Recent advances in antimicrobial peptide-based therapy.

Antimicrobial peptides (AMPs) are a group of polypeptide chains that have the property to target and kill a myriad of microbial organisms including viruses, bacteria, protists, etc. The first discovered AMP was named gramicidin, an extract of aerobic soil bacteria. Further studies discovered that these peptides are present not only in prokaryotes but in eukaryotes as well. They play a vital role in human innate immunity and wound repair. Consequently, they have maintained a high level of intrigue among scientists in the field of immunology, especially so with the rise of antibiotic-resistant pathogens decreasing the reliability of antibiotics in healthcare. While AMPs have promising potential to substitute for common antibiotics, their use as effective replacements is barred by certain limitations. First, they have the potential to be cytotoxic to human cells. Second, they are unstable in the blood due to action by various proteolytic agents and ions that cause their degradation. This review provides an overview of the mechanism of AMPs, their limitations, and developments in recent years that provide techniques to overcome those limitations. We also discuss the advantages and drawbacks of AMPs as a replacement for antibiotics as compared to other alternatives such as synthetically modified bacteriophages, traditional medicine, and probiotics.

An insight into the state of nanotechnology-based electrochemical biosensors for PCOS detection.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders affecting many women of reproductive age all over the world. PCOS is associated with the onset of enduring health complications, notably diabetes and cardiovascular diseases. Furthermore, PCOS escalates the propensity for conditions such as obesity, insulin resistance, and dyslipidemia, which can potentially culminate in life-threatening scenarios. A pervasive predicament surrounding PCOS pertains to its underdiagnosis due to discrepancies in diagnostic criteria and the intricacy of available testing methodologies. Consequently, many women encounter substantial delays in diagnosis with traditional diagnostic approaches. Prompt identification is imperative, as any delay can precipitate severe consequences. The conventional techniques employed for PCOS detection typically suffer from suboptimal accuracy, protracted assay times, and inherent limitations, thereby constraining their widespread applicability and accessibility. In response to these challenges, various electrochemical methods leveraging nanotechnology have been documented. In this concise review, we endeavor to delineate the deficiencies associated with established conventional methodologies while accentuating the distinctive attributes and benefits inherent to contemporary biosensors. We place particular emphasis on elucidating the pivotal advancements and recent breakthroughs in the realm of nanotechnology-facilitated biosensors for the detection of PCOS.

Confronting antibiotic-resistant pathogens: Distinctive drug delivery potentials of progressive nanoparticles.

Antimicrobial resistance arises over time, usually due to genetic modifications. Global observations of high resistance rates to popular antibiotics used to treat common bacterial diseases, such as diarrhea, STIs, sepsis, and urinary tract infections, indicate that our supply of effective antibiotics is running low. The mechanisms of action of several antibiotic groups are covered in this review. Antimicrobials disrupt the development and metabolism of bacteria, leading to their eventual death. However, in recent years, microorganisms become resistant to the drugs. Bacteria encode resistant genes against antibiotics and inhibit the function of antibiotics by reducing the uptake of drugs, modifying the enzyme's active site, synthesizing enzymes to degrade antibiotics, and changing the structure of ribosomal subunits. Additionally, the methods of action of resistant bacteria against different kinds of antibiotics as well as their modes of action are discussed. Besides, the resistant pathogenic bacteria which get the most priority by World Health Organisation (WHO) for synthesizing new drugs, have also been incorporated. To overcome antimicrobial resistance, nanomaterials are used to increase the efficacy of antimicrobial drugs. Metallic, inorganic, and polymer-based nanoparticles once conjugated with antibacterial drugs, exhibit synergistic effects by increasing the efficacy of the drugs by inhibiting bacterial growth. Nanomaterial's toxic properties are proportional to their concentrations. Higher concentration nanomaterials are more toxic to the cells. In this review, the toxic properties of nanomaterials on lung cells, lymph nodes, and neuronal cells are also summarized.

