Development of injectable upconversion nanoparticle-conjugated doxorubicin theranostics electrospun nanostructure for targeted photochemotherapy in breast cancer.

Nanotheranostic-based photochemotherapies with targeted drug delivery have considerably surfaced in cancer therapy. In the presented work, polyethyleneimine-coated upconversion nanoparticles were engineered to conjugate covalently with doxorubicin. Upconversion nanoparticles (UCNP)-Doxorubicin (DOX)/synthesized epidermal growth factor receptor-targeting peptide blended with polymer composite was electrospun and formulated as the injectable dosage form. The size of the UCNP and the nanofiber diameter were assessed as 26.75 ± 1.54 and 162 ± 2.82 nm, respectively. The optimized ratio of dopants resulted in UCNP photoluminescence with maximum emission intensity at around 800 nm upon 980 nm excitation wavelength. The paramagnetic nature of UCNPs and amide conjugation with the drug was confirmed analytically. The loading capacity of UCNP for doxorubicin was determined to be 54.56%, while nanofibers exhibited 98.74% capacity to encapsulate UCNP-DOX. The release profile of UCNP-DOX from nanofiber formulation ranged from sustained to controlled, with relative enhancement in acidic conditions. The nanofiber demonstrated good mechanical strength, robust swelling, and degradation rate. Biocompatibility tests showed more than 90% cell viability on L929 and NIH/3T3 cell lines with UCNP-DOX@NF/pep nanoformulation. The IC50 values of 2.15 ± 0.54, 2.87 ± 0.67, and 3.42 ± 0.45 µg/mL on MDA-MB-231, 4T1, and MCF-7 cancer cell line, respectively, with a significant cellular uptake, has been reported. The UCNP protruded a ≈62.7°C temperature rise within 5 min of 980 nm laser irradiation and a power density of 0.5 W cm-2. The nanoformulation induced reactive oxygen species of 65.67% ± 3.21% and apoptosis by arresting the cell cycle sub-G1 phase. The evaluation conveys the effectiveness of the developed injectable theranostic delivery system in cancer therapy.

Neuroprotective effects of nanogold-based Ayurveda medicine Suvarna Bhasma against rotenone-induced Parkinson's-like model.

BACKGROUND: Neurodegenerative diseases have been one of the major concerns for human health. Genetic and environmental factors are believed to be responsible for neuronal diseases such as Parkinson's disease, Alzheimer's disease, and Huntington's disease. It is difficult to restore normal nervous function after neurodegeneration; hence, prevention could be the best strategy against these diseases. Ayurved medicines such as Suvarna Bhasma (SB) have enormous potential to treat these neurological diseases. AIM: The aim of this study is to examine the protective effect of SB against rotenone-induced Parkinson's-like model in zebrafish. MATERIALS AND METHODS: In this study, we induced Parkinson's-like disease model in zebrafish by inducing it with rotenone (7 µg/L). We examined the behavioural, proteomics and dopamine alterations of rotenone induced zebrafish of SB pre-treated group as compared to the control group. RESULTS: The behavioural experiments showed that due to rotenone exposure, Parkinson's-like behavioural abnormality was induced in zebrafish. However, because of SB treatment, this behavioural abnormality was reduced. The proteomics study of zebrafish brains clearly showed that the SB-treated group was not significantly affected due to rotenone exposure. However, in the SB non-treated group, expression of nine proteins that are linked to Parkinson's disease (gene name: sncgb, ywhae1, ywhah, uchl1, ywhaba, psma6a, ywhabl, ywhaqb, and ywhabb) were differentially expressed after rotenone exposure. Finally, prevention of dopamine alteration in SB-treated fish brains confirmed the protective action of SB against rotenone-induced Parkinson's-like model in zebrafish. CONCLUSIONS: This study finds that Suvarna Bhasma has neuroprotective effects against Parkinson's-like disease model.

Natural bone inspired core-shell triple-layered gel/PCL/gel 3D printed scaffolds for bone tissue engineering.

