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.

Chemoprevention of bilirubin encephalopathy with a nanoceutical agent.

BACKGROUND: Targeted rapid degradation of bilirubin has the potential to thwart incipient bilirubin encephalopathy. We investigated a novel spinel-structured citrate-functionalized trimanganese tetroxide nanoparticle (C-Mn3O4 NP, the nanodrug) to degrade both systemic and neural bilirubin loads. METHOD: Severe neonatal unconjugated hyperbilirubinemia (SNH) was induced in neonatal C57BL/6j mice model with phenylhydrazine (PHz) intoxication. Efficiency of the nanodrug on both in vivo bilirubin degradation and amelioration of bilirubin encephalopathy and associated neurobehavioral sequelae were evaluated. RESULTS: Single oral dose (0.25 mg kg-1 bodyweight) of the nanodrug reduced both total serum bilirubin (TSB) and unconjugated bilirubin (UCB) in SNH rodents. Significant (p < 0.0001) UCB and TSB-degradation rates were reported within 4-8 h at 1.84 ± 0.26 and 2.19 ± 0.31 mg dL-1 h-1, respectively. Neural bilirubin load was decreased by 5.6 nmol g-1 (p = 0.0002) along with improved measures of neurobehavior, neuromotor movements, learning, and memory. Histopathological studies confirm that the nanodrug prevented neural cell reduction in Purkinje and substantia nigra regions, eosinophilic neurons, spongiosis, and cell shrinkage in SNH brain parenchyma. Brain oxidative status was maintained in nanodrug-treated SNH cohort. Pharmacokinetic data corroborated the bilirubin degradation rate with plasma nanodrug concentrations. CONCLUSION: This study demonstrates the in vivo capacity of this novel nanodrug to reduce systemic and neural bilirubin load and reverse bilirubin-induced neurotoxicity. Further compilation of a drug-safety-dossier is warranted to translate this novel therapeutic chemopreventive approach to clinical settings. IMPACT: None of the current pharmacotherapeutics treat severe neonatal hyperbilirubinemia (SNH) to prevent risks of neurotoxicity. In this preclinical study, a newly investigated nano-formulation, citrate-functionalized Mn3O4 nanoparticles (C-Mn3O4 NPs), exhibits bilirubin reduction properties in rodents. Chemopreventive properties of this nano-formulation demonstrate an efficacious, efficient agent that appears to be safe in these early studies. Translation of C-Mn3O4 NPs to prospective preclinical and clinical trials in appropriate in vivo models should be explored as a potential novel pharmacotherapy for SNH.

Host-Assisted Delivery of a Model Drug to Genomic DNA: Key Information from Ultrafast Spectroscopy and in silico Study.

Drug delivery to a target without adverse effects is one of the major criteria for clinical use. Herein, we have made an attempt to explore the delivery efficacy of SDS surfactant in a monomer and micellar stage during the delivery of the model drug, Toluidine Blue (TB) from the micellar cavity to DNA. Molecular recognition of pre-micellar SDS encapsulated TB with DNA occurs at a rate constant of k1 ∼652 s-1 . However, no significant release of encapsulated TB at micellar concentration was observed within the experimental time frame. This originated from the higher binding affinity of TB towards the nano-cavity of SDS at micellar concentration which does not allow the delivery of TB from the nano-cavity of SDS micelles to DNA. Thus, molecular recognition controls the extent of DNA recognition by TB which in turn modulates the rate of delivery of TB from SDS in a concentration-dependent manner.

All-in-One: Sensing, Adsorptive Removal, and Photocatalytic Degradation of Nitro-Explosive Contaminants by Microporous Polycarbazole Polymer.

A highly multitasking 3D polycarbazole based microporous organic polymer (ACzMOP) is rationally prepared via a low-cost FeCl3 catalyzed polymerization route utilizing a newly developed Td -symmetric adamantane core tetracarbazolic monomer. The nitrogen-rich ACzMOP integrated with photo-redox active electron-rich π-conjugated polycarbazole modules featuring large BET surface area of 1568 m 2  g -1 , pore volume of 1.58 cc g -1 , excellent physicochemical stability, and strong fluorescence in both aqueous and solid phases. Aqueous suspension including ACzMOP coated paper strip is highly responsive to the aqueous solution of nitroaromatics especially 2,4-dinitrotoluene, an unavoidable intermediate of 2,4,6-trinitrotoluene contamination, with ultra-trace level detection capability (up to 0.32 ppb). The thin layer of solid polymer is capable of detecting nitroaromatic vapors, especially nitrotoluenes in a very sensitive manner. Moreover, the polymer exhibit record uptake of nitrotoluenes and nitrophenols with maximum uptake capability up to 510 mg g -1  setting a new benchmark among known porous materials. The polymer efficiently degrades toxic 4-nitrophenol to the value-added 4-aminophenol precursor (TOF = 0.143 h -1 ) via photocatalytic pathway. For the very first time, ACzMOP as a single material system is capable of efficiently sensing and removing all sorts of nitroaromatic contaminations with regenerability under mild washing/vacuum conditions.

