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ABSTRACT: Pigment epithelium-derived factor (PEDF) recombinant protein has been investigated in many kinds of solid tumors due to its potent antiangiogenic activity. However, the complexity of protein purification, instability of recombinant protein and requirement of repeated injections are obstacles for the recombinant PEDF therapy for solid tumors. We successfully synthesized polyethyleneglycol-polyetherimide (PEG-PEI) and cRGD-PEG-PEI which was coupled with a cyclic RGD peptide, a special ligand for integrin αvβ3 receptor, as the vehicle for PEDF gene therapy in this study. In vitro, the competitive binding assay showed that cRGD contributed to the enhanced gene transfection efficiency of PEG-PEI in human umbilical vein endothelial cells (HUVECs). PEDF gene delivered by cRGD-PEG-PEI apparently suppressed growth of tumor with a 67.4% reduction and decreased microvessel density in nude mice bearing SW620 human colorectal xenografts. Accordingly, SW620 tumors from cRGD-PEG-PEI/PEDF-pcDNA3.1 (+)-treated mice expressed more PEDF than that of the control groups. Our study demonstrated that cRGD-PEG-PEI transported the PEDF gene into endothelia cells more efficiently than PEG-PEI, resulting in more effective inhibitory effects on tumor growth by anti-angiogenesis. Therefore, for the first time, we have explored an effective non-viral vehicle for PEDF gene therapy by targeting endothelial cells.
International journal of pharmaceutics 09/2012; 438(1-2):1-10. · 2.96 Impact Factor
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ABSTRACT: Lead ion (Pb²⁺) accumulation in nature can affect the environment and human health severely. Thus, rapid and sensitive detection is of great importance. One-step detection of Pb²⁺ at attomole levels was realized by using dynamic light scattering (DLS) technique coupled with unmodified gold nanoparticles (AuNPs). Pb²⁺-dependent DNAzyme was double-stranded and could not adsorb on the surface of AuNPs, while the substrate strand could be cleaved into ssDNA fragments on addition of Pb²⁺. The ssDNA fragments could adsorb on the surface of AuNPs and prevent them from aggregating in the presence of NaCl. Therefore, the disperse state of AuNPs changed on addition of Pb²⁺ in the presence of DNAzyme and NaCl, which was estimated with an average hydrodynamic diameter by using DLS. Under optimum conditions, the average diameter of the solution decreased linearly with the concentration of Pb²⁺ over the range from 10 to 300 pM, with a detection limit of 6.2 pM. Moreover, satisfactory results were obtained when the proposed method was applied in the detection of Pb²⁺ in water samples.
Analytical Biochemistry 12/2011; 421(2):582-6. · 3.00 Impact Factor
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ABSTRACT: An ultrasensitive and simple dynamic-light-scattering (DLS) assay for the sequence-specific recognition of double-stranded DNA (dsDNA) was developed based on detection of the average diameter change of Au nanoparticle (AuNP) probes modified with oligonucleotides 5'-TTTCTCTTCCTT- CTCTTC-(T)(12)-SH-3' (Oligo 1) and 5'-TTCTTTCTTTTCTTTTTC-(T)(12)- SH-3' (Oligo 2). The target dsDNA was composed of two complementary oligonucleotides: 5'-AAAGAGAAGGAAGAGAAGAAGAAAGAAAAGAAAAAG-3' (Oligo 3) and 3'-TTTCTCTTCCTTCTCTTCTTCTTTCTTTTCTTTTTC-5' (Oligo 4). Hybridization of the two AuNPs-Oligo probes with the target dsDNA induced aggregation of the target dsDNA by forming triplex DNA, which accordingly increased the average diameter. This diameter change could then be detected by DLS. The average diameter was proportional to the target dsDNA concentration over the range from 593 fM to 40 pM, with a detection limit of 593 fM. Moreover, the assay had good sequence specificity for the target dsDNA.
