Electrocatalytic activity of BasoliteTM F300 metal-organic-framework structures

For the case of the commercially available metal-organic framework (MOF) structure BasoliteTM F300 or Fe(BTC) with BTC = benzene-1,3,5-tricarboxylate, it is shown that the Fe(III/II) electrochemistry is dominated by reductive dissolution rather than ion insertion (which in marked contrast is dominating the behaviour of Fe(III/II) open framework processes in Prussian blues). Solid Fe(BTC) immobilised onto graphite or platinum working electrodes is investigated and it is shown that well-defined and reversible Fe(III/II) reduction responses occur only on platinum and in the presence of aqueous acid. The process is shown to follow a CE-type mechanism involving liberation of Fe(III) in acidic media, in particular for high concentrations of acid. Effective electrocatalysis for the oxidation of hydroxide to O2 (anodic water splitting) is observed in alkaline aqueous media after initial cycling of the potential into the reduction potential zone. A mechanism based on a MOF-surface confined hydrous iron oxide film is proposed. Keywords: MOF, Voltammetry, Prussian blue, Reductive dissolution, Host guest electrochemistry, Water splitting, Senso

Multi-leveled Nanosilicate Implants Can Facilitate Near-Perfect Bone Healing

Several studies have shown that nanosilicate-reinforced scaffolds are suitable for bone regeneration. However, hydrogels are inherently too soft for load-bearing bone defects of critical sizes, and hard scaffolds typically do not provide a suitable three-dimensional (3D) microenvironment for cells to thrive, grow, and differentiate naturally. In this study, we bypass these long-standing challenges by fabricating a cell-free multi-level implant consisting of a porous and hard bone-like framework capable of providing load-bearing support and a softer native-like phase that has been reinforced with nanosilicates. The system was tested with rat bone marrow mesenchymal stem cells in vitro and as a cell-free system in a critical-sized rat bone defect. Overall, our combinatorial and multi-level implant design displayed remarkable osteoconductivity in vitro without differentiation factors, expressing significant levels of osteogenic markers compared to unmodified groups. Moreover, after 8 weeks of implantation, histological and immunohistochemical assays indicated that the cell-free scaffolds enhanced bone repair up to approximately 84% following a near-complete defect healing. Overall, our results suggest that the proposed nanosilicate bioceramic implant could herald a new age in the field of orthopedics.</p

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Not AvailableFood security of the country has been improved due to green revolution and enhancement of cereal production. However, recent surveys showed 35.8% of children suffer from malnutrition in India. The Indian Council of Agricultural Research has taken lead for the biofortification of cereal crops based on earlier national and international research efforts, targeting the enhancement of nutrients in staple food crops. In this article, the significant progress made in rice, wheat, maize and millets for identification of genotypes, development, evaluation and release of the varieties with high nutrient contents and their bioavailability studies is discussed.Not Availabl

Biofortification in cereals: progress and prospects

Not AvailableATTAINMENT of self sufficiency in food grains at national level, especially cereals, is one of the major achievements of the green revolution during mid-sixties in India. The nation’s food grains production increased markedly from 50.82 million tonnes in 1950–51 to 252.22 million tonnes during 2015–16, and a similar trend has been reported in the production of food grains since the past decade1 . Despite increased production of food grains, the 2016- Global Hunger Index (GHI) Report ranked India as 9th comprising 25% of world’s hungry population amongst the top 118 countries2 . According to Rapid Survey on Children (2013–14) conducted by the Ministry of Women and Child Development, New Delhi, about 18.6% of new borns, 34.6% of children up to 3 years and 62.5% of adolescent girls suffer from malnutrition3 (Figure 1). Food deficiency disorders directly affect the health of an individual and indirectly the economy of the nation by increasing the number of Disability-Adjusted Life Years (DALYs – a framework, which quantifies the economic impact of disability and disease)4 . According to the World Bank–South Asia report, micronutrient deficiencies are responsible for losses amounting to $2.5 billion in India every year. The Government of India has made several interventions to address malnutrition; however, the incidence of malnutrition among women and children remains severe. The issue of malnutrition in the country is compounded not only by access to food, but also by social and cultural issues. Conventional strategies to combat malnutrition include dietary supplements and food fortification programmes. Efforts are now being made to fortify rice and wheat flour for iron (Fe), vitamin B12 and folic acid5 . Some of the constraints with these interventions include poor dissemination to the target population especially those residing in rural areas; sustaining them over a period of time and addressing the symptoms rather than the cause of the problem. Dietary diversification is the ideal solution to alleviate malnutrition but not viable in the Indian situation considering the inadequate purchasing power of the poor people. Thus, the long-term solution lies in increasing the essential nutrient contents of the staple food crops, viz. cereals through crop biofortification strategy.Not Availabl

