Mayur Temgire - Academia.edu (original) (raw)

Papers by Mayur Temgire

Research paper thumbnail of Selective Induction of Apoptotic Cell Death in Lung Carcinoma Cells by Curcumin loaded PEGylated Lipid Nanoparticles with Minimal Normal Tissue Toxicity: In-Vitro & In-Vivo Toxicity Evaluation by Oral Delivery

Research paper thumbnail of Amyloid-mimicking toxic nanofibers generated via self-assembly of dopamine

Nanoscale

The neurotransmitter dopamine shows oxidation-favored aggregation under physiological mimicked co... more The neurotransmitter dopamine shows oxidation-favored aggregation under physiological mimicked conditions, yielding a well-organized amyloid mimicking cytotoxic nanoarchitecture.

Research paper thumbnail of Optical and structural studies of silver nanoparticles

Radiation Physics and Chemistry, 2004

Gamma radiolysis method was used to prepare polyvinyl alcohol (PVA) capped silver nanoparticles b... more Gamma radiolysis method was used to prepare polyvinyl alcohol (PVA) capped silver nanoparticles by optimizing various conditions like metal ion concentration and polymer (PVA) of different molecular weights. The role of different scavengers was also studied. The decrease in particle size was observed with increase in the molecular weight of capping agent. g-radiolytic method provides silver nanoparticles in fully reduced and highly pure state. XRD (X-ray diffraction) technique confirmed the zero valent state of silver. Optical studies were done using UV-visible spectrophotometer to see the variation of electronic structure of the metal sol. Transmission Electron Microscopic (TEM) studies reveal the fcc geometry. The TEM show clearly split Debye-Scherrer rings. The d values calculated from the diffraction ring pattern are in perfect agreement with the ASTM data. Ag particles less than 10 nm are spherical in shape, whereas the particles above 30 nm have structure of pentagonal biprisms or decahedra, referred to as multiply twinned particles.

Research paper thumbnail of Mercuration of apo-α-lactalbumin: binding of Hg 2+ followed by protein-mediated nanoparticle formation

RSC Adv., 2014

ABSTRACT Nanoparticles and nanocrystals of mercury are formed when Hg2+ salt reacts with apo--la... more ABSTRACT Nanoparticles and nanocrystals of mercury are formed when Hg2+ salt reacts with apo--lactalbumin (apo-α-LA). Reduction followed by nanoparticle formation is further augmented by the protein as it also acts as a coating agent. The initial interaction of Hg2+ with apo-α-LA has been shown by the changes observed in the absorption, emission and CD spectroscopy, where the latter technique also supported structural changes in the protein. Since such structural changes are expected when Hg2+ binds to the protein, the binding was shown by isothermal titration calorimetry (ITC). This was further proven by MALDI which showed mercurated species of protein that has Gaussian distribution exhibiting a weighted average of 6 and 9 Hg2+ ions bound to protein when the apo-α-LA was treated with 10 and 100 equivalents respectively. The molecular dynamics studies revealed the binding of Hg2+ ions followed by the structural changes that occur in the protein. The reaction between Hg2+ and apo-α-LA yields non-crystalline nanoparticles at lower mole ratios of Hg2+ and crystalline ones at higher mole ratios. Both these nanoparticles were proven by extensive TEM studies. The mercury nanocrystals have also been demonstrated by fluorescence microscopy. Thus the protein has the ability to convert Hg2+ to Hg0 as delineated by X-ray photoelectron spectroscopy. The resultant Hg0 cluster is known to be less harmful than the Hg2+ to the organism. All these studies also support the detoxification Hg2+ by apo-α-LA in the form of mercury nanoparticles and nanocrystals.

Research paper thumbnail of Evidence of Rapid Coaggregation of Globular Proteins during Amyloid Formation

Biochemistry, 2014

The question of how an aggregating protein can influence aggregation of other proteins located in... more The question of how an aggregating protein can influence aggregation of other proteins located in its vicinity is particularly significant because many proteins coexist in cells. We demonstrate in vitro coaggregation and cross-seeding of lysozyme, bovine serum albumin, insulin, and cytochrome c during their amyloid formation. The coaggregation process seems to be more dependent on the temperature-induced intermediate species of these proteins and less dependent on their sequence identities. Because amyloid-linked inclusions and plaques are recognized as multicomponent entities originating from aggregation of the associated protein, these findings may add new insights into the mechanistic understanding of amyloid-related pathologies.

