Chitosan-based aerogels: A new paradigm of advanced green materials for remediation of contaminated water.

Chitosan (CS) aerogels are highly porous (∼99 %), exhibit ultralow density, and are excellent sorbents for removing ionic pollutants and oils/organic solvents from water. Their abundant hydroxyl and amino groups facilitate the adsorption of ionic pollutants through electrostatic interaction, complexation and chelation mechanisms. Selection of suitable surface wettability is the way to separate oils/organic solvents from water. This review summarizes the most recent developments in improving the adsorption performance, mechanical strength and regeneration of CS aerogels. The structure of the paper follows the extraction of chitosan, preparation and sorption characteristics of CS aerogels for heavy metal ions, organic dyes, and oils/organic solvents, sequentially. A detailed analysis of the parameters that influence the adsorption/absorption performance of CS aerogels is carried out and their effective control for improving the performance is suggested. The analysis of research outcomes of the recently published data came up with some interesting facts that the unidirectional pore structure and characteristics of the functional group of the aerogel and pH of the adsorbate have led to the enhanced adsorption performance of the CS aerogel. Finally, the excerpts of the literature survey highlighting the difficulties and potential of CS aerogels for water remediation are proposed.

Exploring the Potential of Sustainable Biopolymers as a Shield against Electromagnetic Radiations.

The increasing demand for biodegradable and environmentally friendly materials is shifting the focus from traditional polymer composites to biocomposites in various applications, especially in electromagnetic shielding. Effective utilization of biopolymers demands improved properties and can be achieved to a certain extent by functionalization. Biopolymers such as cellulose, polylactic acid, and starch are some of the potential candidates for mitigating electromagnetic pollution in next-generation electronic devices because of their high aspect ratio, flexibility, light weight, high mechanical strength, thermal stability, and tunable microwave absorption to the electromagnetic interference (EMI) shielding composites. This Review provides an overview of the current advancements in EMI shielding materials and outlines recent research on EMI shielding composites that utilize various biodegradable polymer structures.

Emerging Biohybrids of Aptamer-Based Nano-Biosensing Technologies for Effective Early Cancer Detection.

Cancer is a leading global cause of mortality, which underscores the imperative of early detection for improved patient outcomes. Biorecognition molecules, especially aptamers, have emerged as highly effective tools for early and accurate cancer cell identification. Aptamers, with superior versatility in synthesis and modification, offer enhanced binding specificity and stability compared with conventional antibodies. Hence, this article reviews diagnostic strategies employing aptamer-based biohybrid nano-biosensing technologies, focusing on their utility in detecting cancer biomarkers and abnormal cells. Recent developments include the synthesis of nano-aptamers using diverse nanomaterials, such as metallic nanoparticles, metal oxide nanoparticles, carbon-derived substances, and biohybrid nanostructures. The integration of these nanomaterials with aptamers significantly enhances sensitivity and specificity, promising innovative and efficient approaches for cancer diagnosis. This convergence of nanotechnology with aptamer research holds the potential to revolutionize cancer treatment through rapid, accurate, and non-invasive diagnostic methods.

Chitosan-based electroconductive inks without chemical reaction for cost-effective and versatile 3D printing for electromagnetic interference (EMI) shielding and strain-sensing applications.