Despite technological advancements in bone tissue engineering, it is still a challenge to fabricate a scaffold with high bioactivity as well as high mechanical strength that can promote osteogenesis as well as bear load. Here we developed a 3D printed gel-polymer multi-layered hybrid scaffold. The innermost layer is porous gel-based framework made of gelatin/carboxymethyl-chitin/nano-hydroxyapatite and is cryogenically 3D printed. Further, the second and middle layer of micro-engineered polycaprolactone (PCL) is infused in the gel with controlled penetration and tuneable coating thickness. The PCL surface is further coated with a third and final thin layer of gel matrix used for the first layer. This triple-layered structure demonstrates compression strength and modulus of 13.07 ± 1.15 MPa and 21.8 ± 0.82 MPa, respectively, post 8 weeks degradation which is >3000% and >700% than gel scaffold. It also shows degradation of 6.84 ± 0.70% (83% reduction than gel scaffold) after 12 weeks and swelling of 69.09 ± 6.83% (81% reduction) as compared to gel scaffolds. Further, nearly 300%, 250%, 50%, and 440% increase in cellular attachment, proliferation, protein generation, and mineralization, respectively are achieved as compared to only PCL scaffolds. Thus, these hybrid scaffolds offer high mechanical strength, slow degradation rate, high bioactivity, and high osteoconductivity. These multifunctional scaffolds have potential for reconstructing non-load-bearing bone defects like sinus lift, jaw cysts, and moderate load-bearing like reconstructing hard palate, orbital palate, and other craniomaxillofacial bone defects.

Theranostic magnetic nanoparticles enhance DNA damage and mitigate doxorubicin-induced cardio-toxicity for effective multi-modal tumor therapy.

The chemo-therapeutic efficacy of Doxorubicin (Dox), a potent anti-cancer drug used in the treatment of several solid tumors, is severely compromised by its cardio-toxicity. To overcome this shortcoming and exploit the utmost theranostic potential of nano-formulations, magnetic nanoparticles co-encapsulated with Dox and indocyanine green (ICG) in a liposomal carrier and tagged with cyclic RGD peptide were rationally designed and synthesized. These magneto-liposomes (T-LMD) showed αvß3-integrin receptor targeting and higher cyto-toxicity in several cancer cell lines (i.e. lung, breast, skin, brain and liver cancer) in combination with or without gamma radiation or magnetic hyperthermia therapy as compared to clinical liposomal nano-formulation of Dox (Lippod™). Mechanism of chemo-radio-sensitization was found to involve activation of JNK mediated pro-apoptotic signaling axis and delayed repair of DNA double strand breaks. Real time imaging of ICG labeled T-LMD suggested ~6-18 fold higher tumor accumulation of T-LMD as compared to off-target organs (kidney, liver, spleen, intestine, lungs and heart) and resulted in its higher combinatorial (chemo-radio-hyperthermia) tumor therapy efficacy as compared to Lippod™. Moreover, T-LMD showed insignificant toxicity to the heart tissue as suggested by serum levels of CK-MB, histo-pathological analysis, anti-oxidant enzyme activities (Catalase and GST) and markers of cardiac fibrosis, suggesting its potential for targeted multi-modal therapy of cancer.

RanGTPase links nucleo-cytoplasmic transport to the recruitment of cargoes into small extracellular vesicles.

Small extracellular vesicle (sEV)-mediated intercellular communication regulates multiple aspects of growth and development in multicellular organisms. However, the mechanism underlying cargo recruitment into sEVs is currently unclear. We show that the key nucleo-cytoplasmic transport (NCT) protein-RanGTPase, in its GTP-bound form (RanGTP), is enriched in sEVs secreted by mammalian cells. This recruitment of RanGTP into sEVs depends on the export receptor CRM1 (also called XPO1). The recruitment of GAPDH, a candidate cargo protein, into sEVs is regulated by the RanGTP-CRM1axis in a nuclear export signal (NES)-dependent manner. Perturbation of NCT through overexpression or depletion of nuclear transport components affected the recruitment of Ran, CRM1 and GAPDH into sEVs. Our studies, thus, suggest a link between NCT, particularly the Ran-CRM1 axis, and recruitment of NES-containing cargoes into the sEVs. Collectively, these findings implicate RanGTPase as a link between NCT and sEV mediated intercellular communication.

