Cu-Fe-Se Ternary Nanosheet-Based Drug Delivery Carrier for Multimodal Imaging and Combined Chemo/Photothermal Therapy of Cancer

Assessment of CuFeSe2 ternary nanozymes for multimodal triple negative breast cancer theranostics

Triple negative breast cancer (TNBC) remains a challenge for clinical diagnosis and therapy due to its poor prognosis and high mortality rate. Hence, new methods to achieve TNBC imaging and imaging-guided TNBC therapy are urgently needed. Currently, the combination of chemotherapy with phototherapy/catalytic therapy has become a promising strategy for cancer treatment. Here, multifunctional CuFeSe2 ternary nanozymes (CuFeSe2-AMD3100-Gem nanosheets) were prepared as high-performance nanotheranostic agents for imaging-guided synergistic therapy of TNBC in vitro and in vivo. CuFeSe2-AMD3100-Gem nanosheets not only exhibited outstanding CXCR4-targeted capability and superior photothermal properties, but also produced exact chemical cytotoxicity through the loading of the chemotherapy drug Gemcitabine. Specifically, the CuFeSe2-AMD3100-Gem nanosheets simultaneously possessed peroxidase-like activities capable of converting endogenous H2O2 to hydroxyl radicals (•OH), which could be significantly enhanced under light irradiation. Furthermore, these nanosheets showed remarkable multimodal imaging ability for magnetic resonance imaging (MRI), computed tomography (CT) and infrared thermography in TNBC tumor-bearing mice (4T1 cells). More importantly, the in vitro and in vivo results verified the significant synergistic anticancer effect of the CuFeSe2-AMD3100-Gem nanosheets by combining photothermal therapy and enzyme catalytic therapy with chemotherapy. In conclusion, these advantages demonstrate the powerful potential of CuFeSe2 ternary nanozymes for imaging-guided synergistic photothermal/catalytic/chemical therapy for TNBC.

Exploring innovative strides in radiolabeled nanoparticle progress for multimodality cancer imaging and theranostic applications

Multimodal imaging unfolds as an innovative approach that synergistically employs a spectrum of imaging techniques either simultaneously or sequentially. The integration of computed tomography (CT), magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), positron emission tomography (PET), and optical imaging (OI) results in a comprehensive and complementary understanding of complex biological processes. This innovative approach combines the strengths of each method and overcoming their individual limitations. By harmoniously blending data from these modalities, it significantly improves the accuracy of cancer diagnosis and aids in treatment decision-making processes. Nanoparticles possess a high potential for facile functionalization with radioactive isotopes and a wide array of contrast agents. This strategic modification serves to augment signal amplification, significantly enhance image sensitivity, and elevate contrast indices. Such tailored nanoparticles constructs exhibit a promising avenue for advancing imaging modalities in both preclinical and clinical setting. Furthermore, nanoparticles function as a unified nanoplatform for the co-localization of imaging agents and therapeutic payloads, thereby optimizing the efficiency of cancer management strategies. Consequently, radiolabeled nanoparticles exhibit substantial potential in driving forward the realms of multimodal imaging and theranostic applications. This review discusses the potential applications of molecular imaging in cancer diagnosis, the utilization of nanotechnology-based radiolabeled materials in multimodal imaging and theranostic applications, as well as recent advancements in this field. It also highlights challenges including cytotoxicity and regulatory compliance, essential considerations for effective clinical translation of nanoradiopharmaceuticals in multimodal imaging and theranostic applications.

Photothermal therapy of copper incorporated nanomaterials for biomedicine

Studies have reported on the significance of copper incorporated nanomaterials (CINMs) in cancer theranostics and tissue regeneration. Given their unique physicochemical properties and tunable nanostructures, CINMs are used in photothermal therapy (PTT) and photothermal-derived combination therapies. They have the potential to overcome the challenges of unsatisfactory efficacy of conventional therapies in an efficient and non-invasive manner. This review summarizes the recent advances in CINMs-based PTT in biomedicine. First, the classification and structure of CINMs are introduced. CINMs-based PTT combination therapy in tumors and PTT guided by multiple imaging modalities are then reviewed. Various representative designs of CINMs-based PTT in bone, skin and other organs are presented. Furthermore, the biosafety of CINMs is discussed. Finally, this analysis delves into the current challenges that researchers face and offers an optimistic outlook on the prospects of clinical translational research in this field. This review aims at elucidating on the applications of CINMs-based PTT and derived combination therapies in biomedicine to encourage future design and clinical translation.

Nanoarchitecture-based photothermal ablation of cancer: A systematic review

Photothermal therapy (PTT) is an emerging non-invasive method used in cancer treatment. In PTT, near-infrared laser light is absorbed by a chromophore and converted into heat within the tumor tissue. PTT for cancer usually combines a variety of interactive plasmonic nanomaterials with laser irradiation. PTT enjoys PT agents with high conversion efficiency to convert light into heat to destroy malignant tissue. In this review, published studies concerned with the use of nanoparticles (NPs) in PTT were collected by a systematic and comprehensive search of PubMed, Cochrane, Embase, and Scopus databases. Gold, silver and iron NPs were the most frequent choice in PTT. The use of surface modified NPs allowed selective delivery and led to a precise controlled increase in the local temperature. The presence of NPs during PTT can increase the reactive generation of oxygen species, damage the DNA and mitochondria, leading to cancer cell death mainly via apoptosis. Many studies recently used core-shell metal NPs, and the effects of the polymer coating or ligands targeted to specific cellular receptors in order to increase PTT efficiency were often reported. The effective parameters (NP type, size, concentration, coated polymers or attached ligands, exposure conditions, cell line or type, and cell death mechanisms) were investigated individually. With the advances in chemical synthesis technology, NPs with different shapes, sizes, and coatings can be prepared with desirable properties, to achieve multimodal cancer treatment with precision and specificity.

