Over 30-Fold Enhancement in DNA Translocation Dynamics through Nanoscale Pores Coated with an Anionic Surfactant.

Solid-state nanopores (ssNPs) are single-molecule sensors capable of label-free quantification of different biomolecules, which have become highly versatile with the introduction of different surface treatments. By modulating the surface charges of the ssNP, the electro-osmotic flow (EOF) can be controlled in turn affecting the in-pore hydrodynamic forces. Herein, we demonstrate that negative charge surfactant coating to ssNPs generates EOF that slows-down DNA translocation speed by >30-fold, without deterioration of the NP noise, hence significantly improving its performances. Consequently, surfactant-coated ssNPs can be used to reliably sense short DNA fragments at high voltage bias. To shed light on the EOF phenomena inside planar ssNPs, we introduce visualization of the electrically neutral fluorescent molecule's flow, hence decoupling the electrophoretic from EOF forces. Finite elements simulations are then used to show that EOF is likely responsible for in-pore drag and size-selective capture rate. This study broadens ssNPs use for multianalyte sensing in a single device.

Optimizing Gene Selection and Cancer Classification with Hybrid Sine Cosine and Cuckoo Search Algorithm.

Gene expression datasets offer a wide range of information about various biological processes. However, it is difficult to find the important genes among the high-dimensional biological data due to the existence of redundant and unimportant ones. Numerous Feature Selection (FS) techniques have been created to get beyond this obstacle. Improving the efficacy and precision of FS methodologies is crucial in order to identify significant genes amongst complicated complex biological data. In this work, we present a novel approach to gene selection called the Sine Cosine and Cuckoo Search Algorithm (SCACSA). This hybrid method is designed to work with well-known machine learning classifiers Support Vector Machine (SVM). Using a dataset on breast cancer, the hybrid gene selection algorithm's performance is carefully assessed and compared to other feature selection methods. To improve the quality of the feature set, we use minimum Redundancy Maximum Relevance (mRMR) as a filtering strategy in the first step. The hybrid SCACSA method is then used to enhance and optimize the gene selection procedure. Lastly, we classify the dataset according to the chosen genes by using the SVM classifier. Given the pivotal role gene selection plays in unraveling complex biological datasets, SCACSA stands out as an invaluable tool for the classification of cancer datasets. The findings help medical practitioners make well-informed decisions about cancer diagnosis and provide them with a valuable tool for navigating the complex world of gene expression data.

Magnetofluorescent Nanoprobe for Multimodal and Multicolor Bioimaging.

Although, superparamagnetic iron oxide nanoparticles (SPIONs) have extensively been used as a contrasting agent for magnetic resonance imaging (MRI), the lack of intrinsic fluorescence restricted their application as a multimodal probe, especially in combination with light microscopy. In Addition, the bigger size of the particle renders them incompetent for bioimaging of small organelles. Herein, we report, not only the synthesis of ultrasmall carbon containing magneto-fluorescent SPIONs with size ∼5 nm, but also demonstrate its capability as a multicolor imaging probe. Using MCF-7 and HeLa cell lines, we show that the SPIONs can provide high contrast mulicolor images of the cytoplasm from blue to red region. Further, single particle level photon count data revealed that the SPIONs could efficaciously be utilized in localization based super resolution microscopy in future.

Exploration of therapeutic role of montelukast and dexamethasone combination against paraquat induced inhalational toxicity.

