CP-PEI-FA was prepared as an effective vector for in vitro and in vivo tumor-targeted gene delivery. The structures of the polymers were characterized, and their DNA condensation capability, particle sizes, zeta potentials, cytotoxicity and in vitro/in vivo transfection were examined. The cytotoxicity of CP-PEI-FA was significantly lower than that of PEI 25 kDa and close to that of PEI 1200. The in vitro transfection of CP-PEI-FA was tested in C6 and HeLa cells (FR-positive cells) and A549 cells (FR-negative cells). CP-PEI-FA showed a high targeting specificity and good gene transfection efficiency in FR-positive cells. These results indicate that CP-PEI-FA is a safe and effective polyplex-forming agent for both in vitro and in vivo transfection of plasmid DNA. 相似文献
In order to enhance the gene delivery efficiency and decrease cytotoxicity of polyplexes, copolymers consisting of branched polyethyleneimine (PEI) 25 kDa grafted with Pluronic (F127, F68, P105) were successfully synthesized using a simple two-step procedure. The copolymers were tested for cytotoxicity and DNA condensation and complexation properties. Their polyplexes with plasmid DNA were characterized in terms of DNA size and surface charge and transfection efficiency. The complex sizes were below 300 nm, which implicated their potential for intracellular delivery. The Pluronic-g-PEI exhibited better condensation and complexation properties than PEI 25 kDa. The cytotoxicity of PEI was strongly reduced after copolymerization. The Pluronic-g-PEI showed lower cytotoxicity in three different cell lines (Hela, MCF-7, and HepG2) than PEI 25 kDa. pGL3-lus was used as a reporter gene, and the transfection efficiency was in vitro measured in HeLa cells. Compared with unmodified PEI 25 kDa Pluronic-g-PEI showed much higher transfection efficiency. These results demonstrate that polyplexes prepared using a combined strategy of surface crosslinking and grafted with Pluronic seem to provide promising properties as stable, high transfection efficiency vectors. 相似文献
A new poly(aminoester) (EPAE-FA) containing folic acid and amino groups in the backbone and side chain was synthesized. EPAE-FA self-assembled readily with the plasmid DNA (pCMV-βgal) in HEPES buffer and was characterized by dynamic light scattering, zeta potential, fluorescence images, and XTT cell viability assays. To evaluate the transfection effect of graft ratio of FA on the EPAE system, EPAE-FA polymers with two different graft ratios (EPAE-FA12k and EPAE-FA14k) were also prepared. This study found that all EPAE-FA polymers were able to bind plasmid DNA and yielded positively charged complexes with nano-sized particles ( < 200 nm). To assess the transfection efficiency mediated by EPAE and EPAE-FA polymers, we performed in vitro transfection activity assays using FR-negative (COS-7) and FR-positive (HeLa) cells. The EPAE-FA12k/DNA and EPAE-FA14k/DNA complexes were able to transfect HeLa cell in vitro with higher transfection efficiency than PEI25k/DNA at the similar weight ratio. These results demonstrated that the introduction of FA into EPAE system had a significant effect on transferring ability for FR-positive cells (HeLa). Examination of the cytotoxicity of PEI25k and EPAE-FA system revealed that EPAE-FA system had lower cytotoxicity. In this paper, EPAE-FA seemed to be a novel cationic poly(aminoester) for gene delivery and an interesting candidate for further study. 相似文献
A facile approach for polymer gene carriers was used to construct hyaluronic acid (HA) shielding polyplexes due to the electrostatic interaction. By adding HA to PEI/DNA complexes, the ξ-potential of ternary polyplexes was changed from positive to negative. Spherical particles with diameter about 250nm were observed. Ethidium bromide exclusion assay indicated that the electrostatic complexation was loosened after addition of HA. However, DNA disassembly did not occur. The proper reason was that the intensity of negative charges was not strong enough to release DNA from the complexes in our experiment. The stability of PEI/DNA/HA polyplexes in physiological condition was improved and the cytotoxicity was reduced. Comparing with PEI/DNA polyplexes, the uptake and transfection efficiency of HA shielding polyplexes was lower for HEK293T cells probably due to the reduced adsorptive endocytosis, whereas it was higher for HepG2 cells due to HA receptor mediated endocytosis. This facile approach to constructing HA shielding polyplexes might have great potential application in non-viral gene delivery research and tumor therapy. 相似文献
