Versatile Nanosystem-Based Cancer Theranostics: Design Inspiration and Predetermined Routing

Platelet-Based Nanoparticles with Stimuli-Responsive for Anti-Tumor Therapy

In addition to hemostasis and coagulation, years of studies have proved that platelets are involved in the whole process of tumor progression, including tumor invasion, intravasation, extravasation, and so on. It means that this property of platelets can be used in anti-tumor therapy. However, traditional platelet-based antitumor drugs often cause autologous platelet damage due to lack of targeting, resulting in serious side effects. Therefore, the researchers designed a variety of anti-tumor drug delivery systems based on platelets by targeting platelets or platelet membrane coating. The drug delivery systems have special response modes, which is crucial in the design of nanoparticles. These modes enhance the targeting and improve the anti-tumor effect. Here, we present a review of recent discoveries in the field of the crosstalk between platelets and tumors and the progress of platelet-based anti-tumor nanoparticles.

Therapeutic gas-releasing nanomedicines with controlled release: Advances and perspectives

Nanoparticle-based drug delivery has become one of the most popular approaches for maximising drug therapeutic potentials. With the notable improvements, a greater challenge hinges on the formulation of gasotransmitters with unique challenges that are not met in liquid and solid active ingredients. Gas molecules upon release from formulations for therapeutic purposes have not really been discussed extensively. Herein, we take a critical look at four key gasotransmitters, that is, carbon monoxide (CO), nitric oxide (NO), hydrogen sulphide (H2S) and sulphur dioxide (SO2), their possible modification into prodrugs known as gas-releasing molecules (GRMs), and their release from GRMs. Different nanosystems and their mediatory roles for efficient shuttling, targeting and release of these therapeutic gases are also reviewed extensively. This review thoroughly looks at the diverse ways in which these GRM prodrugs in delivery nanosystems are designed to respond to intrinsic and extrinsic stimuli for sustained release. In this review, we seek to provide a succinct summary for the development of therapeutic gases into potent prodrugs that can be adapted in nanomedicine for potential clinical use.

PSMA-targeted low-molecular double conjugates for diagnostics and therapy

This review presents data on dual conjugates of therapeutic and diagnostic action for targeted delivery to prostate cancer cells. The works of the last ten years on this topic were analyzed. The mail attention focuses on low-molecular-weight conjugates directed to the prostate-specific membrane antigen (PSMA); the comparison of high and low molecular weight PSMA-targeted conjugates was made. The considered conjugates were divided in the review into two main classes: diagnostic bimodal conjugates (which are containing two fragments for different types of diagnostics), theranostic conjugates (containing both therapeutic and diagnostic agents); also bimodal high molecular weight therapeutic conjugates containing two therapeutic agents are briefly discussed. The data of in vitro and in vivo studies for PSMA-targeted double conjugates available by the beginning of 2021 have been analyzed.

Nanobiomechanical behavior of Fe3O4@SiO2and Fe3O4@SiO2-NH2nanoparticles over HeLa cells interfaces

In this work, we studied the impact of magnetic nanoparticles (MNPs) interactions with HeLa cells when they are exposed to high frequency alternating magnetic field (AMF). Specifically, we measured the nanobiomechanical properties of cell interfaces by using atomic force microscopy (AFM). Magnetite (Fe₃O₄) MNPs were synthesized by coprecipitation and encapsulated with silica (SiO₂): Fe₃O₄@SiO₂and functionalized with amino groups (-NH₂): Fe₃O₄@SiO₂-NH₂, by sonochemical processing. HeLa cells were incubated with or without MNPs, and then exposed to AMF at 37 °C. A biomechanical analysis was then performed through AFM, providing the Young's modulus and stiffness of the cells. The statistical analysis (p < 0.001) showed that AMF application or MNPs interaction modified the biomechanical behavior of the cell interfaces. Interestingly, the most significant difference was found for HeLa cells incubated with Fe₃O₄@SiO₂-NH₂and exposed to AMF, showing that the local heat of these MNPs modified their elasticity and stiffness.

