Tubular cationized pullulan hydrogels as local reservoirs for plasmid DNA

1 - ArticleIn the present study, we measured the ability of various cationized pullulan tubular hydrogels to retain plasmid DNA, and tested the ability of retained plasmid DNA to transfect vascular smooth muscle cells (VSMCs). Cationized pullulans were obtained by grafting at different charge densities ethylamine (EA) or diethylaminoethyl-amine (DEAE) on the pullulan backbone. Polymers were characterized by elemental analysis, acid-base titration, size exclusion chromatography, Fourier-transform infrared spectroscopy, and proton nuclear magnetic resonance. The complexation of cationized pullulans in solution with plasmid DNA was evidenced by fluorescence quenching with PicoGreen. Cationized pullulans were then chemically crosslinked with phosphorus oxychloride to obtain tubular cationized pullulan hydrogels. Native pullulan tubes did not retain loaded plasmid DNA. In contrast, the ability of cationized pullulan tubes to retain plasmid DNA was dependent on both the amine content and the type of amine. The functional integrity of plasmid DNA in cationized pullulan tubes was demonstrated by in vitro transfection of VSMCs. Hence, cationized pullulan hydrogels can be designed as tubular structures with high affinity for plasmid DNA, which may provide new biomaterials to enhance the efficiency of local arterial gene transfer strategies. (c) 2007 Wiley Periodicals, Inc

Pro-angiogenic effect of RANTES-loaded polysaccharide-based microparticles for a mouse ischemia therapy

International audiencePeripheral arterial disease results from the chronic obstruction of arteries leading to critical hindlimb ischemia. The aim was to develop a new therapeutic strategy of revascularization by using biodegradable and biocompatible polysaccharides-based microparticles (MP) to treat the mouse hindlimb ischemia. For this purpose, we deliver the pro-angiogenic chemokine Regulated upon Activation, Normal T-cell Expressed and Secreted (RANTES)/CCL5 in the mouse ischemic hindlimb, in solution or incorporated into polysaccharide-based microparticles. We demonstrate that RANTES-loaded microparticles improve the clinical score, induce the revascularization and the muscle regeneration in injured mice limb. To decipher the mechanisms underlying RANTES effects in vivo, we demonstrate that RANTES increases the spreading, the migration of human endothelial progenitor cells (EPC) and the formation of vascular network. The main receptors of RANTES i.e. CCR5, syndecan-4 and CD44 expressed at endothelial progenitor cell surface are involved in RANTES-induced in vitro biological effects on EPC. By using two RANTES mutants, [E66A]-RANTES with impaired ability to oligomerize, and [44 AANA 47]-RANTES mutated in the main RANTES-glycosaminoglycan binding site, we demonstrate that both chemokine oligomerization and binding site to glycosaminoglycans are essential for RANTES-induced angiogenesis in vitro. Herein we improved the muscle regeneration and revascularization after RANTES-loaded MP local injection in mice hindlimb ischemia

RANTES/CCL5-induced pro-angiogenic effects depend on CCR1, CCR5 and glycosaminoglycans

International audienceAtherosclerosis involves angiogenesis and inflammation with the ability of endothelial cells and monocytes to respond to chemokines. We addressed here by in vitro and in vivo approaches, the role of the chemokine Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES)/CCL5 on angiogenesis through its receptors CCR1, CCR5, syndecan-1 (SDC-1), syndecan-4 (SDC-4) and CD-44. Our data demonstrate that RANTES/CCL5 is pro-angiogenic in a rat subcutaneous model. This RANTES/CCL5-activity may be related to the in vitro promotion of endothelial cell migration, spreading and neo-vessel formation. RANTES/CCL5-mediated angiogenesis depends at least partly on Vascular Endothelial Growth Factor (VEGF) secretion by endothelial cells, since this effect is decreased when endothelial cells are incubated with anti-VEGF receptor antibodies. RANTES/CCL5-induced chemotaxis is mediated by matrix metalloproteinase-9. We demonstrate that specific receptors of RANTES/CCL5 such as G protein-coupled receptors CCR1 and CCR5, and heparan sulfate proteoglycans, SDC-1, SDC-4 or CD-44, play a major role in RANTES/CCL5-induced angiogenic effects. By the use of two RANTES/CCL5 mutants, [E66A]-RANTES/CCL5 with impaired ability to oligomerize, and [44AANA47]-RANTES/CCL5 mutated in the main RANTES/CCL5-glycosaminoglycan (GAG) binding site, we demonstrate that chemokine oligomerization and binding to GAGs are essential in RANTES/CCL5-induced angiogenic effects. According to these results, new therapeutic strategies based on RANTES/CCL5 can be proposed for neo-angiogenesis after vascular injury. Mutants of RANTES/CCL5 may also represent an innovative approach to prevent the angiogenesis associated with the formation of atherosclerotic plaque

A fine structural modification of glycosaminoglycans is correlated with the progression of muscle regeneration after ischaemia: towards a matrix-based therapy?

Critical limb ischaemia often leads to amputation of the limb and potential mortality. Moreover, there are still significant problems with current therapeutic treatments, according to poor revascularisation of degenerated tissue probably due to modifications within the microenvironment. This study is focused on the changes of structure and bioactivity of glycosaminoglycans (GAGs), especially heparan sulphate (HS) and chondroitin sulphate (CS) in rat Extensor Digitorum Longus (EDL) muscle after ischaemia. Male Wistar rats were subjected to ischaemic-injury by ligation of the neurovascular trunk accompanying EDL-tendon. After 4, 8, 15, 21, 60 and 90 d, the rats were sacrificed and the muscles were collected and submitted to histological, biochemical and gene expression assays. We demonstrated that ischaemia induced modification of expression of enzymes involved in GAG biosynthesis which correlated with significant changes in HS and CS structural features such as size and sulphation pattern. These major structural changes are associated to modifications of GAG abilities to bind growth factors and to modulate cell activity. Moreover, a CS hallmark of injury is maintained as well after the regeneration process. Finally, we showed the relevance of the role of this glycanic matrix remodelling, since a GAG mimetic treatment accelerated muscle repair after ischaemia