Anti-biofouling polymer-decorated lutetium-based nanoparticulate contrast agents for in vivo high-resolution trimodal imaging

Metabolomics-derived biomarkers for biosafety assessment of Gd-based nanoparticle magnetic resonance imaging contrast agents

With the rapid development of nanotechnology and biomedicine, numerous gadolinium (Gd)-based nanoparticle MRI contrast agents have been widely investigated. Due to the unique physicochemical properties of nanoparticles and the complexity of biological systems, the biosafety of Gd-based nanoparticle MRI contrast agents has been paid more and more attention. Herein, for the first time, we employed an ultra-high performance liquid chromatography-electrospray ionization quadrupole time-of-flight/mass spectrometry (UPLC-ESI-QTOF/MS)-based metabolomics approach to investigate the potential toxicity of Gd-based nanoparticle MRI contrast agents. In this work, NaGdF4 and PEG-NaGdF4 nanoparticles were successfully constructed and selected as the representative Gd-based nanoparticle MRI contrast agents for the metabolomics analysis. Based on the results of metabolomics, more metabolic biomarkers and pathways were identified in the NaGdF4 group than those in the PEG-NaGdF4 group. Careful analysis of these metabolic biomarkers and pathways suggested that NaGdF4 nanoparticles induced disturbance of pyrimidine and purine metabolism, inflammatory response, and kidney injury to a certain extent compared with PEG-NaGdF4 nanoparticles. These results indicated that Gd-based nanoparticle contrast agents modified with PEG had better biosafety. Additionally, it was demonstrated that the discovery of characteristic metabolomics biomarkers induced by nanoparticles would provide a new approach for biosafety assessment and stimulate the development of nanomedicine.

Engineered upconversion nanocarriers for synergistic breast cancer imaging and therapy: Current state of art

Breast cancer is the most common type of cancer in women and is the second leading cause of cancer-related deaths worldwide. Early diagnosis and effective therapeutic interventions are critical determinants that can improve survival and quality of life in breast cancer patients. Nanotheranostics are emerging interventions that offer the dual benefit of in vivo diagnosis and therapeutics through a single nano-sized carrier. Rare earth metal-doped upconversion nanoparticles (UCNPs) with their ability to convert near-infrared light to visible light or UV light in vivo settings have gained special attraction due to their unique luminescence and tumor-targeting properties. In this review, we have discussed applications of UCNPs in drug and gene delivery, photothermal therapy (PTT), photodynamic therapy (PDT) and tumor targeting in breast cancer. Further, present challenges and future opportunities for UCNPs in breast cancer treatment have also been mentioned.

Safety and efficacy of citric acid-upconverting nanoparticles for multimodal biological imaging in BALB/c mice

There has been significant progress with rare-earth coated upconversion nanoparticles (UCNPs) representing a promising new generation of contrast agents for biomedical applications. However, in vivo biological safety remains poorly investigated. This work examined citric acid-UCNP (NaYF4:Yb³⁺/Gd³⁺, ∼ 5 nm, Cit-UCNP) generated as contrast agents for multimodal imaging with concurrent magnetic resonance (MRI) and X-ray computed tomography (CT). We first examined the in vitro cytotoxicity and efficacy of Cit-UCNPs as a contrast agent. We then performed a systematic investigation of their in vivo biodistribution and biocompatibility. Our results noted that Cit-UCNPs have minimal toxicity and demonstrated significant potential as contrast agents for multimodal biomedical imaging. This study indicates Cit-UCNPs could be a valuable addition to enhance long-term targeted diagnostic and prognostic multimodal clinical imaging approaches.

Pharmacokinetics of Single Domain Antibodies and Conjugated Nanoparticles Using a Hybrid near Infrared Method

Iron oxide nanoparticles and single domain antibodies from camelids (VHHs) have been increasingly recognized for their potential uses for medical diagnosis and treatment. However, there have been relatively few detailed characterizations of their pharmacokinetics (PK). The aim of this study was to develop imaging methods and pharmacokinetic models to aid the future development of a novel family of brain MRI molecular contrast agents. An efficient near-infrared (NIR) imaging method was established to monitor VHH and VHH conjugated nanoparticle kinetics in mice using a hybrid approach: kinetics in blood were assessed by direct sampling, and kinetics in kidney, liver, and brain were assessed by serial in vivo NIR imaging. These studies were performed under "basal" circumstances in which the VHH constructs and VHH-conjugated nanoparticles do not substantially interact with targets nor cross the blood brain barrier. Using this approach, we constructed a five-compartment PK model that fits the data well for single VHHs, engineered VHH trimers, and iron oxide nanoparticles conjugated to VHH trimers. The establishment of the feasibility of these methods lays a foundation for future PK studies of candidate brain MRI molecular contrast agents.

