Short-Wavelength Aggregation-Induced Emission Photosensitizers for Solid Tumor Therapy: Enhanced with White-Light Fiber Optic

Abstract

Background White-light photodynamic therapy (wPDT) has been used in the treatment of cancer due to its convenience, effectiveness and less painful. However, the limited penetration of white-light into the tissues leads to a reduced effectiveness of solid tumor treatment. Methods Two short-wavelength aggregation-induced emission (AIE) nanoparticles were prepared, PyTPA@PEG and TB@PEG, which have excitation wavelengths of 440 nm and 524 nm, respectively. They were characterized by UV, fluorescence, particle size and TEM. The ability of nanoparticles to produce reactive oxygen species (ROS) and kill cancer cells under different conditions was investigated in vitro, including white-light, after white-light penetrating the skin, laser. A white-light fiber for intra-tumor irradiation was customized. Finally, induced tumor elimination with fiber-mediated wPDT was confirmed in vivo. Results In vitro, both PyTPA@PEG and TB@PEG are more efficient in the production ROS when exposed to white-light compared to laser. However, wPDT also has a fatal flaw in that its level of ROS production after penetrating the skin is reduced to 20–40% of the original level. To this end, we have customized a white-light fiber for intra-tumor irradiation. In vivo, the fiber-mediated wPDT significantly induces tumor elimination with maximized therapeutic outcomes by irradiating the interior of the tumor. In addition, wPDT also has the advantage that its light source can be adapted to a wide range of photosensitizers (wavelength range 400–700 nm), whereas a laser of single wavelength can only target a specific photosensitizer. Conclusion This method of using optical fiber to increase the tissue penetration of white light can greatly improve the therapeutic effect of AIE photosensitizers, which is needed for the treatment of large/deep tumors and holds great promise in cancer treatment.

Macrophage Membrane‐Camouflaged Aggregation‐Induced Emission Nanoparticles Enhance Photodynamic‐Immunotherapy to Delay Postoperative Tumor Recurrence

“…PI staining is commonly used to indicate late apoptosis or cell death; while, CMFDA staining is used to indicate survival or live cells. [22] As expected, the co-staining results showed that the tumor cells were killed when both M@PFC and light conditions were present together, as shown in Figure 2D. This indicates that M@PFC has the capacity to induce cell death in 4T1 cells under light conditions.…”

Fiber-Optic Biosensors for Cancer Theranostics: From in Vitro to in Vivo

“…16(a), white light photodynamic therapy (wPDT) has been used in the treatment of cancer because of its convenience, effectiveness, and low pain. Two short-wavelength aggregationinduced luminescence (AIE) nanoparticles (PyTPA@PEG and TB@PEG) were prepared for the further killing of cancer cells by reactive oxygen species [144]. The fiber-mediated PDT enhances tissue penetration, which significantly induces tumor elimination and maximizes the therapeutic effect by irradiating inside the tumor.…”

Hydrogel systems for targeted cancer therapy

“…Photodynamic therapy mainly depends on light-harvesting photosensitizers to ingest light of specific wavelengths and then produce reactive oxygen species (ROS), consequently causing oxidative harm to cancer cells ( Zhang et al, 2022b ). However, most photosensitizers need to be activated by short-wavelength light from the ultraviolet (UV) to visible light regions and have low tissue penetration, leading to unacceptable and inadequate therapeutic impacts.However, photodynamic therapy based on X-ray and near-infrared light requires long-term exposure to outside light, which might lead to unanticipated tissue damage because of radiation damage and thermal effects, respectively ( Meng et al, 2022c ). Recently, Shu et al (2021) successfully developed a rechargeable photodynamic immune hydrogel capable of persistent luminescence by introducing a persistent luminescent material and an immune adjuvant (R837) into alginate-like substances.…”