ACS Applied Bio Materials最新文献

Food spoilage in perishable products like chicken poses serious safety and economic challenges. Conventional packaging offers limited protection and lacks real-time freshness detection. Smart packaging using natural indicators provides an eco-friendly solution for monitoring food quality. Anthocyanins, as pH-sensitive pigments, can visually indicate spoilage, while plant-derived carbon dots (CDs) offer fluorescence, antioxidant, and antimicrobial properties. Integrating these bioactives into electroblown nanofibers enables the creation of biodegradable, responsive materials suitable for intelligent packaging applications. In this study, multifunctional electroblown nanofiber mats incorporating Consolida orientalis-derived anthocyanins (CoD) and carbon dots (CDs) were fabricated using electro-blowing technology to serve as smart indicators for monitoring the freshness of chicken fillets. CoD and CDs, derived from a single plant source, provided dual functionality, combining pH-responsiveness, antimicrobial, and antioxidant activity within a biodegradable poly(vinyl alcohol) (PVA) matrix. Physicochemical properties of the nanofibers were analyzed, including morphology (Scanning Electron Microscopy), chemical structure (Fourier Transform Infrared Spectroscopy), thermal stability (Thermogravimetric Analysis), crystallinity (X-ray Diffraction), mechanical strength, hydrophilicity, and air permeability, confirming structural integrity and suitability for packaging. Cytotoxicity assays revealed minimal toxicity, ensuring CD biocompatibility for food-contact applications. The mats showed a distinct colorimetric response to pH changes, correlating with microbial spoilage in chicken fillets stored under refrigeration. Total viable and psychrotrophic counts exceeded 7 log CFU/g by day 10, corresponding to a pH rise from 5.71 to 7.90 and a ΔE of 21.78, confirming the mats' effectiveness as real-time spoilage indicators. The integration of plant-derived bioactives and nanotechnology in these mats offers a scalable, sustainable, intelligent packaging solution, enhancing food preservation and providing consumers with real-time freshness assessment for perishable foods.

This study focuses on the synthesis of an rGO/Nd₂WO₆ nanocomposite using an environmentally friendly green approach, employing Phyllanthus amarus leaf extract. The bioactive compounds in the plant extract facilitate simultaneous reduction and stabilization of the nanocomposite, eliminating the need for harmful chemicals. The resulting nanomaterials were thoroughly characterized by using the Brunauer-Emmett-Teller technique, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and X-ray diffraction analyses to confirm their structural, morphological, and optical properties. The photocatalytic performance of rGO/Nd₂WO₆ was evaluated through the degradation of methylene blue under sunlight irradiation, achieving a degradation efficiency of 82.29%, which was significantly higher than those of WO₃ (61%) and Nd₂WO₆ (73.65%). The enhanced photocatalytic activity is attributed to the synergistic effect of rGO, which promotes efficient charge carrier separation, extended light absorption, and improved electron transport. Kinetic studies revealed a pseudo-first-order reaction mechanism, with rGO/Nd₂WO₆ exhibiting the highest rate constant (k = 0.0413 min^-1). Additionally, the nanocomposite demonstrated excellent antioxidant activity, as assessed by the DPPH radical scavenging assay and antibacterial activity. These findings underscore the use of Phyllanthus amarus extract for the sustainable synthesis of high-performance photocatalytic and antioxidant nanomaterials, positioning rGO/Nd₂WO₆ as a promising candidate for wastewater treatment, environmental remediation, and potential biomedical applications.

In an effort to discover a dual-functional and eco-friendly platform to address the challenges of halide entrapment and removal of toxic metal ions from wastewater concurrently, this work delineates a novel approach of fishing out a potential weapon compound I, from a pool of three constructs, harnessing the concept of hydrophobic orchestration. We propose that the chloride-palmitic acid derivative, formed through nucleophilic substitution of the palmitic acid's alcoholic hydroxy group, plays a crucial role in driving self-assembly, which ultimately leads to hydrogel formation and halide entrapment. Furthermore, the resulting chloride-palmitic acid derivative undergoes heavy metal ion (Pb²⁺/Cd²⁺)-induced syneresis, likely due to the formation of metal-ligand complexes under the given experimental conditions, as supported by extensive experimental evidence. This dual-responsive behavior of compound I, along with its reusability for up to three cycles, represents a promising and effective strategy for environment management.

