NIR-driven Smart Theranostic Nanomedicine for On-demand Drug Release and Synergistic Antitumour Therapy

Nanocomposite Hydrogels Based on Poly(vinyl alcohol) and Carbon Nanotubes for NIR-Light Triggered Drug Delivery

Photothermal nanocomposite hydrogels are promising materials for remotely triggering drug delivery by near-infrared (NIR) radiation stimuli. In this work, a novel hydrogel based on poly(vinyl alcohol), poly(vinyl methyl ether-alt-maleic acid), poly(vinyl methyl ether), and functionalized multiwalled carbon nanotubes (MWCNT-f) was prepared by the freeze/thaw method. A comparative characterization of materials (with and without MWCNT-f) was carried out by infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, mechanical assays, swelling kinetics measurements, and photothermal analysis under NIR irradiation. Hydrophilic chemotherapeutic 5-fluorouracil (5-FU) and hydrophobic ibuprofen drugs were independently loaded into hydrogels, and the drug release profiles were obtained under passive and NIR-irradiation conditions. The concentration-dependent cytotoxicity of materials was studied in vitro using noncancerous cells and cancer cells. Notable changes in the microstructure and physicochemical properties of hydrogels were observed by adding a low content (0.2 wt %) of MWCNT-f. The cumulative release amounts of 5-FU and ibuprofen from the hydrogel containing MWCNT-f were significantly increased by 21 and 39%, respectively, through the application of short-term NIR irradiation pulses. Appropriate concentrations of the nanocomposite hydrogel loaded with 5-FU produced cytotoxicity in cancer cells without affecting noncancerous cells. The overall properties of the MWCNT-f-containing hydrogel and its photothermal behavior make it an attractive material to promote the release of hydrophilic and hydrophobic drugs, depending on the treatment requirements.

Development of Robust Cationic Light-Activated Thermosensitive Liposomes: Choosing the Right Lipids

Extensive research has been conducted on cationic light-activated thermosensitive liposomes (CLTSLs) as a means for site-specific and controlled drug release; however, less attention has been given to the stability of these nanoparticles. Selecting the appropriate lipids is crucial for the development of a stable and responsive system. In this study, we investigated the impact of various lipids on the physical properties of cationic light-activated liposomes. Incorporating poly(ethylene glycol) PEG molecules resulted in uniform liposomes with low polydispersity index, while the addition of unsaturated lipid (DOTAP) resulted in extremely leaky liposomes, with almost 80% release in just 10 min of incubation at body temperature. Conversely, the inclusion of cholesterol in the formulation increased liposome stability too much and decreased their sensitivity to stimuli-responsive release, with only 14% release after 2 min of light exposure. To achieve stable and functional CLTSL, we substituted an equivalent amount of unsaturated lipid with a saturated lipid (DPTAP), resulting in stable liposomes at body temperature that were highly responsive to light, releasing 90% of their content in 10 s of light exposure. We also conducted two atomistic molecular dynamics simulations using lipid compositions with saturated and unsaturated lipids to investigate the effect of lipid composition on the dynamical properties of the liposomal lipid bilayer. Our findings suggest that the nature of lipids used to prepare liposomes significantly affects their properties, especially when the drug loading needs to be stable but triggered drug release properties are required at the same time. Selecting the appropriate lipids in the right amount is therefore essential for the preparation of liposomes with desirable properties.

In vitro evaluation of a hybrid drug delivery nanosystem for fibrosis prevention in cell therapy for Type 1 diabetes

Background: Implantation of insulin-secreting cells has been trialed as a treatment for Type 1 diabetes mellitus; however, the host immunogenic response limits their effectiveness. Methodology: The authors developed a core-shell nanostructure of upconversion nanoparticle-mesoporous silica for controlled local delivery of an immunomodulatory agent, MCC950, using near-infrared light and validated it in in vitro models of fibrosis. Results: The individual components of the nanosystem did not affect the proliferation of insulin-secreting cells, unlike fibroblast proliferation (p < 0.01). The nanosystem is effective at releasing MCC950 and preventing fibroblast differentiation (p < 0.01), inflammation (IL-6 expression; p < 0.05) and monocyte adhesion (p < 0.01). Conclusion: This MCC950-loaded nanomedicine system could be used in the future together with insulin-secreting cell implants to increase their longevity as a curative treatment for Type 1 diabetes mellitus.

Erythrocyte-Derived Nanoparticles with Folate Functionalization for Near Infrared Pulsed Laser-Mediated Photo-Chemotherapy of Tumors

Despite its common side effects and varying degrees of therapeutic success, chemotherapy remains the gold standard method for treatment of cancer. Towards developing a new therapeutic approach, we have engineered nanoparticles derived from erythrocytes that contain indocyanine green as a photo-activated agent that enables near infrared photothermal heating, and doxorubicin hydrochloride (DOX) as a chemotherapeutic drug. We hypothesize that milliseconds pulsed laser irradiation results in rapid heating and photo-triggered release of DOX, providing a dual photo-chemo therapeutic mechanism for tumor destruction. Additionally, the surface of the nanoparticles is functionalized with folate to target the folate receptor-α on tumor cells to further enhance the therapeutic efficacy. Using non-contract infrared radiometry and absorption spectroscopy, we have characterized the photothermal response and photostability of the nanoparticles to pulsed laser irradiation. Our in vitro studies show that these nanoparticles can mediate photo-chemo killing of SKOV3 ovarian cancer cells when activated by pulsed laser irradiation. We further demonstrate that this dual photo-chemo therapeutic approach is effective in reducing the volume of tumor implants in mice and elicits an apoptotic response. This treatment modality presents a promising approach in destruction of small tumor nodules.

Mesoporous Polydopamine-Based Nanovehicles as a Versatile Drug Loading Platform to Enable Tumor-Sufficient Synergistic Therapy

The combination of photothermal therapy and chemotherapy are developing as a promising clinical strategy but it urgently needs the high exploration of intelligent multifunctional drug delivery nanovectors. In this paper, we used a versatile method to construct mesoporous polydopamine nanovehicles (MPDA) with the dendritic mesopores loaded with a clinical chemotherapeutic drug, Doxorubicin (MPDA@DOX). The monodisperse nanoagents are spherical with a size of ∼160 nm and pore size of approximately 10 nm. MPDA could efficiently delivery DOX with π-π stacking interaction and acts as the potent photothermal agents. Importantly, MPDA@DOX are preferentially internalized by cancerous cells, then bursting drug release and local hyperthermia generation were observed in conditions representative of the cytoplasm in tumor cells that highly synergistic cell killing effect were found under 808 nm laser irradiation. The fluorescent imaging results of human breast tumor bearing murine model evidenced that MPDA delivery platform have excellent tumor precise targeting effect and in vivo tumor ablation experiment further revealed that MPDA@DOX showed markedly eradicated tumor growth capability under laser exposure. Therefore, this work provided a fascinating strategy based on biocompatible MPDA based drug delivery system for malignant tumors eradication via synergistic therapy.

Photothermally responsive theranostic nanocomposites for near-infrared light triggered drug release and enhanced synergism of photothermo-chemotherapy for gastric cancer

Near-infrared (NIR) photothermal therapy plays a critical role in the cancer treatment and diagnosis as a promising carcinoma treatment modalities nowadays. However, development of clinical application has been greatly limited due to the inefficient drug release and low tumor accumulation. Herein, we designed a NIR-light triggered indocyanine green (ICG)-based PCL core/P(MEO₂MA-b-HMAM) shell nanocomposites (PPH@ICG) and evaluated their therapeutic effects in vitro and in vivo. The anticancer drug 5-fluorouracil (5Fu) and the photothermal agent ICG were loaded into a thermo-sensitive micelle (PPH@5Fu@ICG) by self-assembly. The nanoparticles formed were characterized using transmission electron microscopy, dynamic light scattering, and fluorescence spectra. The thermo-sensitive copolymer (PPH@5Fu@ICG) showed a great temperature-controlled drug release response with lower critical solution temperature. In vitro cellular uptake and TEM imaging proved that PPH@5Fu@ICG nanoparticles can home into the lysosomal compartments under NIR. Moreover, in gastric tumor-bearing nude mice, PPH@5Fu@ICG + NIR group exhibited excellent improvement in antitumor efficacy based on the NIR-triggered thermo-chemotherapy synergy, both in vitro and in vivo. In summary, the proposed strategy of synergistic photo-hyperthermia chemotherapy effectively reduced the 5Fu dose, toxic or side effect, which could serve as a secure and efficient approach for cancer theranostics.