Polypeptide-Based Molecular Platform and Its Docetaxel/Sulfo-Cy5-Containing Conjugate for Targeted Delivery to Prostate Specific Membrane Antigen

A strategy for stereoselective synthesis of molecular platform for targeted delivery of bimodal therapeutic or theranostic agents to the prostate-specific membrane antigen (PSMA) receptor was developed. The proposed platform contains a urea-based, PSMA-targeting Glu-Urea-Lys (EuK) fragment as a vector moiety and tripeptide linker with terminal amide and azide groups for subsequent addition of two different therapeutic and diagnostic agents. The optimal method for this molecular platform synthesis includes (a) solid-phase assembly of the polypeptide linker, (b) coupling of this linker with the vector fragment, (c) attachment of 3-aminopropylazide, and (d) amide and carboxylic groups deprotection. A bimodal theranostic conjugate of the proposed platform with a cytostatic drug (docetaxel) and a fluorescent label (Sulfo-Cy5) was synthesized to demonstrate its possible sequential conjugation with different functional molecules.

Charge-conversional polyethylenimine-entrapped gold nanoparticles with 131I-labeling for enhanced dual mode SPECT/CT imaging and radiotherapy of tumors

Novel theranostic nanosystems demonstrate great potential to achieve timely diagnosis and effective therapy at the same time. However, due to the relatively low accumulation of theranostic nanosystems at the tumor site, the theranostic efficiency is limited. In this study, a novel theranostic nanosystem with a pH-responsive charge conversion property was constructed to improve the cellular uptake towards cancer cells for enhanced single photon emission computed tomography (SPECT)/computed tomography (CT) dual mode imaging and radiotherapy of tumors. In detail, polyethylenimine (PEI) was utilized as a nanoplatform to link with polyethylene glycol (PEG) monomethyl ether with one end of N-hydroxylsuccinimide (mPEG-NHS), PEG with ends of maleimide and succinimidyl valerate (MAL-PEG-SVA), alkoxyphenyl acylsulfonamide (APAS), 3-(4'-hydroxyphenyl)propionic acid-OSu (HPAO), and fluorescein isothiocyanate (FI), successively. The formed functionalized PEI was then utilized to entrap gold nanoparticles, acetylate the remaining amines of PEI and label with radioactive iodine-131 (¹³¹I) to build theranostic nanosystems. The result demonstrated that the theranostic nanosystem has a 3.8 nm Au core and showed excellent colloidal stability. On account of the charge conversion property of APAS, the APAS linked PEI entrapped gold nanoparticles could switch from neutral to positive in a slightly acidic microenvironment, which induced improved cellular uptake. Above all, after ¹³¹I labeling, the generated theranostic nanosystem could achieve enhanced SPECT/CT dual mode imaging and radiotherapy of cancer cells in vitro and a xenograft tumor model in vivo. The constructed APAS-linked PEI nanosystem has great potential to be used as a model for SPECT/CT imaging and radiotherapy of various types of cancer.

Characterization Of Blood-Brain Barrier Crossing And Tumor Homing Peptides By Molecular Dynamics Simulations

Introduction

The new frontier of tumor diagnosis and treatment relies on the development of delivery strategies capable of allowing the specific targeting of the diagnostic agents/chemotherapeutics, avoiding side effects. In the case of brain tumors, achieving this goal is made more difficult by the presence of the blood–brain barrier (BBB). Peptides have been revealed as excellent candidates for both BBB crossing and specific cancer homing. Nanoparticles (NPs), functionalized with BBB crossing and tumor homing (TH) peptides, are emerging as smart theranostic systems. However, there is still poor knowledge concerning the molecular structure and dynamical properties of these peptides, essential requirements for a suitable functionalization of the delivery systems themselves.

Methods

In this work, by means of molecular dynamics (MD) simulations, we have extensively characterized the structural and dynamical behavior of several peptides, known to be endowed of BBB crossing and TH properties.

