ACS Applied Bio Materials最新文献

Proteins play a crucial role in determining disease states in humans, making them prime targets for the development of diagnostic sensors. The developed sensor array is used to investigate global proteomic changes by fingerprinting multifactorial disease states in model urine simulating phenylketonuria and in serum from preeclamptic pregnant women. Here, we report a fluorescence-based chemical sensing array that exploits the host-guest interaction between cucurbit[7]uril (CB[7]) and fluorescent triphenylamine derivatives (TPA) to detect a range of proteins. Using linear discriminant analysis, we identify fluorescence fingerprints of 14 proteins with over 98% accuracy in buffer and human serum. The array is optimized on an automated droplet microfluidic-based platform, for high-throughput sensing with controlled composition and lower sample volumes. This sensor enables the discrimination of proteins in physiological buffer and human serum, with promising applications in disease diagnosis.

A near-infrared fluorescent probe, A, was designed by substituting the carbonyl group of the coumarin dye's lactone with a 4-cyano-1-methylpyridinium methylene group and then attaching an electron-withdrawing NADH-sensing methylquinolinium acceptor via a vinyl bond linkage to the coumarin dye at the 4-position. The probe exhibits primary absorption maxima at 603, 428, and 361 nm, and fluoresces weakly at 703 nm. The addition of NAD(P)H results in a significant blue shift in the fluorescence peak from 703 to 670 nm, accompanied by a substantial increase in fluorescence intensity. This spectral shift is attributed to the transformation from an A-π-A-π-D configuration to a D-π-A-π-D pyridinium platform in probe AH, owing to the addition of a hydride from NADH to the electron-accepting quinolinium acceptor producing the electron-contributing 1-methyl-1,4-dihydroquinoline donor in probe AH. This conclusion is supported by theoretical calculations. The probe was utilized to investigate NAD(P)H dynamics under various conditions. In HeLa cells, treatment with glucose or maltose resulted in a substantial elevation in near-infrared emission intensity, suggesting increased NAD(P)H levels. Chemotherapeutic agents including cisplatin and fludarabine at concentrations of 5, 10, and 20 μM brought about a dose-dependent increase in emission intensity, reflecting heightened NAD(P)H levels due to drug-induced stress and cellular damage. In vivo experiments with hatched, starved Drosophila melanogaster larvae were also conducted. The results showed a clear relationship between emission intensity and the levels of NADH, glucose, and oxaliplatin, confirming that the probe can detect variations in NAD(P)H levels in a living organism. Our investigation also demonstrates that NAD(P)H levels are significantly elevated in the cystic kidneys of ADPKD mouse models and human patients, indicating substantial metabolic alterations associated with the disease. This near-infrared emissive probe offers a highly sensitive and specific method for monitoring NAD(P)H levels across cellular, tissue and whole-organism systems. The ability to detect NAD(P)H variations in reaction to varying stimuli, including nutrient availability and chemotherapeutic stress, underscores its potential as a valuable resource for biomedical research and therapeutic monitoring.

Epithelial tissue forms a barrier around the human body and visceral organs, providing protection, permeation, sensation, and secretion. It is vital for our sustenance as it protects the tissue from harm and injury by restricting the entry of foreign bodies inside. Furthermore, it is a strong barrier to drugs, nutrients, and other essential deliverables. This layer also houses a large consortium of microbes, which thrive in tandem with human tissue, providing several health benefits. Moreover, the complex interplay of the microbiome with the barrier tissue is poorly understood. Therefore, replicating these barrier tissues on microdevices to generate physiological and pathophysiological models has been a huge interest for researchers over the last few decades. The artificially engineered reconstruction of these epithelial cellular barriers on microdevices could help underpin the host-microbe interaction, generating a physiological understanding of the tissue, tissue remodeling, receptor-based selective diffusion, drug testing, and others. In addition, these devices could reduce the burden of animal sacrifices for similar research and minimize the failure rate in drug discovery due to the use of primary human cells and others. This review discusses the nature of the epithelial barrier at different tissue sites, the recent developments in creating engineered barrier models, and their applications in pathophysiology, host-microbe interactions, drug discovery, and cytotoxicity. The review aims to provide know-how and knowledge behind engineered epithelial barrier tissue to bioengineers, biotechnologists, and scientists in allied fields.

