocarrier-based anti-acne therapies.

Aims: The present study examines the atomic-scale structures of Graphene Oxide (GO) and Reduced Graphene Oxide (RGO).Background: Electron microscopic studies on Sri Lankan vein graphite are considerably less; hence, this study focuses on the atomic-scale study of Sri Lankan vein graphite, using advanced electron microscopic techniques. Objective: The purpose of this research is to utilize the data obtained to explore the multidisciplinary characteristics of graphene to the maximum prospectively. Method: We report an atomic-scale study on Sri Lankan vein graphite (purest) derivatives using advanced electron microscopic techniques, including High-Resolution Transmission Electron Microscope (HRTEM), Scanning Transmission Electron Microscope (STEM), and Electron Energy Loss Spectroscopy (EELS). The present study examines the atomic-scale structures of Graphene Oxide (GO) and Reduced Graphene Oxide (RGO). Result: The results obtained exhibited an inter-atomic layer distance of 3.54 Å for RGO. The EELS study performed with the electron dose optimization for GO and RGO distinguished the differences in the C K edge with the oxygen functionalities. The XPS study confirmed the changes in oxygen functionalities obtained with EELS. Conclusion: The advanced electron microscopic techniques and other molecular spectroscopic analysis techniques allowed us to obtain a comprehensive study on Sri Lankan vein graphene-based structural and chemical features on an atomic scale.

MXene-based multicomponent materials are 2D substances derived from transition metal (M) with carbide/nitride combinations having several propitious uses, including the fabrication of highperformance electrode materials utilized in Lithium- ion batteries (LIBs), particularly for energy storage devices. The suitability of these new classes of materials for LIB electrodes can be attributed to their high conductivity combined with their excellent surface properties desirable for electrode applications, such as fast charge-discharge capability, high storage capacity and high rate capacity. However, there are several challenges possessed by MXene-based nanomaterials in the application of their electrodes in future flexible and wearable devices, demanding more research work and development strategies. After a brief overview of MXenes used in batteries, this paper deals with the synthesis, morphology-properties correlations, and their performance. Finally, this paper highlights the advantages, limitations, and challenges of MXene-based electrodes for LIBs, ending with concluding remarks.

Lipid based nanoparticle (LNP) structures commonly used for drug delivery already in clinical use are generally classified into three viz vesicular systems, emulsion based systems and lipid nanoparticles. The details of the types, basic structural characteristics in drug delivery, clinical trials, and patents have been discussed in this work. Moreover, despite the therapeutic efficacies of LNPs, there are some toxicity challenges associated with their use. These toxicities may be cytotoxicity or genotoxicity; to overcome some of these challenges, some measures could be taken during preformulation stages in order to circumvent it. These measures have been extensively discussed in this work. LNPs are used in the targeting of immune cells, which are direct participants in a variety of diseases, hence, are attractive targets for therapy. Cell specific targeting of therapeutic agent(s) helps to concentrate and localize the therapeutic effect and, hence, lowers the systemic side effects, while simultaneously increasing the management outcome. Nanotechnology and particle engineering helps distinguish each immune cell from the other to deliver therapeutic agents and ensure in vivo stability as well as sustained drug release. Surface modification of LNP is an important characteristic utilized in targeting therapeutic agents and allows the utilization of various specific properties expressed in each immune cell. These targeting strategies have been explored in this work exhaustively, and some of the companies and academic labs that develop LNP have been discussed. Also, new ways of developing novel patentable LNP have been discussed.