Results

The simulations point out that, on the basis of their conformational dynamics, the peptides can be classified in two main groups: 1) peptides assuming a specific structural conformation, a feature that could be important for interacting with the molecular target but that may limit their use as functionalizing molecules and 2) highly flexible peptides whose interaction with the target may be independent of a particular structural conformation and that may represent good candidates for the functionalization of theranostic NP-based platforms.

Discussion

Such findings may be useful for the de novo designing of NP-based delivery systems.

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Engineering of Gadolinium-Decorated Graphene Oxide Nanosheets for Multimodal Bioimaging and Drug Delivery

Engineering of water-dispersible Gd3+ ions-decorated reduced graphene oxide (Gd-rGO) nanosheets (NSs) has been performed. The multifunctional capability of the sample was studied as a novel contrast agent for swept source optical coherence tomography and magnetic resonance imaging, and also as an efficient drug-delivery nanovehicle. The synthesized samples were fabricated in a chemically stable condition, and efforts have been put toward improving its biocompatibility by functionalizing with carbohydrates molecules. Gd incorporation in rGO matrix enhanced the fluorouracil (5-FU) drug loading capacity by 34%. The release of the drug was ∼92% within 72 h. Gd-rGO nanosheets showed significant contrast in comparison to optically responsive bare GO for swept source optical coherence tomography. The longitudinal relaxivity rate (r 1) of 16.85 mM-1 s-1 for Gd-rGO was recorded, which was 4 times larger than that of the commercially used clinical contrast agent Magnevist (4 mM-1 s-1) at a magnetic field strength of 1.5 T.

Peptide-modulated self-assembly as a versatile strategy for tumor supramolecular nanotheranostics

Advances in supramolecular self-assembly have promoted the development of theranostics, the combination of both therapeutic and diagnostic functions in a single nanoplatform, which is closely associated with antitumor applications and has shown promising potential in personalized medicine. Peptide-modulated self-assembly serves as a versatile strategy for tumor supramolecular nanotheranostics possessing controllability, programmability, functionality and biosafety, thus promoting the translation of nanotheranostics from bench to bedside. In this review, we will focus on the self-assembly of peptide-photosensitizers and peptide-drugs as well as multicomponent cooperative self-assembly for the fabrication of nanotheranostics that integrate diagnosis and therapeutics for antitumor applications. Emphasis will be placed on building block design, interaction strategies and the potential relationships between their structures and properties, aiming to increase understanding of the critical role of peptide-modulated self-assembly in advancing antitumor supramolecular nanotheranostics.

A review of magnet systems for targeted drug delivery

Magnetic drug targeting is a method by which magnetic drug carriers in the body are manipulated by external magnetic fields to reach the target area. This method is potentially promising in applications for treatment of diseases like cancers, nervous system diseases, sudden sensorineural hearing loss, and so on, due to the advantages in that it can improve efficacy, reduce drug dosage and side effects. Therefore, it has received extensive attention in recent years. Successful magnetic drug targeting requires a good magnet system to guide the drug carriers to the target site. Up to date there have been many efforts to design the magnet systems for targeted drug delivery. However, there are few comprehensive reviews on these systems. Here we review the progresses made in this field. We summarized the systems already developed or proposed, and categorized them into two groups: static field magnet systems and varying field magnet systems. Based on the requirements for more powerful targeting performance, the prospects and the future research directions in this field are anticipated.

Synthesis and Feasibility Evaluation of a new Trastuzumab Conjugate Integrated with Paclitaxel and 89Zr for Theranostic Application Against HER2-Expressing Breast Cancers

The preparation and in  vitro evaluation of a theranostic conjugate composed of trastuzumab, paclitaxel (PTX), and deferoxamine (DFO)-chelated 89Zr have been reported. These comounds have potential applications against HER2 receptor positive breast cancers. We conjugated DFO and PTX to trastuzumab by exploiting simple conjugation chemistry. The conjugate (DFO-trastuzumab-PTX) showed excellent radiolabeling efficiency with 89Zr and the labeled conjugate had high in vitro stability in human serum. Furthermore, DFO-trastuzumab-PTX displayed comparable cytotoxicity with PTX and 89Zr-DFO-trastuzumab-PTX exhibited HER2 receptor-mediated binding on HER2-positive MDA-MB-231 breast cancer cells. The results of our in vitro study indicate high potential of 89Zr-DFO-trastuzumab-PTX to be utilized in the theranostic application against HER2-postive breast cancers.

