Activated Carbon nanoparticles Loaded with Metformin for Effective Against Hepatocellular Cancer Stem Cells.

Introduction: Hepatocellular cancer stem cells (CSCs) play crucial roles in hepatocellular cancer initiation, development, relapse, and metastasis. Therefore, eradication of this cell population is a primary objective in hepatocellular cancer therapy. We prepared a nanodrug delivery system with activated carbon nanoparticles (ACNP) as carriers and metformin (MET) as drug (ACNP-MET), which was able to selectively eliminate hepatocellular CSCs and thereby increase the effects of MET on hepatocellular cancers. Methods: ACNP were prepared by ball milling and deposition in distilled water. Suspension of ACNP and MET was mixed and the best ratio of ACNP and MET was determined based on the isothermal adsorption formula. Hepatocellular CSCs were identified as CD133+ cells and cultured in serum-free medium. We investigated the effects of ACNP-MET on hepatocellular CSCs, including the inhibitory effects, the targeting efficiency, self-renewal capacity, and the sphere-forming capacity of hepatocellular CSCs. Next, we evaluated the therapeutic efficacy of ACNP-MET by using in vivo relapsed tumor models of hepatocellular CSCs. Results: The ACNP have a similar size, a regular spherical shape and a smooth surface. The optimal ratio for adsorption was MET: ACNP=1:4. ACNP-MET could target and inhibit the proliferation of CD133+ population and decrease mammosphere formation and renewal of CD133+ population in vitro and in vivo. Conclusion: These results not only suggest that nanodrug delivery system increased the effects of MET, but also shed light on the mechanisms of the therapeutic effects of MET and ACNP-MET on hepatocellular cancers. ACNP, as a good nano-carrier, could strengthen the effect of MET by carrying drugs to the micro-environment of hepatocellular CSCs.

Adsorbent-to-photocatalyst: Recycling heavy metal cadmium by natural clay mineral for visible-light-driven photocatalytic antibacterial.

High value-added recycling of hazardous substances emerges as one of the most promising directions in current society, which can simultaneously relieve the environmental burden and obtain useful products. Here, we propose a transformation strategy from adsorbent to photocatalyst by recycling heavy metal with natural clay mineral. Sepiolite is selected as an adsorbent for removing Cd2+ in wastewater due to its excellent adsorption properties in terms of high specific surface area and structural channels. Then, in-situ sulfidation of the adsorbed Cd2+ is carried out, transforming it into CdS/Sep photocatalyst, which exhibits efficient photocatalytic antibacterial activity for Escherichia coli with a sterilization efficiency of 98.8% within 2 h. The intense visible light absorption of CdS and the efficient separation of photogenerated carriers render the prominent antibacterial activity. The main reactive species including superoxide radicals and hydroxyl radicals produced by CdS/Sep under visible light irradiation are diffused into the solution and attack the bacteria surrounding the photocatalysts. This work not only develops new ideas for recycling heavy metals for fabrication of efficient photocatalysts, but also provides a reference for water purification based on cost-effective natural minerals.

Effect of RNA Interference Inhibiting the Expression of the FUBP1 Gene on Biological Function of Gastric Cancer Cell Line SGC7901.

BACKGROUND: The research aimed to observe the effect of gene silencing on the proliferation, migration, cell cycle, apoptosis, and other biological functions of human gastric cancer cells with RNA interference inhibiting the expression of the far upstream element-binding protein 1 (FUBP1) in the gastric cancer cell line SGC7901. METHODS: The shRNA lentivirus vector of the target gene FUBP1 was constructed to transfect the gastric cancer cell line SGC7901. The qRT-PCR and western blot assays were used to detect the expression levels of FUBP1 mRNA and protein in the gastric cancer cells. The CCK-8 assay was used to detect the proliferation of gastric cancer cells. The cell scratch assay and the transwell assays were used to detect the migration of gastric cancer cells. Flow cytometry was used to detect cell cycle distribution and apoptosis. RESULTS: The shRNA lentiviral vector of FUBP1 was successfully transfected into the gastric cancer cell line SGC7901, and could effectively reduce the expression of mRNA and protein of FUBP1. The silencing of FUBP1 could inhibit the gastric cancer cell proliferation and affect the distribution of the cell cycle, resulting in S-phase arrest and cell growth inhibition. However, FUBP1 silencing has no significant effect on cell apoptosis and migration. CONCLUSIONS: The expression of FUBP1 can be inhibited specifically and effectively by RNA interference technology, which can significantly affect the biological function of the gastric cancer cell line SGC7901.