Lipid based nanoparticles as a novel treatment modality for hepatocellular carcinoma: a comprehensive review on targeting and recent advances

Liver cancer is considered one of the deadliest diseases with one of the highest disease burdens worldwide. Among the different types of liver cancer, hepatocellular carcinoma is considered to be the most common type. Multiple conventional approaches are being used in treating hepatocellular carcinoma. Focusing on drug treatment, regular agents in conventional forms fail to achieve the intended clinical outcomes. In order to improve the treatment outcomes, utilizing nanoparticles-specifically lipid based nanoparticles-are considered to be one of the most promising approaches being set in motion. Multiple forms of lipid based nanoparticles exist including liposomes, solid lipid nanoparticles, nanostructured lipid carriers, microemulsion, nanoemulsion, phytosomes, lipid coated nanoparticles, and nanoassemblies. Multiple approaches are used to enhance the tumor uptake as well tumor specificity such as intratumoral injection, passive targeting, active targeting, and stimuli responsive nanoparticles. In this review, the effect of utilizing lipidic nanoparticles is being discussed as well as the different tumor uptake enhancement techniques used.

Combined effect of heat shock protein inhibitor geldanamycin and free radicals on photodynamic therapy of prostate cancer

Prostate cancer is the most common malignancy and the second leading cause of cancer-induced death among men. Recently, photodynamic therapy (PDT) has attracted great attention in prostate cancer treatment because of its high accuracy and no trauma. However, the hypoxic microenvironment of the tumor severely reduces the therapeutic efficacy of oxygen-dependent PDT in prostate cancer, which hampers the generation of reactive oxygen species (ROS). In addition, the PDT process induces the overexpression of pro-survival and anti-apoptotic proteins, thereby reducing the efficacy of PDT. This study proposed a novel multifunctional nanosystem for the targeted delivery of indocyanine green (ICG), 2,2'-azobis[2-(2-imidazolinI-2-yl) propane] dihydrochloride (AIBI), and heat shock protein 90 (Hsp90) inhibitor geldanamycin (17-AAG). Under near-infrared light irradiation, the photothermal effect of ICG induces AIBI decomposition and releases oxygen-independent free radicals, which rescues the hindered ICG-mediated ROS generation. Moreover, 17-AAG reduces heat resistance by inhibiting Hsp90, thereby achieving mild hyperthermia. Simultaneously, the inhibition of Hsp90 can inhibit the overexpression of its client proteins such as anti-apoptotic proteins (survivin) and androgen receptor (AR), thereby improving the efficacy of PDT and inducing prostate cancer cell apoptosis. Results show that the nanosystem enhances PDT by combining free radicals and 17-AAG, exhibiting a good anticancer effect on prostate cancer cells but less toxicity on normal cells.

Therapeutic effects of boronate ester cross-linked injectable hydrogels for the treatment of hepatocellular carcinoma

Hepatocellular carcinoma is the most common malignancy with a high incidence rate and is the leading cause of cancer-related deaths. Herein, we developed a thermo-responsive hydrogel comprising poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide (PCLA) that exhibits acidity-accelerated delivery of the tumor-targeting glucuronic acid-bearing doxorubicin (DOX-pH-GA) conjugate into tumor tissues. The PCLA copolymer was post-modified with boronic acid (BA-PCLA) to covalently cross-link with the pH-responsive DOX-pH-GA conjugate. The BA-PCLA copolymer effectively coordinated with the DOX-pH-GA conjugate through the boronate ester formation and showed a lower critical gelation temperature. The DOX conjugated via boronate ester exhibited a sustained release in vitro. Subcutaneous administration of PCLA copolymers formed in situ gels in the subcutaneous layers of Sprague-Dawley rats and degraded after 6 weeks. Similarly, BA-PCLA copolymers coordinated with DOX-pH-GA formed a stable in situ gel in vivo. In vivo imaging studies demonstrated that DOX-pH-GA was released in a sustained manner. The anti-tumor activity of the DOX releasing injectable hydrogel was examined using a HepG2 liver cancer xenograft model. The in vivo antitumor effect demonstrated that the DOX releasing hydrogel depot remarkably suppresses the tumor growth. These results demonstrate that the pH-responsive DOX releasing thermo-responsive hydrogel depot has great potential for application in localized anticancer therapy.

Cancer Nanotheranostics: A Nanomedicinal Approach for Cancer Therapy and Diagnosis

The panorama of cancer treatment has taken a considerable leap over the last decade with the advancement in the upcoming novel therapies combined with modern diagnostics. Nanotheranostics is an emerging science that holds tremendous potential as a contrivance by integrating therapy and imaging in a single probe for cancer diagnosis and treatment thus offering the advantage like tumor-specific drug delivery and at the same time reduced side effects to normal tissues. The recent surge in nanomedicine research has also paved the way for multimodal theranostic nanoprobe towards personalized therapy through interaction with a specific biological system. This review presents an overview of the nano theranostics approach in cancer management and a series of different nanomaterials used in theranostics and the possible challenges with future directions.

Research advances in integrated theranostic probes for tumor fluorescence visualization and treatment

At present, cancer is obviously a major threat to human health worldwide. Accurate diagnosis and treatment are in great demand and have become an effective method to alleviate the development of cancer and improve the survival rate of patients. A large number of theranostic probes that combine diagnosis and treatment methods have been developed as promising tools for tumor precision medicine. Among them, fluorescent theranostic probes have developed rapidly in the frontier research field of precision medicine with their real time, low toxicity, and high-resolution merit. Therefore, this review focuses on recent advances in the development of fluorescent theranostic probes, as well as their applications for cancer diagnosis and treatment. Initially, small-molecule fluorescent theranostic probes mainly including tumor microenvironment-responsive fluorescent prodrugs and phototherapeutic probes were introduced. Subsequently, nanocomposite probes are expounded based on four types of nano-fluorescent particles combining different therapies (chemotherapy, photothermal therapy, photodynamic therapy, gene therapy, etc.). Then, the capsule-type "all in one" probes, which occupy an important position in theranostic probes, are summarized according to the surface carrier type. This review aims to present a comprehensive guide for researchers in the field of tumor-related theranostic probe design and development.

Doxorubicin-loaded pH-responsive nanoparticles coated with chlorin e6 for drug delivery and synergetic chemo-photodynamic therapy

The integration of chemotherapy drugs and photosensitizers to form versatile nanoplatforms for achieving chemo-photodynamic synergetic therapy has shown great superiority in tumor theranostic applications. We constructed pH-responsive nanoparticles (DOX/PB NPs) encapsulating the chemotherapeutic drug doxorubicin (DOX) into the cores of PLGA NPs coated with bovine serum albumin (BSA) via a water-in-oil (W/O/W) emulsion method. A simple and efficient chemo-photodynamic synergetic nanoplatform (DOX/PB@Ce6 NPs) was obtained by the adsorption of photosensitizer chlorin e6 (Ce6) onto the surface of the DOX/PB NPs. With optimal size, pH-responsive drug release behavior and excellent singlet oxygen production, the DOX/PB@Ce6 NPs have the potential to enhance anti-tumor efficiency. The cellular uptake, cytotoxicity, chemo-photodynamic synergetic effect and biocompatibility of the NPs were evaluated based on HeLa cells via in vitro experiments. The in vitro chemo-photodynamic synergetic experiments indicated that the DOX/PB@Ce6 NPs had remarkable cancer cell killing efficiency under laser irradiation. Notably, by hemolysis assay, all the NPs displayed excellent blood compatibility and were expected to be applicable for intravenous injection. In summary, the designed DOX/PB@Ce6 NPs multifunctional theranostic nanoplatform had excellent reactive oxygen species generation and would be a potential therapeutic platform for chemo-photodynamic synergetic therapy.

