Multifunctional Nanoprobes Research Articles

Mesoporous carbon nanospheres featured multifunctional fluorescent nanoprobe: Simultaneous activation and tracing of caspase-3 involved cell apoptosis

Caspase-3 is considered to be a key regulator of cell apoptosis. Simultaneous activation and detection of caspase-3 in living cells is therefore highly important for precise cancer therapy and therapeutic efficacy evaluation but it is still a key challenge. Herein, a novel and simple multifunctional peptide-tailored mesoporous carbon nanospheres (MCN) has been developed for simultaneous cancer photothermal therapy (PTT) and real-time imaging of caspase-3 induced cell apoptosis. The nanoprobe was facilely prepared by modifying fluorescein isothiocyanate (FITC)-tagged peptide specific to caspase-3 on the surface of MCN. The signal switch relies on the unique quenching effect of MCN on the fluorescently labeled peptide, cleavage of the peptide by activated caspase-3 will result in a significant fluorescence lighting-up for sensitive caspase-3 analysis. The detection limit of 0.4 pg·mL−1 with a linear range from 10 pg·mL−1 to 1 ng·mL−1 was achieved. Owing to the intrinsic properties of MCN, the nanoprobe not only can be served as photothermal transducer to activate caspase-3, but also can simultaneously real-time monitoring caspase-3 activity in living cells with high specificity. This work demonstrates a smart molecular imaging strategy for cell apoptosis, which also provides a potential new platform for apoptosis-related diagnosis and precise cancer therapeutic applications.

Novel Non-Invasive Diagnosis of Bladder Cancer in Urine Based on Multifunctional Nanoparticles.

Objectives: Tumor cells were reported to have perpetual negative surface charges due to elevated glycolysis, and multifunctional nanoprobes (Fe3O4@SiO2, mNPs) could attach onto tumor cells via opposite surface charges. We thus evaluated whether mixing mNPs with urine could improve the sensitivity of urine cytology test (UCT). Methods: We developed a novel UCT method by mixing urine with mNPs (Nano-cytology) to harvest more tumor cells during UCT procedures. The same voided urine sample was divided equally for the Nano-cytology and UCT assay, and evaluated by cytopathologists in a blinded way. The accuracy of UCT, Nano-cytology, and the combination of the two approaches (Nano-UCT) for detecting bladder cancer were determined. Results: Urine samples were prospectively collected from 102 bladder cancer patients and 49 non-cancer participants from June 2020 to February 2021 in Changhai Hospital. Overall sensitivity of the Nano-cytology assay was significantly higher than that of the UCT assay (82.4 vs. 59.8%, p < .01). Sensitivity for low- and high-grade tumors was 79.1% and 39.5% (p < .01) and 84.7% and 74.6% (p = .25) for Nano-cytology and UCT, respectively. Specificity of Nano-cytology was slightly lower than that of UCT (89.8% vs. 100%, p = .022), which is mainly caused by severe urinary tract infection. In addition, Nano-UCT showed increased sensitivity with 90.2% for overall patients, and 83.7% and 94.9% for low- and high-grade tumor, respectively. Conclusion: The Nano-cytology assay had a significantly improved sensitivity compared with UCT for detecting bladder cancer patients. It represents a promising tool for diagnosis of bladder cancer in clinical practice.

Multifunctional Cellular Targeting, Molecular Delivery, and Imaging by Integrated Mesoporous-Silica with Optical Nanocrescent Antenna: MONA.