Ultra-small gold nanoparticles self-assembled by gadolinium ions for enhanced photothermal/photodynamic liver cancer therapy.

Gold nanomaterials are widely used in biomedical research as drug delivery systems, imaging agents and therapeutic materials owing to their unique physicochemical properties and high biocompatibility. In this study, we prepared ultra-small gold nanoparticles (AuNPs) and induced them with gadolinium ions to form a spherical self-assembly. The nanoparticles were coupled with matrix metalloproteinase-2 (MMP-2) and loaded with the photosensitive drug IR820 for photothermal/photodynamic combination therapy of liver cancer. The formed nanoprobes were metabolised in vivo via degradation under dual-mode real-time imaging because of their acid response degradation characteristics. In addition, the nanoprobe showed excellent tumour-targeting ability due to the presence of surface-modified MMP-2. In vivo treatment experiments revealed that the nanoprobes achieved enhanced photodynamic/photothermal combination therapy under laser irradiation and significantly inhibited tumour growth. Therefore, the nanoprobes have great potential for anti-tumour therapy guided by dual-mode real-time imaging of liver cancer.

A Novel Therapeutic siRNA Nanoparticle Designed for Dual-Targeting CD44 and Gli1 of Gastric Cancer Stem Cells.

PURPOSE: Gastric cancer stem cells (CSCs) are important for the initiation, growth, recurrence, and metastasis of gastric cancer, due to their chemo-resistance and indefinite proliferation. Herein, to eliminate gastric CSCs, we developed novel CSC-targeting glioma-associated oncogene homolog 1 (Gli1) small interfering RNA (siRNA) nanoparticles that are specifically guided by a di-stearoyl-phosphatidyl-ethanolamine- hyaluronic-acid (DSPE-HA) single-point conjugate, as an intrinsic ligand of the CD44 receptor. We refer to these as targeting Gli1 siRNA nanoparticles. METHODS: We used the reductive amination reaction method for attaching amine groups of DSPE to aldehydic group of hyaluronic acid (HA) at the reducing end, to synthesize the DSPE-HA single-point conjugate. Next, targeting Gli1 siRNA nanoparticles were prepared using the layer-by-layer assembly method. We characterized the stem cellular features of targeting Gli1 siRNA nanoparticles, including their targeting efficiency, self-renewal capacity, the migration and invasion capacity of gastric CSCs, and the penetration ability of 3D tumor spheroids. Next, we evaluated the therapeutic efficacy of the targeting Gli1 siRNA nanoparticles by using in vivo relapsed tumor models of gastric CSCs. RESULTS: Compared with the multipoint conjugates, DSPE-HA single-point conjugates on the surface of nanoparticles showed significantly higher binding affinities with CD44. The targeting Gli1 siRNA nanoparticles significantly decreased Gli1 protein expression, inhibited CSC tumor spheroid and colony formation, and suppressed cell migration and invasion. Furthermore, in vivo imaging demonstrated that targeting Gli1 siRNA nanoparticles accumulated in tumor tissues, showing significant antitumor recurrence efficacy in vivo. CONCLUSION: In summary, our targeting Gli1 siRNA nanoparticles significantly inhibited CSC malignancy features by specifically blocking Hedgehog (Hh) signaling both in vitro and in vivo, suggesting that this novel siRNA delivery system that specifically eliminates gastric CSCs provides a promising targeted therapeutic strategy for gastric cancer treatment.

To reduce premature drug release while ensuring burst intracellular drug release of solid lipid nanoparticle-based drug delivery system with clathrin modification.

Nanoscale drug delivery system (NDDS) with slow premature drug release (PDR) while ensuring burst intracellular drug release (BIDR) is becoming a hot point in NDDS-based nanomedicine. Here we used clathrin to modify a solid lipid nanoparticle (SLN)-based NDDS of salinomycin (SLN-SAL) to prepare NDDS with reduced PDR while ensuring BIDR. Drug-release-kinetic experiments revealed that clathrin modified SLN-SAL (CMSLN-SAL) reduced PDR while ensured BIDR of its prototype NDDS, SLN-SAL. Mechanism experiments revealed that clathrin modification reduced PDR of SLN-SAL through increasing the mechanical strength of SLN-SAL and ensured BIDR of SLN-SAL through lipid membrane fusion after its clathrin shell was de-polymerized by a cytoplasm enzyme, HSC70. In addition, CMSLN-SAL had significantly higher intracellular uptake and stronger inhibitive effects on cancer cells than that of SLN-SAL. These results demonstrated that clathrin modification is an effective way to reduce PDR while ensuring BIDR and increasing the anticancer effects of SLN-based NDDS.