X-ray computed microtomography datasets for osteogenic nanofibrous coated titanium implants.

Surface modifications of titanium implant influences the quality of osseointegration and are associated with favourable treatment prognosis in orthopaedic and cranio-maxillofacial cases. Hence, unlike previous works, the peri-implant region details of our novel osteogenic nanofibrous coated implants placed in rabbits (n = 6 + 1) were recorded over a 12-week period using a micro-CT imaging system. In this unique contribution, we have created a computed tomography (CT) library of rabbit's tibiae anatomy with osteogenic nanofibrous coated/uncoated implants and are introductory useful assets for investigating the correlation between osteogenic nanofibers coated implants and its effect on improved osseointegration. Apart from using this CT dataset to conduct serial 2D image studies, three-dimensional (3D) reconstructions, assessing segmentation algorithms and developing adequate image quantitation tools, there may be positive applications of these in comparative investigations of similar or related preclinical as well as future clinical studies, further design planning, development etc. required for evolution of implants beyond the present state of art.

Improved osteoblast function on titanium implant surfaces coated with nanocomposite Apatite-Wollastonite-Chitosan- an experimental in-vitro study.

BACKGROUND: There is a continuous research in the area of biomimetic coatings on the titanium (Ti) implant surfaces for improved survival and long-term successful outcomes in the field of dentistry and orthopedics. In-vitro approaches are ideal systems for studying cell-material interactions without complexity and interference observed in in-vivo models. PURPOSE: The present study was undertaken to evaluate the osteoblast characteristics and function on Ti substrates coated with the novel composite coating of ceramic apatite-wollastonite (AW) and polymer chitosan. MATERIALS AND METHODS: Ti substrate coated with composite AW-Chitosan was synthesized, using electrophoretic deposition. MG-63 cells were seeded onto the coated substrates and cellular morphology and growth was assessed using Scanning Electron Microscopy (SEM) and Laser Scanning Microscopy (LSM). Osteocalcin expression of the seeded cells was assessed by FITC tagging and LSM analysis. Alizarin Red S staining and Confocal LSM (CSLM) analysis was used to study the in-vitro mineralization on the titanium samples. RESULTS: The AW-Chitosan coating on Ti samples by electrophoretic deposition exerted significant positive influence on cell proliferation, growth and mineralization as compared to uncoated titanium samples. Scanning electron microscopy and laser confocal microscopy experiments revealed that the coating was non-toxic to cells, enhanced adhesion and proliferation of MG-63 cells. Increased functional activity was observed by increased production of bone-specific protein osteocalcin and mineralized calcium through day 7 and 14. CONCLUSIONS: The present study underscores that optimal inorganic-organic phase nanocomposite crack-free coating created on Ti by simple, cost-effective electrophoretic deposition technique may have osteoconductive potential and may have wide application in the field of implantology. Graphical abstract.

Explaining Ayurvedic preparation of Rasasindura, its toxicological effects on NIH3T3 cell line and zebrafish larvae.

