In the present work, Cr doped tellurium dioxide nanostructures (CTO NS)(1 wt %, 6 wt %, 8 wt % and 12 wt %) synthesized by co precipitation method and characterized by CV, UV‐Visible, SEM, XRD, XPS ...spectroscopic analysis. Electron beam deposited thin film of CTO NS having 12 wt % of Cr exhibited EGFET‐pH sensitivity of 62.03 mV/pH at 250 °C in buffer solutions of pH 6–12, linearity 0.9345, drift rate of 1.12 mV/h and deviation of 0.01145 as compared with 1 wt %, 6 wt % and 8 wt % of CTO NS.
An antineoplastic drug‐free anticancer strategy enabled by host defense peptides (HDPs)‐mimicking synthetic polypeptides is reported. The polypeptide exhibits a broad spectrum of anticancer activity ...in 12 cancer cell lines, including drug‐resistant and highly metastatic tumor cells. Detailed mechanistic studies reveal that the cationic anticancer polypeptide (ACPP) can directly induce rapid necrosis of cancer cells within minutes through a membrane‐lytic mechanism. Moreover, a pH‐sensitive zwitterionic derivative of ACPP (DA‐ACPP) is prepared for in vivo application. DA‐ACPP shows negligible hemolysis under neutral physiological conditions, and can be converted back to ACPP in slightly acidic tumor environments, resulting in selective killing of cancer cells. Consequently, DA‐ACPP shows an effective inhibition of tumor growth in both 4T1 orthotopic breast tumor models and B16‐F10 melanoma pulmonary metastatic models. Overall, these findings demonstrate that synthetic HDPs‐mimicking polypeptides represent safe and effective antineoplastic agents, which sheds new light on the development of drug‐free synthetic polymers for cancer therapy.
An antineoplastic drug‐free anticancer strategy enabled by host defense peptides (HDPs)‐mimicking synthetic polypeptides is proposed. The synthetic anticancer polypeptides (ACPP) exhibit broad‐spectrum anticancer activity through an HDPs‐like membrane‐lytic mechanism. Modification of ACPP with 2,3‐dimethylmaleic anhydride (DA) generates a pH‐sensitive zwitterionic derivative, DA‐ACPP, with improved biocompatibility, which can selectively lyse tumors in vivo after being activated in acidic tumor microenvironment.
In our study, Al-doped β-Ga2O3 microrods were deposited on FTO glass substrate via hydrothermal method followed by calcination at 700 °C for 3 h. The Al-doped β-Ga2O3 microrods were characterized ...using XRD, SEM, XPS, and FTIR spectroscopy techniques. The intrinsic β-Ga2O3 extended-gate field-effect transistor (EGFET)-based pH sensor exhibited a pH sensitivity of 57.29 mV/pH with 99.34 % linearity within the pH range of 3–11. Conversely, the Al-doped β-Ga2O3 EGFET-pH sensor, containing 0.52 at. % of Al, demonstrated an elevated pH sensitivity of 77.63 mV/pH with 99.17 % linearity. Our findings indicate that the incorporation of Al enhances the pH sensing capabilities of β-Ga2O3 microrods to the presence of additional binding sites facilitated by its improved specific surface area. Remarkably, even a minute amount (0.52 at. %) of Al doping in β-Ga2O3 suffices to significantly improve the performance of pH sensing. These results underscore the potential of Al-doped β-Ga2O3 as a promising material for development of high-performance ion or biosensors.
Al-doped α-GaOOH was deposited onto commercially available fluorine-doped tin oxide (FTO) glass substrates using the hydrothermal method. The annealed samples align with the monoclinic β-Ga2O3 phase. Al-doped β-Ga2O3 EGFET-pH sensor, containing 0.52 at. % of Al, demonstrated an elevated pH sensitivity of 77.63 mV/pH with 99.17 % linearity. This process is shown schematically in the graphical abstract. Display omitted
•Al-doped β-Ga2O3 particles were successfully deposited on FTO by hydrothermal method.•Al-doped β-Ga2O3 micro rods based EGFET pH sensor is fabricated.•The pH sensitivity of Al-doped β-Ga2O3 microrods was investigated for varying Al doping concentrations (0 mM/L to 6 mM/L).•The Al-doped β-Ga2O3 pH sensor exhibited higher pH sensitivity compared to intrinsic β-Ga2O3 microrods.
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•Sensitive and easy-to-use sensor for detection of cysteine.•Sensitivity assessment by sensor response and plasmon shift methods.•Enhancement in sensitivity and decrease in LOD by ...using the pH-sensitive polymer.•Performance control for real samples from human blood serum.