Chemistry 09/2011; 17(40):11230-6. · 5.93 Impact Factor
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ABSTRACT: Mesenchymal stem cell transplantation is a promising method in regenerative medicine. Gene-modified mesenchymal stem cells possess superior characteristics of specific tissue differentiation, resistance to apoptosis, and directional migration. Viral vectors have the disadvantages of potential immunogenicity, carcinogenicity, and complicated synthetic procedures. Polyethylene glycol-grafted polyethylenimine (PEG-PEI) holds promise in gene delivery because of easy preparation and potentially targeting modification.
A PEG8k-PEI25k graft copolymer was synthesized. Agarose gel retardation assay and dynamic light scattering were used to determine the properties of the nanoparticles. MTT reduction, wound and healing, and differentiation assays were used to test the cytobiological characteristics of rat mesenchymal stem cells, fluorescence microscopy and flow cytometry were used to determine transfection efficiency, and atomic force microscopy was used to evaluate the interaction between PEG-PEI/plasmid nanoparticles and mesenchymal stem cells.
After incubation with the copolymer, the bionomics of mesenchymal stem cells showed no significant change. The mesenchymal stem cells still maintained high viability, resettled the wound area, and differentiated into adipocytes and osteoblasts. The PEG-PEI completely packed plasmid and condensed plasmid into stable nanoparticles of 100-150 nm diameter. After optimizing the N/P ratio, the PEG-PEI/plasmid microcapsules delivered plasmid into mesenchymal stem cells and obtained an optimum transfection efficiency of 15%-21%, which was higher than for cationic liposomes.
These data indicate that PEG-PEI is a valid gene delivery agent and has better transfection efficiency than cationic liposomes in mesenchymal stem cells.
International Journal of Nanomedicine 01/2011; 6:843-53. · 3.13 Impact Factor
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Bing Liang,
Ming-Liang He,
Chu-yan Chan,
Yang-chao Chen,
Xiang-Ping Li,
Yi Li,
Dexian Zheng,
Marie C Lin,
Hsiang-Fu Kung, Xin-Tao Shuai,
Ying Peng
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ABSTRACT: Combined treatment using nonviral agent-mediated enzyme/prodrug therapy and immunotherapy had been proposed as a powerful alternative method of cancer therapy. The present study was aimed to evaluate the cytotoxicity in vitro and the therapeutic efficacy in vivo when the cytosine deaminase/5-fluorocytosine (CD/5-FC) and TNF-related apoptosis-inducing ligand (TRAIL) genes were jointly used against rat C6 glioma cells. The potency of the FA-PEG-PEI used as a nonviral vector was tested in the FR-expressed C6 glioma cells and Wistar rats. The C6 glioma cells and animal model were treated by the combined application of FA-PEG-PEI/pCD/5-FC and FA-PEG-PEI/pTRAIL. The antitumor effect was evaluated by survival assays and tumor volume. This study revealed a significant increase of cytotoxicity in vitro following the combined application of FA-PEG-PEI/pCD/5-FC and FA-PEG-PEI/pTRAIL treatments in C6 glioma cells. Animal studies showed a significant growth inhibition of the C6 glioma xenografts using the combined treatment. These results demonstrated that the combined treatment generated additive cytotoxic effect in C6 glioma cells in both in vitro and in vivo conditions, and indicated that such treatment method using both enzyme/prodrug therapy and TRAIL immunotherapy might be a promising therapeutic strategy in treating glioma.
Biomaterials 06/2009; 30(23-24):4014-20. · 7.40 Impact Factor
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ABSTRACT: To prepare gemcitabine-loaded nanovesicles and to observe its morphology, structure, particle size, and drug-release performance in vitro.
Diemulsion technique was used to prepare nanovesicles as carrier from amphiphilic block copolymer of poly (ethylene glycol)-block-poly (D, L-lactide), and gemcitabine was used as the model drug. The morphology of vesicles was determined by scanning electron microscope (SEM) and transmission electron microscope (TEM), and its drug loading (DL), encapsulation ratio (ER), and drug-release curve in vitro were detected by UV-Vis-NIR Spectrophotometer.