Flexibility modulates the catalytic activity of a thermostable enzyme: key information from optical spectroscopy and molecular dynamics simulation.

Enzymes are dynamical macromolecules and their conformation can be altered via local fluctuations of side chains, large scale loop and even domain motions which are intimately linked to their function. Herein, we have addressed the role of dynamic flexibility in the catalytic activity of a thermostable enzyme almond beta-glucosidase (BGL). Optical spectroscopy and classical molecular dynamics (MD) simulation were employed to study the thermal stability, catalytic activity and dynamical flexibility of the enzyme. An enzyme assay reveals high thermal stability and optimum catalytic activity at 333 K. Polarization-gated fluorescence anisotropy measurements employing 8-anilino-1-napthelenesulfonic acid (ANS) have indicated increasing flexibility of the enzyme with an increase in temperature. A study of the atomic 3D structure of the enzyme shows the presence of four loop regions (LRs) strategically placed over the catalytic barrel as a lid. MD simulations have indicated that the flexibility of BGL increases concurrently with temperature through different fluctuating characteristics of the enzyme's LRs. Principal Component Analysis (PCA) and the Steered Molecular Dynamics (SMD) simulation manifest the gatekeeper role of the four LRs through their dynamic fluctuations surrounding the active site which controls the catalytic activity of BGL.

Targeted Redox Balancing through Pulmonary Nanomedicine Delivery Reverses Oxidative Stress Induced Lung Inflammation.

Non-invasive delivery of drugs is important for the reversal of respiratory diseases essentially by-passing metabolic pathways and targeting large surface area of drug absorption. Here, we study the inhalation of a redox nano medicine namely citrate functionalized Mn3O4 (C-Mn3O4) duly encapsulated in droplet evaporated aerosols for the balancing of oxidative stress generated by the exposure of Chromium (VI) ion, a potential lung carcinogenic agent. Our optical spectroscopic in-vitro experiments demonstrates the efficacy of redox balancing of the encapsulated nanoparticles (NP) for the maintenance of a homeostatic condition. The formation of Cr-NP complex as an excretion of the heavy metal is also demonstrated through optical spectroscopic and high resolution transmission optical microscopy (HRTEM). Our studies confirm the oxidative stress mitigation activity of the Cr-NP complex. A detailed immunological assay followed by histopathological studies and assessment of mitochondrial parameters in pre-clinical mice model with chromium (Cr) induced lung inflammation establishes the mechanism of drug action to be redox-buffering. Thus, localised delivery of C-Mn3O4 NPs in the respiratory tract via aerosols can act as an effective nanotherapeutic agent against oxidative stress induced lung inflammation.

A study of scarless wound healing through programmed inflammation, proliferation and maturation using a redox balancing nanogel.

In the study, we have shown the efficacy of an indigenously developed redox balancing chitosan gel with impregnated citrate capped Mn3O4 nanoparticles (nanogel). Application of the nanogel on a wound of preclinical mice model shows role of various signaling molecules and growth factors, and involvement of reactive oxygen species (ROS) at every stage, namely hemostasis, inflammation, and proliferation leading to complete maturation for the scarless wound healing. While in vitro characterization of nanogel using SEM, EDAX, and optical spectroscopy reveals pH regulated redox buffering capacity, in vivo preclinical studies on Swiss albino involving IL-12, IFN-γ, and α-SMA signaling molecules and detailed histopathological investigation and angiogenesis on every stage elucidate role of redox buffering for the complete wound healing process.

Chitosan functionalized Mn3O4 nanoparticles counteracts ulcerative colitis in mice through modulation of cellular redox state.

Recent findings suggest a key role for reactive oxygen species (ROS) in the pathogenesis and progression of ulcerative colitis (UC). Several studies have also highlighted the efficacy of citrate functionalized Mn3O4 nanoparticles as redox medicine against a number of ROS-mediated disorders. Here we show that synthesized nanoparticles consisting of chitosan functionalized tri-manganese tetroxide (Mn3O4) can restore redox balance in a mouse model of UC induced by dextran sulfate sodium (DSS). Our in-vitro characterization of the developed nanoparticle confirms critical electronic transitions in the nanoparticle to be important for the redox buffering activity in the animal model. A careful administration of the developed nanoparticle not only reduces inflammatory markers in the animals, but also reduces the mortality rate from the induced disease. This study provides a proof of concept for the use of nanomaterial with synergistic anti-inflammatory and redox buffering capacity to prevent and treat ulcerative colitis.

