Sensitive CTC analysis and dual-mode MRI/FL diagnosis based on a magnetic core-shell aptasensor.

Synergizing the sensitive circulating tumor cell (CTC) capture, detection, release and the specific magnetic resonance/fluorescence (MR/FL) imaging for accurate cancer diagnosis is of great importance for cancer treatment. Herein, EcoR1-responsive complementary pairing of two ssDNA with a fluorescent P0 aptamer, which can specifically bind with the overexpressed MUC1 protein on cancer cells, was covalently modified to SiO2@C-coated magnetic nanoparticles for preparing a special nanoparticle-mediated FL turn-on aptasensor (FSC-D-P0). This aptasensor can selectively capture/enrich CTC and thus achieve sensitive CTC detection/imaging in even the blood due to its stable targeting, unique magnetic properties and the regulated interactions between the quencher and the fluorescent groups. Meanwhile, FSC-D-P0 can release the captured CTC for further downstream analysis upon the EcoR1 enzyme-triggered cleavage of the double-stranded DNA (dsDNA). Most importantly, this aptasensor can distinctly avoid false positivity of MRI via multiple targeting mechanisms. Thus, the sensitive CTC capture, detection, release and accurate MR/FL imaging were synergistically combined into a single platform with good biocompatibility, promising a robust pattern for clinical tumor diagnosis in vitro and in vivo.

A Space-Time Conversion Vehicle for Programmed Multi-Drugs Delivery into Pancreatic Tumor to Overcome Matrix and Reflux Barriers.

The numerous biological barriers, which limit pharmacotherapy of pancreatic carcinoma, including inadequate drug accumulation in the tumor environment, a dense extracellular matrix (ECM) and efficient drug-efflux mechanisms, illustrate the requirement of multifunctional delivery systems to overcome the individual barriers at the right place at the right time. Herein, a space-time conversion vehicle based on covalent organic framework (COF)-coated mesoporous silica nanospheres (MSN) with a sandwiched polyethyleneimine (PEI) layer (MPCP), is designed. The space-specific drugs-loaded vehicle (MG PP CL P) is obtained by separately incorporating a chemotherapeutic agent (gemcitabine, G) into the MSN core, a P glycoprotein inhibitor (LY 335979, P) into the PEI layer, and an extracellular matrix disruptor (losartan, L) into the COF shell. Thereafter, a programmed drug delivery is achieved via the ordered degradation from COF shell to MSN core. Sequential release of the individual drugs, synergized with a change of nanoparticle surface charge, contribute to an obvious extracellular matrix distraction, distinct drug efflux inhibition, and consequently enhance chemotherapeutic outcomes in pancreatic carcinoma. This MPCP-based vehicle design suggests a robust space-time conversion strategy to achieve programmed multi-drugs delivery and represents a new avenue to the treatment of pancreatic carcinoma by overcoming extracellular matrix and drug reflux barriers.

Magnetic covalent organic framework nanospheres-based miRNA biosensor for sensitive glioma detection.

Sensitive detection and accurate diagnosis/prognosis of glioma remain urgent challenges. Herein, dispersed magnetic covalent organic framework nanospheres (MCOF) with uniformed Fe3O4 nano-assembly as cores and high-crystalline COF as shells were prepared by monomer-mediated in-situ interface growth strategy. Based on the unique interaction between MCOF and hairpin DNA, a fluorescent signal amplified miRNA biosensor was constructed. It could realize the sensitive detection of miRNA-182 in different matrixes, where the detection limit, linearity range and determination coefficient (R2) in real blood samples reached 20 fM, 0.1 pM-10 pM and 0.991, respectively. Also, it possessed good stability and precision as observed from the low intra-day/inter-day RSD and high extraction recovery. As a result, it could quantify miRNA-182 in serum of glioma patients, the concentration of which was significantly higher than that of healthy people and obviously decreased after surgery. Finally, a proof-of-concept capillary chip system using this biosensor was proposed to realize the visualized detection of miRNA-182 in microsample. These findings suggest a robust way for sensitive detection and accurate diagnosis/prognosis of glioma.

Tumor-Selective Biodegradation-Regulated Photothermal H2 S Donor for Redox Dyshomeostasis- and Glycolysis Disorder-Enhanced Theranostics.