OBJECTIVES: To explore the therapeutic role of a single dose combination of montelukast (MON) and dexamethasone (DXM) through intra-peritoneal route against paraquat (PQ)-intoxicated experimental Wistar rats. METHODS: In vivo the survival rate was investigated following the administration of both MON and DXM in PQ exposed rats. Lungs parameters including enhanced pause (Penh), tidal volume (TV) and breath per minute (BPM) were determined using the whole body plethysmograph (WBP). Further chest imaging and histopathological studies were conducted to evaluate the lungs injury. In vivo the antioxidant activity was carried out by determining the levels of catalase (SOD), superoxide dismutase (CAT) and glutathione peroxidase (GSH-Px). Lungs tissue concentration of different proinflammatory cytokines like IL-1ß, IL-6, TGF-ß1 and TNF-α was also determined. Finally, expression of NF-kB and p-NF-kB was investigated by western blot. RESULTS: Results of survival rate and levels of lungs parameters indicated therapeutic potential of combination treatment of MON and DXM. Protective activity on lungs was reflected in chest imaging and histopathological investigations. Moreover, combination treatment exhibited significant increased levels of all anti-oxidant parameters. Significant decrease in the levels of IL-1ß; IL-6; TGF-ß1 and TNF-α was also observed with the combination treatment of MON and DXM. Evidence of significant down regulation of NF-kB and phospho-NF-kB was also found with the combination treatment of MON and DXM. CONCLUSIONS: Given the advantage of therapeutic synergism activity of MON and DXM, it may be used in the prophylaxis of PQ-intoxication following clinical trials.

Determination of LCt50 of aerosolized paraquat and its pulmonary toxic implications in non-anesthetized rats.

Paraquat (PQ), a highly popular agricultural herbicide, is a serious occupational hazard with lethality reported at doses as low as 35 mg/kg body weight with intoxication occurring via inhalation or dermal route. The main objective of this study was to determine the median lethal concentration (LCt50) of paraquat through whole body exposure in adult male Wistar rats. Aerosolized PQ dissolved in water was delivered in a dose-dependent manner, to fully conscious rats confined in whole body plethysmograph (WBP), in a nebulized form with concentrations ranging from 40-200 mg/kg of air over a 4 h exposure period. Animals were observed up to 24-48 h post-exposure to observe any lethality. LCt50 estimates (±95% confidence interval) were obtained from the sequential stage-wise experiments using probit analysis. Rat lungs were examined radiologically and histopathologically. Gas chromatography-mass spectrometry (GC-MS) analysis determined the correlation of PQ accumulation in the lungs with the actual exposed dose of PQ. The actual LCt50 was found to be 218 g·min/m3 whereas 57.9 ± 2.90 µg/g of PQ accumulated in the lungs of each lifeless animal. All animals exhibited severe respiratory changes and pulmonary abnormalities. This study demonstrated that when compared with the actually exposed dose, the amount of PQ that accumulated in the lungs was very low, but enough to cause death in 50% of animal population and cause pulmonary abnormalities in each of the experimental animal. The PQ exposure carried out in WBP also facilitated the dermal absorption of aerosolized PQ, which replicated the real-life situation in workers operating with PQ.

Labelling Proteins with Carbon Nanodots.

We present efficient labelling of several proteins with orange-emissive carbon dots. N-Hydroxysuccinimide was used to activate the carboxyl groups of carbon dots, which subsequently reacted with the lysine groups present on the protein. Labelling was confirmed by UV absorption spectroscopy, PAGE and fluorescence correlation spectroscopy. Protein-conjugated carbon dots showed an enhancement in fluorescence lifetime and intensity owing to reduced intramolecular dynamic fluctuations. Single-molecule fluorescence measurements showed reduced fluorescence fluctuations and higher photon budget after protein tagging. Our study opens up opportunities to use carbon dots as highly precise biolabelling probes.

Time-Resolved Emission Reveals Ensemble of Emissive States as the Origin of Multicolor Fluorescence in Carbon Dots.

The origin of photoluminescence in carbon dots has baffled scientists since its discovery. We show that the photoluminescence spectra of carbon dots are inhomogeneously broadened due to the slower relaxation of the solvent molecules around it. This gives rise to excitation-dependent fluorescence that violates the Kasha-Vavilov rule. The time-resolved experiment shows significant energy redistribution, relaxation among the emitting states, and spectral migration of fluorescence spectra in the nanosecond time scale. The excitation-dependent multicolor emission in time-integrated spectra is typically governed by the relative population of these emitting states.

Full-Length Single Protein Molecules Tracking and Counting in Thin Silicon Channels.

