Anti-inflammatory and anti-arthritic potential of Coagulansin-A: in vitro and in vivo studies.

The current work was designed to evaluate the anti-inflammatory and anti-arthritic potential of Coagulansin-A (Coag-A) using mouse macrophages and arthritic mice. In the LPS-induced RAW 264.7 cells, the effects of Coag-A on the release of nitric oxide (NO), reactive oxygen species (ROS), and pro-inflammatory cytokines were analyzed. In addition, the mediators involved in the nuclear factor-kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) pathways were evaluated by the RT-qPCR and western blotting. Coag-A did not show significant cytotoxicity in the RAW 264.7 cells in the tested concentration range (1-100 µM). Coag-A significantly inhibited the production of NO, ROS, and key pro-inflammatory cytokines. The anti-inflammatory effects of Coag-A might be through inhibiting the NF-κB pathway and activating the Nrf2 pathway. In the arthritic mouse models, behavioral studies and radiological and histological analyses were performed. We found that the i.p. injection of Coag-A dose-dependently (1-10 mg/kg) reduced the Carrageenan-induced acute inflammation in the mice. In Complete Freund's Reagent-induced arthritic mouse model, Coag-A (10 mg/kg) showed significant anti-inflammatory and anti-arthritic effects in terms of the arthritic index, hematological parameters, and synovium inflammation. After the Coag-A treatment, the bone and tissue damage was ameliorated significantly in the arthritic mice. Moreover, immunohistochemistry of mouse paw tissues revealed a significant reduction in the expression of pro-inflammatory cytokines in the NF-κB pathway, confirming Coag-A's therapeutic potential and mechanism.

Halloysite nanoclay reinforced hydroxyapatite porous scaffold for hard tissue regeneration.

Hydroxyapatite (HAP), a natural constituent of bone tissue is commonly used for the clinical treatment of bone defects due to its similar structure with bone and excellent biocompatibility. However, the processing exertion, poor osteoinductive capability and poor mechanical strength of HAP needs further addressing for its immense implementation in tissue engineering. Different approaches have been reported to escalate the mechanical hardness and osteogenic potential of HAP. In the present work, halloysite nanoclay (HNC) and sericin protein were used for better mechanical and osteogenic properties, respectively. Halloysite nanoclay (HNC, 1.0-4.0%) was used to reinforce hydroxyapatite (HAP) and the mechanical strength of nanocomposite scaffolds were evaluated. After surface modification of nanocomposite scaffolds with 1.0% silk sericin protein; physical properties like microstructure, porosity, swelling ratio and degradation rate were evaluated. Cell morphology, cytocompatibility and alkaline phosphatase (ALP) activity were assessed using MG 63 osteoblast cell lines. HAP reinforced with 4% HNC (HAP@4) showed a significant increase (199 MPa) in young modulus as compared to pure HAP. HAP reinforced with 2% HNC (HAP@2) and 4% HNC (HAP@4) showed a significant decrease in porosity as well as degradation rate than pure HAP but no significant difference was observed in swelling ratio. The scanning electron microscope (SEM) images of the scaffolds showed porous architecture. Remarkably, the incorporation of HNC in HAP enhanced the cytocompatibility as well as ALP activity in comparison to pure HAP. Overall, these results suggested that halloysite nanoclay reinforced HAP scaffold could be an auspicious alternative for bone tissue regeneration.

SERS based rapid and ultrasensitive detection of Japanese Encephalitis Virus.

Japanese encephalitis (JE) is a mosquito-borne flavivirus infection named Japanese Encephalitis Virus (JEV), prevalent in Asia-pacific countries, requires an accurate and rapid diagnosis to contain the outbreak of the disease. In cases of low viral load in early-stage infections, this task becomes difficult. Therefore, we have developed a surface-enhanced Raman spectroscopy (SERS) based biosensor for rapid, sensitive, and early-stage detection of JE antigen. In this work, silver nanoparticles were deposited over a glass coverslip and used as a substrate for designing the sensing platform. Silver Nanoparticles have good metallic properties and plasmon activity. Therefore, it amplifies the Raman signals and provides a suitable surface for the SERS substrate. The developed platform has been used for the detection of the Japanese encephalitis virus (JEV). The fabricated sensor shows a linear response from 5 ng/mL to 80 ng/mL with a limit of detection (LoD) of ∼7.6 ng/mL. Therefore, this method could be a significant addition to the diagnostic modalities for early, sensitive, and specific diagnoses of JE antigen even at the nanogram level.