Rasasindura is a mercury-based medicinal formulation that contains HgS (>99%). Although cinnabar ore was a well-known mineral in the past, the Ayurvedic practitioner adopted a critical and tedious procedure for the preparation of Rasasindura. Therefore, it is essential to understand the Ayurvedic process in the perspective of material science. Further, a toxicity study is also required as mercury is the main component in Rasasindura. Here, in the present study, we characterized Rasasindura and one of its intermediates (Kajjali) to understand the physicochemical changes that occur in the Ayurvedic process. Furthermore, we have assessed the toxicity of Kajjali and Rasasindura in NIH3T3 cell lines and zebrafish larvae. XRD analysis of Rasasindura confirms it as a highly pure α-HgS with size ranges from nano to micron sizes (starting from ∼80 nm). Whereas, Kajjali is a ß-HgS having lower size ranges (starting from ∼30 nm). Rasasindura did not show significant cytotoxicity on NIH3T3 cell line up to 75 ppm, whereas for Kajjali, cytotoxicity was observed above 20 ppm. The higher toxicity of Kajjali is due to higher penetration of particles into the cells. However, in zebrafish larvae, even at too high concentrations (1000 ppm), both Rasasindura and Kajjali did not show any toxicity or morphological changes. This study concludes that Rasasindura is not toxic up to a reasonable concentration. Further, these two drugs did not contain toxic organic mercuric compound; otherwise, it could have been lethal to the zebrafish larvae.

Concomitant Effect of Quercetin- and Magnesium-Doped Calcium Silicate on the Osteogenic and Antibacterial Activity of Scaffolds for Bone Regeneration.

Quercetin is a bioflavonoid which has a broad spectrum of biological activity. Due to its lower chemical stability, it is usually encapsulated, or a metal-quercetin complex is formed to enhance its biological activity at a lower concentration. Here, our novel approach was to form a quercetin complex to magnesium-doped calcium silicate (CMS) ceramics through a coprecipitation technique so as to take advantage of quercetin's antibacterial activity within the antibacterial and osteogenic potential of the silicate. Due to quercetin's inherent metal-chelating ability, (Ca+Mg)/Si increased with quercetin concentration. Quercetin in magnesium-doped calcium silicate ceramic showed concentration-dependent pro-oxidant and antioxidant activity in SaOS-2 with respect to quercetin concentration. By optimizing the relative concentration, we were able to achieve 3-fold higher proliferation and 1.6-fold higher total collagen at day 14, and a 1.7-fold higher alkaline phosphatase production at day 7 with respect to polycaprolactone/polyvinylpyrrolidone (PCL/PVP) scaffold. Quercetin is effective against Gram-positive bacteria such as S. aureus. Quercetin is coupled with CMS provided similar effect with lower quercetin concentration than quercetin alone. Quercetin reduced bacterial adhesion, proliferation and biofilm formation. Therefore, quercetin-coupled magnesium-doped calcium silicate not only enhanced osteogenic potential, but also reduced bacterial adhesion and proliferation.

Chemical Fingerprinting of Polymers Using Electron Energy-Loss Spectroscopy.

Electron energy-loss spectroscopy (EELS) is becoming an important tool in the characterization of polymeric materials. The sensitivity of EELS to changes in the chemical structure of polymeric materials dictates its applicability. In particular, it is important for compositional analysis to have reference spectra of pure components. Here, we report the spectra of the carbon K-edge of six polymers (polyethylene, polypropylene, polybutylene terephthalate, and polylactic acid) including copolymers (styrene acrylonitrile and acrylonitrile butadiene styrene), to be used as reference spectra for future EELS studies of polymers. We have successfully decomposed the carbon K-edge of each of the polymers and assigned the observed peaks to bonding transitions. The spectra have been acquired in standard experimental conditions, and electron beam damage has been taken into account during establishment of spectral-structural relationships. We found that the more commonly available low-energy resolution spectrometers are adequate to chemically fingerprint linear saturated hydrocarbons such as PE, PP, and PLA. We have thus moved a step closer toward creating an atlas of polymer EELS spectra, which can be subsequently used for chemical bond mapping of polymeric materials with nanoscale spatial resolution.

"Viscotaxis"- directed migration of mesenchymal stem cells in response to loss modulus gradient.

