WS2-intercalated Ti3C2Tx MXene/TiO2-stacked hybrid structure as an excellent sonophotocatalyst for tetracycline degradation and nitrogen fixation.

Designing a heterostructure nanoscale catalytic site to facilitate N2 adsorption and photogenerated electron transfer would maximize the potential for photocatalytic activity and N2 reduction reactions. Herein, we have explored the interfacial TiO2 nanograins between the Ti3C2TxMXene-WS2 heterostructure and addressed the beneficial active sites to expand the effective charge transfer rate and promote sonophotocatalytic N2 fixation. Benefiting from the interfacial contact and dual heterostructure interface maximizes the photogenerated carrier separation between WS2 and MXene/TiO2. The sonophotocatalytic activity of the MXene@TiO2/WS2 hybrid, which was assessed by examining the photoreduction of N2 with ultrasonic irradiation, was much higher than that of either sonocatalytic and photocatalytic activity because of the synergistic sonocatalytic effect under photoirradiation. The Schottky junction between the MXene and TiO2 on the hybrid MXene/TiO2-WS2 heterostructure resulted in the sonophotocatalytic performance through effective charge transfer, which is 1.47 and 1.24 times greater than MXene-WS2 for nitrogen fixation and pollutant degradation, respectively. Under the sonophotocatalytic process, the MXene/TiO2-WS2 heterostructure exhibits a decomposition efficiency of 98.9 % over tetracycline in 90 min, which is 5.46, 1.73, and 1.10 times greater than those of sonolysis, sonocatalysis, and photocatalysis, respectively. The production rate of NH3 on MXene/TiO2-WS2 reached 526 µmol g-1h-1, which is 3.17, 3.61, and 1.47 times higher than that of MXene, WS2, and MXene-WS2, respectively. The hybridized structure of MXene-WS2 with interfacial surface oxidized TiO2 nanograins minimizes the band potential and improves photocarrier use efficiency, contributing directly to the remarkable catalytic performance towards N2 photo fixation under visible irradiation under ultrasonic irradiation. This report provides the strategic outcome for the mass carrier transfer rate and reveals a high conversion efficiency in the hybridized heterostructure.

Deep eutectic solvents induced changes in the phase transition behavior of smart polymers: a sustainable future approach.

Deep eutectic solvents (DESs) are considered "green" and "sustainable" alternatives to conventional organic solvents and ionic liquids (ILs) due to their characteristic properties and relatively low costs. DESs are considered IL analogs and have attracted consideration as benign media formulations for the synthesis of novel polymers because they satisfy the principle of sustainability. Over the past few years, the use of DESs has resulted in novel pathways for the synthesis of novel materials, biomaterials, functional materials, and ionic soft materials. Furthermore, DESs have been widely applied in the science, industrial, engineering, and technological fields. On the other hand, stimulus-responsive (smart) polymers have been widely utilized in intelligent devices owing to their virtues of good processibility, stimuli and environmental sensitivity, responsivity, and so on. With the introduction of a DES into the smart polymeric matrices, their potential characteristics, biocompatibility, and flexibility endow the corresponding DES-based polymeric materials with intriguing properties, which in turn will broaden their applications in various domains of polymer science and material chemistry. Substantial research has been done in the fabrication of DES-based polymeric materials. Numerous studies have extensively investigated the effects of DESs on biomolecules such as proteins/enzymes and nucleic acids, whereas few have addressed the impact of DESs on the aggregation and phase transition behaviors of smart polymers. This review focuses on mechanistic insights, aggregation behavior, and interactions between smart polymers and DESs. Opportunities and future research perspectives in this blossoming arena are also discussed. It is hoped that this review will pave futuristic pathways for the design and development of advanced DES-based polymeric materials and biomaterials for various applications.

Microplastics and biobased polymers to combat plastics waste.

Microplastics (MPs) have become the major global concern due to their adverse effects on the environment, human health, and hygiene. These complex molecules have numerous toxic impacts on human well-being. This review focuses on the methods for chemically quantifying and identifying MPs in real-time samples, as well as the detrimental effects resulting from exposure to them. Biopolymers offer promising solutions for reducing the environmental impact caused by persistent plastic pollution. The review also examines the significant progress achieved in the preparation and modification of various biobased polymers, including polylactic acid (PLA), poly(ε-caprolactone) (PCL), lignin-based polymers, poly-3-hydroxybutyrate (PHB), and poly(hydroxyalkanoates) (PHA), which hold promise for addressing the challenges associated with unplanned plastic waste disposal.

