ACS Applied Bio Materials最新文献

Polysaccharides are valuable building blocks for constructing functional hydrogel materials for diverse applications. Although many polysaccharides with high water solubility require cross-linking to be formulated into hydrogels, physically cross-linking ionic polysaccharides with biocompatible substances under mild aqueous conditions remains a significant challenge. Herein, we report the physical cross-linking of hyaluronic acid with crystalline cello-oligosaccharides via bottom-up coassembly at the molecular level. Neutralization of alkaline mixtures of cello-oligosaccharides and hyaluronate resulted in the facile preparation of translucent hydrogels with equilibrium moduli of 1-10 Pa. Structural analyses suggested that hyaluronate formed the backbone of the gel networks, while crystalline cello-oligosaccharides acted as physical cross-linkers. In vitro cytotoxicity assays demonstrated the excellent cytocompatibility of the coassembled hydrogels. Furthermore, the cationic antibiotic polymyxin B was successfully incorporated into the hydrogels, yielding antibacterial composite hydrogels. This study provides a promising strategy for the development of advanced polysaccharide-based biomaterials through physical cross-linking with crystalline oligosaccharides.

The development of fully biodegradable piezoelectric nanogenerators (PENGs) is gaining attention as self-powered implantable and wearable technologies demand energy-harvesting materials that are both eco-friendly and high performing. Silk fibroin (SF) has emerged as a promising bioderived candidate due to its mechanical robustness and biocompatibility; however, its intrinsic piezoelectric output remains limited. This work produces a structurally reinforced silk fibroin (SRSF) biocomposite film, fabricated by incorporating MXene multilayers into the SF matrix, followed by alcohol treatments to induce β-sheet crystallinity, dipole orientation, and interfacial integrity. The fabricated SRSF-PENG device delivered a maximum output voltage of 14.8 V, current of 0.88 μA, and power density of 80.4 μW cm^-3. Recycling studies confirmed that the regenerated device retained nearly 87.8% of its original piezoelectric performance, demonstrating excellent reproducibility. Soil-burial biodegradation tests revealed a rapid decomposition rate exceeding 4.2% week^-1 across a 12 week period. Additionally, environmental stability analyses showed that the SRSF biocomposite film maintained a comparable voltage output under high-humidity (70% RH) and fully underwater conditions, indicating effective MXene protection by the hydrophobic SF network. These findings position SRSF as a sustainable, durable, and high-efficiency material platform for next-generation, self-powered bioelectronic systems.

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.