ACS Applied Bio Materials最新文献

Cell targeting would benefit various biotechnological applications such as disease diagnosis and cancer therapy. However, efficiently functionalizing nanoparticles with targeting ligands such as antibodies remains challenging. For example, poly(acrylic acid)-modified titanium peroxide NPs (PAATiOx) have shown promising radiosensitizing effects but suffer from poor tumor accumulation due to a lack of targeting. Herein, we developed a simple, one-pot process to noncovalently graft anti-CD44 antibodies onto the surface of PAATiOx NPs using tannic acid, a polyphenol that can bind to diverse surfaces and biomolecules via multiple molecular interactions. We evaluated the cellular binding, internalization, therapeutic efficacy, and biodistribution of the targeted particles. The antibody-functionalized NPs exhibited ∼2-fold enhanced binding to CD44-expressing cells compared to unmodified NPs and enhanced cellular internalization in vitro (2.4-fold in MIAPaCa-2 cells and 6.5-fold in MDA-MB-231 cells). Additionally, the NPs maintained their radiosensitizing property, significantly inhibiting the growth of CD44-expressing cells by 2-fold compared with CD44-negative cells. In vivo biodistribution studies revealed ∼2-fold greater tumor accumulation of the targeted NPs compared to unmodified NPs (p < 0.05). This polyphenol-mediated antibody coating strategy is a versatile and broadly applicable platform for enhancing nanoparticle delivery to specific cell populations, with potential for improving radiotherapy outcomes in CD44-positive tumors.

This work presents a G-quadruplex heme chloride DNA peroxidase biosensing system. To address the instability and strong background signal issues in visual H₂O₂ detection, a G-quadruplex was prepared by using four trimeric DNA strands, and hemin was attached via covalent binding. The covalent binding significantly improved the color rendering effect and reduced the background signal. Four types of single-stranded DNA were compared for catalytic activity, with (GGGA)3 showing the best performance. The system was successfully applied to detect H₂O₂ in human serum, reaching a minimum detection concentration at the nanomolar level. This study provides valuable data for selecting single-stranded DNA in G-quadruplex preparation and holds potential for visual H₂O₂ detection in biomedicine and various industrial fields.

The combination of challenges associated with osteosarcoma treatment emerges from the inadequacy of conventional cancer therapies to heal the extensive bone defects generated following tumor excision. On the other hand, the bone-regeneration approach lacks in mitigating the risk of tumor recurrence. This therapeutic gap demands the necessity of a multifunctional approach that simultaneously inhibits cancer recurrence and promotes the process of bone regeneration. The extensively employed traditional photosensitizers display limited anticancer activity and lack regenerative properties. These constraints are circumvented through the development of a bilayer Janus hydrogel that integrates NaDyF₄@NaYF₄:Nd³⁺ nanophosphors within a poly(vinyl alcohol) (PVA) layer, while a chitosan layer encompasses functionalized alendronate and samarium. This multifunctional hydrogel, developed through a freeze-thaw process, exhibited strong photothermal activity and also demonstrated efficacy in eradicating MG63 osteosarcoma cells in vitro. Further, the typical extracellular matrix resemblance characteristic of the hydrogel demonstrated better cell proliferation and osteogenic differentiation of MG63 cells and promoted vascularization in the CAM model. Moreover, the presence of lanthanides in the hydrogel facilitates multimodal imaging characteristics of magnetic resonance imaging (MRI), computed tomography (CT), and near-infrared (NIR) luminescence. Thus, the synergistic effect of encompassing localized cancer therapy and efficient bone restoration offers a promising strategy to treat bone tumors.