Carbon Nanosheets Infused with Gold Nanoparticles as an Ultrasensitive Nose for Electrochemical Arsenic Sensing.

Herein, we introduce an eco-friendly electrochemical sensor based on melamine-enriched nitrogen-doped carbon nanosheets decorated with gold nanoparticles (Au-CNSm) for arsenic sensing. An extremely facile, low-toxicity, biocompatible, and affordable hydrothermal technique was adopted for the synthesis of the Au-CNSm nanocomposite. The Au-CNSm-integrated sensing platform was optimized for electrode composition by cyclic voltammetry (CV). Owing to the synergistic effects of melamine-enriched carbon nanosheets (CNSm) and gold nanoparticles (AuNPs), the anodic peak current increased in the Au-CNSm-modified sensing electrode as compared to the CNSm-decorated platform. A wide linear range of 0.0001-100 µM and a low detection limit of 0.0001 µM were obtained. The visual signals can be measured at a very minute concentration of 0.0001 µM (0.1 ppb) on a screen-printed carbon electrode (SPCE) modified with Au-CNSm. Hence, this electrode system clearly outperformed the previously reported studies in terms of linear range, limit of detection (LOD), and electrocatalytic activity for arsenic sensing. Interestingly, the fabricated biosensor can be developed as a point-of-care device for real-time environmental monitoring for public safety. Henceforth, owing to exceptional attributes such as portability, selectivity, and sensitivity, this device offers great promise in modeling a revolutionary new class of electrochemical sensing platforms for an ultrasensitive and reliable detection strategy for arsenite (As(III)).

Optimizing Glaucoma Care: A Holistic Approach.

How to cite this article: Dada T, Chauhan N. Optimizing Glaucoma Care: A Holistic Approach. J Curr Glaucoma Pract 2023;17(3):111-112.

Advancement in biomarker based effective diagnosis of neonatal sepsis.

Neonatal sepsis is considered as alarming medical emergency and becomes the common global reason of neonatal mortality. Non-specific symptoms and limitations of conventional diagnostic methods for neonatal sepsis mandate fast and reliable method to diagnose disease for point of care application. Recently, disease specific biomarkers have gained interest for rapid diagnosis that led to the development of electrochemical biosensor with enhanced specificity, sensitivity, cost-effectiveness and user-friendliness. Other than conventional biomarker C-reactive protein to diagnose neonatal sepsis, several potential biomarkers including Procalcitonin (PCT), Serum amyloid A (SAA) and other candidates are extensively investigated. The present review provides insights on advancements and diagnostic abilities of protein and nucleotide based biomarkers with their incorporation in developing electrochemical biosensors by employing novel fabrication strategies. This review provides an overview of most promising biomarker and its capability for neonatal sepsis diagnosis to fulfil future demand to develop electrochemical biosensor for point-of-care applications.

Advances in surface-enhanced Raman spectroscopy-based sensors for detection of various biomarkers.

Surface enhanced Raman spectroscopy (SERS) allows the ultrasensitive detection of analytes present in traces or even single molecule levels by the generation of electromagnetic fields. It is a powerful vibrational spectroscopic method that is capable to detect traces of chemical and biological analytes. SERS technique is involved in the extremely sophisticated studies of molecules with high specificity and sensitivity. In the vicinity of nanomaterials decorated surfaces, SERS can monitor extremely low concentrations of analytes in a non-destructive manner with narrow line widths. This review article is focused on some recently developed SERS-based sensors for distinct types of analytes like disease-related biomarkers, organic and inorganic molecules, various toxins, dyes, pesticides, bacteria as well as single molecules. This study aims to enlighten the arising sensing approaches based on the SERS technique. Apart from this, some basics of the SERS technique like their mechanism, detection strategy, and involvement of some specific nanomaterials are also highlighted herein. Finally, the study concluded with some discussion of applications of SERS in various fields like food and environmental analysis.