A nano erythropoiesis stimulating agent for the treatment of anemia and associated disorders.

The usual treatment for anemia and especially for anemia of inflammation (also called anemia of chronic disease) is supportive care with the target of improving the lifestyle of the patients. There is no effective medication to date for proper management. As the inflammation, erythropoiesis, and oxidative stress are the major concerns in this case, it inspired us to use a nano-erythropoietin stimulating agent (nano-ESA) made up of a nano-complex of manganese and citrate (Mn-citrate nano-complex), which has been hypothesized to have excellent antioxidant and anti-inflammatory mechanisms. Single oral dose of the nano-ESA efficiently prevented the onset of anemia as well as led to recovery from anemia in our phenylhydrazine (PHz)-intoxicated C57BL/6J mice model of anemia without any toxicological side effects. These preliminary findings may pave the way for an affordable and safe clinical use of the nano-ESA as a rapid recovery medication of anemia, especially anemia of inflammation.

Chlorinative Cyclization of Aryl Alkynoates Using NCS and 9-Mesityl-10-methylacridinium Perchlorate Photocatalyst.

In a chlorinative cyclization, Mes-Acr-MeClO4 acted as a visible-light photocatalyst to obtain 3-chlorocoumarins from aryl alkynoates and N-chlorosuccinimide (NCS). The radical initiated reaction proceeded in a cascading manner via Cl- addition to alkynoates. Next, 5-exo-trig spirocyclization and subsequent 1,2-ester migration led to the formation of C-C and C-Cl bonds.

Lowest aqueous picomolar fluoride ions and in vivo aluminum toxicity detection by an aluminum(iii) binding chemosensor.

Aluminum toxicity in biological systems is a well-known issue yet remains as a prevalent and unsolvable problem due to the lack of proper molecular tools that can detect free aluminum(iii) or Al(iii) ions in vivo. Herein, we report a water-soluble photo-induced electron transfer (PET)-based turn-ON/OFF fluorometric chemosensor for the dual detection of Al(iii) and fluoride ions in aqueous media with a nanomolar (∼1.7 × 10-9 M) and picomolar (∼2 × 10-12 M, lowest ever detection so far) detection limit, respectively. Fluoride ions in sea water could be detected as well as the recognition of non-contamination in drinking water. In addition, using live-cell microscopy, Al(iii) ions were detected in live biological samples in vivo to aid establishing the aluminum-toxicity effect.

Redox Buffering Capacity of Nanomaterials as an Index of ROS-Based Therapeutics and Toxicity: A Preclinical Animal Study.

Precise control of intracellular redox status, i.e., maintenance of the physiological level of reactive oxygen species (ROS) for mediating normal cellular functions (oxidative eustress) while evading the excess ROS stress (distress), is central to the concept of redox medicine. In this regard, engineered nanoparticles with unique ROS generation, transition, and depletion functions have the potential to be the choice of redox therapeutics. However, it is always challenging to estimate whether ROS-induced intracellular events are beneficial or deleterious to the cell. Here, we propose the concept of redox buffering capacity as a therapeutic index of engineered nanomaterials. As a steady redox state is maintained for normal functioning cells, we hypothesize that the ability of a nanomaterial to preserve this homeostatic condition will dictate its therapeutic efficacy. Additionally, the redox buffering capacity is expected to provide information about the nanoparticle toxicity. Here, using citrate-functionalized trimanganese tetroxide nanoparticles (C-Mn3O4 NPs) as a model nanosystem, we explored its redox buffering capacity in erythrocytes. Furthermore, we went on to study the chronic toxic effect (if any) of this nanomaterial in the animal model to co-relate with the experimentally estimated redox buffering capacity. This study could function as a framework for assessing the capability of a nanomaterial as redox medicine (whether maintains eustress or damages by creating distress), thus orienting its application and safety for clinical use.

Redox nanomedicine ameliorates chronic kidney disease (CKD) by mitochondrial reconditioning in mice.

