Xueyan Zhang

The enhanced effect of surface microstructured porous titanium on adhesion and osteoblastic differentiation of mesenchymal stem cells.

Porous titanium with appropriate surface treatments can be osteoinductive. To investigate the effect of surface treatments of porous titanium on the attachment and differentiation of mesenchymal stem cells (MSCs), two kinds of surface microstructured porous titaniums, H2O2/TaCl5 treated one (HTPT), and H2O2/TaCl5 and subsequent simulated body fluid (SBF) treated one (STPT) were fabricated, and non-treated one (NTPT) was used as control. The morphology, specific surface area (SSA), pore distribution and mechanical strength of these materials were characterized respectively, and the results showed that H2O2/TaCl5 treatment led to a significant increase in both SSA and micropores of HTPT, and the further SBF immersion resulted in the formation of a layer of bone-like apatite on the surface of STPT. Although the surface treatments had a little negative impact on the compressive strength and elasticity modulus of porous titanium, the mechanical strength of HTPT or STPT was enough for the bone defect repair of the load-bearing sites. The protein adsorption and cell adhesion experiments confirmed that the microstructured surface notably enhanced porous titanium’s protein binding capacity and promoted MSCs adhesion on the surface. More importantly, cell differentiation experiments proved that the microstructured surface evidently elevated the osteoblastic gene expressions of MSCs compared to NTPT. The enhanced biological effect by the surface treatments was more robust on STPT. Therefore, our results suggest that the microstructured surface has great potential for promoting MSCs differentiation towards osteoblasts, giving excellent support for the osteoinduction of porous titanium with appropriate surface treatments.

Codelivery of SH-aspirin and curcumin by mPEG-PLGA nanoparticles enhanced antitumor activity by inducing mitochondrial apoptosis.

Natural product curcumin (Cur) and H2S-releasing prodrug SH-aspirin (SH-ASA) are potential anticancer agents with diverse mechanisms, but their clinical application prospects are restricted by hydrophobicity and limited efficiency. In this work, we coencapsulated SH-ASA and Cur into methoxy poly(ethylene glycol)-poly (lactide-coglycolide) (mPEG-PLGA) nanoparticles through a modified oil-in-water single-emulsion solvent evaporation process. The prepared SH-ASA/Cur-coloaded mPEG-PLGA nanoparticles had a mean particle size of 122.3±6.8 nm and were monodispersed (polydispersity index =0.179±0.016) in water, with high drug-loading capacity and stability. Intriguingly, by treating with SH-ASA/Cur-coloaded mPEG-PLGA nanoparticles, obvious synergistic anticancer effects on ES-2 and SKOV3 human ovarian carcinoma cells were observed in vitro, and activation of the mitochondrial apoptosis pathway was indicated. Our results demonstrated that SH-ASA/Cur-coloaded mPEG-PLGA nanoparticles could have potential clinical advantages for the treatment of ovarian cancer.

The novel complex combination of alum, CpG ODN and HH2 as adjuvant in cancer vaccine effectively suppresses tumor growth in vivo

Single-component adjuvant is prone to eliciting a specific type of Th1 or Th2 response. So, the development of combinatorial adjuvants inducing a robust mixed Th1/Th2 response is a promising vaccination strategy against cancer. Here, we describe a novel combination of aluminum salts (alum), CpG oligodeoxynucleotide (CpG) and innate defense regulator peptide HH2 for improving anti-tumor immune responses. The CpG-HH2 complex significantly enhanced the production of IFN-γ, TNF-α and IL-1β, promoted the uptake of antigen and strengthened the activation of p38, Erk1/2 and NF-κB in vitro, compared to CpG or HH2 alone. Immunization with NY-ESO-1 antigen plus alum-CpG-HH2 combinatorial adjuvant effectively inhibited tumor growth and reduced tumor burden in prophylactic and therapeutic tumor models and even in passive serum or cellular therapy. In addition, co-administration of NY-ESO-1 with alum-CpG-HH2 combinatorial adjuvant markedly activated NK cell cytotoxicity, induced antibody-dependent cellular cytotoxicity (ADCC), dramatically elicited cytotoxic T lymphocytes (CTLs) response, and increased infiltrating lymphocytes in tumors. Moreover, in vivo depletion of CD8+ T cells completely and depletion of NK cells partially blocked the anti-tumor activity of NY-ESO-1-alum-CpG-HH2 immunization. Overall, our results demonstrate a novel adjuvant combination for cancer vaccine with efficient immunomodulation by stimulating innate immunity and mediating adaptive immunity.