Low efficiency is often observed in the delivery of DNA vaccines. The use of superparamagnetic nanoparticles (SPIONs) to deliver genes via magnetofection could improve transfection efficiency and target the vector to its desired locality. Here, magnetofection was used to enhance the delivery of a malaria DNA vaccine encoding Plasmodium yoelii merozoite surface protein MSP1(19) (VR1020-PyMSP1(19)) that plays a critical role in Plasmodium immunity. The plasmid DNA (pDNA) containing membrane associated 19-kDa carboxyl-terminal fragment of merozoite surface protein 1 (PyMSP1(19)) was conjugated with superparamagnetic nanoparticles coated with polyethyleneimine (PEI) polymer, with different molar ratio of PEI nitrogen to DNA phosphate. We reported the effects of SPIONs-PEI complexation pH values on the properties of the resulting particles, including their ability to condense DNA and the gene expression in vitro. By initially lowering the pH value of SPIONs-PEI complexes to 2.0, the size of the complexes decreased since PEI contained a large number of amino groups that became increasingly protonated under acidic condition, with the electrostatic repulsion inducing less aggregation. Further reaggregation was prevented when the pHs of the complexes were increased to 4.0 and 7.0, respectively, before DNA addition. SPIONs/PEI complexes at pH 4.0 showed better binding capability with PyMSP1(19) gene-containing pDNA than those at neutral pH, despite the negligible differences in the size and surface charge of the complexes. This study indicated that the ability to protect DNA molecules due to the structure of the polymer at acidic pH could help improve the transfection efficiency. The transfection efficiency of magnetic nanoparticle as carrier for malaria DNA vaccine in vitro into eukaryotic cells, as indicated via PyMSP1(19) expression, was significantly enhanced under the application of external magnetic field, while the cytotoxicity was comparable to the benchmark nonviral reagent (Lipofectamine 2000). 相似文献
GalactosylatedN-3-guanidinopropylmethacrylamide-co-poly (ethylene glycol) methacrylate copolymers (galactosylated GPMA-co-PEGMA, GGP) were developed in order to promote transfection efficiency in the presence of serum in this report. First of all, the galactosylated PEGMA-co-GPMA copolymers were prepared via aqueous reversible addition – fragmentation chain transfer polymerization (RAFT) of poly (ethylene glycol) methacrylate (PEGMA) with long circulating chain segment and N-3-aminopropyl methacrylamide (APMA) followed by galactosylation and guanidinylation. After that, GGP/plasmid DNA complexes were examined by a dynamic light scattering and gel electrophoresis. It is showed that GGP copolymers have effective condensing ability. The cytotoxicity of GGP was measured by MTT assay. It was found that all the GGP/plasmid DNA complexes had less cytotoxic effects on HepG2 cells than HeLa cells, and the galactose groups reduced the cytotoxicity of complexes with high charge ratios to HepG2 cells. Finally, the transfection efficiency of the galactosylated PEGMA-co-GPMA copolymers was investigated by luciferase expression assay. The results revealed that the copolymers with galactose groups more than 5.83% could induce the asialoglycoprotein (ASGP) receptor mediated transfection, which improved the transfection efficiency in target cells. The GPMA-co-PEGMA copolymers with 54.57% hydrophilic chain segment PEG should prevent the aggregation of protein on the GGP/pDNA complexes, and GGP with 7.94% galactose graft exhibited the highest transfection in the presence of serum. 相似文献
Poly(
,
-lactic acid) (PLA)-based particles, obtained by the emulsification–diffusion process, were surface-modified by electrostatic adsorption of poly(ethylenimine) (PEI). The amount of immobilized PEI and the conformation of the polycation at the interface were dependent on the ionic strength of the media. In the absence of salt, or at low ionic strength, the adsorbed amounts of PEI, the surface charge and the critical concentration for coagulation (CCC) of the modified particles were lower than when the adsorption was achieved at elevated ionic strength. Moreover, at low salt concentration, isotherms were of Langmuir type, suggesting the formation of monolayers. The differences in PEI surface conformation had consequences on the DNA binding capacity of the particles, on the plasmid DNA conformation at the interface and on the DNA release in various media. When PEI was adsorbed in a 50 mM phosphate buffer, the amount of bound plasmid and the strength of binding were higher than when PEI was adsorbed in water. From these differences in physico-chemical properties, one can expect differences in transfection or immunization performances of the vectors. 相似文献