The Gemcitabine-loaded nanovesicles is a kind of hollow nanosphere with the mean size of 200.6 nm, DL of 4.14% and ER of 20.54%. The nanovesicles showed its excellent controlled-release characteristic in the experiment of drug release in vitro.
The nanovesicles prepared from PEG-PDLLA can be served as one of carriers for Gemcitabine with good performance of drug controlled-release. It will provide a reliable experimental base for the further researches in vivo.
Zhonghua yi xue za zhi 08/2008; 88(28):2005-7.
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ABSTRACT: A great challenge for gene therapy is to develop a high efficient gene delivery system with low toxicity. Nonviral vectors are still attractive although the current agents displayed some disadvantages (i.e., low transfection efficiency, high toxicity). To overcome the high toxicity of poly(ethylene imine) (PEI) and low transfection efficiency of PEGylated PEI (PEG-PEI), we linked a cell specific target molecule folate (FA) on poly(ethylene glycol) (PEG) and then grafted the FA-PEG onto hyperbranched PEI 25kDa. The FA-PEG- grafted-hyperbranched-PEI (FA-PEG-PEI) effectively condensed plasmid DNA (pDNA) into nanoparticles with positive surface charge under a suitable N/P ratio. Tested in deferent cell lines (i.e., HEK 293T, glioma C6 and hepatoma HepG2 cells), no significant cytotoxicity of FA-PEG-PEI was added to PEG-PEI. More importantly, significant transfection efficiency was exhibited in FA-targeted cells. Reporter assay showed that FA-PEG-PEI/pDNA complexes had significantly higher transgene activity than that of PEI/pDNA in folate-receptor (FR) positive (HEK 293T and C6) cells but not FR-negative (HepG2) cells. These results indicated that FA-PEG-PEI might be a promising candidate for gene delivery with the characteristics of good biocompatibility, potential biodegradability, and relatively high gene transfection efficiency.
Biochemical and Biophysical Research Communications 04/2008; 367(4):874-80. · 2.48 Impact Factor
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ABSTRACT: FG020326, a novel imidazole derivative, is a potent multidrug-resistance (MDR) modulator in vitro and in vivo. However, FG020326 is insoluble. PEDLLA-FG020326 is a FG020326-loaded nanoparticle formed with diblock copolymers of poly (ethylene glycol)-block-poly (D,L-lactic acid) (PEG:PDLLA, PEDLLA) that can solubilize FG020326. This work was intended to evaluate the pharmacodynamics of PEDLLA-FG020326 on reversing MDR in vitro and in vivo.
Cytotoxicity was determined by tetrazolium assay. The intracellular accumulation and efflux of doxorubicin (Dox) were detected by fluorescence spectrophotometry. The function of P-glycoprotein was examined by Rhodamine 123 (Rh123) accumulation detected by flow cytometry. The KBv200 cell xenograft model was established to investigate the effect of PEDLLA-FG020326 on reversing MDR in vivo.
PEDLLA-FG020326 and FG020326 exhibited 56.4- and 35.9-fold activity in reversing KBv200 cells to vincristine (VCR) resistance, respectively and 14.98- and 7.64-fold to Dox resistance, respectively. PEDLLA-FG020326 was much stronger than FG020326, resulting in the increase of Dox and Rh123 accumulation and the decrease of intracellular Dox extrusion in KBv200 cells. Importantly, PEDLLA-FG020326 exhibited more powerful activity than FG020326 in enhancing the effect of VCR against KBv200 cell xenografts in nude mice, but did not appear more toxic.
The pharmacodynamics of FG020326 was improved by incorporating it into a micellar nanoparticle formed with PEG-block-PDLLA copolymers.