Osteotropic Radiolabeled Nanophotosensitizer for Imaging and Treating Multiple Myeloma

Rapid liver and spleen opsonization of systemically administered nanoparticles (NPs) for in vivo applications remains the Achilles' heel of nanomedicine, allowing only a small fraction of the materials to reach the intended target tissue. Although focusing on diseases that reside in the natural disposal organs for nanoparticles is a viable option, it limits the plurality of lesions that could benefit from nanomedical interventions. Here we designed a theranostic nanoplatform consisting of reactive oxygen (ROS)-generating titanium dioxide (TiO2) NPs, coated with a tumor-targeting agent, transferrin (Tf), and radiolabeled with a radionuclide (89Zr) for targeting bone marrow, imaging the distribution of the NPs, and stimulating ROS generation for cell killing. Radiolabeling of TiO2 NPs with 89Zr afforded thermodynamically and kinetically stable chelate-free 89Zr-TiO2-Tf NPs without altering the NP morphology. Treatment of multiple myeloma (MM) cells, a disease of plasma cells originating in the bone marrow, with 89Zr-TiO2-Tf generated cytotoxic ROS to induce cancer cell killing via the apoptosis pathway. Positron emission tomography/X-ray computed tomography (PET/CT) imaging and tissue biodistribution studies revealed that in vivo administration of 89Zr-TiO2-Tf in mice leveraged the osteotropic effect of 89Zr to selectively localize about 70% of the injected radioactivity in mouse bone tissue. A combination of small-animal PET/CT imaging of NP distribution and bioluminescence imaging of cancer progression showed that a single-dose 89Zr-TiO2-Tf treatment in a disseminated MM mouse model completely inhibited cancer growth at euthanasia of untreated mice and at least doubled the survival of treated mice. Treatment of the mice with cold Zr-TiO2-Tf, 89Zr-oxalate, or 89Zr-Tf had no therapeutic benefit compared to untreated controls. This study reveals an effective radionuclide sensitizing nanophototherapy paradigm for the treatment of MM and possibly other bone-associated malignancies.

Smart gold nanocages for mild heat-triggered drug release and breaking chemoresistance

Chemotherapy is an important modality available for cancer treatment. However, the present chemotherapy is still far from being satisfactory mainly owing to the severe side effects of the chemotherapeutic agents and drug resistance of cancer cells. Thus, reversing drug resistance by constructing an ideal chemotherapeutic strategy with the least side effects and the best efficacy is greatly needed. Here, we designed a smart nanosystem of thermo-sensitive liposome coated gold nanocages with doxorubicin (DOX) loading (LAD) for near-infrared (NIR)-triggered drug release and chemo-photothermal combination therapy. The biocompatible liposomes coating facilitated the cellular uptake of LAD and meanwhile avoided drug leakage during the circulation. More importantly, LAD exhibited controllable photothermal conversion property and produced mild heat under NIR irradiation, which not only triggered DOX release and transferred DOX from lysosome to nucleus, but also elicited the mild heat cell killing effect to improve the curative efficiency. Further mechanism study revealed that mild heat could reverse drug resistance by down-regulation of the chemoresistance-related markers (e.g., HSF-1, p53, P-gp), and inhibited DOX export and increased drug sensitiveness, thereby prominently increased the anticancer efficiency. This versatile nanoplatform with enhanced curative efficacy and lower side effect is promising to apply in the field of drug controlled release and combination tumor therapy.

Intravesical device-assisted therapies for non-muscle-invasive bladder cancer

Non-muscle-invasive bladder cancer (NMIBC), the most prevalent type of bladder cancer, accounts for ~75% of bladder cancer diagnoses. This disease has a 50% risk of recurrence and 20% risk of progression within 5 years, despite the use of intravesical adjuvant treatments (such as BCG or mitomycin C) that are recommended by clinical guidelines. Intravesical device-assisted therapies, such as radiofrequency-induced thermochemotherapeutic effect (RITE), conductive hyperthermic chemotherapy, and electromotive drug administration (EMDA), have shown promising efficacy. These device-assisted treatments are an attractive alternative to BCG, as issues with supply have been a problem in some countries. RITE might be an effective treatment option for some patients who have experienced BCG failure and are not candidates for radical cystectomy. Data from trials using EMDA suggest that it is effective in high-risk disease but requires further validation, and results of randomized trials are eagerly awaited for conductive hyperthermic chemotherapy. Considerable heterogeneity in patient cohorts, treatment sessions, use of maintenance regimens, and single-arm study design makes it difficult to draw solid conclusions, although randomized controlled trials have been reported for RITE and EMDA.

Near-infrared light activatable hydrogels for metformin delivery

Drug loaded hydrogels have proven to be versatile controlled-release systems. We report here on heat active hydrogel formation by mixing graphene oxide (GO) or carboxyl enriched reduced graphene oxide (rGO-COOH) with metformin hydrochloride, an insulin sensitizer drug currently used as the first line therapy to treat patients with type 2 diabetes. The driving forces of the gelation process between the graphene-based nanomaterial and metformin are hydrogen bonding and electrostatic interactions, weakened at elevated temperature. Using the excellent photothermal properties of the graphene matrixes, we demonstrate that these supramolecular drug reservoirs can be photothermally activated for transdermal metformin delivery. A sustained delivery of metformin was achieved using a laser power of 1 W cm-2. In vitro assessment of the key target Glucose-6 Phosphatase (G6P) gene expression using a human hepatocyte model confirmed that metformin activity was unaffected by photothermal activation. In vivo, metformin was detected in mice plasma at 1 h post-activation of the metformin loaded rGO-COOH gel.

Design of Soft Nanocarriers Combining Hyaluronic Acid with Another Functional Polymer for Cancer Therapy and Other Biomedical Applications

The rapid advancement in medicine requires the search for new drugs, but also for new carrier systems for more efficient and targeted delivery of the bioactive molecules. Among the latter, polymeric nanocarriers have an increasingly growing potential for clinical applications due to their unique physical and chemical characteristics. In this regard, nanosystems based on hyaluronic acid (HA), a polysaccharide which is ubiquitous in the body, have attracted particular interest because of the biocompatibility, biodegradability and nonimmunogenic property provided by HA. Furthermore, the fact that hyaluronic acid can be recognized by cell surface receptors in tumor cells, makes it an ideal candidate for the targeted delivery of anticancer drugs. In this review, we compile a comprehensive overview of the different types of soft nanocarriers based on HA conjugated or complexed with another polymer: micelles, nanoparticles, nanogels and polymersomes. Emphasis is made on the properties of the polymers used as well as the synthetic approaches for obtaining the different HA-polymer systems. Fabrication, characterization and potential biomedical applications of the nanocarriers will also be described.

Bioinspired Multivalent Peptide Nanotubes for Sialic Acid Targeting and Imaging-Guided Treatment of Metastatic Melanoma

Tumor metastasis is considered a major cause of cancer-related human mortalities. However, it still remains a formidable challenge in clinics. Herein, a bioinspired multivalent nanoplatform for the highly effective treatment of the metastatic melanoma is reported. The versatile nanoplatform is designed by integrating indocyanine green and a chemotherapeutic drug (7-ethyl-10-hydroxycamptothecin) into phenylboronic acid (PBA)-functionalized peptide nanotubes (termed as I/S-PPNTs). I/S-PPNTs precisely target tumor cells through multivalent interaction between PBA and overexpressed sialic acid on the tumor surface in order to achieve imaging-guided combination therapy. It is demonstrated that I/S-PPNTs are efficiently internalized by the B16-F10 melanoma cells in vitro in a PBA grafting density-dependent manner. It is further shown that I/S-PPNTs specifically accumulate and deeply penetrate into both the subcutaneous and lung metastatic B16-F10 melanoma tumors. More importantly, I/S-PPNT-mediated combination chemo- and photodynamic therapy efficiently eradicates tumor and suppresses the lung metastasis of B16-F10 melanoma in an immunocompetent C57BL/6 mouse model. The results highlight the promising potential of the multivalent peptide nanotubes for active tumor targeting and imaging-guided cancer therapy.

