The recent advancement of low-dimensional nanostructured materials for drug delivery and drug sensing application: A brief review

In this review article, we have presented a detailed analysis of the recent advancement of quantum mechanical calculations in the applications of the low-dimensional nanomaterials (LDNs) into biomedical fields like biosensors and drug delivery systems development. Biosensors play an essential role for many communities, e.g. law enforcing agencies to sense illicit drugs, medical communities to remove overdosed medications from the human and animal body etc. Besides, drug delivery systems are theoretically being proposed for many years and experimentally found to deliver the drug to the targeted sites by reducing the harmful side effects significantly. In current COVID-19 pandemic, biosensors can play significant roles, e.g. to remove experimental drugs during the human trials if they show any unwanted adverse effect etc. where the drug delivery systems can be potentially applied to reduce the side effects. But before proceeding to these noble and expensive translational research works, advanced theoretical calculations can provide the possible outcomes with considerable accuracy. Hence in this review article, we have analyzed how theoretical calculations can be used to investigate LDNs as potential biosensor devices or drug delivery systems. We have also made a very brief discussion on the properties of biosensors or drug delivery systems which should be investigated for the biomedical applications and how to calculate them theoretically. Finally, we have made a detailed analysis of a large number of recently published research works where theoretical calculations were used to propose different LDNs for bio-sensing and drug delivery applications.

A theoretical study of allopurinol drug sensing by carbon and boron nitride nanostructures: DFT, QTAIM, RDG, NBO and PCM insights

The application of low-dimensional nanomaterials in clinical practice as efficient sensors has been increasing day by day due to progress in the field of nanoscience. In this research work, we have conducted a theoretical investigation to nominate a potential electrochemical sensor for the allopurinol (APN) drug molecule via studying the fundamental interactions of the drug molecule with two nanocages (carbon nanocage/CNC - C24 and boron nitride nanocage/BNNC - B12N12) and two nanosheets (graphene - C54H18 and boron nitride - B27N27H18) by means of the DFT B3LYP/6-31G(d,p) level of theory in both gas and water phases. The adsorption energies of APN-BNNC conjugated structures are in the range of -20.90 kcal mol-1 to -22.33 kcal mol-1, which indicates that weak chemisorption has occurred. This type of interaction happened due to charge transfer from the APN molecule to BNNC, which was validated and characterized based on the quantum theory of atoms in molecules, natural bond analysis, and reduced density gradient analysis. The highest decreases in energy gap (36.22% in gas and 26.79% in water) and maximum dipole moment (10.48 Debye in gas and 13.88 Debye in water) were perceived for the APN-BNNC conjugated structure, which was also verified via frontier molecular orbital (FMO) and MEP analysis. Also, the highest sensitivity (BNNC > BNNS > CNC > GNS) and favorable short recovery time (in the millisecond range) of BNNC can make it an efficient detector for the APN drug molecule.

The computational quantum mechanical investigation of the functionalized boron nitride nanocage as the smart carriers for favipiravir drug delivery: a DFT and QTAIM analysis

Favipiravir (FPV) is an antiviral drug used for the cure of Influenza virus, Ebola virus, Lassa virus etc. because it has excellent preventing ability of entry/exit of the virus into/from the human cells. Boron nitride nanocages have already drawn enormous attention as the delivery vehicle of various drug molecules for their nontoxicity and other lucrative properties. In this research, we have scrutinized the adsorption mechanism of FPV molecule on the exterior surface of pristine, Zn functionalized, and Ni functionalized B12N12 (BN, Zn f-BN, and Ni f-BN) nanocages by applying the DFT/QTAIM method and B3LYP/6-31G(d,p) approach. The adsorption energy (E_Ad) data reveal that the functionalized BN adsorbents can adsorb FPV drug very efficiently compared with the pristine adsorbent (Highest E_Ad is -56.40 kcal/mol for FPV adsorbed Ni f-BN complex). The reduction of the HOMO-LUMO gap up to 67.79% indicates that this drug can be detected by the produced electrical signal very promisingly in the case of f-BN nanocages. The topological parameters also validate the ability of the f-BN nanocages to adsorb the FPV molecule. The effect of the biological environment of our investigated structures has been studied by using water as a solvent, and spontaneous adsorption with high solubility is observed in our calculations. This analysis also reveals that f-BN nanocages can be a potential nanocarrier for the delivery of FPV drug molecule.Communicated by Ramaswamy H. Sarma.