Generation of Alzheimer's Disease Transgenic Zebrafish Expressing Human APP Mutation Under Control of Zebrafish appb Promotor.

BACKGROUND: Amyloid peptide precursor (APP) as the precursor protein of peptide betaamyloid (ß-amyloid, Aß), which is thought to play a central role in the pathogenesis of Alzheimer's disease (AD), also has an important effect on the development and progression of AD. Through knocking-in APP gene in animals, numerous transgenic AD models have been set up for the investigation of the mechanisms behind AD pathogenesis and the screening of anti-AD drugs. However, there are some limitations to these models and here is a need for such an AD model that is economic as well as has satisfactory genetic homology with human. METHODS: We generated a new AD transgenic model by knocking a mutant human APP gene (APPsw) in zebrafish with appb promoter of zebrafish to drive the expression of APPsw. RESULTS: Fluorescent image and immunochemistry stain showed and RT-PCR and western blot assay confirmed that APPsw was successfully expressed in the brain, heart, eyes and vasculature of the transgenic zebrafish. Behavioral observation demonstrated that the transgenic zebrafish had AD-like symptoms. Histopathological observation found that there were cerebral ß-amyloidosis and angiopathy (CAA), which induced neuron loss and enlarged pervascular space. CONCLUSION: These results suggest that APPsw transgenic zebrafish well simulate the pathological characters of AD and can be used as an economic AD transgenic model. Furthermore, the new model suggested that APP can express in microvasculatures and cause the Aß generation and deposition in cerebral vessel which further destroys cerebral vascular structure resulting in the development and/or the progress of AD.

CD20 monoclonal antibody targeted nanoscale drug delivery system for doxorubicin chemotherapy: an in vitro study of cell lysis of CD20-positive Raji cells.

A monoclonal antibody targeted nanoscale drug delivery system (NDDS) for chemotherapy was evaluated in CD20-positive Raji cells in vitro. Nanoparticles were formed by the assembly of an amphiphilic polymer consisting of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxypolyethyleneglycol-2000 (DSPE-PEG2000). Active carbon nanoparticles (ACNP) were conjugated to the chemotherapeutic agent, doxorubicin (DOX), and the nanoliposome carrier, DSPE-PEG2000 and DSPE-PEG2000-NH2 conjugated to the human anti-CD20 monoclonal antibody that targets B-lymphocytes. This monoclonal antibody targeted nanoparticle delivery system for chemotherapy formed the active NDDS complex, ACNP-DOX-DSPE-PEG2000-anti-CD20. This active NDDS was spherical in morphology and had good dispersion in the culture medium. When compared with the effects on CD20-negative YTS cells derived from natural killer/T-cell lymphoma, the active NDDS, ACNP-DOX-DSPE-PEG2000-anti-CD20, demonstrated DOX delivery to CD20-positive Raji cells derived from Burkitt's lymphoma (B cell lymphoma), resulting in increased cell killing in vitro. The intracellular targeting efficiency of the ACNP-DOX-DSPE-PEG2000-anti-CD20 complex was assessed by confocal laser microscopy and flow cytometry. The findings of this in vitro study have shown that the DSPE-PEG2000 polymeric liposome is an effective nanocarrier of both a monoclonal antibody and a chemotherapy agent and can be used to target chemotherapy to specific cells, in this case to CD20-positive B-cells. Future developments in this form of targeted therapy will depend on the development of monoclonal antibodies that are specific for malignant cells, including antibodies that can distinguish between lymphoma cells and normal lymphocyte subsets.

Folic Acid Functionalized γ-Cyclodextrin C60, A Novel Vehicle for Tumor-Targeted Drug Delivery.

Folic acid (FA)-γ cyclodextrin (γ CD)-C60 was synthesized in this study as a carrier for tumor-targeted drug delivery to enhance the anticancer effect of carboplatin (CBP). FA-γ CD and C60-CBP were prepared and C60-CBP was then entrapped into FA-γ CD through host-guest effect. FA-γ CD-C60 significantly increased the intracellular uptake and release of CBP, thereby providing higher cytotoxicity against the HeLa cells with high expression of folate receptor (FR). In vivo experiments revealed that FA-γ CD-C60-CBP had more significant anticancer effects than CBP alone, showing no obvious toxic effects on zebrafish at concentration as high as 500 µg/mL. These results suggest that FA-γ CD-C60 may provide an effective strategy for administration of antineoplastics, with great promise in future targeted therapy for cancers.