Antifouling Strategies of Nanoparticles for Diagnostic and Therapeutic Application: A Systematic Review of the Literature

Nanoparticles (NPs) are promising platforms for the development of diagnostic and therapeutic tools. One of the main hurdle to their medical application and translation into the clinic is the fact that they accumulate in the spleen and liver due to opsonization and scavenging by the mononuclear phagocyte system. The “protein corona” controls the fate of NPs in vivo and becomes the interface with cells, influencing their physiological response like cellular uptake and targeting efficiency. For these reasons, the surface properties play a pivotal role in fouling and antifouling behavior of particles. Therefore, surface engineering of the nanocarriers is an extremely important issue for the design of useful diagnostic and therapeutic systems. In recent decades, a huge number of studies have proposed and developed different strategies to improve antifouling features and produce NPs as safe and performing as possible. However, it is not always easy to compare the various approaches and understand their advantages and disadvantages in terms of interaction with biological systems. Here, we propose a systematic study of literature with the aim of summarizing current knowledge on promising antifouling coatings to render NPs more biocompatible and performing for diagnostic and therapeutic purposes. Thirty-nine studies from 2009 were included and investigated. Our findings have shown that two main classes of non-fouling materials (i.e., pegylated and zwitterionic) are associated with NPs and their applications are discussed here highlighting pitfalls and challenges to develop biocompatible tools for diagnostic and therapeutic uses. In conclusion, although the complexity of biofouling strategies and the field is still young, the collective data selected in this review indicate that a careful tuning of surface moieties is a pivotal step to lead NPs through their future clinical applications.

Multifunctional HNT@Fe3O4@PPy@DOX Nanoplatform for Effective Chemo-Photothermal Combination Therapy of Breast Cancer with MR Imaging

Multifunctional nanoparticles for imaging and treatment in cancer are getting more and more attention recently. Herein, halloysite nanotubes (HNTs), natural clay nanotubes, are designed as multifunctional nanoplatform for targeted delivering photothermal therapy agents and chemotherapeutic drugs. Fe₃O₄ was anchored on the outer surfaces of HNTs and then doxorubicin (DOX) was loaded on the nanotubes. Afterward, a layer of polypyrrole (PPy), as photothermal agent, was wrapped on the tubes. The nanoplatform of HNT@Fe₃O₄@PPy@DOX can be guided to tumor tissue by an external magnetic field, and then performs chemo-photothermal combined therapy by 808 nm laser irradiation. HNT@Fe₃O₄@PPy@DOX shows the ability of T₂-weighted magnetic resonance imaging, which could be considered as a promising application in magnetic targeting tumor therapy. In vitro and in vivo experiments demonstrate that HNTs nanoplatform has good biocompatibility and produces a strong antitumor effect trigged by near-infrared laser irradiation. The novel chemo-photothermal therapy nanoplatform based on HNTs may be developed as a multifunctional nanoparticle for imaging and therapy in breast cancer.

Nanoscale dynamic chemical, biological sensor material designs for control monitoring and early detection of advanced diseases

Early detection and easy continuous monitoring of emerging or re-emerging infectious, contagious or other diseases are of particular interest for controlling healthcare advances and developing effective medical treatments to reduce the high global cost burden of diseases in the backdrop of lack of awareness regarding advancing diseases. Under an ever-increasing demand for biosensor design reliability for early stage recognition of infectious agents or contagious diseases and potential proteins, nanoscale manufacturing designs had developed effective nanodynamic sensing assays and compact wearable devices. Dynamic developments of biosensor technology are also vital to detect and monitor advanced diseases, such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), diabetes, cancers, liver diseases, cardiovascular diseases (CVDs), tuberculosis, and central nervous system (CNS) disorders. In particular, nanoscale biosensor designs have indispensable contribution to improvement of health concerns by early detection of disease, monitoring ecological and therapeutic agents, and maintaining high safety level in food and cosmetics. This review reports an overview of biosensor designs and their feasibility for early investigation, detection, and quantitative determination of many advanced diseases. Biosensor strategies are highlighted to demonstrate the influence of nanocompact and lightweight designs on accurate analyses and inexpensive sensing assays. To date, the effective and foremost developments in various nanodynamic designs associated with simple analytical facilities and procedures remain challenging. Given the wide evolution of biosensor market requirements and the growing demand in the creation of early stage and real-time monitoring assays, precise output signals, and easy-to-wear and self-regulating analyses of diseases, innovations in biosensor designs based on novel fabrication of nanostructured platforms with active surface functionalities would produce ​remarkable biosensor devices. This review offers evidence for researchers and inventors to focus on biosensor challenge and improve fabrication of nanobiosensors to revolutionize consumer and healthcare markets.

