Local Delivery of CTGF siRNA with Poly(sorbitol-co-PEI) Reduces Scar Contraction in Cutaneous Wound Healing

Healing process in scarring inevitably produces a considerable amount of non-organized dense collagen-rich matrix called scar thus impairing the native structure of skin. Connective tissue growth factor (CTGF) overexpression within healing tissues is known to play an imperative role in collagen production stimulated by transforming growth factor-beta in cutaneous wound healing. Undoubtedly, the knockdown of CTGF expression through siRNA-mediated gene silencing could simply impede the scarring process. However, the less stability and low transfection of siRNAs themselves urge a safe carrier to protect and transfect them into cells at a high rate avoiding toxicities. Here, we developed a degradable poly(sorbitol-co-PEI) (PSPEI), prepared by polymerization of sorbitol diacrylate with low molecular weight polyethylenimine, which has high transfection efficiency but low cytotoxicity, and utilized it in siCTGF delivery to silence the expression of CTGF in an animal model of cutaneous wound healing. Unlike contracted scar in normal healing, there was no or less contraction in the healed skin of mice treated with siCTGF using PSPEI. Histologically, the healed tissues also had distinct papillary structures and dense irregular connective tissues that were lacking in the control scar tissues. This study exemplifies a successful treatment of cutaneous wound healing using a polymer system coupled with RNA interference. Hence, the approach holds a great promise for developing new treatments with novel targets in regenerative medicines.

Effect of MT01/PEN complexes on the expression of osteoprotegerin and receptor activator of nuclear factor κB ligand in human osteoblast-like cell line MG63 / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aims to synthesize MTO1 (a kind of oligodeoxynucleotides) and N-isopropylacrylamide-modified polyethylenimines (PEN) complexes (MT01/PEN) as well as to investigate the effect of the complexes on the expression of osteoprotegerin (OPG) and the receptor activator of nuclear factor κB ligand (RANKL) in the human osteoblast-like cell line MG63.</p><p><b>METHODS</b>MG63 cells were transfected by MT01/PEN complexes formed with three different mass ratios (1:2, 1:4, 1:6) of MT01 to PEN. MT01 and MT01-s were used as positive control. Enzyme-linked immunosorbent assay and real-time polymerase chain reaction were performed to estimate the amount of OPG and RANKL released into the culture media and in MG63 at 24, 48, 72 h.</p><p><b>RESULTS</b>MG63 responded to the MT01/PEN complexes by significantly upregulating the OPG on the protein and mRNA levels (P < 0.05). The protein and mRNA levels of RANKL were lower in most of the groups with complexes, and the OPG/RANKL ratio were higher (P < 0.05). MG63 were affected by the MT01/PEN complexes with different mass ratios, particularly when the ratio was 1:6.</p><p><b>CONCLUSION</b>MT01 can enhance the promotion of ossification by establishing the delivery system with PEN.</p>

Novel Fabrication of MicroRNA Nanoparticle-Coated Coronary Stent for Prevention of Post-Angioplasty Restenosis

BACKGROUND AND OBJECTIVES: MicroRNA 145 is known to be responsible for cellular proliferation, and its enhanced expression reportedly inhibits the retardation of vascular smooth muscle cell growth specifically. In this study, we developed a microRNA 145 nanoparticle immobilized, hyaluronic acid (HA)-coated stent. MATERIALS AND METHODS: For the gene therapy, we used disulfide cross-linked low molecular polyethylenimine as the carrier. The microRNA 145 was labeled with YOYO-1 and the fluorescent microscopy images were obtained. The release of microRNA 145 from the stent was measured with an ultra violet spectrophotometer. The downstream targeting of the c-Myc protein and green fluorescent protein was determined by Western blotting. Finally, we deployed microRNA 145/ssPEI nanoparticles immobilized on HA-coated stents in the balloon-injured external iliac artery in a rabbit restenosis model. RESULTS: Cellular viability of the nanoparticle-immobilized surface tested using A10 vascular smooth muscle cells showed that MSN exhibited negligible cytotoxicity. In addition, microRNA 145 and downstream signaling proteins were identified by western blots with smooth muscle cell (SMC) lysates from the transfected A10 cell, as the molecular mechanism for decreased SMC proliferation that results in the inhibition of in-stent restenosis. MicroRNA 145 released from the stent suppressed the growth of the smooth muscle at the peri-stent implantation area, resulting in the prevention of restenosis at the post-implantation. We investigated the qualitative analyses of in-stent restenosis in the rabbit model using micro-computed tomography imaging and histological staining. CONCLUSION: MicroRNA 145-eluting stent mitigated in-stent restenosis efficiently with no side effects and can be considered a successful substitute to the current drug-eluting stent.