Research paper thumbnail of Chain length dependence of polyol synthesis of zinc ferrite nanoparticles: why is diethylene glycol so different?

Dalton Transactions, 2013

Superparamagnetic ZnFe2O4 nanoparticles with size range of 28-38 nm were synthesized by polyol pr... more Superparamagnetic ZnFe2O4 nanoparticles with size range of 28-38 nm were synthesized by polyol process based on use of varying chain length glycols as solvent. We have offered, for the first time, the plausible mechanism behind in situ formation of zinc ferric oxalate hydroxide hydrate [Fe2Zn(C2O4)2(OH)3](+)·4H2O complex from diethylene and polyethylene glycol. We are also reporting, the magnetic properties of above complexes. We have found a ferromagnetic ordering in precursor complex compounds. The intermediate hydrocarbon chain between the oxalato bridged metal cations plays a crucial role in obtaining anomalous magnetic behavior. ZnFe2O4 nanoparticles obtained after annealing the DEGylated precursor complex (precursor complex formed in diethylene glycol) showed the highest superparamagnetic (SPM) behavior (22.4 emu g(-1)) among others. The reasons for anomalous SPM behavior of ZnFe2O4 nanoparticles are explained on the basis of the degree of inversion of the spinel structure, high surface-to-volume ratio, which causes non-collinear spin arrangement in a surface layer and higher oxygen concentration on the surface of dead organic layer, which increases the unpaired valence electrons leading to uncompensated surface spins.

Research paper thumbnail of A case study: Te in ZnSe and Mn-doped ZnSe quantum dots

Research paper thumbnail of Role of Curvature in PEG-Mediated Fusion Between Highly Curved and Un-Curved Membranes

Biophysical Journal, 2010

Research paper thumbnail of Structural Studies on Nonequilibrium Microstructures of Dioctyl Sodium Dodecyl Sulfosuccinate (Aerosol-OT) in p-Toluenesulfonic Acid and Phosphatidylcholine

Advances in Physical Chemistry, 2012

Several microstructures are evolved at the interface when sparingly soluble solid surfactants com... more Several microstructures are evolved at the interface when sparingly soluble solid surfactants come in contact with water. One class of these microstructures is termed as “myelin figures”; these were observed when phosphatidylcholine came in contact with water. Although the myelins are initially simple rod-like, complex forms like helices, coils and so forth. appear in the later stage. Finally, the myelins fuse together to form a complex mosaic-like structure. When studied by taking a cross-section using cryoscanning electron microscopy, it revealed concentric circular pattern inside the myelin figures. The cross-sections of (dioctyl sodium dodecyl sulfosiccinate) AOT/water system myelin internal structures were lost. When p-toluenesulfonic acid (PTS) 2 wt% was present in the water phase, AOT myelins revealed the internal microstructures. It has annular concentric ring-like structure with a core axon at the centre. Further investigation revealed new microstructures for the first time...

Research paper thumbnail of Gamma Radiolytic Formation of Alloyed Ag-Pt Nanocolloids

Advances in Physical Chemistry, 2011

Colloidal dispersions of Ag-Pt composite nanoparticles were prepared by gamma radiolysis techniqu... more Colloidal dispersions of Ag-Pt composite nanoparticles were prepared by gamma radiolysis technique in the presence of nonionic surfactant Brij'97. Simultaneous as well as sequential reduction methods were employed in order to study the structural formation of Ag-Pt bimetallic clusters. Similar shape and trend was observed in optical spectra for both methods. Radiolysis yielded nearly spherical Ag-Pt bimetallic clusters by use of AgNO3instead of AgClO4. The disappearance of the silver resonance and the simultaneous growth of the 260 nm resonance are independent of cluster structure and degree of alloying. To understand formation of Ag-Pt aggregate, the optical studies were also done as a function of amount of dose absorbed, concentration of surfactant, that is, Brij'97. The shape of the absorption spectrum did not change with increase in gamma radiation dose. TEM analysis exhibited fine dispersions of Ag-Pt clusters surrounded by a mantle when capped with Brij'97. The par...