The rapid rise of bacterial resistance has highlighted the urgent need for nonantibiotic antibacterial strategies. Herein, we report a facile one-pot synthesis of covalent organic framework nanospheres (DT-COF NS) with a uniform diameter of ∼600 nm under mild conditions. The as-prepared DT-COF NS exhibit pronounced photoactivity under visible light irradiation and generate multiple reactive oxygen species (ROS), including hydroxyl radicals (^•OH), superoxide anions (O₂^•-), singlet oxygen (¹O₂), and hydrogen peroxide (H₂O₂), via a type I photodynamic pathway. Benefiting from this efficient ROS production, the COF nanospheres achieved over 99% bactericidal efficiency against both MRSA and Escherichia coli in vitro and in vivo level. Compared with conventional DT-COF NS synthesis routes requiring harsh conditions or complex templates, our strategy offers a simple, mild, and scalable approach. These findings demonstrate the great potential of DT-COF NS as next-generation photoactive antibacterial materials, paving the way for their future applications in advanced antimicrobial systems.

Chronic wounds result in extended healing durations and increased susceptibility to infections. Wound infections pose a major obstacle to the healing process. Dressings with improved antibacterial properties should be used to treat chronic, infected wounds. In this work, carboxymethyl cellulose (CMC), poly(vinyl alcohol) (PVA), and polyvinylpyrrolidone (PVP) were used to fabricate a polymeric patch with molybdenum oxide (MoO₃) nanoparticles and naringin. Molybdenum oxide (MoO₃) nanoparticles were synthesized using the wet chemical method and characterized by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The antibacterial activity of MoO₃ was evaluated using diffusion, colony count, growth curve analysis, and biofilm disruption methods. Biocompatibility, swelling behavior, degradation rate, porosity, drug release profile, water vapor transmission rate (WVTR), and MTT and scratch assays were used to evaluate the fabricated polymer patches (CMC/PVA/PVP with and without MoO₃ and naringin). In an in vivo wound healing study, the CMC/PVA/PVP/MoO₃/naringin patch demonstrated enhanced healing, with 91% wound closure in 15 days in a full-thickness excisional wound model in Wistar rats.

Colon-targeted delivery systems offer a promising approach for local drug administration. In this study, we developed a customized polymeric blend for this purpose, combining polyethylene glycol (PEG), polycaprolactone (PCL), and hydroxypropyl methylcellulose (HPMC). Although PEG and PCL have been extensively studied, the inclusion of HPMC in such blends remains underexplored; however, its use in this context shows significant potential due to its pH sensitivity. To achieve this, various formulations were tested to optimize the thermomechanical and release characteristics of capsules produced through injection molding. Three blends containing 22, 24, and 34 wt% HPMC were processed and analyzed using rheological methods, ATR-FTIR, TGA, DSC, SEM, and in vitro release tests with methylene blue as a model compound. Simulated pH-release tests (pH 2.5, 5, and 6.8) showed minimal release in gastric and intestinal environments, with controlled and sustained release under colonic pH conditions. It was also observed that the initial HPMC content affects the release rate of the model compound. Specifically, when the blend contains 34% HPMC, approximately 38% of the compound is released within 12 h and 73% within 24 h. These results highlight the potential of pH-sensitive polymer blends as effective platforms for colon-targeted drug delivery. A model illustrating how the release rate depends on pH value and HPMC amount was also proposed and validated. The process was considered to happen in two stages: initially, the release medium penetrates the capsule and solubilizes the model compound; then, the model compound is released into the surrounding environment.