Hospitalización por episodios de cianosis en recién nacidos de edad gestacional igual o mayor a 34 semanas / Hospital Admissions due to cyanosis episodes in newborns with gestational age of 34 weeks or more

Objetivo: Caracterizar la hospitalización por episodios de cianosis en recién nacidos (RN) > 34 semanas. Pacientes y método: Estudio retrospectivo que incluyó la totalidad de los RN hospitalizados por episodios de cianosis entre enero de 2007 y diciembre de 2012. En ellos se aplicaron 2 protocolos de estudio que consideraban exámenes de primera y segunda línea; estos últimos ante la recurrencia de eventos. El protocolo de primera línea consideró exámenes bioquímicos generales, radiografía de tórax y ecocardiografía en casos seleccionados, en tanto que el protocolo de segunda línea incluyó electroencefalograma, electrocardiograma, resonancia magnética nuclear encefálica, screening metabólico ampliado, ácido pirúvico, ácido láctico y en caso de convulsiones, citoquímico y cultivo de líquido cefalorraquídeo y reacción en cadena de la polimerasa para herpes. Resultados: Noventa y ocho de un total de 3.454 (2,8%) RN hospitalizados ingresaron por episodio de cianosis. La edad gestacional (EG) fue 37,8 + 1,36 semanas; peso al nacimiento: 3145 + 477 g. Edad materna: 32 + 4,8 años. El 19,4% de las madres tenía antecedentes mórbidos: diabetes gestacional (8,1%), síndrome hipertensivo del embarazo (5,1%), colestasia intrahepática (3,1%) y retardo del crecimiento (3,1%). Género: 48,8% masculino, parto por cesárea: 68,4%. Edad al ingreso: 1,9 + 1,4 días; duración de la hospitalización: 4,2 + 4,2 días. En todos los pacientes se practicaron exámenes de primera línea y en el 39,8% exámenes de segunda línea. En el 21,4% de los RN se identificó una causa, siendo el síndrome convulsivo el más frecuente (33%). Los RN con diagnóstico asociado presentaron 3,8 + 2,7 episodios de cianosis versus 1,5 + 2,4 en el grupo sin diagnóstico (NS). El 15,4% se fueron de alta con monitor; no hubo reingresos. Conclusión: La incidencia de hospitalización neonatal por episodios de cianosis fue de 6 por 1.000 RN vivos. Solo en cerca de un 20% de ellos es posible identificar una causa, siendo la más frecuente el síndrome convulsivo.

Objectives: A retrospective study was performed between January 2007 and December 2012 to assess the admission rates of newborns due to episodes of cyanosis Patients and method: Retrospective study that included all the newborns hospitalized with episodes of cyanosis between January 2007 and December 2012. In them were employed two study protocols that considered first and second line tests, the latter in view of recurrence of events. The first line protocol considered general biochemical tests, chest x-ray and echocardiography in selected cases, while the second line protocol included electroencephalogram, electrocardiogram, nuclear magnetic resonance of the brain, expanded metabolic screening, pyruvic acid, lactic acid, and in case of seizures, cytochemical, and culture of cerebrospinal fluid (CSF) and PCR (polymerase chain reaction) for herpes. Results: A total of 98 (2.8%) out of 3,454 newborns were admitted due to episodes of cyanosis. Gestational age: 37.8 + 1.4 weeks, birth weight: 3,145 + 477 g. Maternal age: 32 + 4.8 years. Disease was present in 19.4% of mothers; gestational diabetes (8.1%), pregnancy induced hypertension (5.1%), intrahepatic cholestasis (3.1%), and intrauterine growth retardation (3.1%). Gender: 48.8% male, 51.2% female (NS). Birth: caesarean section, 68.4%, and vaginal delivery, 31.6%. Age on admission 1.9 + 1.4 days. Hospital stay: 4.2 + 4.2 days. First line tests were performed in 100% of patients with 39.8% fulfilling the criteria for second line study. A condition was detected in 21.4%, with convulsive syndrome was the most frequent (33%). Newborns with an identified condition had 3.8 + 2.7episodes versus 1.5 + 2,4 in those without diagnosis (NS). A home oxygen monitor was given to 15.4%. There were no re-admissions. Conclusions: Most newborns admitted due to cyanosis are discharged with a condition of unknown origin. In this study, convulsive syndrome was the most frequent cause.