Development, standardization, and contextualization of qualitative tools for possible use in the assessment and valuation of snakebite envenomation.

Background: Snakebite envenoming, a neglected tropical disease (NTD), is an important public health problem that is responsible for more than 1 lakh deaths annually across the world. However, the majority of the data in this regard is from health institutions and data from community settings are scarce. The aim of the current study was to develop valid and reliable qualitative tools for assessing the burden of snakebites and the health-seeking behavior of the community. The tools developed thus will serve in creating a community connection and thereby strengthen primary care teams engaged in managing snakebites at the primary care level. Methods: A four-step design was used; (a) review of the available literature on the burden of disease, tools used to assess the burden, and the guidelines on snakebite (b) development, laying out, and contextualization of questions/items for the tools (c) pilot testing and establishment of validity. Results: A focus group discussion guide, key informant interview schedule for health professionals, community leaders, and traditional faith healers were matured for the implementation. Conclusion: A reliable and valid qualitative tool was developed to discern the speculations related to snakebites and its management in rural field settings.

Designing of a unique bioreceptor and fabrication of an efficient genosensing platform for neonatal sepsis detection.

We report the results of studies related to the fabrication of a nanostructured graphene oxide (GO)-based electrochemical genosensor for neonatal sepsis detection. Initially, we selected the fimA gene of E. coli for nenonatal sepsis detection and further designed a 20-mer long amine-terminated oligonucleotide. This designed oligonucleotide will work as a bioreceptor for the detection of the virulent fimA gene. An electrochemical genosensor was further developed where GO was used as an immobilization matrix. For the formation of a thin film of GO on an indium tin oxide (ITO)-coated glass electrode, an optimized DC potential of 10 V for 90 s was applied via an electrophoretic deposition unit. Thereafter, the designed oligonucleotides were immobilized through EDC-NHS chemistry. The nanomaterial and fabricated electrodes were characterized via X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and cyclic voltammetry techniques. The fabricated genosensor (BSA/pDNA/GO/ITO) has the ability to detect the target fimA gene with a linear detection range of 10-12 M to 10-6 M, a lower detection limit of 10-12 M and a sensitivity of 114.7 µA M-1 cm-2. We also investigated the biosensing ability of the developed genosensor in an artificial serum sample and the obtained electrochemical results were within the acceptable percentage relative standard deviation (% RSD), indicating that the fabricated genosensor can be used for the detection of neonatal sepsis by using a serum sample.

Rectus muscle pseudo-adherence syndrome.

Purpose: To describe a clinical entity called "rectus muscle pseudo-adherence syndrome" following buckling surgery. Methods: A retrospective data review was undertaken to analyze the clinical profile of strabismus patients who had developed it following buckling surgery. Between 2017 and 2021, a total of 14 patients were identified. The demography, surgical details, and intraoperative challenges were reviewed. Results: The average age of the 14 patients was 21.71 ± 5.23 years. The mean pre-op deviation was 42.35 ± 14.35 prism diopters (PD) of exotropia, and the mean post-op deviation was 8.25 ± 4.88 PD of residual exotropia at 26.16 ± 19.53 months follow-up. Intraoperatively, in the absence of a buckle, the thinned-out rectus adhered to the underlying sclera with much denser adhesions along its margins. When there was a buckle, the rectus muscle adhered to the outer surface of the buckle again, but less densely, with marginal union into the surrounding tenons. In both scenarios, due to the absence of protective muscle coverings, the rectus muscles were naturally adsorbed onto the immediately available surface in the presence of active healing by the tenons. Conclusion: While correcting ocular deviations following buckling surgery, a false sense of an absent, slipped, or thinned-out rectus muscle is very much possible. This is due to active healing of the muscle with the surrounding sclera or the buckle in a single layer of tenons. This is the rectus muscle pseudo-adherence syndrome, where the culprit is the healing process and not the muscle.

