Image-Guided Cancer Nanomedicine

Biomimetic Ghost Nanomedicine-Based Optotheranostics for Cancer

Theranostic medicine combines diagnostics and therapeutics, focusing on solid tumors at minimal doses. Optically activated photosensitizers are significant examples owing to their photophysical and chemical properties. Several optotheranostics have been tested that convert light to imaging signals, therapeutic radicals, and heat. Upon light exposure, conjugated photosensitizers kill tumor cells by producing reactive oxygen species and heat or by releasing cancer antigens. Despite clinical trials, these molecularly conjugated photosensitizers require protection from their surroundings and a localized direction for site-specific delivery during blood circulation. Therefore, cell membrane biomimetic ghosts have been proposed for precise and safe delivery of these optically active large molecules, which are clinically relevant because of their biocompatibility, long circulation time, bypass of immune cell recognition, and targeting ability. This review focuses on the role of biomimetic nanoparticles in the treatment and diagnosis of tumors through light-mediated diagnostics and therapy, providing insights into their preclinical and clinical status.

Combination of interventional oncology local therapies and immunotherapy for the treatment of hepatocellular carcinoma

Interventional oncology (IO) local therapies of hepatocellular carcinoma (HCC) can activate anti-cancer immunity and it is potentially leading to an anti-cancer immunity throughout the body. For the development of an effective HCC treatment regime, great emphasis has been dedicated to different IO local therapy mediated immune modulation and possible combinations with immune checkpoint inhibitor immunotherapy. In this review paper, we summarize the status of combination of IO local therapy and immunotherapy, as well as the prospective role of therapeutic carriers and locally administered immunotherapy in advanced HCC.

Near-Infrared-II Quantum Dots for In Vivo Imaging and Cancer Therapy

In vivo fluorescence imaging can perform real-time, noninvasive, and high spatiotemporal resolution imaging to accurately obtain the dynamic biological information in vivo, which plays significant roles in the early diagnosis and treatment of cancer. However, traditional in vivo fluorescence imaging usually operates in the visible and near-infrared (NIR)-I windows, which are severely interfered by the strong tissue absorption, tissue scattering, and autofluorescence. The emergence of NIR-II imaging at 1000-1700 nm significantly breaks through the imaging limitations in deep tissues, due to less tissue scattering and absorption. Benefiting from the outstanding optical properties of NIR-II quantum dots (QDs), such as high brightness and good photostability, in vivo fluorescence imaging exhibits excellent temporal-spatial resolution and large penetration depth, and QDs have become a kind of promising fluorescent biomarkers in the field of in vivo fluorescence imaging. Herein, the authors review NIR-II QDs from preparation to modification, and summarize recent applications of NIR-II QDs, including in vivo imaging and imaging-guided therapies. Finally, they discuss the special concerns when NIR-II QDs are shifted from in vivo imaging applications to further in-depth applications.

CD44-targeted, indocyanine green-paclitaxel-loaded human serum albumin nanoparticles for potential image-guided drug delivery

The use of multifunctional nanomedicines for image-guided drug delivery is currently being universally evaluated as a means of efficiently managing cancers and other diseases. In this study we evaluated the potential of an indocyanine green (ICG) and paclitaxel (PTX) loaded human serum albumin (HSA) nanoparticles that was conjugated with hyaluronic acid for use in image-guided drug delivery targeted to CD44-positive non-small cell lung cancer (NSCLC). Series of NSCLC cell lines were evaluated for the expression of CD44 using both western blot analysis and qRT-PCR and compared to a normal lung fibroblast cell line (MRC-5). Using Fluorescence microscopy and photoacoustic imaging (PA), we explored the ability of these targeted nanoparticles to selectively accumulate in NSCLC cell lines in comparison to MRC-5 and their potential for biomedical imaging towards their use for theranostic application. Results obtained suggest that these targeted nanoparticles have potential for application in both imaging and treatment of NSCLC.

Dynamic nanoassemblies of nanomaterials for cancer photomedicine

Photomedicine has long been used for treating cancerous diseases. With advances in chemical and material sciences, various types of light-activated photosensitizers (PSs) have been developed for effective photodynamic therapy (PDT) and photothermal therapy (PTT). However, conventional organic/inorganic materials-based PSs lack disease recognition capability and show limited therapeutic effects in addition to side effects. Recently, intelligent dynamic nanoassemblies that are activated in a tumor environment have been extensively researched to target diseased tissues more effectively, for increasing therapeutic effectiveness while minimizing side effects. This paper presents the latest dynamic nanoassemblies for effective PDT or PTT and combination phototherapies, including immunotherapy and image-guided therapy. Dynamic self-assembly exhibits great potential for clinical translation in diagnosis and treatment through its integrated versatility. Nanoassemblies based on multidisciplinary technology are a promising technique for treating incurable cancerous diseases in the future.

