A new series of triblock [dendritic poly(L-lysine)]-block-PLLA-block-[dendritic poly(L-lysine)]s (DL(2) -PLLA-DL(2) ) with PLLA block lengths of 11.5-26.5 and double 2-generation PLL dendrons DL(2) as model cationic amphiphiles were synthesized and characterized. Their CAC, self-aggregation and plasmid DNA binding affinities in pure water and PBS were studied. The PLLA block length dependence of particle size, morphology and ξ potential for organized pDNA/amphiphile polyplex aggregates were examined. Finally, toxicities of these DL(2) -PLLA-DL(2) amphiphiles and their polyplexes were assayed by MTT with HeLa, SMMC-7721 and COS-7 cells, and COS-7 cell luciferase and eGFP gene transfection efficacies with these amphiphiles as the delivery carriers were investigated. 相似文献
The present study expands the versatility of cationic poly(2-oxazoline) (POx) copolymers as a polyethylene glycol (PEG)-free platform for gene delivery to immune cells, such as monocytes and macrophages. Several block copolymers are developed by varying nonionic hydrophilic blocks (poly(2-methyl-2-oxazoline) (pMeOx) or poly(2-ethyl-2-oxazoline) (pEtOx), cationic blocks, and an optional hydrophobic block (poly(2-isopropyl-2-oxazoline) (iPrOx). The cationic blocks are produced by side chain modification of 2-methoxy-carboxyethyl-2-oxazoline (MestOx) block precursor with diethylenetriamine (DET) or tris(2-aminoethyl)amine (TREN). For the attachment of a targeting ligand, mannose, azide-alkyne cycloaddition click chemistry methods are employed. Of the two cationic side chains, polyplexes made with DET-containing copolymers transfect macrophages significantly better than those made with TREN-based copolymer. Likewise, nontargeted pEtOx-based diblock copolymer is more active in cell transfection than pMeOx-based copolymer. The triblock copolymer with hydrophobic block iPrOx performs poorly compared to the diblock copolymer which lacks this additional block. Surprisingly, attachment of a mannose ligand to either copolymer is inhibitory for transfection. Despite similarities in size and design, mannosylated polyplexes result in lower cell internalization compared to nonmannosylated polyplexes. Thus, PEG-free, nontargeted DET-, and pEtOx-based diblock copolymer outperforms other studied structures in the transfection of macrophages and displays transfection levels comparable to GeneJuice, a commercial nonlipid transfection reagent. 相似文献
Nucleic acid drugs have great potential to treat many devastating aliments, but their application has been hindered by the lack of efficacious and nontoxic delivery vehicles. Here, a new library of poly(glycoamidoamine)s (D1-D4, G1-G4, and M1-M4) has been synthesized by polycondensation of esterified d-glucaric acid (D), dimethyl-meso-galactarate (G), and d-mannaro-1,4:6,3-dilactone (M) with diethylenetriamine (1), triethylenetetramine (2), tetraethylenepentamine (3), and pentaethylenehexamine (4). The stereochemistry of the carbohydrate hydroxyl groups and the number of amine units have been systematically changed in an effort to examine how the polymer chemistry affects the plasmid DNA (pDNA) binding affinity, the compaction of pDNA into nanoparticles (polyplexes), the material cytotoxicity, and the efficacy of nucleic acid delivery. The polymers with four secondary amines (D4, G4, and M4) between the carbohydrates were found to have the highest pDNA binding affinity and the galactarate polymers generally yielded the smallest polyplexes. Delivery studies with pDNA containing the firefly luciferase or beta-galactosidase reporter genes in BHK-21, HeLa, and HepG2 cells demonstrated that all of the poly(glycoamidoamine)s deliver pDNA without cytotoxicity. Polymers D4, G4, and M4 displayed the highest delivery efficiency, where G4 was found to be a particularly effective delivery vehicle. Heparin competition assays indicated that this may be a result of the higher pDNA binding affinity displayed by G4 as compared to D4 and M4. Polyplexes formed by polymers with weaker pDNA affinities may dissociate at the cell surface due to interactions with negatively charged glycosaminoglycans, which would cause a decrease in the number of polyplexes that are endocytosed. 相似文献
In this work, we present the preparation of water‐soluble poly(methacrylate)s with pendant cationic L ‐lysines PHMLs(6–30 K). Plasmid DNA binding affinity as well as particle sizes and zeta potentials of the polyplexes were examined for these PHML vectors, and their cytotoxicities were assayed with HeLa cells by CCK‐8 and lactate dehydrogenase kits. Gene transfection efficacy and intracellular uptake of the polyplexes by the PHML vectors were also studied with HeLa cells. As a result, it was revealed that the low cytotoxic PHMLs tended to exhibit gene transfection efficiencies significantly higher than those of the linear structural PLL (15–30 K) control, in particular the molecular weight of a PHML vector remarkably influenced its pDNA binding affinity, transfection efficacy and intracellular uptake of the polyplexes.
