Structurally Dynamic Monocyte-Liposome Hybrid Vesicles as an Anticancer Drug Delivery Vehicle: A Crucial Correlation of Microscopic Elasticity and Ultrafast Dynamics.

A biomimetic cell-based carrier system based on monocyte membranes and liposomes has been designed to create a hybrid "Monocyte-LP" which inherits the surface antigens of the monocytes along with the drug encapsulation property of the liposome. Förster resonance energy transfer (FRET) and polarization gated anisotropy measurements show the stiffness of the vesicles obtained from monocyte membranes (Mons), phosphatidylcholine membranes (LP), and Monocyte-LP to follow an increasing order of Mons > Monocyte-LP > LP. The dynamics of interface bound water molecules plays a key role in the elasticity of the vesicles, which in turn imparts higher delivery efficacy to the hybrid Monocyte-LP for a model anticancer drug doxorubicin than the other two vesicles, indicating a critical balance between flexibility and rigidity for an efficient cellular uptake. The present work provides insight on the influence of elasticity of delivery vehicles for enhanced drug delivery.

A Mutagen Acts as a Potent Reducing Agent of Glycated Hemoglobin: a Combined Ultrafast Electron Transfer and Computational Studies.

Glycated hemoglobin (GHb) found in mammals undergoes irreversible damage when exposed to external redox agents, which is much more vulnerable than its normal counterpart hemoglobin (Hb). Besides the oxygen regulation throughout the body, Hb plays a vital role in balancing immunological health and the redox cycle. Photoinduced ultra-fast electron transfer phenomena actively participate in regulation of various kind of homeostasis involved in such biomacromolecules. In the present study we have shown that a well-known mutagen Ethidium Bromide (EtBr) reduces GHb in femtosecond time scale (efficiently) upon photoexcitation after efficient recognition in the biomolecule. We have performed similar experiment by colocalizing EtBr and Iron (Fe(III)) on the micellar surface as Hb mimic in order to study the excited state EtBr dynamics to rationalize the time scale obtained from EtBr in GHb and Hb. While other experimental techniques including Dynamic Light Scattering (DLS), Zeta potential, absorbance and emission spectroscopy have been employed for the confirmation of structural perturbation of GHb compared to Hb, a detailed computational studies involving molecular docking and density functional theory (DFT) have been employed for the explanation of the experimental observations.

Excited-State Dynamics of a Photoacid: A Potential Probe for Recognizing Transition from Lamellar to Nonlamellar Inverted Structures of Liposome based Nanocarriers.

Liposomes of a cationic lipid dioctadecyldimethylammonium bromide (DODAB) are efficient nanocarriers of nucleic acids. Incorporation of a neutral lipid monoolein (MO) in excess (xMO >0.5) changes the lamellar organization of DODAB liposomes into non-lamellar inverted structures of DODAB/MO liposomes facilitating nucleic acid delivery to cells. Photoexcitation of 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS), a photoacid, initiates an excited state proton transfer (ESPT) reaction in its protonated form (ROH*) generating the deprotonated anionic form (RO- *). The fluorescence intensity ratio (IROH* /IRO-* ) of these two forms is governed by the ESPT dynamics, and increases with increasing MO content (xMO ) in the cationic liposomes of DODAB. Transition from lamellar organization of DODAB liposomes into non-lamellar inverted structures of DODAB/MO liposomes, due to incorporation of MO (xMO ~0.7), is manifested by a significant increase of ESPT time (τPT ) and the time constant of wobbling motion (τW ) of HPTS. Thus, the lamellar organizations of DODAB or DODAB-rich (xMO 0.2) liposomes and the non-lamellar organizations of MO-rich (xMO ~0.7) liposomes are recognized by significantly different excited state dynamics of the photoacid.

Ultrafast spectroscopic studies on the interaction of reactive oxygen species with a probe impregnated in nanoscopic and microscopic matrix formulation.