Multifunctional nanoprobes have attracted significant attention in a wide range of disciplines such as nanomedicine, precision medicine, and cancer diagnosis and treatment. However, integrating multifunctional ability in a nanoscale structure to precisely target, image, and deliver with cellular spatial/temporal resolution is still challenging in cellulo applications. This is because the development of such high-precision resolution needs to be carried out without labeling, photobleaching, and structurally segregating live cells. In this study, we present an integrated nanostructure of a mesoporous-silica nanosphere with an optical nanocrescent antenna (MONA) for multifunctional cellular targeting, drug delivery, and molecular imaging with spatiotemporal resolution. MONA comprises a systematically constructed Au nanocrescent (AuNC) antenna as a nanosensor and optical switch on a mesoporous-silica nanosphere as a cargo to molecular delivery. MONA made of antiepithelial cell adhesion molecules (anti-EpCAM)-conjugated AuNC facilitates the specific targeting of breast cancer cells, resulting in a highly focused photothermal gradient that functions as a molecular emitter. This light-driven molecular, doxorubicin (DOX) delivery function allows rapid apoptosis of breast cancer cells. Since MONA permits the tracking of quantum biological electron-transfer processes, in addition to its role as an on-demand optical switch, it enables the monitoring of the dynamic behavior of cellular cytochrome c pivoting cell apoptosis in response to the DOX delivery. Owing to the integrated functions of molecular actuation and direct sensing at the precisely targeted spot afforded by MONA, we anticipate that this multifunctional optical nanoantenna structure will have an impact in the fields of nanomedicine, cancer theranostics, and basic life sciences.

One-dimensional nanohybrids based on cellulose nanocrystals and their SERS performance

Controllable and uniform loading of gold nanospheres (AuNSs) on cellulose nanocrystal (CNC) were first achieved by electrostatic adsorption self-assembly. By adjusting the size, Zeta potential, and the loading ratio of AuNSs and CNC, the particle spacing of AuNSs on CNC surface was successfully regulated. This strategy provides an easy and efficient approach to construct one dimensional (1D) "hot spots”, which is a key to improve the performance of surface enhanced Raman scattering spectroscopy (SERS). When used as SERS probe, the nanohybrid of CNC@AuNSs is able to detect Rhodamine 6G at the low concentration of 5 × 10−8 g/L. Because AuNSs are fixed on CNC to form stable “hot spots”, the SERS reproducibility of CNC@AuNSs is significantly improved compared to that of colloidal gold nanoparticles, which generally form unstable “hot spots” via irreversible aggregation. This type of multifunctional nanoprobe based on CNC has potential applications in the field of sensing detection.

Versatile scaffold applications based on MoS2 quantum dots for imaging mitochondrial pH in living cells

Sensitive and accurate detection and imaging of mitochondrial pH have become significant methods in biological and biomedical research to elucidate the biological functions of mitochondria. Herein, a mitochondria-targeted ratiometric fluorescent nanoprobe was developed to image mitochondrial pH in living cells. This nanoprobe was prepared by covalently linking a mitochondria-targeted ligand (triphenylphosphonium, TPP) and a pH recognition fluorescent indicator (rhodamine, RhB) onto the surface of MoS2 quantum dots (QDs). In this multifunctional fluorescent nanoprobe, MoS2 QDs serve not only as nanocarrier for the targeting ligand and pH fluorescent indicator, but also as a fluorescent reference for the ratiometric signal. Indeed, the fluorescence intensity of the MoS2 QDs is highly resistant to increasing proton concentrations, while that of RhB is sensitive to pH. Ratiometric detection of pH was carried out by comparing the pH-sensitive fluorescence of the RhB-based group with the pH-resistant fluorescence of MoS2 QDs. After uptake in living cells, the nanoprobe could stain mitochondria specifically, and allowed to image and monitor pH in mitochondria in a satisfactory manner.

Application of "smart" multifunctional nanoprobes in tumor diagnosis and treatment.

Cancer is one of the major diseases that pose a threat to human health and life, especially because it is difficult to diagnose and cure, and recurs easily. In recent years, the development of nanotechnology has provided researchers with new tools for cancer treatment. In particular, nanoprobes that facilitate integrated diagnosis and treatment, high-resolution imaging, and accurate tumor targeting provide new avenues for the early detection and treatment of cancer. This review focuses on the preparations and applications of two kinds of "smart" multifunctional nanoprobes: "Off-On" nanoprobes and "Charge-Reversal" nanoprobes. This review also briefly discusses their mechanisms of action, as they could provide new ideas for the further development of this field.

