Current Nanoscience - Volume 19, Issue 3, 2023

This review focuses on nerve degeneration a major health problem of nowadays, caused due to different nerve diseases or injuries. The low regenerative capacity of the nerve leads to primary brain injury. Clinical therapies available were only able to stabilize lesion progression. Reversal of the degeneration process and functional regeneration promotion were brought about by the implementation of nanotechnology in biology, allowing cell tissue integration. Nanomaterials implemented in the delivery of drugs and bioactive materials treat specifically targeted cells. Nanomaterials made in contact with cells lead to stem cell therapy, promoting stem cell differentiation and neurogenesis. Nanomaterials were also screened for their appropriateness as potential scaffold materials, owing to their neuroprotectant activity in nerve regeneration.

Neurodegenerative disorders are characterized by the progressive, irreversible deterioration of functions of the central nervous system, especially neurons, that lead to cognitive, motor, and intellectual impairment. Alzheimer's disease (AD) and Parkinson's disease (PD) are the most prevalent forms of neurodegenerative disorders and are predicted to be leading causes of mortality. Although conventional formulations are available for symptomatic treatment of AD and PD, many novel formulations and routes of administration are persistently studied for their better management, and nose-to-brain delivery is one of them. This platform has been explored with various nanoformulations for targeted brain delivery. Lipid nanocarriers are known for bypassing the blood-brain barrier (BBB) through nasal delivery, and several drugs have been evaluated in the lipid carrier system. This review focuses on various lipid-based nanocarriers such as liposomes, solid lipid nanoparticles, nanostructured lipid carriers, microemulsions, nanoemulsions, micelles and cubosomes reported to treat and alleviate the symptoms of AD and PD via nasal route. It gives an overview of key findings of nasal lipid-based nanocarriers and their improved pharmacokinetic parameters and enhanced neuroprotection that may be utilized in the future to explore it commercially.

As a precious sterile body fluid, cerebrospinal fluid (CSF) examination plays an important role in the diagnosis of many clinical diseases. Early diagnosis can significantly improve these diseases' survival rate. Raman spectroscopy is a scattering spectrum that has been used for the research and analysis of molecular structures. It has been widely used in many fields, such as protein detection, tumor genes, microbiological pathogen compound materials, and food and medical monitoring, with high sensitivity and specificity. In this review, we briefly introduce the mechanism of Raman spectroscopy and summarize its progress in detecting cerebrospinal fluid, mainly focusing on the application of neurodegenerative diseases by Raman spectroscopy. Meanwhile, we also prospect the development of Raman spectroscopy in the detection of CSF and other fluids.

Central nervous system disorders, particularly neurodegenerative disorders, are a serious public health concern that researchers must address to protect the persons against them. The prevalence of the blood-brain barrier (BBB), which segregates the blood from cerebral parenchyma and hence limits the brain uptake of most of the therapeutic agents, makes developing drug delivery systems for brain delivery one of the most challenging research subjects in pharmaceutical domains. The detailed description of BBB-crossing nanotechnology in this article is expected to pique the attention of researchers from a wide range of fields who want to help build powerful BBB-crossing nanosystems for highly effective brain targeting. Recent advances in nanotechnology have resulted in multifunctional nanosystems that can cross or circumvent the BBB, allowing for more accurate assessment and treatment of brain tumours. The application of nanotechnology in targeting different drugs across the brain is included in this review.

The current review is focused on many carrier systems and technologies that have recently been explored for achieving controlled drug release, promoting therapeutic potential, and selectivity. Among various carrier systems, the vesicular drug delivery system is the highly effective method of delivering medication to the infection site resulting in minimal drug toxicity and adverse effects. Various research studies have been conducted to reduce drug loss and degradation, prevent unwanted side effects, improve drug bioavailability, and retain the fraction of drugs in the necessary region. To achieve these goals, novel vesicular drug delivery and vesicular drug targeting systems, such as ufasomes and ufosomes, are currently under research. They are highly ordered, self-assembled novel vesicular drug delivery systems formed from disordered building blocks into highly ordered systems by specific inter-block mutual interactions. These two carrier systems are separately being studied for their efficacy to improve the effectiveness of various drugs. In this perspective, we summarized the basic concept and recent studies on ufasomes and ufosomes for drug delivery, along with pertinent investigations in the present review. The vesicular systems discussed in this article are given chronologically, from existing systems to advanced fatty acid vesicles. Drug design and development using ufasome and ufosome vesicular systems have added a new dimension to the treatment of disease conditions by circumventing penetration, limiting obstacles and, therefore, increasing efficacy.

