Zinc oxide nanoparticles (ZnO-NPs) have wide biological applications, which has raised serious concerns about their impact on the health and environment. Although, various studies have shown ZnO-NP toxicity on different cells under in vitro conditions, sufficient information is lacking regarding toxicity and underlying mechanisms under in vivo conditions. In this work, we investigated genotoxic, clastogenic and cytotoxic effects of ZnO-NPs on macrophages and in adult mice. ZnO-NP treated mice showed signs of toxicity such as loss in body weight, passive behaviour and reduced survival. Further mechanistic studies revealed that administration of higher dose caused severe DNA damage in peripheral blood and bone marrow cells as evident by the formation of COMET tail, micronuclei, chromosomal fragmentation and phosphorylation of H2A histone family member X. Moreover, ZnO-NPs inhibited DNA repair mechanism by downregulating the expression of fen-1 and polB proteins. Histopathological examinations showed severe inflammation and damage to liver, lungs and kidneys. Cell viability and wound healing assays revealed that ZnO-NPs killed macrophages in a dose-dependent manner, caused severe wounds and inhibited cellular migration by irreversible actin depolymerization and degradation. Reduction in the viability of macrophages was due to the arrest of the cell cycle at the G0/G1 phase, inhibition of superoxide dismutase and catalase and eventually reactive oxygen species. Furthermore, treatment with an antioxidant drug N-acetyl cysteine significantly reduced the ZnO-NP induced genotoxicity both in vitro and in vivo. Altogether, this study gives detailed pathological insights of ZnO-NP that impair cellular functions, thus will enable to arbitrate their biological applications.

We report a porous thiazolo[5,4- d ]thiazole-bridged porphyrin organic framework, Por-TzTz-POF, with promising nonlinear optical (NLO) activity.

Harvesting mechanical energy from the surroundings can be a promising power source for micro/nano-devices. The triboelectric nanogenerator (TENG) works on the principle of triboelectrification and electrostatic induction. So far, metals and polymers have mostly dominated the conventional triboelectric series, but there is a need to find novel materials to extend the triboelectric series and further improve the performance of a TENG. Herein, a zeolitic imidazole framework (ZIF-67) was synthesized using a room temperature solvent-assisted route. Extensive material analysis was performed to understand its structural and chemical properties. Further, a simple vertical contact mode S-shaped TENG device (abbreviated further as S-TENG) was fabricated using an additive manufacturing approach. ZIF-67 acted as a positive triboelectric layer while Teflon/PDMS acted as a negative triboelectric layer. The multi-unit S-TENG device was further utilized for self-powered recognition of the various gaits using a digital signal processing approach. The S-TENG device based on ZIF-67 and Teflon produced a voltage of 118 V, a current of 1.7 μA, and a power density of 15 μW cm² at a load resistance of 50 MΩ. The gait analysis of different volunteers was recorded by employing the S-TENG device and the digital signal processing route to effectively distinguish the gait patterns for the prevention of falls and injury. The S-TENG device was utilized to charge a commercial capacitor for powering a wristwatch and further it was attached to a robotic gripper for object identification.

In this report, we present a simple, swift mechanochemical synthesis of metal–organic frameworks (MOFs) using a kitchen grinder. By adopting this tool, we could synthesize ZIF-8, CuBTC, and MIL-100(Fe) in multi gram-scale and successfully employ MIL-100(Fe)-KG for the efficient (ca. 98%) removal of an organic dye (methylene blue) from aqueous solution. In particular, we demonstrated the significance of pore aperture for effective dye adsorption by comparing the adsorption behaviours of ZIF-8-KG and MIL-100(Fe)-KG. We believe that this approach could be of economic interest towards the green synthesis of porous adsorbents for waste-water treatment.

In order to improve the chemotherapy of tuberculosis, there is an urgent need to enhance the efficacy of existing agents and also to develop more efficient drug delivery systems. Here, we synthesized a novel anti-TB drug complex consisting of zinc and rifampicin (Zn-RIF) and encapsulated it into transferrin-conjugated silver quantum-dots (Zn-RIF-Tf-QD) to improve delivery in macrophages. Successful synthesis of Zn-RIF and Zn-RIF-Tf-QD was confirmed by UV/Vis-spectroscopy, TEM, FTIR, photoluminescence, XRD, XPS and NMR. The sizes of silver QDs and transferrin-conjugated QDs were found to be in the range of 5–20 nm. Activity assays showed that Zn-RIF-Tf-QD exhibited 10-fold higher antibacterial activity against Mycobacterium smegmatis and Mycobacterium bovis-BCG as compared to Zn-RIF, RIF and Zn. Immunofluorescence studies showed that Zn-RIF-Tf-QD-conjugates were actively endocytosed by macrophages and dendritic cells, but not by lung epithelial cells. Treatment with Zn-RIF-Tf-QD efficiently killed mycobacteria residing inside macrophages without exhibiting cytotoxicity and genotoxicity. Moreover, the conjugates remained stable for upto 48 h, were taken up into the late endosomal compartment of macrophages and released the drug in a sustainable manner. Our data demonstrate that Zn-RIF-Tf-QDs have a great potential as anti-TB drugs. In addition, transferrin-conjugated QDs may constitute an effective drug delivery system for tuberculosis therapy.