Directed cell migration plays a crucial role in physiological and pathological conditions. One important mechanical cue, known to influence cell migration, is the gradient of substrate elastic modulus (E). However, the cellular microenvironment is viscoelastic and hence the elastic property alone is not sufficient to define its material characteristics. To bridge this gap, in this study, we investigated the influence of the gradient of viscous property of the substrate, as defined by loss modulus (G″) on cell migration. We cultured human mesenchymal stem cells (hMSCs) on a collagen-coated polyacrylamide gel with constant storage modulus (G') but with a gradient in the loss modulus (G″). We found hMSCs to migrate from high to low loss modulus. We have termed this form of directional cellular migration as "Viscotaxis". We hypothesize that the high loss modulus regime deforms more due to creep in the long timescale when subjected to cellular traction. Such differential deformation drives the observed Viscotaxis. To verify our hypothesis, we disrupted the actomyosin contractility with myosin inhibitor blebbistatin and ROCK inhibitor Y27632, and found the directional migration to disappear. Further, such time-dependent creep of the high loss material should lead to lower traction, shorter lifetime of the focal adhesions, and dynamic cell morphology, which was indeed found to be the case. Together, findings in this paper highlight the importance of considering the viscous modulus while preparing stiffness-based substrates for the field of tissue engineering. STATEMENT OF SIGNIFICANCE: While the effect of substrate elastic modulus has been investigated extensively in the context of cell biology, the role of substrate viscoelasticity is poorly understood. This omission is surprising as our body is not elastic, but viscoelastic. Hence, the role of viscoelasticity needs to be investigated at depth in various cellular contexts. One such important context is cell migration. Cell migration is important in morphogenesis, immune response, wound healing, and cancer, to name a few. While it is known that cells migrate when presented with a substrate with a rigidity gradient, cellular behavior in response to viscoelastic gradient has never been investigated. The findings of this paper not only reveal a completely novel cellular taxis or directed migration, it also improves our understanding of cell mechanics significantly.

Ethanol affects fibroblast behavior differentially at low and high doses: A comprehensive, dose-response evaluation.

This study aims to develop a comprehensive understanding of effects of low and high doses of ethanol on cellular biochemistry and morphology. Here, fibroblast cells are exposed to ethanol of varied concentrations [0.005-10 % (v/v)] to investigate cellular activity, cytoskeletal organization, cellular stiffness, mitochondrial structure, and real-time behavior. Our results indicate a sharp difference in cellular behavior above and below 1 % ethanol concentration. A two-fold increase in MTT activity at low doses is observed, whereas at high doses it decreases. This increased activity at low doses does not involve cell proliferation changes or mitochondrial impairment, as seen at higher doses. Moreover, the study identifies different types of mitochondrial structure impairment at high doses. Morphologically, cells demonstrate a gradual change in cytoskeletal organization and an increase in cell stiffness with increase in doses. Cells exhibit adaptation to sub-toxic doses of ethanol, wherein recovery from ethanol-induced stress is a dose-dependent phenomenon. Cell survival at low doses and toxicity at higher doses are attributed to mild and strong oxidative stress, respectively. Overall, the study provides a comprehensive understanding of dose-dependent effects of ethanol, manifesting its biphasic or hormetic response, biochemically, at low doses and illustrating its toxicological effects at higher doses.

Physicochemical Variation in Nanogold-Based Ayurved Medicine Suvarna Bhasma Produced by Various Manufacturers Lead to Different In Vivo Bioaccumulation Profiles.

Suvarna Bhasma (SB) is a gold particle-based medicine that is used in Ayurved to treat tuberculosis, arthritis and nervous diseases. Traditionally, the Ayurved preparation processes of SB do exist, but they are all long, tedious and involve several steps. Due to this, there is a possibility of bypassing the necessary Ayurved processes or non-adherence to all steps or use of synthetic gold particles. Our aim is to characterize 5 commercial SB preparations from 5 different manufacturers. A comparative physicochemical, pharmacokinetic (PK) and bioaccumulation study was carried out on all the 5 SB preparations. The general appearance such as color and texture of these 5 samples were different from each other. The size, shape and gold concentration (from 32-98 wt%) varied among all the 5 SBs. The accumulation of ionic gold in zebrafish and gold concentration profiles in rat blood were found to be significantly different for all the 5 SBs. Non-compartmental PK model obtained from the concentration-time profile showed significant differences in various PK parameters such as peak concentration (Cmax), half-life (t1/2) and terminal elimination slope (λz) for all the 5 SB preparations. SB-B showed the highest Cmax (8.55 µg/L), whereas SB-D showed the lowest Cmax (4.66 µg/L). The dissolution of ionic gold from SBs in zebrafish tissue after the oral dose had a 5.5-fold difference between the highest and lowest ionic gold concentrations. All the 5 samples showed distinct physicochemical and biological properties. Based on characteristic microscopic morphology, it was found that 2 preparations among them were suspected of being manufactured by non-adherence to the mentioned Ayurved references.