Research paper thumbnail of Genesis of Neurotoxic Hybrid Nanofibers from the Coassembly of Aromatic Amino Acids

ACS Applied Materials & Interfaces

Considering the relevance of accumulation and self-assembly of metabolites and aftermath of biolo... more Considering the relevance of accumulation and self-assembly of metabolites and aftermath of biological consequences, it is important to know whether they undergo coassembly and what properties the resultant hybrid higher-order structures would exhibit. This work reveals the inherent tendency of aromatic amino acids to undergo a spontaneous coassembly process under physiologically mimicked conditions, which yields neurotoxic hybrid nanofibers. Resultant hybrid nanostructures resembled the β-structured conformers stabilized by H-bonds and π-π stacking interactions, which were highly toxic to human neuroblastoma cells. The hybrid nanofibers also showed strong cross-seeding potential that triggered in vitro aggregation of diverse globular proteins and brain extract components, converting the native structures into cross-β-rich amyloid aggregates. The heterogenic nature of the hybrid nanofibers seems crucial for their higher toxicity and faster cross-seeding potential as compared to the homogeneous amino acid nanofibers. Our findings reveal the importance of aromaticity-driven optimized intermolecular arrangements for the coassembly of aromatic amino acids, and the results may provide important clues to the fundamental understanding of metabolite accumulation-related complications.

Research paper thumbnail of Myricetin inhibits amyloid fibril formation of globular proteins by stabilizing the native structures

Colloids and Surfaces B: Biointerfaces

Research paper thumbnail of Dilution-Induced Physico-Chemical Changes of Metal Oxide Nanoparticles Due to Homeopathic Preparation Steps of Trituration and Succussion

Homeopathy

Background Although the presence of starting materials in extreme dilutions of homeopathic medici... more Background Although the presence of starting materials in extreme dilutions of homeopathic medicines has been established, the physico-chemical changes of these materials induced by the manufacturing steps—that is, solid–solid mixing involving grinding (trituration) and slurry mixing involving impact (succussion), followed by dilution—are still unknown. Methods We subjected cupric oxide and zinc oxide nanoparticles (NPs) to the homeopathic processes of trituration and succussion, followed by dilution up to 6 cH. Particle image velocimetry was employed to analyze the fluid motion during succussion and its effect on the NPs. The resulting microstructural and chemical changes at different dilution steps were determined by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy and transmission electron microscopy. Results The succussion triggered multi-sized bubble generation and turbulent fluid motion up to a duration of 400 ms, with maximum average velocity of 0.23 ...

Research paper thumbnail of A biodegradable fluorescent nanohybrid for photo-driven tumor diagnosis and tumor growth inhibition

Nanoscale, Jan 18, 2018

Specific targeting and phototriggered therapy in mouse model have recently emerged as the startin... more Specific targeting and phototriggered therapy in mouse model have recently emerged as the starting point of cancer theragnosis. Herein, we report a bioresponsive and degradable nanohybrid, a liposomal nanohybrid decorated with red emissive carbon dots, for localized tumor imaging and light-mediated tumor growth inhibition. Unsaturated carbon dots (C-dots) anchored to liposomes convert near-infrared (NIR) light into heat and also produce reactive oxygen species (ROS), demonstrating the capability of phototriggered cancer cell death and tumor regression. The photothermal and oxidative damage of breast tumor by the nonmetallic nanohybrid has also been demonstrated. Designed nanoparticles show excellent aqueous dispersibility, biocompatibility, light irradiated enhanced cellular uptake, release of reactive oxygen species, prolonged and specific tumor binding ability and good photothermal response (62 °C in 5 minutes). Safe and localized irradiation of 808 nm light demonstrates significa...

Research paper thumbnail of 3D scaffold induces efficient bone repair: in vivo studies of ultra-structural architecture at the interface

RSC Adv., 2016

Biodegradable designer 3D scaffold bridges critical size defect and induces new bone formation as... more Biodegradable designer 3D scaffold bridges critical size defect and induces new bone formation as revealed by ssNMR, SEM, EDX and μ-CT in rabbit tibial model during healing. No growth factor was needed due to chemical and microstructural cues.