The development of a highly sensitive and easy-to-prepare sensor for the detection of cysteine (Cys) is of great importance. Gold nanoparticles (AuNPs) have been frequently utilized as a Cys sensor owing to high affinity of the thiol group to gold. However, the presence of additional materials, such as stabilizers, can impact the sensitivity of this sensor. Herein, pH-sensitive gold nanoparticles (Au-PDA) were synthesized using poly (N,N-dimethylaminoethyl methacrylate) (PDMAEMA) for the purpose of Cys detection based on the aggregation size-dependent optical property of gold nanoparticles. Detection of cysteine was also followed by UV–Vis analysis, showing a decrease in intensity of localized surface plasmon resonance (LSPR) peak, a red shift from 525 to 550 nm as well as the appearance of a new peek at 650 nm. To enhance sensor performance, systematic investigations were conducted to optimize sensing conditions, focusing on pH, gold concentration, and ionic strength of the medium. Remarkably, the proposed sensor exhibited excellent selectivity towards Cys compared to other amino acids. The sensitivity of the sensor was evaluated using two methods: changes in the absorption intensity and the LSPR shift. The pH-sensitivity of PDMAEME led to a significant improvement in sensing parameters through a synergistic effect on the Au-Cys interaction, leading to a remarkably low LOD of 0.0004 nM, which is the lowest ever reported LOD for detection of Cys. Finally, practical application of the proposed sensor was validated in human blood serum.
To improve the efficacy of chemotherapy and relieve the pain associated with colorectal cancer, a dual-drug delivery system (DDDS) is proposed. In this system, methotrexate (MTX) loaded CaCO3 ...(CaCO3/MTX) and aspirin (Asp) are co-entrapped in the hydrogels of alginate (Alg) and sodium carboxymethyl cellulose (CMC) crosslinked with Ca2+. The hydrogels can protect the anti-cancer drug of MTX from being absorbed in stomach and small intestine and ensure their efficacy at the target site of colorectum. More importantly, dual pH-responsive drug delivery can be achieved by the DDDS. Because the pH varies at small intestine and colorectum of human body, dual pH-responsive delivery of Asp and MTX can be achieved at the two organs, respectively, in response to ambient pH. These finding are of significant importance for medical science and pharmaceutics.
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•A dual pH-sensitive DDDS based on CaCO3 microspheres-entrapped hydrogels is designed.•The hydrogels can protect MTX from being absorbed in stomach and small intestine.•Kinetic release curves reveal that dual pH-responsive drug delivery can be achieved.•The developed DDDS exhibits excellent biocompatibility on normal cells.
A pH-sensitive food freshness indicator film (PS-CS-BA) was fabricated with potato starch (PS) as film-forming substrate, blueberry anthocyanins (BA) as an indicator, and chondroitin sulfate (CS) as ...an enhancer. The results exhibited that the presence of CS significantly altered water solubility and improved mechanical properties of films, in particular enhanced pH and ammonia responsiveness. FT-IR and XRD results associated with the enhanced pH sensitivity and colorimetry with the ionic complex between the sulfate group of CS and anthocyanin flavylium ion. When applied in monitoring shrimp freshness at 4 °C, the PS–CS–BA film indicated sensitively with vision recognizable color changes from original pink to light grey and finally to grayish-green, which highly correlated with the deterioration indexes of the total volatile basic nitrogen (TVB-N), total viable count (TVC), and pH values of shrimp. The results provided a novel and highly-sensitive intelligent packaging strategy by the co-pigmentation of CS for freshness monitoring.
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•PS–CS–BA film was fabricated with starch, chondroitin sulfate and anthocyanins.•Ionic complexes between chondroitin sulfate and anthocyanin produce co-pigmentation.•The addition of chondroitin sulfate enhanced colorimetric and physical properties.•PS–CS–BA film clearly indicated the freshness degree of shrimp during storage.
•Xylan-based P(NIPAm-co-AA) hydrogels were prepared.•These hydrogels were temperature/pH sensitive and biocompatible.•LCST of hydrogels was at 34°C and increased with increasing the AA content.•The ...drug cumulative release rate was 90% and 26% in intestinal and gastric fluids.•They could be used as drug carriers for intestinal-targeted oral drug delivery.
Xylan-based temperature/pH sensitive hydrogels were prepared by the crosslinking copolymerization of xylan with N-isopropylacrylamide (NIPAm) and acrylic acid (AA) using N,Ń-methylenebis-acrylamide (MBA) as a cross-linker and 2,2-dimethoxy-2-phenylacetophenone as a photoinitiator via ultraviolet irradiation. The influence of the NIPAm, AA and MBA amount on properties of xylan-based hydrogels was discussed. The morphology and interactions of hydrogels were characterized by SEM and FTIR. The lower critical solution temperature (LCST) of hydrogels was investigated by DSC. The results indicated that the LCST of hydrogels emerged at around 34°C and increased with increasing the AA content. The drug encapsulation efficiency of as-prepared hydrogels reached to 97.60% and the cumulative release rate of acetylsalicylic acid was 90.12% and 26.35% in the intestinal and gastric fluid, respectively. Xylan-based hydrogels were proved to be biocompatible with NIH3T3 cell by MTT assay and showed the promising application as drug carriers for the intestinal-targeted oral drug delivery.