Nanocapsules for Programmed Neurotransmitter Release: Toward Artificial Extracellular Synaptic Vesicles

Nanocapsules present a promising platform for delivering chemicals and biomolecules to a site of action in a living organism. Because the biological action of the encapsulated molecules is blocked until they are released from the nanocapsules, the encapsulation structure enables triggering of the topical and timely action of the molecules at the target site. A similar mechanism seems promising for the spatiotemporal control of signal transduction triggered by the release of signal molecules in neuronal, metabolic, and immune systems. From this perspective, nanocapsules can be regarded as practical tools to apply signal molecules such as neurotransmitters to intervene in signal transduction. However, spatiotemporal control of the payload release from nanocapsules persists as a key technical issue. Stimulus-responsive nanocapsules that release payloads in response to external input of physical stimuli are promising platforms to enable programmed payload release. These programmable nanocapsules encapsulating neurotransmitters are expected to lead to new insights and perspectives related to artificial extracellular synaptic vesicles that might provide an experimental and therapeutic strategy for neuromodulation and nervous system disorders.

Multifunctional Thermosensitive Liposomes Based on Natural Phase-Change Material: Near-Infrared Light-Triggered Drug Release and Multimodal Imaging-Guided Cancer Combination Therapy

Multifunctional theranostic nanoplatforms (NPs) in response to environment stimulations for on-demand drug release are highly desirable. Herein, the near-infrared (NIR)-absorbing dye, indocyanine green (ICG), and the antitumor drug, doxorubicin (DOX), were efficiently coencapsulated into the thermosensitive liposomes based on natural phase-change material. Folate and conjugated gadolinium (Gd) chelate-modified liposome shells enhance active targeting and magnetic resonance performance of the NPs while maintaining the size of the NPs. The ICG/DOX-loaded and gadolinium chelate conjugated temperature-sensitive liposome nanoplatforms (ID@TSL-Gd NPs) exhibited NIR-triggered drug release and prominent chemo-, photothermal, and photodynamic therapy properties. With the coencapsulated ICG, DOX, and the conjugated gadolinium chelates, the ID@TSL-Gd NPs can be used for triple-modal imaging (fluorescence/photoacoustic/magnetic resonance imaging)-guided combination tumor therapy (chemotherapy, photothermotherapy, and photodynamic therapy). After tail vein injection, the ID@TSL-Gd NPs accumulated effectively in subcutaneous HeLa tumor of mice. The tumor was effectively suppressed by accurate imaging-guided NIR-triggered phototherapy and chemotherapy, and no tumor regression and side effects were observed. In summary, the prepared ID@TSL-Gd NPs achieved multimodal imaging-guided cancer combination therapy, providing a promising platform for improving diagnosis and treatment of cancer.

Graphene-Based Smart Platforms for Combined Cancer Therapy

The extensive research of graphene and its derivatives in biomedical applications during the past few years has witnessed its significance in the field of nanomedicine. Starting from simple drug delivery systems, the application of graphene and its derivatives has been extended to a versatile platform of multiple therapeutic modalities, including photothermal therapy, photodynamic therapy, magnetic hyperthermia therapy, and sonodynamic therapy. In addition to monotherapy, graphene-based materials are widely applied in combined therapies for enhanced anticancer activity and reduced side effects. In particular, graphene-based materials are often designed and fabricated as "smart" platforms for stimuli-responsive nanocarriers, whose therapeutic effects can be activated by the tumor microenvironment, such as acidic pH and elevated glutathione (termed as "endogenous stimuli"), or light, magnetic, or ultrasonic stimuli (termed as "exogenous stimuli"). Herein, the recent advances of smart graphene platforms for combined therapy applications are presented, starting with the principle for the design of graphene-based smart platforms in combined therapy applications. Next, recent advances of combined therapies contributed by graphene-based materials, including chemotherapy-based, photothermal-therapy-based, and ultrasound-therapy-based synergistic therapy, are outlined. In addition, current challenges and future prospects regarding this promising field are discussed.

Clinical Trials of Thermosensitive Nanomaterials: An Overview

Currently, we are facing increasing demand to develop efficient systems for the detection and treatment of diseases that can realistically improve distinct aspects of healthcare in our society. Sensitive nanomaterials that respond to environmental stimuli can play an important role in this task. In this manuscript, we review the clinical trials carried out to date on thermosensitive nanomaterials, including all those clinical trials in hybrid nanomaterials that respond to other stimuli (e.g., magnetic, infrared radiation, and ultrasound). Specifically, we discuss their use in diagnosis and treatment of different diseases. At present, none of the existing trials focused on diagnosis take advantage of the thermosensitive characteristics of these nanoparticles. Indeed, almost all clinical trials consulted explore the use of Ferumoxytol as a current imaging test enhancer. However, the thermal property is being further exploited in the field of disease treatment, especially for the delivery of antitumor drugs. In this regard, ThermoDox®, based on lysolipid thermally sensitive liposome technology to encapsulate doxorubicin (DOX), is the flagship drug. In this review, we have evidenced the discrepancy existing between the number of published papers in thermosensitive nanomaterials and their clinical use, which could be due to the relative novelty of this area of research; more time is needed to validate it through clinical trials. We have no doubt that in the coming years there will be an explosion of clinical trials related to thermosensitive nanomaterials that will surely help to improve current treatments and, above all, will impact on patients' quality of life and life expectancy.

The synthesis and application of nano doxorubicin- indocyanine green matrix metalloproteinase-responsive hydrogel in chemophototherapy for head and neck squamous cell carcinoma

Background

Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignancies, with high rates of mortality and morbidity worldwide. Owing to the special anatomical location of this tumor, an effective, minimally invasive treatment with low systemic toxicity is highly desirable. Hydrogels have shown great potential for tumor-targeting therapy, with excellent performance. However, there have been few reports on co-loading photosensitizers and chemotherapeutic drugs into hydrogels. In this study, we synthesized a nano doxorubicin-indocyanine green matrix metalloproteinase (MMP)-responsive hydrogel (denoted as NDIMH), combining chemotherapy and phototherapy, to achieve superior antitumor efficacy.

Methods

First, NDIMH was synthesized and characterized by scanning electron microscopy and drug-release assays. Second, the photosensitivity properties and antitumor efficiency of this drug delivery system were studied in vivo and in vitro. Last, the imaging and biodistribution of NDIMH were monitored using the Maestro EX in vivo imaging system.

Results

The nanodrugs loaded into the smart hydrogel exhibited uniform size distribution, excellent size stability, and a sustained release in the presence of MMP-2. NDIMH showed ideal photosensitivity characteristics under light. NDIMH with 808 nm near-infrared (NIR) irradiation effectively inhibited the viability, invasion, and metastasis of SCC-15 in vitro. After intratumoral injection of NDIMH with 808 nm NIR illumination, the hydrogels exhibited favorable synergistic antitumor efficacy and acceptable biosafety. Additionally, fluorescence imaging showed that NDIMH could significantly improve the retention of nanodrugs at the tumor site.

Conclusion

The intratumoral injection of NDIMH with 808 nm NIR irradiation could be a promising chemophototherapy alternative for HNSCC.

Current Trends in Cancer Nanotheranostics: Metallic, Polymeric, and Lipid-Based Systems

Theranostics has emerged in recent years to provide an efficient and safer alternative in cancer management. This review presents an updated description of nanotheranostic formulations under development for skin cancer (including melanoma), head and neck, thyroid, breast, gynecologic, prostate, and colon cancers, brain-related cancer, and hepatocellular carcinoma. With this focus, we appraised the clinical advantages and drawbacks of metallic, polymeric, and lipid-based nanosystems, such as low invasiveness, low toxicity to the surrounding healthy tissues, high precision, deeper tissue penetration, and dosage adjustment in a real-time setting. Particularly recognizing the increased complexity and multimodality in this area, multifunctional hybrid nanoparticles, comprising different nanomaterials and functionalized with targeting moieties and/or anticancer drugs, present the best characteristics for theranostics. Several examples, focusing on their design, composition, imaging and treatment modalities, and in vitro and in vivo characterization, are detailed herein. Briefly, all studies followed a common trend in the design of these theranostics modalities, such as the use of materials and/or drugs that share both inherent imaging (e.g., contrast agents) and therapeutic properties (e.g., heating or production reactive oxygen species). This rationale allows one to apparently overcome the heterogeneity, complexity, and harsh conditions of tumor microenvironments, leading to the development of successful targeted therapies.

