ACS Applied Bio Materials最新文献

To address the global public health challenge of bacterial infections, this study developed a broadband-responsive nanoantibacterial composite material named TAB AZO-GA-MXene (TAGM). The material was prepared by electrostatically loading cationic azobenzene quaternary ammonium salts onto the surface of the two-dimensional nanomaterial MXene, with gum Arabic (GA) used as a dispersant. The antibacterial properties of the composite material exhibit distinct variations following irradiation across a broad spectrum of light, including ultraviolet, visible, and near-infrared wavelengths. TAGM combines the physical shearing and photothermal effects of MXene with the membrane-disrupting and DNA-damaging capabilities of azobenzene quaternary ammonium salts, thereby establishing a multimechanism synergistic antibacterial platform. Experimental results show that the Trans form of TAGM demonstrates stronger bactericidal activity against E. coli under green light, whereas the Cis form exhibits better inhibitory activity against S. aureus under ultraviolet light. Under corresponding illumination conditions, TAGM achieved bacterial inactivation rates of 99.11% against E. coli and 99.81% against S. aureus, indicating rapid and highly efficient antimicrobial performance. This study not only broadens the spectral response range of light-responsive antibacterial materials but also provides a strategy for developing selective, multimechanism synergistic antibacterial systems, showing promising potential for combating multidrug-resistant bacterial infections.

Sensitive skin caused by environmental and seasonal factors has become a global issue, and daily skin care can help alleviate symptoms through gentle formulations with effective ingredients. This study aimed to develop and evaluate a multifunctional lotus-leaf-extract-based nanoformulation for sensitive skin care, integrating whitening, barrier restoration, and moisturizing effects. The cream was structurally characterized as an oil-in-water (O/W) emulsion through oil/water dilution, cobalt chloride paper impregnation, and microscopic analyses, which collectively confirmed its O/W structure. Rheological testing and stability analysis revealed pseudoplastic behavior with low viscosity, ensuring rapid absorption and minimal residue, while maintaining stability and robustness under extreme temperatures (−20 to 45 °C, 72 h) and centrifugation (3000 rpm for 30 min). Functional assessments demonstrated strong antioxidant activity (71.01% DPPH scavenging at 0.10 g mL^–1) and sustained moisturization (65.23% retention over 24 h), along with broad-spectrum UV absorbance (280–400 nm) indicating photoprotective potential comparable to standard UV filters. Safety profiling confirmed biological compatibility through pH testing and antimicrobial efficacy against E. coli and S. aureus and showed mild irritation in CAM assays, with an ES score of 3.0 indicating a mild level of irritation. Mechanistically, the formulation acts via synergistic antioxidant and anti-inflammatory pathways to mitigate oxidative stress, restore epidermal barrier integrity, and suppress melanogenesis, and these mechanistic insights are inferred from the literature evidence rather than direct in vitro or in vivo experiments. Overall, these findings highlight the lotus-leaf-extract-based nanoformulation as a dual-action therapeutic strategy for sensitive skin, effectively combining whitening efficacy with barrier repair.

This study presents an approach to the synthesis of nanocomposite magnetic hydrogel microbeads using a microfluidic-assisted droplet method followed by in situ gelation in a heated oil column. The beads were fabricated from a semi-interpenetrating polymer network (semi-IPN) comprising gelatin, and vinylic monomers, with incorporation of iron oxide nanoparticles (Fe₃O₄) synthesized via coprecipitation. The unique combination of pressure-mediated bead formation and controlled gelation kinetics enabled tunable porosity, as validated through SEM and pore size distribution analysis, where increased oil column height yielded narrower pore distributions due to enhanced gelation. Magnetic characterization confirmed strong superparamagnetic behavior, while FTIR and XRD analyses verified successful chemical integration of the polymeric and nanoparticle components. Rheological studies revealed enhanced elasticity and network strength in nanoparticle-loaded hydrogels, and swelling/deswelling tests, fitted with first-order and exponential decay models, demonstrated reversible, magnetically tunable water uptake. Furthermore, in vitro cell culture studies showed excellent cell attachment and proliferation on the bead surface, facilitated by the porous, wrinkled morphology. Collectively, these multifunctional beads exhibit significant promise for applications in cell delivery, magnetically guided therapies, and responsive tissue engineering platforms.