Multifunctional graphene oxide/iron oxide nanoparticles for magnetic targeted drug delivery dual magnetic resonance/fluorescence imaging and cancer sensing

Graphene Oxide (GO) has recently attracted substantial attention in biomedical field as an effective platform for biological sensing, tissue scaffolds and in vitro fluorescence imaging. However, the targeting modality and the capability of its in vivo detection have not been explored. To enhance the functionality of GO, we combine it with superparamagnetic iron oxide nanoparticles (Fe3O4 NPs) serving as a biocompatible magnetic drug delivery addends and magnetic resonance contrast agent for MRI. Synthesized GO-Fe3O4 conjugates have an average size of 260 nm and show low cytotoxicity comparable to that of GO. Fe3O4 nanoparticles provide superparamagnetic properties for magnetic targeted drug delivery allowing simple manipulation by the magnetic field and magnetic resonance imaging with high r2/r1 relaxivity ratios of ~10.7. GO-Fe3O4 retains pH-sensing capabilities of GO used in this work to detect cancer versus healthy environments in vitro and exhibits fluorescence in the visible for bioimaging. As a drug delivery platform GO-Fe3O4 shows successful fluorescence-tracked transport of hydrophobic doxorubicin non-covalently conjugated to GO with substantial loading and 2.5-fold improved efficacy. As a result, we propose GO-Fe3O4 nanoparticles as a novel multifunctional magnetic targeted platform for high efficacy drug delivery traced in vitro by GO fluorescence and in vivo via MRI capable of optical cancer detection.

Targeted Molecular Magnetic Resonance Imaging Detects Brown Adipose Tissue with Ultrasmall Superparamagnetic Iron Oxide

The peptide (CKGGRAKDC-NH2) specifically targets the brown adipose tissue (BAT). Here we applied this peptide coupled with polyethylene glycol (PEG)-coated ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles to detect BAT in vivo by magnetic resonance imaging (MRI). The peptide was conjugated with PEG-coated USPIO nanoparticles to obtain targeted USPIO nanoprobes. Then the nanoprobes for BAT were evaluated in mice. T2⁎-weighted images were performed, precontrast and postcontrast USPIO nanoparticles. Finally, histological analyses proved the specific targeting. The specificity of targeted USPIO nanoprobes was observed in mice. The T2⁎ relaxation time of BAT in the targeted group decreased obviously compared to the controls (P<0.001). Prussian blue staining and transmission electron microscope confirmed the specific presence of iron oxide. This study demonstrated that peptide (CKGGRAKDC-NH2) coupled with PEG-coated USPIO nanoparticles could identify BAT noninvasively in vivo with MRI.

Multifunctional Carbon-Based Nanomaterials: Applications in Biomolecular Imaging and Therapy

Molecular imaging has been widely used not only as an important detection technology in the field of medical imaging for cancer diagnosis but also as a theranostic approach for cancer in recent years. Multifunctional carbon-based nanomaterials (MCBNs), characterized by unparalleled optical, electronic, and thermal properties, have attracted increasing interest and demonstrably hold the greatest promise in biomolecular imaging and therapy. As such, it should come as no surprise that MCBNs have already revealed a great deal of potential applications in biomedical areas, such as bioimaging, drug delivery, and tumor therapy. Carbon nanomaterials can be categorized as graphene, single-walled carbon nanotubes, mesoporous carbon, nanodiamonds, fullerenes, or carbon dots on the basis of their morphologies. In this article, reports of the use of MCBNs in various chemical conjugation/functionalization strategies, focusing on their applications in cancer molecular imaging and imaging-guided therapy, will be comprehensively summarized. MCBNs show the possibility to serve as optimal candidates for precise cancer biotheranostics.