Research paper thumbnail of Photochemically assisted one-pot synthesis of PMMA embedded silver nanoparticles: antibacterial efficacy and water treatment

RSC Adv., 2016

Achievement of simultaneous reduction of bactericidal silver nanoparticles and in situ polymeriza... more Achievement of simultaneous reduction of bactericidal silver nanoparticles and in situ polymerization by photo irradiation is beneficial for water treatment.

Research paper thumbnail of Bioconductive 3D nano-composite constructs with tunable elasticity to initiate stem cell growth and induce bone mineralization

Materials Science and Engineering: C, 2016

Bioactive 3D composites play an important role in advanced biomaterial design to provide molecula... more Bioactive 3D composites play an important role in advanced biomaterial design to provide molecular coupling and improve integrity with the cellular environment of the native bone. In the present study, a hybrid lyophilized polymer composite blend of anionic charged sodium salt of carboxymethyl chitin and gelatin (CMChNa-GEL) reinforced with nano-rod agglomerated hydroxyapatite (nHA) has been developed with enhanced biocompatibility and tunable elasticity. The scaffolds have an open, uniform and interconnected porous structure with an average pore diameter of 157±30μm and 89.47+0.03% with four dimensional X-ray. The aspect ratio of ellipsoidal pores decrease from 4.4 to 1.2 with increase in gelatin concentration; and from 2.14 to 1.93 with decrease in gelling temperature. The samples were resilient with elastic stain at 1.2MPa of stress also decreased from 0.33 to 0.23 with increase in gelatin concentration. The crosslinker HMDI (hexamethylene diisocyanate) yielded more resilient samples at 1.2MPa in comparison to glutaraldehyde. Increased crosslinking time from 2 to 4h in continuous compression cycle show no improvement in maximum elastic stain of 1.2MPa stress. This surface elasticity of the scaffold enables the capacity of these materials for adherent self renewal and cultivation of the NTERA-2 cL.D1 (NT2/D1), pluripotent embryonal carcinoma cell with biomechanical surface, as is shown here. Proliferation with MG-63, ALP activity and Alizarin red mineralization assay on optimized scaffold demonstrated ***p<0.001 between different time points thus showing its potential for bone healing. In pre-clinical study histological bone response of the scaffold construct displayed improved activity of bone regeneration in comparison to self healing of control groups (sham) up to week 07 after implantation in rabbit tibia critical-size defect. Therefore, this nHA-CMChNa-GEL scaffold composite exhibits inherent and efficient physicochemical, mechanical and biological characteristics based on gel concentrations, gelatin mixing and gelling temperature thus points to creating bioactive 3D scaffolds with tunable elasticity for orthopedic applications.

Research paper thumbnail of Establishing the interfacial nano-structure and elemental composition of homeopathic medicines based on inorganic salts: a scientific approach

Homeopathy, 2016

Extremely dilute systems arise in homeopathy, which uses dilution factors 10(60), 10(400) and als... more Extremely dilute systems arise in homeopathy, which uses dilution factors 10(60), 10(400) and also higher. These amounts to potencies of 30c, 200c or more, those are far beyond Avogadro's number. There is extreme skepticism among scientists about the possibility of presence of starting materials due to these high dilutions. This has led modern scientists to believe homeopathy may be at its best a placebo effect. However, our recent studies on 30c and 200c metal based homeopathic medicines clearly revealed the presence of nanoparticles of starting metals, which were found to be retained due to the manufacturing processes involved, as published earlier.(9,10) Here, we use HR-TEM and STEM techniques to study medicines arising from inorganic salts as starting materials. We show that the inorganic starting materials are present as nano-scale particles in the medicines even at 1 M potency (having a large dilution factor of 10(2000)). Thus this study has extended our physicochemical studies of metal based medicines to inorganic based medicines, and also to higher dilution. Further, we show that the particles develop a coat of silica: these particles were seen embedded in a meso-microporous silicate layer through interfacial encapsulation. Similar silicate coatings were also seen in metal based medicines. Thus, metal and inorganic salt based homeopathic medicines retain the starting material as nanoparticles encapsulated within a silicate coating. On the basis of these studies, we propose a universal microstructural hypothesis that all types of homeopathic medicines consist of silicate coated nano-structures dispersed in the solvent.