Iron Oxide Nanoflowers @ CuS Hybrids for Cancer Tri-Therapy: Interplay of Photothermal Therapy, Magnetic Hyperthermia and Photodynamic Therapy

Innovative synthesis routes revolutionized nanomaterial combination and design possibilities resulting in a new generation of fine-tuned nanoparticles featuring exquisite shape and constitution control. However, there is still room for improvement when it comes to the development of multi-functional nanoparticle agents merging a plurality of therapeutic functions to tackle tumors simultaneously by synergic mechanisms. Herein, we report the design of an optimized nanohybrid for cancer tri-therapy featuring a maghemite (γ-Fe2O3) nanoflower-like multicore nanoparticle conceived for efficient magnetic hyperthermia (MHT) and a spiky copper sulfide shell (IONF@CuS) with a high near-infrared (NIR) absorption coefficient suitable for photothermal (PTT) and photodynamic therapy (PDT).

Methods: Spiky-like IONF@CuS nanohybrids were obtained through a straightforward and scalable water-based template sacrificial synthesis, which allows the shell shape control by tuning polyvinylpyrrolidone (PVP) concentration. A comprehensive characterization of nanohybrid size, shape and structural properties was carried out by combining complementary TEM, SEM, HR-TEM, EELS, XRD and NTA. The all-in-one therapeutic multi-functionality was assessed on cancer cells and on tumor-bearing nude mice.

Results: Tests carried out on IONF@CuS nanohybrid aqueous dispersion demonstrated their impressive efficiency to convert light (conversion coefficient = 42 ± 6 %) and magnetic stimulation (SAR ~ 350 W g^-1) into heat as well as to induce concurrent reactive oxygen species (ROS) formation upon laser irradiation. Such capabilities were further confirmed in cellular environment by in vitro tests and at the organism level by in vivo tests in a murine tumor model. Notably, complete tumor regression was obtained for the PTT mode at low Cu concentration. Overall, these results allowed determining windows of applicability for each therapy individually or in combination.

Conclusions: Altogether, the obtained data evidence the successful synthesis of a unique tri-therapeutic nanoparticle featuring highly relevant assets for clinical translation such as reduced nanoparticle administered dose, reduced laser power exposure, reduced magnetic field frequency, and the possibility of serial heating cycles and therapy monitoring by photoacoustic (PA) and magnetic resonance imaging (MRI). Furthermore, the integration of the dual heating capability (MHT + PTT) with the PDT insult offers a unique asset to tackle tumors by multiple cytotoxic strategies in order to improve the therapeutic outcome in a broader spectrum of clinical conditions.

Nano-engineered delivery systems for cancer imaging and therapy: Recent advances, future direction and patent evaluation

Cancer is the second highest cause of death worldwide. Several therapeutic approaches, such as conventional chemotherapy, antibodies and small molecule inhibitors and nanotherapeutics have been employed in battling cancer. Amongst them, nanotheranostics is an example of successful personalized medicine bearing dual role of early diagnosis and therapy to cancer patients. In this review, we have focused on various types of theranostic polymer and metal nanoparticles for their role in cancer therapy and imaging concerning their limitation, future application such as dendritic cell cancer vaccination, gene delivery, T-cell activation and immune modulation. Also, some of the recorded patent applications and clinical trials have been illustrated. The impact of the biological microenvironment on the biodistribution and accumulation of nanoparticles have been discussed.