Optimization of triple plasmids transfection into HEK293 cells mediated by polyethylenimine / 生物医学工程学杂志

In the present study, packaging system composed of pAAV-CMV-GFP, pAAV-RC and pHelper were transfected into human embryonic kidney 293 cells (HEK293 cells) mediated by polyethyleneimine (PEI) to explore an optimal transfection condition. Different total plasmid DNA dosages (1, 2, 3, 4, 5, 6 μg) and different PEI/Plasmid ratios (1:1, 3:1, 5:1, 7:1) were tested with detection of green fluorescence protein (GFP) with ImagePro Plus6. 0 Software. Then transfection efficiency of the optimized transfection system was further observed for different time periods(12, 24, 36, 48, 60, 72 h). The results showed that total plasmid dosage of 4 μg/well with PEI/plasmid ratio of 3 : 1-5 : 1 was an efficient transfection condition. Transfection efficiency-time curve was an S-shaped curve. Transfection efficiency reached a plateau at 60 h after transfection. The optimized conditions for PEI-mediated transfection at the optimal time result in enhanced transfection efficiency of triple plasmid into HEK293 cells.

Preparation and property evaluation of graphene oxide based silver nanoparticles composite materials / 生物医学工程学杂志

We prepared silver nanoparticles/polyethyleneimine-reduction graphene oxide (AgNP/rGO-PEI) composite materials, and evaluated their quality performance in our center. Firstly, we prepared AgNP/rGO-PEI, and then analysed its stability, antibacterial activity, and cellular toxicity by comparing the AgNP/rGO-PEI with the silver nanoparticles (PVP/AgNP) modified by polyvinylpyrrolidone. We found in the study that silver nanoparticles (AgNP) distributed relatively uniformly in AgNP/rGO-PEI surface, silver nanoparticles mass fraction was 4.5%, and particle size was 6-13 nm. In dark or in low illumination light intensity of 3 000 lx meter environment (lux) for 10 days, PVP/AgNP aggregation was more obvious, but the AgNP/rGO-PEI had good dispersibility and its aggregation was not obvious; AgNP/rGO-PEI had a more excellent antibacterial activity, biological compatibility and relatively low biological toxicity. It was concluded that AgNP/rGO-PEI composite materials had reliable quality and good performance, and would have broad application prospects in the future.

Angiogenic activity of alginate-graft-PEI/pVEGF complexes in vivo / 生物工程学报

To study the angiogenic activity of amphoteric brush-type copolymer complex of alginate-graft-PEI/pVEGF (Alg-g-PEI/pVEGF) in vivo, we evaluated the toxicity of Alg-g-PEI/pVEGF complexes to rMSCs and zebra fish first. Then, we used gel retardation assay to investigate the protection of complex to pDNA against DNase I, serum and heparin. For in vivo study, we evaluated the angiogenic activity of Alg-g-PEI/pVEGF complexes by using CAM and zebra fish as animal models, PEI 25K/pVEGF and saline as positive and negative controls. Our results show that Alg-g-PEI protected pVEGF from enzymolysis and displacement of heparin in some degree, and its complexes with pVEGF were less toxic to rMSCs and zebra fish. Alg-g-PEI/pVEGF complexes induced significant angiogenesis, which was dosage-dependent. In CAM, when the dosage of pVEGF was 2.4 microg/CAM, Alg-g-PEI group achieved the maximum of angiogenesis, and the area ratio of vessel to the total surface was 44.04%, which is higher than PEI 25K group (35.90%) and saline group (24.03%) (**P < 0.01). In zebra fish, the angiogenesis increased with the increase of N/P ratios of Alg-g-PEI/pVEGF complexes in our studied range; when N/P ratio was 110, the optimal angiogenesis was obtained with vessel length of 1.11 mm and area of 1.70 x 10(3) pixels, which is higher than saline group (0.69 mm and 0.94 x 10(3) pixels) (**P < 0.01) and PEI 25k group (0.82 mm and 1.11 x 10(3) pixels) (**P < 0.01). Our results demonstratethat Alg-g-PEI/pVEGF significantly induces angiogenesis in CAM and zebra fish, and has a great potential in therapeutic angiogenesis.