Acta Pharmacologica Sinica 07/2007; 28(6):913-20. · 1.95 Impact Factor
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ABSTRACT: Aim: FG020326, a novel imidazole derivative, is a potent multidrug-resistance (MDR) modulator in vitro and in vivo. However, FG020326 is insoluble. PEDLLA-FG020326 is a FG020326-loaded nanoparticle formed with diblock copolymers of poly (ethylene glycol)-block-poly (D,L-lactic acid) (PEG:PDLLA, PEDLLA) that can solubilize FG020326. This work was intended to evaluate the pharmacodynamics of PEDLLA-FG020326 on reversing MDR in vitro and in vivo.
Acta Pharmacologica Sinica 05/2007; 28(6):913-920. · 1.95 Impact Factor
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ABSTRACT: Aim: FG020326, a novel imidazole derivative, is a potent multidrug-resistance (MDR) modulator in vitro and in vivo. However, FG020326 is insoluble. PEDLLA-FG020326 is a FG020326-loaded nanoparticle formed with diblock copolymers of poly (ethylene glycol)-block-poly (D,L-lactic acid) (PEG:PDLLA, PEDLLA) that can solubilize FG020326. This work was intended to evaluate the pharmacodynamics of PEDLLA-FG020326 on reversing MDR in vitro and in vivo.Methods: Cytotoxicity was determined by tetrazolium assay. The intracellular accumulation and efflux of doxorubicin (Dox) were detected by fluorescence spectrophotometry. The function of P-glycoprotein was examined by Rhodamine 123 (Rh123) accumulation detected by flow cytometry. The KBv200 cell xenograft model was established to investigate the effect of PEDLLA-FG020326 on reversing MDR in vivo.Results: PEDLLA-FG020326 and FG020326 exhibited 56.4- and 35.9-fold activity in reversing KBv200 cells to vincristine (VCR) resistance, respectively and 14.98-and 7.64-fold to Dox resistance, respectively. PEDLLA-FG020326 was much stronger than FG020326, resulting in the increase of Dox and Rh123 accumulation and the decrease of intracellular Dox extrusion in KBv200 cells. Importantly, PEDLLA-FG020326 exhibited more powerful activity than FG020326 in enhancing the effect of VCR against KBv200 cell xenografts in nude mice, but did not appear more toxic. Conclusion: The pharmacodynamics of FG020326 was improved by incorporating it into a micellar nanoparticle formed with PEG-block-PDLLA copolymers.
Acta Pharmacologica Sinica 05/2007; 28(6):913 - 920. · 1.95 Impact Factor
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ABSTRACT: To study the feasibility of MRI of human colon adenocarcinoma cell line (Lovo) labeled with superparamagnetic iron oxide(SPIO) nanoparticles in vitro.
Lovo cells (5 × 10(5) and 1 × 10(6)) were cultured in medium containing different SPIO nanoparticles (50 microl and 500 microl). Transmission electron microscopy was used to observe cellular ultrastructure and to determine the uptake and distribution of particles in Lovo cells at 1-, 3-, 6-hours. MRI of Lovo cells was performed with T1WI, T2WI sequences. Unlabeled cells were used as controls.
Uptake of SPIO nanoparticles occurred within 6 hours. On T1 weighted imaging, there was no significant difference in signal intensity between the experimental groups and the control group. On T2 weighted imaging, there was no significant difference in signal intensity between the experimental groups and the control group after culture of 1 h. Signal intensity began to decrease in 1 × 10(6) Lovo cells labeled with 500 microl SPIO nanoparticle after 3 hours culture. Signal intensity decreased in all the experimental groups after 6 hours culture.
Human colon adenocarcinoma cell line (Lovo) can be labeled with SPIO nanoparticles, and the labeled cells can be imaged with MRI equipment.
Zhonghua wei chang wai ke za zhi = Chinese journal of gastrointestinal surgery 14(1):27-30.