Targeting reactive oxygen species (ROS) while maintaining cellular redox signaling is crucial in the development of redox medicine as the origin of several prevailing diseases including chronic kidney disease (CKD) is linked to ROS imbalance and associated mitochondrial dysfunction. Here, we have shown that a potential nanomedicine comprising of Mn3O4 nanoparticles duly functionalized with biocompatible ligand citrate (C-Mn3O4 NPs) can maintain cellular redox balance in an animal model of oxidative injury. We developed a cisplatin-induced CKD model in C57BL/6j mice with severe mitochondrial dysfunction and oxidative distress leading to the pathogenesis. Four weeks of treatment with C-Mn3O4 NPs restored renal function, preserved normal kidney architecture, ameliorated overexpression of pro-inflammatory cytokines, and arrested glomerulosclerosis and interstitial fibrosis. A detailed study involving human embryonic kidney (HEK 293) cells and isolated mitochondria from experimental animals revealed that the molecular mechanism behind the pharmacological action of the nanomedicine involves protection of structural and functional integrity of mitochondria from oxidative damage, subsequent reduction in intracellular ROS, and maintenance of cellular redox homeostasis. To the best of our knowledge, such studies that efficiently treated a multifaceted disease like CKD using a biocompatible redox nanomedicine are sparse in the literature. Successful clinical translation of this nanomedicine may open a new avenue in redox-mediated therapeutics of several other diseases (e.g., diabetic nephropathy, neurodegeneration, and cardiovascular disease) where oxidative distress plays a central role in pathogenesis.

Incorporation of a Biocompatible Nanozyme in Cellular Antioxidant Enzyme Cascade Reverses Huntington's Like Disorder in Preclinical Model.

The potentiality of nano-enzymes in therapeutic use has directed contemporary research to develop a substitute for natural enzymes, which are suffering from several disadvantages including low stability, high cost, and difficulty in storage. However, inherent toxicity, inefficiency in the physiological milieu, and incompatibility to function in cellular enzyme networks limit the therapeutic use of nanozymes in living systems. Here, it is shown that citrate functionalized manganese-based biocompatible nanoscale material (C-Mn3 O4 NP) efficiently mimics glutathione peroxidase (GPx) enzyme in the physiological milieu and easily incorporates into the cellular multienzyme cascade for H2 O2 scavenging. A detailed computational study reveals the mechanism of the nanozyme action. The in vivo therapeutic efficacy of C-Mn3 O4 nanozyme is further established in a preclinical animal model of Huntington's disease (HD), a prevalent progressive neurodegenerative disorder, which has no effective medication to date. Management of HD in preclinical animal trial using a biocompatible (non-toxic) nanozyme as a part of the metabolic network may uncover a new paradigm in nanozyme based therapeutic strategy.

Rationalization of a traditional liver medicine using systems biology approach and its evaluation in preclinical trial.

'Bottom-up', i.e., molecule to medicine strategy for the discovery of new drugs takes enormous time and cost. In most of the cases, inherent toxicity and undesired side effects of the developed drug hinder its way beyond the early stages of development. In this regard, the systems pharmacology can play an excellent role by reducing the cost and time of drug development through rationalization and/or repurposing of traditional drugs with known side effects. In the present study, our aim was to develop an integrated systems biology method for the prediction of active ingredients of a traditional medicine and their potential targets inside the body. Further, we evaluated the predictive capacity of the developed method in a preclinical animal model. Here, we have prepared a formulation (SKP17LIV01) from an extract of eight medicinal plants traditionally used as liver medicine and identified the constituents using UHPLC-MS technique. Using systems biology approach, we have rationalized the components of the formulation for potential use in the treatment of heavy metal-induced hepatotoxicity. The active ingredients and potential therapeutic targets were also predicted. A detailed biochemical, histopathological and molecular study on the mice model of lead toxicity confirms the efficacy of the formulation as per prediction by the systems pharmacology approach. The study may open a new frontier for re-discovery of drugs that are already used in traditional medicine.

Correction: Manganese neurotoxicity: nano-oxide compensates for ion-damage in mammals.

Correction for 'Manganese neurotoxicity: nano-oxide compensates for ion-damage in mammals' by Aniruddha Adhikari et al., Biomater. Sci., 2019, 7, 4491-4502, DOI: .

A Smart Nanotherapeutic Agent for in†vitro and in†vivo Reversal of Heavy-Metal-Induced Causality: Key Information from Optical Spectroscopy.