Synthesis and characterization of PEG-b-(PG-g-PEI) for gene delivery / 南方医科大学学报

<p><b>OBJECTIVE</b>To synthesize a biodegradable non-viral gene carrier with a high transfection efficiency and a low cytotoxicity.</p><p><b>METHODS</b>Poly(ethylene glycol)-block-(poly(L-glutamic acid)-graft-polyethylenimine) was prepared via ammonolysis of poly(ethylene glycol)-block-poly (γ-benzyl L-glutamate) with the low-molecular-mass polyethylenimine (600 Da). The synthesized copolymer was characterized by 1H nuclear magnetic resonance spectroscopy and gel permeation chromatography. The polyplex micelle from PEG-b-(PG-g-PEI) and plasmid DNA (pDNA) was studied using dynamic light scattering, zeta-potential measurements, and gel retardation assay. The in vitro cytotoxicity and transfection efficiency of PEG-b-(PG-g-PEI) were tested by MTT assay and luciferase assay in HEK 293T cells using PEI (25 kDa) as the control.</p><p><b>RESULTS</b>PEG-b-(PG-g-PEI) could efficiently condense DNA into nanosized particles with positive surface charges when the N/P ratio of polymer and DNA was above 5:1. The zeta potential of the polyplexes was about 25 mV, and the particle size was 120 nm at a N/P ratio of 10. The cell toxicity and gene transfection evaluations showed a lower cytotoxicity and a higher gene transfection efficiency of the copolymer than PEI 25000 in HEK 293T cells.</p><p><b>CONCLUSIONS</b>The polymer can be used as a potential non-viral gene carrier for gene therapy.</p>

Biocompatibility of polyethylene imine (PEI)-coated magnetic Fe₃O₄ nanoparticles in SHI-1 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the feasibility of magnetic resonance cell imaging technology by using polyethylene imine (PEI)-coated magnetic nanoparticles of Fe₄O₄ (PEI-Fe₄O₄-MNPs) to track cell biology behavior.</p><p><b>METHODS</b>Endocytic PEI-Fe₄O₄-MNPs in SHI-1 cells were observed by transmission electron microscopy (TEM) . Iron contents of nano-labeled cells were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and Prussian blue staining. The proliferation ability of labeled cells was detected by cell counting kit-8 (CCK-8) assay; the differentiation and colony-forming abilities were also observed. SHI-1 cells without endocytosing PEI-Fe₄O₄-MNPs were used as control.</p><p><b>RESULTS</b>Our data showed that PEI-Fe₄O₄-MNPs could label SHI-1 cells. The labeling efficiency depended on the nanoparticles' concentration and the duration of cells treating. Inhibition rates of SHI-1cells labeled by 60-100 μg Fe/ml PEI-Fe₄O₄-MNPs were much higher than of 5-50 μg Fe/ml ones following treating by 5-100 μg Fe/ml PEI-Fe₄O₄-MNPs for 48 hrs. The expressions of CD11b and CD14 were (78.4±18.5)% and (18.7±2.9)% in control vs (83.3±14.2)% and (20.4±2.1)% in cells fractions treated by 30 μg Fe/ml PEI-Fe₄O₄-MNPs. Clony-forming rates of SHI-1 cells labeled by 0, 20 , 50 μg Fe/ml PEI-Fe₄O₄-MNPs were (25.20±7.22)%, (25.93±13.15)%, (23.37±9.33)%, respectively. Differentiation and colony-forming potentials of labeled cells were similar with control in the certain range of PEI-Fe₄O₄-MNPs concentration.</p><p><b>CONCLUSION</b>SHI-1 cells were efficiently labeled by PEI-Fe₄O₄-MNPs with well biocompatibilities in proper range of concentration, the latter could be coupled with magnetic resonance imaging (MRI) to track cells in vivo.</p>