Polydopamine encapsulation of fluorescent nanodiamonds for biomedical applications

Fluorescent nanodiamonds (FNDs) are promising bio-imaging probes compared with other fluorescent nanomaterials such as quantum dots, dye-doped nanoparticles, and metallic nanoclusters, due to their remarkable optical properties and excellent biocompatibility. Nevertheless, they are prone to aggregation in physiological salt solutions, and modifying their surface to conjugate biologically active agents remains challenging. Here, inspired by the adhesive protein of marine mussels, we demonstrate encapsulation of FNDs within a polydopamine (PDA) shell. These PDA surfaces are readily modified via Michael addition or Schiff base reactions with molecules presenting thiol or nitrogen derivatives. We describe modification of PDA shells by thiol terminated poly(ethylene glycol) (PEG-SH) molecules to enhance colloidal stability and biocompatibility of FNDs. We demonstrate their use as fluorescent probes for cell imaging; we find that PEGylated FNDs are taken up by HeLa cells and mouse bone marrow-derived dendritic cells and exhibit reduced nonspecific membrane adhesion. Furthermore, we demonstrate functionalization with biotin-PEG-SH and perform long-term high-resolution single-molecule fluorescence based tracking measurements of FNDs tethered via streptavidin to individual biotinylated DNA molecules. Our robust polydopamine encapsulation and functionalization strategy presents a facile route to develop FNDs as multifunctional labels, drug delivery vehicles, and targeting agents for biomedical applications.

Double-Targeting Explosible Nanofirework for Tumor Ignition to Guide Tumor-Depth Photothermal Therapy

This study reports a double-targeting "nanofirework" for tumor-ignited imaging to guide effective tumor-depth photothermal therapy (PTT). Typically, ≈30 nm upconversion nanoparticles (UCNP) are enveloped with a hybrid corona composed of ≈4 nm CuS tethered hyaluronic acid (CuS-HA). The HA corona provides active tumor-targeted functionality together with excellent stability and improved biocompatibility. The dimension of UCNP@CuS-HA is specifically set within the optimal size window for passive tumor-targeting effect, demonstrating significant contributions to both the in vivo prolonged circulation duration and the enhanced size-dependent tumor accumulation compared with ultrasmall CuS nanoparticles. The tumors featuring hyaluronidase (HAase) overexpression could induce the escape of CuS away from UCNP@CuS-HA due to HAase-catalyzed HA degradation, in turn activating the recovery of initially CuS-quenched luminescence of UCNP and also driving the tumor-depth infiltration of ultrasmall CuS for effective PTT. This in vivo transition has proven to be highly dependent on tumor occurrence like a tumor-ignited explosible firework. Together with the double-targeting functionality, the pathology-selective tumor ignition permits precise tumor detection and imaging-guided spatiotemporal control over PTT operation, leading to complete tumor ablation under near infrared (NIR) irradiation. This study offers a new paradigm of utilizing pathological characteristics to design nanotheranostics for precise detection and personalized therapy of tumors.

Surface manganese substitution in magnetite nanocrystals enhances T1 contrast ability by increasing electron spin relaxation

Magnetite nanoparticles, with good biocompatibility and favorable magnetic properties, have the potential to be the best candidate for non-gadolinium MRI contrast agents. However, they usually show low T₁ contrast ability, largely because Fe(ii) ions have a short electronic relaxation time and also have a small number of unpaired electrons with inefficient proton relaxation enhancement. Herein, we report a novel strategy to increase the T₁ contrast ability of magnetite nanoparticles, through substituting the undesirable Fe(ii) ions with Mn(ii) ions. Mn(ii) ions have a longer electronic relaxation time (10^-8 s) and more unpaired electrons (5 unpaired electrons). We successfully construct diverse-shaped manganese ferrite nanoparticles with abundant magnetic ions, Mn(ii) and Fe(iii), exposed on the surface. These manganese ferrite nanoparticles exhibit remarkably higher longitudinal relaxivity than their parent iron oxide nanoparticles. We demonstrate that the increase in T₁ relaxivity is attributed to the extended electronic relaxation time and the increased number of unpaired electrons on the surface of the nanoparticles by controlling surface features, particularly by adjusting the substitution degree of Mn(ii) ions and in situ coating. This study provides an insightful strategy to improve the T₁ contrast ability of iron oxide nanoparticles, which is urgently needed for developing high-performance non-gadolinium T₁ contrast agents for imaging and diagnosis of disease.