The effect of hyaluronic acid functionalized carbon nanotubes loaded with salinomycin on gastric cancer stem cells.

Gastric cancer stem cells (CSCs) play a crucial role in the initiation, development, relapse and metastasis of gastric cancer because they are resistant to a standard chemotherapy and the residual CSCs are able to proliferate indefinitely. Therefore, eradication of this cell population is a primary objective in gastric cancer therapy. Here, we report a gastric CSCs-specifically targeting drug delivery system (SAL-SWNT-CHI-HA complexes) based on chitosan(CHI) coated single wall carbon nanotubes (SWNTs) loaded with salinomycin (SAL) functionalized with hyaluronic acid (HA) can selectively eliminate gastric CSCs. Gastric CSCs were identified as CD44+ cells and cultured in serum-free medium. SAL-SWNT-CHI-HA complexes were capable of inhibiting the self-renewal capacity of CD44+ population, and decrease mammosphere- and colon-formation of CSCs. In addition, the migration and invasion of gastric CSCs were significantly blocked by SAL-SWNT-CHI-HA complexes. Quantitative and qualitative analysis of cellular uptake demonstrated that HA functionalization facilitated the uptake of SWNTs in gastric CSCs while free HA competitively inhibited cellular uptake of SAL-SWNT-CHI-HA delivery system, revealing the mechanism of CD44 receptor-mediated endocytosis. The SAL-SWNT-CHI-HA complexes showed the strongest antitumor efficacy in gastric CSCs by inducing apoptosis, and in CSCs mammospheres by penetrating deeply into the core. Taken altogether, our studies demonstrated that this gastric CSCs-targeted SAL-SWNT-CHI-HA complexes would provide a potential strategy to selectively target and efficiently eradicate gastric CSCs, which is promising to overcome the recurrence and metastasis of gastric cancer and improve gastric cancer treatment.

The application of carbon nanotubes in target drug delivery systems for cancer therapies.

Among all cancer treatment options, chemotherapy continues to play a major role in killing free cancer cells and removing undetectable tumor micro-focuses. Although chemotherapies are successful in some cases, systemic toxicity may develop at the same time due to lack of selectivity of the drugs for cancer tissues and cells, which often leads to the failure of chemotherapies. Obviously, the therapeutic effects will be revolutionarily improved if human can deliver the anticancer drugs with high selectivity to cancer cells or cancer tissues. This selective delivery of the drugs has been called target treatment. To realize target treatment, the first step of the strategies is to build up effective target drug delivery systems. Generally speaking, such a system is often made up of the carriers and drugs, of which the carriers play the roles of target delivery. An ideal carrier for target drug delivery systems should have three pre-requisites for their functions: (1) they themselves have target effects; (2) they have sufficiently strong adsorptive effects for anticancer drugs to ensure they can transport the drugs to the effect-relevant sites; and (3) they can release the drugs from them in the effect-relevant sites, and only in this way can the treatment effects develop. The transporting capabilities of carbon nanotubes combined with appropriate surface modifications and their unique physicochemical properties show great promise to meet the three pre-requisites. Here, we review the progress in the study on the application of carbon nanotubes as target carriers in drug delivery systems for cancer therapies.

Silica nanorattle-doxorubicin-anchored mesenchymal stem cells for tumor-tropic therapy.

Low targeting efficiency is one of the biggest limitations for nanoparticulate drug delivery system-based cancer therapy. In this study, an efficient approach for tumor-targeted drug delivery was developed with mesenchymal stem cells as the targeting vehicle and a silica nanorattle as the drug carrier. A silica nanorattle-doxorubicin drug delivery system was efficiently anchored to mesenchymal stem cells (MSCs) by specific antibody-antigen recognitions at the cytomembrane interface without any cell preconditioning. Up to 1500 nanoparticles were uploaded to each MSC cell with high cell viability and tumor-tropic ability. The intracellular retention time of the silica nanorattle was no less than 48 h, which is sufficient for cell-directed tumor-tropic delivery. In vivo experiments proved that the burdened MSCs can track down the U251 glioma tumor cells more efficiently and deliver doxorubicin with wider distribution and longer retention lifetime in tumor tissues compared with free DOX and silica nanorattle-encapsulated DOX. The increased and prolonged DOX intratumoral distribution further contributed to significantly enhanced tumor-cell apoptosis. This strategy has potential to be developed as a robust and generalizable method for targeted tumor therapy with high efficiency and low systematic toxicity.