Thermoresponsive hydrogels have been extensively investigated for biological applications, particularly in wound healing due to their capacity to undergo phase transitions in response to temperature changes. Natural polymers have been identified as promising candidates for hydrogel synthesis owing to their intrinsic biocompatibility, biodegradability, and hydrophilicity. In this review, the critical role of natural polymers in the development of thermoresponsive hydrogels for wound healing applications is highlighted. Wound healing is recognized as a complex, multiphase process that necessitates an optimal microenvironment to facilitate tissue regeneration while minimizing inflammation and infection. Natural polymers such as chitosan, gelatin, agarose, and cellulose derivatives have been considered ideal for wound dressings, as they provide favorable conditions for cellular adhesion and proliferation. The physicochemical properties of natural polymers, including their thermoresponsive behaviors governed by phase transition temperatures, such as the Lower Critical Solution Temperature (LCST) and Upper Critical Solution Temperature (UCST), along with their gelation mechanisms, are discussed. Recent advancements in natural polymers with enhanced thermoresponsive characteristics are examined for their improved therapeutic outcomes. To address limitations in mechanical strength and response performance, various formulation strategies, including physical and chemical cross-linking, as well as hybrid systems incorporating synthetic polymers, have been explored. Applications in wound care, such as controlled drug delivery systems and smart dressing technologies, are reviewed in detail. Finally, the challenges and future directions for clinical translation of these systems are considered. This comprehensive review underscores the potential of natural polymer-based thermoresponsive hydrogels as intelligent, bioactive platforms for accelerating wound healing and advancing regenerative medical therapies.

The emergence of two-dimensional (2D) nanomaterials such as MXenes has significantly expanded opportunities in precision oncology. With their high surface area, tunable surface chemistry, strong photothermal conversion efficiency, and intrinsic biocompatibility, MXenes offer promising potential for cancer nanotheranostics. This review explores the therapeutic applications of MXenes, focusing on their dual roles in direct tumor ablation and modulation of the tumor immune microenvironment (TIME). MXenes exert anticancer effects through reactive oxygen species-mediated cytotoxicity and localized photothermal heating while also influencing immune cell function and tumor-immune interactions. Recent studies using single-cell sequencing and high-dimensional immune profiling highlight the capacity of MXenes to modulate immune-mediated tumor cell death. Their selective reactivity in the acidic tumor milieu, linked to the Warburg effect, makes them ideal candidates for pH-responsive drug delivery. We further discuss synergistic strategies combining MXene-based photothermal therapy with chemotherapy, targeted agents, and immunotherapies. Advancing MXene-based cancer therapies requires an integrated understanding of tumor biology, metabolic reprogramming, and TIME dynamics. This multidisciplinary approach is essential for the development of safe, selective, and personalized nanomedicine platforms.

Flexible and environmentally friendly electrochromic devices (ECDs) show great application potential for active light management, such as smart color-changing windows and color-changing sunglasses. Natural cellulose, as an environmentally friendly, low-cost, and renewable material, has advanced the development of sustainable ECDs, while its hydrophilic nature leads to unstable performance, especially in humid and rainy conditions. Therefore, we presented the sandwich-structured cellulose acetate-cellulose (CA-C)/PEDOT:PSS by layer-by-layer assembly, which displays high water resistance and mechanical stability as well as a fast transmittance response to the external voltage. By applying a forward voltage of 3 V, the transmittance of the prepared electrochromic composite film quickly changes from 83% to 40%; under a backward voltage, it recovers to its initial state within 2 s. Additionally, the cellulose-based composite film also demonstrates stable electrochromic capability after 500 bending cycles or 24 h of working in an outside environment, even under high humidity. The developed CA-C/PEDOT:PSS electrochromic composite film paves the way toward advancing electrochromic materials to be more sustainable and stable in a low-carbon society.