S. P, Bavya MC, Prasad R, Bandyopadhyaya R, Naidu VGM, Srivastava R. Niclosamide encapsulated polymeric nanocarriers for targeted cancer therapy

Localized cancer rates are on an upsurge, severely affecting mankind across the globe. Timely diagnosis and adopting appropriate treatment strategies could improve the quality of life significantly reducing the mortality and morbidity rates. Recently, nanotherapeutics has precipitously shown increased efficacy for controlling abnormal tissue growth in certain sites in the body, among which ligand functionalized nanoparticles (NP) have caught much attention for improved survival statistics via active targeting. Our focus was to repurpose the antihelminthic drug, niclosamide (NIC), which could aid in inhibiting the abnormal growth of cells restricted to a specific region. The work here presents a one-pot synthesis of niclosamide encapsulated, hyaluronic acid functionalized core–shell nanocarriers [(NIC-PLGA NP)HA] for active targeting of localized cancer. The synthesized nanocarriers were found to possess spherical morphology with mean size of 150.8 ± 9 nm and zeta potential of −24.9 ± 7.21 mV. The encapsulation efficiency was found to be 79.19 ± 0.16% with a loading efficiency of 7.19 ± 0.01%. The nanohybrids exhibited extreme cytocompatibility upon testing with MDA-MB-231 and L929 cell lines. The rate of cancer cell elimination was approximately 85% with targeted cell imaging results being highly convincing. [(NIC-PLGA NP)HA] demonstrates increased cellular uptake leading to a hike in reactive oxygen species (ROS) generation, combating tumour cells aiding in the localized treatment of cancer and associated therapy.

Localized binding of nanoparticulate formulation, actively targeting the receptors present on the cell surface.

The effect of low- and high-penetration light on localized cancer therapy

The design of a delivery system allowing targeted and controlled drug release has been considered one of the main strategies used to provide individualized cancer therapy, to improve survival statistics, and to enhance quality-of-life. External stimuli including low- and high-penetration light have been shown to have the ability to turn drug delivery on and off in a non-invasive remotely-controlled fashion. The success of this approach has been closely related to the development of a variety of drug delivery systems - from photosensitive liposomes to gold nanocages - and relies on multiple mechanisms of drug release activation. In this review, we make reference to the two extremes of the light spectrum and their potential as triggers for the delivery of antitumor drugs, along with the most recent achievements in preclinical trials and the challenges to an efficient translation of this technology to the clinical setting.

Low-intensity focused ultrasound (LIFU)-activated nanodroplets as a theranostic agent for noninvasive cancer molecular imaging and drug delivery

Theranostics is a new trend in the tumor research field, which involves the integration of diagnostic and therapeutic functions using imageable nanoparticles coupled with therapeutic drugs. Imaging-guided targeted delivery of therapeutics and diagnostics using nanocarriers hold great promise to minimize the side effects of conventional chemotherapy. Ultrasound microbubbles have been employed as theranostic agents over the last decade, which provide both real-time dynamic imaging for diagnosis and precise control for targeted tumor therapy. However, the intrinsic defects of microbubbles such as poor tissue penetration, short circulation time and instability hinder microbubble-based theranostic applications. In recent years, liquid-to-gas transitional perfluorocarbon nanoparticles have been developed as promising diagnostic and therapeutic nanoagents to solve the abovementioned problems. In this study, phase-changeable, folate-targeted perfluoropentane nanodroplets loaded with 10-hydroxycamptothecin (HCPT) and superparamagnetic Fe3O4 (denoted as FA-HCPT-Fe3O4-PFP NDs) are prepared and investigated for multimodal tumor imaging and targeted therapy. After intravenous administration into nude mice bearing SKOV3 ovarian cancer, FA-HCPT-Fe3O4-PFP NDs exhibit the ability to enhance MR and PA imaging. Furthermore, after the phase transition activated by low-intensity focused ultrasound (LIFU) sonication, FA-HCPT-Fe3O4-PFP NDs remarkably enhance US imaging at the tumor location. Meanwhile, the HCPT released from FA-HCPT-Fe3O4-PFP NDs during the liquid-to-gas transition provides a therapeutic effect on tumor cells with relatively low side effects to normal tissue. Therefore, the combination of LIFU and FA-HCPT-Fe3O4-PFPNDs presents an ideal modality for tumor-targeted theranostics.

