RESUMEN
The presence of multidrug-resistant bacteria has challenged the clinical treatment of bacterial infection. There is a real need for the development of novel biocompatible materials with broad-spectrum antimicrobial activities. Antimicrobial hydrogels show great potential in infected wound healing but are still being challenged. Herein, broad-spectrum antibacterial and mechanically tunable amyloid-based hydrogels based on self-assembly and local mineralization of silver nanoparticles are reported. The mineralized hydrogels are biocompatible and have the advantages of sustained release of silver, prolonged antimicrobial effect, and improved adhesion capacity. Moreover, the mineralized hydrogels display a significant antimicrobial effect against both Gram-positive and Gram-negative bacteria in cells and mice by inducing membrane damage and reactive oxygen species toxicity in bacteria. In addition, the mineralized hydrogels can rapidly accelerate wound healing by the synergy between their antibacterial activity and intrinsic improvement for cell proliferation and migration. This study provides a modular approach to developing a multifunctional protein hydrogel platform based on biomolecule-coordinated self-assembly for a wide range of biomedical applications.
Asunto(s)
Antibacterianos , Proliferación Celular , Hidrogeles , Plata , Cicatrización de Heridas , Plata/química , Plata/farmacología , Animales , Hidrogeles/química , Hidrogeles/farmacología , Cicatrización de Heridas/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ratones , Antibacterianos/química , Antibacterianos/farmacología , Nanopartículas del Metal/química , Humanos , Especies Reactivas de Oxígeno/metabolismo , Pruebas de Sensibilidad Microbiana , Antiinfecciosos/farmacología , Antiinfecciosos/química , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacologíaRESUMEN
A single-atom metal doped on carbonaceous nanomaterials has attracted increasing attention due to its potential applications as high-performance catalysts. However, few studies focus on the applications of such nanomaterials as nanotheranostics for simultaneous bioimaging and cancer therapy. Herein, it is pioneeringly demonstrated that the single-atom Gd anchored onto graphene quantum dots (SAGd-GQDs), with dendrite-like morphology, was successfully prepared. More importantly, the as-fabricated SAGd-GQDs exhibits a robustly enhanced longitudinal relaxivity (r1 = 86.08 mM-1 s-1) at a low Gd3+ concentration of 2 µmol kg-1, which is 25 times higher than the commercial Gd-DTPA (r1 = 3.44 mM-1 s-1). In vitro and in vivo studies suggest that the obtained SAGd-GQDs is a highly potent and contrast agent to obtain high-definition MRI, thereby opening up more opportunities for future precise clinical theranostics.