A multifunctional nanoprobe for real-time SERS monitoring of invasion ability affected by photodynamic therapy.

A multifunctional RhB-PLGM@CN nanoprobe was created, in which g-C3N4 played dual pivotal functions in photodynamic therapy (PDT) and monitoring of invasion-related MMP-9 by surface-enhanced Raman spectroscopy. Significantly, using this probe, PDT was found to inhibit the cell invasion in a glioblastoma multiforme cell line model by down regulation of MMP-9.

A multifunctional nanoprobe based on europium(iii) complex–Fe3O4 nanoparticles for bimodal time-gated luminescence/magnetic resonance imaging of cancer cells in vitro and in vivo

A multifunctional nanoprobe for tumor-targeting time-gated luminescence and magnetic resonance imaging in vitro and in vivo.

Multifunctional nanoprobes combined with radiotherapy and hypoxia-activated therapy synergistically improve antitumor efficacy.

The presence of hypoxia in tumors is characteristic of most solid tumors and it promotes not only tumor angiogenesis but also tumor cell invasion and metastasis. It also results in resistance of tumor tissue to radiation, leading to poor outcomes of tumor radiotherapy. Therefore, to address this conundrum, highly selective gold nanoclusters were prepared as fluorescent imaging agents and radiosensitizers and then loaded with tumor hypoxia-activated prodrugs to prepare nanoprobes which synergistically improved the anti-tumor efficacy by combining radiotherapy and hypoxia-activated therapy. The designed nanoprobes have ultra-small size, high selectivity for integrin αvβ3 receptor-positive tumor cells and tumor neovascular endothelial cells, and excellent fluorescence imaging performance. The experimental procedures were carried out in vitro and in vivo to demonstrate that the developed nanoprobes have a high level of biocompatibility, efficient radiosensitization effect, and anti-tumor efficacy at cell and tissue levels. The combined application of radiotherapy and hypoxia-activated therapy can overcome the radiation resistance caused by tumor hypoxia, compensate for the limitations of single radiotherapy, inhibit tumor growth, improve the efficacy of tumor radiotherapy, and provide new possibilities for the development of more precise and effective treatment strategies.

Multifunctional Nanoprobe for Real-Time In Vivo Monitoring of T Cell Activation

Multifunctional Nanoprobe for Real-Time In Vivo Monitoring of T Cell Activation

Multimodal Imaging Technology Effectively Monitors HER2 Expression in Tumors Using Trastuzumab-Coupled Organic Nanoparticles in Patient-Derived Xenograft Mice Models.

Trastuzumab is a monoclonal antibody targeting human epidermal growth factor 2 (HER2), which has been successfully used in the treatment of patients with breast cancer and gastric cancer; however, problems concerning its cardiotoxicity, drug resistance, and unpredictable efficacy still remain. Herein, we constructed novel organic dopamine–melanin nanoparticles (dMNs) as a carrier and then surface-loaded them with trastuzumab to construct a multifunctional nanoprobe named Her-PEG-dMNPs. We used micro-PET/CT and PET/MRI multimodality imaging to evaluate the retention effect of the nanoprobe in HER2 expression in gastric cancer patient-derived xenograft (PDX) mice models after labeling of the radionuclides 64Cu or 124I and MRI contrast agent Mn2+. The nanoprobes can specifically target the HER2-expressing SKOV-3 cells in vitro (3.61 ± 0.74 vs. 1.24 ± 0.43 for 2 h, P = 0.002). In vivo, micro-PET/CT and PET/MRI showed that the 124I-labeled nanoprobe had greater contrast and retention effect in PDX models than unloaded dMNPs as carrier (1.63 ± 0.07 vs. 0.90 ± 0.04 at 24 h, P = 0.002), a similarity found in 64Cu-labeled Her-PEG-dMNPs. Because 124I has a longer half-life and matches the pharmacokinetics of the nanoparticles, we focused on the further evaluation of 124I-Her-PEG-dMNPs. Furthermore, immunohistochemistry staining confirmed the overexpression of HER2 in the animal model. This study developed and validated novel HER2-specific multimodality imaging nanoprobes for quantifying HER2 expression in mice. Through the strong retention effect of the tumor site, it can be used for the promotion of monoclonal antibody treatment effect and process monitoring.