Synthesis of a supermolecular nanoparticle γ-hy-PC/Ada-Dox and its antitumor activity / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To synthesize a (2-Hydroxypropyl)-γ-cyclodextrin-polyethylenimine/adamantane-conjugated doxorubicin (γ-hy-PC/Ada-Dox) based supramolecular nanoparticle with host-guest interaction and to identify its physicochemical characterizations and antitumor effect.</p><p><b>METHODS</b>A novel non-viral gene delivery vector γ-hy-PC/Ada-Dox was synthesized based on host-guest interaction. 1H-NMR, NOESY, UV-Vis, XRD and TGA were used to confirm the structure of the vector. The DNA condensing ability of complexes was investigated by particle size, zeta potential and gel retardation assay. Cytotoxicity of complexes was determined by MTT assay in BEL-7402 and SMMC-7721 cells. Cell wound healing assay was performed in HEK293 and BEL-7404 cells. The transfection efficiency was investigated in HEK293 cells. H/E staining and cell uptake assay was performed in BEL-7402 cells.</p><p><b>RESULTS</b>The structure of γ-hy-PC/Ada-Dox was characterized by 1H-NMR, NOESY, UV-Vis, XRD, TGA. The drug loading was 0.5% and 5.5%. Gel retardation assay showed that γ-hy-PC was able to completely condense DNA at N/P ratio of 2; 0.5% and 5.5% γ-hy-PC/Ada-Dox was able to completely condense DNA at N/P ratio of 3 and 4,respectively. The cytotoxicity of polymers was lower than that of PEI25KDa. The transfection efficiency of γ-hy-PC was higher than that of γ-hy-PC/Ada-Dox at N/P ratio of 30 in HEK293 cells; and the transfection efficiency was decreasing when Ada-Dox loading was increasing. Cell uptake assay showed that γ-hy-PC/Ada-Dox was able to carry drug and FAM-siRNA into cells.</p><p><b>CONCLUSION</b>The novel vector γ-hy-PC/Ada-Dox has been developed successfully, which has certain transfection efficiency and antitumor activity.</p>

Anticancer effect of triptolide-polyethylenimine-cyclodextrin in vitro / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop a drug delivery system triptolide-polyethylenimine-cyclodextrin and to evaluate its anticancer activity in vitro.</p><p><b>METHODS</b>Triptolide was conjugated to polyethylenimine-cyclodextrin by N, N'-carbonyldiimidazole to form triptolide-polyethylenimine-cyclodextrin. (1)H-NMR, FT-IR and XRD were used to confirm its structure. The anticancer effect of the polymer was assessed by MTT assay, erasion trace test and hematoxylin-eosin staining. The potential to condense siRNA and to delivery siRNA into cytoplasm was demonstrated by gel retardation assay, zeta-potential determination and fluorescence staining.</p><p><b>RESULTS</b>Triptolide was successfully conjugated to polyethylenimine-cyclodextrin and the conjugation rate of triptolide was 10% (w/w). siRNA was effectively condensed by the polymer at the N/P ratio of 5, and its particle size was 300 ±15 nm and zeta potential was 8 ±2.5 mV. MTT assay, erasion trace test and hematoxylin-eosin staining revealed that triptolide-polyethylenimine-cyclodextrin had anticancer effect and low cytotoxicity to normal cells. The polymer was able to deliver siRNA to the cytoplasm effectively as demonstrated by fluorescence staining.</p><p><b>CONCLUSION</b>Triptolide-polyethylenimine-cyclodextrin is able to inhibit the growth and migration of cancer cells in vitro and to carry siRNA into cells effectively. It is potential to be used as a novel prodrug for co-delivery of gene and drug in cancer treatment.</p>

