Suitable Isolation Side Chains: A Simple Strategy for Simultaneously Improving the Phototherapy Efficacy and Biodegradation Capacities of Conjugated Polymer Nanoparticles.

Utilizing one molecule to realize combinational photodynamic and photothermal therapy upon single-wavelength laser excitation, which relies on a multifunctional phototherapy agent, is one of the most cutting-edge research directions in tumor therapy owing to the high efficacy achieved over a short course of treatment. Herein, a simple strategy of "suitable isolation side chains" is proposed to collectively improve the fluorescence intensity, reactive oxygen species production, photothermal conversion efficiency, and biodegradation capacity. Both in vitro and in vivo results reveal the practical value and huge potential of the designed biodegradable conjugated polymer PTD-C16 with suitable isolation side chains in fluorescence image-guided combinational photodynamic and photothermal therapy. These improvements are achieved through manipulation of aggregated states by only side chain modification without changing any conjugated structure, providing new insight into the design of biodegradable high-performance phototherapy agents.

Type-I Photosensitizer-Triggered Controllable Carbon Monoxide Release for Effective Treatment of Staph Skin Infection.

Staphylococcus aureus (S. aureus) infection is a major infectious skin disease that is highly resistant to conventional antibiotic treatment and host immune defense, leading to recurrence and exacerbation of bacterial infection. Herein, we developed a photoresponsive carbon monoxide (CO)-releasing nanocomposite by integrating anion-π+ type-I photosensitizer (OMeTBP) and organometallic complex (FeCO) for the treatment of planktonic S. aureus and biofilm-associated infections. After optimizing the molar ratio of FeCO and OMeTBP, the prepared nanoparticles, OMeTBP@FeCONPs, not only ensured sufficient loading of CO donors and efficient CO generation but also showed negligible free ROS leakage under light irradiation, which helped to avoid tissue damage caused by excessive ROS. Both in vitro and in vivo results demonstrated that OMeTBP@FeCONPs could effectively inhibit S. aureus methicillin-resistant S. aureus (MRSA), and bacterial biofilm. Our design has the potential to overcome the resistance of conventional antibiotic treatment and provide a more effective option for bacterial infections.

Near-infrared chemiluminescent nanoprobes for deep imaging and synergistic photothermal-nitric-oxide therapy of bacterial infection.

Bacterial infection is the leading cause of many serious inflammation diseases threatening human health. Existing theranostic options for bacterial infection are always complicated and unsatisfactory. There is an increasing interest in developing a more effective theranostic approach for the treatment of infections. Herein, we report the development of a near-infrared (NIR) chemiluminescent (CL) nanoparticles ALPBs containing luminol, AIE dye (TTDC), PCPDTBT, and nitric oxide (NO) donor (BNN6), which could achieve a deep CL imaging-guided photothermal-NO gas therapy of bacterial infection. After intravenous injection, ALPBs could be largely accumulated in the infected site and then activated by oversecreted reactive oxygen species (ROS) to produce near-infrared chemiluminescence, which could precisely track infection-induced local inflammation. Under the guidance of imaging, synergistic photothermal-NO therapy was further performed by 808 nm laser irradiation, leading to active bacterial eradication and rapid recovery of infected tissues. The utility of ALPBs provides a powerful and controllable "all-in-one" platform for combating bacterial infection.