Reply to Kapur, V. Is Pre-Exposure Prophylaxis a Cost-Effective Intervention to Avert Rabies Deaths among School-Aged Children in India? Comment on "Royal et al. A Cost-Effectiveness Analysis of Pre-Exposure Prophylaxis to Avert Rabies Deaths in School-Aged Children in India. Vaccines 2023, 11, 88".

Thank you so much for forwarding the critical analysis the author (VK) conducted on our recently published modelling study 'A Cost-Effectiveness Analysis of Pre-Exposure Prophylaxis to Avert Rabies Deaths in School-Aged Children in India' in your reputed journal [...].

Agro-waste to sustainable energy: A green strategy of converting agricultural waste to nano-enabled energy applications.

The rising demands of the growing population have raised two significant global challenges viz. energy crisis and solid-waste management, ultimately leading to environmental deterioration. Agricultural waste (agro-waste) contributes to a large amount of globally produced solid waste, contaminating the environment, and raising human-health issues on improper management. It is essential for a circular economy to meet sustainable development goals and to design strategies to convert agro-waste into energy using nanotechnology-based processing strategies, by addressing the two significant challenges. This review illustrates the nano-strategic aspects of state-of-the-art agro-waste applications for energy harvesting and storage. It details the fundamentals related to converting agro-waste into energy resources in the form of green nanomaterials, biofuels, biogas, thermal energy, solar energy, triboelectricity, green hydrogen, and energy storage modules in supercapacitors and batteries. Besides, it highlights the challenges associated with agro-waste-to-green energy modules with their possible alternate solutions and advanced prospects. This comprehensive review will serve as a fundamental structure to guide future research on smart agro-waste management and nanotechnological innovations dedicated to its utilization for green energy applications without harming the environment. The nanomaterials assisted generation and storage of energy from agro-waste is touted to be the near-future of smart solid-waste management strategy for green and circular economy.

Ionic Liquids Mediated Micellization of Pluronic Copolymers: Aggregation Behavior of Amphiphilic Triblock Copolymers.

Understanding the micellization of amphiphilic triblock copolymers, especially Pluronics can play a persuasive role in engineering "smart" formulations for drug delivery applications. Their underlying self-assembly in the presence of designer solvents such as ionic liquids (ILs) provides combinatorial benefits of unique munificent properties of ILs and copolymers. The complex molecular interactions in the Pluronic copolymers/ILs mixed system influence the aggregation mechanism of copolymers depending on various aspects with no standardized factors to govern the structure-property relationship, which led to the practical applications. Here, we summarized recent progress in understanding the micellization process of IL-Pluronic mixed systems. Special emphasis was given to pure Pluronic systems (i.e., PEO-PPO-PEO) without any structural modifications, such as copolymerization with other functional groups, and ILs having cholinium and imidazolium groups. We expect that the correlation between existing/developing experimental and theoretical studies will provide the necessary basis and impetus for successful utilization in drug delivery applications.

Effect of Imidazolium Nitrate Ionic Liquids on Conformational Changes of Poly(N-vinylcaprolactam).

Detailed information about molecular interactions and conformational changes of polymeric components in the presence of ionic liquids (ILs) is essential for designing novel polymeric ionic liquid-based biomaterials. In biomaterials science and technology, thermoresponsive polymers (TRPs) are widely viewed as potential candidates for the fabrication of biorelated medical devices. Here, we synthesized thermoresponsive poly(N-vinyl-caprolactam) (PVCL) polymer and investigated the effects of imidazolium-based ILs (1-ethyl-3-methyl imidazolium nitrate and 1-butyl-3-methylimidazolium nitrate) with common anion and different cations on the phase transition behavior of PVCL aqueous solution. The impact of ILs on the phase transition behavior of PVCL was monitored by using UV-visible absorption spectra, steady-state fluorescence spectroscopy, thermal fluorescence spectroscopy, and temperature dependent dynamic light scattering. Results showed significant changes in the absorbance, molecular interactions, agglomeration, and coil to globule transition behaviors of PVCL in the presence of two ILs. PVCL aqueous solution showed significant conformational changes after the addition of ILs.

A highly sensitive lateral flow immunoassay for the rapid and on-site detection of enrofloxacin in milk.

