Nanomaterial-Based Photothermal Therapy for Inflammatory Diseases: Intervention Strategies, Synergistic Effects, and Future Challenges.

As a fundamental host defense mechanism, the transition from acute to chronic inflammation serves as the foundation for numerous major diseases. Conventional anti-inflammatory interventions are frequently hindered by inadequate bioavailability, instability, and undesirable side effects. High-temperature photothermal therapy (PTT) based on nanomaterials inhibits inflammatory cascades via the precise ablation of activated inflammatory cells, induction of apoptosis, bacterial elimination, and controlled drug release at lesion sites. Meanwhile, mild PTT exerts anti-inflammation through immunomodulation, including regulation of M1/M2 macrophage polarization and upregulation of heat shock proteins (HSPs). These two PTT modalities are complementary in anti‑inflammatory applications, providing more adaptable strategies for precision therapy of inflammatory diseases. This review systematically summarizes strategies to enhance PTT-mediated anti-inflammatory therapy through photothermal nanomaterials, with a particular focus on an emerging paradigm designed to achieve synergistic effects. This review begins with a categorical assessment of current research on inorganic and organic photothermal nanomaterials for anti-inflammatory applications. Building on this, we provide an in-depth analysis of disease-oriented PTT-based anti-inflammatory therapies (e.g. for vascular, articular, and periodontal inflammation), focusing on how engineering design, particularly targeted delivery and multimodal synergistic strategies, enables precise treatment in specific pathological models. Finally, we critically analyze the key challenges in this field, including photodynamic therapy (PDT) side effects, standardization of laser parameters, insufficient light penetration depth, clearance mechanisms, biosafety, and clinical translation. Prospective insights are also provided to guide the development of the next-generation intelligent and efficient photothermal nanoplatforms for anti-inflammatory therapy.