Theranostic applications of selenium nanomedicines against lung cancer

The incidence and mortality rates of lung cancer are among the highest in the world. Traditional treatment methods include surgery, chemotherapy, and radiotherapy. Although rapid progress has been achieved in the past decade, treatment limitations remain. It is therefore imperative to identify safer and more effective therapeutic methods, and research is currently being conducted to identify more efficient and less harmful drugs. In recent years, the discovery of antitumor drugs based on the essential trace element selenium (Se) has provided good prospects for lung cancer treatments. In particular, compared to inorganic Se (Inorg-Se) and organic Se (Org-Se), Se nanomedicine (Se nanoparticles; SeNPs) shows much higher bioavailability and antioxidant activity and lower toxicity. SeNPs can also be used as a drug delivery carrier to better regulate protein and DNA biosynthesis and protein kinase C activity, thus playing a role in inhibiting cancer cell proliferation. SeNPs can also effectively activate antigen-presenting cells to stimulate cell immunity, exert regulatory effects on innate and regulatory immunity, and enhance lung cancer immunotherapy. This review summarizes the application of Se-based species and materials in lung cancer diagnosis, including fluorescence, MR, CT, photoacoustic imaging and other diagnostic methods, as well as treatments, including direct killing, radiosensitization, chemotherapeutic sensitization, photothermodynamics, and enhanced immunotherapy. In addition, the application prospects and challenges of Se-based drugs in lung cancer are examined, as well as their forecasted future clinical applications and sustainable development.

Radiolabeled nanomaterial for cancer diagnostics and therapeutics: principles and concepts

In the last three decades, radiopharmaceuticals have proven their effectiveness for cancer diagnosis and therapy. In parallel, the advances in nanotechnology have fueled a plethora of applications in biology and medicine. A convergence of these disciplines has emerged more recently with the advent of nanotechnology-aided radiopharmaceuticals. Capitalizing on the unique physical and functional properties of nanoparticles, radiolabeled nanomaterials or nano-radiopharmaceuticals have the potential to enhance imaging and therapy of human diseases. This article provides an overview of various radionuclides used in diagnostic, therapeutic, and theranostic applications, radionuclide production through different techniques, conventional radionuclide delivery systems, and advancements in the delivery systems for nanomaterials. The review also provides insights into fundamental concepts necessary to improve currently available radionuclide agents and formulate new nano-radiopharmaceuticals.

Designing Intelligent Nanomaterials to Achieve Highly Sensitive Diagnoses and Multimodality Therapy of Bladder Cancer

Bladder cancer (BC) is among the most common malignant tumors of the genitourinary system worldwide. In recent years, the rate of BC incidence has increased, and the recurrence rate is high, resulting in poor quality of life for patients. Therefore, how to develop an effective method to achieve synchronous precise diagnoses and BC therapies is a difficult problem to solve clinically. Previous reports usually focus on the role of nanomaterials as drug delivery carriers, while a summary of the functional design and application of nanomaterials is lacking. Summarizing the application of functional nanomaterials in high-sensitivity diagnosis and multimodality therapy of BC is urgently needed. This review summarizes the application of nanotechnology in BC diagnosis, including the application of nanotechnology in the sensoring of BC biomarkers and their role in monitoring BC. In addition, conventional and combination therapies strategy in potential BC therapy are analyzed. Moreover, different kinds of nanomaterials in BC multimodal therapy according to pathological features of BC are also outlined. The goal of this review is to present an overview of the application of nanomaterials in the theranostics of BC to provide guidance for the application of functional nanomaterials to precisely diagnose and treat BC.

Advances in Single-component inorganic nanostructures for photoacoustic imaging guided photothermal therapy

Phototheranostic based on photothermal therapy (PTT) and photoacoustic imaging (PAI), as one of avant-garde medical techniques, have sparked growing attention because it allows noninvasive, deeply penetrative, and highly selective and effective therapy. Among a variety of phototheranostic nanoagents, single-component inorganic nanostructures are found to be novel and attractive PAI and PTT combined nanotheranostic agents and received tremendous attention, which not only exhibit structural controllability, high tunability in physiochemical properties, size-dependent optical properties, high reproducibility, simple composition, easy functionalization, and simple synthesis process, but also can be endowed with multiple therapeutic and imaging functions, realizing the superior therapy result along with bringing less foreign materials into body, reducing systemic side effects and improving the bioavailability. In this review, according to their synthetic components, conventional single-component inorganic nanostructures are divided into metallic nanostructures, metal dichalcogenides, metal oxides, carbon based nanostructures, upconversion nanoparticles (UCNPs), metal organic frameworks (MOFs), MXenes, graphdiyne and other nanostructures. On the basis of this category, their detailed applications in PAI guide PTT of tumor treatment are systematically reviewed, including synthesis strategies, corresponding performances, and cancer diagnosis and therapeutic efficacy. Before these, the factors to influence on photothermal effect and the principle of in vivo PAI are briefly presented. Finally, we also comprehensively and thoroughly discussed the limitation, potential barriers, future perspectives for research and clinical translation of this single-component inorganic nanoagent in biomedical therapeutics.