This work aims to fabricate the water-based suspension of poly(butylene succinate-co-adipate) (PBSA) particles by an oil-in-water emulsion technique for use as coating agents to enhance paper-based packaging performances and sustainability. A commercial PBSA resin is functionalized by sizing down an approach via microwave-assisted alcoholysis using propylene glycol (PG). The effect of PBSA/PG feed ratio on the structures, properties, and particle formability of the alcoholized (aPBSA) products is examined. ¹H NMR results reveal that the average molecular weight of the aPBSA product decreases to half that of neat PBSA when using a ratio of 24:1 and further decreases to a quarter at 6:1. By using small-size aPBSA, the obtained water-based particles show high stability due to high hydroxyl content and poly(vinyl alcohol) assistance. The suspension is then sprayed on a kraft paper substrate and heated at 60 and 100 °C. SEM results reveal that the submicron aPBSA particles penetrate the paper matrix, filling the paper's pores and forming a protective, smooth layer on the paper surfaces. The coated paper shows high water resistance (Cobb₆₀ value of 19.6 g/m²) and water vapor transmission rate (1160 g/(m² day)). In addition, the aPBSA-coated layers do not impede the paper's repulping and recycling processes, making it a promising solution for improving the sustainability of paper-based packaging.

Living systems have some of the most sophisticated reaction circuits in the world, realizing many incredibly complex functions through a variety of simple molecular reactions, in which the most notable feature that distinguishes them from artificial molecular reaction networks is the precise control of reaction times and programmable expression. Here, we exploit the hydrolysis-directed nature of λ exonuclease and the programmed responses of the dynamic nanotechnology of nucleic acids to construct a simple, complete, and powerful set of temporally programmed circuits. This system can arbitrarily regulate the degradation rate of the blocker, thereby delaying the nucleic acid chain substitution reaction with less signal leakage. In addition, the powerful dynamic reaction network of nucleic acids enabled us to control the programmed execution of a wide range of reactions in different fields. We have developed a simple strategy to introduce precise control of the time dimension into nucleic acid reaction circuits, which greatly enriches the functionality and applicability of the reaction programs, which can be easily used as timers, compilers, converters, etc. The simplicity, precision, stability, and versatility of such dynamic temporal programming circuits greatly expand the potential of artificial molecular reaction networks for more complex practical applications in biochemistry and molecular biology.

The growing threat of bacterial resistance is a critical global health concern, necessitating the development of more efficient methods for evaluating antimicrobial efficacy. Here, we introduce a technique based on the sensitivity of bacterial collective motion to environmental changes, using motion trajectory analysis for swift antibiotic susceptibility appraisal within a simple spread-out of bacterial droplet. By single cell tracking in bacterial fluids near the droplet edge or boundary-detection of the colony expansion, we achieved rapid evaluation of antibiotic efficacy in under 60 min. This method is not only faster than traditional assays but also provides insights into drug-bacterial interactions, offering a powerful tool for advancing both diagnostic testing and the development of antimicrobial agents.

Antibiotic misuse and bacterial resistance are pressing issues threatening public health. Natural plant extracts with bactericidal properties offer potential alternatives to reduce or replace antibiotic use. This study aims to develop a thermosensitive hydrogel containing daphnetin (DAP-TG) using poloxamers 407 (P407), polyvinylpyrrolidone (PVP), and poloxamers 188 (P188). We systematically evaluated the gel's antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as well as its antibacterial mechanisms. By examining the gelation temperature and time, degradation time, and in vitro release performance of DAP-TG, we produced a sustained-release DAP-TG with a rapid phase transition at (31.6 ± 0.1) °C. Its structure was characterized through Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The results indicated that the DAP thermosensitive hydrogel was formed and presented a 3D network spatial structure. The biocompatibility of DAP-TG was explored through the hemolysis test and cytotoxicity test. The results indicated that DAP-TG possessed excellent biocompatibility. The antibacterial efficacy of DAP-TG against E. coli and S. aureus was assessed using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), growth curve, and inhibition zone tests. Results showed that DAP-TG exhibited excellent antibacterial activity against both E. coli and S. aureus, with MIC values of 1.28 and 0.32 mg/mL. The antibacterial mechanism of DAP-TG was preliminarily explored through the investigation of bacterial cell content leakage, AKP leakage, membrane permeability, SEM, ROS production, and biofilm inhibition activity. DAP-TG induced irreversible damage to the cell membranes of E. coli and S. aureus, resulting in enhanced permeability, elevated ROS levels, and inhibited biofilm formation. Our study indicates that DAP-TG exhibits effective sustained-release and antibacterial properties against E. coli and S. aureus in vitro, making it a promising candidate for antibacterial applications in food and pharmaceutical products.