The burgeoning interest in biopolymer 3D printing arises from its capacity to meticulously engineer tailored, intricate structures, driven by the intrinsic benefits of biopolymers-renewability, chemical functionality, and biosafety. Nevertheless, the accessibility of economical and versatile 3D-printable biopolymer-based inks remains highly constrained. This study introduces an electroconductive ink for direct-ink-writing (DIW) 3D printing, distinguished by its straightforward preparation and commendable printability and material properties. The ink relies on chitosan as a binder, carbon fibers (CF) a low-cost electroactive filler, and silk fibroin (SF) a structural stabilizer. Freeform 3D printing manifests designated patterns of electroconductive strips embedded in an elastomer, actualizing effective strain sensors. The ink's high printability is demonstrated by printing complex geometries with porous, hollow, and overhanging structures without chemical or photoinitiated reactions or support baths. The composite is lightweight (density 0.29 ± 0.01 g/cm3), electroconductive (2.64 ± 0.06 S/cm), and inexpensive (20 USD/kg), with tensile strength of 20.77 ± 0.60 MPa and Young's modulus of 3.92 ± 0.06 GPa. 3D-printed structures exhibited outstanding electromagnetic interference (EMI) shielding effectiveness of 30-31 dB, with shielding of >99.9 % incident electromagnetic waves, showcasing significant electronic application potential. Thus, this study presents a novel, easily prepared, and highly effective biopolymer-based ink poised to advance the landscape of 3D printing technologies.

Comprehensive review on recent trends and perspectives of natural exo-polysaccharides: Pioneering nano-biotechnological tools.

Exopolysaccharides (EPSs), originating from various microbes, and mushrooms, excel in their conventional role in bioremediation to showcase diverse applications emphasizing nanobiotechnology including nano-drug carriers, nano-excipients, medication and/or cell encapsulation, gene delivery, tissue engineering, diagnostics, and associated treatments. Acknowledged for contributions to adsorption, nutrition, and biomedicine, EPSs are emerging as appealing alternatives to traditional polymers, for biodegradability and biocompatibility. This article shifts away from the conventional utility to delve deeply into the expansive landscape of EPS applications, particularly highlighting their integration into cutting-edge nanobiotechnological methods. Exploring EPS synthesis, extraction, composition, and properties, the discussion emphasizes their structural diversity with molecular weight and heteropolymer compositions. Their role as raw materials for value-added products takes center stage, with critical insights into recent applications in nanobiotechnology. The multifaceted potential, biological relevance, and commercial applicability of EPSs in contemporary research and industry align with the nanotechnological advancements coupled with biotechnological nano-cleansing agents are highlighted. EPS-based nanostructures for biological applications have a bright future ahead of them. Providing crucial information for present and future practices, this review sheds light on how eco-friendly EPSs derived from microbial biomass of terrestrial and aquatic environments can be used to better understand contemporary nanobiotechnology for the benefit of society.

Nanocellulose-Based Hybrid Scaffolds for Skin and Bone Tissue Engineering: A 10-Year Overview.

Cellulose, the most abundant polymer on Earth, has been widely utilized in its nanoform due to its excellent properties, finding applications across various scientific fields. As the demand for nanocellulose continues to rise and its ease of use becomes apparent, there has been a significant increase in research publications centered on this biomaterial. Nanocellulose, in its different forms, has shown tremendous promise as a tissue engineered scaffold for regeneration and repair. Particularly, nanocellulose-based composites and scaffolds have emerged as highly demanding materials for both soft and hard tissue engineering. Medical practitioners have traditionally relied on collagen and its analogue, gelatin, for treating tissue damage. However, the limited mechanical strength of these biopolymers restricts their direct use in various applications. This issue can be overcome by making hybrids of these biopolymers with nanocellulose. This review presents a comprehensive analysis of the recent and most relevant publications focusing on hybrid composites of collagen and gelatin with a specific emphasis on their combination with nanocellulose. While bone and skin tissue engineering represents two areas where a majority of researchers are concentrating their efforts, this review highlights the use of nanocellulose-based hybrids in these contexts.

Recent Advances of carbon Pathways for Sustainable Environment development.

Carbon dots (CDs) are an emerging type of carbon nanomaterial with strong biocompatibility, distinct chemical and physical properties, and low toxicity. CDs may emit fluorescence in the ultraviolet (UV) to near-infrared (NIR) range, which renders them beneficial for biomedical applications. CDs are usually made from carbon precursors and can be synthesized using top-down and bottom-up methods and it can be easily functionalized using different methods. For specific cases of biomedical applications carbon dot functionalization augments the materials' characteristics. Novel functionalization techniques are still being investigated. This review will look at the benefits of functionalization to attain a high yield and various biological applications. Biomedical applications such as photodynamic and photothermal therapy, biosensing, bioimaging, and antiviral and antibacterial properties will be covered in this review. The future applications of green synthesized carbon dots will be determined in part by this review.