Enrofloxacin (ENR) is a veterinary antibiotic used to treat bacterial infections in livestock. It chiefly persists in foods and dairy products, which in turn pose severe risks to human health. Hence it is very important to detect the ENR in foods and dairy products to safeguard human health. Herein, we attempted to develop a single-step detection lateral flow immunochromatographic assay (LFIA) using gold nanoparticles (AuNPs) for the rapid and on-site detection of ENR in milk samples. An anti-enrofloxacin monoclonal antibody (ENR-Ab) was conjugated with AuNPs for the specific detection of ENR in milk samples. For sensitivity improvement, many optimization steps were conducted on LFIA test strips. The visual limit of detection (vLOD) was found to be 20 ng/ml with a cut-off value of 50 ng/ml in the milk samples. The obtained LOD and cut-off value were within the safety limit guidelines of the Ministry of food and drug safety, South Korea. The test strip showed negligible cross-reactivity with ENR analogs, and other components of antibiotics, this indicates the high specificity of the LFIA test strip towards ENR. The designed test strip showed good reliability. The visual test results can be seen within 10 min without the need for special equipment. Therefore, the test strip can be employed as a potential detection strategy for the qualitative on-site detection of enrofloxacin in milk samples.

An Overview on Single-Cell Technology for Hepatocellular Carcinoma Diagnosis.

Hepatocellular carcinoma is a primary liver cancer caused by the accumulation of genetic mutation patterns associated with epidemiological conditions. This lethal malignancy exhibits tumor heterogeneity, which is considered as one of the main reasons for drug resistance development and failure of clinical trials. Recently, single-cell technology (SCT), a new advanced sequencing technique that analyzes every single cell in a tumor tissue specimen, aids complete insight into the genetic heterogeneity of cancer. This helps in identifying and assessing rare cell populations by analyzing the difference in gene expression pattern between individual cells of single biopsy tissue which normally cannot be identified from pooled cell gene expression pattern (traditional sequencing technique). Thus, SCT improves the clinical diagnosis, treatment, and prognosis of hepatocellular carcinoma as the limitations of other techniques impede this cancer research progression. Application of SCT at the genomic, transcriptomic, and epigenomic levels to promote individualized hepatocellular carcinoma diagnosis and therapy. The current review has been divided into ten sections. Herein we deliberated on the SCT, hepatocellular carcinoma diagnosis, tumor microenvironment analysis, single-cell genomic sequencing, single-cell transcriptomics, single-cell omics sequencing for biomarker development, identification of hepatocellular carcinoma origination and evolution, limitations, challenges, conclusions, and future perspectives.

Hybridized 1D-2D MnMoO4-MXene nanocomposites as high-performing electrochemical sensing platform for the sensitive detection of dihydroxybenzene isomers in wastewater samples.

Hydroquinone (HQ) and catechol (CC) are the two major dihydroxybenzene isomers, are considered one of the toxic pollutants in wastewater, which often coexisted and impede each other during sample identification. For practical analysis and simultaneous detection of HQ and CC in wastewater, we fabricate a hybrid electrochemical sensor with electrospun one-dimensional (1D) MnMoO4 nanofibers coupled with a few-layered exfoliated two-dimensional (2D) MXene. The facilitated abundant defective edges of 1D MnMoO4 and 2D MXene nanoarchitecture accelerated the effect of synergistic signal amplification and exhibited high electrocatalytic activity towards the oxidation of hydroquinone and catechol. MnMoO4-MXene-GCE showed oxidation potentials of 0.102 V and 0.203 V for hydroquinone and catechol, respectively. It revealed the distinguished and simultaneous detection range of 0.101 V with a strong anodic peak current. Noteworthily, the proposed 1D-2D hybridized MnMoO4-MXene-GCE sensor exhibited a wide linear response from 5 nM to 65 nM for hydroquinone and catechol. Moreover, it showed a low detection limit of 0.26 nM and 0.30 nM for HQ and CC with high stability, respectively. The feasible 1D-2D MnMoO4-MXene nanocomposite-based biosensor effectively detected hydroquinone and catechol in hazardous water pollutants using the differential pulse voltammetric technique with recovery values.

A Cost-Effectiveness Analysis of Pre-Exposure Prophylaxis to Avert Rabies Deaths in School-Aged Children in India.