Reactive oxygen species (ROS) plays important role to maintain homeostasis in living bodies. Here we have studied interaction of ROS generated from hydrogen peroxide (H2O2) with a well-known spectroscopic probe Rose Bengal (RB) encapsulated in nanoscopic sodium dodecyl sulphate (SDS) micelles in aqueous medium and entrapped in microscopic nylon 66 solid matrix generated using electrospinning technique. A detailed spectroscopic characterization of ROS with SDS encapsulated RB (RB-SDS) shows efficient interaction compared to that in bulk medium. The time resolved analysis on the probe based on femtosecond resolved 2D-spectrum time images collected from streak camera reveal the simultaneous existence of an ultrafast electron (∼6 ps) and a hole transfer mechanism (∼93 ps) resulting from generation of hydroxyl radicals through photobleaching of the probe in presence of H2O2. Based on the spectroscopic and time resolved studies of RB in bulk and in restricted (SDS) medium, we have further translated it for the development of an in-field prototype device which utilizes RB as a ROS sensor impregnated in a nylon thin film. The microscopic nylon solid matrix characterized by scanning electron microscope (SEM) shows porous structure for holding sample containing ROS. Our study quantitatively measures the amount of ROS by using RB embedded microfiber membrane. Thus, our developed prototype device based on RB embedded on the nylon matrix would be beneficial for the potential use in quantification of ROS in extracellular fluids and food materials.

A spectroscopy based prototype for the noninvasive detection of diabetes from human saliva using nanohybrids acting as nanozyme.

The recent prediction of diabetes to be a global pandemic invites a detection strategy preferably non-invasive, and bloodless to manage the disease and the associated complications. Here, we have synthesized chitosan polymer functionalized, organic-inorganic bio-compatible nano-hybrids of Mn3O4 nanoparticles, and characterized it by utilizing several optical methodologies for the structural characterization which shows the Michaelis Menten (MM) kinetics for glucose and alpha-amylase protein (well-known diabetes biomarkers). We have also studied the potentiality for the detection of alpha-amylase in human salivary secretion which is reported to be strongly correlated with uncontrolled hyperglycemia. Finally, we have developed a prototype for the measurement of glucose (LOD of 0.38 mg/dL, LOQ of 1.15 mg/dL) and HbA1c (LOD of 0.15% and LOQ of 0.45%) utilizing the basic knowledge in the study for the detection of uncontrolled hyperglycemia at the point-of-care. With the limited number of clinical trials, we have explored the potential of our work in combating the diabetic pandemic across the globe in near future.

Association of Blood Levels of Vitamin D and Its Binding Protein with Clinical Phenotypes of Multiple Sclerosis.

BACKGROUND: Low vitamin D levels may synergize with changing levels of the vitamin D binding protein (DBP) to precipitate in the development and clinical progression of multiple sclerosis (MS). In this study, this hypothesis was explored in groups of Kuwaiti healthy controls and patients with different clinical phenotypes of MS. METHODS: Fasting serum concentrations of 25-hydroxyvitamin D [25(OH)D] and DBP were measured in 146 healthy controls and 195 patients with MS. The latter were classified according to the duration, type, and onset of the disease and the mode of treatment. Factors such as relapse/remitting, and the use of nutritional supplements were also considered. RESULTS: The DBP levels were significantly lower in the patients than in the controls. This was more evident in newly diagnosed drug-naïve patients than in those patients with more established MS. MS status and severity were negatively impacted by concurrently low levels of 25(OH)D and DBP. This was most clearly expressed in drug-naïve patients and in those with a disease in relapse. It was also established that the 25(OH)D level had a significant positive correlation with the duration of the disease. CONCLUSION: Lower levels of 25(OH)D and DBP appear to have a synergistic effect on MS status. This was most clearly demonstrated in patients who were newly diagnosed (drug-naïve) and in those patients who were in relapse.

Unraveling an Ultrafast Electron Transport Mechanism in a Photocatalytic "Micromachine" for Their Potential Light Harvesting Applications.

Following the seminal discovery of Richard Feynman, several micromachines have been made that are capable of several applications, such as solar energy harvesting, remediation of environmental pollution, etc. Here we have synthesized a nanohybrid combining TiO2 nanoparticle and light harvesting robust organic molecule RK1 (2-cyano-3-(4-(7-(5-(4-(diphenylamino)phenyl)-4-octylthiophen-2-yl)benzo[c][1,2,5] thiadiazol-4-yl)phenyl) acrylic acid) as a model micromachine having solar light harvesting ability potential for application in photocatalysis, preparation of solar active devices, etc. Detailed structural characterization, including High Resolution Transmission Electronic Microscopy (HRTEM) and Fourier-transform infrared spectroscopy (FTIR), has been performed on the nanohybrid. We have studied the excited-state ultrafast dynamics of the efficient push-pull dye RK1 in solution, on mesoporous semiconductor nanoparticles, and in insulator nanoparticles by streak camera (resolution of the order of 500 fs). The dynamics of such photosensitizers in polar solvents have been reported, and it has been observed that completely different dynamics occur when they are attached to the surface of the semiconductor/insulator nanosurface. A femtosecond-resolved fast electron transfer has been reported when photosensitizer RK1 has been attached to the surface of the semiconductor nanoparticle, which in turn plays a crucial role in the development of an efficient light harvesting material. The generation of reactive oxygen species as a result of femtosecond-resolved photoinduced electron injection in the aqueous medium is also investigated in order to explore the possibility of redox-active micromachines, which are found to be crucial for efficient and enhanced photocatalysis.