An RGD-modified hollow silica@Au core/shell nanoplatform for tumor combination therapy

The combination of chemotherapy and photothermal therapy (PTT) in multifunctional nanoplatforms to improve cancer therapeutic efficacy is of great significance while it still remains to be a challenging task. Herein, we report Au nanostar (NS)-coated hollow mesoporous silica nanocapsules (HMSs) with surface modified by arginine-glycine-aspartic acid (RGD) peptide as a drug delivery system to encapsulate doxorubicin (DOX) for targeted chemotherapy and PTT of tumors. Au NSs-coated HMSs core/shell nanocapsules (HMSs@Au NSs) synthesized previously were conjugated with RGD peptide via a spacer of polyethylene glycol (PEG). We show that the prepared HMSs@Au-PEG-RGD NSs are non-cytotxic in the given concentration range, and have a DOX encapsulation efficiency of 98.6±0.7%. The designed HMSs@Au-PEG-RGD NSs/DOX system can release DOX in a pH/NIR laser dual-responsive manner. Importantly, the formed HMSs@Au-PEG-RGD NSs/DOX nanoplatform can specifically target cancer cells overexpressing α_vβ₃ intergrin and exert combination chemotherapy and PTT efficacy to the cells in vitro and a xenografted tumor model in vivo. Our results suggest that the designed HMSs@Au-PEG-RGD NSs/DOX nanoplatform may be used for combination chemotherapy and PTT of tumors.

STATEMENT OF SIGNIFICANCE

We demonstrate a convenient approach to preparing a novel RGD-targeted drug delivery system of HMSs@Au-PEG-RGD NSs/DOX that possesses pH/NIR laser dual-responsive drug delivery performance for combinational chemotherapy and PTT of tumors. The developed Au NS-coated HMS capsules have both merits of HMS capsules that can be used for high payload drug loading and Au NSs that have NIR laser-induced photothermal conversion efficiency (70.8%) and can be used for PTT of tumors.

In situ synthesis of NIR-light emitting carbon dots derived from spinach for bio-imaging applications

Near infrared (NIR)-light emitting fluorescent probes have attracted extensive research attention in the bioimaging field due to their deep tissue penetration, minimal auto-fluorescence and lower emission light damage to bio-tissues. Herein, we designed and prepared NIR-light emitting CDs (R-CDs) from spinach by a one-step solvothermal method. The R-CDs exhibited good water solubility, a maximum fluorescence emission peak at 680 nm, a high quantum yield of 15.34%, remarkable photo-stability and resistance to metal ions in a body-simulating environment, excellent compatibility, negligible toxicity, and superior labelling capability in vitro and in vivo. These findings significantly highlight the design of NIR-light emitting CDs and exploit their bio-imaging applications.

Surfactant-stripped naphthalocyanines for multimodal tumor theranostics with upconversion guidance cream

Surfactant-stripped, nanoformulated naphthalocyanines (nanonaps) can be formed with Pluronic F127 and low temperature membrane processing, resulting in dispersed frozen micelles with extreme contrast in the near infrared region. Here, we demonstrate that nanonaps can be used for multifunctional cancer theranostics. This includes lymphatic mapping and whole tumor photoacoustic imaging following intradermal or intravenous injection in rodents. Without further modification, pre-formed nanonaps were used for positron emission tomography and passively accumulated in subcutaneous murine tumors. Because the nanonaps used absorb light beyond the visible range, a topical upconversion skin cream was developed for anti-tumor photothermal therapy with laser placement that can be guided by the naked eye.

Nanopolymersomes with an Ultrahigh Iodine Content for High-Performance X-Ray Computed Tomography Imaging In Vivo

Biocompatible and biodegradable nanopolymersomes with an unprecedented iodine content, low viscosity, and iso-osmolality achieve significantly enhanced CT imaging of blood pool and the reticuloendothelial system. Moreover, in subcutaneous and orthotopic tumor models in mice, they show enhanced in vivo imaging when compared to iohexol, a clinically used small-molecule contrast agent.

