ACS Publications最新文献

Antibacterial nanocarrier-based anticancer drug delivery systems have garnered significant attention in the treatment of bacteria-associated cancers. By employing natural polyphenols in a green synthesis process, the inert surface of conventional silver nanoparticles (AgNPs) can be modified to enable anticancer drug loading and provide dual antibacterial and anticancer functionalities. However, the development of AgNPs with intrinsic antibacterial and antitumor activities for anticancer drug loading and bacteria-associated tumor combination therapy has not been extensively explored. Here, the extract of Rheum tanguticum Maxim. ex Balf. (RHT), an important traditional Chinese medicine, was utilized as a reducing and stabilizing agent for the green synthesis of AgNPs (RHT-AgNPs). The resultant RHT-AgNPs had spherical morphology, good dispersion, uniform particle size (15.14 ± 0.73 nm), and remarkable long-term stability in aqueous solutions (>43 days). Mass spectra (MS) and high-performance liquid chromatography (HPLC) analysis were performed to identify the main constituents in rhubarb extract responsible for the preparation of RHT-AgNPs. The resultant RHT-AgNPs (500 μg/mL) exhibited low long-term (72 h) cytotoxicity against normal cells (cell viability >54%) and retained significant antibacterial activity against both Escherichia coli and Staphylococcus aureus. More importantly, the RHT-AgNPs exhibited significant cytotoxic activity against breast cancer cells (IC₅₀ = 77.92 μg/mL), which originated from the rhubarb extract (IC₅₀ = 20.36 μg/mL), thus enabling an enhanced antitumor effect with the loaded anticancer agent. RHT-AgNPs demonstrated high drug loading efficiency (>86%) for anticancer drug epirubicin (EPI), and the resultant EPI-loaded RHT-AgNPs (RHT-AgNPs/EPI) nanoformulation exhibited unique pH- and glutathione (GSH)-responsive EPI release as well as pH-responsive Ag release behavior. The in vitro cytotoxicity assay indicated that RHT-AgNPs/EPI could significantly improve the effect of bacteria on the cytotoxicity of EPI against breast cancer cells (with an equivalent EPI concentration of 20 μg/mL). Moreover, in an S. aureus infection-associated 4T1 breast tumor-bearing Balb/c mouse model, intravenous administration of RHT-AgNPs/EPI (with an equivalent EPI amount of 5 mg/kg) effectively suppressed infectious inflammation and showed superior tumor suppression compared to the single EPI administration without inducing notable toxic effects on healthy tissues.

Bone regeneration is generally not effective in cases of extensive defects or inflammatory conditions such as osteoporosis and periodontitis. The traditional approach, such as bone grafting, comes with limitations, thereby making tissue engineering strategies a potential alternative. However, successful regeneration needs both osteogenesis and proper immunomodulation. Among all the immune cells, macrophages play a pivotal role in osteoimmunomodulation because of their plasticity in switching between pro-inflammatory (M1) and anti-inflammatory (M2) states. Nanostructured biomaterials can change the polarization of macrophages by altering important immune pathways such as NF-κB, MAPK, PI3K-Akt, JAK-STAT, NLRP3, Notch, and HIF-1 due to their large surface area and adjustable surface chemistry. These nanomaterials have also demonstrated excellent efficacy as carriers for targeted delivery of osteoimmunomodulatory bioactive agents, such as growth factors, cytokines, metal ions, and phytochemicals. In this review, we have discussed the crosstalk between the skeletal system, nanomaterials, and the immune system. We have also discussed the various types of nanomaterials and the design strategy of nanomaterials to modulate immune responses for enhanced bone regeneration. A brief discussion about the molecular pathways involved in osteoimmunomodulation and the modulation of these pathways by nanostructured materials for bone repair is also provided. Finally, we examined how nanomaterials can be engineered as delivery platforms for the controlled release of bioactive molecules involved in immune modulation and bone regeneration.

Multifunctional textiles integrating antimicrobial and thermal-regulatory properties are urgently needed for wound care and personal protection. Here, we developed antibacterial and thermoregulatory Lyocell fibers through covalently grafting aloin and integrating graphene oxide (GO) with phase-change microcapsules (PCMs). The optimal Functional fiber 2 (3% aloin, 4 mg/mL postimmersion aloin, 0.75% GO, and 30% PCMs) exhibited a cylindrical morphology with protrusions and microvoids, and demonstrated 27.61 J/g phase change enthalpy, 16.18 cN tensile strength, and 22.24% breaking elongation. Under standardized shake-flask conditions, Functional fiber 2 completely inhibited Staphylococcus aureus and Escherichia coli growth, and antibacterial efficacy remained at 90.21% and 87.81% after 30 washing cycles. In S. aureus-infected rat wounds, the fiber accelerated healing, reduced the wound diameter by approximately 77% via 14-day treatment, prevented bacterial infection/inflammation, and enhanced angiogenesis. Our fibers are promising for manufacturing protective textiles and medical supplies, also showcasing potential in outdoor protection.