Emerging single-molecule protein sensing techniques are ushering in a transformative era in biomedical research. Nevertheless, challenges persist in realizing ultra-fast full-length protein sensing, including loss of molecular integrity due to protein fragmentation, biases introduced by antibodies affinity, identification of proteoforms, and low throughputs. Here, a single-molecule method for parallel protein separation and tracking is introduced, yielding multi-dimensional molecular properties used for their identification. Proteins are tagged by chemo-selective dual amino-acid specific labels and are electrophoretically separated by their mass/charge in custom-designed thin silicon channel with subwavelength height. This approach allows analysis of thousands of individual proteins within a few minutes by tracking their motion during the migration. The power of the method is demonstrated by quantifying a cytokine panel for host-response discrimination between viral and bacterial infections. Moreover, it is shown that two clinically-relevant splice isoforms of Vascular endothelial growth factor (VEGF) can be accurately quantified from human serum samples. Being non-destructive and compatible with full-length intact proteins, this method opens up ways for antibody-free single-protein molecule quantification.

Performance analysis and comparison of Machine Learning and LoRa-based Healthcare model.

Diabetes Mellitus (DM) is a widespread condition that is one of the main causes of health disasters around the world, and health monitoring is one of the sustainable development topics. Currently, the Internet of Things (IoT) and Machine Learning (ML) technologies work together to provide a reliable method of monitoring and predicting Diabetes Mellitus. In this paper, we present the performance of a model for patient real-time data collection that employs the Hybrid Enhanced Adaptive Data Rate (HEADR) algorithm for the Long-Range (LoRa) protocol of the IoT. On the Contiki Cooja simulator, the LoRa protocol's performance is measured in terms of high dissemination and dynamic data transmission range allocation. Furthermore, by employing classification methods for the detection of diabetes severity levels on acquired data via the LoRa (HEADR) protocol, Machine Learning prediction takes place. For prediction, a variety of Machine Learning classifiers are employed, and the final results are compared with the already existing models where the Random Forest and Decision Tree classifiers outperform the others in terms of precision, recall, F-measure, and receiver operating curve (ROC) in the Python programming language. We also discovered that using k-fold cross-validation on k-neighbors, Logistic regression (LR), and Gaussian Nave Bayes (GNB) classifiers boosted the accuracy.

Carbapenem Antibiotics: Recent Update on Synthesis and Pharmacological Activities.

Right from the breakthrough of carbapenems since 1976, many schemes on synthesis, structure-activity relationship (SAR), and biological activities have been carried out, and several carbapenems have been developed, including parentally active carbapenems like imipenem, doripenem, biapenem, meropenem, ertapenem, panipenem, razupenem, tomopenem, and cilastatin, whereas orally active carbapenems like GV-118819, GV-104326, CS-834, L-084, DZ-2640, CL 191, 121, L-646, 591, S-4661, ER-35768, MK-826. Prodrugs of carbapenem with increased bioavailability include temopenem, tebipenem, sanfetrinem, LK-157, and CP 5484. Merck, Glaxo Welcome Research Group, Johnson & Johnson, Sankyo Group and Dai-ichi Group, and Wyeth-Ayerst Group were among the businesses that produced carbapenems. In this review Witting reaction, Mitsunobu reaction, Dieckmann reaction, palladium-catalyzed hydrogenolysis, E. coli-based cloned synthesis, as well as biosynthetic enzymes such as carbapenem synthetase (carA), carboxymethylproline synthase (carB), carbapenem synthase (carC) are included. Carbapenems are biologically mainly active in the infections like urinary tract infections, bloodstream infections, tuberculosis, intra-abdominal infections, and pathogens like anaerobes, gram-positive and gram-negative bacteria.

Preclinical assessment of nanostructured liquid crystalline particles for the management of bacterial keratitis: in vivo and pharmacokinetics study.

