γ-Ray-Radiation-Scissioned Chitosan as a Gene Carrier and Its Improved in vitro Gene Transfection Performance

Chitosan （CS） is expected to be an ideal gene carrier for its high biosafety. In this work, CS with low molecular weight were prepared through the γ-ray radiation on the acetic acid solution of CS. The CS chains were scissioned under the γ-ray radiation, and the molecu- lar weight （MW） of CS decreased with the absorbed dose. When the absorbed dose was above 30 kGy, the molecular weight of CS decreased about an order of magnitude. The γ-ray-radiation-scissioned CS can effectively bind with plasmid （pEGFP） through complex coacervation method, forming pEGFP/γ-ray-radiation-scissioned CS complex particles with a size of 200-300 nm. The complex particles have good stability and little cytotoxicity. The in vitro gene transfection efficiencies of the pEGFP/γ-ray-radiation-scissioned CS complex particles were investigated by fluorescence microscope and flow cytometry. The results showed that the gene vectors using γ-ray-radiation-scissioned CS as the carrier will possess better gene transfection efficiency than those using natural high-MW CS as the carrier. The higher the absorbed dose, the smaller the MW of CS and the better transfection efficiency of the corresponding gene vector. This work provides a green and simple method on the preparation of CS-based gene vectors with high efficiency and biosafety.

BASIC FIBROBLAST GROWTH FACTOR GENE TRANSFECTION TO ENHANCE THE REPAIR OF AVASCULAR NECROSIS OFTHE FEMORAL HEAD

Objective To explore a new method for the therapy of avascular necrosis of the femoral head. Method The recombinant plasmid pCD-rbFGF was mixed with collagen and was implanted in the necrotic femoral head. Expression of basic fibroblast growth factor (bFGF) was examined by RT-PCR and immunohistochemical method. Re-pair of the femoral head was observed by histological and histomorphometric analysis. Result Expression of bFGF was detected in the femoral head transfected with bFGF gene, indicating significant increase of angiogenesis 2 weeks after gene transfection and increased new bone formation 8 weeks after gene transfection on histom-orphometric analysis (P< 0.01). Conclusion Transfection of bFGF gene enhances bone tissue angiogenesis. Repair in osteonecrosis would be accelerated accordingly.

Ultrasound-targeted cationic microbubble-mediated gene transfection and inhibition of retinal neovascularization

AIM:To investigate whether ultrasound-targeted cationic microbubbles(CMBs)destruction could deliver endostatingreen fluorescent protein(GFP)plasmids efficiently to the human retinal endothelial cells(HRECs)and inhibit retinal neovascularization in mice.METHODS:CMBs were prepared and the presentation of GFP reporter was confirmed by flow cytometry and laser confocal microscopy.Experiments assessing HRECs migration and vascular formation were per formed to evaluate gene therapy’s efficiency in vitro.A mouse model of oxygen-induced retinopathy was employed and the expression of Bcl-xl,Bcl-2,vascular endothelial growth factor(VEGF)and endostatin in the retina of mice were determined by Western blotting and quantitative polymerase chain reaction(q PCR).The expression of endostatin-GFP in the retina was examined by laser confocal microscopy at 5,14,and 28 d after treatment.RESULTS:The gene expression of endostatin was the highest in the group of the CMBs.Besides,the inhibition and antiangiogenesis effect of the migration and development of HRECs were improved following treatment with CMBs compared with the other groups in vitro.In vivo,retinal neovascularization was significantly inhibited and the fluorescence intensity of endostatin-GFP in the mouse retina was importantly higher in the group of CMBs than that in other groups.CONCLUSION:The research illustrates ultrasoundtargeted CMBs destruction possessed distinct effect on the inhibition of the vascular formation and the development of retinal neovascularization both in vitro and in vivo.