(Nano)platforms in bladder cancer therapy: Challenges and opportunities

Urological cancers are among the most common malignancies around the world. In particular, bladder cancer severely threatens human health due to its aggressive and heterogeneous nature. Various therapeutic modalities have been considered for the treatment of bladder cancer although its prognosis remains unfavorable. It is perceived that treatment of bladder cancer depends on an interdisciplinary approach combining biology and engineering. The nanotechnological approaches have been introduced in the treatment of various cancers, especially bladder cancer. The current review aims to emphasize and highlight possible applications of nanomedicine in eradication of bladder tumor. Nanoparticles can improve efficacy of drugs in bladder cancer therapy through elevating their bioavailability. The potential of genetic tools such as siRNA and miRNA in gene expression regulation can be boosted using nanostructures by facilitating their internalization and accumulation at tumor sites and cells. Nanoparticles can provide photodynamic and photothermal therapy for ROS overgeneration and hyperthermia, respectively, in the suppression of bladder cancer. Furthermore, remodeling of tumor microenvironment and infiltration of immune cells for the purpose of immunotherapy are achieved through cargo-loaded nanocarriers. Nanocarriers are mainly internalized in bladder tumor cells by endocytosis, and proper design of smart nanoparticles such as pH-, redox-, and light-responsive nanocarriers is of importance for targeted tumor therapy. Bladder cancer biomarkers can be detected using nanoparticles for timely diagnosis of patients. Based on their accumulation at the tumor site, they can be employed for tumor imaging. The clinical translation and challenges are also covered in current review.

Nanotechnology meets glioblastoma multiforme: Emerging therapeutic strategies

Glioblastoma multiforme (GBM) represents the most common and fatal form of primary invasive brain tumors as it affects a great number of patients each year and has a median overall survival of approximately 14.6 months after diagnosis. Despite intensive treatment, almost all patients with GBM experience recurrence, and their 5-year survival rate is approximately 5%. At present, the main clinical treatment strategy includes surgical resection, radiotherapy, and chemotherapy. However, tumor heterogeneity, blood-brain barrier, glioma stem cells, and DNA damage repair mechanisms hinder efficient GBM treatment. The emergence of nanometer-scale diagnostic and therapeutic approaches in cancer medicine due to the establishment of nanotechnology provides novel and promising tools that will allow us to overcome these difficulties. This review summarizes the application and recent progress in nanotechnology-based monotherapies (e.g., chemotherapy) and combination cancer treatment strategies (chemotherapy-based combined cancer therapy) for GBM and describes the synergistic enhancement between these combination therapies as well as the current standard therapy for brain cancer and its deficiencies. These combination therapies that can reduce individual drug-related toxicities and significantly enhance therapeutic efficiency have recently undergone rapid development. The mechanisms underlying these different nanotechnology-based therapies as well as the application of nanotechnology in GBM (e.g., in photodynamic therapy and chemodynamic therapy) have been systematically summarized here in an attempt to review recent developments and to identify promising directions for future research. This review provides novel and clinically significant insights and directions for the treatment of GBM, which is of great clinical importance. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Improve the cytotoxic effects of megavoltage radiation treatment by Fe3O4@Cus–PEG nanoparticles as a novel radiosensitizer in colorectal cancer cells

Background

To enhance the performance of radiotherapy, emerging nanoparticles that can professionally enhance X-ray irradiation to destruct cancer cells are extremely necessary. Here, we examined the potential of PEG-coated magnetite copper sulfide hetero-nanoparticles (Fe3O4@Cus–PEG) as a radiosensitizer agent.

Methods

Fe3O4@Cus–PEG nanoparticles were synthesized and characterized. The toxicity of nanoparticles on HT-29 colorectal cancer cells was assessed by the MTT assay. The radio-sensitizing effects of Fe3O4@Cus–PEG nanoparticles on HT-29 cancer cells were investigated by the MTT and colony formation assays. Moreover, the underlying mechanisms for Fe3O4@Cus–PEG nanoparticles to improve the radiation sensitivity of cells were evaluated.

Results

The results demonstrated that nanoparticles enhanced the effects of X-ray irradiation in a dose-dependent manner. The effects of combined treatments (nanoparticles and X-ray radiation) were strongly synergistic. The sensitizing enhancement ratio (SER) of nanoparticles was 2.02. Our in vitro assays demonstrated that the nitric oxide production, the intracellular hydrogen peroxide concentration, and the expression level of Bax and Caspase-3 genes significantly increased in the cells treated with the combination of nanoparticles and radiation. Whereas, the Glutathione peroxidase enzyme activity and the expression level of the Bcl-2 gene in the combined treatment significantly decreased compared to the radiation alone.

Conclusions

Our study suggests that Fe3O4@Cus–PEG nanoparticles are the promising nano radio-sensitizing agents for the treatment of cancer cells to enhance the efficacy of radiation therapy through increasing the reactive oxygen species generation, nitric oxide production, and inducing apoptosis.

Graphical Abstract

Drug-Loaded Acoustic Nanodroplet for Dual-Imaging Guided Highly Efficient Chemotherapy Against Nasopharyngeal Carcinoma

Background

Chemotherapy is an important approach to treating nasopharyngeal carcinoma (NPC). Unfortunately, the lack of selectivity, insufficient tumor accumulation, uneven tumor distribution and severe systemic toxicity lead to the unsatisfactory performance of these drugs. While a more precise drug delivery, on-demand drug release, and deep diffusion of drugs (homogeneous distribution of drugs in the tumor) could improve the application, they remain challenging. Chemotherapeutic drug-loaded acoustic nanodroplet with dual-imaging capacity is expected to solve these problems.

Methods

Folate (Fa)-modified and doxorubicin (Dox)-loaded acoustic poly (lactic-co-glycolic acid) (PLGA), low intensity focused ultrasound (LIFU)-responsive perfluoropentane (PFP) and Fe₃O₄ nanoparticles (designated as Fa-Fe@P-PFP-Dox) were integrated by a double-emulsion method. After the synthesis, the LIFU-triggered acoustic droplet vaporization (ADV) effect, LIFU-triggered drug release, cell targeting capability, in vitro cell-killing effects, biodistribution, PA/MR dual imaging (PA: photoacoustic; MR: magnetic resonance), LIFU-augmented Dox distribution in tumors and chemotherapeutic efficacy of Fa-Fe@P-PFP-Dox were investigated.