The use of silver nanoparticles (AgNPs) in biomedical and household products has rapidly increased in recent years. However, the long-term effects of these AgNPs on human health are poorly understood. In this study, AgNPs of approximately the same size were prepared with different surface functionalizations, namely, tyrosine (Tyr), curcumin (Cur), and epigallocatechin-3-gallate (EGCG). These were used to determine the acute and chronic toxicity on human cells, as well as the effects on oxidative stress, cell adhesion, and cell cycle progression. Additionally, we assessed cell recovery after 24 h of exposure and the effect of intermittent AgNP exposure on successive cell passages. The results indicate that Tyr-AgNPs showed negligible acute toxicity in cells but had the highest chronic toxicity profile. The cells took up to four passages to recover after 24 h of exposure to these NPs, most likely due to the generation of metal ions from the AgNPs. Meanwhile, Cur-AgNPs showed the lowest chronic toxicity. Since curcumin and EGCG molecules have more phenolic groups available than tyrosine, they provide better surface coverage of AgNPs, thereby reducing some of the toxic effects. Therefore, the findings from this study suggest that the bioactive surface coating on AgNPs plays a vital role in influencing their biocompatibility and might mitigate some of their long-term effects on human cells.

In order to address the rapid degradation of biomedical magnesium alloy implants in corrosive media, this study employed a surface modification approach. After fluorination pretreatment of AZ31 magnesium alloy, a silicon (Si) thin film was uniformly deposited on the surface using magnetron sputtering, aiming to enhance the corrosion resistance and biocompatibility of the AZ31 alloy. The corrosion behavior of both coated and uncoated samples in simulated body fluid (SBF) was evaluated through electrochemical tests. Additionally, cytotoxicity and hemocompatibility were assessed using CCK-8 and hemolysis assays, respectively. The results indicate that, compared with the bare magnesium alloy substrate and the magnesium alloy coated with a single sputtered Si thin film, the Si thin film deposited on the fluorinated magnesium alloy substrate exhibits a lower corrosion current density, as well as higher charge transfer resistance, phase angle, and impedance modulus. In addition, the fluorinated Si-coated sample shows lower cytotoxicity. These findings indicate that the combination of fluorination pretreatment and magnetron-sputtered Si thin films is an effective approach for enhancing the early stage corrosion resistance and initial biocompatibility of AZ31 magnesium alloys, providing a promising surface engineering strategy for further investigation.

Accurate and selective recognition of ions and molecules is crucial in medical and diagnostic research. Cu(II)- and Zn(II)-based coordination polymers (CPs) have been designed in this work to detect trace levels of melatonin and tryptophan and evaluate their anticancer activity. The [Cu₂(4-bph)₂(adc)₄]_n (CP1) (4-bph = (1E,2E)-1,2-bis(pyridin-4-ylmethylene) hydrazine; Hadc = 1-adamantanecarboxylic acid) structure shows that 4-bph serves as a bridging pyridyl-N ligand and adc^– is a chelating and binuclear bridging ligand, forming an eight-membered Cu(μ-COO)₂Cu motif. In Zn(II)-CP, 4-bph is a bridging ligand, while adc^– is monodentate, yielding [Zn(4-bph)(adc)₂]_n (CP2). In CP1, π–π stacking (∼3.875 Å) and hydrogen bonding generate a 3D supramolecular network while CP2 forms pyridyl-N bridging zigzag 1D CP. The BET analysis measures higher pore volume of CP1 (0.06 cm³ g^–1) than CP2 (0.018 cm³ g^–1). The CP1 is weakly emissive, and upon irradiation at 312 nm, it emits at 392 nm which has been enhanced by the addition of tryptophan (Trp) (LOD, 44.65 nM), in the presence of 19 other amino acids. The CP1 senses melatonin (MEL) (LOD, 38 nM) also in the presence of various proteins, enzymes, and neuroactive metal ions. Blood serum is used for the measurement of melatonin in blood serum (pH 7.4) and also tryptophan measurement in milk. The CP2 is inactive toward sensing performance. DFT computation using crystallographic parameters reveals a stronger binding of CP1 with Trp (−221 kcal mol^–1) than that of CP2 (−38.22 kcal mol^–1). Anticancer assays show that CP1 is more potent than CP2 against MCF-7 breast cancer cells, IC₅₀ values are 196.8 ± 2.31 nM (CP1) and 258.2 ± 2.08 nM (CP2). Both CPs exhibit minimal toxicity toward normal PBMCs at these doses. Theoretical evaluation has also been used to explain the luminescence and selective sensing behavior to Trp and MEL.