Multiscale porosity in a 3D printed gellan-gelatin composite for bone tissue engineering.

The aim of this work was to develop a complex-shaped gelatin-gellan composite scaffold with multiscale porosity using a combination of cryogenic 3D printing and lyophilization for bone tissue engineering. Cryogenic 3D printing was used to fabricate a low-concentration composite of complex-shaped macroporous gelatin-gellan structures with a pore size of 919 ± 89 µm. This was followed by lyophilization to introduce micropores of size 20-250 µm and nanometre-level surface functionalities, thus achieving a hierarchical porous structure. These multiscale porous scaffolds (GMu) were compared with two other types of scaffolds having only microporosity (GMi) and macroporosity (GMa) with regard to their physical andin vitrobiological properties. GMu scaffolds were found to be better than GMi and GMa in terms of swelling percentage, degradation rate, uniform pore distribution, cellular infiltration, attachment, proliferation, protein generation and mineralization. In conclusion, we have developed a controlled hierarchical bone-like structure, biomimicking natural bone, together with a reproducible process of manufacture by coupling soft hydrogel 3D printing with lyophilization. This enables the development of complex-shaped patient-specific 3D printed hydrogel scaffolds with enhanced performancein vitroand great potential in the fields of tissue engineering, bioprinting and regenerative medicine.

Viscoelastic substrate decouples cellular traction force from other related phenotypes.

Survival and maintenance of normal physiological functions depends on continuous interaction of cells with its microenvironment. Cells sense the mechanical properties of underlying substrate by applying force and modulate their behaviour in response to the resistance offered by the substrate. Most of the studies addressing cell-substrate mechanical interactions have been carried out using elastic substrates. Since tissues within our body are viscoelastic in nature, here we explore the effect of substrate's viscoelasticity on various properties of mesenchymal stem cells. Here, we used two sets of polyacrylamide substrates having similar storage modulus (G' = 1.1-1.6 kPa) but different loss modulus (G" = 45 Pa and 300 Pa). We report that human mesenchymal stem cells spread more but apply less force on the viscoelastic substrate (substrate with higher loss modulus). We further investigated the effect of substrate viscoelasticity on the expression of other contractility-associated proteins such as focal adhesion (FA) proteins (Vinculin, Paxillin, Talin), cytoskeletal proteins (actin, mysion, intermediate filaments, and microtubules) and mechano-sensor protein Yes-Associated Protein (YAP). Our results show that substrate viscoelasticity decouples cellular traction from other known traction related phenotypes.

Probing Kinetics and Mechanism of Formation of Mixed Metallic Nanoparticles in a Polymer Membrane by Galvanic Replacement between Two Immiscible Metals: Case Study of Nickel/Silver Nanoparticle Synthesis.