Characteristics of cationic polymers PEI-CyD, PEI-PHPA, PEE-PHPA and PEI25kD in vitro and in vivo / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To study the characteristics of cationic polymers polyethylenimine-β-cyclodextrin (PEI-CyD), polyethylenimine-poly-(3-hydroxypropyl)-aspartamide (PEI-PHPA), N,N-Dimethyldipropylenetriamine-Bis(3-aminopropyl)amine-aspartamide (PEE-PHPA) in vitro and in vivo.</p><p><b>METHODS</b>PEI-PHPA, PEI-CyD and PEE-PHPA were synthesized and the chemistry structure of PEI-PHPA, PEI-CyD and PEE-PHPA was confirmed by (1)H-NMR. The particle size and zeta potential of these polymers were measured, and capacity of plasmid DNA condensation was tested. The inhibition of COS-7, A549, HEK293 and C6 cells was measured by MTT assay. The transfection efficiency was determined in HEK293 cell lines. The toxicity, tissue distribution and transfection efficiency of cationic polymers were tested in vivo.</p><p><b>RESULTS</b>When the N/P of polymers/DNA at 30, the particle sizes were close 250 nm and the zeta-potential were near 35 mv. They were able to condense DNA at N/P ratio < 5. The MTT assay showed that the IC(50) of PEE-PHPA was 21.5, 20.2, 7.30 and 37.1 μg/ml, and that of PEI25kD was 15.8, 18.3, 11.4 and 36.7 μg/ml in C6, COS-7, A549 and HEK293cell lines, respectively. The cell viability of PEI-CyD and PEI-PHPA in above cell lines was over 60%. They had high transfection efficiency in HEK293 cell lines. The LD(50) of PEI25Kd, PEI-CyD, PEI-PHPA and PEE-PHPA in vivo was 19.50, 100.4, 521.2 and 630.0, respectively by intraperitoneal (ip) injection. The contractions of these polymers were higher in kidney than in other organs and tissues.PEE-PHPA had slight effect on kidney and liver function.</p><p><b>CONCLUSION</b>PEE and PEI25kD have higher transfection efficiency and higher toxicity; while PC and PHPA-PEI have lower toxicity and higher transfection efficiency to be used as non-viral gene vector.</p>

Modified montmorillonite as multifunction gene and drug delivery system / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop polyethylenimine-Doxorubicin-montmorillonite (PEI-Dox-MTT) as a novel multifunction delivery system.</p><p><b>METHODS</b>Dox was intercalated into montmorillonite, PEI covered to the surface of Dox/MMT to make the nano-particle. XRD, FT-IR and TGA were used to confirm chemical property of the nano-particle. SEM was used to observe the morphology. The capability of drug release was investigated by PBS buffer solution (pH 7.4). The DNA binding ability of nano-particle was detected by gel electrophoresis retardation assay. The cell viability in COS-7 and SKOV3 cell lines was tested using MTT assay. The gastric mucosa protection was evaluated in vitro.</p><p><b>RESULTS</b>XRD image showed that Dox was intercalated into montmorillonite, inter space of which increased to 31.3Å; the FT-IR spectra showed the vibration bands of PEI at 1 560 cm(-1) and 2 850 cm(-1), the vibration band of Dox at 1 350 cm(-1). Size analysis and SEM revealed that the size of nano-particle was 600 nm, and the zeta-potential was 30 mV. Drug release experiment explored that the nano-particle stably released drug in range of 6 X10(-4) ≊ 8 X10(-4) mg/ml within 72 h. MTT assay showed that the cell viability was over 80% in experiment condition in COS-7 and SKOV3 cell lines. 0.3 mg PEI-MMT nano-particle was able to protect gastric mucosa from alcohol.</p><p><b>CONCLUSION</b>Multifunction system of PEI/Dox/MMT has been prepared successfully.</p>

Mycobacterium under AFM tip: advantages of polyelectrolyte modified substrate

Immobilization of bacterial cells onto surfaces is critical for imaging with an atomic force microscope. In this paper, polyethylenimine [PEI] coated silicon plates are shown to be suitable for immobilizing and imaging Mycobacterium tuberculosis

