Tumor-targeted Imaging Research Articles

Cell-Penetrating Peptidic GRP78 Ligand-Conjugated Iron Oxide Magnetic Nanoparticles for Tumor-Targeted Doxorubicin Delivery and Imaging.

Although chemotherapy is regarded as an essential option in cancer treatment, it is still far from being perfect. Inadequate tumor drug concentration and systemic toxicity along with broad biodistribution have diminished the utility of chemotherapy. Tumor-targeting peptide-conjugated multifunctional nanoplatforms have emerged as an effective strategy for site-directed tumor tissues in cancer treatment and imaging. Herein, Pep42-targeted iron oxide magnetic nanoparticles (IONPs) functionalized with β-cyclodextrin (ßCD) containing doxorubicin (DOX) (Fe3O4-ßCD-Pep42-DOX) were successfully developed. The physical effects of the prepared NPs were characterized by employing various techniques. Transmission electron microscopy (TEM) images disclosed that the developed Fe3O4-ßCD-Pep42-DOX nanoplatforms had a spherical morphology and a core-shell structure with a size of nearly 17 nm. Fourier transform infrared (FT-IR) spectroscopy showed that β-cyclodextrin, DOX, and Pep42 molecules were successfully loaded on the IONPs. In vitro cytotoxicity analysis revealed that the fabricated multifunctional Fe3O4-ßCD-Pep42 nanoplatforms possessed excellent biosafety toward BT-474, MDA-MB468 (cancerous cells), and MCF10A normal cells, while Fe3O4-ßCD-Pep42-DOX exhibited great cancer cell killing ability. The high cellular uptake along with intracellular trafficking of Fe3O4-ßCD-Pep42-DOX highlights the usefulness of the Pep42-targeting peptide. In vivo results strongly supported the in vitro results, i.e., significant tumor size reduction was observed by single-dose injection of Fe3O4-ßCD-Pep42-DOX into tumor-bearing mice. Interestingly, in vivo MR imaging (MRI) of Fe3O4-ßCD-Pep42-DOX revealed T2 contrast improvement in the tumor cells and therapeutic ability in cancer theranostics. Taken together, these findings provided strong evidence for the potential capability of Fe3O4-ßCD-Pep42-DOX as a multifunctional nanoplatform in cancer therapy and imaging and opens up a new avenue of research in this area.

Membrane dual-targeting probes: A promising strategy for fluorescence-guided prostate cancer surgery and lymph node metastases detection.

Fluorescence-guided surgery (FGS) with tumor-targeted imaging agents, particularly those using the near-infrared wavelength, has emerged as a real-time technique to highlight the tumor location and margins during a surgical procedure. For accurate visualization of prostate cancer (PCa) boundary and lymphatic metastasis, we developed a new approach involving an efficient self-quenched near-infrared fluorescence probe, Cy-KUE-OA, with dual PCa-membrane affinity. Cy-KUE-OA specifically targeted the prostate-specific membrane antigen (PSMA), anchored into the phospholipids of the cell membrane of PCa cells and consequently showed a strong Cy7-de-quenching effect. This dual-membrane-targeting probe allowed us to detect PSMA-expressing PCa cells both invitro and invivo and enabled clear visualization of the tumor boundary during fluorescence-guided laparoscopic surgery in PCa mouse models. Furthermore, the high PCa preference of Cy-KUE-OA was confirmed on surgically resected patient specimens of healthy tissues, PCa, and lymph node metastases. Taken together, our results serve as a bridge between preclinical and clinical research in FGS of PCa and lay a solid foundation for further clinical research.

Bimetallic Hyaluronate-Modified Au@Pt Nanoparticles for Noninvasive Photoacoustic Imaging and Photothermal Therapy of Skin Cancer.

