Carbon nanotubes (CNTs), the most promising material with unique characteristics, find its application in different fields ranging from composite materials to medicine and from electronics to energy storage. However, little is known about the mechanism behind the interaction of these particles with cells and their toxicity. So, here we investigated the adverse effects of multiwalled CNTs (MWCNTs) in rat lung epithelial (LE) cells. The results showed that the incubation of LE cells with 0.5-10 microg/mL of MWCNTs caused a dose- and time-dependent increase in the formation of free radicals, the accumulation of peroxidative products, the loss of cell viability, and antioxidant depletion. The significant amount of incorporation of dUTPs in the nucleus after 24 h confirms the induction of apoptosis. It was also observed that there is an increase in the activity of both caspases-3 and caspase-8 in cells, with increases in time and the concentration of MWCNTs. No significant incorporation of dUTPs was observed in cells, incubated with z-VAD-fmk, which confirmed the role of caspases in DNA fragmentation. The present study reveals that MWCNTs induced oxidative stress and stimulated apoptosis signaling pathway through caspase activation in rat LE cell lines.

Natural wound healing is a highly complex and regulated process. Disruption and barriers to cellular and tissue repair processes contributes to impaired wound healing, including sustained infections. Superficial wound healing requires many factors to work in concrete at the wound site, and thus many treatment options and wound dressings have evolved to address the barriers to wound healing. Biomaterials are proven to encourage the wound healing process by stimulating repair and regeneration of injured tissues and preventing wound infections. A wide range of natural and synthetic hydrophilic and porous formulations such as foams, films, fibers, and hydrogels have been examined for these applications. Among these formulations, polymeric hydrogels have gained considerable interest in the medical applications. They effectively absorb wound exudates and provide a moist environment for aiding the wound healing process. However, chronic wounds that are sustained longer might need supplementary healing features as addendums such as antimicrobials, stem cells, growth factors, peptides, vitamins, and natural compounds. Therefore, when combined with hydrogels healing supporting addendums promote rapid and effective wound healing. Although there have been several advancements in biopolymer-based hydrogel systems, only limited reviews on various management strategies in wound healing are available in medical research and applications.Therefore, in this review, we have compiled and integrated various hydrogel-based approaches with the potential to improve chronic wound healing and advance important outcomes. In addition, in-situ injectable hydrogel preparation that have the advantage of packing patient wounds of different sizes and using 3D printing based tailor-made hydrogels, and bio-inks for wound closure applications are also highlighted.

Uranium is a naturally occurring radioactive material present everywhere in the environment. It is toxic because of its chemical or radioactive properties. Uranium enters environment mainly from mines and industry and cause threat to human health by accumulating in lungs as a result of inhalation. In our previous study, we have shown the effectiveness of antioxidant system response to the oxidative stress induced by uranyl acetate (UA) in rat lung epithelial (LE) cells. As part of our continuing studies; here, we investigated the mechanism underlying when LE cells are exposed to different concentration of UA. Oxidative stress may lead to apoptotic signaling pathways. LE cells NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript treated with 0.25, 0.5 and 1 mM of UA results in dose and time-dependent increase in activity of both caspases-3 and -8. Increase in the concentration of cytochrome-c oxidase in cytosol was seen in LE cells treated with 1 mM UA as a result of mitochondria membrane permeability. The cytochrome-c leakage may trigger the apoptotic pathway. TUNEL assay performed in LE cells treated with 1 mM of UA showed significant incorporation of dNTPs in the nucleus after 24 h. In the presence of the caspase inhibitors, we observed the significant decrease in the activity of caspases-8 and -3 in 0.5 and 1 mM UA-treated LE cells.

Microgravity is known to have significant effect on all aspects of reproductive function in animal models. Recent studies have also shown that microgravity induces changes at the cellular level, including apoptosis. Our effort here was to study the effect of simulated microgravity on caspase-8 and the caspase-3 activities, the effectors of the apoptotic pathway and on the transcription factor NF-kappaB a signaling molecule in mouse testis. Morey-Holton hind limb suspension model was used to simulate microgravity. Caspase-8 and 3 fluorometric assays were carried out and HLS mice testis exhibited a 51% increase in caspase-8 and caspase-3 compared to the controls. A sandwich ELISA-based immunoassay was carried out for detection of NF-kappaB which again significantly increased in the test mice. Testosterone levels were measured using an ELISA kit and in HLS mice the decrease was significant. There was also a significant decrease in testis weight in the test mice. Simulated microgravity activates caspase 8, 3 and NF-kappaB necessary to stimulate the apoptotic pathway in mice testis. This may account for the drop in testis weight and testosterone level further affecting testicular physiology and function.

The polymicrobial biofilm of C. albicans with E. coli exhibits a dynamic interspecies interaction and is refractory to conventional antimicrobials. In this study, a high biofilm-forming multidrug-resistant strain of C. albicans overcomes inhibition by E. coli in a 24 h coculture. However, following treatment with whole Aqueous Garlic Extract (AGE), these individual biofilms of multidrug-resistant C. albicans M-207 and Ampicillin-resistant Escherichia coli ATCC 39936 and their polymicrobial biofilm were prevented, as evidenced by biochemical and structural characterization. This study advances the antimicrobial potential of AGE to inhibit drug-resistant C. albicans and bacterial-associated polymicrobial biofilms, suggesting the potential for effective combinatorial and synergistic antimicrobial designs with minimal side effects.

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FIGURE 7.With reference to our paper published in "Journal of Biochemical and Molecular Toxicology" entitled "Induction of apoptosisin rat lung epithelial cells by multiwalled carbon nanotubes".

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