Research paper thumbnail of Selective Induction of Apoptotic Cell Death in Lung Carcinoma Cells by Curcumin loaded PEGylated Lipid Nanoparticles with Minimal Normal Tissue Toxicity: In-Vitro & In-Vivo Toxicity Evaluation by Oral Delivery

Research paper thumbnail of Amyloid-mimicking toxic nanofibers generated via self-assembly of dopamine

Nanoscale

The neurotransmitter dopamine shows oxidation-favored aggregation under physiological mimicked co... more The neurotransmitter dopamine shows oxidation-favored aggregation under physiological mimicked conditions, yielding a well-organized amyloid mimicking cytotoxic nanoarchitecture.

Research paper thumbnail of Optical and structural studies of silver nanoparticles

Radiation Physics and Chemistry, 2004

Gamma radiolysis method was used to prepare polyvinyl alcohol (PVA) capped silver nanoparticles b... more Gamma radiolysis method was used to prepare polyvinyl alcohol (PVA) capped silver nanoparticles by optimizing various conditions like metal ion concentration and polymer (PVA) of different molecular weights. The role of different scavengers was also studied. The decrease in particle size was observed with increase in the molecular weight of capping agent. g-radiolytic method provides silver nanoparticles in fully reduced and highly pure state. XRD (X-ray diffraction) technique confirmed the zero valent state of silver. Optical studies were done using UV-visible spectrophotometer to see the variation of electronic structure of the metal sol. Transmission Electron Microscopic (TEM) studies reveal the fcc geometry. The TEM show clearly split Debye-Scherrer rings. The d values calculated from the diffraction ring pattern are in perfect agreement with the ASTM data. Ag particles less than 10 nm are spherical in shape, whereas the particles above 30 nm have structure of pentagonal biprisms or decahedra, referred to as multiply twinned particles.

Research paper thumbnail of Mercuration of apo-α-lactalbumin: binding of Hg 2+ followed by protein-mediated nanoparticle formation

RSC Adv., 2014

ABSTRACT Nanoparticles and nanocrystals of mercury are formed when Hg2+ salt reacts with apo--la... more ABSTRACT Nanoparticles and nanocrystals of mercury are formed when Hg2+ salt reacts with apo--lactalbumin (apo-α-LA). Reduction followed by nanoparticle formation is further augmented by the protein as it also acts as a coating agent. The initial interaction of Hg2+ with apo-α-LA has been shown by the changes observed in the absorption, emission and CD spectroscopy, where the latter technique also supported structural changes in the protein. Since such structural changes are expected when Hg2+ binds to the protein, the binding was shown by isothermal titration calorimetry (ITC). This was further proven by MALDI which showed mercurated species of protein that has Gaussian distribution exhibiting a weighted average of 6 and 9 Hg2+ ions bound to protein when the apo-α-LA was treated with 10 and 100 equivalents respectively. The molecular dynamics studies revealed the binding of Hg2+ ions followed by the structural changes that occur in the protein. The reaction between Hg2+ and apo-α-LA yields non-crystalline nanoparticles at lower mole ratios of Hg2+ and crystalline ones at higher mole ratios. Both these nanoparticles were proven by extensive TEM studies. The mercury nanocrystals have also been demonstrated by fluorescence microscopy. Thus the protein has the ability to convert Hg2+ to Hg0 as delineated by X-ray photoelectron spectroscopy. The resultant Hg0 cluster is known to be less harmful than the Hg2+ to the organism. All these studies also support the detoxification Hg2+ by apo-α-LA in the form of mercury nanoparticles and nanocrystals.

Research paper thumbnail of Evidence of Rapid Coaggregation of Globular Proteins during Amyloid Formation

Biochemistry, 2014

The question of how an aggregating protein can influence aggregation of other proteins located in... more The question of how an aggregating protein can influence aggregation of other proteins located in its vicinity is particularly significant because many proteins coexist in cells. We demonstrate in vitro coaggregation and cross-seeding of lysozyme, bovine serum albumin, insulin, and cytochrome c during their amyloid formation. The coaggregation process seems to be more dependent on the temperature-induced intermediate species of these proteins and less dependent on their sequence identities. Because amyloid-linked inclusions and plaques are recognized as multicomponent entities originating from aggregation of the associated protein, these findings may add new insights into the mechanistic understanding of amyloid-related pathologies.