Although spherical gold (Au) nanoparticles have remarkable photothermal conversion efficiency and photostability, their weak absorption in the near-infrared (NIR) region and poor penetration into deep tissues have limited further applications to NIR light-mediated photoacoustic (PA) imaging and noninvasive photothermal cancer therapy. Here, we developed bimetallic hyaluronate-modified Au-platinum (HA-Au@Pt) nanoparticles for noninvasive cancer theranostics by NIR light-mediated PA imaging and photothermal therapy (PTT). The growth of Pt nanodots on the surface of spherical Au nanoparticles enhanced the absorbance in the NIR region and broadened the absorption bandwidth of HA-Au@Pt nanoparticles by the surface plasmon resonance (SPR) coupling effect. In addition, HA facilitated the transdermal delivery of HA-Au@Pt nanoparticles through the skin barrier and enabled clear tumor-targeted PA imaging. Compared to conventional PTT via injection, HA-Au@Pt nanoparticles were noninvasively delivered into deep tumor tissues and completely ablated the targeted tumor tissues by NIR light irradiation. Taken together, we could confirm the feasibility of HA-Au@Pt nanoparticles as a NIR light-mediated biophotonic agent for noninvasive skin cancer theranostics.

Human Nanoplatelets as Living Vehicles for Tumor-Targeted Endocytosis In Vitro and Imaging In Vivo

Recent studies have shown human platelets can access the tumor microenvironment by passive diffusion across capillaries or via activated immune cells. In a previous study, we exploited this affinity of platelets for tumor cells as part of a new approach to target tumors with modified platelets. Therefore, the engineering of human nanoplatelets as living vehicles for in vivo tumor-targeted near-infra-red fluorescence (NIRF) imaging and the delivery of cytotoxins to tumor cells by endocytosis are described in this study. Nanoplatelets with an average diameter of 200 nm were prepared by mild sonication of kabiramide C (KabC)-loaded human platelets. The sealed plasma membrane of the nanoplatelets allows them to accumulate and retain membrane-permeable chemicals, such as epidoxorubicin (EPI) and KabC. Tumor-targeted imaging functionalities were engineered on the nanoplatelets by surface-coupling transferrin, Cy5 and Cy7. High-resolution fluorescence imaging and flow cytometry analyses showed that the nanoplatelets loaded with EPI and Cy5 targeted human myeloma cells (RPMI8226 cells) that over-expressed the transferrin receptor. The endocytosis of the nanoplatelets by RPMI8226 cells was transferrin-dependent and induced apoptosis. The test results also showed that the nanoplatelets functionalized with transferrin and Cy7 and injected in mice bearing RPMI8226 cells-derived myeloma xenotransplants accumulated in the tumor tissue and could be used for high-contrast in vivo NIRF imaging of early-stage tumors. Nanoplatelets represent a new class of living nano-vehicles that may efficiently target and deliver therapeutic agents and imaging probes to diseased tissues including tumors.

Fluorescence Imaging-Incorporated Transcriptome Study of Glutathione Depletion-Enhanced Ferroptosis Therapy via Targeting Gold Nanoclusters.

Ferroptosis plays an important role in tumor inhibition and is a new type of programmed cell death. Recent studies have shown that glutathione (GSH) depletion is an effective method to enhance the therapeutic efficacy of ferroptosis; however, a systematic investigation of the phenomenon is limited. Herein, we provide a facile fluorescence imaging-incorporated transcriptome strategy to visualize the process and explore the mechanism of GSH depletion-enhanced ferroptosis. The proposed multifunctional nanoplatform is achieved using simple transferrin receptor aptamer-functionalized fluorescent gold nanoclusters (termed TfRA-AuNCs), which exhibit efficient hydroxyl radical generation and GSH-depleting capabilities. Live cell fluorescence imaging results revealed that TfRA-AuNCs were endocytosed into 4T1 cells and were mostly distributed in lysosomes. In vitro results indicated that TfRA-AuNCs enhanced the ferroptosis effect in 4T1 cells. Importantly, transcriptome analysis indicated that 4T1 cells treated with TfRA-AuNCs regulated the expression change of ferroptosis-related genes, and the Kyoto Encyclopedia of Genes and Genomes pathway identified the GSH metabolism pathway involved in ferroptosis, thus revealing the exact molecular mechanism of ferroptosis induced by TfRA-AuNCs at the RNA level. Furthermore, in vivo results confirmed the tumor inhibition effect, tumor-targeted fluorescence imaging, and long-term biocompatibility after TfRA-AuNC treatment. This study introduces a new possibility for the mechanistic study of nanoagent-induced ferroptosis in tumor treatment.

Enhanced Tumor Uptake and Retention of Cyanine Dye-Albumin Complex for Tumor-Targeted Imaging and Phototherapy.