Over the last years, stereolithography has developed to be one of the most promising fabrication techniques in tissue engineering. Posing the possibility of fabricating patient-specific, porous implants, it became especially attractive for scaffold fabrication for the treatment of critical sized bone defects. State-of-the-art photopolymer systems mostly consist of potentially cytotoxic compounds, such as (meth)acrylates, that furthermore show insufficient degradation and lead to acidic degradation products that could induce adverse tissue reactions. Herein, we introduced trifunctional monomers comprising cleavable silyl ether groups for thiol–ene photopolymerization to enlarge the material platform for printed bone grafts. Polymer networks comprising a high number of silyl ether moieties typically tend to be mechanically weak and exhibit low T_g values, especially when combined with thioether bonds, which are a direct result of polymerization via thiol–ene click reaction. To push thermomechanical properties to a level where they are sufficient for bone grafting (T_g > 37 °C), we introduced rigid bridged alicyclic structures in the form of norbornane-derived motifs into the silyl ether monomers, resulting in a norbornene-containing double bond monomer and a norbornane-derived thiol monomer. Together with noncleavable comonomers, we were able to demonstrate a substantial increase in T_g up to 62 °C, which is well above the values reported until now for similar thiol–ene networks. Furthermore, in this study, we demonstrated high photoreactivity for some of the monomers and also successfully performed proof-of-concept printing using a DLP setup. Besides excellent thermomechanical behavior, the mechanical strength of the silyl ether-based polymer network was shown to be outstanding. Cleavability of the silyl ethers was displayed with a quasi-linear degradation rate of 6.5% per month with moderate swelling. Additionally, the degradation product of the silyl ether-based network was isolated and shown to exhibit no relevant cytotoxicity to mouse fibroblast cells.

Infected wound healing is a clinical problem owing to excessive inflammatory responses. In this study, a multicomponent hydrogel GOP was prepared by employing salmon polydeoxyribonucleotide (PDRN), oxidized sodium alginate (OSA), and gelatin (Gel) as starting materials. The hydrogel with three-dimensional structure was synthesized through the Schiff-base cross-linking of PDRN, Gel, and OSA. Hydrogen bonding and electrostatic interaction also participated in the formation of the three-dimensional network. Hydrogel GOP demonstrated a good mechanical property and tissue adhesion ability. In vitro studies revealed the antibacterial activity of hydrogel GOP toward S. aureus and E. coli, along with remarkable antioxidant activity. Biocompatibility tests showed high cell viability (>80%) and good ability to promote cell migration. Hemolysis assay revealed minimal hemotoxicity (<2.1%). Using a murine full-thickness dermal injury model, GOP treatment achieved small residual wound area (2.3%) on day 14. Histological analyses demonstrated reduced inflammation cells and enhanced collagen deposition. Immunofluorescence analyses showed suppressed inflammation level (increased IL-10) and improved angiogenesis (upregulated CD31 and α-SMA). These results revealed that hydrogel GOP represented a promising multifunctional dressing for infected wound management.

Small extracellular vesicles (sEVs) are lipid nanoparticles secreted from mammalian cells that are involved in the transfer of information or therapeutically effective substances between cells. Although the scope of research on sEVs as biocompatible carriers for drug delivery to diseased tissues and cells is expanding, there is still room for improvement in the efficiency of drug loading on and in sEVs and their subsequent uptake into cells. It is desirable to alleviate the energy barriers associated with the cellular uptake of sEVs and minimize the perturbation of sEVs when loading drugs onto them. In this study, we developed a simple drug-loading system for sEVs using a dimeric curvature-sensing peptide, which enhances sEV accumulation on the cell surface by acting as an adhesive, subsequently inducing endocytic uptake of sEVs through a clathrin-mediated pathway. The dimeric curvature-sensing peptide selectively binds to the sEV surface within 10 min, even in the presence of serum proteins, and functions as a membrane interfactant to reduce the energy barriers for the cellular uptake of sEVs. The cellular uptake of sEVs and the dimeric curvature-sensing peptide under coexisting conditions increased to over 5-fold and 20-fold, respectively, compared with those administered alone. Furthermore, the dimeric curvature-sensing peptide can efficiently load anticancer drugs onto the surface of sEVs, and the system effectively induces apoptosis in two types of cancer cells. Dimeric curvature-sensing peptide is a technique with potential applications in drug delivery.