Molecular Imaging-Guided Sonodynamic Therapy

Low-intensity ultrasound-triggered sonodynamic therapy (SDT) is a promising noninvasive therapeutic modality due to its strong tissue penetration ability. In recent years, with the development of nanotechnology, nanoparticle-based sonosensitizer-mediated SDT has been widely investigated. With the increasing demand for precise and personalized treatment, abundant novel sonosensitizers with imaging capabilities have been developed for determining the optimal therapeutic window, thus significantly enhancing treatment efficacy. In this review, we focus on the molecular imaging-guided SDT. The prevalent mechanisms of SDT are discussed, including ultrasonic cavitation, sonoluminescence, reactive oxygen species, and mechanical damage. In addition, we introduce the major molecular imaging techniques and the design principles based on nanoparticles to achieve efficient imaging. Furthermore, the imaging-guided SDT for the treatment of cancer, bacterial infections, and vascular diseases is summarized. The ultimate goal is to design more effective imaging-guided SDT modalities and provide novel ideas for clinical translation of SDT.

The pharmacology of plant virus nanoparticles

The application of nanoparticles for medical purposes has made enormous strides in providing new solutions to health problems. The observation that plant virus-based nanoparticles (VNPs) can be repurposed and engineered as smart bio-vehicles for targeted drug delivery and imaging has launched extensive research for improving the therapeutic and diagnostic management of various diseases. There is evidence that VNPs are promising high value nanocarriers with potential for translational development. This is mainly due to their unique features, encompassing structural uniformity, ease of manufacture and functionalization by means of expression, chemical biology and self-assembly. While the development pipeline is moving rapidly, with many reports focusing on engineering and manufacturing aspects to tailor the properties and efficacy of VNPs, fewer studies have focused on gaining insights into the nanotoxicity of this novel platform nanotechnology. Herein, we discuss the pharmacology of VNPs as a function of formulation and route of administration. VNPs are reviewed in the context of their application as therapeutic adjuvants or nanocarrier excipients to initiate, enhance, attenuate or impede the formulation's toxicity. The summary of the data however also underlines the need for meticulous VNP structure-nanotoxicity studies to improve our understanding of their in vivo fates and pharmacological profiles to pave the way for translation of VNP-based formulations into the clinical setting.

Synergistic Local Combination of Radiation and Anti-Programmed Death Ligand 1 Immunotherapy Using Radiation-Responsive Splintery Metallic Nanocarriers

Radiation therapy (RT)-mediated tumor immunogenicity offers an opportunity for synergistic combination RT and immunotherapy. One of the challenges in the clinic is to attain the optimum efficacy of combination RT and immunotherapy with minimized overlapping toxicities. Here, to achieve synergistic therapeutic efficacy of combinational RT and anti-programmed death ligand 1 (aPD-L1) immunotherapy, RT-responsive splintery snowflake-like Au nanocarriers (S-AuNC) were synthesized with a method for hierarchical bimetallic supra-nanostructures. Primary Au nanocrystals interconnected with Ag nanocrystals in S-AuNC showed RT-responsive structural deformation resulting in RT-triggered release of cargo aPD-LI in S-AuNC. The local combination of RT and aPD-L1 loaded S-AuNC significantly enhanced the immunogenic cell death for tumor microenvironment conversion. RT-triggered local aPD-L1 release allowed a controlled spatiotemporal combination RT and aPD-L1 immunotherapy resulting in a synergistic anticancer adaptive immune response with minimized systemic immune-related adverse effects.

Magnetic field boosted ferroptosis-like cell death and responsive MRI using hybrid vesicles for cancer immunotherapy

We report a strategy to boost Fenton reaction triggered by an exogenous circularly polarized magnetic field (MF) to enhance ferroptosis-like cell-death mediated immune response, as well as endow a responsive MRI capability by using a hybrid core-shell vesicles (HCSVs). HCSVs are prepared by loading ascorbic acid (AA) in the core and poly(lactic-co-glycolic acid) shell incorporating iron oxide nanocubes (IONCs). MF triggers the release of AA, resulting in the increase of ferrous ions through the redox reaction between AA and IONCs. A significant tumor suppression is achieved by Fenton reaction-mediated ferroptosis-like cell-death. The oxidative stress induced by the Fenton reaction leads to the exposure of calreticulin on tumor cells, which leads to dendritic cells maturation and the infiltration of cytotoxic T lymphocytes in tumor. Furthermore, the depletion of ferric ions during treatment enables monitoring of the Fe reaction in MRI-R2* signal change. This strategy provides a perspective on ferroptosis-based immunotherapy.

