Wangwen Gu

The performance of docetaxel-loaded solid lipid nanoparticles targeted to hepatocellular carcinoma

Human hepatocellular carcinoma (HCC) is one of the major causes of death worldwide. Targeted uptake of therapeutic agent in the cell-, tissue- or disease-specific manner represents a potential technology for the treatment of HCC. A new docetaxel-loaded hepatoma-targeted solid lipid nanoparticle (tSLN) was designed and prepared with galactosylated dioleoylphosphatidyl ethanolamine. The cellular cytotoxicity, cellular uptake, subcellular localization, in vivo toxicity, therapeutic effect, biodistribution and histology of tSLNs were investigated. The tSLNs showed the particle size about 120nm with encapsulation efficiency >90%, a low burst effect within the first day and a sustained release for the next 29 days in vitro. Cytotoxicity of tSLNs against hepatocellular carcinoma cell line BEL7402 was superior to Taxotere and non-targeted SLNs (nSLNs). The tSLNs also showed better tolerant and antitumor efficacy in murine model bearing hepatoma compared with Taxotere or nSLNs. The studies on cellular uptake and biodistribution indicated that the better antitumor efficacy of tSLNs was attributed to both the increased accumulation of drug in tumor and more cellular uptake by hepatoma cells. The histology demonstrated that tSLNs had no detrimental effect on both healthy liver and liver with fibrosis. These results implied that this targeted nanocarrier of docetaxel could enhance its antitumor effect in vivo with low systemic toxicity for the treatment of locally advanced and metastatic HCC.

Arginine-chitosan/DNA self-assemble nanoparticles for gene delivery: In vitro characteristics and transfection efficiency

Chitosan (Cs) is a natural cationic polysaccharide that has shown potential as non-viral vector for gene delivery because of its biocompatibility and low toxicity. However, chitosan used for gene delivery is limited due to its poor water solubility and low transfection efficiency. The purpose of this work was to prepare Arginine-chitosan (Arg-Cs)/DNA self-assemble nanoparticles (ACSNs), and determine their in vitro characteristics and transfection efficiency against HEK 293 and COS-7 cells. Our experimental results showed that the particle size and zeta potential of ACSNs prepared with different N/P ratios were 200-400nm and 0.23-12.25mV, respectively. The in vitro transfection efficiency of ACSNs showed dependence on pH of transfection medium, and the highest expression efficiency was obtained at pH 7.2. The transfection efficiency increased with the ratio of chitosan-amine/DNA phosphate (N/P ratio) from 1 to 5, and reached the highest level with the N/P ratio 5. Effect of plasmid dosage on the transfection efficiency showed the highest transfection efficiency was obtained at 4microg/well for HEK 293 cells and 6microg/well for COS-7 cells. The transfection efficiency of ACSNs was much higher than that of Cs/DNA self-assemble nanoparticles (CSNs). The average cell viability of ACSNs was over 90%. These results suggested that ACSNs could be a safe and effective non-viral vector for gene delivery.

Overcoming multidrug resistance by co-delivery of Mdr-1 and survivin-targeting RNA with reduction-responsible cationic poly(β-amino esters).

Multidrug resistance (MDR) remains one of the main challenges in the successful chemotherapy of human cancer. RNA interference (RNAi) strategy aiming at only one cause of MDR was widely applied, nevertheless hardly obtained satisfactory tumor-suppressing effect. In this work, a new attempt to package two kinds of RNA with different functions into one vector and reverse MDR against two different mechanisms via RNAi was carried out. A new bioreducible poly (β-amino esters) (PAEs), poly[bis(2-hydroxylethyl)-disulfide-diacrylate-β-tetraethylenepentamine] (PAP) was synthesized by Michael addition reaction. The PAEs/RNA complex nanoparticles (PAEN) were prepared. The experimental results demonstrated that co-delivery of iMdr-1-shRNA and iSurvivin-shRNA could be achieved by a single vector, and interfering two genes simultaneously had a synergistic effect on overcoming MDR. PAEN lowered the IC(50) value of doxorubicin (DOX) in MDR tumor cells to a comparable level to that in the sensitive cell line through down-regulating the expression of P-gp and Survivin, and decreased the tumor volumes in mice xenograft model bearing DOX-resistant human breast cancer when combined with DOX. These results illustrated that PAEN could be applied as potential efficient non-viral RNA carriers for reversing MDR.

Cancer-Cell-Biomimetic Nanoparticles for Targeted Therapy of Homotypic Tumors

A unique biomimetic drug-delivery system composed of 4T1-breast-cancer-cell membranes and paclitaxel-loaded polymeric nanoparticles (PPNs) (cell-membrane-coated PPNs), demonstrates superior interactions to its source tumor cells and elongated blood circulation, and displays highly cell-specific targeting of the homotypic primary tumor and metastases, with successful inhibition of the growth and lung metastasis of the breast cancer cells.