Introduction to Bionanocomposites.

Sabu Thomas, Maya John and Aji Mathew introduce the Nanoscale Advances themed issue on Bionanocomposites.

Cold Plasma Technology Based Eco-Friendly Food Packaging Biomaterials.

Biopolymers have intrinsic drawbacks compared to traditional plastics, such as hydrophilicity, poor thermo-mechanical behaviours, and barrier characteristics. Therefore, biopolymers or their film modifications offer a chance to create packaging materials with specified properties. Cold atmospheric plasma (CAP) or Low temperature plasma (LTP) has a wide range of applications and has recently been used in the food industry as a potent tool for non-thermal food processing. Though its original purpose was to boost polymer surface energy for better adherence and printability, it has since become an effective technique for surface decontamination of food items and food packaging materials. These revolutionary innovative food processing methods enable the balance between the economic constraints and higher quality while ensuring food stability and minimal processing. For CAP to be considered as a viable alternative food processing technology, it must positively affect food quality. Food products may have their desired functional qualities by adjusting the conditions for cold plasma formation. Cold plasma is a non-thermal method that has little effects on the treated materials and is safe for the environment. In this review, we focus on recent cold plasma advances on various food matrices derived from plants and animals with the aim of highlighting potential applications, ongoing research, and market trends.

Multi-vesicular Liposome and its Applications: A Novel Chemically Modified Approach for Drug Delivery Application.

BACKGROUND: This study aimed to elaborate on all the aspects of multivesicular liposomes, including structure, function, topology, etc. Liposomes are a unique drug delivery system, in which both hydrophilic and hydrophobic drug molecules can be incorporated. Particularly, multivesicular liposomes have more advantages than other liposomes because of their unique structure. This study provides an overview of several works already performed by various researchers in this field. Numerous studies have reported on preparing and evaluating multivesicular liposomes for drug delivery applications. This study summarizes the process of formulating multivesicular liposomes and their application in drug delivery systems and provides details about how to resolve the problem of limited solubility and stability of biomolecules, along with controlled drug release kinetics, with the possibility of loading various drugs. There is no doubt that multivesicular liposome opens new avenues to develop novel drug delivery system for achieving the desired functional performances and expanding the applications in the drug delivery area.

Modified Polyethylene Foams for Insulation Systems.

Effective insulation of buildings and other industrial objects requires the use of materials and system solutions that ensure maximum uniformity and density of insulation shells. The study focuses on the development of insulation systems based on expanded polyethylene and, in particular, on the development of modified polyethylene with reduced flammability containing a flame-retardant modified montmorillonite clay, which does not hinder gas formation, and silicate nanofillers in layered construction. Active experiments based on mathematical design methods allowed us to establish an analytical relationship between flame-retardant and modifier consumption and extruder pressure and response functions: average density of polyethylene foam and flammability criterion. The flammability criterion was taken as the oxygen index of the modified polyethylene foam. A foaming agent masterbatch was used as the flame retardant. Analytical optimization of mathematical models obtained as a result of active experiments allowed us to determine the optimal flame-retardant consumption, which was 3.7-3.8% of the polymer mass. Optimised systems for average density and oxygen index of flammability of modified polyethylene were obtained. A nomogram for predicting the material properties and selecting the composition, and an algorithm for a computer program for evaluating the properties of modified polyethylene foam as a function of the values of various factors, were developed. Taking into account the possible expansion of the scope of application of rolled polyethylene foam and seamless insulation shells based on it, possible solutions for insulation systems were studied using the program THERM, and a combined insulation system was adopted.

