A new pH/NIR responsive theranostic agent for magnetic resonance imaging guided synergistic therapy

Activatable photothermal agents with target-initiated large spectral separation for highly effective reduction of side effects

Photothermal agents (PTAs) with minimized side effects are critical for transforming cancer photothermal therapy (PTT) into clinical applications. However, most currently available PTAs lack true selective activation to reduce side effects because of heavy spectral overlap between photothermal agents and their corresponding products. This study reports the construction of activatable PTAs with target-initiated large spectral separation for highly effective reduction of side effects. Such designed probes involve two H₂O₂-activatable PTAs, aza-BOD-B1 (single activatable site) and aza-BOD-B2 (multiple activatable site). After interacting with H₂O₂, aza-BOD-B1 only displays a mild absorption redshift (60 nm) from 750 nm to 810 nm with serious spectral overlap, resulting in a mild photothermal effect on normal tissues upon 808 nm light irradiation. In contrast, aza-BOD-B2 displays a large absorption spectral separation (150 nm) from 660 nm to 810 nm, achieving true selective activation to minimize side effects during PTT of cancer. Besides, in vitro and in vivo investigations demonstrated that aza-BOD-B2 can specifically induce photothermal ablation of cancer cells and tumors while leaving normal sites undamaged, whereas aza-BOD-B1 exhibits undesirable side effects on normal cells. Our study provides a practical solution to the problem of undesired side effects of phototherapy, an advance in precision medicine.

Activatable photothermal reagents were designed for cancer therapy. Dual-site-activatable probe showed a large spectral redshift of 150 nm in the presence of H₂O₂, achieving truly selective activation to minimize side effects during PTT of cancers.

Ultrathin 2D Inorganic Ancient Pigment Decorated 3D-Printing Scaffold Enables Photonic Hyperthermia of Osteosarcoma in NIR-II Biowindow and Concurrently Augments Bone Regeneration

Osteosarcoma (OS) is the primary malignant bone tumor. Despite therapeutic strategies including surgery, chemotherapy, and radiotherapy have been introduced into the war of fighting OS, the 5-year survival rate for patients still remains unchangeable for decades. Besides, the critical bone defects after surgery, drug-resistance and side effects also attenuate the therapeutic effects and predict poor prognosis. Recently, photothermal therapy (PTT) has attracted extensive attention featuring minimal invasiveness and high spatial-temporal precision characteristics. Herein, an ultrathin 2D inorganic ancient pigment Egyptian blue decorated 3D-printing scaffold (CaPCu) with profound PTT efficacy at the second near-infrared (NIR-II) biowindow against OS and enhanced osteogenesis performance is successfully constructed. Importantly, this work uncovers the underlying biological mechanisms that genes associated with cell death, proliferation, and bone development are regulated by CaPCu-scaffold-based therapy. This work not only elucidates the fascinating clinical translation prospects of CaPCu-scaffold-based PTT against OS in NIR-II biowindow, but also demonstrates the potential mechanisms and offers a novel strategy to develop the next-generation, multifunctional tissue-engineering biomaterials.