Krishna Priyadarshini Das's research while affiliated with Indian Institute of Technology Delhi and other places

Phosphorus to an optimum extent is an essential nutrient for all living organisms and its scarcity may cause food security, and environmental preservation issues vis-à-vis agroeconomic hurdles. Undesirably excess phosphorus intensifies the eutrophication problem in non-marine water bodies and disrupts the natural nutrient balance of the ecosystem. To overcome such dichotomy, biodegradable polymer–based adsorbents have emerged as a cost-effective and implementable approach in striking a “desired optimum-undesired excess” balance pertaining to phosphate in a sustainable manner. So far, the reports on adopting such adsorbent-approach for wastewater remediation remained largely scattered, unstructured, and poorly correlated. In this background, the contextual review comprehensively discusses the current state-of-the-art in utilizing biodegradable polymeric frameworks as an adsorbent system for phosphate removal and its efficient recovery from the aquatic ecosystem, while highlighting their characteristics-specific functional efficiency vis-à-vis easiness of synthetic and commercial viability. The overview further delves into the sources and environmental ramifications of excessive phosphorus in water bodies and associated mechanistic pathways of phosphorus removal via adsorption, precipitation, and membrane filtration enabled by biodegradable (natural and synthetic) polymeric substrates. Finally, functionality optimization, degradability tuning, and adsorption selectivity of biodegradable polymers are highlighted, while aiming to strike a balance in “removal-recovery-reuse” dynamics of phosphate. Thus, the current review not only paves the way for future exploration of biodegradable polymers in sustainable cost-effective adsorbents for phosphorus removal but also can serve as a guide for researchers dealing with this critical issue.

Biodegradable blends of PHB/Bio-PBS were successfully electrospun with solvent system 2,2,2-trifluoroethanol as the solvent to obtain electrospun mats (EMs) of fiber diameters ranging from 534 ± 135 to 181 ± 84 nm. The addition of CaCl2 led to defect/bead free morphology of PHB and PHB/Bio-PBS blends with the exception for Bio-PBS at ~ 20 wt% concentration. Bio-PBS based electrospun mats with CaCl2 led to the lowest fiber diameter (due to high conductivity and low viscosity of solution). Further, our study indicates that PHB/Bio-PBS blends displayed shear-thinning behavior with reduction in solution viscosity which in turn remained in tune with increasing Bio-PBS concentration. DSC studies indicated a more significant drop in crystallinity for PHB/Bio-PBS blends and as well corroborated by WAXD. Mechanical properties were affected by immiscibility, resulting in lower tensile strength from ~ 4.0 to ~ 2.0 MPa and tensile modulus from ~ 186 to ~ 64 MPa, while strain-at-break increased from ~ 1.5 to ~ 46.5% with Bio-PBS content in PHB matrix. Electrospun mats with up to 50% Bio-PBS loading demonstrated optimal ductility and strength and also exhibited a tensile modulus comparable to that of cancellous bone. Additionally, the blend with ~ 50 wt% of Bio-PBS showed increased hydrophobicity (116°) and decreased swelling characteristics (84%) compared to neat PHB (95° and 124%). Hydrolytic degradation studies showed improved structural robustness and consistent morphology in Bio-PBS based electrospun mats even after 30 days in phosphate buffer solution compared to PHB based mats. Thus, up to 50 wt% Bio-PBS incorporation into Polyhydroxyalkanoates matrices, i.e. in the blends with 50:50 composition ratio the mats obtained showed enhanced pliability in combination with the desired extent of physico-mechanical properties and stiffness for soft bone tissue engineering.

The Indian subcontinent has probably the most elevated pace of oral malignant growth on the planet. 65% of all malignant growth in men and 33% of all diseases in ladies are tobacco related. It is assessed that approximately 1,000,000 individuals die because of tobacco related illnesses in India every year. It is essential that numerous oral squamous cell carcinomas transform from conceivably harmful issues such as oral potentially malignant disorders (OPMDs). Zingiber officinale has been used since long for their mitigating properties, notwithstanding and has been used to treat inflammation as it inhibits cyclooxygenase. There is data in regards to the distinguishing proof of gingerol-related mixtures that have mitigating movement through the particular hindrance of COX-2. Our main objective was to formulate a cellulose based muccoadhesive films impregnated with small dose of zingibain for management of OPMDs to guarantee prolonged retention of the medicament on to the oral mucosa for better treatment outcome. The mucoadhesive buccal patch would not only retain the medicament for a longer period, but will also act as a muco-protective barrier for faster wound healing. The present paper would be describing the potential application of Zingibain containing mucoadhesive buccal patch for an effective non-surgical management of OPMDs.