Pectin Methacrylate (PEMA) and Gelatin-Based Hydrogels for Cell Delivery: Converting Waste Materials into Biomaterials

The emergence of nontoxic, eco-friendly, and biocompatible polymers derived from natural sources has added a new and exciting dimension to the development of low-cost and scalable biomaterials for tissue engineering applications. Here, we have developed a mechanically strong and durable hydrogel composed of an eco-friendly biopolymer that exists within the cell walls of fruits and plants. Its trade name is pectin, and it bears many similarities with natural polysaccharides in the native extracellular matrix. Specifically, we have employed a new pathway to transform pectin into a ultraviolet (UV)-cross-linkable pectin methacrylate (PEMA) polymer. To endow this hydrogel matrix with cell differentiation and cell spreading properties, we have also incorporated thiolated gelatin into the system. Notably, we were able to fine-tune the compressive modulus of this hydrogel in the range ∼0.5 to ∼24 kPa: advantageously, our results demonstrated that the hydrogels can support growth and viability for a wide range of three-dimensionally (3D) encapsulated cells that include muscle progenitor (C2C12), neural progenitor (PC12), and human mesenchymal stem cells (hMSCs). Our results also indicate that PEMA-gelatin-encapsulated hMSCs can facilitate the formation of bonelike apatite after 5 weeks in culture. Finally, we have demonstrated that PEMA-gelatin can yield micropatterned cell-laden 3D constructs through UV light-assisted lithography. The simplicity, scalability, processability, tunability, bioactivity, and low-cost features of this new hydrogel system highlight its potential as a stem cell carrier that is capable of bridging the gap between clinic and laboratory

AIE-featured tetraphenylethylene nanoarchitectures in biomedical application: Bioimaging, drug delivery and disease treatment

The development of aggregation-induced emission (AIE) has received extreme considerations from basic and clinical researches. To date, various luminogens with AIE property (AIEgens) have been broadly utilized in optoelectronic devices, fluorescent bio-probes, drug delivery, anticancer and chemosensors and many more. Scientists have likewise dedicated to investigating the possibilities of AIEgens in the biomedical field. Among the various AIE luminophores studied, tetraphenylethylene (TPE) derivatives have demonstrated as most promising AIEgen, owing to their capacity in self-organization and conjugation with aggregation-caused quenching (ACQ) fluorophores to form larger multi-component assemblies. It likewise generally utilized in different fields, like organic and therapeutic science, supramolecular chemistry, organic electronics, cancer therapy, apoptosis and inflammation, microorganism imaging therapy etc. This review encompasses the recent advances of TPE based AIE-active luminophores and their potential applications in biomolecular science. (C) 2021 The Authors. Published by Elsevier B.V

Combinatorial Screening of Nanoclay-Reinforced Hydrogels: A Glimpse of the "Holy Grail" in Orthopedic Stem Cell Therapy?

Despite the promise of hydrogel-based stem cell therapies in orthopedics, a significant need still exists for the development of injectable microenvironments capable of utilizing the  regenerative potential of donor cells. Indeed, the quest for biomaterials that can direct stem cells into bone without the need of external factors has been the “Holy Grail” in orthopedic stem cell therapy for decades. To address this challenge, we have utilized a combinatorial approach to screen over 63 nanoengineered hydrogels made from alginate, hyaluronic acid, and two-dimensional nanoclays. Out of these combinations, we have identified a biomaterial that can promote osteogenesis in the absence of well-established differentiation factors such as bone morphogenetic protein 2 (BMP2) or dexamethasone. Notably, in our “hit” formulations we observed a 36-fold increase in alkaline phosphate (ALP) activity and a 11-fold increase in the formation of mineralized matrix, compared to the control hydrogel. This induced osteogenesis was further supported by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy. Additionally, the Montmorillonite-reinforced hydrogels exhibited high osteointegration as evident from the relatively stronger adhesion to the bone explants as compared to the control. Overall, our results demonstrate the capability of combinatorial and nanoengineered biomaterials to induce bone regeneration through osteoinduction of stem cells in a natural and differentiation-factor-free environment