Research paper thumbnail of Chain length dependence of polyol synthesis of zinc ferrite nanoparticles: why is diethylene glycol so different?

Dalton Transactions, 2013

Superparamagnetic ZnFe2O4 nanoparticles with size range of 28-38 nm were synthesized by polyol pr... more Superparamagnetic ZnFe2O4 nanoparticles with size range of 28-38 nm were synthesized by polyol process based on use of varying chain length glycols as solvent. We have offered, for the first time, the plausible mechanism behind in situ formation of zinc ferric oxalate hydroxide hydrate [Fe2Zn(C2O4)2(OH)3](+)·4H2O complex from diethylene and polyethylene glycol. We are also reporting, the magnetic properties of above complexes. We have found a ferromagnetic ordering in precursor complex compounds. The intermediate hydrocarbon chain between the oxalato bridged metal cations plays a crucial role in obtaining anomalous magnetic behavior. ZnFe2O4 nanoparticles obtained after annealing the DEGylated precursor complex (precursor complex formed in diethylene glycol) showed the highest superparamagnetic (SPM) behavior (22.4 emu g(-1)) among others. The reasons for anomalous SPM behavior of ZnFe2O4 nanoparticles are explained on the basis of the degree of inversion of the spinel structure, high surface-to-volume ratio, which causes non-collinear spin arrangement in a surface layer and higher oxygen concentration on the surface of dead organic layer, which increases the unpaired valence electrons leading to uncompensated surface spins.

Research paper thumbnail of A case study: Te in ZnSe and Mn-doped ZnSe quantum dots

Research paper thumbnail of Role of Curvature in PEG-Mediated Fusion Between Highly Curved and Un-Curved Membranes

Biophysical Journal, 2010

Research paper thumbnail of Structural Studies on Nonequilibrium Microstructures of Dioctyl Sodium Dodecyl Sulfosuccinate (Aerosol-OT) in p-Toluenesulfonic Acid and Phosphatidylcholine

Advances in Physical Chemistry, 2012

Several microstructures are evolved at the interface when sparingly soluble solid surfactants com... more Several microstructures are evolved at the interface when sparingly soluble solid surfactants come in contact with water. One class of these microstructures is termed as “myelin figures”; these were observed when phosphatidylcholine came in contact with water. Although the myelins are initially simple rod-like, complex forms like helices, coils and so forth. appear in the later stage. Finally, the myelins fuse together to form a complex mosaic-like structure. When studied by taking a cross-section using cryoscanning electron microscopy, it revealed concentric circular pattern inside the myelin figures. The cross-sections of (dioctyl sodium dodecyl sulfosiccinate) AOT/water system myelin internal structures were lost. When p-toluenesulfonic acid (PTS) 2 wt% was present in the water phase, AOT myelins revealed the internal microstructures. It has annular concentric ring-like structure with a core axon at the centre. Further investigation revealed new microstructures for the first time...

Research paper thumbnail of Gamma Radiolytic Formation of Alloyed Ag-Pt Nanocolloids

Advances in Physical Chemistry, 2011

Colloidal dispersions of Ag-Pt composite nanoparticles were prepared by gamma radiolysis techniqu... more Colloidal dispersions of Ag-Pt composite nanoparticles were prepared by gamma radiolysis technique in the presence of nonionic surfactant Brij'97. Simultaneous as well as sequential reduction methods were employed in order to study the structural formation of Ag-Pt bimetallic clusters. Similar shape and trend was observed in optical spectra for both methods. Radiolysis yielded nearly spherical Ag-Pt bimetallic clusters by use of AgNO3instead of AgClO4. The disappearance of the silver resonance and the simultaneous growth of the 260 nm resonance are independent of cluster structure and degree of alloying. To understand formation of Ag-Pt aggregate, the optical studies were also done as a function of amount of dose absorbed, concentration of surfactant, that is, Brij'97. The shape of the absorption spectrum did not change with increase in gamma radiation dose. TEM analysis exhibited fine dispersions of Ag-Pt clusters surrounded by a mantle when capped with Brij'97. The par...