Emerging Prospects for Nanoparticle-Enabled Cancer Immunotherapy

One of the standards for cancer treatment is cancer immunotherapy which treats both primary and metastasized tumors. Although cancer immunotherapeutics show better outcomes as compared with conventional approaches of cancer treatment, the currently used cancer immunotherapeutics have limited application in delivering cancer antigens to immune cells. Conversely, in solid tumors, tumor microenvironment suppresses the immune system leading to the evasion of anticancer immunity. Some promising attempts have been made to overcome these drawbacks by using different approaches, for instance, the use of biomaterial-based nanoparticles. Accordingly, various studies involving the application of nanoparticles in cancer immunotherapy have been discussed in this review article. This review not only describes the modes of cancer immunotherapy to reveal the importance of nanoparticles in this modality but also narrates nanoparticle-mediated delivery of cancer antigens and therapeutic supplements. Moreover, the impact of nanoparticles on the immunosuppressive behavior of tumor environment has been discussed. The last part of this review deals with cancer immunotherapy using a combination of traditional interventional oncology approach and image-guided local immunotherapy against cancer. According to recent studies, cancer therapy can potentially be improved through nanoparticle-based immunotherapy. In addition, drawbacks associated with the currently used cancer immunotherapeutics can be fixed by using nanoparticles.

Sequential MR Image-Guided Local Immune Checkpoint Blockade Cancer Immunotherapy Using Ferumoxytol Capped Ultralarge Pore Mesoporous Silica Carriers after Standard Chemotherapy

Herein, ferumoxytol (Fer) capped antiprogrammed cell death-ligand 1 (PD-L1) antibodies (aPD-L1) loaded ultralarge pore mesoporous silica nanoparticles (Fer-ICB-UPMSNPs) are formulated for a sequential magnetic resonance (MR) image guided local immunotherapy after cabazitaxel (Cbz) chemotherapy for the treatment of prostate cancer (PC). The highly porous framework of UPMSNP provides a large capacity for aPD-L1. Fer capping of the pores extends the period of aPD-L1 release and provides MR visibility of the aPD-L1 loaded UPMSNP. As-chosen Cbz chemotherapy prior to the local immunotherapy induces strong immunogenic cell death, dendritic cell maturation, and upregulation of PD-L1 of tumor cells. Finally, tumor growth inhibition of sequential MR image-guided local delivery of Fer-ICB-UPMSNPs and a tumor specific adoptive immune reaction are demonstrated in the pretreated Tramp C1 PC mouse model with Cbz chemotherapy. The tumor suppression is superior to those obtained with systemic ICB treatment after Cbz, only Fer-ICB-UPMSNP or only Cbz. As a proof-of concept, MR image-guided local ICB immunotherapy using Fer-ICB-UPMSNPs after chemotherapy suggests a new perspective of translational local immunotherapy for patients who are treated with standard chemotherapies.

Glutathione-Priming Nanoreactors Enable Fluorophore Core/Shell Transition for Precision Cancer Imaging

In an attempt to develop an imaging probe with ultra-high sensitivity for a broad range of tumors in vivo and inspired by the concept of chemical synthetic nanoreactors, we designed a type of glutathione-priming fluorescent nanoreactor (GPN) with an albumin-coating shell and hydrophobic polymer core containing disulfide bonds, protonatable blocks, and indocyanine green (ICG), a near-infrared fluorophore. The albumin played multiple roles including biocompatible carriers, hydrophilic stabilizer, "receptor" of the fluorophores, and even targeting molecules. The protonation of the hydrophobic core triggered the outside-to-core transport of acidic glutathione (GSH), as well as the core-to-shell transference of ICGs after the disulfide bond cleavage by GSH, which induced strong binding of fluorophores with albumins on the GPN shell, initiating intensive fluorescence signals. As a result, the GPNs demonstrated extremely high response sensitivity and imaging contrast, proper time window, and broad cancer specificity. In fact, an orthogonal activation pattern was found in vitro with an ON/OFF ratio up to 24.7-fold. Furthermore, the nanoprobes specifically amplified the tumor signals in five cancer-bearing mouse models and actualized tumor margin delineation with a contrast up to 20-fold, demonstrating much better imaging efficacy than the other four commercially available probes. Therefore, the GPNs provide a new paradigm in developing high-performance bioresponsive nanoprobes.