A Novel Brevinin2 HYba5 Peptide against Polymicrobial Biofilm of Staphylococcus aureus and Enterococcus faecalis.

BACKGROUND: Brevinin2 HYba5 (Peptide 29) is a novel cationic peptide identified from an endemic frog, Hydrophylax bahuvistara. Staphylococcus aureus and Enterococcus faecalis are troublesome biofilm-forming pathogens associated with nosocomial and community-acquired infections and contribute to the severity of infections associated with implanted devices and chronic wounds. Co-existence of both pathogens in biofilm mode contributes to an increased antibiotic resistance, treatment failure and hence persistent disease burden. Identifying a novel and stable, less toxic compound targeting multispecies biofilm with a lower probability of acquiring resistance in comparison to antibiotics is highly warranted. OBJECTIVE: Evaluate the activity of Brevinin2 HYba5 against S. aureus and E. faecalis mixed biofilm. METHODS: The anti-biofilm activity of peptide 29 was tested by Crystal violet assay, Confocal laser scanning Microscopy (CLSM) and MTT Assay. Cytotoxicity of the peptide was tested in RBC and L929 fibroblast cell line. Biofilm inhibitory activity of the peptide was evaluated at different temperatures, pH, serum and plasma concentrations. The antibiofilm potential of the peptide was tested against polymicrobial biofilm by Fluorescent in situ hybridisation (FISH) and plate counting on HiCromeTM UTI Agar media. RESULTS: The peptide 29 could inhibit biofilm formation of S. aureus and E. faecalis individually as well as in polymicrobial biofilm at 75 µM concentration. The peptide maintained its antibiofilm potential at different temperatures, serum and plasma concentrations. Activity of the peptide was high at acidic and neutral pH but found to get reduced towards alkaline pH. The peptide is nonhemolytic and does not exhibit significant cytotoxicity against the L929 fibroblast cell line (92.80% cell viability). CONCLUSION: The biofilm inhibition property makes peptide 29 a promising candidate for the management of S. aureus and E. faecalis biofilm, especially in catheter-associated devices to prevent the initial colonization and thus can ease the burden of pathogenic biofilm-associated infections.

Multifunctional natural derived carbon quantum dots from Withania somnifera (L.) - Antiviral activities against SARS-CoV-2 pseudoviron.

Natural carbon dots (NCQDs) are expediently significant in the photo-, nano- and biomedical spheres owing to their facile synthesis, optical and physicochemical attributes. In the present study, three NCQDs are prepared and optimized from Withania somnifera (ASH) by one-step hydrothermal (bottom-up) method: HASHP (without dopant), nitrogen doped HASHNH3 (surface passivation using ammonia) and HASHEDA (surface passivation with ethylenediamine). The HR-TEM images reveal that HASHP, HASNH3, HASHEDA are spherically shaped with 2.5 ± 0.5 nm, 4 ± 1 nm and 5 ± 2 nm particle size, respectively, whereas FTIR confirms the aqueous solubility and nitrogen doping. The XRD patterns ensure that the NCQDs are amorphous and graphitic in nature. Comparatively, HASHNH3 (32.5%) and HASHEDA (27.6%) portray better fluorescence quantum yield than HASHP (5.6%). The increase in quantum yield for the doped NCQDs can be attributed to the surface passivation using ammonia and ethylenediamine. Surface passivation plays a crucial role in enhancing the fluorescence properties of quantum dots. The introduction of nitrogen through ammonia and ethylenediamine provides additional electronic states, possibly reducing non-radiative recombination sites and hence boosting the QY. In addition, an antiviral study unveils the striking potential of surface passivated NCQDs to curb Covid-19 crises with around 85% inhibition of SARS-CoV pseudoviron cells, which is better in comparison to the non-doped NCQDs. Hence, to understand the paramount efficacy of these NCQDs, a hypothesis on their possible mechanism of action against Covid-19 is discussed.

A mass conundrum.