Brain-derived neurotrophic factor gene transfection promotes neuronal repair and neurite regeneration after diffuse axonal injury

This study sought to assess the potential of brain-derived neurotrophic factor （BDNF） to promote neuronal repair and regeneration in rats with diffuse axonal injury, and to examine the accompanying neurobiological changes. BDNF gene transfection reduced the severity of the pathological changes associated with diffuse axonal injury in cortical neurons of the frontal lobe and increased neurofilament protein expression. These findings demonstrate that BDNF can effectively promote neuronal repair and neurite regeneration after diffuse axonal injury.

Protection of rat islet viability following heme oxygenase-1 gene transfection via adenoviral vector in vitro

Objective： To investigate the effect of Heme oxygenase-1 （HO-1） gene transfection on the viability of cultured rat islets, and to explore the potential value of HO-1 gene in islet transplantation. Methods：Recombinant adenovirus vector containing human HO-1 gene（Ad-HO-1 ） or enhanced green fluorescent protein gene（Ad-EGFP） was generated by using AdEasy system respectively. The rat islets were transfected with Ad-HO-1, Ad-EGFP or blank vector and then cultured for 7 days. Transfection was confirmed by expression of EGFP and human HO-1 protein detected by fluorescence photographs and western blot, respectively. The insulin release upon different concentration of glucose stimulation was detected using insulin radioimmunoassay kit, and stimulation index（SI） was calculated. Glucose-stimulated insulin release was used ＇to assess islet viability. Results：Adenovirus vector successfully transferred HO-1 gene to rat islet cells in vitro, and the insulin release upon high level of glucose stimulation and stimulation index （SI） of Ad-HO-1-infected islets were significantly higher than those of Ad-EGFP-infected islets and control islets （P 〈 0.05）. Conclusion： Adenovirus-mediated HO-1 gene transfection is a feasible strategy to confer cytoprotection and therefore protect the viability of cultured rat islets.

EFFECTS OF CARBOXYMETHLY DEXTRAN MAGNETIC NANOPARTICLES CARRIER SYSTEM ASSOCIATED WITH EXTERNAL MAGNETIC FIELDS ON KILLING TUMOR CELLS AND GENE TRANSFECTION

Objective: To investigate the preparation of the carboxymethly dextran iron oxide magnetic nanoparticles (CDMN) and the effects of CDMN carrier system associated with external magnetic fields on killing tumor cells and gene transfection in vitro. Methods: Epirubicin-CDMN (EPI-CDMN) and green fluorescent protein (GFP) plasmid-CDMN (GFP-CDMN) were prepared by the oxidation-reduction procedure and their characters were detected, respectively. The effects of EPI-CDMN associated with external pulsed electromagnetic fields (PEMFs) (10 mT) on killing human bladder cancer BIU-87 cells were studied by MTT assay and Annexin-V/PI double-labeled flow cytometry technique, respectively. And the transfection efficiency of GFP when CDMN were used as gene carrier associated with the external magnetic fields was evaluated under fluorescence microscope in vitro. Results: The diameter of EPI-CDMN and GFP-CDMN were about 8~10 nm and 5~9 nm, respectively, and saturation magnetization were 0.22 emu/g and 0.26 emu/g, respectively. EPI-CDMN associated with PEMFs could significantly inhibit the proliferation of BIU-87 cells and induce cells apoptosis, the growth inhibitory rate and apoptosis rate were (21.82±3.18)% and (16.79±3.37)%, respectively. The transfection efficiency of GFP-CDMN combined with PEMFs was significant higher than that of GFP-CDMN without PEMFs [(45.70±4.32)% vs (35.85±2.16)%, P<0.05]. Conclusion: It seemed that EPI-CDMN associated with external magnetic fields could significantly killed human bladder cancer BIU-87 cells and CDMN could effectively transfer GFP gene into tumors cells with the help of external magnetic fields which provided experimental basis for the magnetic targeting therapy of tumor.