Heptamethine cyanine dyes are widely used for in vivo near-infrared (NIR) fluorescence imaging and NIR laser-induced cancer phototherapy due to their good optical properties. Since most of heptamethine cyanine dyes available commercially are highly hydrophobic, they can usually be used for in vivo applications after formation of complexes with blood plasma proteins, especially serum albumin, to increase aqueous solubility. The complex formation between cyanine dyes and albumin improves the chemical stability and optical property of the hydrophobic cyanine dyes, which is the bottom of their practical use. In this study, the complexes between three different heptamethine cyanine dyes, namely clinically available indocyanine green (ICG), commercially available IR-786 and zwitterionic ZW800-Cl, and bovine serum albumin (BSA), were prepared to explore the effect of cyanine dyes on their tumor uptake and retention. Among the three complexes, IR-786©BSA exhibited increased tumor accumulation with prolonged tumor retention, compared to other complexes. Moreover, IR-786 bound to BSA played an important role in tumor growth suppression due to its cytotoxicity. To achieve complete tumor ablation, the tumor targeted by IR-786©BSA was further exposed to 808 nm laser irradiation for effective photothermal cancer treatment.

A covalent organic framework-derived M1 macrophage mimic nanozyme for precise tumor-targeted imaging and NIR-II photothermal catalytic chemotherapy.

Nanoprobes for efficient tumor-targeted imaging and therapy are urgently needed for clinical tumor theranostics. Herein, inspired by the heterogeneity of the tumor microenvironment, we report a covalent organic framework (COF)-derived biomimetic nanozyme for precise tumor-targeted imaging and NIR-II photothermal-catalysis-enhanced chemotherapy (PTCEC). Using a crystalline nanoscale COF as the precursor, a peroxidase-like porous N-doped carbonous nanozyme (PNC) was obtained, which was cloaked with an M1 macrophage cell membrane (M1m) to create a multifunctional biomimetic nanoprobe for tumor-targeted imaging and therapy. The M1m coating enabled the nanoprobe to target cancer cells and tumor tissues for highly efficient tumor imaging and drug delivery. The peroxidase-like activity of the PNC allowed for the conversion of intratumoral H2O2 into toxic ˙OH that synergized with its NIR-II photothermal effect to strengthen the chemotherapy. Therefore, highly efficient tumor-targeted imaging and NIR-II PTCEC were realized with an M1 macrophage mimic nanoprobe. This work provides a feasible tactic for a biomimetic theranostic nanoprobe and will inspire the development of new bioactive nanomaterials for clinical tumor theranostic applications.

Furan Donor for NIR-II Molecular Fluorophores with Enhanced Bioimaging Performance.

The second near-infrared (NIR-II, 1,000 to 1,700 nm) molecular fluorophores containing donor-acceptor-donor conjugated backbone have attracted substantial attention due to their outstanding advantages, such as stable emission and facilely tuned photophysical properties. However, it is still challenging for them to simultaneously achieve high brightness and red-shifted absorption and emission. Herein, furan is adopted as the D unit to construct NIR-II fluorophores, demonstrating red shift of absorption, enhanced absorption coefficient, and fluorescent quantum yield when compared with the generally used thiophene counterparts. The high brightness and desirable pharmacokinetics of the optimized fluorophore, IR-FFCHP, endows improved performance for angiography and tumor-targeting imaging. Furthermore, dual-NIR-II imaging of tumor and sentinel lymph nodes (LNs) has been achieved with IR-FFCHP and PbS/CdS quantum dots, enabling the in vivo imaging navigated LN surgery in tumor-bearing mice. This work demonstrates the potential of furan for constructing bright NIR-II fluorophores for biological imaging.

HA-AuNPs/FDF for Highly Sensitive Detection of Hyaluronidase, Tumor-targeting Fluorescence Cell Imaging and Phototherapy

HA-AuNPs/FDF for Highly Sensitive Detection of Hyaluronidase, Tumor-targeting Fluorescence Cell Imaging and Phototherapy

A tumor-targeting and ROS-responsive iron-based T1 magnetic resonance imaging contrast agent for highly specific tumor imaging.