A Multifunctional AIE Nanoprobe as a Drug Delivery Bioimaging and Cancer Treatment System.

Of all malignant brain tumors, glioma is the deadliest and most common, with a poor prognosis. Drug therapy is considered as a promising way to stop the progression of disease and even cure tumors. However, the presence of blood brain barrier (BBB) and blood tumor barrier (BTB) limits the delivery of these therapeutic genes. In this work, an intelligent cell imaging and cancer therapy drug delivery system targeting the blood-brain barrier and the highly expressed transferrin receptors (TfR) in gliomas has been successfully constructed, and an amphiphilic polymer (PLA-PEG-T7/TPE) with aggregation-induced emission (AIE) properties has been designed and successfully synthesized. PLA-PEG-T7/TPE self-assembled polymer micelles showed significant AIE effect in aqueous solution with good biocompatibility. Therefore, it can be used for potential biological imaging applications. In addition, drug-carrying micelles showed typical behavior of regulating drug release. Inhibition of cell proliferation in vitro showed that the drug-loaded micelles had dose-dependent cytotoxicity to LN229 cells. In the in vivo anti-tumor experiment, PLA-PEG-T7/TPE/TMZ had the best therapeutic effect. These results indicated that T7 functionalized PLA-PEG was a promising platform for nasopharyngeal cancer drug combination therapy.

In vivo static and dynamic angiography of thrombosis by using multi-functional lanthanide nanoprobes

Main content : We finely tuned the core–shell NaNdF 4 @NaGdF 4 nanoparticles for in vivo static and dynamic multi-modal angiographies (i.e. NIR-II FLA/ MRA/CTA), with a focus on the dynamic NIR-II FLA evaluation of cerebral blood perfusion induced by thrombus and thrombolysis. Innovation : We fabricated a multi-functional angiographic nanoagent to combine the advantages of MRA and NIR-II FLA for noninvasive diagnosis of carotid thrombosis and evaluating cerebral blood perfusion, monitoring thrombosis and thrombolysis. We provide a new method for early diagnosis, prevention and evaluation of therapeutic effect of ischemic stroke.

Aptamer-conjugated magnetic Fe3O4@Au core-shell multifunctional nanoprobe: A three-in-one aptasensor for selective capture, sensitive SERS detection and efficient near-infrared light triggered photothermal therapy of Staphylococcus aureus

Early and accurate diagnosis of pathogenic bacteria is essential to prevent further infection from spreading and multiplying. Herein, an aptamer (Apt) biosensor based on Fe3O4@Au nanocomposites (NCs) has been proposed for capture, surface-enhanced Raman scattering (SERS) detection, and photothermal therapy (PTT) of S. aureus. Fe3O4@Au NCs become SERS substrate and photothermal agent due to superior surface plasmon properties and photothermal ability, while the aptamer immobilized on surface of Fe3O4@Au NCs acts as a capture agent. The detection limit of optimized Fe3O4@Au-Apt aptasensor for S. aureus is 25 cfu/mL, and cell capture efficiency (CCE) is as high as 68%. Moreover, our Fe3O4@Au-Apt NCs have high photothermal conversion efficiency of 39.28%, which have been proven as an excellent photothermal agent. As verified by experiments, Fe3O4@Au-Apt aptasensor is not only a promising tool to detect and photothermally inactivated S. aureus in milk samples, but also exhibits negligible cytotoxicity and good biocompatibility. This work shows a promising multifunctional nano-platform, which has great potential in specific recognition, sensitive SERS detection and PTT of S. aureus.

