A copper-metal organic framework enhances the photothermal and chemodynamic properties of polydopamine for melanoma therapy.

The combination of photothermal treatment and chemodynamic therapy has attracted extensive attention for improving therapeutic effects and compensating the insufficiency of monotherapy. In this work, a copper-metal organic framework (Cu-BTC) was used to augment the photothermal effect of polydopamine (PDA) and endow it with a chemodynamic ability by constructing a Cu-BTC@PDA nanocomposite. Density functional theory calculations revealed that the plasmonic vibrations formed by the d-d transition of Cu at the Fermi level in Cu-BTC@PDA could enhance the photothermal performance of PDA. In addition, more Cu2+ released from Cu-BTC@PDA in the acidic microenvironment of the tumor was then reduced to Cu+ by glutathione (GSH) and further catalyzed H2O2 to generate more toxic hydroxyl radical (•OH), which synergized with photothermal treatment for melanoma therapy. Furthermore, Cu-BTC@PDA could quickly and effectively kill bacteria under the action of PTT, and the sustained release of Cu ions could contribute to the long-term and stable bacteriostatic ability of the material. This sustained release of Cu ions could also promote the cell migration and angiogenesis, and upregulate the expression of COL-, TGF-, and VEGF-related genes to accelerate wound healing. This multifunctional nanomaterial has potential application in the treatment of melanoma and repair of wounds. STATEMENT OF SIGNIFICANCE: We constructed a multifunctional nanoplatform (Cu-BTC@PDA) by two steps. This nanoplatform can not only perform cascade catalysis in the tumor microenvironment to generate more toxic hydroxyl radical (•OH), but also synergize with photothermal treatment for melanoma therapy. Additionally, Cu-BTC@PDA possesses enhanced photothermal performance through the plasmonic vibrations formed by the d-d transition of Cu at the Fermi level in Cu-BTC@PDA, which is revealed by DFT calculations. And Cu-BTC@PDA shows good antitumor, antibacterial, and wound healing properties in vivo and in vitro. Such a multifunctional nanomaterial has potential application in the treatment of melanoma and repair of wounds.

On-Off Phagocytosis and Switchable Macrophage Activation Stimulated with NIR for Infected Percutaneous Tissue Repair of Polypyrrole-Coated Sulfonated PEEK.

Intelligent control of the immune response is essential for obtaining percutaneous implants with good sterilization and tissue repair abilities. In this study, polypyrrole (Ppy) nanoparticles enveloping a 3D frame of sulfonated polyether ether ketone (SP) surface are constructed, which enhance the surface modulus and hardness of the sulfonated layer by forming a cooperative structure of simulated reinforced concrete and exhibit a superior photothermal effect. Ppy-coated SP could quickly accumulate heat on the surface by responding to 808 nm near-infrared (NIR) light, thereby killing bacteria, and destroying biofilms. Under NIR stimulation, the phagocytosis and M1 activation of macrophages cultured on Ppy-coated SP are enhanced by activating complement 3 and its receptor, CD11b. Phagocytosis and M1 activation are impaired along with abolishment of NIR stimulation in the Ppy-coated SP group, which is favorable for tissue repair. Ppy-coated SP promotes Collagen-I, vascular endothelial growth factor, connective tissue growth factor, and α-actin (Acta2) expression by inducing M2 polarization owing to its higher surface modulus. Overall, Ppy-coated SP with enhanced mechanical properties could be a good candidate for clinical percutaneous implants through on-off phagocytosis and switchable macrophage activation stimulated with NIR.

Constructing fluorine-doped Zr-MOF films on titanium for antibacteria, anti-inflammation, and osteogenesis.

Implant infection, undesirable inflammation, and poor osseointegration are the primary reasons for implant failure, so it is pivotal to endow bone implants with antibacterial, anti-inflammatory, and osteogenic properties. Here, a multifunctional fluorine-doped zirconium-metal organic framework (Zr-MOF) film was constructed on the titanium to modify its biological performances. The fumaric acid, a common antioxidant, was selected as the ligand of Zr-MOF, and the hydrofluoric acid was used as the modulator to control the growth of Zr-MOF film. The obtained fluorine-doped Zr-MOF film possessed good biocompatibility and osteogenic ability, and it showed good antibacterial effects against both gram-positive S. aureus and gram-negative E. coli due to the release of fluoride ions. In addition, the doping of fluorine could reduce the stability of Zr-MOF by substituting fumaric acid, and stimulating the releases of fumaric acid. Furthermore, the fumaric acid released from Zr-MOF could down-regulate the expression of pro-inflammatory genes (NF-κB and IL-6), but up-regulate the expression of anti-inflammatory gene of IL-4 of macrophage, showing good anti-inflammatory ability. This study provided a reference for the modulation synthesis of MOF film, and proposed a promising strategy of designing Zr-MOF film to endow bone implants with antibacterial, anti-inflammatory, and osteogenic abilities.

Regulation of Ce (â ¢) / Ce (â £) ratio of cerium oxide for antibacterial application.

Antibiotics have been considered as effective weapons against bacterial infections since they were discovered. However, antibiotic resistance caused by overuse and abuse of antibiotics is an emerging public health threat nowadays. Fully defeating bacterial infections has become a tough challenge. In this work, cerium oxide was fabricated on medical titanium by thermolysis of cerium-containing metal-organic framework (Ce-BTC). Regulation of Ce (Ⅲ)/Ce (Ⅳ) ratios was realized by pyrolysis of Ce-BTC in different gas environment, and the antibacterial properties were studied. The results indicated that, in acidic conditions, ceria with a high Ce (Ⅲ)/Ce (Ⅳ) ratio owned high oxidase-like activity which could produce reactive oxygen species. Moreover, ceria with high Ce (Ⅲ) content possessed strong ATP deprivation capacity which could cut off the energy supply of bacteria. Based on this, ceria with a high Ce (Ⅲ)/Ce (Ⅳ) ratio exhibited superior antibacterial activity.

PEO/Mg-Zn-Al LDH Composite Coating on Mg Alloy as a Zn/Mg Ion-Release Platform with Multifunctions: Enhanced Corrosion Resistance, Osteogenic, and Antibacterial Activities.

The design of advanced multifunctional Mg-based bone implants with enhanced corrosion resistance, antibacterial, and osteogenic activities should be brought to the forefront to fulfill the requirement of clinical medicine. In this work, a PEO/Mg-Zn-Al layered double hydroxide (LDH) composite coating on Mg alloy was developed via plasma electrolytic oxidation (PEO) and hydrothermal treatment. The porous structure formed during the PEO process was filled by Mg-Zn-Al LDH. The as-prepared coating exhibited better corrosion resistance than the PEO/Mg-Al LDH composite coating. In addition, the composite coating showed strong antimicrobial ability against Gram-positive Staphylococcus aureus, which was attributed to the release of Zn ions. When Zn content was controlled at 1.17 at% in the composite coating, rBMSCs showed long-term cytocompatibility and enhanced initial adhesion. Moreover, with the synergistic functions of Zn and Mg ions, cells on the composite coating showed a higher level of alkaline phosphatase activity and expression of osteopontin (OPN). With enhanced corrosion resistance, antibacterial, and osteogenic differentiation abilities, the PEO/Mg-Zn-Al LDH composite coating exhibits a promising application in bone-related implants.