ACS Applied Bio Materials最新文献

Spinal cord interfaces hold promise in restoring motor function following spinal cord injury (SCI), yet current designs face trade-offs between the degree of invasiveness and interfacial impedance. Here, we present a magnetically actuated robotic spinal cord probe (RSCP) composed of a composite material combining MXene (Ti₃C₂T_x) with Poly(2,3-dihydrothieno-1,4-dioxin)-poly(styrenesulfonate) (PEDOT:PSS), referred to as MxP. This interface is integrated with a magnetic elastomer (ME) substrate to enable soft, remote, and minimally invasive actuation and positioning. We demonstrate that magnetic actuation achieves >5 mm deflection with modest fields (∼100 mT), sufficient to conform to spinal cord anatomy. Impedance measurements using a tissue-mimicking phantom reveal that magnetic positioning significantly reduces interfacial impedance by up to 27% within the biologically relevant frequency range (5–5000 Hz) for stimulation and recording. Furthermore, the MxP electrodes demonstrate superior electrochemical stability over 21 days in phosphate-buffered saline than its MXene counterpart. Stereotaxic implantation of the RSCP’s in mice followed by immunohistochemistry analysis revealed minimal gliosis and microglial activation over 3 weeks, confirming in vivo biocompatibility. This work presents magnetically actuated RSCP’s as a potential solution to the invasiveness-impedance trade-off in spinal cord interfaces, establishing a foundation for improved therapeutic outcomes in SCI treatment.

Mycobacterium tuberculosis (Mtb) remains a major global health threat, intensified by multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains. We synthesized a series of N-benzoyl-arylthiourea derivatives (IITKDA1–20) as hybrids of isoniazid/pyrazinamide and ethionamide to explore their antimycobacterial potential. Our evaluation of synthesized library members for antimycobacterial activity has identified IITKDA10 (N-benzoyl-arylthiourea possessing p-(N-Boc)-thionamide) as the maximally effective inhibitor of Mtb (1 μg/mL MIC). Further, the physicochemical properties indicated a trend of high topological polar surface area (tPSA) and partition coefficient (ClogP) in the range of 3–4 was optimal for the compounds to be active against Mtb. Molecular docking of IITKDA10 into the InhA (enoyl-[acyl-carrier-protein] reductase) active site revealed strong binding (−9.63 kcal/mol), stabilized by hydrogen bonds and π-alkyl interactions. Further, crystal packing analysis indicated that hydrogen bonding networks guided supramolecular architecture, and structural planarity (e.g., IITKDA4, IITKDA8) correlated with higher activity. In contrast, twisted or L-shaped conformations (IITKDA2, IITKDA5) showed reduced potency. This study presents a structurally and functionally diverse set of N-benzoyl-arylthioureas with promising anti-TB activity, supported by structure–activity relationships, docking, and crystallographic insights.

Ferroptosis, an iron-dependent form of regulated cell death characterized by lipid peroxidation and redox imbalance, has emerged as a promising strategy for treating drug-resistant cancers. However, its therapeutic efficacy is often limited by the antioxidant-rich tumor microenvironment (TME), which inhibits reactive oxygen species (ROS) accumulation. In this study, we introduced a tumor-responsive nanoplatform (MLCT) designed to synergistically amplify ferroptosis through a combination of iron catalysis, calcium overload, nitric oxide (NO) release, and photothermal stimulation. The MLCT platform consisted of mesoporous polydopamine (MPDA), calcium peroxide (CaO₂), l-arginine (LA), and a tannic acid-Fe³⁺ (TA-Fe) shell, facilitating TME-responsive release of therapeutic agents. In vitro, MLCT effectively depleted glutathione (GSH) and sustained NO generation, resulting in elevated ROS levels and mitochondrial dysfunction. Additionally, upon near-infrared (NIR) irradiation, localized hyperthermia further potentiated ferroptotic activity. In vivo, MLCT combined with NIR treatment resulted in an 86.34% reduction in tumor growth, with minimal systemic toxicity. These results highlighted the potential of MLCT as a precision-engineered ferroptosis platform for enhanced cancer therapy.

Carbon quantum dots, are characterized by their exceptional fluorescence properties, low toxicity, and broad potential in biological applications and bionanotechnology. In this study, carbon dots derived from Bletilla striata (BS-CDs) were synthesized to investigate their antioxidant activity, stability, and their effects on the growth of mung bean sprouts. The results showed that BS-CDs possess remarkable antioxidant properties and excellent stability. At lower concentrations, BS-CDs significantly promoted plant growth, whereas higher concentrations exerted inhibitory effects. The optimal concentration for growth enhancement was determined to be 0.4 mg/mL (an increase of 36.4% compared to the deionized water control group). These findings highlight the potential of BS-CDs as innovative agricultural supplements, leveraging their antioxidant activity and concentration-dependent effects to improve plant growth.