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•Chitosan nanoparticles (CHNPs) were prepared by ionotropic gelation method.•CHNPs were used to enhance the physical properties of PVA films.•Intelligent films were developed by ...adding Mulberry extracts into PVA/CHNPs films.•The intelligent film showed sensitive color response to pH solutions.•The colorimetric films can be used to monitor the fish spoilage.
The aim of this study was to prepare a visually responsive intelligent film based on poly (vinyl alcohol) (PVA), chitosan nanoparticles (CHNPs) and mulberry extracts (MBE). CHNPs were first prepared by using ionotropic gelation method to enhance the mechanical properties of PVA based films. The morphology, particle size, zeta potential and crystallinity of CHNPs were measured. The resultant CHNPs were spherical with a diameter of 381.2nm, with high stability and a zeta potential of 49.1±1.33mV. The film with 6% CHNPs (P-C6) had the highest tensile strength (∼73.43MPa). MBE was incorporated into the P-C6 film. The film containing 20% MBE had the highest tensile strength and showed visible color responses to variations across pH 1–13. The film was tested by monitoring the spoilage of fish. The color of the film changed from red to green as the fish spoiled. Therefore, the pH responsive intelligent film developed here can be used as a package label to detect food spoilage.
Gold nanoparticles (AuNPs) pose a great challenge in the development of nanotracers that can self‐adaptively alter their properties in response to certain cellular environments for long‐term stem ...cell tracking. Herein, pH‐sensitive Au nanotracers (CPP‐PSD@Au) are fabricated by sequential coupling of AuNPs with sulfonamide‐based polymer (PSD) and cell‐penetrating peptide (CPP), which can be efficiently internalized by mesenchymal stem cells (MSCs) and undergo pH‐induced self‐assembly in endosomes, facilitating long‐term computed tomography (CT) imaging tracking MSCs in a murine model of idiopathic pulmonary fibrosis (IPF). Using the CPP‐PSD@Au, the transplanted MSCs for the first time can be monitored with CT imaging for up to 35 days after transplantation into the lung of IPF mice, clearly elucidating the migration process of MSCs in vivo. Moreover, we preliminarily explored the mechanism of the CPP‐PSD@Au labeled MSCs in the alleviation of IPF, including recovery of alveolar integrity, decrease of collagen deposition, as well as down‐regulation of relevant cytokine level. This work facilitates our understanding of the behavior and effect of MSCs in the therapy of IPF, thereby providing an important insight into the stem cell‐based treatment of lung diseases.
A pH‐sensitive nanotracer, CPP‐PSD@Au, is fabricated by sequential coupling of AuNPs with polymer polysulfonamide (PSD) and cell‐penetrating peptide (CPP), which can undergo self‐assembly aggregation in cells for long‐term CT imaging tracking of MSCs in vivo, thus providing a new insight into the role of the MSCs in pulmonary fibrosis treatment.
•Synthesis of a pH/temperature dual-responsive magnetic molecularly imprinted polymer.•Optimization the molar ratio of multifunctional monomer-template through DFT calculation.•Reduced the required ...number of experiments for the optimization.•Exhibiting high pH and temperature dependence for the adsorption of PTBG-MIP.•High application efficiency for the composite in the extraction and purification of gallic acid.
A pH/temperature bi-responsive gallic acid magnetic imprinted polymer (PTBG-MIP) was synthesized on a Fe3O4@SiO2@KH570 carrier using methacrylic acid (MAA), p-Vinylphenylboronic acid (p-VPBA), and N-isopropyl-acrylamide (NIPAAm) as complex functional monomers. The density functional theory (DFT) was employed to optimize the molar ratio of multi-functional monomers-template complex, which proved to be an effective tool for predicting complex configuration based on electrostatic potential (ESP) analysis and the lowest binding energy. DFT calculation and analysis determined the optimized molar ratio of 2:1:1:1 for GA-MAA-NIPAAm-p-VPBA, which showed good agreement with experimental results. The PTBG-MIP-4 obtained under the optimized conditions exhibited high pH- and temperature- dependence in rebinding the template, displaying a maximum adsorption capacity (Qe) of 62.26 mg g−1 and a highest selection factor (α) of 5.217. Additionally, the PTBG-MIP-4 exhibited exceptional physicochemical properties encompassing magnetization characteristics, morphology, surface sites distribution, and adsorption performance. The application efficiency of this imprinted composite in the extraction and purification of gallic acid from Galla chinensis was remarkably demonstrated.