An investigation of the effects of nanosize delivery system for antisense oligonucleotide on esophageal squamous cancer cells.

Telomerase is an RNA-dependent DNA polymerase that synthesizes telomeric DNA sequences, which provide tandem GT-rich repeats (TTAGGG)n to compensate telomere shortening and play an important role in cellular aging and carcinogenesis.(1) Recent studies demonstrated that telomerase activity is absent in most normal human somatic cells but present in over 90% of tumor cells and immortalized cells. Human telomerase reverse transcriptase (hTERT) is the rate-limiting factor of telomerase activity and also ASODN (antisense oligodeoxynucleotides) targeting to hTERT gene represent a promising approach to tumor therapy. However, the use of ASODN is determined by combination of biological stability, successful uptake into the targeted cells, resistance to nucleases and so forth. To satisfy these conditions, the key is to establish proper delivery system to carry and protect ASODN. Accumulating data have revealed that polyethylenimine (PEI) with numerous positive charges is one of the most effective DNA-delivery systems in vitro and in vivo due to its polycationic property and proton sponge mechanism, however, it lacks the function of targeting to tumor cells. Recently, some studies indicated that coupling special ligand like NGR (N: asparagine, G: glycine, R: arginine) peptide targeting to tumor blood vessels with delivery system can enhance the efficacy of gene transfection. The purpose of this study was to investigate the effects of nanosize delivery system for antisense oligonucleotide for hTERT in vitro on EC9706 cells and in vivo on tumor tissue.

[The correlated research of acute graft versus host disease after allogeneic stem cell transplantation].

OBJECTIVE: To analyze the relationship between the expression of FasL, Perforin and Granzyme B and the development of acute graft versus host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: The peripheral blood mRNA expression of granzyme B, perforin, fasL from 17 patients after allo-HSCT was detected by competitive quantitative RT-PCR and the relationship between FasL, Granzyme B and Perforin expressions and clinical symptom of aGVHD was analyzed. RESULTS: The expression level of Granzyme B, Perforin and FasL was 4.6 +/- 0.2, 4.5 +/- 0.1, 1.4 +/- 0.1 before aGVHD occurrence respectively, and was 98.7 +/- 2.5, 91.8 +/- 3.4, 61.5 +/- 2.2, after the occurrence in 14 patients (P < or = 0.05). Over expressions of Granzyme B, Perforin, and FasL during acute GVHD were detected in 13 of 14, 12 of 14, and 12 of 14 patients respectively. The upregulated expressions occurred prior to clinical symptom of aGVHD. CONCLUSION: The expressions of Granzyme B, Perforin, and FasL were significantly high in patients with acute aGVHD. Monitoring of the expressions, might predict the occurrence of clinical aGVHD and it severity and prognosis.

[Intraperitoneal chemotherapy with mitomycin C bound to activated carbon nanoparticles for nude mice bearing human gastric carcinoma].

OBJECTIVE: To prepare a new dosage formulation of activated carbon nanoparticles adsorbing mitomycin C (MMC-ACNP) and evaluate the beneficial effects of intraperitoneally applied MMC-ACNP as a drug delivery system for lymphatic targeting in preventing metastasis and recurrence of gastric cancer. METHODS: MMC-ACNP was prepared. Acute toxicity after its intraperitoneal administration was evaluated. An experiment on nude mice model with transplanted human gastric cancer in 6 groups was completed to assess the effects of drugs on intra-abdominal carcinomatosis. RESULTS: The LD50 of MMC-ACNP was 46.80 mg/kg (in terms of MMC) while that of MMC aqueous solution was 9.33 mg/kg. The toxicity of MMC-ACNP was much less than that of the solution form. MMC-ACNP was superior to MMC aqueous solution in controlling carcinomatosis and tumor growth by intraperitoneal administration. Despite the high dose of MMC, leukopenia and thrombocytopenia were not observed in the MMC-ACNP treated group. Fine activated carbon particles adsorbing MMC entered the nuclei of tumor cells, so that the effects of the anticancer drug were reinforced. CONCLUSION: MMC-ACNP gives a good promise of clinical use due to its advantages such as high selectivity and low toxicity.