Silencing effect of cell-specific RNA interference plasmid pPSMAe/p-shNS-ploy(A) loaded by transgenic vector Tf-PEG-PEI targeting nucleostemin on prostate cancer cells in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the transgenic efficiency of non-viral vector Tf-PEG-PEI and the cell specific silencing effect of plasmid pPSMAe/p-shNS-ploy(A) on prostate cancer cells.</p><p><b>METHODS</b>Polyethyleneimine (PEI) was modified by using polyethylene glycol and transferrin to synthesize the non-viral vector Tf-PEG-PEI. NS-specific plasmids pPSMAe/p-shNS-ploy(A) and Tf-PEG-PEI were used to transfect prostate cancer LNCap and PC-3 cells. The changes of cell morphology, proliferation ability and cell cycle were studied after down-regulating the NS gene level.</p><p><b>RESULTS</b>Tf-PEG-PEI was successfully modified. After transfection, the PSMA-expressing LNCaP cells became larger and showed more pseudopodia, having a tendency to differentiate. Their cell proliferation ability was reduced, and the detection of cell cycle showed a decrease of S phase and an increase of G(1) phase after knocking down NS gene. These targets were not changed in non-PSMA-expresing PC-3 cells.</p><p><b>CONCLUSIONS</b>The non-viral vector Tf-PEG-PEI has a high ability to transfer targeted gene into target cells. The cellular specificity of short-hairpin RNA transcription driven by PSMAe/p is confirmed by silencing NS gene. The use of cell specific promoter may be an effective strategy of gene therapy for prostate cancer.</p>

Small interfering RNA delivery mediated by mPEG-PCL-g-PEI polymer nanoparticles / 药学学报

The aim of this paper is to report the synthesis of the mPEG-PCL-g-PEI copolymers as small interfering RNA (siRNA) delivery vector, and exploration of the siRNA delivery potential of mPEG-PCL-g-PEI in vitro. The diblock copolymers mPEG-PCL-OH was prepared through the ring-opening polymerization. Then, the hydroxyl terminal (-OH) of mPEG-PCL-OH was chemically converted into the carboxy (-COOH) and N-hydroxysuccinimide (NHS) in turn to prepare mPEG-PCL-NHS. The branched PEI was reacted with mPEG-PCL-NHS to synthesize the ternary copolymers mPEG-PCL-g-PEI. The structure of mPEG-PCL-g-PEI copolymers was characterized with Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The mPEG-PCL-g-PEI/siRNA nanoparticles were prepared by complex coacervation, and the nanoparticles size and zeta potential were determined, separately. The cytotoxicities of mPEG-PCL-g-PEI/siRNA nanoparticles and PEI/siRNA nanoparticles were compared through cells MTT assays in vitro. The inhibition efficiencies of firefly luciferase gene expression by mPEG-PCL-g-PEI/ siRNA nanoparticle at various N/P ratios were investigated through cell transfection in vitro. The experimental results suggested that the ternary (mPEG5k-PCL(1.2k))1.4-g-PEI(10k) copolymers were successfully synthesized. (mPEG(5k)-PCL(1.2k))1.4-g-PEI(10k) could condense siRNA into nanoparticles (50-200 nm) with positive zeta potential. MTT assay results showed that the cytotoxicity of (mPEG(5k)-PCL(1.2k))1.4-g-PEI(10k)/siRNA nanoparticles was significantly lower than that of PEI(10k)/siRNA nanoparticles (P < 0.05). The expression of firefly luciferase gene could be significantly down-regulated at a range of N/P ratio from 50 to 150 (P < 0.01), and maximally inhibited at the N/P ratio of 125. The mPEG-PCL-g-PEI polymers could delivery siRNA into cells to inhibit the expression of target gene with very low cytotoxicity, which suggested that mPEG-PCL-g-PEI could serve as a new type of siRNA delivery vector.

Enhancing microRNA transfection to inhibit survivin gene expression and induce apoptosis: could it be mediated by a novel combination of sonoporation and polyethylenimine? / 中华医学杂志(英文版)

