Near-infrared photodynamic and photothermal co-therapy based on organic small molecular dyes

Near-infrared (NIR) organic small molecule dyes (OSMDs) are effective photothermal agents for photothermal therapy (PTT) due to their advantages of low cost and toxicity, good biodegradation, and strong NIR absorption over a wide wavelength range. Nevertheless, OSMDs have limited applicability in PTT due to their low photothermal conversion efficiency and inadequate destruction of tumor regions that are nonirradiated by NIR light. However, they can also act as photosensitizers (PSs) to produce reactive oxygen species (ROS), which can be further eradicated by using ROS-related therapies to address the above limitations of PTT. In this review, the synergistic mechanism, composition, and properties of photodynamic therapy (PDT)-PTT nanoplatforms were comprehensively discussed. In addition, some specific strategies for further improving the combined PTT and PDT based on OSMDs for cancer to completely eradicate cancer cells were outlined. These strategies include performing image-guided co-therapy, enhancing tumor infiltration, increasing H2O2 or O2 in the tumor microenvironment, and loading anticancer drugs onto nanoplatforms to enable combined therapy with phototherapy and chemotherapy. Meanwhile, the intriguing prospects and challenges of this treatment modality were also summarized with a focus on the future trends of its clinical application.

Manganese-based hollow nanoplatforms for MR imaging-guided cancer therapies

Theranostic nanoplatforms integrating diagnostic and therapeutic functions have received considerable attention in the past decade. Among them, hollow manganese (Mn)-based nanoplatforms are superior since they combine the advantages of hollow structures and the intrinsic theranostic features of Mn²⁺. Specifically, the hollow cavity can encapsulate a variety of small-molecule drugs, such as chemotherapeutic agents, photosensitizers and photothermal agents, for chemotherapy, photodynamic therapy (PDT) and photothermal therapy (PTT), respectively. After degradation in the tumor microenvironment (TME), the released Mn²⁺ is able to act simultaneously as a magnetic resonance (MR) imaging contrast agent (CA) and as a Fenton-like agent for chemodynamic therapy (CDT). More importantly, synergistic treatment outcomes can be realized by reasonable and optimized design of the hollow nanosystems. This review summarizes various Mn-based hollow nanoplatforms, including hollow Mn_xO_y, hollow matrix-supported Mn_xO_y, hollow Mn-doped nanoparticles, hollow Mn complex-based nanoparticles, hollow Mn-cobalt (Co)-based nanoparticles, and hollow Mn-iron (Fe)-based nanoparticles, for MR imaging-guided cancer therapies. Finally, we discuss the potential obstacles and perspectives of these hollow Mn-based nanotheranostics for translational applications.

Combined Photothermal and Photodynamic Therapy for Cancer Treatment Using a Multifunctional Graphene Oxide

Graphene oxide (GO) is one of the most studied nanomaterials in many fields, including the biomedical field. Most of the nanomaterials developed for drug delivery and phototherapies are based on noncovalent approaches that lead to an unspecific release of physisorbed molecules in complex biological environments. Therefore, preparing covalently functionalized GO using straightforward and versatile methods is highly valuable. Phototherapies, including photothermal therapy (PTT) and photodynamic therapy (PDT), have shown great potential as effective therapeutic approaches against cancer. To overcome the limits of a single method, the combination of PTT and PDT can lead to a combined effect with a higher therapeutic efficiency. In this work, we prepare a folic acid (FA) and chlorin e6 (Ce6) double-functionalized GO for combined targeted PTT/PDT. This conjugate can penetrate rapidly into cancer cells and macrophages. A combined effect of PTT and PDT is observed, leading to a higher killing efficiency toward different types of cells involved in cancer and other diseases. Our work provides a simple protocol to prepare multifunctional platforms for the treatment of various diseases.

A Nanoarchitectonic Approach Enables Triple Modal Synergistic Therapies To Enhance Antitumor Effects

Improvement of antitumor effects relies on the development of biocompatible nanomaterials and combination of various therapies to produce synergistic effects and avoid resistance. In this work, we developed GBD-Fe, a nanoformulation that effectively integrated chemotherapy (CT), chemodynamic therapy (CDT), and photothermal therapy (PTT). GBD-Fe used gold nanorods as photothermal agents and encapsulated doxorubicin to amplify Fe³⁺-guided CDT effects by producing H₂O₂ and reducing the intracellular glutathione levels. In vitro and in vivo experiments were conducted to demonstrate the enhanced accumulation and antitumor effects of this tripronged therapy under magnetic resonance imaging (MRI) guidance. This tripronged approach of CT/CDT/PTT effectively induced tumor cytotoxicity and inhibited tumor growth in tumor-bearing mice and therefore represents a promising strategy to effectively treat tumors.