Galvanic replacement between metals has received notable research interest for the synthesis of heterometallic nanostructures. The growth pattern of the nanostructures depends on several factors such as extent of lattice mismatch, adhesive interaction between the metals, cohesive forces of the individual metals, etc. Due to the difficulties in probing ultrafast kinetics of the galvanic replacement reaction and particle growth in solution, real-time mechanistic investigations are often limited. As a result, the growth mechanism of one metal on the surface of another metal at the nanoscale is poorly understood so far. In the present work, we could successfully probe the galvanic replacement of silver ions with nickel nanoparticles, stabilized in a polymer membrane, using two complementary methods, namely, small-angle X-ray scattering (SAXS) and radiolabeling, and the results are supported by density functional theory (DFT) computations. The silver-nickel system has been chosen for the present investigation because of the high degree of bulk immiscibility caused by the large lattice mismatch (15.9%) and the weak adhesive interaction, which makes it a perfect model system for immiscible metal pairs. Membrane, as a host medium, plays a crucial role in retarding the kinetics of atomic and particle rearrangements (nucleation and growth) due to slower mobility of the atoms (monomers) and particles within the polymer network. This allowed us to examine the real-time concentration of silver monomers during galvanic replacement of silver ions with nickel nanoparticles and evolution of Ni/Ag nanoparticles. From combined experiment and DFT computations, it has been demonstrated, for the first time to the best of our knowledge, that the majority of silver atoms, which are produced on the nickel nanoparticle surface by galvanic reactions, do not form traditional core-shell nanostructures with nickel and undergo a self-governing sequential nucleation and growth of silver nanoparticles via formation of intermediate prenucleation silver clusters, leading to the formation of mixed metallic nanoparticles in the membrane. The surface of NiNPs has a heterogeneous effect on the silver nucleation pathway, which is evident from the reduced critical free energy barrier of nucleation (ΔGcrit). The present work establishes an original mechanistic pathway based on a sequential nucleation model for formation of mixed metallic nanoparticles by the galvanic replacement route, which opens up future possibilities for size-controlled synthesis in mixed systems.

Adaptive mechanisms induced by sparingly soluble mercury sulfide (HgS) in zebrafish: Behavioural and proteomics analysis.

Mercury (Hg) causes great health concerns due to its extreme neurotoxicity. However, here we show that pretreatment of sparingly soluble mercury compound (HgS) could induce adaptive mechanisms in zebrafish, which can resist the neurotoxic effects of mercury chloride (HgCl2). In this study, zebrafish were treated with HgS (in the form of 99% HgS arising from traditional Ayurvedic medicine Rasasindura (RS), chosen for its particle and crystallite sizes). This work was prompted by the traditional use of this form of HgS to treat nervous and immune-related diseases. Our investigation on zebrafish behaviour showed that RS pretreated fish group (RS-HG) was less severely affected by HgCl2 exposure, as compared to the RS non-treated (VC-HG) group. Further, biochemical tests showed that RS pretreatment prevents alteration of reactive oxygen species (ROS), acetylcholinesterase (AChE), and cortisol as compared to the VC-HG group. Proteomics and bioinformatics studies of zebrafish brain tissues suggested that Rasasindura (RS-HG group) protects alteration of various protein expression related to KEGG pathways, including citrate cycle (TCA cycle) and glutathione metabolism that are directly or indirectly linked to the oxidative stress, against HgCl2 induced neurotoxicity. We found that adaptive mechanisms were initiated by the initiation of response to stress (enrichment of GO:0006950 pathway), due to the accumulation of a small amount of ionic Hg (60 ± 10 ng/g) after 15 days of RS treatment. These adaptive mechanisms avoid further adverse neurotoxicity of HgCl2. Thus, HgS (RS) pretreatment can induce protective effects in zebrafish.

Three Dimensional Quercetin-Functionalized Patterned Scaffold: Development, Characterization, and In Vitro Assessment for Neural Tissue Engineering.