Laser-Induced Transformable BiS@HSA/DTX Multiple Nanorods for Photoacoustic/Computed Tomography Dual-Modal Imaging Guided Photothermal/Chemo Combinatorial Anticancer Therapy

Suboptimal intratumor accumulation and poorly controllable release of encapsulated drugs remain unresolved challenges hampering further advancement of nanomedicines in cancer therapy. Herein, we conceived near-infrared (NIR) laser-triggered transformable BiS@HSA/DTX multiple nanorods (mNRs), which were made of small bundles of bismuth sulfide nanorods (BiS NRs) coated with docetaxel (DTX)-inlaid human serum albumin (HSA). The BiS@HSA/DTX mNRs had a lateral size of approximately 100 nm and efficiently accumulated in the tumor microenvironment upon systemic administration in tumor-bearing nude mice. NIR laser irradiation of the tumor area caused rapid disassembly of the BiS@HSA/DTX mNRs into individual HSA-coated BiS nanorods (BiS@HSA iNRs) and triggered the release of DTX from the HSA corona, due to the local temperature increase generated by BiS NRs via the photothermal effect. The laser-induced transformation into BiS@HSA iNRs facilitated their penetration and increased the retention time in tumor. The spatiotemporal delivery behavior of the BiS@HSA/DTX mNRs could be monitored by photoacoustic/computed tomography dual-modal imaging in vivo. Furthermore, because of the excellent photothermal conversion properties of BiS NRs and laser-triggered DTX release from BiS@HSA/DTX mNRs, efficient tumor combinatorial therapy was achieved via concurrent hyperthermia and chemotherapy in mice treated with BiS@HSA/DTX mNRs upon NIR laser irradiation.

Short duration cancer treatment: inspired by a fast bio-resorbable smart nano-fiber device containing NIR lethal polydopamine nanospheres for effective chemo-photothermal cancer therapy

BACKGROUND

The objective of this study was to evaluate the efficacy of a combination of Photothermal therapy (PTT) and chemotherapy in a single nano-fiber platform containing lethal polydopamine nanopheres (PD NPs) for annihilation of CT 26 cancer cells.

METHOD

Polydioxanone (PDO) nanofiber containing PD and bortezomib (BTZ) was fabricated via electrospinning method. The content of BTZ and PD after optimization was 7% and 2.5% respectively with respect to PDO weight. PD NPs have absorption band in near-infrared (NIR) with resultant rapid heating capable of inducing cancer cell death. The samples was divided into three groups - PDO, PDO+PD, and PDO+PD-BTZ for analysis.

RESULTS

In combined treatment, PDO nanofiber alone could not inhibit cancer cell growth as it neither contain PD or BTZ. However, PDO+PD fiber showed a cell viability of approximately 20% after 72 hr of treatment indicating minimal killing via hyperthermia. In the case of PDO composite fiber containing BTZ, the effect of NIR irradiation reduced the viability of cancer cells down to around 5% after 72 h showing the efficiency of combination therapy on cancer cells elimination. However, due to higher photothermal conversion that may negatively affect normal cells above 46°C, we have employed 1 s "OFF" and 2 s "ON" after initial 9 s continuous irradiation to maintain the temperature between 42 and 46°C over 3 mins of treatment using 2 W/cm2; 808 nm laser which resulted to similar cell death.

CONCLUSION

In this study, combination of PTT and chemotherapy treatment on CT 26 colon cancer cells within 3 min resulted in effective cell death in contrast to single treatment of either PTT and chemotherapy alone. Our results suggest that this nanofiber device with efficient heating and remote control drug delivery system can be useful and convenient in the future clinical application for localized cancer therapy.

Development of redox-responsive theranostic nanoparticles for near-infrared fluorescence imaging-guided photodynamic/chemotherapy of tumor

The development of imaging-guided smart drug delivery systems for combinational photodynamic/chemotherapy of the tumor has become highly demanded in oncology. Herein, redox-responsive theranostic polymeric nanoparticles (NPs) were fabricated innovatively using low molecular weight heparin (LWMH) as the backbone. Chlorin e6 (Ce6) and alpha-tocopherol succinate (TOS) were conjugated to LMWH via cystamine as the redox-sensitive linker, forming amphiphilic Ce6-LMWH-TOS (CHT) polymer, which could self-assemble into NPs in water and encapsulate paclitaxel (PTX) inside the inner core (PTX/CHT NPs). The enhanced near-infrared (NIR) fluorescence intensity and reactive oxygen species (ROS) generation of Ce6 were observed in a reductive environment, suggesting the cystamine-switched "ON/OFF" of Ce6. Also, the in vitro release of PTX exhibited a redox-triggered profile. MCF-7 cells showed a dramatically higher uptake of Ce6 delivered by CHT NPs compared with free Ce6. The improved therapeutic effect of PTX/CHT NPs compared with mono-photodynamic or mono-chemotherapy was observed in vitro via MTT and apoptosis assays. Also, the PTX/CHT NPs exhibited a significantly better in anti-tumor efficiency upon NIR irradiation according to the results of in vivo combination therapy conducted on 4T1-tumor-bearing mice. The in vivo NIR fluorescence capacity of CHT NPs was also evaluated in tumor-bearing nude mice, implying that the CHT NPs could enhance the accumulation and retention of Ce6 in tumor foci compared with free Ce6. Interestingly, the anti-metastasis activity of CHT NPs was observed against MCF-7 cells by a wound healing assay, which was comparable to LMWH, suggesting LMWH was promising for construction of nanocarriers for cancer management.

Dual pH/reduction-responsive hybrid polymeric micelles for targeted chemo-photothermal combination therapy

The combination of chemotherapy and photothermal therapy in multifunctional nanovesicles has emerged as a promising strategy to improve cancer therapeutic efficacy. Herein, we designed new pH/reduction dual-responsive and folate decorated polymeric micelles (FA Co-PMs) as theranostic nanocarrier to co-encapsulate doxorubicin (DOX) and indocyanine green (ICG) for targeted NIR imaging and chemo-photothermal combination therapy. The Co-PMs exhibited nano-sized structure (∼100 nm) with good monodispersity, high encapsulation efficiency of both ICG and DOX, triggered DOX release in response to acid pH and reduction environment, and excellent temperature conversion with laser irradiation. In vitro cellular uptake study indicated FA Co-PMs achieved significant targeting to BEL-7404 cells via folate receptor-mediated endocytosis, and laser-induced hyperthermia further enhanced drug accumulation into cancer cells. In vivo biodistribution study indicated that FA Co-PMs prolonged drug circulation and enhanced drug accumulation into the tumor via EPR effect and FA targeting. Furthermore, the ICG-based photo-triggered hyperthermia combined with DOX-based chemotherapy synergistically induced the BEL-7404 cell death and apoptosis, and efficiently suppressed the BEL-7404 xenografted tumor growth while significantly reduced systemic toxicity in vivo. Therefore, the designed dual-responsive Co-PMs were promising theranostic nanocarriers for versatile antitumor drug delivery and imaging-guided cancer chemo-photothermal combination therapy.

STATEMENT OF SIGNIFICANCE

The combination of chemotherapy and photothermal therapy in multifunctional nanovesicles has emerged as a promising strategy to improve cancer therapeutic efficacy. Herein, we designed novel pH/reduction dual-responsive and folate decorated polymeric micelles (FA Co-PMs) as theranostic nanocarrier to co-encapsulate doxorubicin (DOX) and indocyanine green (ICG) for targeted NIR imaging and chemo-photothermal combination therapy. The Co-PMs triggered DOX release in response to acid pH and reduction environment and exhibited excellent temperature conversion with laser irradiation. The results indicated FA Co-PMs achieved significant targeting to BEL-7404 cells in vitro and efficiently suppressed the BEL-7404 xenografted tumor growth while significantly reduced systemic toxicity in vivo. Therefore, the designed dual-responsive Co-PMs displayed great potential in imaging-guided cancer chemo-photothermal combination therapy as theranostic nanocarriers.