Results

The distribution of these drug-loaded nanodroplets was clearly monitored via PA/MR dual imaging. Upon LIFU irradiation, PFP within the Fa-Fe@P-PFP-Dox nanodroplets underwent ADV, which led to the release of Dox and promoted the deep penetration of Dox in tumor tissue, eventually achieving highly efficient chemotherapy against NPC. As a result, LIFU-triggered chemotherapy exerted a highly efficient therapeutic effect with a tumor inhibition rate of 74.24 ± 7.95%.

Conclusion

Fa-modified and drug-loaded acoustic nanodroplets have been successfully constructed for dual-imaging guided highly efficient chemotherapy against NPC. This novel tumor drug delivery method is expected to provide an efficient, visualized, and precise personalized treatment method for NPC patients with minimal side effects.

Emerging Roles of Green-Synthesized Chalcogen and Chalcogenide Nanoparticles in Cancer Theranostics

The last few decades have seen an overwhelming increase in the amount of research carried out on the use of inorganic nanoparticles. More fascinating is the tremendous progress made in the use of chalcogen and chalcogenide nanoparticles in cancer theranostics. These nanomaterials, which were initially synthesized through chemical methods, have now been efficiently produced using different plant materials. The paradigm shift towards the biogenic route of nanoparticle synthesis stems from its superior advantages of biosafety, eco-friendliness, and simplicity, among others. Despite a large number of reviews available on inorganic nanoparticle synthesis through green chemistry, there is currently a dearth of information on the green synthesis of chalcogens and chalcogenides for cancer research. Nanoformulations involving chalcogens such as sulfur, selenium, and tellurium and their respective chalcogenides have recently emerged as promising tools in cancer therapeutics and diagnosis. Similar to other inorganic nanoparticles, chalcogens and chalcogenides have been synthesized using plant extracts and their purified biomolecules. In this review, we provide an up-to-date discussion of the recent progress that has been made in the plant-mediated synthesis of chalcogens and chalcogenides with a special focus on their application in cancer theranostics.

Biodegradation Mn-CoS@carbon di-shell nanoheterostructure with enhanced nanozyme-mediated phototherapy

The efficacy of phototherapy is dependent on intracellular O₂ concentration and NIR harvest. Here, a simple nanoplatform with nanoenzyme mediated phototherapy enhances anticancer capacity. Mn-CoS@carbon (CMS/C) di-shell hollow nanospheres (50 nm) are synthesized successfully through two-step consecutive Kirkendall process. The nanoheterostructure reveals the higher near-infrared (NIR) light absorption and photothermal conversion rate of 66.3% than pure CoS (45.5%), owing to the decreased band gap and multi-reflection of incident light in the hollow structure. And CMS/C reveals the reactive oxygen species (ROS) production and nanoenzyme activities (mimic peroxidase and catalase) that are 6 and 2 times than those of pure CoS. Furthermore, the nanoenzyme exhibits NIR-enhanced abilities to produce more OH and O₂ facilitating anticancer. In addition, it also depletes glutathione (mimicking glutathione oxidase), to disturb intracellular redox-homeostasis, boosting the increase of oxidative stress. With grafting bovine serum albumin (BSA) and drug loading, CMS/C@BSA-Dox integrated multi-therapy make the great anticancer effect in vitro and vivo. After that, the nanocomposite could be biodegraded and eliminated via urinary and feces within 14 days. Based on this work, the efficient charge-separation can be designed to reveal high performance nanoenzymes as well as photosensitizers for anticancer.

Fe(III)-Doped Polyaminopyrrole Nanoparticle for Imaging-Guided Photothermal Therapy of Bladder Cancer

Clinically, the surgical treatment of bladder cancer often faces the problem of tumor recurrence, and the surgical treatment combined with postoperative chemotherapy to inhibit tumor recurrence also faces high toxicity and side effects. Therefore, the need for innovative bladder cancer treatments is urgent. For the past few years, with the development of nano science and technology, imaging-guided therapy using nanomaterials with both imaging and therapy functions has shown great advantages and can not only identify the locations of the tumors but also exhibit biodistributions of nanomaterials in the tumors, significantly improving the accuracy and efficacy of treatment. In this work, we synthesized Fe(III)-doped polyaminopyrrole nanoparticles (FePPy-NH₂ NPs). With low cytotoxicity and a blood circulation half-life of 7.59 h, high levels of FePPy-NH₂ NPs accumulated in bladder tumors, with an accumulation rate of up to 5.07%ID/g. The coordination of Fe(III) and the amino group in the structure can be used for magnetic resonance imaging (MRI), whereas absorption in the near-infrared region can be applied to photoacoustic imaging (PAI) and photothermal therapy (PTT). MRI and PAI accurately identified the location of the tumor, and based on the imaging data, laser irradiation was employed accurately. With a high photothermal conversion efficiency of 44.3%, the bladder tumor was completely resected without recurrence. Hematological analysis and histopathological analysis jointly confirmed the high level of safety of the experiment.

Chiral Cu2-xSe Nanoparticles for Enhanced Synergistic Cancer Chemodynamic/Photothermal Therapy in the Second Near-Infrared Biowindow

Chiral nanomaterials have great potential in improving the clinical therapeutic effect due to the unique chiral selectivity of biosystems. However, such a promising therapeutic strategy has so far received little attention in cancer treatment. Here, we report a first chiral Fenton catalyst, d-/l-penicillamine-modified Cu_2-xSe nanoparticles (d-/l-NPs), for enhanced synergistic cancer chemodynamic therapy (CDT) and photothermal therapy (PTT) under the second near-infrared (NIR-II) light irradiation. The chiral effect study of chiral Cu_2-xSe NPs on cancer cells shows that d-NPs exhibit stronger CDT-induced cytotoxicity than l -NPs due to the stronger internalization ability. Moreover, the hydroxyl radicals (^•OH) produced in d-NP-treated cancer cells via the CDT effect can be further improved by NIR-II light irradiation, thereby increasing the apoptosis of cancer cells. In vivo experiments show that, compared with l-NPs, d-NPs exhibit a stronger photothermal effect on the tumor site under NIR-II light irradiation and could completely eliminate the tumor under the synergistic effect of CDT and PTT. This work shows that the chirality of the surface ligand of the nanomaterials could significantly affect their cancer curative effect, which opens up a new way for the development of anticancer nanomedicine.

