Polymer–inorganic hybrid Janus nanoparticles (PI‐JNPs) have attracted extensive attention due to their special structures and functions. However, achieving the synergistic enhancement of photochemical activity between polymer and inorganic moieties in PI‐JNPs remains challenging. Herein, the construction of a novel Janus Au–porphyrin polymersome (J‐AuPPS) heterostructure by a facile one‐step photocatalytic synthesis is reported. The near‐field enhancement (NFE) effect between porphyrin polymersome (PPS) and Au nanoparticles in J‐AuPPS is achieved to enhance its near‐infrared (NIR) light absorption and electric/thermal field intensity at their interface, which improves the energy transfer and energetic charge‐carrier generation. Therefore, J‐AuPPS shows a higher NIR‐activated photothermal conversion efficiency (48.4%) and generates more singlet oxygen compared with non‐Janus core–particle Au–PPS nanostructure (28.4%). As a result, J‐AuPPS exhibits excellent dual‐mode (photothermal/photodynamic) antibacterial and anti‐biofilm performance, thereby significantly enhancing the in vivo therapeutic effect in an implant‐associated‐infection rat model. This work is believed to motivate the rational design of advanced hybrid JNPs with desirable NFE effect and further extend their biological applications.

As a non-invasive and non-specific therapeutic approach, photodynamic therapy (PDT) has been used to treat antibiotic-resistant bacteria with encouraging efficacy. Inspired by light, the photosensitizers can produce excessive reactive oxygen species (ROS) and, thus, effectively destroy or kill bacteria. Cyanine (Cy), a traditional photosensitizer for PDT, has the advantages of low cytotoxicity and high ROS yield. Yet, the water solubility and photostability for Cy are poor, which substantially limit its antibacterial efficiency and clinical translation. Herein, we combined Cy with carbomer gel (CBMG) to form a photodynamic Cy-CBMG hydrogel. In this system, Cy was evenly dispersed in CBMG, and CBMG significantly improved the water solubility and photostability of Cy via electrostatic interactions. The developed Cy-CBMG gel had less photodegradation under laser irradiation and thus can effectively elevate ROS accumulation in bacteria. The Cy-CBMG compound presented remarkable ROS-induced killing efficacy against methicillin-resistant Staphylococcus aureus (93.0%) and extended-spectrum β-lactamase-producing Escherichia coli (88.7%) in vitro. Moreover, as a potential wound dressing material, the Cy-CBMG hydrogel exhibited excellent biocompatibility and effective antimicrobial ability to promote wound healing in vivo. Overall, this work proposed a practical strategy to synthesize a photosensitizer–excipient compound to enhance the photophysical property and antibacterial efficacy for PDT.

Materials in nature feature versatile and programmable interactions to render macroscopic architectures with multiscale structural arrangements. By rationally combining metal–carboxylate and metal–organophosphate coordination interactions, Au25(MHA)18 (MHA, 6-mercaptohexanoic acid) nanocluster self-assembled structural color coating films and phytic acid (PA)–metal coordination complexes are sequentially constructed on the surface of titanium implants. The Lewis acid–base coordination principle applies for these metal–organic coordination networks. The isotropic arrangement of nanoclusters with a short-range order is investigated via grazing incidence wide-angle X-ray scattering. The integration of robust M–O (M = Ti, Zr, Hf) and labile Cu–O coordination bonds with high connectivity of Au25(MHA)18 nanoclusters enables these artificial photonic structures to achieve a combination of mechanical stability and bacteriostatic activity. Moreover, the colorless and transparent PA–metal complex layer allows the viewing of the structural color and surface wettability switching to hydrophilic and makes feasible the interfacial biomineralization of hydroxyapatite. Collectively, these modular metal–organic coordination-driven assemblies are predictive and rational material design strategies with tunable hierarchy and diversity. The complete metal–organic architectures will not only help improve the physicochemical properties of the bone–implant interface with synergistic antibacterial and osseointegration activities but also can boost surface engineering of medical metal implants