Apoptosis is a physiologically essential mechanism of cell and plays an important role in reducing the development and progression of tumors. The appealing strategy for cancer therapy is to target the lesions that induce apoptosis in cancer cells. Survivin, the smallest member of the mammalian inhibitors of the apoptosis protein family, is upregulated in various malignancies to protect cells from apoptosis. Survivin knockdown could induce cancer cell apoptosis and inhibit tumor-angiogenesis. Survivin expression would be silenced by microRNA (miRNA)-mediated RNA interference. However, noninvasive and tissue-specific gene delivery techniques remain absent recently and the utilizations of miRNA expression vectors have been limited by inefficient delivery technique, especially in vivo. On the other hand, safe and promising technologies of gene transfection would be valuable in clinical gene therapy. Successful treatment of gene transfer method would lead to a new and readily available approach in the anticancer research. Sonoporation is an alternative technique of gene delivery that uses ultrasound targeted microbubble destruction to create pores in the cell membrane. Based on our previous studies, in this article, we postulated that the transfection of miRNA could be mediated by the combination of sonoporation and polyethylenimine (PEI) which was one of the most effective poly-cationic gene vectors and enhance the endocytosis of plasmids DNA and hypothesized that the gene silencing and apoptosis induction with miRNA targeting human Survivin would be improved by this novel technique. In our opinion, this novel combination of sonoporation and PEI could enhance targeted gene delivery effectively and might be a feasible, novel candidate for gene therapy.

Hepatocyte Growth Factor and Kidney Disease / 대한신장학회지

Hepatocyte growth factor (HGF), also known as scatter factor, was identified during the experimental attempts to explore a phantom factor acting as a trigger for liver regeneration after partial hepatecotmy. HGF is synthesized and secreted as a single-chain inert precursor by cells of mesodermal origin, and extracellularly processed to the two-chain functional heterodimer by proteolytic cleavage at a specific site. The binding of HGF to the c-MET, the HGF receptor, induces activation of tyrosine kinase and autophosphorylation of tyrosine residues. c-MET activation propagates an intricate system of signaling pathways that controls a range of cellular processes as diverse as cell proliferation, differentiation, transformation and apoptosis. In the aspect of kidney, the HGF/c-MET signaling pathway plays important roles in renal development and in the maintenance of normal adult kidney structure and function. In various injury and disease models, HGF has been reported to promote cell survival, tissue regeneration, and fibrosis suppression. Neutralization of HGF by the antibody may accelerate renal failure or fibrosis while HGF administration may lead to remarkable amelioration. Thus, HGF is not only the endogenous safeguard protecting normal tissues against the fibrotic process after injury, but also a therapeutic option to prevent organ failure. If insufficient production of HGF is causative for renal fibrosis, administration of recombinant human HGF protein or HGF gene therapy may improve renal fibrosis and dysfunction. HGF gene therapy requires appropriate delivery systems, and biodegradable polyester amine based on glycerol dimethacrylate and polyethylenimine is being tested for the HGF gene carrier in experimental models.

Application of orthogonal design in optimization of the transfection efficiency of polyethylenimine mediated gene transfer to hepatoma carcinoma cells / 生物医学工程学杂志

This study was aimed to develop non-toxic, high transfection efficiency polyethyleneimine(PEI) cationic nanoparticles. The exosyndrome of PEI cationic nanoparticles was measured by zeta sizer, ultraviolet and visible spectroscopy. The condensation ability and the resistance to DNaseI of pEGFP-N1/PEI and pEGFP-N1/PEI modified polyethylene glycol(PEG) were evaluated by agarose gel electrophoresis. The cell toxicity of polyethyleneimine cationic nanoparticles was measured by using MTT test. The orthogonal design was used to optimize the transfection efficiency with the N/P ratio, the grafting ratio and the gene dosage as the factors. The experimental results showed that pEGFP-N1/PEI nanoparticles have lower cell toxicity, better composite ability and better resistance to DNAseI. The highest transfection efficiency of PEI cationic nanoparticles was 91% by using the PEI nanoparticles with the N/P ratio 40:1 and gene dosages 6 microg/well. PEI cationic nanoparticle modified by PEG effectively transferred DNA to hepatoma carcinoma cells and it is a non-toxic, with high transfection efficiency, and a promising non-viral carrier for gene delivery. The transfection efficiency will be improved by optimizing the experiment condition.

Progress of nanometer vector polyethylenimine applied in gene therapy / 生物医学工程学杂志

Polyethylenimine (PEI) is a kind of nanometer nonviral vector frequently applied in gene transfection. It is simple and easy to prepare and to modify and relatively safe compared to viral vectors. In recent years, PEI has been utilized in many research areas for gene delivery to stem cells in vitro or targeted gene delivery to cells in the brain. This review reveals that the cytotoxicity and low transfection efficiency of PEI requires to be improved. However brain-targeted modification indicates the promising prospect of PEI for gene therapy in cerebrovascular diseases.