T1 contrast agents (CAs) exhibit outstanding capacity in enhancing the magnetic resonance imaging (MRI) contrast between tumor tissues and normal tissues for generating bright images. However, the clinical application of representative gadolinium(III) chelate-based T1 CAs is limited due to their potential toxicity and low specificity for pathological tissues. To obtain MRI CAs with a combination of low toxicity and high tumor specificity, herein, we report a reactive oxygen species (ROS)-responsive T1 CA (GA-Fe(II)-PEG-FA), which was constructed by chelating Fe(II) with gallic acid (GA), and modified with tumor-targeted folic acid (FA). The resultant CA could accumulate in tumor tissues via the affinity between FA and their receptors on the tumor cell membrane. It realized the switch from Fe(II) to Fe(III), and further enhancing the longitudinal relaxation rate (r1) under the stimuli of ROS in the tumor microenvironment. The r1 of GA-Fe(II)-PEG-FA on a 0.5 T nuclear magnetic resonance analyzer increased to 2.20 mM-1 s-1 under ROS stimuli and was 5 times greater than the r1 (0.42 mM-1 s-1) before oxidation. The cell and in vivo experiments demonstrated that GA-Fe(II)-PEG-FA exhibited good biocompatibility and significant targeting specificity to tumor cells and tumor tissues. Furthermore, in vivo MRI studies demonstrated that the enhanced T1 contrast effect against tumors could be achieved after injecting the CA for 3 h, indicating that GA-Fe(II)-PEG-FA has the potential as an ideal tumor MRI CA to increase the contrast and improve the diagnostic precision.

A biocompatible polyurethane fluorescent emulsion with aggregation-induced emission for targeted tumor imaging.

The applications of fluorescence imaging in tumor detection and assistance in tumor resection have become progressively more widespread. Biocompatible fluorescent nanoparticles with high sensitivity and selectivity are a challenge for biological fluorescence imaging. Ligand-mediated targeting of nanoparticles to tumors is an appealing tactic for improving imaging efficiency. Herein, tetraphenyl ethylene (TPE) and phenylboronic acid (PBA) were introduced into polyurethane to synthesize a PU-TPE-PBA (PTP) fluorescent emulsion with aggregation-induced emission (AIE) for targeted tumor imaging. The PTP emulsion with a size of less than 50 nm shows excellent stability and high fluorescence sensitivity (extremely low TPE concentrations of 0.31 μg mL-1). Since PBA can selectively recognize and bind to sialic acid (SA) which is widely overexpressed in tumor cells, such PTP nanoparticles can be enriched in tumors and retained for longer periods due to enhanced permeability and retention (EPR) as well as active targeting effects. In addition, the PTP emulsion exhibits good biocompatibility and biosafety. Therefore, the novel PTP emulsion is promising for tumor cell imaging.

A simple one step synthesis of magnetic-optical dual functional ZIF-8 in a sodalite phase for magnetically guided targeting bioimaging and drug delivery.

Functionalized metal-organic frameworks (MOFs) that integrate targeted tumor imaging and drug delivery are expected to significantly enhance the therapeutic efficacy of cancer. However, the complicated synthesis process has greatly limited their utilization in clinical application. Herein, a one-step simple method was used to construct novel multifunctional MOFs by co-loading doxorubicin (DOX) and Fe3O4 into the ZIF-8 with sodalite topology. DOX serves as a fluorescence imaging reagent and an anticancer drug and Fe3O4 is used as a magnetic resonance imaging and magnetic targeting anticancer reagent. The fabricated DOX/Fe3O4@ZIF-8 nanocomposite showed excellent fluorescence and magnetic resonance imaging performances in tumors. Moreover, DOX/Fe3O4@ZIF-8 can be accumulated in tumors via a magnetic targeting effect and tumor growth could be inhibited in vivo due to the release of DOX. Additionally, the apoptosis process of DOX/Fe3O4@ZIF-8 on HepG2 cells is well investigated. Overall, DOX/Fe3O4@ZIF-8 synthesized in simple one step can be used for simultaneous targeted bioimaging and cancer therapy.

Tumor Targeting with Methotrexate-Conjugated Zwitterionic Near-Infrared Fluorophore for Precise Photothermal Therapy.