Small-diameter vascular grafts (SDVGs, <6 mm) exhibit significant potential as alternatives to coronary and peripheral arteries, yet their clinical application is hindered by thrombosis and intimal hyperplasia. A synergistic modification strategy utilizing polydopamine (PDA) and lysine (Lys) was developed to functionalize polyimide (PI) fibers, aiming to enhance the antithrombotic properties and endothelial regeneration capacity of SDVGs. Alkaline etching activates PI fibers and facilitates the formation of PDA-Lys composite coatings through Schiff base and Michael addition reactions. Characterization results demonstrate that the modified fibers exhibit significantly reduced surface roughness and enhanced hydrophilicity, while retaining high mechanical strength and thermal stability. Hemocompatibility assessments reveal that PI-PDA-Lys fibers exhibit a hemolysis rate below 3.4% and an 80% reduction in platelet adhesion relative to unmodified fibers. This performance improvement is attributed to the optimized surface charge balance and reduced surface roughness. Human umbilical vein endothelial cells (HUVECs) show high viability, sustained proliferation over 7 days, and enhanced migration toward PI-PDA-Lys scaffolds. This multifaceted surface engineering strategy effectively addresses the critical challenges of thrombosis and delayed endothelialization in SDVGs. The modified PI fibers demonstrate significant potential to serve as a viable platform for the development of advanced small-diameter vascular grafts.

Erythrocyte-derived microparticles containing near-infrared (NIR) dyes such as indocyanine green present a promising cell-based platform for optical imaging and phototherapeutics. Using real-time intravital NIR fluorescence imaging of mice vasculature, we investigated the effects of blood type, specifically O⁺ and B⁺, used in fabricating these particles, the number concentration (N_v) of the particles, and the relocalization of phosphatidylserine (PS) to the outer leaflet of the particles' membrane on the resulting circulation dynamics following a single retro-orbital injection. Additionally, we quantified the biodistribution of particles in various organs. We found that the fluorescence emission half-life for particles engineered from O⁺ blood type extended from 11.4 ± 3.0 to 43.1 ± 9.6 min with increased N_v from a low range of 0.4-0.6 to high range of 1.4-1.6 million particles/per μL, when only 30-55% of the particles demonstrated externalized PS. For these particles, the liver and gallbladder, lungs, and spleen showed similar levels of accumulation at 60 min post administration. When >90% of O⁺-particles showed PS externalization, or when the particles were fabricated from B⁺ blood type despite PS externalization in 30-55% of the particles, the emission half-life was reduced to 15.8 ± 5.9 and 18.1 ± 4.6 min, respectively. There was lower accumulation of these particles in the spleen as compared to the liver and gallbladder and the lungs. In vitro experiments demonstrated increased PS externalization correlated to a more efficient uptake of the particles by macrophages. These findings emphasize the importance of blood type, N_v, and PS in engineering erythrocyte-derived particles for future clinical applications.

Wound infection causes excessive inflammation, delays healing, and may lead to severe complications. An ideal dressing should release antibacterial agents on demand to eradicate pathogens locally. Enzyme-responsive drug release systems are highly biocompatible and specific, yet their application in chitosan hydrogels has been limited by imprecise control over release profiles, mechanical properties, and potential drug resistance from premature leakage. Herein, we developed a dual-enzymatically responsive chitosan hydrogel for the on-demand release of antibacterial nanoparticles (ANPs). By synthesizing a series of hydroxyphenyl- and N-acetyl-modified glycol chitosan (HPPA-GC), we tuned the hydrogel stiffness and lysozyme degradation kinetics. Broad-spectrum ANPs were encapsulated via photo-cross-linking. Lysozyme, abundant in infected wounds, triggered hydrogel degradation and ANP release in vitro. When applied to S. aureus-infected full-thickness wounds in mice, the ANP-loaded hydrogel effectively combated infection and accelerated healing. This study demonstrates a robust and biocompatible platform for enzyme-triggered antimicrobial delivery, showing promise for the future development of smart wound dressings.