Oral hard-soft tissue repair present significant clinical challenges due to the highly dynamic, moist, microbially colonized, and inflammatory nature of the oral environment. Oral wounds from trauma, surgery, or disease cause discomfort and infection risk, demanding effective protection. The development of wet adhesives capable of robust adhesion to integrate oral hard tissues and soft tissues, while enabling localized therapy, remains a significant challenge. In recent years, hydrogels with tunable surface energy and reversible adhesion have demonstrated exceptional wet adhesion through the synergy of physical, chemical, and dissipative interactions, showing great potential to improve therapeutic effect in oral surgical applications. This review comprehensively examines wet adhesion mechanisms of hydrogels and critically analyzes the physical and chemical foundations of current dental adhesives. By integrating surface modification of hydrogels to the unique requirements of oral soft and hard tissue repair, this work aims to develop next-generation materials that overcome clinical translation barriers.

Degradable polyester materials are widely utilized in medicine as resorbable sutures, implantable devices, and drug delivery. These applications require precise and tunable degradation control; predictable number-average molecular weight (M̅_n), narrow polydispersity (Đ), and diverse material properties define polyester utility, which are not easily achieved through well-established synthesis approaches. Ring-opening copolymerization (ROCOP) provides reproducible M̅_n control, narrow Đ, and expands monomer diversity. In this work, poly(cyclohexene succinate) (PCS) and poly(propylene succinate) (PPS) were synthesized through a central composite design of experiments approach, systematically varying anhydride:epoxide ratio, monomer:catalyst ratio, reaction temperature, and reaction time. Reduced synthesis factor-response models explained the significant variation for all characterized properties relevant to degradation control. PCS and PPS readily degraded under base-catalyzed hydrolysis conditions with significantly higher mass loss in PPS materials compared to PCS, highlighting the monomer selection influence in degradation behavior. These findings highlight the potential for ROCOP to generate degradable biomaterials with reproducible material properties for application-specific biomedical use.

This study presents the development of titanium-based implants coated with zeolite layers for controlled delivery of epigallocatechin gallate (EGCG), a polyphenolic compound with osteogenic, antiresorptive, and antibacterial properties. Zeolite coatings were modified with divalent ions (Zn²⁺, Mg²⁺, Ca²⁺) to investigate their influence on EGCG adsorption and release under neutral (pH 7.4, SBF) and acidic (pH 5.0, acetate buffer) conditions. Comprehensive characterization using SEM, EDS, FT-IR, UV-vis spectroscopy, and surface profilometry confirmed uniform zeolite formation, effective EGCG loading, and tunable release profiles. Zinc-containing zeolite exhibited the highest EGCG adsorption but demonstrated cytotoxicity toward hFOB 1.19 osteoblasts. Magnesium-zeolite-coated implants provided controlled EGCG release, were nontoxic, and did not support cell adhesion, making them suitable for temporary internal fixation in the management of orthopedic trauma. Release studies revealed pH-dependent kinetics, with accelerated EGCG release under acidic conditions simulating osteoclast activity. These findings demonstrate the potential of Mg-zeolite-coated titanium implants as functional devices that provide mechanical support, enable localized drug delivery, and promote bone regeneration while minimizing tissue damage during removal.

Elastin-like polypeptides (ELPs) are self-assembling recombinant biopolymers that can be precisely engineered to display functional targeting ligands. In this study, we developed ELP-based nanoparticles (NPs) displaying the variable domain of the heavy chain of heavy-chain-only antibodies (VHHs) targeting the SARS-CoV-2 spike protein. By tuning VHH selection, multivalency, and surface display density, we created targeted ELP NPs capable of blocking entry of spike-protein-presenting virus-like particles (VLPs) and live viruses, with subnanomolar IC₅₀ values, significantly outperforming the monovalent VHH equivalents. Notably, optimizing multivalency and VHH density unlocked broad virus-neutralizing potency against multiple variants, including Omicron variants resistant against the monovalent VHH equivalents. Confocal imaging further revealed that VHH-ELP NPs formed aggregates with VLPs, enhancing uptake by M1 macrophages, suggesting potential for eliciting vaccinal effects. Overall, this work highlights the versatility of ELP NPs as a tunable antiviral platform and provides design principles for next-generation nanotherapeutics against evolving viral threats.