Targeted tumor imaging can effectively enable image-guided surgery and precise cancer therapy. Finding the right combination of anticancer drugs and near-infrared (NIR) fluorophores is the key to targeted photothermal cancer treatment. In this study, a tumor-targetable NIR fluorophore conjugate with rapid body clearance was developed for accurate tumor imaging and effective photothermal therapy (PTT). The methotrexate (MTX) and zwitterionic NIR fluorophore conjugate (MTX-ZW) were prepared by conjugating a folate antagonist MTX with an aminated ZW800-1 analog to increase the tumor targetability for NIR laser-based PTT of cancer. The MTX, known as a poor tumor-selective drug, showed high tumor accumulation and rapid background clearance after conjugation with the highly water-soluble zwitterionic NIR fluorophore up to 4 h post-injection. The photothermal energy was generated from the MTX-ZW conjugate to induce necrotic cell death in the targeted tumor site under 808 nm laser irradiation. Compared with the previously reported MTX conjugates, the MTX-ZW conjugate can be a great candidate for targeted tumor imaging and fluorescence-guided photothermal cancer therapy. Therefore, these results provide a strategy for the design of drug-fluorophore conjugates and elaborate therapeutic platforms for cancer phototherapy.

Tumor Targeting by Conjugation of Chlorambucil with Zwitterionic Near-Infrared Fluorophore for Cancer Phototherapy.

Improving the tumor targeting of anticancer drugs to minimize systemic exposure remains challenging. The chemical conjugation of anticancer drugs with various near-infrared (NIR) fluorophores may provide an effective approach to improve NIR laser-induced cancer phototherapy. Towards this end, the selection of NIR fluorophores conjugated with hydrophobic anticancer drugs is an important consideration for targeted cancer photothermal therapy (PTT). In this study, a highly water-soluble zwitterionic NIR fluorophore (ZW800) was prepared to conjugate with a water-insoluble anticancer drug, chlorambucil (CLB), to improve tumor targeting, in vivo biodistribution, and PTT performance. The in vivo results using an HT-29 xenograft mouse model demonstrated that the CLB-ZW800 conjugate not only exhibited high tumor accumulation within 4 h after injection, but also showed rapid body clearance behavior for less systemic toxicity. Furthermore, the tumor tissue targeted by the CLB-ZW800 conjugate was exposed to 808 nm NIR laser irradiation to generate photothermal energy and promote apoptotic cell death for the effective PTT of cancer. Therefore, this study provides a feasible strategy for developing bifunctional PTT agents capable of tumor-targeted imaging and phototherapy by the conjugation of small molecule drugs with the versatile zwitterionic NIR fluorophore.

Identification of an IGF2BP2-Targeted Peptide for Near-Infrared Imaging of Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies globally. Peptide-based tumor-targeted imaging is critical for ESCC imaging. In this study, we aim to identify a peptide-targeting IGF2BP2 that specifically binds to human ESCC for near-infrared imaging of esophageal cancer. Applying phage display techniques, we identified a peptide target for IGF2BP2 which was confirmed to be highly expressed in ESCC cell lines or tumor tissue and may serve as an imaging target for ESCC. We conjugated the peptide to the NIRF group, Cy5, and further evaluated the targeting efficacy of the probe at a cellular level and in animal tumor models. The Cy5 conjugated peptide (P12-Cy5) showed a high binding affinity to human ESCC cells in vitro. In vivo, optical imaging also validated the tumor-targeting ability of P12-Cy5 in KYSE-30-bearing subcutaneous ESCC tumor models. Furthermore, the results of biodistribution showed a significantly higher fluorescence intensity in tumors compared to scrambled peptide, which is consistent with in vivo observations. In summary, an IGF2BP2-targeted peptide was successfully identified. In vitro and in vivo experiments confirmed that P12-Cy5 has high affinity, specificity and tumor-targeting properties. Thus, P12-Cy5 is a prospective NIR probe for the imaging of ESCC.