The molecularly imprinted polymers (MIPs) technology, which has been around since the 1970s, has grown in popularity in recent decades. MIPs have shown to be a useful approach for determining target molecules in complicated matrices containing other structurally similar and related chemicals. Despite MIPs having intrinsic polymer features such as stability, robustness, and low-cost production, traditional MIPs have a number of drawbacks. Surface molecular imprinting appears to be an alternative approach that can address some of the drawbacks of traditional MIP by anchoring shells to the surface of matrix carriers such as nanoparticles. The incorporation of nanoparticles into the polymeric structure of MIPs can improve their properties or provide novel capabilities. Magnetic nanoparticles have been widely explored for their separation and extraction capability. Magnetic components in MIP can help develop a regulated rebinding process, allowing magnetic separation to substitute centrifugation and filtration stages in a simple, costeffective strategy. Polymers are created directly on the surface of a magnetic substrate to create a unique material termed magnetic molecularly imprinted polymer (MMIP). These materials have been widely used to extract molecules from complex matrices in a variety of applications, especially in environmental, food, and biological studies. This paper seeks to summarize and discuss the nanoparticle synthesis and magnetic nanoparticle combination in the MIP preparation. The novel applications of MMIP in environmental, food and biological analyses are also discussed in this paper.

Background: The NOX (e.g. NO2) is harmful to human health and environmental quality. It is of great interest to monitor the hazardous NOX with a simple, reliable, and sensitive sensor. Currently, the commonly used detection methods have disadvantages of complex operation, unstable cycling performance and low sensitivity. Objective: In this paper, rGO coated Ni foam supported MnO2 is synthesized to develop a more advanced detection method for the rapid analysis of NO2. Methods: A three-dimensional nickel foam supported MnO2 and rGO (MnO2/rGO@NF) was prepared by a hydrothermal method for application in binder-free electrode of NO2 sensor. Results: The MnO2/rGO@NF composite displayed significantly better NO2 sensing performance compared to single MnO2@NF or rGO@NF. The excellent sensing response (5.9%) as well as high cycling stability were observed in the presence of 50.0 ppm NO2 at room temperature. Furthermore, the mechanism of the great gas-sensing performance was also investigated by the density functional theory (DFT). Conclusion: These results were very important to further design and prepare new sensitive materials applied in binder-free electrode of gas NO2 sensors.

Background: Enterotoxigenic E. coli (ETEC) can be considered the main cause of traveler’s diarrhea, which is affecting children in developing countries. The bacterium has several virulence factors, including colonization factors (CFs), heat-labile (LT), and heat-stable (ST) toxins. The World Health Organization has designated the development of an ETEC vaccine one of its top goals due to the disease's rising antibiotic resistance and deteriorating access to sources of clean drinking water. Objective: The objective of this study is to investigate the oral immunogenicity of chitosan nanoparticles (CNPs) encapsulated CCL protein containing CfaB along with STa toxoid, CfaE, and LtB. Methods: The E. coli BL21DE3 harboring pET-28a-ccl vector was used for protein expression. After purification and confirmation, the protein was encapsulated in CNPs and the particle size was measured. Immunogenicity was assessed by evaluating antibody titers after BALB/c mice vaccination. Finally, the neutralization efficiency of immunized mice sera was evaluated by a rabbit ileal loop test. Results: The purified protein (~57kDa) was confirmed by Western blotting and the size of CCLCNPs was measured with an average of 112.0nm with 98.8% of encapsulation efficiency. CCLCNPs are able to stimulate the immune system by providing suitable titers of antibodies. The fluid accumulation in the rabbit’s intestine was significantly reduced. Conclusion: The CCL-CNPs can be considered a candidate for producing oral nanovaccine.

Background: With the continuous development of computer science, data-driven computing methods have shown their advantages in various fields. In the field of photonics, deep learning (DL) can be used to inversely design the structure of optical devices. Objective: The two-dimensional (2D) photonic crystal (PCs) with adjustable structural parameters and a large complete photonic band gap (CPBG) are inversely designed in terms of DL neural network (NN) tagged to obtain a specified width of CPBG. Methods: The new PCs structure is designed by combining multiple factors that produce a CPBG. Tandem networks are used to speed up the training of the NN and tackle the problem of nonuniqueness that arises in inverse design. Results: After various attempts and improvements, the ideal PCs structure was obtained. It is found that the connecting channel between the primitives in the PCs unit cell has a dominate effect on the CPBG. The use of a tandem network enables better convergence of the network. Finally, suitable NN can be obtained, which can realize the forward prediction of the CPBG and the inverse design of the structure. Conclusion: DL can realize forward prediction and inverse design of 2D PCs targeting the width of the CPBG, which broadens the application scope of DL in the field of PCs.

