Aggregation-induced emission biomaterials for anti-pathogen medical applications: detecting, imaging and killing

Aggregation-Induced Emission Luminogen Based Wearable Visible-Light Penetrator for Deep Photodynamic Therapy

Photodynamic therapy (PDT) has emerged as a preferred nonsurgical treatment in clinical applications due to its capacity to selectively eradicate diseased tissues while minimizing damage to normal tissue. Nevertheless, its clinical efficacy is constrained by the limited penetration of visible light. Although near-infrared (NIR) lasers offer enhanced tissue penetration, the dearth of suitable photosensitizers and a pronounced imaging-treatment disparity pose challenges. Additionally, clinical implementation via optical fiber implantation carries infection risks and necessitates minimally invasive surgery, contradicting PDT's noninvasive advantage. In this study, we introduce a brilliant approach utilizing aggregation-induced emission luminogens (AIEgen) to develop a visible-light penetrator (VLP), coupled with wireless light emitting diodes (LEDs), enabling deep photodynamic therapy. We validate the therapeutic efficacy of this visible-light penetrator in tissues inaccessible to conventional PDT, demonstrating significant suppression of inflammatory diffusion in vivo using AIEgen TBPPM loaded within the VLP, which exhibits a transmittance of 86% in tissues with a thickness of 3 mm. This innovative visible-light penetrator effectively overcomes the substantial limitations of PDT in clinical settings and holds promise for advancing phototherapy.

Aggregation-Induced Emission Luminogen: Role in Biopsy for Precision Medicine

Biopsy, including tissue and liquid biopsy, offers comprehensive and real-time physiological and pathological information for disease detection, diagnosis, and monitoring. Fluorescent probes are frequently selected to obtain adequate information on pathological processes in a rapid and minimally invasive manner based on their advantages for biopsy. However, conventional fluorescent probes have been found to show aggregation-caused quenching (ACQ) properties, impeding greater progresses in this area. Since the discovery of aggregation-induced emission luminogen (AIEgen) have promoted rapid advancements in molecular bionanomaterials owing to their unique properties, including high quantum yield (QY) and signal-to-noise ratio (SNR), etc. This review seeks to present the latest advances in AIEgen-based biofluorescent probes for biopsy in real or artificial samples, and also the key properties of these AIE probes. This review is divided into: (i) tissue biopsy based on smart AIEgens, (ii) blood sample biopsy based on smart AIEgens, (iii) urine sample biopsy based on smart AIEgens, (iv) saliva sample biopsy based on smart AIEgens, (v) biopsy of other liquid samples based on smart AIEgens, and (vi) perspectives and conclusion. This review could provide additional guidance to motivate interest and bolster more innovative ideas for further exploring the applications of various smart AIEgens in precision medicine.

Aggregation-induced emission photosensitizer for antibacterial therapy of methicillin-resistant Staphylococcus aureus

A cationic aggregation-induced emission photosensitizer (AIE-PS) MNNPyBB has been reported to have antibacterial effects against both Gram-positive and Gram-negative bacteria. The bacterial kill mechanism has been investigated and elucidated. In a methicillin-resistant Staphylococcus aureus subcutaneous infection model, wound closure has been achieved with normal re-epithelialization and preserved skin morphology.

Fast and Stable Antibacterial Coating of Photosensitive Aggregation-Induced Emission Luminogens for Disinfection on Medical Devices

Aggregation-induced emission luminogens (AIEgens) are promising photosensitizers that have exhibited excellent antibacterial ability with abundant reactive oxygen species (ROS) generation. TTCPy-PF6 and TTCPy-Br are deposited on the surface of diverse solid substrates through plasma-assistant electrostatic self-assembly. The AIEgens-covered coating can effectively eliminate different pathogenic Gram-positive (G+) bacteria and even their multidrug-resistant (MDR) mutants with negligible side effects such as cytotoxicity, hemolysis, and inflammation. Moreover, the AIEgen-coated surface can maintain high stability for long-time antibacterial usage, which is dependent on the ROS-mediated disruption of the attached bacteria. The AIEgen-based coatings with broad surface applicability have many advantages in high antibacterial ability, great biocompatibility, and low possibility of antibiotic pollution. The robust antibacterial ability and excellent biological safety of the AIEgen-based coatings would be helpful for the disinfection of medical devices.

Cuprorivaite/hardystonite/alginate composite hydrogel with thermionic effect for the treatment of peri-implant lesion

Peri-implant lesion is a grave condition afflicting numerous indi-viduals with dental implants. It results from persistent periodontal bacteria accumulation causing inflammation around the implant site, which can primarily lead to implant loosening and ultimately the implant loss. Early-stage peri-implant lesions exhibit symptoms akin to gum disease, including swelling, redness and bleeding of the gums surrounding the implant. These signs indicate infection and inflammation of the peri-implant tissues, which may result in bone loss and implant failure. To address this problem, a thermionic strategy was applied by designing a cuprorivaite-hardystonite bioceramic/alginate composite hydrogel with photothermal and Cu/Zn/Si multiple ions releasing property. This innovative approach creates a thermionic effect by the release of bioactive ions (Cu2+ and Zn2+ and SiO 3 2 - ) from the composite hydrogel and the mild heat environment though the photothermal effect of the composite hydrogel induced by near-infrared light irradiation. The most distinctive advantage of this thermionic effect is to substantially eliminate periodontal pathogenic bacteria and inhibit inflammation, while simultaneously enhance peri-implant osseointegration. This unique attribute renders the use of this composite hydrogel highly effective in significantly improving the survival rate of implants after intervention in peri-implant lesions, which is a clinical challenge in periodontics. This study reveals application potential of a new biomaterial-based approach for peri-implant lesion, as it not only eliminates the infection and inflammation, but also enhances the osteointegration of the dental implant, which provides theoretical insights and practical guidance to prevent and manage early-stage peri-implant lesion using bioactive functional materials.

Advancements in Biosensors Based on the Assembles of Small Organic Molecules and Peptides

Over the past few decades, molecular self-assembly has witnessed tremendous progress in a variety of biosensing and biomedical applications. In particular, self-assembled nanostructures of small organic molecules and peptides with intriguing characteristics (e.g., structure tailoring, facile processability, and excellent biocompatibility) have shown outstanding potential in the development of various biosensors. In this review, we introduced the unique properties of self-assembled nanostructures with small organic molecules and peptides for biosensing applications. We first discussed the applications of such nanostructures in electrochemical biosensors as electrode supports for enzymes and cells and as signal labels with a large number of electroactive units for signal amplification. Secondly, the utilization of fluorescent nanomaterials by self-assembled dyes or peptides was introduced. Thereinto, typical examples based on target-responsive aggregation-induced emission and decomposition-induced fluorescent enhancement were discussed. Finally, the applications of self-assembled nanomaterials in the colorimetric assays were summarized. We also briefly addressed the challenges and future prospects of biosensors based on self-assembled nanostructures.