Human exposure to heavy metals can cause a variety of life-threatening disorders, affecting almost every organ of the body, including the nervous, circulatory, cardiac, excretory, and hepatic systems. The presence of heavy metal (cause) and induced oxidative stress (effect) are both responsible for the observed toxic effects. The conventional and effective way to combat heavy metal overload diseases is through use of metal chelators. However, they possess several side effects and most importantly they fail to manage the entire causality. In this study, we introduce citrate-functionalized Mn3 O4 nanoparticles (C-Mn3 O4 NPs) as an efficient chelating agent for treatment of heavy metal overload diseases. By means of UV/Vis absorbance and steady-state fluorescence spectroscopic techniques we investigated the efficacy of the NPs in chelation of a model heavy metal, lead (Pb). We also explored the retention of antioxidant properties of the Pb-chelated C-Mn3 O4 NPs using a UV/Vis-assisted DPPH assay. Through CD spectroscopic studies we established that the NPs can reverse the Pb-induced structural modifications of biological macromolecules. We also studied the in vivo efficacy of NPs in Pb-intoxicated C57BL/6j mice. The NPs were not only able to mobilize the Pb from various organs through chelation, but also saved the organs from oxidative damage. Thus, the C-Mn3 O4 NPs could be an effective nanotherapeutic agent for complete reversal of heavy-metal-induced toxicity through chelation of the heavy metal and healing of the associated oxidative stress.

Manganese neurotoxicity: nano-oxide compensates for ion-damage in mammals.

Here, we have compared the behavioral neurotoxicity of a manganese nanoformulation (citrate functionalized Mn3O4 nanoparticles; C-Mn3O4 NPs) with that of the well-known neurotoxicant, ionic Mn, in an animal model. We found that mice administered with C-Mn3O4 NPs showed no signs of a neurobehavioral disorder, but the NPs instead ameliorated Mn-induced neurotoxicity (Parkinson's-like syndrome) through the chelation of excess Mn ions and subsequent reduction of oxidative damage.

Novel one pot synthesis and spectroscopic characterization of a folate-Mn3O4 nanohybrid for potential photodynamic therapeutic application.

Treatment of cancer using nanoparticles made of inorganic and metallic compounds has been increasingly used, owing to their novel intrinsic physical properties and their potential to interact with specific cellular sites, thereby significantly reducing severe secondary effects. In this study, we report a facile strategy for synthesis of folate capped Mn3O4 nanoparticles (FA-Mn3O4 NPs) with high colloidal stability in aqueous media using a hydrothermal method for potential application in photodynamic therapy (PDT) of cancer. The capping of FA to Mn3O4 NPs was confirmed using various spectroscopic techniques. In adenocarcinomic human alveolar basal epithelial cells (A549), the nanohybrid synthesised with a combination of FA and Mn3O4 shows remarkable PDT activity via intracellular ROS generation (singlet oxygen). As established by a DNA fragmentation assay and fluorescence studies, the nanohybrid can cause significant nuclear DNA damage by light induced enhanced ROS generation. In the assessment of Bax, Bcl2 provides strong evidence of apoptotic cellular death. Cumulatively, the outcomes of this study suggest that these newly synthesized FA-Mn3O4 NPs can specifically destroy cells with overexpressed folate receptors, thereby providing a solution in the journey of cancer eradication.

Spectroscopic Studies on Dual Role of Natural Flavonoids in Detoxification of Lead Poisoning: Bench-to-Bedside Preclinical Trial.

Ubiquitousness in the target organs and associated oxidative stress are the most common manifestations of heavy-metal poisoning in living bodies. While chelation of toxic heavy metals is important as therapeutic strategy, scavenging of increased reactive oxygen species, reactive nitrogen species and free radicals are equally important. Here, we have studied the lead (Pb) chelating efficacy of a model flavonoid morin using steady-state and picosecond-resolved optical spectroscopy. The efficacy of morin in presence of other flavonoid (naringin) and polyphenol (ellagic acid) leading to synergistic combination has also been confirmed from the spectroscopic studies. Our studies further reveal that antioxidant activity (2,2-diphenyl-1-picrylhydrazyl assay) of the Pb-morin complex is sustainable compared to that of Pb-free morin. The metal-morin chelate is also found to be significantly soluble compared to that of morin in aqueous media. Heavy-metal chelation and sustainable antioxidant activity of the soluble chelate complex are found to accelerate the Pb-detoxification in the chemical bench (in vitro). Considering the synergistic effect of flavonoids in Pb-detoxification and their omnipresence in medicinal plants, we have prepared a mixture (SKP17LIV01) of flavonoids and polyphenols of plant origin. The mixture has been characterized using high-resolution liquid chromatography assisted mass spectrometry. The mixture (SKP17LIV01) containing 34 flavonoids and 76 other polyphenols have been used to investigate the Pb detoxification in mouse model. The biochemical and histopathological studies on the mouse model confirm the dual action in preclinical studies.