Acute open wounds are susceptible to hemorrhage and infection if not treated quickly and effectively. Unfortunately, most primary wound care treatment strategies lack the ability to deliver therapeutics into the wound volume with temporal and spatial stability. Existing technologies generally only perform one function (i.e., reduce bleeding), forcing first responders to rely on a series of time-consuming prehospital treatments in resource-limited situations. To overcome these challenges, we developed and evaluated a vancomycin- and tranexamic acid-loaded biopolymer-based medical foam (MF) composed of carboxymethyl cellulose (CMC). The medical foam’s physical characteristics, cytocompatibility, antifibrinolytic efficacy, and antimicrobial activity were evaluated to demonstrate in vitro feasibility and scientific validation data with experimentation. The MF exhibited rapid expansion (3.23× initial volume) and sustained structural stability (26.5 min) in vitro. When applied ex vivo, the foam significantly reduced bacterial load (>99%) and decreased blood loss by 87.5% compared to controls. These data support the foam’s potential to spatially and temporally fill irregular wound cavities, stabilize clot formation, and provide infection prophylaxis in austere or resource-limited environments. Results demonstrated that the MF is both safe to human tissues in vitro and effective at delivering hemostatic and antibiotic agents topically.

Coordination compounds were synthesized and structurally characterized containing biocompatible alkaline earth metal ions and the bone-seeking agents clodronate (CLOD, (dichloromethanediyl)bis(phosphonate)) and medronate (MED, methylenediphosphonate). Dimensionality in these structures ranges from 0D (Mg-CLOD, Ca-CLOD) to 1D (Ca-CLOD-CP) to 2D (Ca-MED, Sr-CLOD). The salt Na₂–CLOD (used as a reference) and the CLOD coordination compounds with Mg²⁺, Ca²⁺, and Sr²⁺ were utilized as controlled release systems (excipient-containing tablets) of the active drug CLOD in acidic conditions that mimic the human stomach (pH = 1.3). Release of Ca²⁺ ions from the Ca-CLOD system was also monitored. The same experiments were carried out for the MED and Ca-MED systems. The drug release profiles were compared, and it was found that all Mg/Ca/Sr-containing compounds exhibit variable deceleration of the “active” CLOD release compared to the Na-containing reference. The calculated initial rates (μmol CLOD/min) followed the order Na (1.67) > Mg (1.32) > Sr (0.97) > Ca (0.81/0.70). The values were 1.44 and 0.57 for the MED and Ca-MED systems. This behavior was rationalized based on the structural idiosyncrasies of each system. The overall drug release profile for each system was the result of several structural factors, such as H-bonding interactions, strength of the metal–O(phosphonate) bonds, and packing density, but also crystal morphological/textural factors. These compounds were also tested for their toxicity at the concentration of 100 μM in vitro (micronucleus assay) and in vivo (brine shrimp Artemia salina) and were found to be of low toxicity.

Morphine-induced analgesic tolerance limits its clinical use. This study shows that metformin alleviates such tolerance by inhibiting the TXNIP/NLRP3/GSDMD axis, reducing microglial activation and proinflammatory cytokines in CD-1 mice (metformin 200 mg/kg i.p.; morphine 10 mg/kg s.c.) and BV-2 cells (metformin 100 μM; morphine 200 μM). TXNIP is critical, as its overexpression weakens metformin’s effect. The TXNIP siRNA/metformin coloaded TM@ZIF-8/HA nanosystem enhances efficacy via pH-responsive, CD44-targeted delivery with good biocompatibility, providing a perioperative pain management strategy.

Nature serves as an inexhaustible source of inspiration for advanced material design. While nature-inspired nonliving materials exhibit exceptional properties, they typically lack the dynamic functionalities of living systems, such as self-healing and environmental responsiveness. To bridge this gap, living materials, which integrate living cells (e.g., bacteria, fungi, algae) within abiotic matrices, have emerged as transformative platforms. These materials harness cellular functions (e.g., biomineralization, programmable metabolism) to achieve unprecedented adaptability and sustainability. In this review, we categorized living materials into two distinct types based on the role of the cells: (1) cells acting as platforms for material synthesis and (2) cells integrated as components of materials for functionalization. We summarized the characteristics of living and nonliving materials inspired by nature, with applications of living materials in energy, medicine, catalysis, concrete, and soft robotics. We further discussed advanced manufacturing techniques for living materials. We envision that the design principles of living materials will advance health, energy, and sustainability.