The research work was driven to develop, optimize, and characterize novel nanostructured liquid crystalline particles as carriers for the ocular delivery of vancomycin. The formulations were developed by fragmenting the cubic crystalline phase of glycerol monooleate, water, and poloxamer 407. A four-factor, three-level Taguchi statistical experimental design was constructed to optimize the formulation. Formulations exhibited internal-cubic structure of the vesicles with particle size in the range of 51.11 ± 0.96 nm to 158.73 ± 0.46 nm and negative zeta potential. Ex vivo transcorneal permeation studies demonstrated that the optimized cubosomes had a 2.4-fold increase in apparent permeability co-efficient as compared to vancomycin solution, whereas in vivo studies in rabbits demonstrated that the severity of keratitis was considerably lowered on day 3 with optimized cubosomes. Ocular pharmacokinetic studies evaluated the level of drug in aqueous humor, and results revealed that the time to peak concentration (Tmax) of vancomycin-loaded cubosomal formulation was about 1.9-fold higher and mean residence time was 2.2-fold greater than vancomycin solution. Furthermore, histological examination revealed that the corneal layers displayed well-maintained morphology without any stromal swelling, consequently indicating the safety of formulation. It could be concluded that the developed nanostructured liquid crystalline particles of vancomycin demonstrated improved pre-ocular residence time, increased permeability, reduced dosing frequency, controlled drug release, and reduced systemic side-effects. Results manifested that the developed vancomycin-loaded cubosomes could be a promising novel ocular carrier and an ideal substitute for conventional eye drops for the management of bacterial-keratitis.

Investigating nanostructured liquid crystalline particles as prospective ocular delivery vehicle for tobramycin sulfate: Ex vivo and in vivo studies.

Tobramycin remains the anchor drug for bacterial keratitis treatment and management; however, unlike other aminoglycosides, it does not pass through the gastrointestinal tract. The aim of the current investigation was to formulate tobramycin-loaded nanostructured liquid crystalline particles as an ophthalmic drug delivery system to ameliorate its preocular residence duration and ophthalmic bioavailability. Tobramycin cubosomes were fabricated by liquid-lipid monoolein, water, and poloxamer 407 as a stabilizer. Corneal penetration studies exhibited that the apparent permeation coefficient of tobramycin cubosomes was nearly 3.6-fold greater than marketed tobramycin eye drops. Ocular in vivo analysis performed in rabbits' eyes manifested that the intensity of bacterial keratitis was reduced on day 3, and on day 5, the manifestations were considerably mitigated with tobramycin cubosomes as compared to marked eye drops. Pharmacokinetic study of rabbit aqueous humor demonstrated that the area under curve and the peak concentration of optimized cubosomes were 3.1-fold and 3.3-fold, respectively, which was significantly higher than marketed eye drops. Moreover, histopathological studies illustrated the existence of normal ocular structures, thus indicating that there was no damage to the corneal epithelium or stromal layer. Consequently, the results acquired demonstrated that tobramycin-loaded cubosomal formulation could be a propitious lipid-based nanodelivery system that would enhance retention time and corneal permeability contrast to commercial eye drops.

Absorption and emission of light in red emissive carbon nanodots.

The structure-function relationship, especially the origin of absorption and emission of light in carbon nanodots (CNDs), has baffled scientists. The multilevel complexity arises due to the large number of by-products synthesized during the bottom-up approach. By performing systematic purification and characterization, we reveal the presence of a molecular fluorophore, quinoxalino[2,3-b]phenazine-2,3-diamine (QXPDA), in a large amount (∼80% of the total mass) in red emissive CNDs synthesized from o-phenylenediamine (OPDA), which is one of the well-known precursor molecules used for CND synthesis. The recorded NMR and mass spectra tentatively confirm the structure of QXPDA. The close resemblance of the experimental vibronic progression and the mirror symmetry of the absorption and emission spectra with the theoretically simulated spectra confirm an extended conjugated structure of QXPDA. Interestingly, QXPDA dictates the complete emission characteristics of the CNDs; in particular, it showed a striking similarity of its excitation independent emission spectra with that of the original synthesized red emissive CND solution. On the other hand, the CND like structure with a typical size of ∼4 nm was observed under a transmission electron microscope for a blue emissive species, which showed both excitation dependent and independent emission spectra. Interestingly, Raman spectroscopic data showed the similarity between QXPDA and the dot structure thus suggesting the formation of the QXPDA aggregated core structure in CNDs. We further demonstrated the parallelism in trends of absorption and emission of light from a few other red emissive CNDs, which were synthesized using different experimental conditions.