Integration of advanced methods and models to study drug absorption and related processes: An UNGAP perspective

This collection of contributions from the European Network on Understanding Gastrointestinal Absorption-related Processes (UNGAP) community assembly aims to provide information on some of the current and newer methods employed to study the behaviour of medicines. It is the product of interactions in the immediate pre-Covid period when UNGAP members were able to meet and set up workshops and to discuss progress across the disciplines. UNGAP activities are divided into work packages that cover special treatment populations, absorption processes in different regions of the gut, the development of advanced formulations and the integration of food and pharmaceutical scientists in the food-drug interface. This involves both new and established technical approaches in which we have attempted to define best practice and highlight areas where further research is needed. Over the last months we have been able to reflect on some of the key innovative approaches which we were tasked with mapping, including theoretical, in silico, in vitro, in vivo and ex vivo, preclinical and clinical approaches. This is the product of some of us in a snapshot of where UNGAP has travelled and what aspects of innovative technologies are important. It is not a comprehensive review of all methods used in research to study drug dissolution and absorption, but provides an ample panorama of current and advanced methods generally and potentially useful in this area. This collection starts from a consideration of advances in a priori approaches: an understanding of the molecular properties of the compound to predict biological characteristics relevant to absorption. The next four sections discuss a major activity in the UNGAP initiative, the pursuit of more representative conditions to study lumenal dissolution of drug formulations developed independently by academic teams. They are important because they illustrate examples of in vitro simulation systems that have begun to provide a useful understanding of formulation behaviour in the upper GI tract for industry. The Leuven team highlights the importance of the physiology of the digestive tract, as they describe the relevance of gastric and intestinal fluids on the behaviour of drugs along the tract. This provides the introduction to microdosing as an early tool to study drug disposition. Microdosing in oncology is starting to use gamma-emitting tracers, which provides a link through SPECT to the next section on nuclear medicine. The last two papers link the modelling approaches used by the pharmaceutical industry, in silico to Pop-PK linking to Darwich and Aarons, who provide discussion on pharmacometric modelling, completing the loop of molecule to man.

Synthesis of Monodisperse ZIF-67@CuSe@PVP Nanoparticles for pH-Responsive Drug Release and Photothermal Therapy

In recent years, the combination treatment of chemotherapy and photothermal therapy (PTT) has emerged as an efficient approach to improve anticancer activity. Here, we combine zeolitic imidazolate framework-67 (ZIF-67) and CuSe to build a multifunctional therapeutic platform (ZIF-67@CuSe@PVP) with an efficient chemo-photothermal therapy for cancer treatment. ZIF-67@CuSe@PVP nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis, Fourier transform infrared (FT-IR), and nitrogen adsorption-desorption isotherms. These nanoparticles exhibited excellent pH-responsive doxorubicin hydrochloride (DOX) releases due to the decomposition of ZIF-67 and excellent photothermal conversion efficiency (36%) without apparent deterioration during three cycles. In vivo biodistribution evaluation revealed the passive tumor-targeting ability of ZIF-67@CuSe@PVP@DOX via the enhanced permeability and retention (EPR) effect. Both in vitro and in vivo data demonstrated excellent anticancer efficacy of ZIF-67@CuSe@PVP in tumor-bearing mice. This multifunctional therapeutic platform could have certain clinical application potential.

Two-dimensional biomaterials: material science, biological effect and biomedical engineering applications

To date, nanotechnology has increasingly been identified as a promising and efficient means to address a number of challenges associated with public health. In the past decade, two-dimensional (2D) biomaterials, as a unique nanoplatform with planar topology, have attracted explosive interest in various fields such as biomedicine due to their unique morphology, physicochemical properties and biological effect. Motivated by the progress of graphene in biomedicine, dozens of types of ultrathin 2D biomaterials have found versatile bio-applications, including biosensing, biomedical imaging, delivery of therapeutic agents, cancer theranostics, tissue engineering, as well as others. The effective utilization of 2D biomaterials stems from the in-depth knowledge of structure-property-bioactivity-biosafety-application-performance relationships. A comprehensive summary of 2D biomaterials for biomedicine is still lacking. In this comprehensive review, we aim to concentrate on the state-of-the-art 2D biomaterials with a particular focus on their versatile biomedical applications. In particular, we discuss the design, fabrication and functionalization of 2D biomaterials used for diverse biomedical applications based on the up-to-date progress. Furthermore, the interactions between 2D biomaterials and biological systems on the spatial-temporal scale are highlighted, which will deepen the understanding of the underlying action mechanism of 2D biomaterials aiding their design with improved functionalities. Finally, taking the bench-to-bedside as a focus, we conclude this review by proposing the current crucial issues/challenges and presenting the future development directions to advance the clinical translation of these emerging 2D biomaterials.

Folic Acid-Conjugated CuFeSe2 Nanoparticles for Targeted T2-Weighted Magnetic Resonance Imaging and Computed Tomography of Tumors In Vivo

Background

Development of new long-circulating contrast agents for computed tomography (CT) and magnetic resonance imaging (MRI) of different biological systems still remains a great challenge. Here, we report the synthesis of folic acid (FA)-targeted CuFeSe₂ nano-contrast agent for CT and MRI imaging in vitro and in vivo.