The Impact of SARS-CoV-2 Infection in Unvaccinated Multiple Sclerosis Patients on Disease-Modifying Therapies.

OBJECTIVE: Disease-modifying therapies (DMTs) in multiple sclerosis (MS) may affect the course and outcome of COVID-19, but withholding them could permit disease activity. This study aimed to understand the course of COVID-19 in unvaccinated patients with MS on disease-modifying therapies. SUBJECTS AND METHODS: This descriptive study examined the course of COVID-19 among infected patients with MS followed up at a large tertiary center in Kuwait between March 1, 2020, and March 1, 2021. All subjects were outpatients at the time of data collection. RESULTS: We studied 51 patients with MS confirmed to be infected with SARS-CoV-2 using real-time polymerase chain reaction. Of these patients, 33/51 were female, median age was 35 years (IQR 27-39 years), median Expanded Disability Status Scale score was 1.5 (IQR zero-3), and 47/51 had RRMS. B-cell-depleting agents (ocrelizumab and rituximab) were given to 19 patients, another 19 were on immune cell traffickers (fingolimod and natalizumab), and 13 were on other DMT treatments (alemtuzumab, cladribine, interferon-beta, dimethyl fumarate, and teriflunomide). 43/51 of these patients experienced mild COVID-19, not requiring hospitalization. None of the subjects experienced MS relapses during infection. Two patients on rituximab had a moderate course of the illness, which required hospitalization for oxygen support, but did not need mechanical ventilation; the rest of the subjects remained asymptomatic. CONCLUSIONS: These findings suggest that DMT may not adversely affect the course of COVID-19 in MS patients; however, patients on B-cell-depleting agents trended toward a worse outcome.

Spectroscopic studies on a natural biomarker for the identification of origin and quality of tea extracts for the development of a portable and field deployable prototype.

Even in the era of smart technologies and IoT enabled devices, tea testing technique continues to be a person specific subjective task. In this study, we have employed optical spectroscopy-based detection technique for the quantitative validation of tea quality. In this regard, we have employed the external quantum yield of quercetin at 450 nm (λex = 360 nm), which is an enzymatic product generated by the activity of ß-glucosidase on rutin, a naturally occurring metabolite responsible for tea-flavour (quality). We have found that a specific point in a graph representing Optical Density and external Quantum Yield as independent and dependent variables respectively of an aqueous tea extract objectively indicates a specific variety of the tea. A variety of tea samples from various geographical origin have been analysed with the developed technique and found to be useful for the tea quality assessment. The principal component analysis distinctly showed the tea samples originated from Nepal and Darjeeling having similar external quantum yield, while the tea samples from Assam region had a lower external quantum yield. Furthermore, we have employed experimental and computational biology techniques for the detection of adulteration and health benefit of the tea extracts. In order to assure the portability/field use, we have also developed a prototype which confirms the results obtained in the laboratory. We are of the opinion that the simple user interface and almost zero maintenance cost of the device will make it useful and attractive with minimally trained manpower at low resource setting.

Antibacterial Properties and Computational Insights of Potent Novel Linezolid-Based Oxazolidinones.

The mounting evidence of bacterial resistance against commonly prescribed antibiotics warrants the development of new antibacterial drugs on an urgent basis. Linezolid, an oxazolidinone antibiotic, is a lead molecule in designing new oxazolidinones as antibacterial agents. In this study, we report the antibacterial potential of the novel oxazolidinone-sulphonamide/amide conjugates that were recently reported by our research group. The antibacterial assays showed that, from the series, oxazolidinones 2 and 3a exhibited excellent potency (MIC of 1.17 µg/mL) against B. subtilis and P. aeruginosa strains, along with good antibiofilm activity. Docking studies revealed higher binding affinities of oxazolidinones 2 and 3a compared to linezolid, which were further validated by molecular dynamics simulations. In addition to this, other computational studies, one-descriptor (log P) analysis, ADME-T and drug likeness studies demonstrated the potential of these novel linezolid-based oxazolidinones to be taken forward for further studies.