Folic acid modified cell membrane capsules encapsulating doxorubicin and indocyanine green for highly effective combinational therapy in vivo

A combination of chemotherapy and phototherapy has emerged as a promising strategy for cancer treatment. To achieve effective combinational therapy of cancer with reduced toxicity, it is highly desirable to improve the targeting of chemotherapeutic and near-infrared photosensitizers to enhance their accumulation in tumor. Here we report a novel tumor targeting cell membrane capsule (CMC), originate from living cells, to load doxorubicin hydrochloride (DOX) and indocyanine green (ICG), for combinational photo-chemotherapy against cancer. As a result, folic acid modified CMC (CMC-FA, with a diameter about 200 nm and a FA density of 0.4 molecule/nm²) showed 3-4 fold higher cell uptake by cancer cells in vitro and 2.3 times higher accumulation in mouse cancer xenografts in vivo than pristine CMC. DOX and ICG with therapeutically significant concentrations can be sequentially encapsulated into CMC-FA by temporary permeating the plasma membranes with high efficiency. The systematic administration of cancer targeting CMC-FA loaded with DOX and ICG could significantly inhibit tumor growth in mouse xenografts in the presence of a near-infrared light at 808 nm, without noticeable toxicity. These findings suggest that cancer targeting CMC may have considerable benefits in drug delivery and combinational cancer therapy.

STATEMENT OF SIGNIFICANCE

A combination of chemotherapy and photothermal/photodynamic therapy has emerged as a promising strategy for cancer therapy. In current study, a novel cancer targeting cell membrane capsule (CMC-FA), originate from living cells and surface modified with folic acid, was developed to load doxorubicin hydrochloride (DOX) and indocyanine green (ICG), for combinational photo-chemotherapy against cancer. The systematic administration of drug loaded CMC-FA can significantly inhibit tumor growth in mouse xenografts in the presence of a near-infrared light at 808 nm, without noticeable toxicity. This study provides a simple and robust strategy to develop biocompatible therapeutic cell membrane capsules, holds strong translational potential in precise cancer treatment.

Tumor-targeted hybrid protein oxygen carrier to simultaneously enhance hypoxia-dampened chemotherapy and photodynamic therapy at a single dose

Hypoxia is a characteristic feature of solid tumors and an important causation of resistance to chemotherapy and photodynamic therapy (PDT). It is challenging to develop efficient functional nanomaterials for tumor oxygenation and therapeutic applications.

Methods: Through disulfide reconfiguration to hybridize hemoglobin and albumin, tumor-targeted hybrid protein oxygen carriers (HPOCs) were fabricated, serving as nanomedicines for precise tumor oxygenation and simultaneous enhancement of hypoxia-dampened chemotherapy and photodynamic therapy. Based on encapsulation of doxorubicin (DOX) and chlorin e6 (Ce6) into HPOCs to form ODC-HPOCs, the mechanism and therapeutic efficacy of oxygen-enhanced chemo-PDT was investigated in vitro and in vivo.

Results: The precise oxygen preservation and release of the HPOC guaranteed sufficient tumor oxygenation, which is able to break hypoxia-induced chemoresistance by downregulating the expressions of hypoxia-inducible factor-1α (HIF-1α), multidrug resistance 1 (MDR1) and P-glycoprotein (P-gp), resulting in minimized cellular efflux of chemodrug. Moreover, the oxygen supply is fully exploited for upgrading the generation of reactive oxygen species (ROS) during the photodynamic process. As a result, only a single-dose treatment of the HPOCs-based chemo-PDT exhibited superior tumor suppression. The combination therapy was guided by in vivo fluorescence/photoacoustic imaging with nanoparticle tracking and oxygen monitoring.

Conclusion: This well-defined HPOC as a versatile nanosystem is expected to pave a new way for breaking multiple hypoxia-induced therapeutic resistances to achieve highly effective treatment of solid tumors.

Near-Infrared-Light-Activatable Nanomaterial-Mediated Phototheranostic Nanomedicines: An Emerging Paradigm for Cancer Treatment

Cancer is one of the most deadly diseases threatening the lives of humans. Although many treatment methods have been developed to tackle cancer, each modality of cancer treatment has its own limitations and drawbacks. The development of minimally invasive treatment modalities for cancers remains a great challenge. Near-infrared (NIR) light-activated nanomaterial-mediated phototherapies, including photothermal and photodynamic therapies, provide an alternative means for spatially and temporally controlled minimally invasive treatments of cancers. Nanomaterials can serve as nanocargoes for the delivery of chemo-drugs, diagnostic contrast reagents, and organic photosensitizers, and can be used to directly generate heat or reactive oxygen species for the treatment of tumors without the need for organic photosensitizers with NIR-light irradiation. Here, current progress in NIR-light-activated nanomaterial-mediated photothermal therapy and photodynamic therapy is summarized. Furthermore, the effects of size, shape, and surface functionalities of nanomaterials on intracellular uptake, macrophage clearance, biodistribution, cytotoxicities, and biomedical efficacies are discussed. The use of various types of nanomaterials, such as gold nanoparticles, carbon nanotubes, graphene, and many other inorganic nanostructures, in combination with diagnostic and therapeutic modalities for solid tumors, is briefly reviewed.

Leveraging Engineering of Indocyanine Green-Encapsulated Polymeric Nanocomposites for Biomedical Applications

In recent times, photo-induced therapeutics have attracted enormous interest from researchers due to such attractive properties as preferential localization, excellent tissue penetration, high therapeutic efficacy, and minimal invasiveness, among others. Numerous photosensitizers have been considered in combination with light to realize significant progress in therapeutics. Along this line, indocyanine green (ICG), a Food and Drug Administration (FDA)-approved near-infrared (NIR, >750 nm) fluorescent dye, has been utilized in various biomedical applications such as drug delivery, imaging, and diagnosis, due to its attractive physicochemical properties, high sensitivity, and better imaging view field. However, ICG still suffers from certain limitations for its utilization as a molecular imaging probe in vivo, such as concentration-dependent aggregation, poor in vitro aqueous stability and photodegradation due to various physicochemical attributes. To overcome these limitations, much research has been dedicated to engineering numerous multifunctional polymeric composites for potential biomedical applications. In this review, we aim to discuss ICG-encapsulated polymeric nanoconstructs, which are of particular interest in various biomedical applications. First, we emphasize some attractive properties of ICG (including physicochemical characteristics, optical properties, metabolic features, and other aspects) and some of its current limitations. Next, we aim to provide a comprehensive overview highlighting recent reports on various polymeric nanoparticles that carry ICG for light-induced therapeutics with a set of examples. Finally, we summarize with perspectives highlighting the significant outcome, and current challenges of these nanocomposites.

Nanotechnology for Cancer Therapy Based on Chemotherapy

Chemotherapy has been widely applied in clinics. However, the therapeutic potential of chemotherapy against cancer is seriously dissatisfactory due to the nonspecific drug distribution, multidrug resistance (MDR) and the heterogeneity of cancer. Therefore, combinational therapy based on chemotherapy mediated by nanotechnology, has been the trend in clinical research at present, which can result in a remarkably increased therapeutic efficiency with few side effects to normal tissues. Moreover, to achieve the accurate pre-diagnosis and real-time monitoring for tumor, the research of nano-theranostics, which integrates diagnosis with treatment process, is a promising field in cancer treatment. In this review, the recent studies on combinational therapy based on chemotherapy will be systematically discussed. Furthermore, as a current trend in cancer treatment, advance in theranostic nanoparticles based on chemotherapy will be exemplified briefly. Finally, the present challenges and improvement tips will be presented in combination therapy and nano-theranostics.