Intrinsically disordered proteins of viruses: Involvement in the mechanism of cell regulation and pathogenesis.

Intrinsically disordered proteins (IDPs) possess the property of inherent flexibility and can be distinguished from other proteins in terms of lack of any fixed structure. Such dynamic behavior of IDPs earned the name "Dancing Proteins." The exploration of these dancing proteins in viruses has just started and crucial details such as correlation of rapid evolution, high rate of mutation and accumulation of disordered contents in viral proteome at least understood partially. In order to gain a complete understanding of this correlation, there is a need to decipher the complexity of viral mediated cell hijacking and pathogenesis in the host organism. Further there is necessity to identify the specific patterns within viral and host IDPs such as aggregation; Molecular recognition features (MoRFs) and their association to virulence, host range and rate of evolution of viruses in order to tackle the viral-mediated diseases. The current book chapter summarizes the aforementioned details and suggests the novel opportunities for further research of IDPs senses in viruses.

Bovine Serum Albumin-Conjugated Red Emissive Gold Nanocluster as a Fluorescent Nanoprobe for Super-resolution Microscopy.

The gold nanocluster (GNC), because of its interesting photoluminescence properties and easy renal clearance from the body, has tremendous biomedical applications. Unfortunately, it has never been explored for super-resolution microscopy (SRM). Here, we present a protein-conjugated red emissive GNC for super-resolution radial fluctuation (SRRF) of the lysosome in HeLa cells. The diameter of the lysosome obtained in SRRF is ∼59 nm, which is very close to the original diameter of the smallest lysosome in HeLa cells. Conjugation of protein to GNC aided in the specific labeling of the lysosome. We hope that GNC not only will replace some of the common dyes used in SRM but due to its electron beam contrast could also be used as a multimodal probe for several other correlative bioimaging techniques.

Establishment and Escalation of an Amino Acid Stacked Repressible Release Embedded System Using Quality by Design.

OBJECTIVES: The traditional approach of developing a new delivery system is an exhaustive task and requires a number of resources like manpower, money, material, and time. To overcome this problem Quality by Design (QbD) can be utilized to obtain pharmaceutical products of desired (best) quality with minimum use of the above resources as well as determination of the impact of one factor over the desired associated process. The present research is focused on establishing a design for formulating optimized gelatin microspheres using QbD. MATERIALS AND METHODS: Repressible released embedded microspheres of L-arginine were prepared by performing cross linking of gelatin using glutaraldehyde. Characterization of the formulated embedded microspheres was done based on infrared spectroscopy, scanning electron microscopy, percentage yield, microsphere size, drug entrapment efficiency, and drug release. The impact of concentrations of gelatin and ethyl cellulose was determined over dependent response like percentage yield, microsphere size, and drug entrapment efficiency. RESULTS: A response surface curve was obtained using a 32 central composite design and the optimized batch was obtained with percentage yield, microsphere size, and drug entrapment efficiency of 89.98, 333.32 mm, and 82.61%, respectively. Validation of the optimized batch was done by formulating four different batches with optimized values of independent response and a comparison of the observed responses with the predicted ones was set up and all these batches were found close to the predicted values and show the validity of the optimized data. CONCLUSION: The QbD approach is quite efficient to get optimized drug delivery systems of L-arginine without exhaustive study.

Dual responsive specifically labelled carbogenic fluorescent nanodots for super resolution and electron microscopy.

Due to their high biocompatibility and nontoxic nature, carbogenic fluorescent nanodots (FNDs) have already shown their application in bioimaging. However, their non-specific labeling has restricted their application in live cell super resolution microscopy (SRM). Here we introduce, for the first time, an orange emissive FND, specifically conjugated to the HeLa cell actin filament, for successful single molecule stochastic optical reconstruction microscopy (STORM) and super resolution radial fluctuation (SRRF) microscopy. The resolution obtained in SRRF (∼35 nm) was almost an order of magnitude less than the diffraction limited spot. Interestingly, in addition, the FND also showed electron microscope (EM) contrast inside the cell. We hope that this FND will not only replace some of the common dyes used for SRM, but will also be used as a dual responsive marker in correlative super resolution microscopy (CLEM).

