The nonradiative conversion of light energy into heat (photothermal therapy, PTT) or sound energy (photoacoustic imaging, PAI) has been intensively investigated for the treatment and diagnosis of cancer, respectively. By taking advantage of nanocarriers, both imaging and therapeutic functions together with enhanced tumour accumulation have been thoroughly studied to improve the pre-clinical efficiency of PAI and PTT. In this review, we first summarize the development of inorganic and organic nano photothermal transduction agents (PTAs) and strategies for improving the PTT outcomes, including applying appropriate laser dosage, guiding the treatment via imaging techniques, developing PTAs with absorption in the second NIR window, increasing photothermal conversion efficiency (PCE), and also increasing the accumulation of PTAs in tumours. Second, we introduce the advantages of combining PTT with other therapies in cancer treatment. Third, the emerging applications of PAI in cancer-related research are exemplified. Finally, the perspectives and challenges of PTT and PAI for combating cancer, especially regarding their clinical translation, are discussed. We believe that PTT and PAI having noteworthy features would become promising next-generation non-invasive cancer theranostic techniques and improve our ability to combat cancers.

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Photothermal therapy and photoacoustic imaging via nanotheranostics in fighting cancer

The complexity, diversity, and heterogeneity of tumors seriously undermine the therapeutic potential of treatment. Therefore, the current trend in clinical research has gradually shifted from a focus on monotherapy to combination therapy for enhanced treatment efficacy. More importantly, the cooperative enhancement interactions between several types of monotherapy contribute to the naissance of multimodal synergistic therapy, which results in remarkable superadditive (namely “1 + 1 > 2”) effects, stronger than any single therapy or their theoretical combination. In this review, state-of-the-art studies concerning recent advances in nanotechnology-mediated multimodal synergistic therapy will be systematically discussed, with an emphasis on the construction of multifunctional nanomaterials for realizing bimodal and trimodal synergistic therapy as well as the intensive exploration of the underlying synergistic mechanisms for explaining the significant improvements in synergistic therapeutic outcome. Furtherm...

Nanotechnology for Multimodal Synergistic Cancer Therapy

Localized surface plasmon resonance (LSPR) in semiconductor nanocrystals (NCs) that results in resonant absorption, scattering, and near field enhancement around the NC can be tuned across a wide optical spectral range from visible to far-infrared by synthetically varying doping level, and post synthetically via chemical oxidation and reduction, photochemical control, and electrochemical control In this review, we will discuss the fundamental electromagnetic dynamics governing light matter interaction in plasmonic semiconductor NCs and the realization of various distinctive physical properties made possible by the advancement of colloidal synthesis routes to such NCs Here, we will illustrate how free carrier dielectric properties are induced in various semiconductor materials including metal oxides, metal chalcogenides, metal nitrides, silicon, and other materials We will highlight the applicability and limitations of the Drude model as applied to semiconductors considering the complex band structures 

Localized Surface Plasmon Resonance in Semiconductor Nanocrystals

Cellular-membrane-coated nanoparticles have increasingly been pursued to leverage the natural cell functions for enhancing biocompatibility and improved therapeutic efficacy. Taking advantage of specialized cell membranes or combining functions from different membrane types facilitates the strengthening of their functionality. Herein, we fuse membrane materials derived from red blood cells (RBCs) and melanoma cells (B16-F10 cells) to create a hybrid biomimetic coating (RBC–B16), and RBC–B16 hybrid membrane camouflaged doxorubicin (DOX)-loaded hollow copper sulfide nanoparticles (DCuS@[RBC–B16] NPs) are fabricated for combination therapy of melanoma. The DCuS@[RBC–B16] NPs are comprehensively characterized, showing the inherent properties of the both source cells. Compared to the bare CuS NPs, the DCuS@[RBC–B16] NPs exhibit highly specific self-recognition to the source cell line in vitro and achieve markedly prolonged circulation lifetime and enhanced homogeneous targeting abilities in vivo inherited from...

Erythrocyte-Cancer Hybrid Membrane Camouflaged Hollow Copper Sulfide Nanoparticles for Prolonged Circulation Life and Homotypic-Targeting Photothermal/Chemotherapy of Melanoma.

