Fansheng Kong

Transferrin-PEG-PE modified dexamethasone conjugated cationic lipid carrier mediated gene delivery system for tumor-targeted transfection

Background The main barriers to non-viral gene delivery include cellular and nuclear membranes. As such, the aim of this study was to develop a type of vector that can target cells through receptor-mediated pathways and by using nuclear localization signal (NLS) to increase the nuclear uptake of genetic materials. Methods A dexamethasone (Dexa)-conjugated lipid was synthesized as the material of the solid lipid nanoparticles (SLNs), and transferrin (Tf) was linked onto polyethylene glycol-phosphatidylethanolamine (PEG-PE) to obtain Tf-PEG-PE ligands for the surface modification of the carriers. The in vitro transfection efficiency of the novel modified vectors was evaluated in human hepatoma carcinoma cell lines, and in vivo effects were observed in an animal model. Results Tf-PEG-PE modified SLNs/enhanced green fluorescence protein plasmid (pEGFP) had a particle size of 222 nm and a gene loading quantity of 90%. Tf-PEG-PE-modified SLNs/pEGFP (Tf-SLNs/pEGFP) displayed remarkably higher transfection efficiency than non-modified SLNs/pEGFP and the vectors not containing Dexa, both in vitro and in vivo. Conclusion It can be concluded that Tf and Dexa could function as an excellent active targeting ligand to improve the cell targeting and nuclear targeting ability of the carriers, and the resulting nanomedicine could be a promising active targeting drug/gene delivery system.

Mannosylated liposomes for targeted gene delivery

Background Liposomes can be modified with different ligands to control their biological properties, such as longevity, targeting ability, and intracellular penetration, in a desired fashion. The aim of this study was to modify liposomes with a novel mannosylated polyethylene glycol-phosphatidylethanolamine (M-PEG-PE) ligand to achieve active targeted gene delivery. Methods Rat Kupffer cells were isolated and used as model cells for in vitro evaluation of cytotoxicity and transfection efficiency. The modified liposomes were intravenously injected into the rats, and Kupffer cells were isolated and analyzed by flow cytometry for in vivo gene delivery and expression. Results The M-PEG-PE-modified liposome-enhanced green fluorescence protein plasmid (M-PEG-PE-Lipo-pEGFP) complexes had a particle size of 237 nm and a loading efficiency of 90%. The M-PEG-PE-Lipo-pEGFP complexes displayed remarkably higher transfection efficiency than unmodified Lipo-pEGFP, both in vitro (51%–30%) and in vivo (43%–27%). Conclusion M-PEG-PE could function as an excellent active targeting ligand, and M-PEG-PE-modified liposomes could be promising active targeted drug delivery vectors.

Delivery of baicalein and paclitaxel using self-assembled nanoparticles: synergistic antitumor effect in vitro and in vivo.

Purpose Combination anticancer therapy is promising to generate synergistic anticancer effects to maximize the treatment effect and overcome multidrug resistance. The aim of the study reported here was to develop multifunctional, dual-ligand, modified, self-assembled nanoparticles (NPs) for the combination delivery of baicalein (BCL) and paclitaxel (PTX) prodrugs. Methods Prodrug of PTX and prodrug of BCL, containing dual-targeted ligands of folate (FA) and hyaluronic acid (HA), were synthesized. Multifunctional self-assembled NPs for combination delivery of PTX prodrug and BCL prodrug (PTX-BCL) were prepared and the synergistic antitumor effect was evaluated in vitro and in vivo. The in vitro transfection efficiency of the novel modified vectors was evaluated in human lung cancer A549 cells and drug-resistant lung cancer A549/PTX cells. The in vivo antitumor efficiency and systemic toxicity of different formulations were further investigated in mice bearing A549/PTX drug-resistant human lung cancer xenografts. Results The size of the PTX-BCL NPs was approximately 90 nm, with a positive zeta potential of +3.3. The PTX-BCL NPs displayed remarkably better antitumor activity over a wide range of drug concentrations, and showed an obvious synergism effect with CI50 values of 0.707 and 0.513, indicating that double-ligand modification and the co-delivery of PTX and BCL prodrugs with self-assembled NPs had remarkable superiority over other formulations. Conclusion The prepared PTX-BCL NP drug-delivery system was proven efficient by its targeting of drug-resistant human lung cancer cells and delivering of BCL and PTX prodrugs. Enhanced synergistic anticancer effects were achieved by PTX-BCL NPs, and multidrug resistance of PTX was overcome by this promising targeted nanomedicine.

Comparison of two kinds of nanomedicine for targeted gene therapy: premodified or postmodified gene delivery systems.