Surface-Active Plasma-Polymerized Nanoparticles for Multifunctional Diagnostic, Targeting, and Therapeutic Probes

Surface-functionalized polymeric nanoparticles have advanced the field of nanomedicine as promising constructs for targeted delivery of molecular cargo as well as diagnostics and therapeutics. Conventionally, the functionalization of polymeric nanoparticles incorporates tedious wet chemical methods that require complex, multistep protocols. Surface-active plasma-polymerized nanoparticles (PPNs) produced by a dry, low-pressure plasma process can be easily functionalized with multiple ligands in a simple step. However, plasma polymerization remains limited by the challenge of efficient collection of PPNs from low-pressure plasma reactors. Here, we demonstrate a simple method to overcome this limitation by delaying the inflow of the polymer-forming precursor gas, acetylene, into a nitrogen and argon plasma discharge. We provide evidence that this cutting-edge development in the plasma polymerization method drastically enhances the collection yield of nanoparticles by 2.5-fold, compared to the simultaneous inflow of the gases. COMSOL Multiphysics simulations support our experimental data and provide insights into the role of pressure gradients in regulating the forces controlling the collection of the particles. Surface characterization data revealed that changing the sequence of the precursor gas inflow had no significant effect on the physicochemical properties of the nanoparticles, as critically important for theranostic applications. A model, green fluorescent protein, was successfully conjugated to the surface of the PPNs via a reagent-free, one-step incubation process that immobilized the biomolecule while retaining its biological activity. Cytotoxicity of the particles was assessed by a lactate dehydrogenase (LDH) assay at concentrations of up to 5 × 105 nanoparticles per cell. Despite their high concentrations, the nanoparticles were remarkably well tolerated by the cells, demonstrating their superb potential for in vivo cellular uptake. This study advances previous research on plasma-polymerized nanoparticles, introducing a low-waste synthesis method that achieves higher yields. This sustainable technology has important implications for the production of multifunctional nanoparticles for drug delivery, tumor targeting, and medical imaging.

DNA Supramolecular Assembly on Micro/Nanointerfaces for Bioanalysis.

Facing increasing demand for precision medicine, materials chemistry systems for bioanalysis with accurate molecular design, controllable structure, and adjustable biological activity are required. As a genetic biomacromolecule, deoxyribonucleic acid (DNA) is created via precise, efficient, and mild processes in life systems and can in turn precisely regulate life activities. From the perspective of materials chemistry, DNA possesses the characteristics of sequence programmability and can be endowed with customized functions by the rational design of sequences. In recent years, DNA has been considered to be a potential biomaterial for analysis and has been applied in the fields of bioseparation, biosensing, and detection imaging. To further improve the precision of bioanalysis, the supramolecular assembly of DNA on micro/nanointerfaces is an effective strategy to concentrate functional DNA modules, and thus the functions of DNA molecules for bioanalysis can be enriched and enhanced. Moreover, the new modes of DNA supramolecular assembly on micro/nanointerfaces enable the integration of DNA with the introduced components, breaking the restriction of limited functions of DNA materials and achieving more precise regulation and manipulation in bioanalysis. In this Account, we summarize our recent work on DNA supramolecular assembly on micro/nanointerfaces for bioanalysis from two main aspects. In the first part, we describe DNA supramolecular assembly on the interfaces of microscale living cells. The synthesis strategy of DNA is based on rolling-circle amplification (RCA), which generates ultralong DNA strands according to circular DNA templates. The templates can be designed with complementary sequences of functional modules such as aptamers, which allow DNA to specifically bind with cellular interfaces and achieve efficient cell separation. In the second part, we describe DNA supramolecular assembly on the interfaces of nanoscale particles. DNA sequences are designed with functional modules such as targeting, drug loading, and gene expression and then are assembled on interfaces of particles including upconversion nanoparticles (UCNPs), gold nanoparticles (AuNPs), and magnetic nanoparticle (MNPs). The integration of DNA with these functional particles achieves cell manipulation, targeted tumor imaging, and cellular regulation. The processes of interfacial assembly are well controlled, and the functions of the obtained bioanalytical materials can be flexibly regulated. We envision that the work on DNA supramolecular assembly on micro/nanointerfaces will be a typical paradigm for the construction of more bioanalytical materials, which we hope will facilitate the development of precision medicine.

Aminophosphate precursors for the synthesis of near-unity emitting InP quantum dots and their application in liver cancer diagnosis.