Postoperative infection remains a significant challenge in surgery, often hindering healing. This study aims to design a near-infrared (NIR)–responsive, disulfide-functionalized bioactive metal–organic framework (Bio-Zn@S-MOF) made of zinc cations, adenine, and 3,3′-dithiodipropionic acid (DTPA) ligands. The incorporation of DTPA introduces redox-active disulfide bonds, providing the framework with stimuli-responsive behavior and the ability to release melatonin in a controlled manner under infection-mimicking acidic and NIR-irradiated conditions. Bio-Zn@S-MOFs demonstrate strong antioxidant activity, free radical scavenging over 91.0% within 24 h, excellent cytocompatibility against MG63 and RAW 264.7 cells, and the ability to promote osteogenic differentiation, while suppressing intracellular reactive oxygen species (ROS). These frameworks exhibit remarkable in vitro bactericidal activity, which is further enhanced by NIR light irradiation. Together, these findings introduce a NIR-responsive Bio-Zn@S-MOF that integrates light-triggered bactericidal and antioxidant activities with osteogenic potential, offering a promising therapeutic strategy for infection control in bone tissue.

Developing Cu-based nanocatalysts capable of generating sufficient reactive oxygen species (ROS) to effectively inhibit tumor cell growth remains a significant challenge. In this study, we introduce a distinctive copper oxide nanocarrier with a unique leaf-like lamina structure and layered mesopores. Indocyanine Green (ICG) is encapsulated within the mesopores, and poly(ethylene glycol) (PEG) groups are attached to the surface. This nanoplatform demonstrates efficient accumulation in tumor areas, serving as a near-infrared (NIR) fluorescent contrast agent for tumor imaging. Remarkably, under NIR laser irradiation, the nanoplatform exhibits high photothermal conversion efficiency, which enhances ROS production through localized heating. Both in vitro and in vivo experiments confirm that our nanoleaf structure effectively prevents tumor growth. These results underscore the potential of CuO-based nanocomposites activated by tumor microenvironment stimuli as chemodynamic nanoagents, enabling malignant cancer destruction through a synergistic effect with NIR light.

Intracellular drug therapies are based on the use of nanocarriers that can successfully penetrate cell barriers and release therapeutic payloads directly inside the cell environment. In this context, hydroxyapatite (HA) nanoparticles provide a particularly promising platform owing to their inherent biocompatibility, bioactivity, and drug-binding capability. This work hence examines anisotropic HA nanorods (NRs), synthesized using hydrothermal methods, with a particular focus on Mg-to-Ca ion substitution, aiming to increase the bioactivity and improve the interaction with therapeutics, specifically targeting intracellular sustained release. Our findings indicate that increasing the extent of Mg doping in apatite NRs induces enhanced cell compatibility and interaction with primary human bone marrow-derived mesenchymal stem cells. Moreover, the doping with Mg²⁺ enhances the NRs capacity to link and release doxorubicin, a widely used antitumor drug, in human osteosarcoma cells. The enhanced functionality is attributed to the Mg²⁺-induced structural disorder at the NR surface, which reduces the crystallinity and increases the number of reactive surface sites. As a result, Mg²⁺ doping has emerged as a promising strategy for optimizing the functional performance of apatite-based nanocarriers, highlighting their potential applications in nanomedicine and precision medicine.

Rapid and effective bleeding control is essential for saving lives from severe hemorrhage. Currently, expandable hemostatic materials are in urgent demand for narrow and deep wounds because they can be quickly packed into a wound cavity and expand internally to generate pressure that promotes hemostasis. In this work, a zeolite–poly(vinyl alcohol) (PVA) composite sponge was first prepared by decorating zeolite powders onto a commercial medical PVA sponge, and it was further fabricated into small tablets in a compressed state. The small tablets can be easily loaded inside a syringe-like applicator for rapidly injecting into deep wounds in less than 3 s, and they can quickly expand six times in less than 30 s when they come into contact with blood. This material shows outstanding hemostatic efficiency and excellent biosafety. In a New Zealand rabbit severe femoral artery hemorrhage model, the short average hemostasis time (123 s) and the small total blood loss (9.9 g) for the zeolite–PVA sponge group clearly demonstrate its outstanding hemostatic efficiency, compared to the commercial Celox sponge group (220 s and 22.9 g) and the gauze group (333 s and 28.5 g). Consequently, the timely and effective hemostasis led to a 100% survival rate for the zeolite–PVA sponge group in this severe femoral artery hemorrhage model. On the contrary, the survival rates of the gauze group and the Celox sponge group were only 67% and 83%, respectively. This rapidly expandable zeolite–PVA sponge material provides a promising solution for meeting the challenge of massive hemorrhage in narrow and deep wounds.