Role of metal and anions in organo-metal halide perovskites CH3NH3MX3 (M: Cu, Zn, Ga, Ge, Sn, Pb; X: Cl, Br, I) on structural and optoelectronic properties for photovoltaic applications

Methylammonium metal halide perovskites have recently been explored for new uses due to their unique and exciting optoelectronic properties. Their exceptional electronic properties have often been attributed to the overlap between the metal cation s and halogen p states. In this study, density functional theory calculations have been carried out based on the orthorhombic phase of the organometal trihalide perovskite CH3NH3MX3 (M: Cu, Zn, Ga, Ge, Sn, Pb; X: Cl, Br, I) to systematically investigate the effects of the metal cation and halogen anion on the structural, electronic, and optical properties for solar cell applications. The calculated lattice parameters agree well with previously obtained experimental and theoretical results. All of these perovskites are direct band gap compounds at the G symmetry point, except CH3NH3GaX3. The band gap increases from iodide to chloride and also with the metal cation size, from Ge to Pb or Cu to Zn. Furthermore, metal halide perovskites show blue shifts in their optical absorption spectra with an increase in metal cation size. Among the studied examples, CH3NH3GaBr3 and CH3NH3CuCl3 absorb a wide range of light, from UV to the visible region, and possess very unusual high dielectric constants and refractive indices. Our calculations reveal that CH3NH3SnI3, CH3NH3GeI3, and CH3NH3ZnI3 are favorable candidates for lead-free photovoltaic applications.

Probing the surfaces of core-shell and hollow nanoparticles by solvent relaxation NMR

Measurement of the spin-spin NMR relaxation time (or its inverse, the rate) of water molecules in aqueous nanoparticle dispersions has become a popular approach to probe of the nature and structure of the particle surface and any adsorbed species. Here, we report on the characterisation of aqueous dispersions of hollow amorphous nanoparticles that have two liquid accessible surfaces (inner cavity surface and outer shell surface) plus the solid (silica) and core-shell (titania-silica) nanoparticle precursors from which the hollow particles have been prepared. In all cases, the observed water relaxation rates scale linearly with particle surface area, with the effect being more pronounced with increasing levels of titania present at the particle surface. Two distinct behaviours were observed for the hollow nanoparticles at very low volume fractions, which appear to merge with increasing surface area (particle concentration). Herewith, we further show the versatility of solvent NMR spectroscopy as a probe of surface character.

Functional endoscopic sinus surgery (FESS) for the Management of Chronic rhinosinusitis

Objective: To see the efficacy of surgery (FESS) and quality of life of the patient after Functional Endoscopic Sinus Surgery (FESS) for chronic rhinosinusiotis. Methods: It was a prospective type of study carried out Otolaryngology and Head-Neck Surgery Department of BIRDEM Hospital and Shaheed Suhrawardy Hospital, Dhaka from July 2009 to June 2010. Total 60 (sixty) patients were included in this study. Results: In this study, 22(36.67%) patients were operated for Ethmoidal polyp, 19(31.67%) for chronic rhinosinusitis, 9(15%) for Antrochoanal polyp, 6(10%) for Rhinosporidiosis and 4(6.67%) for Inverted papilloma. Per operative difficulties were gross DNS 07 (11.67%), unusual bleeding 6(10%), concha bullosa 5(8.33%). Post operative complications were periorbital echymoses (10%), Synechiae (1.67%), Epiphora (1.67%), infection(1.67%). Complete relief of symptoms were noted in 81.67% cases. Majority of patients 46(76.67%) were released from the hospital on 2nd post operative day. Conclusion: Instead of some limitations, outcome of functional endoscopic sinus surgery is rapidly flourishing, highly effective, less time consuming, less hospital stay & less expensive. Bangladesh J Otorhinolaryngol; October 2017; 23(2): 122-126

Interaction of Anagrelide drug molecule on pristine and doped boron nitride nanocages: a DFT, RDG, PCM and QTAIM investigation

Nowadays, a nanostructure-based drug delivery system is one of the most noticeable topics to be studied, and in this regard, boron nitride nanoclusters are promising drug carriers for targeted drug delivery systems. In this article, the interaction mechanism of Anagrelide (AG) drug with B12N12 and Al- and Ga-doped B12N12 nanocages have been investigated using DFT with B3LYP/6-31 G (d, p) method in both gas and water media. All our studied complexes are thermodynamically stable, and doped nanocage complexes have higher negative adsorption energy (EAd.) and negative solvation energy than AG/B12N12 complexes which correspond to the stability of these systems in both media. The negative highest EAd value is 64.98 kcal/mol (63.17 kcal/mol) and 65.69 kcal/mol (65.11 kcal/mol) in gas (water) media for complex F (AG/AlB11N12) and complex I (AG/GaB11N12) respectively, which refers to the highest stability of these systems. The enhanced values of dipole moment (from 12.40 (12.65) Debye to 17.21 (17.69) Debye in complex F (complex I)) also confirm their stability. The QTAIM and RDG analysis endorse the strong adsorption nature of the AG drug onto the AlB11N12, and GaB11N12 nanocages, which is consistent with the adsorption energy as chemisorption occurs for these complexes. According to the electronic properties, doped nanocages show high sensitivity that infers their promising nature for drug delivery purposes. Thus, complex F and complex I are promising drug delivery systems, and doped nanocages (AlB11N12 and GaB11N12) are better carriers than pristine nanocages for the AG drug delivery system.Communicated by Ramaswamy H. Sarma.