Near-Infrared-Light-Induced Morphology Transition of Poly(ether amine) Nanoparticles for Supersensitive Drug Release

Near-infrared (NIR)-light-controlled drug release has aroused great interest because of its advantages in spatiotemporal control. Herein, a photothermally induced morphology transition of the nanoparticles (NPs) for supersensitive drug release has been demonstrated. Doxorubicin (DOX)- and cyanine (Cy)-coloaded thermosensitive poly(ether amine) NPs (DOX&Cy@PEA81) were developed. Because of the photothermal activity of Cy upon irradiation, increase in temperature at the tumor site results, which would be used not only for photothermal therapy but also to spur the release of DOX from the NPs for tunable chemotherapy. The NIR-laser-driven DOX release was validated by a series of intracellular and in vivo experiments on animals. Meanwhile, the chemo-photothermal combinatorial therapy results in optimal cytotoxicity and tumor inhibition. This article provides a promising approach to realizing supersensitive drug release and synergistic chemo-photothermal therapy for cancer.

Photothermally Amplified Therapeutic Liposomes for Effective Combination Treatment of Cancer

Near-infrared photothermal therapy has been investigated extensively with regard to selective tumor eradication, yet its clinical translation has been limited because of the absence of FDA-approvable agents with effective phototherapeutic function and minimal systemic toxicity. In this work, we developed photothermally amplified therapeutic liposomes in an attempt to synergize chemotherapy and hyperthermia for effective cancer phototherapy. The anticancer drug cisplatin and the photothermal agent indocyanine green (ICG) were encapsulated in a thermosensitive liposomal formulation at the lipid/ICG ratio maximizing the ICG loading efficiency. These liposomes released cytotoxic cisplatin molecules selectively via ICG-mediated photothermal stimulation. In phototherapeutic studies, these liposomes amplified therapeutic effects both in vitro in cancer cells and in vivo in mouse tumor models significantly over chemotherapy or photothermal therapy alone. We believe that these photothermally amplified therapeutic liposomes composed solely of already FDA-approved components (cisplatin, ICG, and phospholipids) have enormous potential for clinical translation in treating various tumors compatible with laser irradiation.

Indocyanine green-incorporating nanoparticles for cancer theranostics

Indocyanine green (ICG) is a near-infrared dye that has been used in the clinic for retinal angiography, and defining cardiovascular and liver function for over 50 years. Recently, there has been an increasing interest in the incorporation of ICG into nanoparticles (NPs) for cancer theranostic applications. Various types of ICG-incorporated NPs have been developed and strategically functionalised to embrace multiple imaging and therapeutic techniques for cancer diagnosis and treatment. This review systematically summaries the biodistribution of various types of ICG-incorporated NPs for the first time, and discusses the principles, opportunities, limitations, and application of ICG-incorporated NPs for cancer theranostics. We believe that ICG-incorporated NPs would be a promising multifunctional theranostic platform in oncology and facilitate significant advancements in this research-active area.

Theranostic Nanoplatform: Triple-Modal Imaging-Guided Synergistic Cancer Therapy Based on Liposome-Conjugated Mesoporous Silica Nanoparticles

Mesoporous silica nanoparticles (MSNs) have long since been investigated to provide a versatile drug-delivery platform due to their multitudinous merits. Presently, gadolinium (Gd), a T1 magnetic resonance imaging (MRI) contrast agent, was doped into MSNs as a newly emerging theranostic nanocomposite, which has received much research attention. However, it is still concerned about the dispersibility and drug leakage of MSNs. Hence, in this project, we constructed an near-infrared (NIR) irradiation-triggered, triple-modal imaging-guided nanoplatform based on doxorubicin (DOX)@Gd-doped MSNs, conjugating with indocyanine green (ICG)-loaded thermosensitive liposomes (designated as DOX@GdMSNs-ICG-TSLs). In this platform, ICG could contribute to both photodynamic therapy and photothermal therapy effects; meanwhile, it could also give play to near-infrared fluorescence imaging (NIRFI) as well as photoacoustic imaging (PAI). Consequently, NIRFI and PAI from ICG combined with the MRI function of Gd, devoted to triple-modal imaging with success. At the same time, folic acid-modified thermosensitive liposomes were explored to be coated onto the surface of DOX@GdMSNs, to solve the DOX leakage as well as improve cellular uptake. Under NIR irradiation, ICG could generate heat, thus leading to the rupture of ICG-TSLs and the release of DOX. Accordingly, the multifunctional nanocomposite appeared to be a promising meritorious theranostic nanoplatform to pave a way for treating cancer.

Near-infrared light-responsive, diselenide containing core-cross-linked micelles prepared by the Diels–Alder click reaction for photocontrollable drug release application

We report a facile and efficient preparation of a NIR-triggered micelle system for a drug vehicle.

A Smart Europium-Ruthenium Complex as Anticancer Prodrug: Controllable Drug Release and Real-Time Monitoring under Different Light Excitations

A unique, dual-function, photoactivatable anticancer prodrug, RuEuL, has been tailored that features a ruthenium(II) complex linked to a cyclen-europium chelate via a π-conjugated bridge. Under irradiation at 488 nm, the dark-inactive prodrug undergoes photodissociation, releasing the DNA-damaging ruthenium species. Under evaluation-window irradiation (λ_irr = one-photon 350 nm or two-photon 700 nm), the drug delivery process can be quantitatively monitored in real-time because of the long-lived red europium emission. Linear relationships between released drug concentration and ESI-MS or luminescence responses are established. Finally, the efficiency of the new prodrug is demonstrated both in vitro RuEuL anticancer prodrug over some existing ones and open the way for decisive improvements in multipurpose prodrugs.

Tumor-associated macrophages, nanomedicine and imaging: the axis of success in the future of cancer immunotherapy

The success of any given cancer immunotherapy relies on several key factors. In particular, success hinges on the ability to stimulate the immune system in a controlled and precise fashion, select the best treatment options and appropriate therapeutic agents, and use highly effective tools to accurately and efficiently assess the outcome of the immunotherapeutic intervention. Furthermore, a deep understanding and effective utilization of tumor-associated macrophages (TAMs), nanomedicine and biomedical imaging must be harmonized to improve treatment efficacy. Additionally, a keen appreciation of the dynamic interplay that occurs between immune cells and the tumor microenvironment (TME) is also essential. New advances toward the modulation of the immune TME have led to many novel translational research approaches focusing on the targeting of TAMs, enhanced drug and nucleic acid delivery, and the development of theranostic probes and nanoparticles for clinical trials. In this review, we discuss the key cogitations that influence TME, TAM modulations and immunotherapy in solid tumors as well as the methods and resources of tracking the tumor response. The vast array of current nanomedicine technologies can be readily modified to modulate immune function, target specific cell types, deliver therapeutic payloads and be monitored using several different imaging modalities. This allows for the development of more effective treatments, which can be specifically designed for particular types of cancer or on an individual basis. Our current capacities have allowed for greater use of theranostic probes and multimodal imaging strategies that have led to better image contrast, real-time imaging capabilities leveraging targeting moieties, tracer kinetics and enabling more detailed response profiles at the cellular and molecular levels. These novel capabilities along with new discoveries in cancer biology should drive innovation for improved biomarkers for efficient and individualized cancer therapy.

Coumarin-containing thermoresponsive hyaluronic acid-based nanogels as delivery systems for anticancer chemotherapy

Multi-stimuli responsive nanogels based on biocompatible hydrophilic polymers have emerged as promising drug delivery systems to improve anticancer therapy with hydrophobic drugs, through increase of circulating-time in the bloodstream, tumor-targeting and reduction of systemic toxicity. This paper reports on the synthesis, characterization and biological perspectives of light- and thermoresponsive hyaluronic acid (HA)-based nanogels containing coumarin as the photocleavable group. Newly synthesized nanogels exhibited interesting features: formation by a temperature-triggered self-assembly process, successful incorporation of poorly water-soluble molecules, light-responsiveness as demonstrated by a significant shift in the critical aggregation temperature after light irradiation, efficient internalization by cancer cells overexpressing the CD44 receptor of HA, ability to circulate for a prolonged period of time in the bloodstream after intravenous injection in mice and considerable detection in tumor tissues. Our findings indicate that coumarin-containing HA-based nanogels may be promising delivery systems for anticancer chemotherapy.