Formation of Gold Nanostar-Coated Hollow Mesoporous Silica for Tumor Multimodality Imaging and Photothermal Therapy

Development of multifunctional nanoplatforms for tumor multimode imaging and therapy is of great necessity. Herein, we report a new type of Au nanostar (NS)-coated, perfluorohexane (PFH)-encapsulated hollow mesoporous silica nanocapsule (HMS) modified with poly(ethylene glycol) (PEG) for tumor multimode ultrasonic (US)/computed tomography (CT)/photoacoustic (PA)/thermal imaging, and photothermal therapy (PTT). HMSs were first synthesized, silanized to have thiol surface groups, and coated with gold nanoparticles via a Au-S bond. Followed by growth of Au NSs on the surface of the HMSs, encapsulation of PFH in the interior of the HMSs, and surface conjugation of thiolated PEG, multifunctional HMSs@Au-PFH-mPEG NSs (for short, HAPP) were formed and well-characterized. We show that the HAPP are stable in a colloidal manner and noncytotoxic in the studied range of concentrations, possess multimode US/CT/PA/thermal imaging ability, and can be applied for multimode US/CT/PA/thermal imaging of tumors in vivo after intravenous or intratumoral injection. Additionally, the near-infrared absorption property of the HAPP enables the use of the HAPP for photothermal ablation of cancer cells in vitro and a tumor model in vivo after intratumoral injection. The developed multifunctional HAPP may be used as a novel multifunctional theranostic nanoplatform for tumor multimode imaging and PTT.

Hyaluronate modified upconversion nanoparticles for near infrared light-triggered on–off tattoo systems

We successfully developed an NIR light-triggered in vivo on–off tattoo system using hyaluronate modified upconversion nanoparticles for various biomedical applications.

A colloidally stable water dispersion of Ni nanowires as an efficient T2-MRI contrast agent

A colloidally stable dispersion of anisotropic Ni nanowires in water has been achieved showing good performance as a T₂-contrast agent in MRI.

Engineered gadolinium-doped carbon dots for magnetic resonance imaging-guided radiotherapy of tumors

The effectiveness of radiotherapy can decrease due to inaccurate positioning of machinery and inherent radioresistance of tumors. To address this issue, we present a novel theranostic nanoplatform based on gadolinium-doped carbon dots (Gd-doped CDs) designed specifically for magnetic resonance imaging (MRI)-guided radiotherapy of tumors. The Gd-doped CDs (∼18 nm) with dispersibility in water and stable photoluminescence were synthesized via a one-step hydrothermal approach. After tail vein injection of the Gd-doped CDs, they exhibited a relatively long circulation time (∼6 h), enabled efficient passive tumor targeting. Gd-doped CDs accumulate in the kidney and could be cleared out of the body from bladder. Importantly, they exhibited favorable biocompatibility with excellent performance in longitudinal relaxivity rate (r₁) of 6.45 mM^-1S^-1 and radiosensitization enhancements. These results show that Gd-doped CDs are excellent T₁ contrast agents and radiosensitizers, possessing great promise for MRI-guided radiotherapy of tumors.

Small is Smarter: Nano MRI Contrast Agents - Advantages and Recent Achievements

Many challenges for advanced sensitive and noninvasive clinical diagnostic imaging remain unmatched. In particular, the great potential of magnetic nano-probes is intensively discussed to further improve the performance of magnetic resonance imaging (MRI), especially for cancer diagnosis. Based on recent achievements, here the concepts of magnetic nanoparticle-based MRI contrast agents and tumor-specific imaging probes are critically summarized. Advances in their synthesis, biocompatible chemical and biofunctional surface modifications, and current strategies for further developing them into multimodality imaging probes are discussed. In addition, how engineered versus unintended surface coatings such as protein coronas affect the biocompatibility and performance of MRI nano-probes is also considered. To stimulate progress in the field, future strategies and relevant challenges that still need to be resolved in the field conclude this review.

Synthesis and formation mechanisms of morphology-controllable indium-containing precursors and optical properties of the derived In2O3 particles

Indium-containing precursors with three morphologies were synthesized, and the formation mechanisms were analyzed.

Conformational switch-mediated accelerated release of drug from cytosine-rich nucleic acid-capped magnetic nanovehicles

A novel concept that the conformational switch of cytosine-rich DNA can accelerate the release of drug from DNA-capped nanovehicles is rationally devised.

Upconversion nanocomposites for photo-based cancer theranostics

Upconversion nanoparticles (UCNPs) are able to convert long wavelength excitation light into high energy ultraviolet (UV) or visible emissions, and they have attracted significant attention because of their distinct photochemical properties including sharp emission bands, low autofluorescence, high tissue penetration depth and minimal photodamage to tissues.