Delivery of a Modified mRNA Encoding IL-22 Binding Protein (IL-22BP) for Colon Cancer Gene Therapy

As an alternative form of genetic material, mRNA lacks a CpG island and can function without crossing the nuclear membrane. These properties make mRNA less of a potential immune stimulant than plasmid DNA. Therefore, chemically modified mRNA is an effective alternative to plasmid DNA for gene therapy. In this study, cationic liposomes were used as a vector to transport mRNA complexes that had been compressed using protamine and to obtain high mRNA transport and expression efficiency. The liposome-protamine-IL-22BP mRNA complex can strongly inhibit the growth of C26 tumour cells by inducing apoptosis, inhibiting tumour angiogenesis and increasing the number of immune cells that infiltrate the tumour microenvironment. The obvious tumour regression and safety of this approach were observed in peritoneal metastasis and subcutaneous xenograft models. The antitumour effect of the liposome protamine mRNA complex was as good as that for a plasmid DNA complex, and demonstrated the potential for mRNA-based gene therapy.

Delivery of modified mRNA encoding vesicular stomatitis virus matrix protein for colon cancer gene therapy

Plasmid DNA based gene delivery has been widely utilized among both pre-clinical and clinical gene therapy studies. However, therapeutic efficiency is usually limited by the size and potential immune-stimulation issue of plasmid backbone. As an alternative form of genetic material, chemically modified messenger RNA (mRNA) provides a promising alternative to plasmid DNA. In this work, an in vitro transcription mRNA encoding vesicular stomatitis virus matrix protein (VSVMP) was delivered by a cationic liposome–protamine complex, resulting in high mRNA transporting and expression efficiency. The liposome–protamine complex delivered VSVMP mRNA strongly inhibits the growth of C26 tumor cells through inducing apoptosis, while obvious tumor regressions were achieved on both abdominal cavity metastatic and subcutaneous xenograft models in vivo with high safety. Our results also demonstrated that the liposome–protamine–mRNA complex was as potent as its plasmid DNA counterpart, showing strong potential in further colon cancer therapy.

On the morphological, structural and electrochemical properties of entangled Cu-filled carbon nano-onions

In this work we demonstrate an advanced chemical vapour synthesis approach in which the synthesis of Cu-filled carbon nano-onions (CNOs) is achieved by direct sublimation and pyrolysis of a not previously used precursor, namely chloro(1,5-cyclooctadiene)copper(I) dimer. The cross-sectional morphology and filling-ratio of the as grown CNOs were characterized by detailed transmission electron microscopy (TEM), high resolution TEM analyses, Fourier transform and lattice profile analyses. The structural graphitic arrangement and electronic properties of the CNOs were then investigated by means of X-ray diffraction and absorption spectroscopy. The electrochemical impedance spectroscopy and cyclic voltammetry of presented structures were also investigated and reveal a high electrical resistance. Finally the electrochemical performances of this type of CNOs were compared with those of another type of CNOs filled with different metal-carbide materials.

Delivery of interleukin-22 binding protein (IL-22BP) gene by cationic micelle for colon cancer gene therapy

Gene therapy has provided an alternative strategy for cancer therapy. As an important cytokine, interleukin-22 (IL-22) is not only critical in reinforcing innate immune defenses and tissue regeneration, but also involved in the initial establishment of tumors. A soluble-secreted receptor of the cytokine IL-22, IL-22 binding protein (IL-22BP), binds IL-22 and prevents its binding to the functional transmembrane receptor IL-22R1 complex, inhibiting IL-22-based intracellular cancer proliferation signal. In this work, a novel IL-22BP-based cancer gene therapy strategy was reported for the first time. It was established by delivering IL-22BP gene with a newly developed non-viral gene vector DMP. The DMP cationic micelles were prepared by modifying monomethoxy poly(ethylene glycol)-poly(e-caprolactone) with DOTAP lipid through self-assembling. The anti-cancer efficacy of the DMP/IL-22BP complex was studied on a colon cancer model by intraperitoneal administration. Our results demonstrated that the secretory expressed IL-22BP cytokine effectively inhibited cancer growth both in vitro and in vivo. Multiple anti-cancer mechanisms including IL-22 blocking, apoptosis inducing, lymphocyte infiltration and angiogenesis inhibition were indicated to be involved while no pathology changes were observed in healthy tissues. These results suggest the DMP/IL-22BP complex to be a potential candidate for cancer gene therapy.