Multifunctional Hybrid Nanoprobe for Photoacoustic/PET/MR Imaging-Guided Photothermal Therapy of Laryngeal Cancer

Laryngeal cancer is highly aggressive and insensitive to conventional targeted therapies, which often result in poor therapeutic outcomes. Image-guided precision therapy is a promising strategy in oncology that has superior safety and efficacy versus conventional therapies. Here, we present a multifunctional theranostic nanoplatform based on melanin-coated gold nanorod (GNR) that exhibits excellent multimodal imaging ability and photothermal effects. These attributes make the platform applicable for multimodal photoacoustic (PA)/positron emission tomography (PET)/magnetic resonance (MR) image-guided photothermal treatment of laryngeal cancer. The melanin nanoparticles markedly suppress the cytotoxicity of the template cetyltrimethylammonium bromide bilayer and conferred the GNR with excellent PET/MR imaging performances, due to their native biocompatibilities and strong affinities to metal ions. Moreover, the introduction of GNR to the melanin nanoparticles greatly improved the near-infrared absorbances and passive targeting capabilities, leading to exceptional PA imaging and photothermal ablation of tumors. The nanoplatform exhibits high stability and dispersity under physiological conditions. After intravenous injection, the nanoplatform could be precisely tracked in vivo and enabled laryngopharyngeal superficial cancer to be located and imaged. Combined photothermal therapy effectively ablated tumors with negligible side effects. Thus, this work presents a unique and biocompatible nanoplatform that allows multimodal imaging, high anti-tumor PTT efficacy, and negligible side effects in the treatment of laryngeal cancer.

Functional gadolinium-based nanoscale systems for cancer theranostics

Cancer theranostics is a new strategy for combating cancer that integrates cancer imaging and treatment through theranostic agents to provide an efficient and safe way to improve cancer prognosis. Design and synthesis of these cancer theranostic agents are crucial since these agents are required to be biocompatible, tumor-specific, imaging distinguishable and therapeutically efficacious. In this regard, several types of gadolinium (Gd)-based nanomaterials have been introduced to combine different therapeutic agents with Gd to enhance the efficacy of therapeutic agents. At the same time, the entire treatment procedure could be monitored via imaging tools due to incorporation of Gd ions, Gd chelates and Gd/other imaging probes in the theranostic agents. This review aims to overview recent advances in the Gd-based nanomaterials for cancer theranostics and perspectives for Gd nanomaterial-based cancer theranostics are provided.

Synthesis of porphyrin-conjugated silica-coated Au nanorods for synergistic photothermal therapy and photodynamic therapy of tumor

Synergistic therapy of tumor has attracted the attention of an increasing number of researchers because of its higher efficiency compared to single therapy. Herein, 4-carboxyphenyl porphyrin-conjugated silica-coated gold nanorods (AuNR@SiO₂-TCPP) were synthesized. The synergistic treatment of photothermal therapy and photodynamic therapy on A549 cancer was researched in vivo and in vitro. In the AuNR@SiO₂-TCPP, Au NRs and TCPP act as photothermal agent and photosensitizer, respectively. The temperature of the AuNR@SiO₂-TCPP (0.11 nmol L^-1) rises to 56.8 °C for 10 min under the illumination of 808 nm laser (2 Wcm^-2). In MTT assays, the viability of A549 cancer cell treated with AuNR@SiO₂-TCPP (100 μg ml^-1) is only 21%. In animal experiments, the relative tumor volumes in mice receiving AuNR@SiO₂-TCPP (5 mg kg^-1) with 660 and 808 nm irradiations were significantly inhibited and the average value is decreased to 0.78 while the average value of the control group is increased to 7.2. These results demonstrate that the AuNR@SiO₂-TCPP is a potential nanomedicine against tumor for clinical application in the near future.

Sorafenib and indocyanine green co-loaded in photothermally sensitive liposomes for diagnosis and treatment of advanced hepatocellular carcinoma

Sorafenib (SF), as an irreplaceable first-line drug to help advanced hepatocellular carcinoma (HCC) patients to prolong their lives, has already been used in clinical practice for several years. However, this treatment causes several side effects, and few alternatives to SF treatment exist. Herein, we designed NIR fluorescence imaging-guided photothermally sensitive nanoliposomes based on co-encapsulation of SF and the clinical photothermal and photodynamic therapy agent Indocyanine Green (ICG) to solve the problems of SF-based treatment in advanced HCC. As expected, in vitro and in vivo drug release studies on SF-ICG liposomes (SILs) demonstrated SF release from SILs compared with free SF at the same concentration. In addition, in vivo NIR fluorescence imaging and anti-tumor treatment using SILs have been demonstrated by using Hep3B tumor-bearing xenograft nude mice. All detailed experimental evidence suggested that biocompatibility, biotoxicity, and anti-tumor effects were improved by using SILs instead of free SF. In conclusion, our designed SILs could present a novel and suitable SF-based treatment strategy for advanced HCC therapy in the future.

NIR organic dyes based on phenazine-cyanine for photoacoustic imaging-guided photothermal therapy

Two NIR organic dyes based on phenazine-cyanine were successfully assembled with human serum albumin (HSA) forming appropriate size nanoparticles for photoacoustic imaging-guided photothermal therapy.

Microwave-assisted preparation of paramagnetic zwitterionic amphiphilic copolymer hybrid molybdenum disulfide for T1-weighted magnetic resonance imaging-guided photothermal therapy

Magnetic resonance imaging (MRI)-guided photothermal therapy (PTT) has recently attracted tremendous attention.