Using Plasmonic Copper Sulfide Nanocrystals as Smart Light-Driven Sterilants

As an efficient route to control pet overpopulation and develop neutered experimental animals, male sterilization via surgical techniques, chemical injections, and antifertility vaccines has brought particular attention recently. However, these traditional ways usually induce long-term adverse reactions, immune suppression, and serious infection and pain. To overcome the above limitations, we developed a platform in the present study by using plasmonic copper sulfide nanocrystals (Cu2-xS NCs) as intelligent light-driven sterilants with ideal outcomes. Upon NIR laser irradiation, these well-prepared Cu2-xS NCs can possess NIR-induced hyperthermia and generate high levels of reactive oxygen species (ROS). Due to the cooperation of photothermal and photodynamic effects, these nanocrystals exhibited NIR-mediated toxicity toward Sertoli cells both in vitro and in vivo in a mild manner. We attribute the potential mechanism of cellular injury to the apoptosis-related death and denaturation of protein in the testicles. Furthermore, the possible metabolism route and long-term toxicity of these nanocrystals after testicular injection indicate their high biocompatibility. Taking together, our study on the NIR-induced toxicity of Cu2-xS NCs provides keen insights for the usage of plasmonic nanomaterials in biomedicine.

Single-layer tungsten oxide as intelligent photo-responsive nanoagents for permanent male sterilization

Permanent male sterilization has been recognized as useful tools for the development of neuter experimental animals and fattening livestock, as well as efficient control of pet overpopulation. Traditional routes such as surgical ways, chemical injections, and anti-fertility vaccines have addressed these crucial problems with idea outcomes. However, these routes usually bring out serious pain and infection towards animals, as well as induce long-term adverse reaction and immune suppression. Thus, a convenient, but non-surgical strategy for male sterilization under a mild manner is highly desirable. Here, for the first time, we demonstrate a novel platform for male sterilization by using single-layer WO2.72 nanosheets as smart photo-responsive sterilants. Upon a 980 nm irradiation, these nanoagents can possess intrinsic NIR-induced hyperthermia and sensitize the formation of singlet oxygen due to the cooperation of photothermal and photodynamic effects. Mechanism of cellular injury can be attributed to the denaturation of protein and apoptosis-related death. Moreover, long-term toxicity and possible metabolism route after testicular injection are discussed, indicating the neglectable systemic toxicity and high bio-compatibility of our nanoagents. Overall, our strategy can extremely overcome the shortcomings in various routine routes and suggest the new biological application of nanomaterials.

Graphene Oxide as a Multifunctional Platform for Raman and Fluorescence Imaging of Cells

Fluorescence and Raman bimodal imaging and Raman multifrequency imaging of Hela cells are carried out with the help of two kinds of graphene oxide-based hybrids. As a multifunctional platform, graphene oxide acts as not only a Raman probe, but also as a substrate for Raman and fluorescent probes to load on.

An efficient nano-based theranostic system for multi-modal imaging-guided photothermal sterilization in gastrointestinal tract

Since understanding the healthy status of gastrointestinal tract (GI tract) is of vital importance, clinical implementation for GI tract-related disease have attracted much more attention along with the rapid development of modern medicine. Here, a multifunctional theranostic system combining X-rays/CT/photothermal/photoacoustic mapping of GI tract and imaging-guided photothermal anti-bacterial treatment is designed and constructed. PEGylated W18O49 nanosheets (PEG-W18O49) are created via a facile solvothermal method and an in situ probe-sonication approach. In terms of excellent colloidal stability, low cytotoxicity, and neglectable hemolysis of PEG-W18O49, we demonstrate the first example of high-performance four-modal imaging of GI tract by using these nanosheets as contrast agents. More importantly, due to their intrinsic absorption of NIR light, glutaraldehyde-modified PEG-W18O49 are successfully applied as fault-free targeted photothermal agents for imaging-guided killing of bacteria on a mouse infection model. Critical to pre-clinical and clinical prospects, long-term toxicity is further investigated after oral administration of these theranostic agents. These kinds of tungsten-based nanomaterials exhibit great potential as multi-modal contrast agents for directed visualization of GI tract and anti-bacterial agents for phothothermal sterilization.