Children contribute to one-half of the total painful rabies mortalities in India. The state-of-the-art rabies mortality averting strategies need exploration for the effective implementation of pre-exposure prophylaxis (PrEP) in India. This study reports on the economic evaluation of various PrEP and post-exposure prophylaxis (PEP) strategies to avert rabies mortalities in school-aged children in India. A decision tree model has been developed for children in the age group of 5-15 years to evaluate various PrEP + PEP and PEP only regimens. The 2-site intradermal regimen administered on day zero and seven was chosen as the intervention [PrEP (I)]. ICER was calculated from the quasi-societal and quasi-health systems' perspectives for the base case analysis, along with one-way sensitivity, and scenario analyses for each regimen. The incremental DALYs averted per million population with the implementation of PrEP (I) ranged between 451 and 85,069 in 2020. The ICER was reported in the range of USD 384-352/DALY averted (non-dominant) in comparison to PEP regimens from a quasi-societal perspective. PrEP (I) is reported to be 'very cost effective' in comparison with PEP regimens from the quasi-societal and quasi-health systems' perspectives and reduce deaths by up to 89.9%. This study concludes that the PrEP (I) regimen is a cost-effective and life-saving strategy to avert painful mortalities due to rabies in school-aged children in India.

Fabrication of Carbon Disulfide Added Colloidal Gold Colorimetric Sensor for the Rapid and On-Site Detection of Biogenic Amines.

Meat is often wasted due to the perceived concerns of its shelf life and preservation. Specifically, in meat formation, biogenic amines (BAs) are the major agents to spoil them. Herein, we have developed a carbon disulfide (CS2) added colloidal gold nanoparticles-based colorimetric sensor for the rapid and on-site detection of biogenic amines. Transmission electron microscopy is used to observe the morphological changes in colloidal gold nanoparticles and aggregation behavior of CS2 added to the colloidal gold nanoparticles' solution. Raman spectroscopic analysis is further used to characterize the peaks of CS2, Cad and CS2-Cad molecules. Absorption spectroscopy is used to estimate the colorimetric differences and diffuse reflectance spectra of the samples. The sensing analysis is performed systematically in the presence and absence of CS2. CS2 added colloidal gold nanoparticles colorimetric sensor detected the BAs with a limit of detection (LOD) value of 50.00 µM. Furthermore, the developed sensor has shown an LOD of 50.00 µM for the detection of multiple BAs at a single time. The observed differences in the colorimetric and absorption signals indicate that the structure of BAs is converted to the dithiocarbamate (DTC)-BA molecule, due to the chemical reactions between the amine groups of BAs and CS2. Significantly, the developed colorimetric sensor offers distinct features such as facile fabrication approach, on-site sensing strategy, rapid analysis, visual detection, cost-effective, possibility of mass production, availability to detect multiple BAs at a single time and appreciable sensitivity. The developed sensor can be effectively used as a promising and alternative on-site tool for the estimation of BAs.

Multilayered PVDF-HFP Porous Separator via Phase Separation and Selective Solvent Etching for High Voltage Lithium-Ion Batteries.

The development of highly porous and thin separator is a great challenge for lithium-ion batteries (LIBs). However, the inevitable safety issues always caused by poor mechanical integrity and internal short circuits of the thin separator must be addressed before this type of separator can be applied to lithium-ion batteries. Here, we developed a novel multilayer poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) membrane with a highly porous and lamellar structure, through a combination of evaporation-induced phase separation and selective solvent etching methods. The developed membrane is capable of a greater amount of electrolyte uptake and excellent electrolyte retention resulting from its superior electrolyte wettability and highly porous structure, thereby offering better electrochemical performance compared to that of a commercial polyolefin separator (Celgard). Moreover, benefiting from the layered configuration, the tensile strength of the membrane can reach 13.5 MPa, which is close to the mechanical strength of the Celgard type along the transversal direction. The elaborate design of the multilayered structure allows the fabrication of a new class of thin separators with significant improvements in the mechanical and electrochemical performance. Given safer operation, the developed multilayer membrane may become a preferable separator required for high-power and high-energy storage devices.

Simple synthesis of a clew-like tungsten carbide nanocomposite decorated with gold nanoparticles for the ultrasensitive detection of tert-butylhydroquinone.

The excessive use of food additives in manufactured food products negatively affects their quality and potentially impacts human health. In the present study, a composite consisting of gold nanoparticles decorated on tungsten carbide (AuNP-WC) was successfully fabricated using a facile and cost-effective ultrasonication technique. Compared to a bare glassy carbon electrode (GCE), AuNP-GCE, and WC-GCE, the AuNP-WC-GCE demonstrated excellent sensing performance for tert-butylhydroquinone (TBHQ) when used as an electrocatalyst in 0.05 M phosphate buffer solution (PBS), with a low working potential and a high peak current. In particular, the composite was able to detect the oxidation of TBHQ within a linear concentration range of 5 to 75 nM, with an extremely low detection limit of 0.20 nM. The practicability of the sensor was also assessed in the analysis of TBHQ in real samples of soybean oil, blended oil, and red wine, with satisfactory recovery rates obtained.