Sensing Bioavailable Water Content of Granulated Matrices: A Combined Experimental and Computational Study.

This paper represents the synthesis, characterization and validation of a cobalt chloride functionalised nano-porous cellulose membrane, a unique sensor for non-contact measurement of water potential in various biomedical and environmentally important matrices. The developed nano sensor, along with associated electronic components, is assembled as a prototype device called "MEGH" (Measuring Essential Good Hydration) to measure essential hydration of matrices of both environmental and biomedical importance, including soil and human skin. The relative humidity above the soil surface in equilibrium with the soil moisture has been studied for both hydrophobic and hydrophilic soil types. Our studies confirm that the percentage of water available to plants is greater in hydrophobic soil rather than in hydrophilic soil, which has also been corroborated using simulation studies. Furthermore, the requirement of hydration in human skin has also been evaluated by measuring the water potential of both dry and moist skin.

Non-invasive estimation of hemoglobin, bilirubin and oxygen saturation of neonates simultaneously using whole optical spectrum analysis at point of care.

The study was aimed to evaluate the performance of a newly developed spectroscopy-based non-invasive and noncontact device (SAMIRA) for the simultaneous measurement of hemoglobin, bilirubin and oxygen saturation as an alternative to the invasive biochemical method of blood sampling. The accuracy of the device was assessed in 4318 neonates having incidences of either anemia, jaundice, or hypoxia. Transcutaneous bilirubin, hemoglobin and blood saturation values were obtained by the newly developed instrument which was corroborated with the biochemical blood tests by expert clinicians. The instrument is trained using Artificial Neural Network Analysis to increase the acceptability of the data. The artificial intelligence incorporated within the instrument determines the disease condition of the neonate. The Pearson's correlation coefficient, r was found to be 0.987 for hemoglobin estimation and 0.988 for bilirubin and blood gas saturation respectively. The bias and the limits of agreement for the measurement of all the three parameters were within the clinically acceptance limit.

A novel molecular reporter for probing protein DNA recognition: An optical spectroscopic and molecular modeling study.

A novel benzo[a]phenoxazine-based fluorescent dye LV2 has been employed as a molecular reporter to probe recognition of a linker histone protein H1 by calf-thymus DNA (DNA). Fluorescence lifetime of LV2 buried in the globular domain of H1 (∼2.1 ns) or in the minor groove of DNA (∼0.93 ns) increases significantly to 2.65 ns upon interaction of the cationic protein with DNA indicating formation of the H1-DNA complex. The rotational relaxation time of the fluorophore buried in the globular domain of H1 increases significantly from 2.2 ns to 8.54 ns in the presence of DNA manifesting the recognition of H1 by DNA leading to formation of the H1-DNA complex. Molecular docking and molecular dynamics (MD) simulations have shown that binding of LV2 is energetically most favourable in the interface of the H1-DNA complex than in the globular domain of H1 or in the minor groove of DNA. As a consequence, orientational relaxation of the LV2 is significantly hindered in the protein-DNA interface compared to H1 or DNA giving rise to a much longer rotational relaxation time (8.54 ns) in the H1-DNA complex relative to that in pure H1 (2.2 ns) or DNA (5.7 ns). Thus, via a significant change of fluorescence lifetime and rotational relaxation time, the benzo[a]phenoxazine-based fluorescent dye buried within the globular domain of the cationic protein, or within the minor groove of DNA, reports on recognition of H1 by DNA.

A portable spectroscopic instrument for multiplexed monitoring of acute water toxicity: Design, testing, and evaluation.

The deteriorating water environment worldwide, mainly due to population explosion and uncontrolled direct disposal of harmful industrial and farming wastes, earnestly demands new approaches and accurate technologies to monitor water quality before consumption overcoming the shortcomings of the current methodologies. A spectroscopic water quality monitoring and early-warning instrument for evaluating acute water toxicity are the need of the hour. In this study, we have developed a prototype capable of the quantification of dissolved organic matter, dissolved chemicals, and suspended particulate matter in trace amounts dissolved in the water. The prototype estimates the water quality of the samples by measuring the absorbance, fluorescence, and scattering of the impurities simultaneously. The performance of the instrument was evaluated by detecting common water pollutants such as Benzopyrene, Crystal Violet, and Titanium di-oxide. The limit of detection values was found to be 0.50, 23.9, and 23.2 ppb (0.29 µM), respectively.

Molecular co-localization of multiple drugs in a nanoscopic delivery vehicle for potential synergistic remediation of multi-drug resistant bacteria.