Hexamodal imaging with porphyrin-phospholipid-coated upconversion nanoparticles

Hexamodal imaging using simple nanoparticles is demonstrated. Porphyrin-phospholipids are used to coat upconversion nanoparticles in order to generate a new biocompatible material. The nanoparticles are characterized in vitro and in vivo for imaging via fluorescence, upconversion, positron emission tomography, computed tomography, Cerenkov luminescence, and photoacoustic tomography.

Multivalent manganese complex decorated amphiphilic dextran micelles as sensitive MRI probes

T₁ contrast agents based on Mn(II) were conjugated on amphiphilic dextran micelles via click chemistry. The obtained paramagnetic nanomicelle contrast agent has a higher T₁ relaxivity (13.3 Mn mmol^-1 s^-1) and better sensitivity than those of free Mn(II) complexes. Studies carried out in vivo suggest that this contrast agent has a better and long-acting vascular enhancement effect at a lower manganese dosage (0.1 Mn mmol kg^-1 BW).

An anion-induced hydrothermal oriented-explosive strategy for the synthesis of porous upconversion nanocrystals

Rare-earth (RE)-doped upconversion nanocrystals (UCNCs) are deemed as the promising candidates of luminescent nanoprobe for biological imaging and labeling. A number of methods have been used for the fabrication of UCNCs, but their assembly into porous architectures with desired size, shape and crystallographic phase remains a long-term challenging task. Here we report a facile, anion-induced hydrothermal oriented-explosive method to simultaneously control size, shape and phase of porous UCNCs. Our results confirmed the anion-induced hydrothermal oriented-explosion porous structure, size and phase transition for the cubic/hexagonal phase of NaLuF4 and NaGdF4 nanocrystals with various sizes and shapes. This general method is very important not only for successfully preparing lanthanide doped porous UCNCs, but also for clarifying the formation process of porous UCNCs in the hydrothermal system. The synthesized UCNCs were used for in vitro and in vivo CT imaging, and could be acted as the potential CT contrast agents.

Diagnostic imaging and therapeutic application of nanoparticles targeting the liver

Liver diseases, particularly viral hepatitis, cirrhosis and hepatocellular carcinoma, are common in clinical practice with high morbidity and mortality worldwide. Many substances for diagnostic imaging and therapy of liver diseases may have either severe adverse effects or insufficient effectiveness in vivo because of their nonspecific uptake. Therefore, by targeting the delivery of drugs into the liver or specific liver cells, drug efficiency may be largely improved. This review summarizes the up-to-date research progress focusing on nanoparticles targeting the liver for both diagnostic and therapeutic purposes. Targeting strategies, mechanisms of enhanced effects, and clinical applications of nanoparticles are discussed specifically. We believe that new targeting nanotechnology such as nanoprobes for multi-modality imaging and multifunctional nanoparticles would facilitate significant advancements in this active research area in the near future.

PEGylated Gd(OH)3 nanorods as metabolizable contrast agents for computed tomography imaging

PEGylated Gd(OH)₃ nanorods have been efficiently prepared via a facile and green hydrothermal route and used as a metabolizable computed tomography contrast agent for in vivo imaging.

Targeted CT imaging of human hepatocellular carcinoma using low-generation dendrimer-entrapped gold nanoparticles modified with lactobionic acid

Dendrimer-entrapped gold nanoparticles formed using low-generation dendrimers modified with PEGylated lactobionic acid as templates enable targeted CT imaging of human hepatocellular carcinoma.

Utilising polymers to understand diseases: advanced molecular imaging agents

This review describes how the highly tuneable size, shape and chemical functionality of polymeric molecular imaging agents provides a means to intimately probe the various mechanisms behind disease formation and behaviour.

Upconverting nanoparticles: assessing the toxicity

Based on a survey of existing studies, low nanotoxicity of lanthanide doped upconverting nanoparticles holds promise for their safety and suitability for biomedical detection and imaging.

One-pot and facile synthesis of anti-biofouling polymer-modified gadolinium-based nanoprobes for dual-modal imaging and long-lasting tracking

PEGylated gadolinium hydroxycarbonate nanoparticles have been designed and synthesized via a one-pot facile route and successfully applied as high-performance dual-modal contrast agents for X-ray CT and MR imaging.

Large-scale synthesis of PEGylated lutetium hydroxycarbonates as nanoparticulate contrast agents for X-ray CT imaging

PEGylated lutetium hydroxycarbonate nanoparticles have been prepared via a large-scale strategy and successfully used as high-performance contrast agents for X-ray computed tomography imaging with neglectable systemic toxicity.