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Phototherapy has garnered worldwide attention for its minimal invasiveness, controllability, and spatial selectivity in treating cancer. One promising approach involves the use of near-infrared dye IR780, which demonstrates both photodynamic therapy (PDT) and photothermal therapy (PTT) effects under 808 nm laser irradiation. However, this hydrophobic dye's toxicity and limited tumor targeting ability severely hamper its suitability for cancer applications. Herein, a biocompatible nanoplatform CoOOH-IR780@BSA (CoIRB) is developed to efficiently deliver IR780 and provide multi-mode treatments for colon tumors. Due to the nanocarrier coating, CoIRB nanoparticles demonstrated reliable dispersion and stability, and their biotoxicity was substantially reduced for safer blood circulation, which overcame the biological barrier of IR780. The nanoplatform has also shown considerable results in phototherapy in vivo and in vitro experiments, with successful inhibition of MC38 tumor growth through intravenous administration. Additionally, the introduction of cobalt ions could induce Fenton-like reactions to activate the production of toxic hydroxyl radicals (˙OH), exerting an assisted chemodynamic therapy (CDT) effect. Notably, these nanodrugs also exhibited potential as scavengers of reductive glutathione (GSH) and hydrogen sulfide (H2S), leading to amplifying oxidative damage of reactive oxygen species (ROS). Overall, the versatile therapeutic platform, CoIRB, has opened up considerable prospects as a biotherapeutic option for combining PDT/PTT/CDT against colon cancer. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI)-guided photothermal therapy (PTT) has recently attracted tremendous attention. In this study, a paramagnetic zwitterionic amphiphilic copolymer (PZAC) was successfully prepared and utilized as a multifunctional surfactant to form micelles in diethylene glycol to coordinate with a molybdenum disulfide precursor (MoS2). Uniform spherical MoS2 nanohybrids (MoS2@PZAC) were first prepared by a microwave-assisted solvothermal process, which is simpler, easier and more efficient than hydrothermal methods or exfoliation processes. In this nanoplatform, MoS2 serves as a phototherapeutic agent possessing a high photothermal conversion efficiency (33.8%), while PZAC acts as a T1-weighted MRI contrast agent. This nanoplatform has the advantages of ultralow toxicity, prolonged circulation time and bio-imaging guided capability. The cytotoxicity assessment showed the good cytocompatibility of MoS2@PZAC. Furthermore, MoS2@PZAC could effectively kill cancer cells upon 2 W cm−2 808 nm laser irradiation for 10 min in both in vitro and in vivo experiments. This work provides a novel and efficient solution to synthesize a multifunctional and uniform theranostic agent, and the results show that the as-prepared MoS2@PZAC can be used as a promising theranostic agent for T1-weighted MRI-guided PTT of cancer cells. [ABSTRACT FROM AUTHOR]

Polypyrrole nanoparticle (PPy) based theranostic agents for magnetic resonance imaging (MRI) guided photothermal therapy (PTT) have received increasing attention in recent years. However, the limitations of cost and biocompability still offer us opportunities to improve these agents. Considering the versatile character of polydopamine (PDA), PEGylated PPy@Fe3+-chelated PDA nanocomposites (PPDEs) were designed and prepared in an easy way. PPDE with a uniform core–shell structure could be obtained by adjusting the ratio of dopamine and PPys. In this nanocomplex, the shells confer the nanoparticles with good biocompability and MRI signal enhancing ability. Moreover, the PPy cores play a role in photothermal ablation of tumors. Compared with pure PDA nanoparticles, the PPDEs have higher NIR absorbance and better photothermal capability benefitting from the high photothermal conversion of the cores. Additionally, the obtained PPDEs provide significant MRI signal enhancement for both in vitro and in vivo imaging with high longitudinal relaxivity (r1 = 5.055 mM−1 s−1). After intravenous injection, the PPDEs exhibited valid tumor accumulation, as revealed by MRI and verified by biodistribution analysis. Under NIR irradiation, the PPDEs showed highly effective photothermal ablation of 4T1 cells. Notably, excellent biocompability of the PPDEs was confirmed by a relevant MTT assay and histologic analysis. This work achieved an example of exploiting the inherent advantages of PPy and PDA within a single unit and exploring its potential for T1 MRI-guided PTT. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI)-guided photothermal therapy (PTT) has recently attracted tremendous attention. In this study, a paramagnetic zwitterionic amphiphilic copolymer (PZAC) was successfully prepared and utilized as a multifunctional surfactant to form micelles in diethylene glycol to coordinate with a molybdenum disulfide precursor (MoS 2 ). Uniform spherical MoS 2 nanohybrids (MoS 2 @PZAC) were first prepared by a microwave-assisted solvothermal process, which is simpler, easier and more efficient than hydrothermal methods or exfoliation processes. In this nanoplatform, MoS 2 serves as a phototherapeutic agent possessing a high photothermal conversion efficiency (33.8%), while PZAC acts as a T 1 -weighted MRI contrast agent. This nanoplatform has the advantages of ultralow toxicity, prolonged circulation time and bio-imaging guided capability. The cytotoxicity assessment showed the good cytocompatibility of MoS 2 @PZAC. Furthermore, MoS 2 @PZAC could effectively kill cancer cells upon 2 W cm -2 808 nm laser irradiation for 10 min in both in vitro and in vivo experiments. This work provides a novel and efficient solution to synthesize a multifunctional and uniform theranostic agent, and the results show that the as-prepared MoS 2 @PZAC can be used as a promising theranostic agent for T 1 -weighted MRI-guided PTT of cancer cells.

Polypyrrole nanoparticle (PPy) based theranostic agents for magnetic resonance imaging (MRI) guided photothermal therapy (PTT) have received increasing attention in recent years. However, the limitations of cost and biocompability still offer us opportunities to improve these agents. Considering the versatile character of polydopamine (PDA), PEGylated PPy@Fe 3+ -chelated PDA nanocomposites (PPDEs) were designed and prepared in an easy way. PPDE with a uniform core-shell structure could be obtained by adjusting the ratio of dopamine and PPys. In this nanocomplex, the shells confer the nanoparticles with good biocompability and MRI signal enhancing ability. Moreover, the PPy cores play a role in photothermal ablation of tumors. Compared with pure PDA nanoparticles, the PPDEs have higher NIR absorbance and better photothermal capability benefitting from the high photothermal conversion of the cores. Additionally, the obtained PPDEs provide significant MRI signal enhancement for both in vitro and in vivo imaging with high longitudinal relaxivity (r 1 = 5.055 mM -1 s -1 ). After intravenous injection, the PPDEs exhibited valid tumor accumulation, as revealed by MRI and verified by biodistribution analysis. Under NIR irradiation, the PPDEs showed highly effective photothermal ablation of 4T1 cells. Notably, excellent biocompability of the PPDEs was confirmed by a relevant MTT assay and histologic analysis. This work achieved an example of exploiting the inherent advantages of PPy and PDA within a single unit and exploring its potential for T 1 MRI-guided PTT.