A Hybrid Nanogel to Preserve Lysosome Integrity for Fluorescence Imaging.

Fluorescence imaging of lysosomes provides a powerful tool to probe the lysosome physiology in living cells, yet the continuous light exposure inevitably causes lysosome damage and phototoxicity, which remains a formidable challenge. Here the long-term lysosome tracking with minimized photodamage was realized using a multifunctional nanoprobe, a platinum nanoparticle, and a quinacrine co-loaded nanogel. To construct the hybrid nanogel, cisplatin first functioned as cross-linker to withhold all components and then was reduced to a platinum nanoparticle in situ by ethanol. The platinum nanoparticle enabled a long-term quinacrine fluorescence imaging of lysosome by scavenging the light induced reactive oxygen species which could damage lysosomal membranes.

Application of multifunctional nanoprobes in tumor immunotherapy guided by medical imaging

<p indent=0mm>Immunotherapy has attracted extensive attention as an effective means for tumor treatment instead of traditional methods such as surgery, radiotherapy, and chemotherapy. The combination of immunotherapy and multifunctional nanoprobes can realize the early diagnosis and treatment of tumors. Various studies have shown that multifunctional nanoprobes can achieve multi-mode imaging and the multi-mode treatment of tumors. Meanwhile, tumor cell death induced by some nanoprobes can lead to the release of tumor antigen to promote specific immune response to tumor immunotherapy. In this paper, we review the application and development prospect of multifunctional nanoprobes for immunotherapy combined with fluorescence imaging, computed tomography imaging, and magnetic resonance imaging.

Asialoglycoprotein receptor targeted optical and magnetic resonance imaging and therapy of liver fibrosis using pullulan stabilized multi-functional iron oxide nanoprobe

Early diagnosis and therapy of liver fibrosis is of utmost importance, especially considering the increased incidence of alcoholic and non-alcoholic liver syndromes. In this work, a systematic study is reported to develop a dual function and biocompatible nanoprobe for liver specific diagnostic and therapeutic applications. A polysaccharide polymer, pullulan stabilized iron oxide nanoparticle (P-SPIONs) enabled high liver specificity via asialogycoprotein receptor mediation. Longitudinal and transverse magnetic relaxation rates of 2.15 and 146.91 mM−1 s−1 respectively and a size of 12 nm, confirmed the T2 weighted magnetic resonance imaging (MRI) efficacy of P-SPIONs. A current of 400A on 5 mg/ml of P-SPIONs raised the temperature above 50 °C, to facilitate effective hyperthermia. Finally, a NIR dye conjugation facilitated targeted dual imaging in liver fibrosis models, in vivo, with favourable histopathological results and recommends its use in early stage diagnosis using MRI and optical imaging, and subsequent therapy using hyperthermia.

Covalent Organic Framework-Derived Carbonous Nanoprobes for Cancer Cell Imaging.

Covalent organic frameworks (COFs) have emerged as promising materials for biomedical applications, but their functions remain to be explored and the potential toxicity concerns should be resolved. Herein, it is presented that carbonization significantly enhances the fluorescence quenching efficiency and aqueous stability of nanoscale COFs. The probes prepared by physisorbing dye-labeled nucleic acid recognition sequences onto the carbonized COF nanoparticles (termed C-COF) were employed for cell imaging, which could effectively light up biomarkers (survivin and TK1 mRNA) in living cells. The C-COF has enhanced photothermal conversion capacity, indicating that the probes are also promising candidates for photothermal therapy. The potential toxicity concern from the aromatic rigid building units of COFs was detoured by carbonization. Overall, carbonization is a promising strategy for developing biocompatible and multifunctional COF-derived nanoprobes for biomedical applications. This work may inspire more versatile COF-derived nanoprobes for bioanalysis and nanomedicine.