Functional Diagnostic and Therapeutic Nanoconstructs for Efficient Probing of Circulating Tumor Cells

The circulation of tumor cells in peripheral blood is mostly recognized as a prerequisite for cancer progression or systemic invasion, and it correlates with the pivotal hallmark of malignancies known as metastasis. Multiple detection schemes for circulating tumor cells (CTCs) have emerged as the most discerning criteria for monitoring the outcome of anticancer therapy. Therefore, there has been a tremendous increase in the use of robust nanostructured platforms for observation of these mobile tumor cells through various simultaneous diagnosis and treatment regimens developed from conventional techniques. This review seeks to give detailed information about the nature of CTCs as well as techniques for exploiting specific biomarkers to help monitor cancer via detection, capturing, and analysis of unstable tumor cells. We will further discuss nanobased diagnostic interventions and novel platforms which have recently been developed from versatile nanomaterials such as polymer nanocomposites, metal organic frameworks, bioderived nanomaterials and other physically responsive particles with desirable intrinsic and external properties. Herein, we will also include in vivo nanotheranostic platforms which have received a lot of attention because of their enormous clinical potential. In all, this review sums up the general potential of key promising nanoinspired systems as well as other advanced strategies under research and those in clinical use.

Bio-Inspired Protein-Based Nanoformulations for Cancer Theranostics

Over the past decade, more interests have been aroused in engineering protein-based nanoformulations for cancer treatment. This excitement originates from the success of FDA approved Abraxane (Albumin-based paclitaxel nanoparticles) in 2005. The new generation of biocompatible endogenous protein-based nanoformulations is currently constructed through delivering cancer therapeutic and diagnostic agents simultaneously, as named potential theranostics. Protein nanoformulations are commonly incorporated with dyes, contrast agents, drug payloads or inorganic nanoclusters, serving as imaging-guided combinatorial cancer therapeutics. Employing the nature identity of proteins, the theranostics, escape the clearance by reticuloendothelial cells and have a long blood circulation time. The nanoscale sizet allows them to be penetrated deeply into tumor tissues. In addition, stimuli release and targeted molecules are incorporated to improve the delivery efficiency. The ongoing advancement of protein-based nanoformulations for cancer theranostics in recent 5 years is reviewed in this paper. Fine-designed nanoformulations based on albumin, ferritin, gelatin, and transferrin are highlighted from the literature. Finally, the current challenges are identified in translating protein-based nanoformulations from laboratory to clinical trials.

Redox-responsive dextran based theranostic nanoparticles for near-infrared/magnetic resonance imaging and magnetically targeted photodynamic therapy

Photodynamic therapy (PDT) is a site-specific treatment of cancer using much lower optical power densities with minimal nonspecific damage to normal tissues. To improve the therapeutic efficiency of PDT, we fabricated a multifunctional theranostic nanoparticle system (DSSCe6@Fe₃O₄ NPs) by loading Fe₃O₄ nanoparticles in redox-responsive chlorin e6 (Ce6)-conjugated dextran nanoparticles for near-infrared (NIR)/magnetic resonance (MR) dual-modality imaging and magnetic targeting. The obtained DSSCe6@Fe₃O₄ NPs demonstrated a uniform nanospherical morphology consisting of Fe₃O₄ clusters. The fluorescence signal of Ce6 of this theranostic system could turn "ON" from a self-quenching state in a reductive intracellular environment. T₂-Weighted MR imaging revealed a high transverse relaxivity (r₂) measured to be 194.4 S^-1 mM^-1, confirming that it was also a distinctive contrast agent in T₂-weighted MR imaging. Confocal images and flow cytometry results showed that the cellular uptake of DSSCe6@Fe₃O₄ NPs was enhanced effectively under an extra magnetic field, which resulted in promoted PDT therapeutic efficiency. In vivo MR imaging showed that DSSCe6@Fe₃O₄ NPs effectively accumulated in tumors under an extra magnetic field. These results illustrated that the DSSCe6@Fe₃O₄ NPs could be a promising theranostic system for both NIR/MR imaging-guided PDT precision therapy.