Editor's Choice—Adenovirus-mediated gene transfection of stem cells

Neural stem cells transplantation plays an important role in repair and cell replacement therapy for nervous system degenerative diseases. However, the self-repair effects are minimal because of a limited absolute number, as well as the local microenvironment, post-transplantation. A combined treatment utilizing stem cell transplantation and gone therapy can exert a dual effect involving stem cells and neurotrophic factors. The adenovirus carrier is

Gene Transfection Mediated by Ultrasound and Pluronic P85 in HepG2 Cells

In order to assess whether gene transfection could be mediated by ultrasound in association with P85 and find the appropriate parameters of ultrasound irradiation, the effects of ultrasound with or without P85 on gene transfection of HepG2 cells were examined. The HepG2 cells were irra- diated by ultrasound at 1 MHz, 0.4-2.0 W/cm2 and 50% duty cycle with plasmid encoding enhanced green fluorescent protein （EGFP） as a report gene. Forty-eight h later, the expression of EGFP was detected under the fluorescence microscopy. Transfection efficacy was quantitatively assessed by flow cytometry, and cell viability was evaluated by trypan blue exclusion. The results showed that the transfection efficacy was increased with the increases in ultrasound output power and the ideal transfection efficacy was achieved in HepG2 cells irradiated by ultrasound at 0.8 W/cm2 for 30 s. The transfection efficacy in ulstrasound＋P85 group was three times higher than in single ultrasound group [（17.63±1.07）% vs （5.57±0.56）%, P〈0.05]. The cell viability was about 81% and 62% in ultrasound group and ultrasound＋P85 group respectively. It was concluded that ultrasound in combination with P85 could mediate the gene transfection of HepG2 cells, ideal transfection efficacy was achieved by ultrasound irradiation at 0.8 W/cm2 for 30 s, and P85 could somewhat increase the damage to cells caused by ultrasound.

Cationic Liposome-mediated bcl-xl Gene Transfection into Human Keratocytes

The efficiency and safe range of LipofectamineTM2000 (LF2000)/bcl-xl applied in human keratocytes, the optimal ratio of LF2000/bcl-xl and the bcl-xl gene expression in human keratocytes were investiaged. By using trypan-blue staining, the effects of LF2000 and bcl-xl on the survival rate of the cultured human keratocytes were measured respectively. By using semi-quantitative RT-PCR, the efficiency and the expression of LF2000-mediated bcl-xl transfection into keratocytes were examined. The results showed that the survival rate of human keratocytes had no signficant change in the presence of LF2000 (20 μg/ml) or bcl-xl (10 μg/ml) for 24 h. LF2000 could effectively mediate the transfection of exogenous gene bcl-x1 into human keratocytes. The best transfection efficiency could be obtained when the ratio of bcl-xl/LF2000 was 1:8. One day after transfection, the positive cells for bcl-x1 could be detectable, and the positive rate reached the peak on the post-transfection day 3 (48.3 %), then gradually decreased. Fifteen days after transfection, there were few positive cells. It was suggested that LF2000 could effectively transfer the exogenous gene bcl-xl into human keratocytes without obvious toxicity during a concentration range. LF2000/bcl-xl may be likely to play an important role in gene therapy of human keratocytes.

Combined Pluronic P85- and Ultrasound Contrast Agents-mediated Gene Transfection to HepG2 Cells

This study examined the effect of P85 （a pluronic block copolymer） and microbubble （MB） ultrasound contrast agents under ultrasound irradiation on gene transfection and expression. The pEGFP plasmids that can encode enhanced green fluorescent protein （pEGFP） served as a report gene and were mixed with different concentrations of MB/0.05% （w/v） P85. Then the plasmids were transfected into human hepatoma G2 （HepG2） cells. The HepG2 cells treated with MB/P85 or without treatment were exposed to ultrasound （US parameters： 1 MHz, 1.0 W/cm2, 20 s, 20% duty cycle）. Twenty-four hours later, the transfection efficiency was assessed by fluorescence microscopy and fluo-rescence activated cell sorting （FACS） analysis. The cell viability was evaluated by Trypan blue exclusion test. The results showed that the gene transfection efficiency in HepG2 cells under ultrasound irradiation was significantly higher than that without ultrasound irradiation. HepG2 cells in the MB or P85 group in the absence of ultrasound expressed less amount of green fluorescent protein. The expression efficiency reached （22.14±3.06）% and the survival rate was as high as （55.73±3.32）% in the 30% MB plus P85 group. It was concluded that MB and P85 in the presence of ultrasound can enhance gene transfection and expression.