Conjugates of Ultrasmall Quantum Dots and Acridine Derivatives as Prospective Nanoprobes for Intracellular Investigations.

Designing nanoprobes in which quantum dots (QDs) are used as photoluminescent labels is an especially promising line of research due to their possible medical applications ranging from disease diagnosis to drug delivery. In spite of the significant progress made in designing such nanoprobes, the properties of their individual components, i.e., photoluminescent QDs, vectorization moieties, and pharmacological agents, still require further optimization to enhance the efficiency of diagnostic or therapeutic procedures. Here, we have developed a method of engineering compact multifunctional nanoprobes based on functional components with optimized properties: bright photoluminescence of CdSe/ZnS (core/shell) QDs, a compact and effective antitumor agent (an acridine derivative), and direct conjugation of the components via electrostatic interaction, which provides a final hydrodynamic diameter of nanoprobes smaller than 15 nm. Due to the possibility of conjugating various biomolecules with hydroxyl and carboxyl moieties to QDs, the method represents a versatile approach to the biomarker-recognizing molecule imaging of the delivery of the active substance as part of compact nanoprobes.

Aptamer-mediated synthesis of multifunctional nano-hydroxyapatite for active tumour bioimaging and treatment.

ObjectivesThe nano‐hydroxyapatite (nHAp) is widely used to develop imaging probes and drug carriers due to its excellent bioactivity and biocompatibility. However, traditional methods usually need cumbersome and stringent conditions such as high temperature and post‐modification to prepare the functionalized nHAp, which do not benefit the particles to enter cells due to the increased particle size. Herein, a biomimetic synthesis strategy was explored to achieve the AS1411‐targeted tumour dual‐model bioimaging using DNA aptamer AS1411 as a template. Then, the imaging properties and the biocompatibility of the synthesized AS‐nFAp:Gd/Tb were further investigated.Materials and methodsThe AS‐nFAp:Gd/Tb was prepared under mild conditions through a one‐pot procedure with AS1411 as a template. Besides, the anticancer drug DOX was loaded to AS‐nFAp:Gd/Tb so as to achieve the establishment of a multifunctional nano‐probe that integrated the tumour diagnosis and treatment. The AS‐nFAp:Gd/Tb was characterized by transmission electron microscopy (TEM), energy disperse X‐ray Spectroscopy (EDS) mapping, X‐ray photoelectron spectroscopy (XPS) spectrum, X‐ray diffraction (XRD), fourier‐transformed infrared (FTIR) spectroscopy, capillary electrophoresis analyses, zeta potential and particle sizes. The in vitro magnetic resonance imaging (MRI) and fluorescence imaging were performed on an MRI system and a confocal laser scanning microscope, respectively. The potential of the prepared multifunctional nHAp for a targeted tumour therapy was investigated by a CCK‐8 kit. And the animal experiments were conducted on the basis of the guidelines approved by the Animal Care and Use Committee of Sichuan University, China.ResultsIn the presence of AS1411, the as‐prepared AS‐nFAp:Gd/Tb presented a needle‐like morphology with good monodispersity and improved imaging performance. Furthermore, due to the specific binding between AS1411 and nucleolin up‐expressed in cancer cells, the AS‐nFAp:Gd/Tb possessed excellent AS1411‐targeted fluorescence and MRI imaging properties. Moreover, after loading chemotherapy drug DOX, in vitro and in vivo studies showed that DOX@AS‐nFAp:Gd/Tb could effectively deliver DOX to tumour tissues and exert a highly effective tumour inhibition without systemic toxicity compared with pure DOX.ConclusionsThe results indicated that the prepared multifunctional nHAp synthesized by a novel biomimetic strategy had outstanding capabilities of recognition and treatment for the tumour and had good biocompatibility; hence, it might have a potential clinical application in the future.