Cardiovascular disease (CVD) remains the leading cause of death worldwide, with small-diameter vascular grafts (SDVGs, less than 6 mm) presenting significant clinical challenges due to high failure rates from thrombosis, intimal hyperplasia, and compliance mismatch. Vascular tissue engineering (VTE) seeks to address these limitations by developing biocompatible, mechanically robust scaffolds that closely mimic native blood vessels. In this study, we focused on the fabrication and characterization of co-electrospun nanofibers composed of varying weight ratios of polyethylene terephthalate (PET) and polyurethane (PU). The structural analysis using field emission scanning electron microscopy (FE-SEM) revealed that all scaffolds exhibited uniformly distributed, bead-free, and randomly oriented fibers, except for the PET/PU (50:50) and (75:25) scaffolds, which presented a few beads. PET/PU nanofibrous scaffolds exhibited significantly smaller fiber diameters compared to pure scaffolds. Porosity percentage varied from 63.00 ± 0.46% for pure PU to 82.00 ± 2.1% for PET/PU (90:10), aligning well with the optimal range for cell proliferation. Fourier transform infrared spectroscopy (FTIR) confirmed the successful co-electrospinning of PET and PU, as evidenced by characteristic peaks consistently present across all composite scaffolds. Mechanical properties of PET/PU (75:25) and (25:75) as optimal composites achieve tensile strengths of 5.4 ± 0.69 and 4.73 ± 0.31 MPa and Young’s moduli of 44.4 ± 1.08 and 49.07 ± 1.59 MPa, closely approximating native vascular tissue properties. Burst pressure demonstrated that composite scaffolds containing more than 50% PET exceeded the clinically relevant threshold of 2000 mmHg. Compliance values were modulated by the PU content, with increasing PU proportions enhancing compliance, ranging from 5.04 ± 0.78% in PET/PU (90:10) to 8.84 ± 0.1% in PET/PU (10:90), thereby illustrating the tunable mechanical response attainable through polymer composite engineering. Biocompatibility assays confirmed significant NIH/3T3 cell viability increases on all scaffolds, notably a 3.8 time rise on PET/PU (25:75) nanofibrous composites by day 7, with preserved healthy cell morphology. In vivo assessments via rat and sheep carotid artery implantation demonstrated moderate, controlled inflammatory responses, effective tissue integration, and high long-term patency without thrombosis or hyperplasia up to 8 months, verified by histopathology and Doppler ultrasound. These results validate that co-electrospun PET/PU scaffolds, particularly at (75:25) and (25:75) ratios, exhibit a favorable combination of structural, mechanical, and biological properties suitable for SDVG applications.

Conventional dexamethasone eye drops suffer from poor ocular bioavailability due to rapid tear turnover and limited corneal residence, necessitating frequent dosing and posing challenges in chronic ocular therapies. This study addresses the need for a sustained and biocompatible ocular delivery platform by engineering hydrogel contact lenses incorporating dual-surfactant micelles for prolonged dexamethasone release. Micelles were prepared using Pluronic P123 and TPGS at different weight ratios, with a total surfactant concentration of 0.1% w/v─ten times above their critical micelle concentration─to optimize drug solubilization and encapsulation. DLS confirmed nanoscale micelles (∼11–14 nm) with a narrow size distribution. Compared to conventional soaking and single-surfactant systems, mixed micelle-laden lenses achieved significantly higher drug loading (59.1  ±  11.5 μg), minimized leaching during sterilization, and reduced burst release. In vitro release extended over 96 h with sustained flux. In vivo studies in rabbits demonstrated a >20-fold improvement in bioavailability (AUC_0–24 = 579 μg·h/mL) and extended mean residence time (8.8 h) compared to eye drops, maintaining therapeutic tear concentrations for 24 h postapplication. The formulation also suppressed inflammatory IL-6 levels to near baseline, outperforming eye drops and soaked lenses. Cytotoxicity (96.3% viability) and ocular irritation tests confirmed excellent biocompatibility. In conclusion, this dual-surfactant micelle platform markedly enhances the therapeutic potential of drug-eluting contact lenses, offering a safe, sustained, and patient-compliant alternative for managing ocular inflammation. These findings support further clinical translation of micelle-integrated lenses as next-generation ocular drug delivery systems.