Aims: This work uses the MACE method to synthesize SiNWs- NiNPs/NiONPs to degrade organic pollutants by photocatalysis. Background: Photocatalytic degradation has been applied as an attractive solution to remove several organic pollutants. Heterostructured nanomaterials have become an interesting platform for investigation. Metal-assisted chemical etching (MACE) stands out as a promising technique because it is simple, low cost, and fast. Objective: Attain the degradation of methyl orange (MO) in the presence of silicon nanowires (SiNWs) in heterojunction with Nickel/Nickel Oxide nanoparticles (NiNPs-NiONPs). Methods: SiNWs were synthesized by metal (Ag) assisted chemical etching (MACE) of monocrystalline silicon wafers. NiNPs were non-electrolytically deposited on the SiNWs (electroless method). The morphology of the SiNWs- NiNPs/NiONPs was observed by SEM. Results: Heterogeneous photocatalytic degradation of methyl orange (C14H14N3NaO3S) in an aqueous solution at a concentration of 20 ppm had an efficiency of 66.5% after 180 min under UV irradiation. The MO degradation percentage was determined using UV-visible spectrophotometry. Conclusion: The SiNWs-NiNPs/NiONPs were obtained composed mainly of Si covered by SiO2 decorated on the tips with Ni (II) in the form of NiO and a small amount of nickel metal. The removal efficiency obtained at 180 min of light exposure was 66.5%. After the photocatalysis tests, further oxidation of the NiNPS into NiONPs, was attributed to the reactive oxygen species in the aqueous medium based on the changes of the oxygen and Ni2p3/2 peaks by XPS. Other: Through XPS, the oxidation state of the SiNWs- NiNPs/NiONPs was analyzed.

Introduction: Taking the typical human telomeric G-quadruplex (G4) sequence as a reference, we designed four photoresponsive DNA sequences by inserting azobenzene moieties into a planar interlayer and the end surfaces of the G4 structure. Methods: The photo-responsive G4 molecules were investigated by melting curve, FRET, CD, and gel electrophoresis. Results and Discussion: The measurements showed that the photo-responsive G4 molecules took the stable four-strand structure under visible light, but after UV light irradiation, the G4 structures tended to be disentangled. When azobenzene molecules were inserted at the end surfaces of the G4 structure, the Tm difference of the photo-responsive G4 between visible light and UV light reached more than 30 ºC. Conclusion: In a temperature range from 20 to 53 ºC, the reversible transformation of the G4 structure can be realized solely by light irradiation.

Background: The efficient removal of the environmental organic pollutants using the photocatalytic technology catalyzed by semiconductors has attracted great research interest in recent years. La2O3/SrSn(OH)6 nanorods show enhanced photocatalytic activity towards crystal violet (CV). Objective: The aim of this study is to obtain La2O3/SrSn(OH)6 nanorods by a simple hydrothermal route using lanthanum acetate and SrSn(OH)6 nanorods, and explore the photocatalytic properties for CV degradation. Methods: La2O3/SrSn(OH)6 nanorods were obtained by a hydrothermal route using lanthanum acetate and SrSn(OH)6 nanorods and characterized by X-ray diffraction (XRD), transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) and photocatalytic experiments. Results: The composite nanorods comprise hexagonal SrSn(OH)6 and cubic La2O3 phases. Some nanoscale particles attach to the surface of the nanorods with a diameter and length of about 100 nm and 1 μm, respectively. La2O3/SrSn(OH)6 nanorods show a lower band gap value than the SrSn(OH)6 nanorods. The photocatalytic reaction rate constant for the CV degradation using 15wt.%- La2O3/SrSn(OH)6 nanorods is 3 times higher than that of the pure nanorods. Conclusion: La2O3/SrSn(OH)6 nanorods possess good reusability and stability for CV removal. The photocatalytic activity for the CV removal of the SrSn(OH)6 nanorods can be greatly enhanced by La2O3.