An ultrasensitive electrochemical DNA biosensor for monitoring Human papillomavirus-16 (HPV-16) using graphene oxide/Ag/Au nano-biohybrids.

A DNA-based electrochemical biosensor has been developed herein for the detection of Human papillomavirus-16 (HPV-16). HPV-16 is a double-stranded, non-enveloped, epitheliotropic DNA virus which responsible for cervical cancer. In this proposed biosensor, an indium tin oxide (ITO) coated glass electrode was modified for sensing HPV-16 using graphene oxide and silver coated gold nanoparticles. Subsequently, HPV-16 specific DNA probes were immobilized on a modified ITO surface. The synthesized nanocomposites were characterized by FE-SEM and UV-VIS spectroscopy techniques. Electrochemical characterization was performed by using cyclic voltammetry and electrochemical Impedance Spectroscopy methods. The hybridization between the probe and target DNA was analyzed by a reduction in current, mediated by methylene blue. The biosensor showed a qualitative inequity between the probe and target HPV-16 DNA. The developed biosensor showed high sensitivity as 0.54 mA/aM for the detection of HPV-16. In a linear range of 100 aM to 1 µM with 100 aM LOD, the proposed biosensor exhibited excellent performance with the rapid diagnosis. Thus, the results indicate that the developed HPV DNA biosensor shows good consistency with the present approaches and opens new opportunities for developing point-of-care devices. The diagnosis of HPV-16 infection in its early stage may also be possible with this detection system.

Detecting medication non-adherence in schizophrenia: A comparison of different methods among outpatients from a North Indian center.

Background: The rates of medication non-adherence among Indian patients with schizophrenia are high, and its detection poses problems. Comparisons of suitable measures to detect medication non-adherence in schizophrenia from Indian outpatient settings are scarce. Aim: This study compared simple and inexpensive methods of detecting medication non-adherence in schizophrenia among outpatients from a tertiary-care center in North India. Materials and Method: A longitudinal comparison of two self-reports, the Morisky Medication Adherence Questionnaire and the Drug Attitude Inventory-10, clinicians' ratings employing the Compliance Rating Scale, and clinic-based pill counts was conducted among 70 outpatients with schizophrenia. The rates and detection of medication non-adherence, associations with determinants of treatment non-adherence, and agreement between measures were examined at intake and after six months of follow-up (n = 53). Results: The self-reports had greater ability to detect medication adherence (specificity 41-65%; positive predictive values 25-51%; negative likelihood ratios 0.86-1.14) and moderate ability to detect medication non-adherence (sensitivity 27-65%; negative predictive values 49-69%; positive likelihood ratios 0.78-1.10). They yielded higher medication non-adherence rates, detected changes in medication non-adherence over time, and were associated with the other measures and the well-known correlates of medication non-adherence. Clinicians' ratings and pill counts had high sensitivity (56-90%) but low specificity (35-49%) to detect medication non-adherence. Conclusion: Self-reports are comparatively better screening options for detecting medication non-adherence among Indian outpatients with schizophrenia. However, the sequential use of different measures could lead to better recognition of medication non-adherence.

Fabrication of a Molecularly Imprinted Nano-Interface-Based Electrochemical Biosensor for the Detection of CagA Virulence Factors of H. pylori.

H. pylori is responsible for several stomach-related diseases including gastric cancer. The main virulence factor responsible for its establishment in human gastric cells is known as CagA. Therefore, in this study, we have fabricated a highly sensitive MIP-based electrochemical biosensor for the detection of CagA. For this, an rGO and gold-coated, screen-printed electrode sensing platform was designed to provide a surface for the immobilization of a CagA-specific, molecularly imprinted polymer; then it was characterized electrochemically. Interestingly, molecular dynamics simulations were studied to optimize the MIP prepolymerization system, resulting in a well-matched, optimized molar ratio within the experiment. A low binding energy upon template removal indicates the capability of MIP to recognize the CagA antigen through a strong binding affinity. Under the optimized electrochemical experimental conditions, the fabricated CagA-MIP/Au/rGO@SPE sensor exhibited high sensitivity (0.275 µA ng-1 mL-1) and a very low limit of detection (0.05 ng mL-1) in a linear range of 0.05-50 ng mL-1. The influence of other possible interferents in analytical response has also been observed with the successful determination of the CagA antigen.