Methods and Results

In our study, CuFeSe₂ was fabricated through a facile and green aqueous reaction and then further aminated through silanization. The amine-functionalized CuFeSe₂-NH₂ nanoparticles enable the covalent conjugation of folate-conjugated polyethylene glycol (FA-PEG-COOH) as a targeting ligand onto their surface, which could improve the dispersion and endue the targetability of nanoparticles, respectively. The formed multifunctional CuFeSe₂-PEG-FA nanoparticles were characterized via different techniques, which exhibited outstanding dispersion, good biocompatibility and excellent FA-targeted capability. Meanwhile, the nanoparticles were quite safe in the given concentration range as confirmed by in vitro and in vivo toxicity assay. Importantly, CuFeSe₂-PEG-FA nanoparticles were successfully applied in CT/MRI dual-modality imaging in vitro and in vivo, which showed a better imaging performance and targeted capability.

Conclusion

Therefore, the constructed CuFeSe₂-PEG-FA nanoparticles have a great potential as an efficient contrast agent for dual-modality imaging of different biological systems.

Stand-Alone CuFeSe2 (Eskebornite) Nanosheets for Photothermal Cancer Therapy

Two-dimensional CuFeSe2 nanosheets have been successfully obtained via solution-phase synthesis using a sacrificial template method. The high purity was confirmed by X-ray diffraction and the two-dimensional morphology was validated by transmission electron microscopy. The intense absorption in the 400-1400 nm region has been the basis for the CuFeSe2 nanosheets' photothermal capabilities testing. The colloidal CuFeSe2 (CFS) nanosheets capped with S2- short ligands (CFS-S) exhibit excellent biocompatibility in cell culture studies and strong photothermal effects upon 808 nm laser irradiation. The nanosheets were further loaded with the cancer drug doxorubicin and exposed to laser irradiation, which accelerated the release of doxorubicin, achieving synergy in the therapeutic effect.

Ultrathin Transition Metal Chalcogenide Nanosheets Synthesized via Topotactic Transformation for Effective Cancer Theranostics

Ultrathin transition metal chalcogenide (TMC) nanosheets with ultrahigh photothermal conversion efficiency (η) and excellent stability are strongly desired in the application of photothermal therapy (PTT). However, the current synthetic methods of ultrathin TMC nanosheets have issues in obtaining uniform morphology, good dispersion, and satisfactory PTT behavior. Herein, ultrathin nanosheets of CoFe-selenide (CFS) with a finely controlled structure were prepared via a topological structural transformation process from an ultrathin CoFe-layered double hydroxide (LDH) precursor, followed by surface modification with poly(ethylene glycol) (PEG). The as-prepared CFS-PEG nanosheets inherit the ultrathin morphology of CoFe-LDH and exhibit an outstanding photothermal performance with a η of 74.5%, which is the first rank level of reported two-dimensional (2D) TMC nanosheet materials. The CFS-PEG nanosheets possess a satisfactory photoacoustic (PA) imaging capability with an ultralow detection limit (5 ppm) and simultaneously superior T₂ magnetic resonance imaging (MRI) performance with a large transverse MR relaxivity value (r₂) of 347.7 mM^-1 s^-1. Moreover, in vitro and in vivo assays verify superior anticancer activity with a dramatic photoinduced cancer cell apoptosis and tumor ablation. Therefore, a successful paradigm is provided for rational design and preparation of ultrathin TMC nanosheets in this work, holding enormous potential in cancer theranostics.

Radiolabeling strategies and pharmacokinetic studies for metal based nanotheranostics

Radiolabeled metal-based nanoparticles (MNPs) have drawn considerable attention in the fields of nuclear medicine and molecular imaging, drug delivery, and radiation therapy, given the fact that they can be potentially used as diagnostic imaging and/or therapeutic agents, or even as theranostic combinations. Here, we present a systematic review on recent advances in the design and synthesis of MNPs with major focuses on their radiolabeling strategies and the determinants of their in vivo pharmacokinetics, and together how their intended applications would be impacted. For clarification, we categorize all reported radiolabeling strategies for MNPs into indirect and direct approaches. While indirect labeling simply refers to the use of bifunctional chelators or prosthetic groups conjugated to MNPs for post-synthesis labeling with radionuclides, we found that many practical direct labeling methodologies have been developed to incorporate radionuclides into the MNP core without using extra reagents, including chemisorption, radiochemical doping, hadronic bombardment, encapsulation, and isotope or cation exchange. From the perspective of practical use, a few relevant examples are presented and discussed in terms of their pros and cons. We further reviewed the determinants of in vivo pharmacokinetic parameters of MNPs, including factors influencing their in vivo absorption, distribution, metabolism, and elimination, and discussed the challenges and opportunities in the development of radiolabeled MNPs for in vivo biomedical applications. Taken together, we believe the cumulative advancement summarized in this review would provide a general guidance in the field for design and synthesis of radiolabeled MNPs towards practical realization of their much desired theranostic capabilities. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > Diagnostic Nanodevices Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Overcoming Radioresistance in Tumor Therapy by Alleviating Hypoxia and Using the HIF-1 Inhibitor

Radiotherapy has been extensively used to treat cancer patients because it can effectively damage most solid tumors without penetration limits. A hypoxic microenvironment in solid tumors leads to severe radioresistance and expression of hypoxic inducible factor-1 (HIF-1), which results in poor efficacy of radiotherapy alone. Herein, we report the excellent efficacy of radiotherapy achieved using a new type of yolk-shell Cu_2-xSe@PtSe (CSP) nanosensitizer functionalized with the HIF-1α inhibitor acriflavine (ACF). We prepare the CSP nanosensitizer through the interfacial redox reactions between chloroplatinic acid and Cu_2-xSe nanoparticles (CS) and then functionalize the nanosensitizer with ACF through their electrostatic interactions. We show that the synthesized CSP nanosensitizer can arrest the cell cycle (i.e., at the gap 2/mitosis (G₂/M) phases) of tumor cells to enhance their sensitivity to X-rays and decompose endogenous H₂O₂ into O₂ to reduce hypoxia and increase the production of reactive oxygen species, which leads to severe damage to DNA double strands and apoptosis of tumor cells. We also show that the ACF on the surface of CSP nanoparticles can effectively reduce the expression of HIF-1α. All these effects lead to a low vascular endothelial growth factor, low density of microvessels in tumor, decreased cell proliferation, and increased cell apoptosis, which synergistically and drastically enhance the efficacy of radiotherapy. This work provides insights and guidance for developing novel nanosensitizers to enhance the efficacy of radiotherapy.