COVID-19 has become one of the deadliest epidemics in the past years. In efforts to combat the deadly disease besides vaccines, drug therapies, and facemasks, significant focus has been on designing specific methods for the sensitive and accurate detection of SARS-CoV-2. Of these, surface-enhanced Raman scattering (SERS) is an attractive analytical tool for the identification of SARS-CoV-2. SERS is the phenomenon of enhancement of Raman intensity signals from molecular analytes anchored onto the surfaces of roughened plasmonic nanomaterials. This work gives an updated summary of plasmonic gold nanomaterials (AuNMs) and silver nanomaterials (AgNMs)-based SERS technologies to identify SARS-CoV-2. Due to extreme "hot spots" promoting higher electromagnetic fields on their surfaces, different shapes of AuNMs and AgNMs combined with Raman probes have been reviewed for enhancing Raman signals of probe molecules for quantifying the virus. It also reviews progress made recently in the design of certain specific Raman probe molecules capable of imparting characteristic SERS response/tags for SARS-CoV-2 detection.

Blue-emissive nitrogen-doped chiral carbon dots (d-NCD230 and l-NCD230) exhibiting antipodal chiroptical activity, synthesized from the thermal pyrolysis of citric acid and d/l-aspartic acid in 1:2 molar ratios, have been explored as chirality-based fluorescent turn-off/on probes for the detection of Hg²⁺ and l-cysteine (l-Cys). Circular dichroism (CD) spectroscopy revealed that the chiroptical activity originates from a synergy among intrinsic chirality, chiral precursors on the NCD surface, and hybridization of lower energy levels within the embedded chiral chromophore. Quantitative analysis of optical asymmetry using the Kuhn asymmetry factor (g) at the CD signal of 312 nm showed a higher value for d-NCD230 (1.03 × 10^-4) compared to l-NCD230 (1.13 × 10^-5). Moreover, we have demonstrated chirality transfer and chiral inversion phenomena in d/l-NCDs by preparing carbon dots with different precursor ratios at different temperatures and probing them through CD spectroscopy. The NCDs exhibited selective fluorescence quenching in the presence of Hg²⁺, demonstrating linearity in the Stern-Volmer plot. Limits of detection (LODs) for Hg²⁺ were calculated to be 129 and 192 nM for d-NCD230 and l-NCD230, respectively, in the 0-150 μM concentration range. The quenching mechanism involves nonradiative electron transfer due to Hg²⁺ binding to oxygen-rich functional groups on the d/l-NCD230 surface. The slight variation in LOD values between d-NCD230 and l-NCD230 indicates the negligible effect of the chirality on Hg²⁺ sensing. Notably, the fluorescence intensity of d/l-NCD230 could be restored upon adding l-cysteine, with d-NCD230 showing a more pronounced enhancement than l-NCD230. This differential response is attributed to a preferential stereoselective interaction arising from the homochirality of d-NCD230/Hg²⁺ and l-cysteine. These findings demonstrate the potential of chiral nitrogen-doped carbon dots as sensitive and selective probes for Hg²⁺ and l-cysteine, with implications for environmental monitoring and biological sensing applications.

As the core component of microbial fuel cells, the conductivity and biocompatibility of anode are hard to achieve simultaneously but significantly influence the power generation performance and the overall cost of microbial fuel cells. Stainless steel felt has a low price and high conductivity, making it a potential anode for the large-scale application of microbial fuel cells. However, its poor biocompatibility limits its application. This study provides a one-step binder-free modification method of a stainless steel felt anode with reduced graphene oxide to retain the high conductivity while greatly improving biocompatibility. The maximum power density achieved by reduced graphene oxide modified stainless steel felt was 951.89 mW/m², 5.49 and 1.91 times higher than the unmodified stainless steel felt anode and reduced graphene oxide coated stainless steel felt by Nafion, respectively. The robust reduced graphene oxide modification markedly improved the biocompatibility by forming a uniform biofilm and utilizing the high conductivity of reduced graphene oxide to enhance the charge transfer rate. It led to 92.7 and 37.9% decreases in charge transfer resistance of reduced graphene oxide modified stainless steel felt compared to the unmodified one and the anode modified with reduced graphene oxide by Nafion, respectively. The excellent performance and green synthesis method of the anode validated its potential as a high-performance anode material for scaled-up microbial fuel cell applications.