Background The applications of ligand-polyethylene glycol (PEG)-modified nanocarriers have now emerged, as well as recognized strategies to provide the vectors with active targeting properties. In this research, premodification and postmodification were compared using the same ligand, ie, a novel conjugated mannan-containing PEG and L-α-phosphatidylethanolamine (PE). Methods Premodified and postmodified solid lipid nanoparticles were prepared and the characteristics of the two kinds of vehicles were evaluated. The modified vectors were then administered intravenously to rats and the in vivo targeting behavior of the complexes was investigated in liver macrophages. Results By carefully formulating the carriers with an optimal ratio of mannan-containing PEG-PE, postmodified vehicles displayed more efficient gene expression in rat Kupffer cells both in vitro and in vivo. Conclusion Postmodified gene carriers are superior to premodified gene vectors, although the latter is also promising for targeted gene delivery. This discovery could guide our future research.

Serum microRNA155 is increased in patients with acute graft-versus-host disease.

To explore the clinical relevance of three lymphocyte‐related serum microRNAs (miR‐155, miR‐214, and miR‐326) to the pathogenesis of graft‐versus‐host disease (GVHD), 64 subjects who received allogeneic peripheral blood stem cell transplantation (allo‐PBSCT) were recruited in this study, of whom 19 subjects did not develop GVHD, 25 subjects were diagnosed with acute GVHD (aGVHD), and 20 subjects were diagnosed with chronic GVHD (cGVHD). Serum miRNAs were determined by real‐time RT‐PCR. Expression level of miRNAs and the expression signatures of miRNAs as a panel were analyzed among the three groups. The expression level of miR‐214 and miR‐326 showed no significant difference between GVHD and non‐GVHD groups. However, miR‐155 was significantly up‐regulated in GVHD patients. There was a correlation between the level of miR‐155 and the severity of aGVHD. Moreover, serum IFN‐gamma, IL‐17, and IL‐9 levels were higher in aGVHD patients with high miR‐155. In conclusion, the expression level of lymphocyte‐related miR‐155 in serum was significantly increased in aGVHD patients. The miR‐155 may be considered as a potential targeted therapy for aGVHD patients.

Mannan-Modified PLGA Nanoparticles for Targeted Gene Delivery

The studies of targeted gene delivery nanocarriers have gained increasing attention during the past decades. In this study, mannan modified DNA loaded bioadhesive PLGA nanoparticles (MAN-DNA-NPs) were investigated for targeted gene delivery to the Kupffer cells (KCs). Bioadhesive PLGA nanoparticles were prepared and subsequently bound with pEGFP. Following the coupling of the mannan-based PE-grafted ligands (MAN-PE) with the DNA-NPs, the MAN-DNA-NPs were delivered intravenously to rats. The transfection efficiency was determined from the isolated KCs and flow cytometry was applied for the quantitation of gene expression after 48 h post transfection. The size of the MAN-DNA-NPs was found to be around 190 nm and the Zeta potential was determined to be −15.46mV. The pEGFP binding capacity of MAN-DNA-NPs was (88.9±5.8)% and the in vitro release profiles of the MAN-DNA-NPs follow the Higuchi model. When compared with non-modified DNA-NPs and Lipofectamine 2000-DNA, MAN-DNA-NPs produced the highest gene expressions, especially in vivo. The in vivo data from flow cytometry analysis showed that MAN-DNA-NPs displayed a remarkably higher transfection efficiency (39%) than non-modified DNA-NPs (25%) and Lipofectamine 2000-DNA (23%) in KCs. The results illustrate that MAN-DNA-NPs have the ability to target liver KCs and could function as promising active targeting drug delivery vectors.

Novel mannan-PEG-PE modified bioadhesive PLGA nanoparticles for targeted gene delivery

Purpose. Biodegradable polymeric nanoparticles have been used frequently as gene delivery vehicles. The aim of this study is to modify bioadhesive PLGA nanoparticles with novel synthetic mannan-PEG-PE (MN-PEG-PE) to obtain active targeted gene delivery system. Methods. Mannan-PEG-PE ligands were synthesized and modified onto the NPs/pEGFP complexes. The modification rate was optimized, and the characteristics of the vehicle were evaluated. Then, the modified vectors were intravenous delivered to rats, and in vivo targeting behavior of MN-PEG-PE modified PLGA nanoparticles/pEGFP complexes (MN-PEG-PENPs/ pEGFP) in liver macrophages was investigated. Results. MN-PEG-PE-NPs/pEGFP displayed remarkably higher transfection efficiencies than nonmodified NPs/pEGFP both in vitro and in vivo. Conclusions. Mannan containing targeting ligands could significantly improve the transfection efficiency of the carriers. MN-PEG-PEmodified vectors very useful in targeted gene delivery.