RAT GDNF GENE TRANSFECTION AND EXPRESSION OF ITS mRNA AND PROTEIN IN SCHWANN CELLS

Objective To investigate the possibility of the transfection of glial-cell line derived neurotro-phic factor (GDNF) gene into Schwann cells (SCs). Methods SCs cultures from sciatic nerves of neonatal rats were established. A recombinant retrovirus vector containing GDNF gene was constructed and transferred into SCs. Expression levels of GDNF mRNA and protein were respectively identified with reverse transcriptase-polymerase chain reaction (RT-PCR) and immunocytochemistry. Determination of GDNF synthesis rates from Retro. pLNCX2-GDNF-transduced SCs (GDNF-SCs) in vitro by enzyme-linked immunoassay sensitive assay (ELISA). Biololgical activity of conditioned medium from GENF-SCs was analysed by co-culture with rat motoneurons. Results Transfection of GDNF gene into SCs lead to significantly enhanced expression of GDNF mRNA and protein. The rate of GDNF secreted by GDNF-SCs was also enhanced(5. 1-fold) ,and more motoneurons survived co-cultured with conditioned medium of GNDF-SCs than with that of normal SCs. Conclusion GNDF gene transfection may be a better way to graft SCs promoting regeneration and repairing demyelination in PNS and CNS.

Differentiation of Rabbit Bone Marrow Mesenchymal Stem Cells to Myogenic Cells and Expression of VEGF After Gene Transfection

Objectives To induce the differentiation of rabbit bone marrow mesenchymal stem cells （MSCs） to myogenic cells in vitro, and to investigate the expression of vascular endothelial growth factor （VEGF） gene in MSCs transfected by AdTrackCMV-VEGF165. Methods MSCs were isolated and purified from rabbit bone marrow by percoll （11）73 g/ml） and then cultured in low glucose DMEM with 10% FBS. AdTrackCMV-VEGF165 eukaryotic expression vector was constructed and transfected into the MSCs. After being incubated with 5-azacytidine （5- Aza）, the expression of troponin I in MSCs was assayed by immunohistochemistry and the expression of VEGF gene was identified by northern blot and western blot. The concentration of VEGF in the supernatant was measured by ELASA. Results MSCs were isolated and cultured successfully from rabbit bone marrow. The positive cTnI stain of some MSCs after the induction of 5-aza indicated that the cells were differentiated to myogenic cells. Northern blot and western blot showed that the expression of VEGF 165 mRNA was much higher in the hVEGF165 gene transfected cells than that of the control. The concentration of VEGF in the supernatant got to the peak 3-5 days after hVEGF165 gene transfection （1011- 1027 pg/ml） and decreased gradually thereafter, but still higher than that of control group or pAdTrackCMV group （349 pg/mLvs 116 pg/mL or 125pg/ml respectively, MSCs could be induced P〈 0.01）. Conclusions to differentiate to myogenic cells by 5-aza in vitro and could express VEGF by VEGF gene transfection.

Pillar[5]arene-modified peptide-guanidiniocarbonylpyrrol amphiphiles with gene transfection properties

Pillar[5]arene-modified amphiphilic peptides with varying numbers of guanidiniocarbonylpyrrol(GCP)moieties have been successfully synthesized,which can self-assemble to multivalent cationic superstructures in aqueous solutions.These assembled peptides can condense DNA into various compact multimolecular aggregates to achieve successful intracellular DNA delivery and demonstrate great potential for gene transfection.Transfection efficiencies of the self-assembled superstructures have been evaluated in vitro with He La and HEK 293T cells.We demonstrate that GCP moiety could enhance the cell transfection ability,owing to its excellent binding towards cytomembrane.It was also found that subtle structure difference in peptides 2 and 3 could result in distinct transfection efficacy,which makes it possible to gain an in-depth understanding of their structure-activity relationship.This work presents a good example of rational structural design in achieving effective gene transfection vectors.