Carbon nanomaterials in oncology: an expanding horizon

Carbon nanomaterials have been attracting attention in oncology for the development of safe and effective cancer nanomedicines in increasing improved patient compliance for generally recognized as safe (GRAS) prominence. Toxicity, safety and efficacy of carbon nanomaterials are the major concerns in cancer theranostics. Various parameters such as particle size and shape or surface morphology, surface charge, composition, oxidation and nonoxidative-stress-related mechanisms are prone to toxicity of the carbon nanomaterials. Currently, few cancer-related products have been available on the market, although some are underway in preclinical and clinical phases. Thus, our main aim is to provide comprehensive details on the carbon nanomaterials in oncology from the past two decades for patient compliance and safety.

Near-infrared light-triggered theranostics for tumor-specific enhanced multimodal imaging and photothermal therapy

The major challenge in current clinic contrast agents (CAs) and chemotherapy is the poor tumor selectivity and response. Based on the self-quench property of IR820 at high concentrations, and different contrast effect ability of Gd-DOTA between inner and outer of liposome, we developed "bomb-like" light-triggered CAs (LTCAs) for enhanced CT/MRI/FI multimodal imaging, which can improve the signal-to-noise ratio of tumor tissue specifically. IR820, Iohexol and Gd-chelates were firstly encapsulated into the thermal-sensitive nanocarrier with a high concentration. This will result in protection and fluorescence quenching. Then, the release of CAs was triggered by near-infrared (NIR) light laser irradiation, which will lead to fluorescence and MRI activation and enable imaging of inflammation. In vitro and in vivo experiments demonstrated that LTCAs with 808 nm laser irradiation have shorter T1 relaxation time in MRI and stronger intensity in FI compared to those without irradiation. Additionally, due to the high photothermal conversion efficiency of IR820, the injection of LTCAs was demonstrated to completely inhibit C6 tumor growth in nude mice up to 17 days after NIR laser irradiation. The results indicate that the LTCAs can serve as a promising platform for NIR-activated multimodal imaging and photothermal therapy.

PEG-PCL-based nanomedicines: A biodegradable drug delivery system and its application

The lack of efficient therapeutic options for many severe disorders including cancer spurs demand for improved drug delivery technologies. Nanoscale drug delivery systems based on poly(ethylene glycol)-poly(ε-caprolactone) copolymers (PEG-PCL) represent a strategy to implement therapies with enhanced drug accumulation at the site of action and decreased off-target effects. In this review, we discuss state-of-the-art nanomedicines based on PEG-PCL that have been investigated in a preclinical setting. We summarize the various synthesis routes and different preparation methods used for the production of PEG-PCL nanoparticles. Additionally, we review physico-chemical properties including biodegradability, biocompatibility, and drug loading. Finally, we highlight recent therapeutic applications investigated in vitro and in vivo using advanced systems such as triggered release, multi-component therapies, theranostics, or gene delivery systems.

Single wavelength light-mediated, synergistic bimodal cancer photoablation and amplified photothermal performance by graphene/gold nanostar/photosensitizer theranostics

Light-triggered nanotheranostics opens a fascinating but challenging avenue to achieve simultaneous and highly efficient anticancer outcomes for multimodal therapeutic and diagnostic modalities. Herein, a multifunctional phototheranostics based on a photosensitizer-assembled graphene/gold nanostar hybrid (GO/AuNS-PEG) was developed for cancer synergistic photodynamic (PDT) and photothermal therapy (PTT) as well as effective photothermal imaging. The stable and biocompatible GO/AuNS-PEG composite displayed a high photothermal conversion efficiency due to the enhanced optical absorbance of both graphene and gold nanostars in the near-infrared (NIR) range. By tuning the absorption wavelength of GO/AuNS-PEG to that of Chlorin e6 (Ce6), GO/AuNS-PEG/Ce6 completely eliminated the EMT6 xenograft tumors by the tremendous synergistic anticancer efficiency of simultaneous PDT and PTT under a single NIR laser irradiation (660nm) in vivo. The underlying mechanism may be the enhanced cytoplasmic uptake and accumulation of GO/AuNS-PEG/Ce6 and the subsequent photodestruction of the lysosomal membrane and mitochondria. Moreover, GO/AuNS-PEG/Ce6 exhibited negligible side-effects on the body and other organs. These results demonstrate that the graphene/gold nanostar nanoconstruct provides a versatile and reliable integrated platform for the photo-controlled cancer theragnostic applications.