Biological Stimuli-Induced Phase Transition of a Synthesized Block Copolymer: Preferential Interactions between PNIPAM-b-PNVCL and Heme Proteins.

The beguiling world of functional polymers is dominated by thermoresponsive polymers with unique structural and molecular attributes. Limited work has been reported on the protein-induced conformational transition of block copolymers; furthermore, the literature lacks a clear understanding of the influence of proteins on the phase behavior of thermoresponsive copolymers. Herein, we have synthesized poly(N-isopropylacrylamide)-b-poly(N-vinylcaprolactam) (PNIPAM-b-PNVCL) by RAFT polymerization using N-isopropylacrylamide and N-vinylcaprolactam. Furthermore, using various biophysical techniques, we have explored the effect of cytochrome c (Cyt c), myoglobin (Mb), and hemoglobin (Hb) with varying concentrations on the aggregation behavior of PNIPAM-b-PNVCL. Absorption and steady-state fluorescence spectroscopy measurements were performed at room temperature to examine the copolymerization effect on fluorescent probe binding and biomolecular interactions between PNIPAM-b-PNVCL and proteins. Furthermore, temperature-dependent fluorescence spectroscopy and dynamic light scattering studies were performed to get deeper insights into the lower critical solution temperature (LCST) of PNIPAM-b-PNVCL. Small-angle neutron scattering (SANS) was also employed to understand the copolymer behavior in the presence of heme proteins. With the incorporation of proteins to PNIPAM-b-PNVCL aqueous solution, LCST has been varied to different extents owing to the preferential, molecular, and noncovalent interactions between PNIPAM-b-PNVCL and proteins. The present study can pave new insights between heme proteins and block copolymer interactions, which will help design biomimetic surfaces and aid in the strategic fabrication of copolymer-protein bioconjugates.

Pd-Cu nanospheres supported on Mo2C for the electrochemical sensing of nitrites.

The improper disposal in agricultural and industrial wastewater leads to high NO2- concentrations in the aquatic environment, which can cause cancer in humans and animals; thus, their quick and accurate detection is urgently needed to ensure public health and environmental safety. In this study, a reliable and selective electrochemical sensor consisting of Pd-Cu nanospheres (NSs) supported on molybdenum carbide was prepared via simple ultrasonication. Then, a glassy carbon electrode was realized using this composite (Pd-Cu-Mo2C-modified GCE) to test its electrocatalytic sensing for NO2- in a 0.1 M phosphate-buffered solution (PBS) solution via cyclic voltammetry and amperometry; at a low oxidation potential, the anodic peak current of NO2- detected by this electrode was significantly higher than that of its unmodified and other modified electrodes. The sensor showed a broad linear response in the 5-165-nM NO2- concentration range, with a low detection limit (0.35 nM in 0.1 M PBS) and high sensitivity (3.308 µAnM-1 cm-2). Moreover, the fabricated electrode was successfully applied for detecting nitrites in sausages, river water, and milk, showing also good recovery.

Improved conductivity of flower-like MnWO4 on defect engineered graphitic carbon nitride as an efficient electrocatalyst for ultrasensitive sensing of chloramphenicol.

Environmental hazards caused by chloramphenicol has attained special attention. Fast, accurate and reliable detection of chloramphenicol in foodstuffs and water samples is of utmost importance. Herein, we developed a g-C3N4/MnWO4 composite for the selective and sensitive detection of chloramphenicol. Successful fabrication of g-C3N4/MnWO4 composite was verified by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), x-ray diffraction (XRD) and x-ray photo electron spectroscopy (XPS) techniques. Electrochemical characteristics were evaluated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). The g-C3N4/MnWO4 modified glassy carbon electrode has shown the highest electrocatalytic activity towards chloramphenicol with a decreased reduction potential of -0.547 V and increased cathodic peak current. The developed sensor has shown excellent performance for the detection of chloramphenicol with a sensitivity of 0.9986 µA nM-1 cm-2 and LOD of 1.03 nM in a broad linear range of 4.0-71 nM. In addition, the fabricated sensor has achieved anti-interference ability, good stability, excellent repeatability and remarkable reproducibility for the detection of chloramphenicol. The fabricated sensor applied for the determination of chloramphenicol in milk, human blood serum and sewage samples, in which significant and satisfactory results were achieved.