Efficient gene transfection of suspension cells by highly branched poly(β-amino ester)

Suspension cells play a crucial role in many biological processes. However, compared to adherent cells, it is particularly challenging to introduce exogenous genes into suspension cells to regulate their biological functions with non-viral gene vectors, mainly due to the low cellular uptake and endosomal escape of polyplexes. Herein, to improve the interactions of polyplexes with cellular membranes, we design and synthesize highly branched poly(β-amino ester)(HPAE) via an “A2 + B4 + C2” Michael addition strategy.Results show that branching significantly increases DNA condensation of HPAE, cellular uptake and endosomal escape of HPAE/DNA polyplexes. In mast cells(MCs), HPAE exhibits up to 80-fold higher gene transfection efficiency compared to the corresponding linear poly(β-amino ester)(LPAE) and the leading commercial gene transfection reagents PEI25k, jetPEI, and Lipofectamine 3000, without causing obvious cytotoxicity. Our study establishes a reliable non-viral platform for efficient gene transfection of suspension cells.

Highly branched poly(β-amino ester)s with narrow molecular weight distribution: Fractionation and gene transfection activity

Highly branched poly(β-amino ester)s(HPAEs) have shown their great promise in gene delivery. However, their broad molecular weight distribution(MWD) poses an additional challenge to the mechanistic understanding of the influence of molecular weight(MW) on their gene transfection activity. Using a stepwise precipitation strategy, HPAEs were fractionated. It is shown that MW has a significant effect on the transfection activity and cytotoxicity of HPAEs. The intermediate MW mediates higher transfection efficiency while maintaining high cell viability. Mechanistic studies show that the intermediate MW confers stronger DNA binding affinity to HPAEs, leading to the formulation of polyplexes with a relatively smaller size and more positive zeta potential. This study not only suggests a simple strategy to fractionate HPAEs with narrow MWD but also provides new insights into understanding the structure-property relationship, which would facilitate the clinical translation of HPAEs in gene therapy.

Transfection of the Human Sodium/Iodide Symporter(NIS) Gene with Liposomes and the Expression of the NIS Protein in Human Lung A549 Cancer Cells

OBJECTIVE To examine the possibility of human sodium iodide symporter （hNIS） protein expression in lung cancer cells. METHODS Human lung A549 cancer cells were thawed and cultured in vitro. The cells were divided into an experimental group transfected with a recombinant pcDNA3-hNIS plasmid and a control group transfected only with a pcDNA3 plasmid. The recombinant plasmid vector encoding the hNIS gene （pcDNA3-hNIS） was amplified, purified and identified. The hNIS gene was followed by DNA sequencing. A Western blot and an immunohistochemical assay were applied to detect the hNIS protein expression in the transfected human lung A549 cancer cells. RESULTS Restriction enzyme digestion and DNA sequencing results showed the size and direction of the inserted gene in the recombinant pcD- NA3-hNIS plasmid was correct. The Western blot method and immunohistochemical analysis showed a positive NIS protein expression in the experimental group. The NIS protein was detected mainly in the cell membranes showing a positive rate up to 70.6% with no expression of the NIS protein in the control group. There was a significant difference between two groups （P=0.000）. CONCLUSION The hNIS gene was transfected effectively into human lung A549 cancer cells mediated by Lipofectamine 2000, and was expressed with its protein in vitro.