H2 S-mediated tumor therapy has received great attention due to its unique physiological activity and synergistical enhancement, but suffers from limited H2 S donors with promised biosafety to regulate the H2 S delivery and subsequently the elusive pathway to augment the combined therapy. Herein, a PEGylated porous molybdenum disulfide nanoflower (MSP) with abundant defects is facilely synthesized for tumor-targeted theranostics. MSP possesses good water-dispersity and high photothermal ability, which is used for photoacoustic imaging and photothermal therapy. Interestingly, MSP is selectively degraded upon exposure to superfluous glutathione (GSH) within tumor cells, the mechanism of which is investigated, as a reduction-coordination reaction. This special degradation induces redox dyshomeostasis via GSH depletion for reactive oxygen species-accumulated chemodynamic therapy. Meanwhile, the selective biodegradation of MSP regulates a sustained H2 S release within tumor and achieves a targeted H2 S gas therapy via enhancing the glycolysis to acidify the tumor cells (glycolysis disorder). Synergistically, these performances are further enhanced via near-infrared photothermal heating, where excellent therapeutic outcomes with good biosafety are accomplished in vitro and in vivo. These characteristics, together with the unique biodegradation and no obvious side-effects of the nanoparticles, suggest a potential therapeutic strategy for precise tumor treatments.

Tumor-Targeted Fluorescence Imaging and Mechanisms of Tumor Cell-Derived Carbon Nanodots.

An ideal cancer diagnostic probe should possess precise tumor-targeted accumulation with negligible sojourn in normal tissues. Herein, tumor cell-derived carbon nanodots (C-CNDU87 and C-CNDHepG2) about 3~7 nm were prepared by a solvothermal method with stable fluorescence and negligible cytotoxicity. More interestingly, due to the differences in gene expression of cancers, C-CND structurally mimicked the corresponding precursors during carbonization in which carbon nanodots were functionalized with α-amino and carboxyl groups with different densities on their edges. With inherent homology and homing effect, C-CND were highly enriched in precursor tumor tissues. Mechanistic studies showed that under the mediation of the original configuration of α-amino and carboxyl groups, C-CND specifically bound to the large neutral amino acid transporter 1 (LAT1, overexpressed in cancer cells), achieving specific tumor fluorescence imaging. This work provided a new vision about tumor cell architecture-mimicked carbon nanodots for tumor-targeted fluorescence imaging.

Mitochondrial Dysfunction and Antioxidation Dyshomeostasis-Enhanced Tumor Starvation Synergistic Chemotherapy Achieved using a Metal-Organic Framework-Based Nano-Enzyme Reactor.

Exploiting zeolitic imidazolate framework (ZIF)-based nanoparticles to synergistically enhance starvation-combined chemotherapy strategies remains an urgent demand. Herein, glucose oxidase (GOX) and doxorubicin (DOX) were facilely incorporated into ZIFs for starvation-combined chemotherapy. The as-prepared DOX/GOX-loaded ZIF (DGZ) exhibited uniform size with good dispersity, effective protection of the GOX activity, and stable delivery of the drugs into tumor. Correspondingly, it could achieve the glucose- and pH-responsive degradation and thus the controllable drug release. As a result, the acidification of glucose accompanied with reactive oxygen species (ROS) production was observed for the starvation-enhanced chemotherapy and the improved degradation. Most importantly, adjustable Zn2+ release was achieved with the biodegradation of DGZ, which thus contributed to an augmented therapeutic outcome via the Zn2+-induced mitochondrial dysfunction and antioxidation dyshomeostasis. These findings, synergized with the enhancement of starvation-combined chemotherapy by inhibiting the mitochondrial energy metabolism and boosting the ROS accumulation using pristine ZIF-based nanoparticles, provide a new insight into the metal-organic framework-based nanomedicine for further cancer treatments.

A Novel Chemiluminescence Probe for Sensitive Detection of Fibroblast Activation Protein-Alpha In Vitro and in Living Systems.

Fibroblast activation protein-alpha (FAPα) is a key modulator of the microenvironment in multiple pathologies and is becoming the next pan-cancer target for cancer diagnostics and therapeutics. Chemiluminescence (CL) luminophores are considered as one of the most sensitive families of probes for detection and imaging applications due to their high signal-to-noise ratio. Until now, however, no such effective CL probe was reported for FAPα detection. Herein, we developed a novel CL probe for the detection of endogenous FAPα activity by incorporating FAPα-specific dipeptide substrates (glycine-proline) to the improved Schaap's adamantylidene-dioxetane. In this manner, we designed three CL probes (CFCL, BFCL, and QFCL) with the dipeptide substrate blocked by N-terminal benzyloxycarbonyl, N-tert-butoxycarbonyl or N-quinoline-4-carboxylic acid, respectively, which was used as the masking group to restrain the chemiexcitation energy. Probe CFCL exhibited the optimal specificity for the discrimination of FAPα from dipeptidase IV and prolyl oligopeptidase, which was elucidated by molecular docking simulation. Upon FAPα cleavage, CFCL was turned on for the highly selective and sensitive detection of FAPα with a limit of detection of 0.785 ng/mL. Furthermore, the ability of CFCL to image FAPα was effectively demonstrated in vitro, including various biological samples (plasma and tissue preparations), and in living systems (tumor cells and tumor-bearing mice). Furthermore, this newly established probe could be easily extended to evaluate FAPα inhibitors. Overall, we anticipate that probe CFCL will offer a facile and cost-effective alternative in the early detection of pathologies, individual tailoring of drug therapy, and drug screening.