A DFT and QTAIM insight into ethylene oxide adsorption on the surfaces of pure and metal-decorated inorganic fullerene-like nanoclusters

In this industrial era, the use of low-dimensional nanomaterials as gas sensors for environmental monitoring has received enormous interest. To develop an effective sensing method for ethylene oxide (EO), DFT computations are conducted using method ωB97X-D and B3LYP with 6-31G(d,p) basis set to evaluate the adsorption behavior of ethylene oxide gas on the surfaces of pristine, as well as Scandium and Titanium decorated B12N12, Al12N12, and Al12P12 nanocages. Several properties like structural, physical, and electronic are studied methodically to better understand the sensing behavior. Scandium-decorated aluminum phosphate and boron nitride nanocages were shown to perform better in terms of adsorption properties. The short recovery time observed in this study is beneficial for the repetitive use of the gas sensor. The Natural Bond Orbital and molecular electrostatic potential analysis demonstrated a substantial quantity of charge transfer from adsorbate to adsorbents. The bandgap alternation after adsorption shows an influence of adsorption on electronic properties. The interactions of adsorbate and adsorbents are further studied using the ultraviolet-visible predicted spectrum, and quantum theory of atoms in molecules all of which yielded promising findings.

Numerical analysis of a single channel exposed core elliptical shaped PCF based highly sensitive SPR sensor for wide RI sensing

This study presents a numerical study of a highly sensitive photonic crystal fiber (PCF) surface plasmon resonance (SPR) sensor capable of detecting five types of cancer and bacterial contamination in water. By precisely arranging only two air holes in a single channel of an elliptical-shaped PCF, the sensor maximizes interaction between core-guided modes and surface plasmon polaritons (SPP) along the fiber. Evaluation using COMSOL Multiphysics simulation software, based on finite element method (FEM), demonstrates outstanding sensor performance across a wide refractive index (RI) range (1.33 to 1.43). With a maximum wavelength sensitivity (WS) of 188,000 nm/RIU and amplitude sensitivity (AS) of -22,377.99 RIU-1, the sensor achieveStructural Design and Methodologys a sensor resolution (SR) of 5.3191 × 10-7 RIU and figure of merit (FOM) of 854.55 RIU-1. Notably, it exhibits AS and WS values tailored for specific cancer cell types and water contamination. These results endorse the sensor's potential in diverse biological and molecular analyte RI detection applications within the visible to near-infrared (VNIR) range (0.55 to 4 µm), offering high sensitivity, affordability, wide sensing range, good linearity, low propagation loss, and simplicity in construction.

Triple drug therapy with quinine, cotrimoxazole and tetracycline in the management of cerebral malaria--A review of 254 cases

This study reflected that administration of tetracycline along with quinine and cotrimoxazole can reduce mortality from cerebral malaria significantly. In this five year prospective study in an endemic zone, the authors assessed the outcome of treatment with or without tetracycline among 254 cases of cerebral malaria. 100 patients were treated with quinine and cotrimoxazole and 154 patients were given triple therapy-quinine, cotrimoxazole and tetracycline. Fatality in group without tetracycline was 18%, whereas in the tetracycline group it was 12.33%. One interesting observation was that the parasite count was not proportional to the severity of disease. Out of 254 patients of this series, 136 patients (53.54%) had low parasite count (less than 1,000/cumm) and only 26 patients (10.23%) had infinity count. Quinine induced cardiac arrhythmia or hypoglycaemia was not seen in any patient.

Outcome of Myringoplasty in Underlay Technique

Background: Myringoplasty is one of the surgical techniques for the management of chronic supportive otitis media with permanent perforation of tympanic membrane. It is defined as simple surgical repair of tympanic membrane perforation without doing ossicular reconstruction. Objective: To determine the success rate of myringoplasty and to examine whether the hearing improvement is a potential indication for surgery. Methods: This study was conducted in the Department of Otorhinolaryngology and Head and Neck Surgery, Shaheed Suhrawardy Medical College Hospital from January 2017 to December 2017 and 100 patients who underwent myringoplasty in this period were analyzed. About 100 patients with dry central tympanic membrane perforations of various size were included in this study Results: Myringoplasty was performed in 100 patients. Male were (45%) and females were (55%).Twenty one (7%) of them belonged to age group of 10-20 years, 31 (31%) were in the age range of 21-33 years, 38(38%) were the age range 31-40 years while 24 (24%) aged between 41-50 years with mean age of 26.32 ±S.D 9.59 years. Overall success rate of graft uptake was noted in 88 (88%) out of 100 cases Conclusion: Myringoplasty is a safe surgical procedure in achieving intact tympanic membrane and to improve the hearing loss. Therefore, underlay technique being technically simple should be preferred, but the ultimate decision about the technique to be employed depends on the surgeons preference and the site of perforation  Bangladesh J of Otorhinolaryngology; October 2018; 24(2): 131-136