Vascular endothelial growth factor gene transfection to enhance the repair of avascular necrosis of the femoral head of rabbit

Objective To explore a new method for the therapy of avascular necrosis of the femoral head. Methods The recombinant plasmid pCD-hVEGF 165 was mixed with collagen and was implanted in the necrotic femoral head. The expression of vascular endothelial growth factor (VEGF) was examined by RNA dot hybridization and immunohistochemical techniques. Repair of the femoral head was observed by histological and histomorphometric analysis.Results The expression of VEGF was detected in the femoral head transfected with the VEGF gene. The femoral head transfected with the VEGF gene showed a significant increase in angiogenesis 2 and 4 weeks after gene transfection and a significant increase in bone formation 6 and 8 weeks after gene transfection on histomorphometric analysis ( P <0.01).Conclusions Transfection of the VEGF gene enhances bone tissue angiogenesis. Repair of osteonecrosis could be accelerated accordingly,thus providing a potential method for therapy of osteonecrosis.

Effect of vascular endothelial growth factor 165 gene transfection on bone defects and its mRNA expression in rabbits

Background Gene therapy has been a hot spot in repair of bone defects in recent years. This study aimed to construct a recombinant plasmid pcDNA3.1-VEGF165, and to observe the effect of vascular endothelial growth factor 165 （VEGF165） gene therapy on bone defects in rabbits. Methods Total RNA was extracted from rabbit bone tissues. VEGF165 cDNA fragment was prepared by reverse transcription and the gene was cloned by polymerase chain reaction （PCR）. Plasmid pMD18-T/VEGF165 combined with pcDNA3.1 was cloned to reconstruct pcDNA3.1-VEGF165 plasmid. Thirty New Zealand white rabbits weighing （2.50±0.13）kg were used to establish models of bone defects （1 cm in length） of the bilateral radii. The bone defects were repaired with absorbable gelatin sponge. After the operation, physiological sodium chloride solution was injected into the injured site in one of the forelegs of the rabbits as the control group, and pcDNA3.1-VEGF165 plasmid （0.2 ml, 200 ng） was injected into the opposite foreleg as the experiment groups. At weeks 1, 2, 4, 6, 8, and 12 after the treatments, the bones were examined by X-ray, and the specimens of the bone defects were collected, stained with HE, and observed under a light microscope. The expression of VEGF165 mRNA was examined by real-time quantitative polymerase chain reaction （RQ-PCR）. Results The pcDNA3.1-VEGF165 plasmid with a correct sequence was constructed successfully. Postoperative X-ray found no difference between the two groups at week 1. In the experiment group, callus and synostosis were observed after 2 weeks, and osteosis structure was normal at week 12; these phenomena occurred much later in the control group. In the experiment group, HE staining showed a large amount of newly formed blood vessels after 2 weeks, a number of bone trabeculae with osteoblasts proliferation at 4 weeks, and fresh bone cortex and reformed medullary cavity at 12 weeks; whereas in the control group these structures formed in later phases. The VEGF165 mRNA in the experiment group was expressed at a low level at week 1, reached the peak at weeks 3, and then decreased to a normal level after 6 weeks. Conclusions Local use of pcDNA3.1-VEGF165 plasmid at bone defects can upregulate the expression of VEGF165 and accelerate the formation of capillaries and the repair of bone defects. Angiogenesis and osteogenesis can be promoted by a combination of pcDNA3.1-VEGF165 and gelatin sponge.

Heat shock protein 70 gene transfection protects rat myocardium cell against anoxia-reoxygeneration injury