Anti-microbial resistant infection is predicted to be alarming in upcoming years. In the present study, we proposed co-localization of two model drugs viz., rifampicin and benzothiazole used in anti-tuberculosis and anti-fungal agents respectively in a nanoscopic cationic micelle (cetyl triethyl ammonium bromide) with hydrodynamic diameter of 2.69 nm. Sterilization effect of the co-localized micellar formulation against a model multi-drug resistant bacterial strain viz., Methicillin resistant Staphylococcus aureus was also investigated. 99.88% decrease of bacterial growth in terms of colony forming unit was observed using the developed formulation. While Dynamic Light Scattering and Forsters Resonance Energy Transfer between benzothiazole and rifampicin show co-localization of the drugs in the nanoscopic micellar environment, analysis of time-resolved fluorescence decays by Infelta-Tachiya model and the probability distribution of the donor-acceptor distance fluctuations for 5 µM,10 µM and 15 µM acceptor concentrations confirm efficacy of the co-localization. Energy transfer efficiency and the donor acceptor distance are found to be 46% and 20.9 Å respectively. We have also used a detailed computational biology framework to rationalize the sterilization effect of our indigenous formulation. It has to be noted that the drugs used in our studies are not being used for their conventional indication. Rather the co-localization of the drugs in the micellar environment shows a completely different indication of their use in the remediation of multi-drug resistant bacteria revealing the re-purposing of the drugs for potential use in hospital-born multi-drug resistant bacterial infection.

"Seeing" invisible volatile organic compound (VOC) marker of urinary bladder cancer: A development from bench to bedside prototype spectroscopic device.

Urinary bladder cancer (UBC) is one of the most common cancers and has notoriously high risk of recurrence and mortality across the globe. Current clinical initial diagnostic approaches are either invasive or lacks sensitivity. In this study, an attempt has been made to invent a cost-effective, novel, portable diagnostic device based on the environmental sensitive fluorophores namely Nile Red (NR), Eosin Y (EY) and Rose Bengal (RB). They act as sensing agents for detecting volatile organic compounds (VOC) exclusively present in the urine sample of UBC patients and differentiate the UBC samples from the healthy control group. Upon exposure with a particular group of VOCs, a significant amount of increment in fluorescence intensities of NR, EY and RB were detected and recorded in our indigenously developed "NABIL" device. To check the performance of NABIL, the data collected from the device was compared with the conventional techniques by arranging a clinical trial with 21 healthy controls and 52 UBC patients. With the assistance of our analysis technique based on LabVIEW platform, very high sensitivity and accuracy from healthy controls have been achieved. For UBC patients, it shows impressive diagnostic results. In addition, depending on the sample processing mechanism, NABIL device can also reveal the grade of UBC and prognosis under treatment. Overall, this study contributes a novel, non-invasive, easy-to-use, inexpensive, real-time, accurate method for selectively UBC diagnosis, which can be useful for personalized care/diagnosis and postoperative surveillance, resulting in saving more lives.

Gastrointestinal mucormycosis in the pediatric age group: an evolving disease.

BACKGROUND: Mucormycosis is a devastating opportunistic fungal infection resulting in significant mortality, especially in pediatric patients with predisposing risk factors. MATERIALS & METHODS: Biopsies and surgical specimens reported and proven as Mucormycosis in children under 12 years of age were retrieved from the records for three years (January 2018 to January 2021). Complete data, predisposing factors, treatment, and clinical outcome were recorded. RESULTS: 15 cases were identified, ranging from 9 days to 5 years. The male-female ratio was 3:1; three children were preterm. Fourteen children were diagnosed with gastrointestinal Mucormycosis (14/15), and one had palatal and sinusoidal involvement. Abdominal pain with distention was the most typical complaint. On microscopy, biopsies and surgical specimens showed extensive liquefactive necrosis with broad aseptate fungal hyphae. An intraoperative diagnosis was rendered in two cases. All neonates underwent exploratory laparotomy with surgical debridement and were administered Liposomal Amphotericin B. However, only two neonates survived out of the fifteen cases, one with disease limited to the appendix and pouch colon. The others succumbed to the disease despite antifungal therapy and surgical debridement. Thus, the overall mortality in the current study was calculated to be 86%, with neonatal mortality of 75%. CONCLUSION: Gastrointestinal involvement is more common in neonates and infants with a male preponderance. The diagnosis relies on direct microscopy, histopathology, and fungal culture. Intraoperative tissue may be sent in all suspected cases for direct microscopic examination for rapid diagnosis and treatment.