Carbon coated core-shell multifunctional fluorescent SPIONs.

Due to their unique magnetic properties, multiple surface functionality and biocompatibility, superparamagnetic iron oxide nanoparticles (SPIONs) show very promising characteristics as magnetic resonance (MR) contrast agents in biomedical applications. However, a lack of fluorescence makes SPIONs inappropriate for multimodal bioimaging. SPIONs surface functionalized by either organic fluorescent molecules or semiconductor quantum dots (QDs) have been reported as bioimaging probes but subsequent deterioration of the fluorescent dyes due to low photostability and quick photobleaching limits their long term practical application. In addition, QDs are found to be toxic in nature. Here, we present a novel one step method to synthesize non-toxic carbon coated highly photostable core-shell magnetic and fluorescent SPIONs with long-lasting fluorescence alongside a superior magnetic resonance (MR) imaging ability. Apart from the highly comparable superparamagnetic properties of the SPIONs, the optical response of the material is much better than commonly used Rhodamine or cyanine dyes.

An Overview on Bacteriophages: A Natural Nanostructured Antibacterial Agent.

BACKGROUND: Recent advances in the field of bionanomedicine not only enable us to produce biomaterials but also to manipulate them at molecular level. Viruses particularly bacteriophages are a promising nanomaterial that can be functionalized with great precision. Bacteriophages are the natural antimicrobial agents that fight against antibiotic resistant bacteria which cause infections in animals, humans, or in crops of agricultural value. The idea of utilizing bacteriophages as therapeutic agents is due to their ability to kill bacteria at the end of the infectious cycle. OBJECTIVE: This paper reviewed the general biology of bacteriophages and the presence of receptors on the bacteria which are necessary for the recognition and adsorption of bacteriophages. Pharmacokinetics and therapeutic potential of bacteriophages administered through various routes in treating diverse bacterial infections is also reviewed along with the problems associated with bacteriophage therapy. CONCLUSION: Among various routes of administration, parenteral route is found to be the most thriving route for the treatment of systemic infections whereas oral route is meant to treat gastrointestinal infections and; local delivery (skin, nasal, ears) of phages has proven its potency to treat topical infections.

Phase engineering of seamless heterophase homojunctions with co-existing 3R and 2H phases in WS2 monolayers.

Self-organized semiconductor-semiconductor heterostructures (3R-2H) that coexist in atomically thin 2D monolayers forming homojunctions are of great importance for next-generation nanoelectronics and optoelectronics applications. Herein, we investigated the defect controlled growth of heterogeneous electronic structure within a single domain of monolayer WS2 to enable in-plane homojunctions consisting of alternate 2H semiconducting and 3R semiconducting phases of WS2. X-ray photoelectron, Raman, and photoluminescence spectroscopy along with fluorescence and Kelvin probe force microscopy imaging confirm the formation of homojunctions, enabling a direct correlation between chemical heterogeneity and electronic heterostructure in the atomically thin WS2 monolayer. Quantitative analysis of phase fractions shows 59% stable 2H phase and 41% metastable 3R phase estimated over WS2 flakes of different sizes. Time-resolved fluorescence lifetime imaging confirms distinct contrast between 2H and 3R phases with two distinct lifetimes of 3.2 ns and 1.1 ns, respectively. Kelvin probe force microscopy imaging revealed an abrupt change in the contact potential difference with a depletion width of ∼2.5 µm, capturing a difference in work function of ∼40 meV across the homojunction. Further, the thermal stability of coexisting phases and their temperature dependent optical behavior show a distinct difference among 2H and 3R phases. The investigated aspects of the controlled in plane growth of coexisting phases with seamless homojunctions, their properties, and their thermal stability will enable the development of nanoscale devices that are free from issues of lattice mismatch and grain boundaries.