Mechanoresponsive biomaterials are a revolutionary class of materials designed to respond dynamically to mechanical stimuli, providing tissue engineering and regenerative medicine with precise control over biological processes. Through processes including supramolecular interactions, strain stiffening, and force-induced conformational changes, these materials, which include hydrogels, elastomers, and piezoelectric composites, imitate the mechanics exclusive to biological tissues. Additionally, mechanoresponsive systems improve drug delivery by releasing drugs in response to pH changes or mechanical strain using various materials, including magnetic scaffolds and ultrasound-triggered micelles. Despite advancements in numerous arenas of biological sciences, problems with clinical translation, scalability, and long-term biocompatibility still exist. New developments combine technologies like 4D bioprinting to create dynamic, patient-specific scaffolds and artificial intelligence (AI)-assisted design to maximize material qualities. To achieve material innovation with the desired level of biological complexity, future initiatives should focus on multifunctional platforms that combine mechanical, electrical, and biochemical inputs at an advanced level. This review dives into several aspects of mechanoresponsive biomaterials by navigating through the fabrication methods, underlying principles, inception of these in biomedical applications, and progression through the current research settings.

A novel core-shell hybrid material composed of bioactive glass (BG) nanoparticles and the metal-organic framework (MOF) MIL-100(Fe) (Fe₃O(H₂O)₂OH(BTC)₂·nH₂O, BTC: 1,3,5-benzenetricarboxylate) was synthesized using a layer-by-layer strategy. The formation of the MIL-100(Fe) shell on the BG core was directly confirmed by high-resolution transmission electron microscopy, which revealed a continuous MOF layer with an average thickness of 6.1 ± 0.9 nm. Complementary characterization by infrared spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, N₂ sorption, and synchrotron-based X-ray absorption spectroscopy (XAS) confirmed the coexistence of MIL-100(Fe) and BG components and their structural integrity within the hybrid material. Notably, for the first time, a synchrotron-based technique (XAS) was used to characterize the MOF@BG system, providing unique insight into its local coordination environment and structural evolution. The hybrid material demonstrated favorable cytocompatibility in a long-term (21-day) assay on mouse osteoblast precursor cells (MC3T3) and human dermal fibroblasts (HDF). At the same time, it did not induce ex vivo hemolysis at concentrations up to 1000 μg/mL. The induction of osteogenic differentiation in MC3T3 cells in the presence of MIL-100(Fe)@BG was confirmed by early osteogenic markers, including alkaline phosphatase (ALP) activity and alizarin red staining (ARS). Bioactivity studies in Dulbecco's phosphate-buffered saline (DPBS) and simulated body fluid (SBF) revealed rapid formation of nanohydroxyapatite, beginning within the first hours of incubation. Importantly, under physiological conditions, the MIL-100(Fe) shell undergoes a controlled structural transformation, yielding highly dispersed nanoscale Fe₂O₃ particles. These nanoparticles induce the production of reactive oxygen species (ROS) and contribute to antibacterial activity, thereby inhibiting E. coli and S. aureus without the need for external antimicrobial agents. The combination of bioactivity, osteogenic potential, hemocompatibility, and intrinsic antibacterial functionality positions MIL-100(Fe)@BG as a promising multifunctional platform for bone regeneration and infection control.

Cellulose nanofiber (CNF) has been reported to enhance the mechanical and crystallization properties of poly(lactic acid) (PLA); nevertheless, its role in PLA chemical recycling via pyrolysis remains unexplored. This study revealed that PLA incorporated with 3 wt % CNF (PLA/CNF3) exhibited a marked reduction in its thermal depolymerization activation energy to 152 kJ/mol, compared to 169 kJ/mol of neat PLA, indicating that CNF facilitated thermal depolymerization of PLA. Further investigation by pyrolysis-GC/MS showed that pyrolyzates of PLA/CNF3 contained mainly lactide (≈90%) in contrast to only 69% lactide in that of neat PLA, confirming that the addition of CNF catalyzed the thermal depolymerization of PLA into lactide. The water molecule released from the CNF accelerates PLA hydrolysis, forming -COOH-terminated oligomers in situ, which then intensify the autocatalytic degradation. This finding highlights another important role of CNF in PLA as a green catalyst for thermal depolymerization, advancing PLA chemical recycling for plastic circularity.