Decoding Live Cell Interactions with Multi-Nanoparticle Systems: Differential Implications for Uptake, Trafficking, and Gene Regulation

Surface modification with oligonucleotides renders gold nanoparticles to endocytose through very different pathways as compared to unmodified ones. Such oligonucleotide-modified gold nanoparticles (OGNs) have been exploited as effective nanocarriers for gene regulation therapies. Notably, in an effort to reduce overall dosage and provide safer transition to the clinic, cooperative systems composed of two or more discrete nanomaterials have been recently proposed as an alternative to intrinsically multifunctional nanoparticles. Yet, our understanding of such systems designed to synergistically cooperate in their diagnostic or therapeutic functions remains acutely limited. Specifically, cellular interactions and uptake of OGNs are poorly understood when the cell simultaneously interacts with other types of nanoparticles. Here, we investigated the impact of simultaneous uptake of similar-sized iron oxide nanoparticles (IOPs) on the endocytosis and gene regulation function of OGNs, whose analogues have been proposed for sensitization, targeting, and treatment of tumors. We discovered that both the OGN uptake amount and, remarkably, the gene regulation function remained stable when exposed to a very wide range of extracellular concentrations of IOPs. Additionally, the co-localization analysis showed that a proportion of OGNs was co-localized with IOPs inside cells, which hints at the presence of similar trafficking pathways for OGNs and IOPs following endocytosis. Taken together, our observations indicate that while the OGN endocytosis is highly independent of the IOP endocytosis, it shares transport pathways inside cells-but does so without affecting the gene regulation behavior. These results provide key insights into concomitant interactions of cells with diverse nanoparticles and offer a basis for the future design and optimization of cooperative nanomaterials for diverse theranostic applications.

New opportunities for nanoparticles in cancer immunotherapy

BACKGROUND

Recently, cancer immunotherapy has become standard for cancer treatment. Immunotherapy not only treats primary tumors, but also prevents metastasis and recurrence, representing a major advantage over conventional cancer treatments. However, existing cancer immunotherapies have limited clinical benefits because cancer antigens are often not effectively delivered to immune cells. Furthermore, unlike lymphoma, solid tumors evade anti-cancer immunity by forming an immune-suppressive tumor microenvironment (TME). One approach for overcoming these limitations of cancer immunotherapy involves nanoparticles based on biomaterials.

MAIN BODY

Here, we review in detail recent trends in the use of nanoparticles in cancer immunotherapy. First, to illustrate the unmet needs for nanoparticles in this field, we describe the mechanisms underlying cancer immunotherapy. We then explain the role of nanoparticles in the delivery of cancer antigens and adjuvants. Next, we discuss how nanoparticles can be helpful within the immune-suppressive TME. Finally, we summarize current and future uses of nanoparticles with image-guided interventional techniques in cancer immunotherapy.

CONCLUSION

Recently developed approaches for using nanoparticles in cancer immunotherapy have enormous potential for improving cancer treatment. Cancer immunotherapy based on nanoparticles is anticipated not only to overcome the limitations of existing immunotherapy, but also to generate synergistic effects via cooperation between nanoparticles and immune cells.

Photoperiodic Flower Mimicking Metallic Nanoparticles for Image-Guided Medicine Applications

Nanoradiosensitizers have been developed to enhance localization and precision of therapeutic radiation delivery. A specific volume of comprising surface atoms is known to be the radiosensitizing region. However, the shape-dependent local dose enhancement of nanoparticles is often underestimated and rarely reported. Here, a noble metal nanostructure, inspired by the photoperiodic day-flowers, was synthesized by metal reduction with bile acid molecules. The impact of high surface area of day-flower mimicking metallic nanoparticles (D-NP) on radiosensitizing effect was demonstrated with assays for ROS generation, cellular apoptosis, and clonogenic survival of human liver cancer cells (HepG2) cells. In comparison with lower-surface-area spherical night-flower mimicking metallic nanoparticles (N-NP), exposure of our D-NP to external beam radiation doses led to a significant increase in reactive oxygen species (ROS) production and radiosensitizing cell cycle synchronization, resulting in an enhanced cancer-cell-killing effect. In clonogenic survival studies, dose-enhancing factor (DEF) of D-NP was 16.5-fold higher than N-NP. Finally, we demonstrated in vivo feasibility of our D-NP as a potent nanoradiosensitizer and CT contrast agent for advanced image-guided radiation therapy.