Mitochondria-targeting near-infrared light-triggered thermosensitive liposomes for localized photothermal and photodynamic ablation of tumors combined with chemotherapy

Lonidamine, an anticancer drug that acts on mitochondria, has poor water solubility. Mitochondria are the primary source of cellular reactive oxygen species (ROS), which are necessary for photodynamic therapy. Hence, a mitochondria-targeting drug delivery system loaded with Lonidamine and a ROS-produced photosensitizer could improve the bioavailability of Lonidamine and maximize photodynamic therapeutic efficiency. Here we report, for the first time, new IR-780 and Lonidamine encapsulated mitochondria-targeting thermosensitive liposomes (IL-TTSL). DSPE-PEG2000-NH₂ was coupled with triphenylphosphine to form DSPE-PEG_2K-TPP. The liposomes (IL-TTSL) were self-assembled from DPPC, DSPC, DSPE-PEG_2K-TPP, cholesterol, IR-780 and Lonidamine. Coupled linker modified triphenylphosphine (TPP) is cationic and can selectively accumulate several hundred-fold within mitochondria. Once the liposomes are located inside mitochondria, 808 nm laser irradiation could trigger photosensitizer IR-780 to elevate the local temperature, which could be utilized in photothermal therapy and induce the release of Lonidamine from the thermosensitive liposomes. Meanwhile, IR-780 could release ROS for photodynamic therapy in mitochondria and increase photodynamic therapeutic efficiency. Our results showed that the surface modification of the liposomes with triphenylphosphine cations had good mitochondria-targeting ability. The liposomes exhibited good biocompatibility and all components of the empty liposomes were safe to be used in humans. Few reports were related to IR-780 being used in photodynamic therapy and we proved this function of IR-780. Overall, the stealth liposomes provide a promising new strategy to realize mitochondria-targeting thermosensitive chemo-, photodynamic and photothermal combination therapy with a single light source for lung cancer.

Zwitterionic Temperature/Redox-Sensitive Nanogels for Near-Infrared Light-Triggered Synergistic Thermo-Chemotherapy

Ideal anticancer nano drug delivery systems (NDDSs) need to overcome a series of physiological barriers including blood circulation, tumor accumulation, tumor penetration, internalization by cancer cells, lysosomal escape, and on-demand intracellular drug release following systemic administration. However, it remains a big challenge to construct NDDSs that can overcome all the barriers at the same time. Here, we develop zwitterionic temperature/redox-sensitive nanogels loaded with near-infrared (NIR) dye Indocyanine green (ICG) and anticancer drug doxorubicin (I/D@NG). I/D@NG exhibits enhanced photothermal effects, and NIR irradiation markedly decreases its diameter. NIR irradiation at tumor sites significantly enhances tumor accumulation, tumor penetration, and cellular uptake of I/D@NG with prolonged blood circulation time. Furthermore, I/D@NG can effectively escape from lysosomes by singlet oxygen-induced lysosomal disruption, and DOX is then sufficiently released from the nanogels to the nucleus in response to high intracellular GSH and photothermal effects. This nanoplatform for thermo-chemotherapy not only efficiently exerts synergistic cytotoxicity but also overcomes all the physiological barriers of therapeutic agent, thereby providing a substantial in vivo anticancer effect. The multiple functions of I/D@NG provide new insights into designing nanoplatforms for synergistic cancer therapy.

Magnetic Resonance Imaging-Guided Multi-Drug Chemotherapy and Photothermal Synergistic Therapy with pH and NIR-Stimulation Release

The combination of multidrug chemotherapy and photothermal therapy (PTT) enhances cancer therapeutic efficacy. Herein, we develop a simple and smart pH/NIR dual-stimulus-responsive degradable mesoporous CoFe₂O₄@PDA@ZIF-8 sandwich nanocomposite. The mesoporous CoFe₂O₄ core acts as T₂-weighted magnetic resonance (MR) imaging probe, PTT agent, and loading platform of hydrophilic doxorubicin (DOX). A polydopamine (PDA) layer is used to avoid the premature leakage of DOX before arriving at tumor site, enhance PTT efficiency, and facilitate the integration of ZIF-8 (a kind of metal-organic framework). The ZIF-8 shell serves to encapsulate hydrophobic camptothecin (CPT) and as the switch for the pH and NIR stimulation-responsive release of the two drugs. Therefore, T₂-weighted MR imaging-guided multidrug chemotherapy and PTT synergistic treatment is achieved. Two kinds of anticancer drugs, hydrophilic DOX and hydrophobic CPT, are successfully loaded in CoFe₂O₄ and ZIF-8, respectively, so no mutual interference between the two drugs exists. A unique two-stage stepwise release process is exhibited for CPT and DOX with an interval of 12 h to improve the anticancer efficacy under the acidic microenvironment of tumor tissue. NIR irradiation achieves the burst drug-release and PTT after laser stimulation, simultaneously. With this smart design, high drug concentration is achieved at the tumor site by quick release, especially for the therapeutic drugs that show nonlinear pharmacokinetics, and PTT is integrated efficiently. Furthermore, negligible biotoxicity and a remarkable synergic antitumor effect of the hybrid nanocomposites are validated by HepG2 cells and tumor-bearing mice as models. Our multidrug delivery-releasing composite improves tumor therapeutic efficiency significantly compared with a single-drug chemotherapy system. The simple multifunctional composite system can be applied as an effective platform for personal nanomedicine with diagnosis, smart drug delivery, and cancer treatment through its remarkable photothermal property and controllable multidrug release.

Cyanine based Nanoprobes for Cancer Theranostics

Cyanine dyes are greatly accredited in the development of non-invasive therapy that can "see" and "treat" tumor cells via imaging, photothermal and photodynamic treatment. However, these dyes suffer from poor pharmacokinetics inducing severe toxicity to normal cells, insufficient accumulation in tumor regions and rapid photobleaching when delivered in free forms. Nanoparticles engineered to encapsulate these compounds and delivering them into tumor regions have increased rapidly, however, so far, these nanoparticles (NPs) have not proved to be so effective to circumvent existing challenges. Newly designed multifunctional smart nanocarriers that can improve phototherapeutic properties of these dyes, co-encapsulate multiple potent therapeutic compounds, and simultaneously overcome limitations related to tumor recurrence, metastases, limited intracellular uptake, and tumor hypoxia have potential to revolutionize modern paradigm of cancer therapy. Such cyanine based multifunctional nanocarriers integrating imaging and therapy in a single platform can effectively produce better clinical outcomes in cancer treatment. This review briefly summarizes recent advancements of cyanine nanoprobes that are currently used as imaging/phototherapeutic agents in unimodal/bimodal/trimodal cancer theranostics. Finally, we conclude this review by addressing challenges of pre-existing therapeutic systems and designs adopted to overcome them with a brief insight assimilating future perspective of emerging cyanine-based NPs in cancer theranostics.

NIRF Heptamethine Cyanine Dye Nanocomplexes for Multi Modal Theranosis of Tumors

Heptamethine cyanine dyes are categorized as a class of near infrared fluorescent (NIRF) dyes which have been discovered to have tumor targeting and accumulation capability. This unique feature of NIRF dye makes it a promising candidate for imaging, targeted therapy and also as a drug delivery vehicle for various types of cancers. The favored uptake of dyes only in cancer cells is facilitated by several factors which include organic anion-transporting polypeptides, high mitochondrial membrane potential and tumor hypoxia in cancer cells. Currently nanotechnology has opened possibilities for multimodal or multifunctional strategies for cancer treatment. Including heptamethine cyanine dyes in nanoparticle based delivery systems have generally improved its theranostic ability by several fold owing to the multiple functionalities and structural features of heptamethine dyes. For this reason, nanocomplexes with NIRF heptamethine cyanine dye probe are preferred over non-targeting dyes such as indo cyanine green (ICG). This review sums up current trends and progress in NIRF heptamethine cyanine dye, including dye properties, multifunctional imaging and therapeutic applications in cancer.