Development and psychometric testing of the Knowledge, Attitude, and Practice Questionnaire to assess knowledge, attitude, and practices regarding COVID-19 among patients attending COVID screening outpatient department in a tertiary care hospital in North India.

Background: COVID-19 pandemic has hit the world leading to major disruptions globally. Due to its highly contagious nature and associated mortality, a wide array of emotional and behavioral reactions were seen which indirectly reflected the knowledge, attitudes, and practices (KAP) of individuals. Understanding the KAP of individuals is fundamental when it comes to decreasing future COVID cases. Aim: The study aimed to develop a Knowledge, Attitude, and Practice Questionnaire regarding COVID-19 (COVID-KAPQ) among patients attending screening outpatient department (OPD) in a tertiary care hospital in North India and evaluate its psychometric properties. Materials and Methods: The study procedure consisted of step-wise procedure starting with item generation, expert evaluation for categorization of items into domains of KAP and testing for psychometric properties. The items were generated and evaluated by the Delphi method based on 8 experts. Reliability and validity were assessed using data from 200 patients attending COVID screening OPD. Content validity was evaluated using content validity index (CVI); construct validity was examined using exploratory factor analysis and Cronbach's alpha coefficient was computed for internal consistency. Results: The final COVID-KAPQ consisted of three domains and 29 items. Cronbach's alpha coefficient for the entire questionnaire was 0.734, 0.710 for knowledge domain, 0.614 for attitudes domain, and 0.759 for practice domain. CVI ranged from 0.86 to 1. Five factors each for knowledge and attitudes domain and two factors for practice domain were extracted by principal factor analysis and varimax rotation, with a cumulative contribution of 70.19%, 71.54%, and 66.77% variance in KAP domain. Conclusions: A questionnaire COVID-KAPQ (KAP regarding COVID-19) was developed. Psychometric testing indicated that it had adequate validity and reliability for use in COVID research in the general population. This questionnaire might help the public health researchers to map the level of KAP in the population and plan awareness and prevention strategies accordingly.

Application of perovskites in bioimaging: the state-of-the-art and future developments.

BACKGROUND: Recently, the development of perovskite-based nanocrystals for sustainable applications in bioimaging and clinical diagnostics have become a very active area of research. From 2D hybrid to zero-dimensional quantum dots (QDs), perovskites along with a variety of characteristic features, specifically non-linear optoelectronics properties, have attracted enormous research attention. These characteristics can be tuned by the type of cations or anions and their ratio used in host perovskites. Carrier doping and chemical modifications are additional alternatives to control optical and magnetism in radiodiagnostics. AREA COVERED: This review begins by explaining the physical phenomena associated with luminescence or optical features of novel perovskites in diagnostic applications. Moreover, reported oxide, halide, doped, and QDs-based nanoprobes were elaborated. At last, the need for novel perovskite development, for example, persistent luminescent and low cytotoxicity is discussed, and the futuristic perspective of perovskites in clinical diagnostics with real-time demonstration is explained. EXPERT OPINION: Our article concludes that hybrid perovskites, including metal-free, core-shell nanocomposites-based, and alloy-based perovskites, exhibit tunable bandgap and high photoluminescence quantum yields which ultimately result in high optical features. However, given limited understanding of ion transport mechanisms and dependency on environmental conditions of the perovskites, more research is needed.

Tungsten Disulfide Decorated Screen-Printed Electrodes for Sensing of Glycated Hemoglobin.