InP quantum dots (QDs) are a promising and environment-friendly alternative to Cd-based QDs for in vitro diagnostics and bioimaging applications. However, their poor fluorescence and stability severely limit their biological applications. Herein, we synthesize bright (∼100%) and stable InP-based core/shell QDs by using cost-effective and low-toxic phosphorus source, and then aqueous InP QDs are prepared with quantum yield over 80% by shell engineering. The immunoassay of alpha-fetoprotein can be detected in the widest analytical range of 1-1000 ng ml-1 and the limit of detection of 0.58ngml-1 by using those InP QDs-based fluorescent probes, making it the best-performing heavy metal-free detection reported so far, comparable to state-of-the-art Cd-QDs-based probes. Furthermore, the high-quality aqueous InP QDs exhibit excellent performance in specific labeling of liver cancer cells and in vivo tumor-targeted imaging of live mice. Overall, the present work demonstrates the great potential of novel high-quality Cd-free InP QDs in cancer diagnosis and image-guided surgery.

Multimodal Magnetic Resonance and Photoacoustic Imaging of Tumor-Specific Enzyme-Responsive Hybrid Nanoparticles for Oxygen Modulation.

Multimodal imaging contrast agents for cancer that can not only perform diagnostic functions but also serve as tumor microenvironment-responsive biomaterials are encouraging. In this study, we report the design and fabrication of a novel enzyme-responsive T1 magnetic resonance imaging (MRI) contrast agent that can modulate oxygen in the tumor microenvironment via the catalytic conversion of H2O2 to O2. The T1 contrast agent is a core-shell nanoparticle that consists of manganese oxide and hyaluronic acid (HA)-conjugated mesoporous silica nanoparticle (HA-MnO@MSN). The salient features of the nanoparticle developed in this study are as follows: 1) HA serves as a targeting ligand for CD44-expressing cancer cells; 2) HA allows controlled access of water molecules to the MnO core via the digestion of enzyme hyaluronidase; 3) the generation of O2 bubbles in the tumor by consuming H2O2; and 4) the capability to increase the oxygen tension in the tumor. The r 1 relaxivity of HA-MnO@MSN was measured to be 1.29 mM-1s-1 at a magnetic field strength of 9.4 T. In vitro results demonstrated the ability of continuous oxygen evolution by HA-MnO@MSN. After intratumoral administration of HA-MnO@MSN to an HCT116 xenograft mouse model, T1 weighted MRI contrast was observed after 5h postinjection and retained up to 48h. In addition, in vivo photoacoustic imaging of HA-MnO@MSN demonstrated an increase in the tumor oxygen saturation over time after i. t. administration. Thus, the core-shell nanoparticles developed in this study could be helpful in tumor-targeted T1 MR imaging and oxygen modulation.

Matrix metalloproteinase-directed precise targeting and smart drug delivery of biodegradable gold nanodandelions as CT imaging guided anticancer therapy

Systemic adverse effects and poor accumulation at tumor sites constitute important limitations of current chemotherapy in the battle against the majority of cancers. Even though utilization of nanoparticle technology is the preferred treatment modality for improving drug delivery efficiency, achieving controlled drug release and image-guided therapy still pose challenges. In this paper, we developed a tumor microenvironment-responsive gold nanodandelions encapsulating doxorubicin (GNDs@gelatin/DOX) for tumor-targeted imaging and drug delivery. High surface-area GNDs were prepared through a gelatin-mediated process which showed great DOX-loading efficiency. Specifically, GNDs@gelatin/DOX is cleavable by gelatinase (e.g., matrix metalloproteinases −2 and −9) to release the cancer therapeutic agent and aggregate in tissues where these enzymes are upregulated. We demonstrate that GNDs@gelatin/DOX accumulated preferentially in matrix metalloproteinases-2/-9 (MMP-2/-9) overexpressed tumor after intravenous injection, which is useful for computed tomography (CT) imaging-guided chemotherapeutics. Intriguingly, GNDs@gelatin/DOX exhibited the capacity to control and prolong Dox release induced suppression of tumor growth and less cardiotoxicity compared with conventional doxorubicin. In addition, our results show that the alternation of tissue inhibitors of metalloproteinases (TIMP) can attenuate MMP activity, and thus reduce the sensitivity of cancer cells to chemotherapeutics. It is noteworthy that in vivo CT imaging and subsequent inductively coupled plasma-mass spectroscopy (ICP-MS) of harvested tissues revealed that GNDs was found to transport into the gastrointestinal tract and substantial elimination from the mice with prolonged time. In aggregate, GNDs@gelatin/DOX is a highly promising chemotheranostic agent for clinical translation.