Versatile hollow COF nanospheres via manipulating transferrin corona for precise glioma-targeted drug delivery.

Covalent organic framework (COF) nanoparticles for interference-free targeted drug delivery to glioma remains in its infancy. Herein, hollow COF nanospheres with high crystallinity and uniformed sizes were facilely prepared via heterogeneous nucleation-growth. The prepared COF had large surface area/pore volume and exhibited appropriate degradation behavior under acid environment, where therefore doxorubicin was effectively encapsulated and exhibited a pH-sensitive release. Most charmingly, T10 peptide that has high affinity with transferrin (Tf), was conjugated to endow the hollow COF interesting properties to specifically absorb Tf in vivo as Tf corona. For the first time, multifunctional hollow COF nanospheres (the better one named DCPT-2) were successfully synthesized to achieve interference-free cascade-targeting glioma drug delivery across the blood-brain barrier. Treatment with DCPT-2 brought an improved therapeutic outcome with significantly prolonged median survival time and low side effects. This work promised not only a potential protein corona-mediated COF-based drug delivery platform with good biocompatibility for effective and precise brain tumor therapy, but also an endogenous protein corona-mediated targeting strategy for general cancer therapy.

Multimodal theranostics augmented by transmembrane polymer-sealed nano-enzymatic porous MoS2 nanoflowers.

Developing an all-in-one multimodal theranostic platform that can synergistically integrate sensitive photoacoustic (PA) imaging, enhanced photothermal therapy (PTT) and photodynamic therapy (PDT) as well as the nano-enzyme activated chemodynamic therapy (CDT) presents a great challenge for the current nanomedicine design. Herein, a simple hydrothermal method was used to prepare porous molybdenum disulfide (MoS2) nanoflowers. These nanoflowers were assembled by three dimensional (3D)-stacked MoS2 nanosheets with plentiful pores and large surfaces, which thus exhibited enhanced photothermal conversion via light trapping and peroxidase (POD)-like activity via active defects exposure. Consequently, this 3D-MoS2 nanostructure could be well-sealed by polyethylene glycol-polyethylenimine polymer modified with nucleolar translocation signal sequence of the LIM Kinase 2 protein (LNP) via strong electrostatic interaction, which not only benefited to stably deliver anticancer drug doxorubicin (DOX) into the tumor cells for pH/NIR-responsive chemotherapy, but also provided strong photoacoustic, photothermal performances and stimulated generation of reactive oxygen species (ROS) for imaging-guided PTT/PDT/CDT combined therapy. This work promised a simple all-in-one multimodal theranostic platform to augment the potential antitumoral therapeutic outcomes.

Multifunctional mesoporous black phosphorus-based nanosheet for enhanced tumor-targeted combined therapy with biodegradation-mediated metastasis inhibition.

Functionalizing black phosphorus nanosheet (BP) with efficient drug loading and endowing mesoporous silica nanomaterials with appropriate biodegradation for controllable tumor-targeted chemo-photothermal therapy are still urgent challenges. Herein, an ordered mesoporous silica-sandwiched black phosphorus nanosheet (BP@MS) with the vertical pore coating was prepared. The strategy could not only enhance the BP's dispersity and improve its doxorubicin (DOX)-loading efficiency, but also facilitate post-modification such as PEGylation and conjugation of targeting ligand, TKD peptide, yielding BSPT. A DOX-loaded BSPT-based system (BSPTD) showed heat-stimulative, pH-responsive, and sustained release manners. In vitro and in vivo results demonstrated that BSPTD had a delayed but finally complete degradation in physiological medium, contributing to an optimal therapeutic window and good biosafety. As a result, BSPTD can achieve an effective chemo-photothermal synergistic targeted therapy of tumor. Moreover, treating by BSPTD was found to be capable of remarkably inhibiting the lung metastasis of tumor, attributing to the photothermal degradation-facilitated secondary drug delivery. Our study provided a robust strategy to functionalize BP nanosheet and biodegrade the mesoporous silica for extended biomedical applications.