A 30-year-old female presented to a rural hospital in Western Australia complaining of generalized abdominal pain and symptoms of partial bowel obstruction. Computed tomography (CT) showed a radiological 'whirl' sign, with images 4 years apart demonstrating interval progression. Given our patient's past history with miliary tuberculosis, we performed a diagnostic laparotomy which confirmed omental torsion. We report a case of surgically and pathologically proven chronic secondary omental torsion presenting with partial bowel obstruction, and showcase rarely seen interval progression on CT.

Hydrothermal Synthesis of Heterostructured g-C3N4/Ag-TiO2 Nanocomposites for Enhanced Photocatalytic Degradation of Organic Pollutants.

In this study, heterostructured g-C3N4/Ag-TiO2 nanocomposites were successfully fabricated using an easily accessible hydrothermal route. Various analytical tools were employed to investigate the surface morphology, crystal structure, specific surface area, and optical properties of as-synthesized samples. XRD and TEM characterization results provided evidence of the successful fabrication of the ternary g-C3N4/Ag-TiO2 heterostructured nanocomposite. The heterostructured g-C3N4/Ag-TiO2 nanocomposite exhibited the best degradation efficiency of 98.04% against rhodamine B (RhB) within 180 min under visible LED light irradiation. The g-C3N4/Ag-TiO2 nanocomposite exhibited an apparent reaction rate constant 13.16, 4.7, and 1.33 times higher than that of TiO2, Ag-TiO2, and g-C3N4, respectively. The g-C3N4/Ag-TiO2 ternary composite demonstrated higher photocatalytic activity than pristine TiO2 and binary Ag-TiO2 photocatalysts for the degradation of RhB under visible LED light irradiation. The improved photocatalytic performance of the g-C3N4/Ag-TiO2 nanocomposite can be attributed to the formation of an excellent heterostructure between TiO2 and g-C3N4 as well as the incorporation of Ag nanoparticles, which promoted efficient charge carrier separation and transfer and suppressed the rate of recombination. Therefore, this study presents the development of heterostructured g-C3N4/Ag-TiO2 nanocomposites that exhibit excellent photocatalytic performance for the efficient degradation of harmful organic pollutants in wastewater, making them promising candidates for environmental remediation.

Non-cytotoxic, highly functionalized cellulose nanocrystals with high crystallinity and thermal stability derived from a novel agromass of Elettaria cardamomum, using a soft and benign mild oxalic acid hydrolysis.

Non-cytotoxic, highly crystalline, and functionalized, thermally stable cellulose nanocrystals are extracted from the stems of Elettaria cardamom, a novel underutilised agromass, by employing a neat green, mild oxalic acid hydrolysis. The protocol involves a chemo-mechanical strategy of coupling hydrolysis with steam explosion and homogenization. The obtained CNC showed a crystallinity index of 81.51 %, an aspect ratio of 17.80 ± 1.03 and a high degradation temperature of about 339.07 °C. The extraction procedure imparted a high negative surface functionalization with a zeta potential value of -34.244 ± 0.496 mV and a polydispersity of 16.5 %. The CNC had no antibacterial activity, according to non-cytotoxic experiments conducted on four bacterial strains. This supports the notion of "One Health" in the context of AMR by demonstrating the safety of antibiotic resistance due to consistent exposure upon environmental disposal. The as-extracted nanocellulose crystals can be a potential candidate for commercial application in wide and diversified disciplines like food packaging, anti-infective surfaces for medical devices, biosensors, bioelectronics etc.

Phase Behavior and Role of Organic Additives for Self-Doped CsPbI3 Perovskite Semiconductor Thin Films.