Regeneration of injured neuronal areas is a big challenge owing to the complex structure and function of the nervous system along with the limited regeneration capacity of neural cells. Recent reports show that patterned and functionalized scaffolds could control neural cell directional growth. In this study, aligned nanofibers (ANFs) were fabricated using a versatile and cost-effective approach, electrospinning, and further processed to make a patterned hybrid scaffold (HANF). The patterned scaffold had circular rings of ANFs reinforced in a biocompatible gellan-gelatin hydrogel matrix to provide adequate mechanical strength and contact guidance for adhesion and growth of neural cells in vitro. Quercetin was loaded into the nanofibrous scaffold to provide a functional agent that supported regeneration of neural cells. The reinforced ANFs enhanced the mechanical strength of the scaffold and provided a cylindrical nerve conduit structure to support neuronal cell growth. The influence of scaffold topology on cell behavior was assessed in in vitro cell culture conditions that revealed that the functionalized patterned scaffolds favored directed neurite cell growth/extension with favored cell culture morphology and showed no cytotoxicity toward neural cells. The results ultimately indicated that the fabricated scaffold has potential for guiding nerve tissue growth and can be used as nerve regeneration scaffolds.

Ayurvedic processing of α-HgS gives novel physicochemistry and distinct toxicokinetics in zebrafish.

Rasasindura (RS) is an Ayurvedic medicine, which contains ∼99% α-HgS. It is used as a rejuvenating agent and commonly used to treat diseases such as syphilis, insomnia, high fever, and nervous disorders. Cinnabar ore (α-HgS) is a well-known mineral, which is readily available. Despite it, Ayurvedic practitioners adopted an involved and tedious procedure for the preparation of RS. In this study, three samples, one was Ayurvedic (RS), the second one was the commercial (HGS), and the third one was cinnabar ore (CN), were physiochemically examined. Zebrafish model was employed for toxicity study with an oral dose of 100 mg/kg/day for the three samples for 10 days. We found that RS conferred novel physicochemical properties, which were not seen in HGS and CN. Significantly, the average crystallite size of RS was lowest (26 nm) as compared to HGS (31 nm) and CN (34 nm), and the rate of increase of crystallite size with temperature was lowest in RS. RS did not show any significant behavioral toxicity in zebrafish, which was seen with the HGS-and CN-treated zebrafish. HGS-and CN-treated zebrafish showed a significantly high (∗∗∗p < 0.001) decrease (77 ± 7.6% and 51 ± 6.5%, respectively) of glutathione (GSH) levels in the brain, however, for RS-treated zebrafish, the change of GSH was insignificant (26 ± 2.5%, p > 0.05). Interestingly, HGS significantly altered the γ-aminobutyric acid (GABA) in brain tissue. Therefore, among all three samples, RS exhibited the lowest toxicity, which can be credited to the distinct toxicokinetics by these samples.

Effect of silver doping on antidiabetic and antioxidant potential of ZnO nanorods.

BACKGROUND: Increasing resistance to available drugs and their associated side-effects have drawn wide attention towards designing alternative therapeutic strategies for control of hyperglycemia and oxidative stress. The roles of the sizes and shapes of the nanomaterials used in the treatment and management of Type 2 Diabetes Mellitus (T2DM) in preventing chronic hyperglycaemia and oxidative stress are investigated. We report specifically on the effects of doping silver (Ag) into the ZnO nanorods (ZnO:Ag NR's) as a rational drug designing strategy. METHODS: Inhibition of porcine pancreatic α-amylase, murine pancreatic amylase, α-glucosidase, murine intestinal glucosidase and amyloglucosidase are checked for evaluation of antidiabetic potential. In addition, the radical scavenging activities of ZnO:Ag NR's against nitric oxide, DDPH and superoxide radicals are evaluated. RESULTS: Quantitative radical scavenging and metabolic enzyme inhibition activities of ZnO:Ag NR's at a concentration of 100 µg/mL were found to depend on the amount of Ag doped in up to a threshold level (3-4 %). Circular dichroism analysis revealed that the interaction of the NR's with the enzymes altered their secondary conformation. This alteration is the underlying mechanism for the potent enzyme inhibition. CONCLUSIONS: Enhanced inhibition of enzymes and scavenging of free radicals primarily responsible for reactive oxygen species (ROS) mediated damage, provide a strong scientific rationale for considering ZnO:Ag NR's as a candidate nanomedicine for controlling postprandial hyperglycaemia and the associated oxidative stress.