A Chelate-Free Nano-Platform for Incorporation of Diagnostic and Therapeutic Isotopes

PURPOSE

Using our chelate-free, heat-induced radiolabeling (HIR) method, we show that a wide range of metals, including those with radioactive isotopologues used for diagnostic imaging and radionuclide therapy, bind to the Feraheme (FH) nanoparticle (NP), a drug approved for the treatment of iron anemia.

MATERIAL AND METHODS

FH NPs were heated (120°C) with nonradioactive metals, the resulting metal-FH NPs were characterized by inductively coupled plasma mass spectrometry (ICP-MS), dynamic light scattering (DLS), and r1 and r2 relaxivities obtained by nuclear magnetic relaxation spectrometry (NMRS). In addition, the HIR method was performed with [90Y]Y3+, [177Lu]Lu3+, and [64Cu]Cu2+, the latter with an HIR technique optimized for this isotope. Optimization included modifying reaction time, temperature, and vortex technique. Radiochemical yield (RCY) and purity (RCP) were measured using size exclusion chromatography (SEC) and thin-layer chromatography (TLC).

RESULTS

With ICP-MS, metals incorporated into FH at high efficiency were bismuth, indium, yttrium, lutetium, samarium, terbium and europium (>75% @ 120 oC). Incorporation occurred with a small (less than 20%) but statistically significant increases in size and the r2 relaxivity. An improved HIR technique (faster heating rate and improved vortexing) was developed specifically for copper and used with the HIR technique and [64Cu]Cu2+. Using SEC and TLC analyses with [90Y]Y3+, [177Lu]Lu3+ and [64Cu]Cu2+, RCYs were greater than 85% and RCPs were greater than 95% in all cases.

CONCLUSION

The chelate-free HIR technique for binding metals to FH NPs has been extended to a range of metals with radioisotopes used in therapeutic and diagnostic applications. Cations with f-orbital electrons, more empty d-orbitals, larger radii, and higher positive charges achieved higher values of RCY and RCP in the HIR reaction. The ability to use a simple heating step to bind a wide range of metals to the FH NP, a widely available approved drug, may allow this NP to become a platform for obtaining radiolabeled nanoparticles in many settings.

Radiolabeling nanomaterials for multimodality imaging: New insights into nuclear medicine and cancer diagnosis

Nuclear medicine imaging has been developed as a powerful diagnostic approach for cancers by detecting gamma rays directly or indirectly from radionuclides to construct images with beneficial characteristics of high sensitivity, infinite penetration depth and quantitative capability. Current nuclear medicine imaging modalities mainly include single-photon emission computed tomography (SPECT) and positron emission tomography (PET) that require administration of radioactive tracers. In recent years, a vast number of radioactive tracers have been designed and constructed to improve nuclear medicine imaging performance toward early and accurate diagnosis of cancers. This review will discuss recent progress of nuclear medicine imaging tracers and associated biomedical imaging applications. Radiolabeling nanomaterials for rational development of tracers will be comprehensively reviewed with highlights on radiolabeling approaches (surface coupling, inner incorporation and interface engineering), providing profound understanding on radiolabeling chemistry and the associated imaging functionalities. The applications of radiolabeled nanomaterials in nuclear medicine imaging-related multimodality imaging will also be summarized with typical paradigms described. Finally, key challenges and new directions for future research will be discussed to guide further advancement and practical use of radiolabeled nanomaterials for imaging of cancers.

Radiosensitive core/satellite ternary heteronanostructure for multimodal imaging-guided synergistic cancer radiotherapy

Developing safe, effective and targeting radiosensitizers with clear action mechanisms to achieve synergistic localized cancer treatment is an important strategy for radiotherapy. Herein, we design and synthesize a ternary heteronanostructure radiosensitizer (SeAuFe-EpC) with core/satellite morphology by a simple method to realize multimodal imaging-guided cancer radiotherapy. The mechanistic studies reveal that Se incorporation could drastically improve the electrical conductivity and lower the energy barrier between the three components, resulting in more electrons transfer between Se-Au interface and migration over the heterogeneous junction of Au-Fe₃O₄ NPs interface. This synergistic interaction enhanced the energy transfer and facilitated more excited excitons generated by SeAuFe-EpC NPs, thus promoting the transformation of ³O₂ to ¹O₂via resonance energy transfer, finally resulting in irreversible cancer cell apoptosis. Additionally, based on the X-ray attenuation ability and high NIR absorption of AuNPs and the superparamagnetism of Fe₃O₄, in vivo computer tomography, photoacoustic and magnetic resonance tri-modal imaging have been employed to visualize the tracking and targeting ability of the NPs. As expected, the NPs specifically accumulated in orthotopic breast tumor area and achieved synergistic anticancer efficacy, but showed no toxic side effects on main organs. Collectively, this study sheds light on the potential roles of core/satellite heteronanostructure in imaging-guided cancer radiotherapy.