Biodegradable Mesoporous Silica Achieved via Carbon Nanodots-Incorporated Framework Swelling for Debris-Mediated Photothermal Synergistic Immunotherapy.

Incorporating carbon nanodots (CDs) into mesoporous silica framework for extensive biomedicine, especially for the desirable cancer immunotherapy, is considered to be an unexplored challenge. Herein, a hydrogen bond/electrostatic-assisted co-assembly strategy was smartly exploited to uniformly incorporate polymer-coated CDs into ordered framework of mesoporous silica nanoparticles (CD@MSNs). The obtained CD@MSN was not only biodegradable via the framework-incorporated CD-induced swelling but also capable of gathering dispersive CDs with enhanced photothermal effect and elevated targeting accumulation, which therefore can achieve photothermal imaging-guided photothermal therapy (PTT) in vitro and in vivo. Interestingly, benefiting from the biodegraded debris, it was found that CD@MSN-mediated PTT can synergistically achieve immune-mediated inhibition of tumor metastasis via stimulating the proliferation and activation of natural killer cells and macrophages with simultaneously up-regulating the secretion of corresponding cytokines (IFN-γ and Granzyme B). This work proposed an unusual synthesis of biodegradable mesoporous silica and provided an innovative insight into the biodegradable nanoparticles-associated anticancer immunity.

Effect of Soluplus on the supersaturation and absorption of tacrolimus formulated as inclusion complex with dimethyl-ß-cyclodextrin.

The application of tacrolimus (FK506) is hampered by its poor solubility and dissolution, which can be promoted by the use of inclusion complex. However, in supersaturated environment, crystallization of the drug inclusion complex may occur, leading to reduced absorption in vivo. In this study, Soluplus, an amphiphilic copolymer of polyvinyl caprolactam, polyvinyl acetate and polyethylene glycol, was used to improve the supersaturated stability and absorption of FK506. Using dimethyl-ß-cyclodextrin (DM-ß-CD), the inclusion complex (FK506-CD) was prepared, which showed favorable dissolution profiles. But in supersaturated condition, the drug concentration was rapidly decreased, with 10.64 ± 0.69 µg/ml of FK506 at 12 h. Ternary complex (FK506-SCD) containing Soluplus contributed steadier drug concentration. The FK506-SCD with 1.2% Soluplus best promoted the supersaturated stability of the inclusion complex, with 62.90 ± 3.34 µg/ml of FK506 at 12 h. Soluplus also reduced the crystallization and degradation of FK506 in the stress test. In the single-pass intestinal perfusion test, the absorption of FK506 in the ileum and colon was significantly increased. Pharmacokinetic results showed that the bioavailability of FK506-SCD was 2.34-fold that of FK506-CD. Our data suggested that Soluplus had an excellent capability in improving the supersaturated stability and in vivo absorption of FK506 inclusion complex.

Preparation and comparison of tacrolimus-loaded solid dispersion and self-microemulsifying drug delivery system by in vitro/in vivo evaluation.

This study aimed to compare the dissolution and the intestinal absorption of tacrolimus in self-microemulsifying drug delivery system (SMEDDS) and solid dispersion (SD). Poloxamer 188 SD was prepared by the combination of the solvent evaporation method and the freeze drying method. Hydroxypropyl methylcellulose (HPMC) SD was prepared by the solvent evaporation method combined with the vacuum drying method. The formation of SD was confirmed by SEM images which showed new solid phases. The SMEDDS was composed of oil (Labrafil M1944 CS 28%), surfactant (Cremophor EL 48%) and co-surfactant (Transcutol P 24%). The self microemulsion formed by the SMEDDS upon aqueous media had spherical droplets with a hydrodynamic size of 46.0±3.2nm. The dissolution of tacrolimus from SD and SMEDDS was performed in sink and non-sink conditions with various pH. As revealed by the DSC and FT-IR, the tacrolimus was molecularly or amorphously dispersed in the SMEDDS and SD. The in vivo intestinal absorption study in rats showed that both SMEDDS and SD improved the absorption of tacrolimus over the raw tacrolimus while the SMEDDS exhibited lower absorption rate constant (Ka) and apparent permeability coefficients (Papp) than the SD. The self-prepared SD with poloxamer 188 or HPMC had comparable intestinal absorption as compared with Prograf®. The tacrolimus-loaded SMEDDS and SD would be further compared by in vivo pharmacokinetic study.