The present study deals with the development of uniform, bead-free, and urea-loaded PVA/SA-based sustainable electrospun fibrous constructs as a controlled release fertilizer system. Taguchi L9 OA was used to predict the optimal level of control parameters i.e., urea loading (∼ 45 phr), flow rate (∼ 1 ml/h), polymeric concentration (∼ 8 wt%), and an applied voltage of ∼ 25 kV, to fabricate EMs with minimum fiber diameter (∼ 0.208 µm) and diametral variation (∼ 0.017 µm). Microstructural analysis confirmed the presence of hydrogen bonding interactions between urea and the polymer matrix, as well as successful ionic crosslinking. The contact angle and thermogravimetric analysis indicated an increase in hydrophobicity (from ∼ 30.64º to ∼ 74.13º) and thermal stability (from 164 ºC to ∼ 290 ºC) for PVA/SA-based EMs upon urea incorporation and post crosslinking, respectively. Further, the effect of urea loading and crosslinking on swelling and degradation behavior revealed a subsequent increase in water absorption capacity up to ∼ 296 % accompanied by a decrease in degradation rate up to ∼ 13%. The swelling behavior of EMs exhibited a desirably good level of pH level, salt/alkali solution sensitivity, and water retention potential lasting up to ∼16 days in soil. Spectroscopic analysis revealed a non-Fickian diffusion-induced sustained release of urea in water (> 21 days) and soil media (> 30 days). Soil burial studies of crosslinked urea-loaded EMs exhibited excellent biodegradability (> 80 % in 60 days) and structural stability (∼30 days). Thus, the study demonstrated the design of mechano-functionally engineered urea-loaded optimized PVA/SA-based EMs as potential controlled nutrient release substrates with improved and sustainable physicomechanical performance for agricultural practices.

Clean and sustainable agricultural production that is organic and minimally assisted by chemicals is one of the major challenges of the 21st century. In view of the unpredictable climatic changes, destruction of natural resources, loss of biodiversity, contamination of soil-water interfacial ecosystems due to overuse of fertilizers and pesticides, and towering food demands with a fast-multiplying population. Therefore, polymer-based electrospun micro/nanofibers and their structured assemblies offering design-versatility, manufacturing-viability, and economically efficient scalability can significantly contribute to the agrotechnological revolution and thus exhibit the imminent potential to reform the agricultural system by promoting both yield and environmental sustainability via a significant reduction in the application of chemicals. Agrochemical-based fibrous assemblies with diversified micro/nano morphological attributes can potentially boost agricultural production, leading to a paradigm shift from the conventional “sow (seeds)-throw (fertilizers)-spray (pesticides)” to smart and clean “fix-it and forget-it” approach for sustainably ensuring agro-yield, agro-practices, agro-crop quality, and agro-economy. However, the viability of the application of such functionally efficient fibrous structures in agriculture and their qualitative parametric analysis and assessments remain unexplored till date. The current analytical overview summarizes the applications of electrospun assemblies in a variety of controlled agrochemicals (such as fertilizers, pesticides, and biocontrol agents) delivery systems, seed coating, and sensors for soil and crop quality, and protective clothing's for farmers. Integrated decision-making methodologies (SWOT and TOWS) were applied to evaluate and develop effective and adaptable strategies to improve the production chain and promote environmental sustainability. The review extends further to the potential concerns associated with electrospun mats in agricultural applications along with some novel insights to address the apposite challenges so as to foster prospective designing and commercialization of innovative biodegradable and sustainable nanostructured materials for precision agriculture.

With the dream of a sustainable future, the membrane-nanomaterial composites have been the cynosure of exploitation. Owing to limitations such as fouling, instability, the trade-off between permeability and selectivity, and many more, researchers have hurdled with the noncommerciality of membrane processes. Membrane-nanomaterial composites can iron out most of these limitations, thus paving the way to commercialization. The present work emphasizes the fundamental properties of functionalized nanomaterials followed by the exploration of membranes and builds upon membrane-nanomaterial composites concepts. This work has supported the fame of the membrane-nanomaterial composites with ample information about the challenges faced by conventional membranes. Further, this work elaborates on the critical development of the theoretical concepts of membrane nanomaterial with detailed illustration on phase separation, stretching, track etching, and electrospinning membrane fabrication methods. Advanced thin-film nanocomposite membrane fabrication using dip coating and interfacial polymerization has been detailed to focus the updated nanocomposite development.

The research and development of nanostructured materials are in a period of intense growth. However, owing to the larger surface area, they are vulnerable to being influenced by the environmental changes leading to the reduction of their stability and performance. Therefore, modification of nanomaterials’ surface by embedding functional groups will be a great potential solution to overcome its major limitations. Surface functionalization tunes the interaction of surface entities, thereby allowing them to exhibit specific properties for their sustainable and emerging applications. This work illustrates the various functionalized nanomaterials implemented in the membrane technology such as carbon-based (carbon nanotube, graphene, fullerene, nanodiamond), metal-based (gold, silver, zinc oxide, titanium oxide), silica-based (silicalite, MCM-41), and polymer-based nanomaterials. It also gives an overview of different strategies enforced for designing and synthesizing functionalized nanomaterials by covalent, noncovalent, intrinsic surface, and amorphous functionalization techniques and enumerates their potential emerging applications in various fields.

The unforeseen outbreak of the COVID-19 epidemic has significantly stipulated the use of plastics to minimize the exposure and spread of the novel coronavirus. With the onset of the vaccination drive, the issue draws even more attention due to additional demand for vaccine packaging, transport, disposable syringes, and other allied devices scaling up to many million tonnes of plastic. Plastic materials in personal protective equipment (PPE), disposable pharmaceutical devices, and packaging for e-commerce facilities are perceived to be a lifesaver for the frontline healthcare personnel and the general public amidst recurring waves of the pandemic. However, the same material poses a threat as an evil environmental polluter when attributed to its indiscriminate and improper littering as well as mismanagement. The review not only highlights the environmental consequences due to the excessive use of disposable plastics amidst COVID-19 but also recommends mixed approaches to its management by adopting the combined and step-by-step methodology of adequate segregation, sterilization, sanitization activities, technological intervention, and process optimization measures. The overview finally concludes with some crucial way-forward measures and recommendations like the development of bioplastics and focusing on biodegradable/bio-compostable material alternatives to holistically deal with future pandemics. Graphical abstract