Research paper thumbnail of Genesis of Neurotoxic Hybrid Nanofibers from the Coassembly of Aromatic Amino Acids

ACS Applied Materials & Interfaces

Considering the relevance of accumulation and self-assembly of metabolites and aftermath of biolo... more Considering the relevance of accumulation and self-assembly of metabolites and aftermath of biological consequences, it is important to know whether they undergo coassembly and what properties the resultant hybrid higher-order structures would exhibit. This work reveals the inherent tendency of aromatic amino acids to undergo a spontaneous coassembly process under physiologically mimicked conditions, which yields neurotoxic hybrid nanofibers. Resultant hybrid nanostructures resembled the β-structured conformers stabilized by H-bonds and π-π stacking interactions, which were highly toxic to human neuroblastoma cells. The hybrid nanofibers also showed strong cross-seeding potential that triggered in vitro aggregation of diverse globular proteins and brain extract components, converting the native structures into cross-β-rich amyloid aggregates. The heterogenic nature of the hybrid nanofibers seems crucial for their higher toxicity and faster cross-seeding potential as compared to the homogeneous amino acid nanofibers. Our findings reveal the importance of aromaticity-driven optimized intermolecular arrangements for the coassembly of aromatic amino acids, and the results may provide important clues to the fundamental understanding of metabolite accumulation-related complications.

Research paper thumbnail of Myricetin inhibits amyloid fibril formation of globular proteins by stabilizing the native structures

Colloids and Surfaces B: Biointerfaces

Research paper thumbnail of Dilution-Induced Physico-Chemical Changes of Metal Oxide Nanoparticles Due to Homeopathic Preparation Steps of Trituration and Succussion

Homeopathy

Background Although the presence of starting materials in extreme dilutions of homeopathic medici... more Background Although the presence of starting materials in extreme dilutions of homeopathic medicines has been established, the physico-chemical changes of these materials induced by the manufacturing steps—that is, solid–solid mixing involving grinding (trituration) and slurry mixing involving impact (succussion), followed by dilution—are still unknown. Methods We subjected cupric oxide and zinc oxide nanoparticles (NPs) to the homeopathic processes of trituration and succussion, followed by dilution up to 6 cH. Particle image velocimetry was employed to analyze the fluid motion during succussion and its effect on the NPs. The resulting microstructural and chemical changes at different dilution steps were determined by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy and transmission electron microscopy. Results The succussion triggered multi-sized bubble generation and turbulent fluid motion up to a duration of 400 ms, with maximum average velocity of 0.23 ...

Research paper thumbnail of A biodegradable fluorescent nanohybrid for photo-driven tumor diagnosis and tumor growth inhibition

Nanoscale, Jan 18, 2018

Specific targeting and phototriggered therapy in mouse model have recently emerged as the startin... more Specific targeting and phototriggered therapy in mouse model have recently emerged as the starting point of cancer theragnosis. Herein, we report a bioresponsive and degradable nanohybrid, a liposomal nanohybrid decorated with red emissive carbon dots, for localized tumor imaging and light-mediated tumor growth inhibition. Unsaturated carbon dots (C-dots) anchored to liposomes convert near-infrared (NIR) light into heat and also produce reactive oxygen species (ROS), demonstrating the capability of phototriggered cancer cell death and tumor regression. The photothermal and oxidative damage of breast tumor by the nonmetallic nanohybrid has also been demonstrated. Designed nanoparticles show excellent aqueous dispersibility, biocompatibility, light irradiated enhanced cellular uptake, release of reactive oxygen species, prolonged and specific tumor binding ability and good photothermal response (62 °C in 5 minutes). Safe and localized irradiation of 808 nm light demonstrates significa...

Research paper thumbnail of 3D scaffold induces efficient bone repair: in vivo studies of ultra-structural architecture at the interface

RSC Adv., 2016

Biodegradable designer 3D scaffold bridges critical size defect and induces new bone formation as... more Biodegradable designer 3D scaffold bridges critical size defect and induces new bone formation as revealed by ssNMR, SEM, EDX and μ-CT in rabbit tibial model during healing. No growth factor was needed due to chemical and microstructural cues.