Background A number of studies suggest that the expression of heat shock protein 70 （HSP70） induced by heat stress are associated with protection against ischemia-reperfusion injury. But the protective effects may be contaminated by other factors in the same stress. This study was conducted to explore the protective role of HSP70 expression in acute myocardial anoxia/reoxygeneration （A/R） injury with a liposome-mediated gene transfer technique for the introduction of pCDNA HSP70 into the neonatal rat myocardial cells. In addition, heat shock stress cytoprotection was also investigated for comparison. Methods The cultured primary neonatal rat myocardiocytes with an acute myocardial A/R injury model and the HS-treated rat myocardiocyte model were used. Three-day cultured myocardiocytes were randomly divided into four groups （n=8）： control group, A/R group, HS＋A/R group and pCDNA HSP70 ＋A/R group. A liposome-coated HSP70 pCDNA plasmid was transfected into the primary neonatal rat myocardiocytes; HSP70 mRNA and its protein were confirmed by reverse transcriptase polymerase chain reaction （RT-PCR） and Western blotting. The cell viability was assayed by monotetrazolium （MTT） and the lactate dehydrogenase （LDH） and creatine phosphokinase （CPK） activity of cells during incubation and the changes in cells ultrastructure were examined. NF-κB activity in the primary neonatal rat myocardiocytes was measured with flow cytometry. Results Compared with viability in the A/R group （（35.4±6.9）%） the cell viability in the HS＋A/R group （（72.8±11.6）%） and the pCDNA HSP70 ＋ A/R group （（76.3±12.2）%） was improved significantly （P〈0.05）. The activity of LDH and CPK was significantly elevated in the A/R group. However, in the HS＋A/R group and pCDNA HSP70 ＋A/R group, significant decreases in activity were observed. The cell ultrastructure of the A/R group cells was abnormal, whereas nearly normal ultrastructure was observed in HS＋A/R group and pCDNA HSP70＋A/R group. HSP70 mRNA and protein were slightly expressed in the myocardiocytes of the A/R group. However, obvious overexpression was observed in the HS＋A/R group and in the pCDNA HSP70＋A/R group （P〈0.01）. And there was a significant difference between the HS＋A/R group and the pCDNA HSP70＋A/R group in the expression of HSP70 mRNA and protein （P〈0.01）. A high activity of NF-κB （5.76±0.64） was detected in the A/R group. But in the HS＋A/R group there was a statistically significant decrease in the activity of N F-KB compared with the A/R group （3.11±0.52 vs 5.76±0.64, P〈0.01 ）. The same statistically significant difference was also observed in the pCDNA HSP70 ＋ A/R group and A/R group （2.83±0.49 vs 5.76±0.64, P〈0.01 ）. Conclusions Overexpression of HSP70 alone by gene transfection leads to protection for cardiac myocyte against anoxia-reoxygeneration. These cardioprotective effects were related to the reduction in activation of NF-κB.

Use of cationic microbubbles targeted to P-selectin to improve ultrasound-mediated gene transfection of hVEGF_(165) to the ischemic myocardium

Gene therapies have been applied to the treatment of cardiovascular disease, but their use is limited by the need to deliver them to the right target. We have employed targeted contrast ultrasound-mediated gene transfection （TCUMGT） via ultrasound-targeted microbubble destruction （UTMD） to transfer therapeutic genes to specific anatomic and pathological targets. Phospholipid microbubbles （MBs） with pcDNA3.l-human vascular endothelial growth factor 165 （pcDNA3.I-hVEGFls5） plasmids targeted to P-selectin （MB＋P＋VEGFp） were created by conjugating monoclonal antibodies against P-selectin to the lipid shell. These microbubbles were divided into four groups： microbubble only （MB）, microbubble＋P-selectin （MB＋P）, microbubble＋pcDNA3.l-hVEGF185 plasmid （MB＋VEGFp）, and microbubbie＋ P-selectin＋pcDNA3.1-hVEGF185 piasmid （MB＋P＋VEGFp）. The reverse transcription polymerase chain reaction （RT-PCR） and enzyme-linked immunosorbent assay （ELISA） results showed that the VEGF gene was successfully transfected by TCUMGT and the efficiency is increased with P-selectin targeting moiety. UTMD-mediated delivery of VEGF increased myocardial vascular density and improved cardiac function, and MB＋P＋VEGFp delivery showed greater improvement than MB＋VEGFp. This study drew support from TCUGMT technology and took advantage of targeted ultrasound contrast agent to identify ischemic myocardium, release pcDNA3.1-hVEGF165 recombinant plasmid, and improve the myocardial microenvironment, so promoting the restoration of myocardial function.