Feedback-Elevated Antitumor Amplifier of Self-Delivery Nanomedicine by Suppressing Photodynamic Therapy-Caused Inflammation

Emerging COX-2 inhibitors-based nanotherapeutics for cancer diagnosis and treatment

Increasing evidence has showed that tumorigenesis is closely linked to inflammation, regulated by multiple signaling pathways. Among these, the cyclooxygenase-2/prostaglandin E2 (COX-2/PGE2) axis plays a crucial role in the progression of both inflammation and cancer. Inhibiting the activity of COX-2 can reduce PGE2 secretion, thereby suppressing tumor growth. Therefore, COX-2 inhibitors are considered potential therapeutic agents for cancers. However, their clinical applications are greatly hindered by poor physicochemical properties and serious adverse effects. Fortunately, the advent of nanotechnology offers solutions to these limitations, enhancing drug delivery efficiency and mitigating adverse effects. Given the considerable progress in this area, it is timely to review emerging COX-2 inhibitors-based nanotherapeutics for cancer diagnosis and therapy. In this review, we first outline the various antineoplastic mechanisms of COX-2 inhibitors, then comprehensively summarize COX-2 inhibitors-based nanotherapeutics for cancer monotherapy, combination therapy, and diagnosis. Finally, we highlight and discuss future perspectives and challenges in the development of COX-2 inhibitors-based nanomedicine.

CsxWO3@NBs as a Multi-Image Guided Photothermal/Photodynamic Combination Therapy Platform for the Treatment of Hepatocellular Carcinoma

Purpose

Effective cancer treatment relies on the precise deployment of clinical imaging techniques to accurately treat tumors. One highly representative technology among these is multi-imaging guided phototherapy. This work introduces a new and innovative theranostic drug that combines near-infrared (NIR) irradiation-induced photodynamic therapy (PDT) and photothermal therapy (PTT) to treat malignancies. Moreover, it can be utilized as a contrasting substance for X-ray computed tomography (CT) imaging and contrast-enhanced ultrasound (CEUS) to aid in the administration of therapy.

Methods

Cesium tungsten bronze nanobubbles (CsxWO3@NBs) were constructed via a water-controlled solvothermal synthesis and thin film hydration of phospholipid. Various methods, including dynamic light scattering, transmission electron microscopy, and X-ray photoelectron spectroscopy, were used to analyze and describe the size, shape, and chemical characteristics of the nanoparticles. In this study, hepatoma cell lines HepG2 and HUH7 were employed in vitro, and xenotransplantation mouse models were used to assess their antitumor effects. A series of in vitro and in vivo trials were conducted to assess the effectiveness of combining photodynamic and photothermal therapies, as well as using CEUS and CT imaging.

Results

The CsxWO3@NBs exhibit photothermal effects and the generation of reactive oxygen species (ROS) under laser irradiation, thereby enabling effective photothermal and photodynamic combinatorial therapy. Following combined treatment, the activity and invasive capacity of hepatocellular carcinoma cells were markedly diminished, the development rate of the tumor was noticeably reduced, and the level of biological toxicity was low. Additionally, CsxWO3@NBs possess the capacity to serve as both a CT imaging agent and a contrast-enhanced ultrasound agent.

Conclusion

CsxWO3@NBs represent a promising theranostic agent for image-guided cancer therapy.

A Self-Delivery Nanodrug Simultaneously Inhibits COX-2/PGE2 Mediated Inflammation and Downregulates PD-L1 to Boost Photoimmunotherapy

Phototherapy promotes anti-tumor immunity by inducing immunogenic cell death (ICD), However, the accompanying inflammatory responses also trigger immunosuppression, attenuating the efficacy of photo-immunotherapy. Herein, they co-assembled a cell-membrane targeting chimeric peptide C16-Cypate-RRKK-PEG8-COOH (CCP) and anti-inflammatory diclofenac (DA) to develop a nanodrug (CCP@DA) that both enhances the immune effect of phototherapy and weakens the inflammation-mediated immunosuppression. CCP@DA achieves cell membrane-targeting photodynamic and photothermal synergistic therapies to damage programmed death ligand 1 (PD-L1) and induce a strong ICD to activate anti-tumor response. Simultaneously, the released DA inhibits the cycoperoxidase-2 (COX-2)/prostaglandin E2 (PGE2) pathway in tumor cells to inhibit pro-tumor inflammation and further down-regulate PD-L1 expression to relieve the immunosuppressive microenvironment. CCP@DA significantly inhibited tumor growth and inflammation both in vitro and in vivo, while maintaining a potent anti-tumor immune response. Additionally, it exhibits excellent anti-metastatic capabilities and prolongs mouse survival time with a single dose and low levels of near-infrared (NIR) light exposure. This work provides a valuable strategy to control the therapy-induced inflammation for high-efficiency photoimmunotherapy.

Single-Component Dual-Functional Autoboost Strategy by Dual Photodynamic and Cyclooxygenase-2 Inhibition for Lung Cancer and Spinal Metastasis

Coloading adjuvant drugs or biomacromolecules with photosensitizers into nanoparticles to enhance the efficiency of photodynamic therapy (PDT) is a common strategy. However, it is difficult to load positively charged photosensitizers and negatively charged adjuvants into the same nanomaterial and further regulate drug release simultaneously. Herein, a single-component dual-functional prodrug strategy is reported for tumor treatment specifically activated by tumor microenvironment (TME)-generated HOCl. A representative prodrug (DHU-CBA2) is constructed using indomethacin grafted with methylene blue (MB). DHU-CBA2 exhibited high sensitivity toward HOCl and achieved simultaneous release of dual drugs in vitro and in vivo. DHU-CBA2 shows effective antitumor activity against lung cancer and spinal metastases via PDT and cyclooxygenase-2 (COX-2) inhibition. Mechanistically, PDT induces immunogenic cell death but stimulates the gene encoding COX-2. Downstream prostaglandins E2 and Indoleamine 2,3 dioxygenase 1 (IDO1) mediate immune escape in the TME, which is rescued by the simultaneous release of indomethacin. DHU-CBA2 promotes infiltration and function of CD8+ T cells, thus inducing a robust antitumor immune response. This work provides an autoboost strategy for a single-component dual-functional prodrug activated by TME-specific HOCl, thereby achieving favorable tumor treatment via the synergistic therapy of PDT and a COX-2 inhibitor.