The phase change of all-inorganic cesium lead halide (CsPbI3) thin film from yellow δ-phase to black γ-/α-phase has been a topic of interest in the perovskite optoelectronics field. Here, the main focus is how to secure a black perovskite phase by avoiding a yellow one. In this work, we fabricated a self-doped CsPbI3 thin film by incorporating an excess cesium iodide (CsI) into the perovskite precursor solution. Then, we studied the effect of organic additive such as 1,8-diiodooctane (DIO), 1-chloronaphthalene (CN), and 1,8-octanedithiol (ODT) on the optical, structural, and morphological properties. Specifically, for elucidating the binary additive-solvent solution thermodynamics, we employed the Flory-Huggins theory based on the oligomer level of additives' molar mass. Resultantly, we found that the miscibility of additive-solvent displaying an upper critical solution temperature (UCST) behavior is in the sequence CN:DMF > ODT:DMF > DIO:DMF, the trends of which could be similarly applied to DMSO. Finally, the self-doping strategy with additive engineering should help fabricate a black γ-phase perovskite although the mixed phases of δ-CsPbI3, γ-CsPbI3, and Cs4PbI6 were observed under ambient conditions. However, the results may provide insight for the stability of metastable γ-phase CsPbI3 at room temperature.

Poly(lactic acid)/cholecalciferol based composites for active food packaging application.

Poly(lactic acid) (PLA) based sustainable composites incorporated with cholecalciferol (Vitamin D3) (CC) at different concentrations (1, 3, 5 and 10 wt%) were prepared using solvent casting method. Performance analysis of PLA/CC composite films in terms of food packaging properties like thermal, optical, oxygen barrier, mechanical, anti-bacterial as well as anti-oxidant effect is carried out. The PLA/CC-5 composite showed complete blockage of UV-B light at 320 nm, which is known to significantly induce the photo-chemical degradation of polymers. The incorporation of CC in the PLA matrix brought in improvement in mechanical and oxygen barrier properties. The PLA composite films showed effective antibacterial activity against food borne bacteria (S. aureus and E. coli), in addition to excellent antioxidant activity. All these important traits exhibited by PLA/CC composite films suggest its potential for food packaging application.

All-Inorganic CsPbBr3 Perovskite Nanocrystals Synthesized with Olive Oil and Oleylamine at Room Temperature.

Room temperature (RT) synthesis of the ternary cesium lead bromide CsPbBr3 quantum dots with oleic acid and oleylamine ligands was developed by Zeng and coworkers in 2016. In their works, the supersaturated recrystallization (SR) was adopted as a processing method without requiring inert gas and high-temperature injection. However, the oleic acid ligand for haloplumbate is known to be relatively unstable. Hence, in this work, we employed the eco-friendly olive oil to replace the oleic acid portion for the SR process at RT. Resultantly, we found that the cube-shaped nanocrystal has a size of ~40-42 nm and an optical bandgap of ~2.3 eV independent of the surface ligands, but the photoluminescence lifetime (τav) and crystal packing are dependent on the ligand species, e.g., τav = 3.228 ns (olive oil and oleylamine; here less ordered) vs. 1.167 ns (oleic acid and oleylamine). Importantly, we explain the SR mechanism from the viewpoint of the classical LaMer model combined with the solvent engineering technique in details.

Cationic starch: A functionalized polysaccharide based polymer for advancement of drug delivery and health care system - A review.

Research and development in health care industry is in persistence progression. To make it more patient-friendly or to get maximum benefits from it, special attention to different advanced drug delivery system (ADDS) is employed that delivers the drug at the target site and will be able to sustain/control release of drugs. ADDS should be non-toxic, biodegradable, biocompatible along with desirable showing physicochemical and functional properties. These drug delivery systems can be totally based on polymers, either with natural or synthetic polymers. The molecular weight of polymer can be tuned and different groups of polymers can be modified or substituted with other functional groups. Degree of substitution is also tailored. Cationic starch in recent years is exploited in drug delivery, tissue engineering and biomedicine. Due to their abundant availability, low cost, easy chemical modification, low toxicity, biodegradability and biocompatibility, extensive research is now being carried out. Our present discussion will shed light on the usage of cationic starch in health care system.