A simple strategy for the synthesis of flower-like textures of Au-ZnO anchored carbon nanocomposite towards the high-performance electrochemical sensing of sunset yellow.

Consumption of sunset yellow (SY) above a certain concentration through food products may leads to adverse health issues. Therefore, it is imperative to develop technologies for rapid and selective detection of SY. Herein, a flower-like reduced graphene oxide (rGO)-graphitic carbon nitride (g-CN)/ZnO-Au nanoparticle (NPs) has been prepared and utilized for the specific detection of SY. The fabricated rGO-g-CN/ZnO-AuNPs composite was characterized and investigated by XRD, FTIR, SEM, TEM, XPS, EIS, and voltammetry techniques. Characterization techniques elucidated the deposition of ZnO-AuNPs on to the rGO-g-CN and successful fabrication of rGO-g-CN/ZnO-AuNPs composite. rGO-g-CN/ZnO-AuNPs composite possesses excellent catalytic activity for the oxidation of SY. Developed rGO-g-CN/ZnO-AuNPs sensor exhibits LOD of 1.34 nM for SY concentrations ranging from 5 to 85 nM. Noteworthily, the sensor has been successfully employed for the detection and recovery of SY in real-time samples. Fabricated composite opens up new avenues to develop electrochemical sensor for food safety.

How does bovine serum albumin sustain in saccharomate® derived from pine tree biomass?

Nowadays, research on renewable raw materials and bioresources is a new concern towards the promotion of sustainable process and product development. The use of various plant biomasses such as starch, lignocellulosic and saccharide can be considered as an alternative for using cheaper and less polluting raw materials. In this regard, pine tree biomass, a lignocellulosic forest residue that has various value-added importance and it acts as a model of economic value to the agro-industrial fields. On the other hand, in order to meet and address the challenges of ever-increasing demands of bioresources, there has been significant research interest in deciphering the molecular interactions between proteins and biomass derived substances. No study reports the significance of saccharomate® derived from pine tree biomass on the structural and thermal stability of proteins. There is a sizable interest in the interactions between proteins and biomass derived substances, owing to their utilization and applications. Herein, we used various biophysical techniques such as absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) and dynamic light scattering (DLS) to study the impact of pine tree biomass derived saccharomate® (PBDS) on bovine serum albumin (BSA). Further for better understanding of morphological changes of BSA in presence of biomass, Transmission electron microscopy (TEM) was also studied. The present study revealed that the increasing concentration of saccharomate® perturbs structural stability however; the thermal stability of BSA remained unchanged. The transition temperature of BSA remained approximately same in presence of different concentrations of PBDS. Furthermore, the size of BSA increases from 9.22 nm to 135.58 nm in presence of higher concentration of PBDS as revealed by DLS studies. To the best of our knowledge, the results represent first detailed proof of the unusual effect of PBDS on the model protein BSA.

Influence of biological stimuli on the phase behaviour of a biomedical thermoresponsive polymer: A comparative investigation of hemeproteins.

HYPOTHESIS: Thorough knowledge of the biomolecular interactions between thermoresponsive polymers (TRPs) and proteins are necessary to fabricate potential materials for various bio-related science and technology applications. Although over the past four decades have evidenced that tremendous growth in the utilization of TRPs in the addition of various stimuli systems, a underlying molecular origins of the role of biological stimuli on TRPs phase transition is still missing. EXPERIMENTS: We demonstrated the comparative effect of heme proteins (biological stimuli) such as cytochrome c (Cyt c) and myoglobin (Mb) on the phase behaviour of poly(N-isopropylacrylamide) (PNIPAM) aqueous solution. The sophisticated multiple techniques have confirmed that the structural integrity of the proteins is found to play a vital role in altering the phase transition temperature of PNIPAM to different extents with increasing the concentration of proteins. FINDINGS: With the addition of Cyt c, the lower critical solution temperature (LCST) of PNIPAM (33.0 °C) increased towards higher temperature (35.7 °C) in contrast to this with the addition of Mb the LCST of PNIPAM decreased towards lower temperature (30.7 °C). This discrepancy is due to the difference in contrast structural arrangements of both proteins on the LCST of PNIPAM. On the basis of these results, the variation in the structures of both heme proteins, hydration and dehydration between the heme proteins are compared. These results demonstrated that depending on the type of smart polymers used for bio-related applications, it is necessary to take into account the effect of biological stimuli while designing polymers. We hope that the present study can stimulate more novel concepts and dramatic changes in smart polymer and protein interactions.