Polyethylenimine (PEI) is a well-known cationic polymer which has high transfection efficiency due to its buffering effect. However, nondegradability, cytotoxicity, aggregation, and short-circulation time in vivo still need to be overcome for a successful gene delivery. Degradable, hyperbranched poly(ester amine)s (PEAs) based on poloxamer diacrylate and low molecular weight branched PEI, were successfully synthesized and evaluated as a nonviral gene carrier. The PEAs were obtained in significant yields through Michael type addition reaction of diacrylate monomers and low molecular weight branched PEI. Analysis of degradation products by the reduction in molecular weight demonstrated that PEAs degrade in a controlled fashion. The PEA showed good DNA binding ability and the sizes of complexes under physiological condition were below 150 nm, implicating its potential for intracellular delivery. It showed lower cytotoxicity in three different cell lines (A549, 293T, and HepG2) compared with PEI 25K. PEAs showed much higher transfection efficiencies in three cell lines compared with PEI 25K and PEI 1.8K, and revealed little serum dependency in A549 cell line when the content of poloxamer in the PEA was increased up to 30%. 相似文献
Bovine serum albumin(BSA) was utilized to assemble with the binary complexes of poly(vinylpyrrolidone)-graft-poly(2- dimethylaminoethyl methacrylate)(PVP-g-PDMAEMA)/DNA formed by layer-by-layer electrostatic interactions to screen the residual surface positive charges of complexes.The coating of BSA was able to decrease the zeta potential of binary complexes nearly to electroneutrality without interfering with DNA condensation ability.The ternary complexes of BSA/PVP-g-PDMAEMA/ DNA demonstrated lower cytotoxicity compared with the binary complexes and also maintained high gene transfection efficiency in HepG2 cells. 相似文献
A family of thermoresponsive cationic copolymers (TCPs) that contain branched PEI 25 K as the cationic segment and poly(MEO(2)MA-co-OEGMA(475)) as the thermosensitive block (TP) is prepared. The DNA binding capability, physicochemical properties, and biological performance of the TCPs are studied. All of these TCPs can condense DNA to form polyplexes with diameters of 150-300 nm and zeta potentials of 7-32 mV at N/P ratios between 12 and 36. The length of TP block is a key factor for shielding the positive surface charge of the polyplexes and protecting them against protein adsorption. TCPs with a higher TP content have a lower cytotoxicity while the best transfection performance is achieved by the TCPs with longest TP length, reaching a level of the intact PEI 25 K in the presence of serum. 相似文献
A new derivative of polyamidoamine and polyethylenimine, G2.5‐PEI 423 or G1.5‐PEI 423, is prepared by an amidation reaction of PAMAM G2.5 or PAMAM G1.5 using PEI 423. The polycations show a great ability to combine with pDNA to form complexes, which protect the pDNA from nuclease degradation. The polymers display stronger buffer capacity and lower cytotoxicity. The complexes have particle sizes of 120–180 nm and zeta potentials of 20–40 mV. The G2.5‐PEI 423 complexes display much higher transfection efficiencies than PAMAM G5 and Lipo‐2k, and the G1.5‐PEI 423 complexes display higher transfection efficiencies than PAMAM G4 and PEI‐25k. The complexes possess better serum‐resistant capacity. The G2.5‐PEI 423 has a great potential to be used as a serum‐resistant gene vector.
The leading principle of non-viral delivery systems for gene therapy is to mediate high levels of gene expression with low cytotoxicity. Nowadays, biodegradable nanoparticles formulated with poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) were wildly developed. However, the relative lower gene transfection efficiency and higher cytotoxicity still remained critical problems. To address these limitations, PLA-PEG nanoparticles have been composited with other components in their formulation. Here, a novel cationic lipid, 6-lauroxyhexyl lysinate (LHLN), was fabricated onto PLA-PEG nanoparticles as a charge modifier to improve the transfection efficiency and cytotoxicity. The obtained cationic LHLN modified PLA-PEG nanoparticles (LHLN-PLA-PEG NPs) could condense pDNA thoroughly via electrostatic force, leading to the formation of the LHLN-PLA-PEG NPs/pDNA complexes (NPs/DNA complexes). The nanoparticles obtained have been characterized in relation to their physicochemical and biological properties, and the results are extremely promising in terms of low cell toxicity and high transfection efficiency. These results indicated that the novel cationic LHLN modified PLA-PEG nanoparticles could enhance gene transfection in vitro and hold the potential to be a promising non-viral nanodevice. 相似文献