Recent advances of plasmonic nanoparticles include fascinating developments in the fields of energy, catalyst chemistry, optics, biotechnology, and medicine. The plasmonic photothermal properties of metallic nanoparticles are of enormous interest in biomedical fields because of their strong and tunable optical response and the capability to manipulate the photothermal effect by an external light source. To date, most biomedical applications using photothermal nanoparticles have focused on photothermal therapy; however, to fully realize the potential of these particles for clinical and other applications, the fundamental properties of photothermal nanoparticles need to be better understood and controlled, and the photothermal effect-based diagnosis, treatment, and theranostics should be thoroughly explored. This Progress Report summarizes recent advances in the understanding and applications of plasmonic photothermal nanoparticles, particularly for sensing, imaging, therapy, and drug delivery, and discusses the future directions of these fields.

https://onlinelibrary.wiley.com/doi/epdf/10.1002/advs.201900471

Plasmonic Photothermal Nanoparticles for Biomedical Applications

Ultrasmall PEGylated Cu2-x Se nanoparticles with strong near-infrared absorption have been prepared by an ambient aqueous method. The resultant water-soluble and biocompatible nanoparticles are demonstrated to be a novel nanotheranostic agent for effective deep-tissue photoacoustic imaging, computed tomography imaging, single-photon emission computed tomography imaging, and photothermal therapy of cancer.

Ambient Aqueous Synthesis of Ultrasmall PEGylated Cu2−xSe Nanoparticles as a Multifunctional Theranostic Agent for Multimodal Imaging Guided Photothermal Therapy of Cancer

Rapid clearance of nanoagents is a critical criterion for their clinical translation. Herein, it is reported that biodegradable and renal clearable nanoparticles are potentially useful for image-guided photothermal therapy of tumors. The multifunctional nanoparticles with excellent colloidal stability are synthesized through coordination reactions between Fe3+ ions and gallic acid (GA)/polyvinyl pyrrolidone (PVP) in aqueous solution. Detailed characterization reveals that the resulting Fe3+ /GA/PVP complex nanoparticles (FGPNs) integrate strong near-infrared absorption with paramagnetism well. As a result, the FGPNs present outstanding performance for photoacoustic imaging and magnetic resonance imaging of tumors, and outstanding photothermal ablation effect for tumor therapy owing to their high photothermal conversion efficiency. More importantly, the pharmacokinetic behaviors of the FGPNs determined through 125 I labeling suggest that the FGPNs are readily degraded in vivo showing a short biological half-life, and the decomposition products are excreted through either renal clearance pathway or bowel elimination pathway via stomach, which highlights the characteristics of the current multifunctional theranostic agent and their potential in clinical translation.

Biodegradable Nanoagents with Short Biological Half-Life for SPECT/PAI/MRI Multimodality Imaging and PTT Therapy of Tumors

Photothermal Therapy: Ambient Aqueous Synthesis of Ultrasmall PEGylated Cu2−xSe Nanoparticles as a Multifunctional Theranostic Agent for Multimodal Imaging Guided Photothermal Therapy of Cancer (Adv. Mater. 40/2016)

Efficacious cancer treatment largely relies on accurate imaging diagnosis and imaging-guided surgery, which can be achieved by combining different mode imaging probes on one single nanoplatform. Herein, a novel radiolabeled NIR-II nanoprobe (125I-MT NP) was developed to enable versatile single-photon emission computed tomography (SPECT) and second near-infrared (NIR-II) fluorescence dual-modal imaging against breast cancer. 125I-MT was precipitated with an amphiphilic triblock copolymer (PEO-PPO-PEO) to form 125I-MT NPs. The 125I-MT NPs exhibited high labeling efficiency (98 ± 2%) with a hydrodynamic diameter of 91.3 ± 5.5 nm. In vitro and in vivo studies demonstrated that 125I-MT NPs emitted intensive NIR-II fluorescence and SPECT signals, and possessed good biocompatibility. By using a breast tumor xenograft mouse model after intravenous injection of 125I-MT NPs, the SPECT imaging and NIR-II imaging showed clear images of tumor tissues at 8 h and 48 h postinjection, respectively, suggesting the feasibility of using 125I-MT NPs to detect tumors before surgery and visualize the dissection area during surgery. In addition, the SPECT scan of a lymph node mapping was performed at 1 h postinjection and NIR-II fluorescence imaging was carried out at 4 h postinjection. This further guarantees the accurate imaging of lymph nodes before and during surgery for lymphadenectomy. Overall 125I-MT NP is a promising, practical imaging probe for sequential imaging and precision cancer therapy.

Yan Wu

Papers

Ambient Aqueous Synthesis of Ultrasmall PEGylated Cu2−xSe Nanoparticles as a Multifunctional Theranostic Agent for Multimodal Imaging Guided Photothermal Therapy of Cancer

Biodegradable Nanoagents with Short Biological Half-Life for SPECT/PAI/MRI Multimodality Imaging and PTT Therapy of Tumors

Photothermal Therapy: Ambient Aqueous Synthesis of Ultrasmall PEGylated Cu2−xSe Nanoparticles as a Multifunctional Theranostic Agent for Multimodal Imaging Guided Photothermal Therapy of Cancer (Adv. Mater. 40/2016)

Sequential SPECT and NIR-II imaging of tumor and sentinel lymph node metastasis for diagnosis and image-guided surgery.