Inhibition of metastasis and growth of breast cancer by pH-sensitive poly (β-amino ester) nanoparticles co-delivering two siRNA and paclitaxel.

Breast cancer is the most vicious killer for womens health, while metastasis is the main culprit, which leads to failure of treatment by increasing relapse rate. In this work, a new complexes nanoparticles loading two siRNA (Snail siRNA (siSna) and Twist siRNA (siTwi)) and paclitaxel (PTX) were designed and constructed using two new amphiphilic polymer, polyethyleneimine-block-poly[(1,4-butanediol)-diacrylate-β-5-hydroxyamylamine] (PEI-PDHA) and polyethylene glycol-block-poly[(1,4-butanediol)-diacrylate-β-5-hydroxyamylamine] (PEG-PDHA) by self-assembly. The experimental results showed that in the 4T1 tumor-bearing mice models, PEI-PDHA/PEG-PDHA/PTX/siSna/siTwi) complex nanoparticles (PPSTs) raised the accumulation and retention of both PTX and siRNA in tumor after administrated intravenously, resulted in the strong inhibition of the tumor growth and metastasis simultaneously. It was found that co-delivery of siSna and siTwi had more significant anti-metastasis effect than delivering a single siRNA, as a result of simultaneously inhibiting the motility of cancer cells and degradation of ECM. Therefore, PPSTs could be a promising co-delivery vector for effective therapy of metastatic breast cancer.

Targeted Nanoassembly Loaded with Docetaxel Improves Intracellular Drug Delivery and Efficacy in Murine Breast Cancer Model

Docetaxel is one of the most promising chemotherapeutic agents for the treatment of metastatic breast cancer, but it shows fearful side effects. We hypothesized that a novel targeted nanoassembly (TNA) could provide efficient intracellular drug delivery in breast tumor cells overexpressing epidermal growth factor (EGF) receptor and thus improve the efficacy and reduce the side effects of docetaxel. We prepared the novel docetaxel loaded TNAs formed by polyethylene glycol-distearoylphosphatidylethanolamine (PEG-DSPE) and modified with EGF. Compared with nontargeted nanoassemblies (NNAs), TNAs showed obvious improvement of cell-specific uptake and internalization, and revealed more cytotoxicity against MDA-MB-468 cells by inducing more late apoptosis and subG1 cells at low drug concentration, or more G2/M arrest at high drug concentration than NNAs or Taxotere. In BALB/c mice bearing breast tumor xenografts, TNAs showed stronger inhibition of tumor growth compared with NNAs (relative tumor volume in mice treated with 5 mg/kg TNAs = 0.99 and 10 mg/kg NNAs = 1.71, p < 0.05) or Taxotere (relative tumor volume in mice treated with 5 mg/kg TNAs = 0.99 and 10 mg/kg Taxotere = 4.20, p < 0.01). In particular, tumor disappeared completely in the TNA group at a dose of 10 mg/kg. The maximum tolerated dose (MTD) of TNAs was about four times higher than that of Taxotere. TNAs also demonstrated a much longer circulation time in vivo and more drug accumulation in tumor in a murine breast cancer model than Taxotere. TNA treatment also prolonged survival of mice. These results suggested that TNAs could have more potential as a delivery system for breast cancer chemotherapy.

Induction of apoptosis in non-small cell lung cancer by downregulation of MDM2 using pH-responsive PMPC-b-PDPA/siRNA complex nanoparticles.

Non-small cell lung cancer (NSCLC) accounts for the majority of lung cancer caused human death. In this work, we selected oncogene mouse double minute 2 (MDM2) as a therapeutic target for NSCLC treatment and proposed that sufficient MDM2 knockdown could inhibit tumor growth via induction of cell cycle arrest and cancer cell apoptosis. On this regard, a new pH-responsive diblock copolymer of poly(methacryloyloxy ethyl phosphorylcholine)-block-poly(diisopropanolamine ethyl methacrylate) (PMPC-b-PDPA)/siRNA-MDM2 complex nanoparticle with minimized surface charge and suitable particle size was designed and developed for siRNA-MDM2 delivery in vitro and in vivo. The experimental results showed that the nanoparticles were spherical with particle size around 50 nm. MDM2 knockdown in p53 mutant NSCLC H2009 cells induced significant cell cycle arrest, apoptosis and growth inhibition through upregulation of p21 and activation of caspase-3. Furthermore, the growth of H2009 xenograft tumor in nude mice was inhibited via repeated injection of PMPC-b-PDPA/siRNA-MDM2 complex nanoparticles. These results suggested that PMPC-b-PDPA/siRNA complex nanoparticles targeting a unique set of oncogenes could be developed into a new therapeutic approach for NSCLC treatment.