Enhanced Osteogenesis by Molybdenum Disulfide Nanosheet Reinforced Hydroxyapatite Nanocomposite Scaffolds.

The advances in the arena of biomedical engineering enable us to fabricate novel biomaterials that provide a suitable platform for rapid bone regeneration. Herein, we have investigated the in vitro and in vivo osteogenic differentiation, proliferation, and bone regeneration capability of molybdenum disulfide nanosheets (MoS2NSs) reinforced HAP nanocomposite scaffolds. The MG-63 cells were incubated with HAP and HAP/MoS2NSs nanocomposite and followed for various cellular activities. The cells incubated with HAP@2 shows higher cell adhesion, cell proliferation, and alkaline phosphatase activity (ALP) in contrast to HAP. The in vivo and in vitro results of the increased ALP level confirm that HAP@2 promotes osteogenic differentiation. This improved osteogenesis was validated with upregulation of osteogenic marker viz. transcription factor, RUNX-2 (∼34 fold), collagen-1 (∼15 fold), osteopontin (∼11 fold), osteocalcin (∼20 fold), and bone morphogenetic protein-2 (∼12 fold) after 12 week postimplantation in comparison to drilled. The X-ray imaging demonstrates that HAP@2 implants promote rapid osteogenesis and bioresorbability than HAP and drilled. The outcomes of the present study provide a promising tool for the regeneration of bone deformities, without using any external growth factor.

Nitrogen doped carbon quantum dots demonstrate no toxicity under in vitro conditions in a cervical cell line and in vivo in Swiss albino mice.

Carbon quantum dots (CQDs) and their derivatives have potential applications in the field of biomedical imaging. Toxicity is one of the critical parameters that can hamper their success in biological applications. In this context, our goal was to systematically investigate both in vivo and in vitro toxicity of nitrogen doped carbon quantum dots (NCQDs). In vivo toxic effects were evaluated for 30 days in Swiss albino mice at two different concentrations (5.0 mg per kg body weight (BW) and 10.0 mg per kg BW) of NCQDs. Results of haematological, serum biochemical, antioxidant and histopathological parameters showed no noteworthy defects at both of these concentrations. An in vitro assessment was performed against the human cervical cancer cell line (HeLa cells) at the concentration of 0-400 µg ml-1. The LDH profile, DNA fragmentation, apoptosis, and growth cycle of cells showed no apparent toxicity of NCQDs. The overall study offers highly biocompatible N-doped carbon quantum dots, which may be considered as an attractive material for future biomedical applications.

Partially reduced graphene oxide-gold nanorods composite based bioelectrode of improved sensing performance.

The present work proposes partially reduced graphene oxide-gold nanorods supported by chitosan (CH-prGO-AuNRs) as a potential bioelectrode material for enhanced glucose sensing. Developed on ITO substrate by immobilizing glucose oxidase on CH-prGO-AuNRs composite, these CH-prGO-AuNRs/ITO bioelectrodes demonstrate high sensitivity of 3.2 µA/(mg/dL)/cm(2) and linear range of 25-200 mg/dL with an ability to detect as low as 14.5 mg/dL. Further, these CH-prGO-AuNRs/ITO based electrodes attest synergistiacally enhanced sensing properties when compared to simple graphene oxide based CH-GO/ITO electrode. This is evident from one order higher electron transfer rate constant (Ks) value in case of CH-prGO-AuNRs modified electrode (12.4×10(-2) cm/s), in contrast to CH-GO/ITO electrode (6×10(-3) cm/s). Additionally, very low Km value [15.4 mg/dL(0.85 mM)] ensures better binding affinity of enzyme to substrate which is desirable for good biosensor stability and resistance to environmental interferences. Hence, with better loading capacity, kinetics and stability, the proposed CH-prGO-AuNRs composite shows tremendous potential to detect several bio-analytes in the coming future.