Diabetes is a global menace, and its severity results in various disorders including cardiovascular, retinopathy, neuropathy, and nephropathy. Recently, diabetic conditions are diagnosed through the level of glycated hemoglobin. The level of glycated hemoglobin is determined with enzymatic methodology. Although the system is sensitive, it has various restrictions such as long processing times, expensive equipment required for testing, and complex steps involved in sample preparation. These limitations are a hindrance to faster results. The limitations of the developed methods can be eliminated through biosensors. In this work, an electrochemical platform was fabricated that facilitates the identification of glycated hemoglobin protein in diabetic patients. The working electrode on the integrated circuit was modified with molecularly imprinted polymer decorated with tungsten disulfide nanoparticles to enhance its analytical properties. The analytical properties of the biosensor were studied using electrochemical techniques. The obtained detection limit of the nanoelectronic sensor was 0.01 pM. The calculated sensitivity of the biosensor was observed to be 0.27 µA/pM. Also, the sensor promises to operate in a dynamic working concentration range and provide instant results.

Electrochemical Immunosensor for Detection of H. pylori Secretory Protein VacA on g-C3N4/ZnO Nanocomposite-Modified Au Electrode.

A g-C3N4/ZnO (graphitic carbon nitride/zinc oxide) nanocomposite-decorated gold electrode was employed to design an antigen-antibody-based electrochemical biosensor to detect Helicobacter pylori specific toxin, vacuolating cytotoxin A (VacA). The thermal condensation method was used to synthesize the g-C3N4/ZnO nanocomposite, and the nanocomposite was deposited electrochemically on a gold electrode. The morphology as well as the structure of the synthesized nanocomposite were confirmed by scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, and Fourier transform infrared techniques. The nanocomposite efficiently increased the sensor performance by amplifying the signals. EDC-NHS chemistry was exploited for attachment of VacA antibodies covalently with the g-C3N4/ZnO-modified gold electrode. This modified electrode was exploited for immunosensing of H. pylori-specific VacA antigen. The immunosensor was stable for up to 30 days and exhibited good sensitivity of 0.3 µA-1 ng mL-1 in a linear detection range of 0.1 to 12.8 ng mL-1. Apart from this, the fabricated sensor showed unprecedented reproducibility and remarkable selectivity toward the H. pylori toxin VacA. Thus, the highly sensitive immunosensor is a desirable platform for H. pylori detection in practical applications and clinical diagnosis.

Development of Nanomaterial-Modified Impedimetric Aptasensor-A Single-Step Strategy for 3,4-Methylenedioxymethylamphetamine Detection.

Developing rapid, sensitive detection methods for 3,4-Methylenedioxymethylamphetamine (MDMA) is crucial to reduce its current misuse in the world population. With that aim, we developed an aptamer-modified tin nanoparticle (SnNP)-based nanoarchitecture as an electrochemical sensor in this study. This platform exhibited a high electron transfer rate with enhanced conductivity arising from its large surface area in comparison to the bare electrode. This observation was explained by the 40-fold higher electroactive surface area of SnNPs@Au, which provided a large space for 1.0 µM AptMDMA (0.68 ± 0.36 × 1012 molecule/cm2) immobilization and yielded a significant electrochemical response in the presence of MDMA. Furthermore, the AptMDMA-modified SnNPs@Au sensing platform proved to be a simple yet ultrasensitive analytical device for MDMA detection in spiked biological and water samples. This novel electrochemical aptasensor showed good linearity in the range of 0.01-1.0 nM for MDMA (R2 = 0.97) with a limit of detection of 0.33 nM and a sensitivity of 0.54 ohm/nM. In addition, the device showed high accuracy and stability along with signal recoveries in the range of 92-96.7% (Relative Standard Deviation, RSD, 1.1-2.18%). In conclusion, the proposed aptasensor developed here is the first to combine SnNPs and aptamers for illicit compound detection, and it offers a reliable platform for recreational drug detection.