# Polymer Nanoparticle-Based Photodynamic Therapy Combined with Immunotherapy for Solid Tumor Treatment

## TL;DR

This paper reviews how polymer nanoparticles can be used in combination with immunotherapy to treat solid tumors by enhancing both local tumor destruction and immune system activation.

## Contribution

The paper provides a systematic review of recent advances in polymer nanoparticle design for photo-immunotherapy and their synergistic mechanisms with immunomodulatory agents.

## Key findings

- Polymer nanoparticles enhance local tumor ablation and activate systemic antitumor immune responses.
- Combining photodynamic therapy with immunomodulatory agents like TLR agonists and ICBs shows synergistic effects.
- Challenges in clinical translation and future directions for photo-immunotherapy are outlined.

## Abstract

Polymer nanoparticles have been widely studied for tumor treatment due to their excellent biocompatibility, structural diversity, and multi-functionality. Among their various applications, combining polymer-based photosensitizers with photodynamic therapy (PDT) and immunotherapy has emerged as a promising strategy for treating solid tumors. This combination not only enhances local tumor ablation but also activates systemic antitumor immune responses. Polymer Nanoparticles, with their unique photodynamic properties and ability to integrate multiple therapeutic modalities, offer a powerful platform for photo-immunotherapy. This review systematically discusses recent advances in the design of polymer Nanoparticles and their synergistic mechanisms when combined with immunomodulatory agents such as Toll-like receptor (TLR) agonists, STING agonists, and immune checkpoint inhibitors (ICBs). Moreover, we highlight challenges faced in clinical translation and outline future perspectives for the development of these combination therapies.