The role of daidzein-loaded sterically stabilized solid lipid nanoparticles in therapy for cardio-cerebrovascular diseases

Daidzein is a very good candidate for treating cardio-cerebrovascular diseases, but its poor oral absorption and bioavailability limit its curative efficacy. In this work, daidzein-loaded solid lipid nanoparticles (SLNs) with PEGylated phospholipid as stabilizer were successfully prepared by hot homogenization method. SLNs showed the mean particle size 126+/-14 nm with entrapment efficiency 82.5+/-3.7%. In vitro release of SLNs demonstrated a sustained release manner with cumulative release over 90% within 120 h in bovine serum albumin solution (4%, w/v). The pharmacokinetic behavior showed that SLNs loading daidzein could significantly increase circulation time compared with orally administrated daidzein suspension or intravenously delivered daidzein solution. SLNs showed the better effect on cardiovascular system of the anesthetic dogs by reducing the myocardial oxygen consumption (MOC) and the coronary resistance (CR) in heart compared with oral suspension or intravenous solution. The SLNs demonstrated the best effect on cerebrovascular system by increasing cerebral blood flow (CeBF) and reducing cerebrovascular resistance (CeR) in anesthetized dogs, and the protective effect on rats with ischemia-reperfusion injury model among three formulations. These results suggested that SLNs could be a potential candidate for the treatment of cardio-cerebrovascular diseases.

A Smart Nanoassembly Consisting of Acid-Labile Vinyl Ether PEG−DOPE and Protamine for Gene Delivery: Preparation and in Vitro Transfection

The conception of a modular designed and viruslike nonviral vector has been presented for gene delivery. Recently, we constructed a new smart nanoassembly (SNA) with multifunctional components that was composed of a condensed core of pDNA with protamine sulfate (PS) and a dioleoyl phosphatidylethanolamine (DOPE)-based lipid envelope containing poly(ethylene glycol)--vinyl ether--DOPE (PVD). SNAs with mPEG 2000 (SNAs1) or mPEG 5000 (SNAs2) loading PS/DNA were prepared by the lipid film hydration technique. The particle size was about 160 nm for SNAs1 and 240 nm for SNAs2 loading PS/DNA (10:1 w/w), and the zeta potential was about 4 mV for two SNAs. The in vitro release experiment indicated that PVD possessed a good ability for self-dePEGylation, which could result in the recovery of an excellent fusogenic capacity of DOPE at low pH. SNAs showed a higher transfection efficiency and much lower cytotoxicity than did Lipofectamine 2000 on HEK 293, HeLa, and COS-7 cells. The cellular uptake and subcellular localization demonstrated that the superior transfection efficiency of SNAs could result from the fact that the DOPE-based lipid envelope containing PVD increased PS/DNA in the cytoplasm, and protamine enhanced the nuclear delivery or overcame the nuclear membrane barrier. These results implied that the PVD-based nanoassembly loading PS/DNA could be a promising gene delivery system.

Codelivery of Sorafenib and Curcumin by Directed Self-Assembled Nanoparticles Enhances Therapeutic Effect on Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related mortality worldwide. Herein, we first reported the codelivery of sorafenib and curcumin by directed self-assembled nanoparticles (SCN) to enhance the therapeutic effect on HCC. SCN was formed by employing the hydrophobic interactions among the lipophilic structure in sorafenib, curcumin, and similar hydrophobic segments of polyethylene glycol derivative of vitamin E succinate (PEG-VES), which comprised uniform spherical particles with particle size of 84.97 ± 6.03 nm. SCN presented superior effects over sorafenib, curcumin, and their physical mixture (Sora + Cur) on enhancing in vitro cytotoxicity and cell apoptosis in BEL-7402 cells and Hep G2 cells, and antiangiogenesis activities in tube formation and microvessel formation from aortic rings. Moreover, the tissue concentration of sorafenib and curcumin in gastrointestinal tract and major organs were significantly improved after their coassembly into SCN. In particular, in BEL-7402 cells induced tumor xenograft, SCN treatment displayed the obviously enhanced inhibitory effect on tumor progression over free drug monotherapy or their physical mixture, with significantly increased antiproliferation and antiangiogenesis capability. Thereby, the codelivered nanoassemblies of sorafenib and curcumin provided a promising strategy to enhance the combinational therapy of HCC.