Local and Systemic Delivery of Interleukin-12 Gene by Cationic Micelles for Cancer Immunogene Therapy

Immunogene therapy is an alternative strategy for cancer gene therapy. By stimulating the activities of immune cells in the tumor microenvironment, the genetic materials boost the immune response to attack cancer cells resulting in therapeutic effects. Interleukin-12 is an important regulator with great potential in modulating both innate and adaptive immunities. Here, a cancer immunogene therapy strategy was established and evaluated by delivering the IL-12 gene with a novel non-viral gene vector DMP. The DMP cationic micelles were prepared by modifying monomethoxy poly(ethylene glycol)-poly(ε-caprolactone) with the DOTAP lipid via self-assembly. The anti-cancer efficacy of the DMP/IL-12 complex was studied on multiple murine cancer models via both local and systemic administration. Our results demonstrated that the secretory expressed IL-12 cytokine effectively enhanced lymphocytes activities resulting in strong inhibition of cancer cell growth in vitro. Meanwhile, there were obvious tumor regressions achieved in tumor models of C26 colon carcinoma and LL/2 lung cancer in vivo. Multiple anti-cancer mechanisms including T cell infiltration, TNF-α secretion, apoptosis induction and angiogenesis inhibition are involved; no pathology changes were observed in healthy tissues. These results suggest that the DMP/IL-12 complex is a potential candidate for cancer immunogene therapy.

Induction and Amelioration of Methotrexate-Induced Gastrointestinal Toxicity are Related to Immune Response and Gut Microbiota

As a widely used anticancer and immunosuppressive agent, methotrexate (MTX) can induce multiple adverse drug reactions (ADRs), such as gastrointestinal toxicity, the mechanisms are poorly understood. Gut microbiota has been widely reported to be associated with the onset of multiple diseases as well as treatment outcomes of different drugs. In this study, mucosal injury was observed in MTX-treated mice, leading to significant changes in macrophages (i.e., M1/M2 ratio, P < 0.05) but not in dendritic cells. Moreover, the population, diversity and principal components of the gut microbiota in mice were dramatically altered after MTX treatment in a time-dependent manner, and Bacteroidales exhibited the most distinct variation among all the taxa (P < 0.05). Bacteroides fragilis was significantly decreased with MTX treatment (P < 0.01) and tended to decrease proportionately with increasing macrophage density. Gavage of mice with B. fragilis ameliorated MTX-induced inflammatory reactions and modulate macrophage polarization. In conclusion, our results delineate a strong impact of the gut microbiota on MTX-induced intestinal mucositis and provide a potential method for the prevention of such ADRs.

In vitro and in vivo characterization of a novel long-acting GLP-1 receptor agonist, exendin-4–Fc fusion protein

Exendin-4 (Ex-4), one of the important glucagon-like peptide-1 receptor (GLP-1R) agonists, has proven to be an effective antidiabetic agent for type 2 diabetes (T2D). However, its therapeutic potential is limited due to its short half-life (t1/2), which is subcutaneously administered twice daily. The aim of this study is to develop a safe, efficacious and longer acting potential anti-diabetic agent. The bioactivity of (Ex-4)2–Fc was examined in U2OS cells and we used molecular docking software to test the stability of the (Ex-4)2–Fc/GLP-1 receptor complexes. The pharmacokinetics of (Ex-4)2–Fc was studied in male Sprague-Dawley (SD) rats and the pharmacodynamics was assessed in various mouse models. The bioactivity of (Ex-4)2–Fc was over 10-fold higher than that of Ex-4–Fc in vitro and the stability of the (Ex-4)2–Fc/GLP-1 receptor complexes was better than that of the Ex-4–Fc/GLP-1 receptor complexes. The pharmacokinetics of (Ex-4)2–Fc showed that it had a more than 200-fold prolongation in plasma half-life compared with that of Ex-4, which was 122 h and 0.56 h, respectively. The treatment with (Ex-4)2–Fc every 6 days, compared to the vehicle control, effectively reduced body weight, decreased food intake, and improved glucose metabolism in high-fat-diet induced obesity (DIO) mice, leptin-deficient ob/ob and leptin receptor-defective db/db mice. Our studies suggest that (Ex-4)2–Fc retains the bioactivity of the GLP-1 receptor agonist with a prolonged half-life in vivo, providing a promising drug candidate for the treatment of type 2 diabetes.