STATEMENT OF SIGNIFICANCE

This work demonstrated the application of graphene-Au Nanostars hybridized system (denoted as GO/AuNS-PEG) in single wavelength laser induced synergistic photodynamic (PDT) and photothermal therapy (PTT) and effective cancer photothermal/fluorescence multimode imaging. GO/AuNS-PEG showed excellent biocompatibility and high dual-enhanced photothermal efficiency under the near-infrared laser irradiation that was very promise for deep tumor imaging. By combining with the photosensitizer Chlorin e6, both in vitro and in vivo data confirmed the efficient photoablation of the EMT6 tumors through the synergistic PDT and PTT effect under the activation of a single wavelength laser.

Recent advances in carbon based nanosystems for cancer theranostics

This review deals with four different types of carbon allotrope based nanosystems and summarizes the results of recent studies that are likely to have applications in cancer theranostics. We discuss the applications of these nanosystems for cancer imaging, drug delivery, hyperthermia, and PDT/TA/PA.

99mTc-conjugated manganese-based mesoporous silica nanoparticles for SPECT, pH-responsive MRI and anti-cancer drug delivery

In recent decades, hybrid imaging techniques that exploit the advantages of multiple imaging technologies have aroused extensive attention due to the deficiencies of single imaging modes. Along with the development of single photon emission computed tomography-magnetic resonance imaging (SPECT-MRI), it is currently necessary to develop a series of dual probes that can combine the outstanding sensitivity of SPECT with the high spatial resolution of MRI. Herein, the commonly used technetium-99 (^99mTc) was labelled on the surface of manganese oxide-based mesoporous silica nanoparticles (MnO_x-MSNs) for use in SPECT-MRI dual-modal imaging. The radiolabelling yield was as high as 99.1 ± 0.6%, and the r₁ value of the nanoprobes was able to reach 6.60 mM^-1 s^-1 due to the pH-responsive properties of the MnO_x-MSNs. The high-performance SPECT-MRI dual-modal imaging was confirmed in vivo in tumour-bearing mice, which could also provide semi-quantitative information for tumour detection. Importantly, these nanoprobes can deliver anti-cancer drugs in cancer therapy due to their unique mesoporous structures. Thus, nanotheranostics combining dual-modal imaging with anti-cancer therapeutic properties were achieved.

Focused ultrasound induced hyperthermia accelerates and increases the uptake of anti-HER-2 antibodies in a xenograft model

Image guided drug delivery has gained significant attention during the last few years. Labelling nanoparticles or macromolecules and monitoring their fate in the body provides information that can be used to modulate their biodistribution and improve their pharmacokinetics. In this study we label antibodies and monitor their distribution in the tumours post intravenous injection. Using Focused Ultrasound (FUS, a non-invasive method of hyperthermia) we increase the tumour temperature to 42°C for a short period of time (3-5min) and we observe an increased accumulation of labelled antibody. Repetition of focused ultrasound induced hyperthermic treatment increased still further the accumulation of the antibodies in the tumour. This treatment also augmented the accumulation of other macromolecules non-specific to the tumour, such as IgG and albumin. These effects may be used to enhance the therapeutic efficiency of antibodies and/or targeted nanoparticles.

Progress in the Development of Nanotheranostic Systems

This thematic issue includes both review and research articles and is intended to provide an overview on the recent progress in the development of nanostructure-based therapeutic, diagnostic, and theranostic systems.