Boosting often overlooked long wavelength emissions of rare-earth nanoparticles for NIR-II fluorescence imaging of orthotopic glioblastoma

Rare-earth nanoparticles (RE NPs) with narrow long wavelength emissions have been recently investigated for their potential application for fluorescence imaging in the second near-infrared window (NIR-II). Previously these RE NPs have a very limited application in the diagnosis and treatment of deep-seated tumors such as brain tumors, due to their weak fluorescence in the range of 1300-1700 nm. Herein, we report a significant enhancement of more than 10 times regular emission of NaNdF₄ nanoparticles at 1340 nm wavelength by coating them with an inert layer of NaLuF₄, followed by sensitizing with a near-infrared dye (IR-808). We deliver these highly bright nanoparticles into the brain by using focused ultrasound to temporarily open the blood-brain barrier (BBB), and then detect the orthotopic glioblastoma by fluorescence imaging at 1340 nm. The images obtained from long wavelength fluorescence (i.e. 1340 nm) exhibited better resolution and contrast compared to the short wavelength fluorescence (i.e. 1060 nm). Our study not only provides insights for enhancing often overlooked emissions of rare-earth nanoparticles for NIR-II fluorescence imaging of deep-seated tumors, but also demonstrates great potential of focused ultrasound based technology in delivering nanotheranostic agents.

Cholesterol-Modified Black Phosphorus Nanospheres for the First NIR-II Fluorescence Bioimaging

Black phosphorus (BP) nanostructures with unique layer-dependent properties have been extensively applied in the fields of electronic devices, energy conversion and storage, and nanomedicine. As a narrow band gap semiconductor, they are expected to show strong second near-infrared (NIR-II) fluorescence. However, there is no report on the NIR-II fluorescence of free-standing BP nanostructures, which have great potential in the NIR-II fluorescence bioimaging because of their excellent biocompatibility and biodegradability. Here, for the first time, we report that the BP nanoparticles modified with cholesterol exhibit strong NIR-II fluorescence and can be encapsulated with the PEGylated lipid to form BP@lipid-PEG nanospheres for in vitro and in vivo NIR-II imaging. The resultant BP@lipid-PEG nanospheres exhibit broad emissions from 900 to 1650 nm under excitation by an 808 nm laser and have 8% quantum yield of that of standard dye IR-26. We also show that the NIR-II fluorescence image acquired with emission beyond 1400 nm has the sharpest contrast and can be used to in situ measure the diameter of blood vessels. In addition to NIR-II fluorescence imaging, we also show the potential of BP@lipid-PEG nanospheres in photoacoustic (PA) imaging. Both the long-wavelength NIR-II fluorescence imaging and PA imaging reveal that the as-fabricated BP@lipid-PEG nanospheres can be gradually metabolized by the liver in 48 h, thus making them promising for bioapplications.

Second near-infrared photodynamic therapy and chemotherapy of orthotopic malignant glioblastoma with ultra-small Cu2-xSe nanoparticles

The treatment of malignant glioblastoma is a huge challenge due to the existence of the blood-brain barrier. Herein, we report the treatment of orthotopic malignant glioblastoma with imaging guided second near-infrared (NIR-II) photodynamic therapy and chemotherapy by using drug-loaded ultra-small Cu2-xSe theranostic nanoparticles (NPs). Ultra-small Cu2-xSe NPs possess a strong absorbance in the NIR-II window, and their absorption at 1064 nm is around 2 times that at 808 nm. Their strong NIR-II absorbance and the deeper-tissue penetration of NIR-II light ensure excellent photodynamic therapy performance under irradiation with a 1064 nm laser. We also demonstrate that ultra-small Cu2-xSe NPs can produce vast amounts of reactive oxygen species via electron transfer (for ˙OH generation) and energy transfer (for 1O2 generation) mechanisms under irradiation. In addition, these NPs can be effectively and locally transported into orthotopic malignant glioblastoma with the assistance of focused ultrasound. The deposited Cu2-xSe NPs can be used for photoacoustic imaging to guide the combined NIR-II photodynamic therapy and chemotherapy. The results show that the tumor growth can be significantly suppressed. This work demonstrates the great potential of drug-loaded ultra-small Cu2-xSe NPs as a promising therapeutic agent for the treatment of orthotopic malignant glioblastoma.

Boosting the Radiosensitizing and Photothermal Performance of Cu2- xSe Nanocrystals for Synergetic Radiophotothermal Therapy of Orthotopic Breast Cancer

The small difference between tumor and normal tissues in their responses to ionizing radiation has been a significant issue for radiotherapy of tumors. Herein, we report that dumbbell-shaped heterogeneous copper selenide-gold nanocrystals can serve as an efficient radiosensitizer for enhanced radiotherapy. The mean lethal dose of X-rays to 4T1 tumor cells can be drastically decreased about 40%, that is, decreasing from 1.81 to 1.10 Gy after culture with heterostructures. Due to the synergetic effect of heterostructures, the dose of X-rays is also much lower than those obtained from mixture of Cu_{2- x}Se + Au nanoparticles (1.78 Gy), Cu_{2- x}Se nanoparticles (1.72 Gy) and Au nanoparticles (1.50 Gy), respectively. We demonstrate that the sensitivity enhancement ratio of Cu_{2- x}Se nanoparticles was significantly improved 45% ( i. e., from 1.1 to 1.6) after the formation of heterostructures with gold. We also show that the heteronanocrystals exhibit an enhanced photothermal conversion efficiency, due to the synergetic interactions of localized surface plasmon resonance. These properties highly feature them as a multimodal imaging contrast agent (particularly for photoacoustic imaging, computed tomography imaging, and single photon emission computed tomography after labeled with radioisotopes) and as a radiosensitizer for imaging guided synergetic radiophotothermal treatment of cancer. The research provides insights for engineering low- Z nanomaterials with high- Z elements to form heteronanostructures with enhanced synergetic performance for tumor theranostics.

Biocompatible and multifunctional gold nanorods for effective photothermal therapy of oral squamous cell carcinoma

Functionalized gold nanorods were successfully synthesized for the effective photothermal therapy of oral cancer.