In this report, four new poly(d-glucaramidoamine)s (1-4) have been designed to lower the toxicity of conventional polymeric nucleic acid delivery vehicles by incorporating a carbohydrate comonomer within a polyethylenimine (PEI)-like backbone. Polymers 1-4 were synthesized via polycondensation of esterified d-glucaric acid and four different amine-containing comonomers [diethylenetriamine (1), triethylenetetramine (2), tetraethylenepentamine (3), and pentaethylenehexamine (4)] in methanol. Viscometry and NMR studies suggest that the polymers are mostly linear (for 1-4, the alpha value in the Mark-Houwink-Sakurada equation = 0.6-0.7), thus indicating that polymerization occurs predominantly through the primary amines with a low degree of branching off the secondary amines. Results of gel electrophoresis shift assays show that polymers 1-4 bind pDNA at N/P ratios of 5, 3, 2, and 2, respectively. Also, dynamic light scattering and TEM experiments indicate that 1-4 compact DNA into nanoparticles (polyplexes) between 140 and 440 nm at an N/P ratio of 30. Furthermore, polyplexes formed with 1-4 deliver pDNA (plasmid DNA) containing the firefly luciferase reporter gene to BHK-21 cells in a nontoxic and highly efficient manner (as determined by luciferase gene expression). In particular, polymer 4 reveals very high delivery efficiency (equivalent to linear PEI). This result may be due in part to the "proton sponge" hypothesis proposed by Behr et al. Polymers containing amines that are protonated in the endosomal pH range (between about 7.4-5.0) reveal enhanced gene delivery profiles. 相似文献
A novel amine‐functionalized polycarbonate was synthesized and its excellent gene transfection ability in vitro is demonstrated. In the framework of adapting the cationic polycarbonate for in vivo gene delivery applications, here the design and synthesis of biodegradable block copolymers of poly(ethylene glycol) (PEG) and amine‐functionalized polycarbonate with a well‐defined molecular architecture and molecular weight is achieved by metal‐free organocatalytic ring‐opening polymerization. Copolymers in triblock cationic polycarbonate‐block‐PEG‐block‐cationic polycarbonate and diblock PEG‐block‐cationic polycarbonate configurations, in comparison with a non‐PEGylated cationic polycarbonate control, are investigated for their influence on key aspects of gene delivery. Among the polymers with similar molecular weights and N content, the triblock copolymer exhibit more favorable physicochemical (i.e., DNA binding, size, zeta‐potential, and in vitro stability) and biological (i.e., cellular uptake and luciferase reporter gene expression) properties. Importantly, the various cationic polycarbonate/DNA complexes are biocompatible, inducing minimal cytotoxicities and hemolysis. These results suggest that the triblock copolymer is a more useful architecture in future cationic polymer designs for successful systemic therapeutic applications. 相似文献
Chirality is a key factor in the biological activity of many biomolecules. Poly(L-lysine)(PLL), a polypeptide synthesized from L-lysine, is one of the mostly used cationic polymers for gene delivery. The effect of chirality of polylysine(PL) on its gene delivery remains unknown. Herein, we prepared three polylysines(PLs) with the similar molecular weight but different backbone chiralities including poly(L-lysine)(PLL), poly(D-lysine)(PDL) and poly(DL-lysine)(PDLL). The side chains of each PL were modified with propylene oxide(PO) of different chiralities including(R)PO,(S)PO and(R,S)PO. These PL-POs with distinct chirality in main and side chains could condense p DNA into polyplexes. The polyplexes had approximately the same size, zeta potential and binding ability, but showed distinct gene transfection efficiency. We found that the PLs of L-configuration in the main chain had higher transfection efficiency than that of D or DL configuration due to their faster cellular uptake, while the side chain chirality had no effect on transfection efficiency. 相似文献
The development of polymers with low toxicity and efficient gene delivery remains a significant barrier of nonviral gene therapy. Modification and tuning of chemical structures of carriers is an attractive strategy for efficient nucleic acid delivery. Here, polyplexes consisting of plasmid DNA (pDNA) and dodecylated or non‐dodecylated polysuccinimide (PSI)‐based polycations are designed, and their transfection ability into HeLa cells is investigated by green fluorescent protein (GFP) expressing cells quantification. All cationic polymers show lower cytotoxicity than those of branched polyethyleneimine (bPEI). PSI and bPEI‐based polyplexes have comparable physicochemical properties such as size and charge. Interestingly, a strong interaction between dodecylated polycations and pDNA caused by the hydrophobic moiety is observed in dodecylated PSI derivatives. Moreover, the decrease of GFP expression is associated with lower dissociation of pDNA from polyplexes according to the heparin displacement assay. Besides, a hydrophobization of PSI cationic derivatives with dodecyl side chains can modulate the integrity of polyplexes by hydrophobic interactions, increasing the binding between the polymer and the DNA. These results provide useful information for designing polyplexes with lower toxicity and greater stability and transfection performance. 相似文献