Clinical observations on intensive immunosuppressive therapy combined with umbilical cord blood support for the treatment of severe aplastic anemia

ObjectiveTo evaluate the efficacy of enhanced, intensive, immuno-suppressive therapy with umbilical cord blood support for severe aplastic anemia (SAA).MethodsA total of 25 patients with SAA received enhanced, intensive, immuno-suppressive therapy and a cord blood transfusion. Therapy protocol: Anti-thymocyte globulin (ATG) 2.5 mg/(kg•d) × 5d; Cyclophosphamide 50 mg/(kg•d) × 2d; cyclosporin A (CsA) maintenance therapy.Result25 patients were enrolled. 18 underwent a complete recovery, 4 made significant improvements, 1 did not respond, and 2 died. Therefore, the efficacy rate was 88%. The median follow-up time was 35 months (range 13-47 months), and the 3-year overall survival rate was 92%. Patients rapidly achieved reconstitution of hematopoiesis. The median time to neutrophil ANC > 0.5 × 109/L was 18 days (range 8-36), platelets >20 × 109/L was 34 days (range 12-123), and Hb > 100 g/L 95 dyas (range 35-173).ConclusionEnhanced, intensive, immuno-suppressive therapy with umbilical cord blood support may be an effective option for SAA therapy.

A promising targeted gene delivery system: Folate-modified dexamethasone-conjugated solid lipid nanoparticles

Abstract Context: Non-viral gene delivery could deliver drugs/genes through cellular membranes and nuclear membranes by some modification of materials. Objective: This study develops a kind of vector to target the cells through receptor-mediated pathways. Nuclear localization signal (NLS) was also used to increase the nuclear uptake of genetic materials. Materials and methods: A lipid containing dexamethasone (Dexa) was synthesized as the material of the preparation of solid lipid nanoparticles (SLNs) and folate (Fa)-conjugated PEG-PE (Fa-PEG-PE) ligands were used to modify the SLNs. The in vitro cytotoxicity of the carriers at various concentrations (10, 20, 50, 100, and 200 μg/ml) were evaluated in KB human carcinoma cells (KB cells). In vivo transfection efficiency of the novel modified vectors was evaluated in disseminated peritoneal tumors on mice bearing KB cells. Results: Fa-PEG-PE modified SLNs/enhanced green fluorescence protein plasmid (pEGFP) has a particle size of 258 nm, and the gene loading quantity of the vector was 90%. The in vitro cytotoxicity of Fa-PEG-PE-modified SLNs/pEGFP (Fa-SLNs/pEGFP) was low (cell viabilities were between 80% and 100% compared with controls). Fa-SLNs/pEGFP displayed remarkably higher transfection efficiency (40%) than non-modified SLNs/pEGFP (24%) and the vectors not containing Dexa (30%) in vivo. Conclusion: The results demonstrate that Fa and Dexa could function as excellent active targeting ligands to improve the cell targeting and nuclear targeting ability of the carriers and the resulting vectors could be promising active targeting drug/gene delivery systems.

Assessment of the use of immunosuppressants combined with cord blood for severe aplastic anemia

BACKGROUND The objective of this study was two-fold: 1) to investigate the changes of cytokines concentration in relation to severe aplastic anemia (SAA) when treated with immunosuppressants combined with cord blood (IS + CBI). and 2) to assess the curative effect of umbilical cord blood chimerism engraftment. METHODS We selected 43 patients with SAA all treated with IS + CBI (newly diagnosed group). Among them, a total of 33 patients were treated effectively (effective group) while 10 cases were treated invalidly (invalid group). An additional 20 healthy individuals were selected as control (control group). The expression levels of IL-17, IL-22 and other cytokines in each group were detected by ELISA. The engraftment of cord blood stem cells was detected by using short tandem repeat-polymerase chain reaction (STR-PCR). RESULTS 1. IL-17, IL-22 and other cytokines expressions in the newly diagnosed group were significantly higher than in the control group. 2. After six months, the levels in the effective group were significantly lower than pre-therapy levels (P < 0.05). The levels in the invalid group did not differ to those observed prior treatment. 3. After one and three months of treatment, a small amount of engraftment was found in the effective group. However, after six months, transplant rejection was observed in all patients. No effective engraftment was observed in the invalid group. CONCLUSION 1) Th17 and Th22 producing cells in SAA patients significantly increased indicating a positive correlation between these biomarkers and the progression of SAA. 2) During the IS + CBI treatment the maintenance of a normal hematopoietic function depended on immunesup-pressants. Early umbilical cord blood chimerism engraftment may promote hematopoietic recovery.BACKGROUND Pollen allergy is a growing global health issue. While airborne pollen counts are reported daily in several countries, such information is lacking in Thailand. OBJECTIVE This study aimed to survey airborne pollens at five sites in Bangkok, comparing data with the previous study performed 35 years ago in 1980. METHODS Sample collection was done using the ROTOROD® sampler by exposing the rods for one hour each day twice a week from May 2012-April 2013. RESULTS Overall, we found that the average pollen count was relatively high throughout the year, at an average of 242 grains/m3. The highest peak was found in September (700 grains/m3). Interestingly, we found that the pollen count was noticeably lower in 2012-2013 when compared to the 1980 study. We also observed the approximate shift of pollen peaks about one to two months earlier in the 2012-2013 study. However, the major groups of airborne pollens did not change significantly. Grass, sedge, amaranthus pollens and fern spores still dominated. The unidentified pollen group was the only group with a higher pollen count when compared to the previous study.