Research paper thumbnail of Photochemically assisted one-pot synthesis of PMMA embedded silver nanoparticles: antibacterial efficacy and water treatment

RSC Adv., 2016

Achievement of simultaneous reduction of bactericidal silver nanoparticles and in situ polymeriza... more Achievement of simultaneous reduction of bactericidal silver nanoparticles and in situ polymerization by photo irradiation is beneficial for water treatment.

Research paper thumbnail of Bioconductive 3D nano-composite constructs with tunable elasticity to initiate stem cell growth and induce bone mineralization

Materials Science and Engineering: C, 2016

Bioactive 3D composites play an important role in advanced biomaterial design to provide molecula... more Bioactive 3D composites play an important role in advanced biomaterial design to provide molecular coupling and improve integrity with the cellular environment of the native bone. In the present study, a hybrid lyophilized polymer composite blend of anionic charged sodium salt of carboxymethyl chitin and gelatin (CMChNa-GEL) reinforced with nano-rod agglomerated hydroxyapatite (nHA) has been developed with enhanced biocompatibility and tunable elasticity. The scaffolds have an open, uniform and interconnected porous structure with an average pore diameter of 157±30μm and 89.47+0.03% with four dimensional X-ray. The aspect ratio of ellipsoidal pores decrease from 4.4 to 1.2 with increase in gelatin concentration; and from 2.14 to 1.93 with decrease in gelling temperature. The samples were resilient with elastic stain at 1.2MPa of stress also decreased from 0.33 to 0.23 with increase in gelatin concentration. The crosslinker HMDI (hexamethylene diisocyanate) yielded more resilient samples at 1.2MPa in comparison to glutaraldehyde. Increased crosslinking time from 2 to 4h in continuous compression cycle show no improvement in maximum elastic stain of 1.2MPa stress. This surface elasticity of the scaffold enables the capacity of these materials for adherent self renewal and cultivation of the NTERA-2 cL.D1 (NT2/D1), pluripotent embryonal carcinoma cell with biomechanical surface, as is shown here. Proliferation with MG-63, ALP activity and Alizarin red mineralization assay on optimized scaffold demonstrated ***p<0.001 between different time points thus showing its potential for bone healing. In pre-clinical study histological bone response of the scaffold construct displayed improved activity of bone regeneration in comparison to self healing of control groups (sham) up to week 07 after implantation in rabbit tibia critical-size defect. Therefore, this nHA-CMChNa-GEL scaffold composite exhibits inherent and efficient physicochemical, mechanical and biological characteristics based on gel concentrations, gelatin mixing and gelling temperature thus points to creating bioactive 3D scaffolds with tunable elasticity for orthopedic applications.

Research paper thumbnail of Establishing the interfacial nano-structure and elemental composition of homeopathic medicines based on inorganic salts: a scientific approach

Homeopathy, 2016

Extremely dilute systems arise in homeopathy, which uses dilution factors 10(60), 10(400) and als... more Extremely dilute systems arise in homeopathy, which uses dilution factors 10(60), 10(400) and also higher. These amounts to potencies of 30c, 200c or more, those are far beyond Avogadro's number. There is extreme skepticism among scientists about the possibility of presence of starting materials due to these high dilutions. This has led modern scientists to believe homeopathy may be at its best a placebo effect. However, our recent studies on 30c and 200c metal based homeopathic medicines clearly revealed the presence of nanoparticles of starting metals, which were found to be retained due to the manufacturing processes involved, as published earlier.(9,10) Here, we use HR-TEM and STEM techniques to study medicines arising from inorganic salts as starting materials. We show that the inorganic starting materials are present as nano-scale particles in the medicines even at 1 M potency (having a large dilution factor of 10(2000)). Thus this study has extended our physicochemical studies of metal based medicines to inorganic based medicines, and also to higher dilution. Further, we show that the particles develop a coat of silica: these particles were seen embedded in a meso-microporous silicate layer through interfacial encapsulation. Similar silicate coatings were also seen in metal based medicines. Thus, metal and inorganic salt based homeopathic medicines retain the starting material as nanoparticles encapsulated within a silicate coating. On the basis of these studies, we propose a universal microstructural hypothesis that all types of homeopathic medicines consist of silicate coated nano-structures dispersed in the solvent.