Fibrin−Lipoplex System for Controlled Topical Delivery of Multiple Genes

Abstract

Nonviral gene delivery via natural biomacromolecules show great promise as controlled release systems while avoiding the associated drawbacks with viral gene delivery such as immunogenicity and safety issues. Here, a fibrin-lipoplex system for topical delivery of multiple genes is described. In vitro release analysis showed efficient retention of the lipoplexes in the fibrin scaffold. The biomolecular interaction between fibrinogen and liposomes was investigated qualitatively using surface plasmon resonance. The strong binding between the lipoplexes and the fibrinogen component of the scaffold was observed and that could explain the in vitro release profile observed in our studies. Both in vitro and in vivo transfection studies using multiple reporter genes were performed to establish the bioactivity of released lipoplexes. The ability of the lipoplexes to transfect fibroblasts in vitro was shown to be maintained even after extended periods of encapsulation within the scaffold. Furthermore, in a rabbit ear ulcer model, the fibrin-lipoplex system was shown to have significantly higher transfection efficiency for two reporter genes at day 7 when compared to lipoplexes alone, suggesting that this fibrin-lipoplex system is suitable for extended release of lipoplexes for topical gene delivery applications.

Vascularization of the Dermal Support Enhances Wound Re-Epithelialization by In Situ Delivery of Epidermal Keratinocytes

“…Plasmid DNA [42][43][44][45] and recombinant viruses 46,47 have also been incorporated into fibrin hydrogels by our group and others, and they may be also used in this setting to promote vascularization. For the most part, genetic modification in this setting is local to the cells that populate the dermis during the granulation tissue phase of wound healing, for example, macrophages, fibroblasts, and endothelial cells.…”

Liposomes in tissue engineering and regenerative medicine

“…There are two ways to immobilize liposomes at the surface of the scaffolds: (i) non-specific immobilization, which means that the liposomes are adsorbed at the surface of the scaffold and are easily removed during the cell culture at each medium exchange; (ii) specific immobilization, which means that the liposomes are covalently bound at the surface of the scaffold, increasing their stability. A scaffold system that uses naturally occurring interactions between liposomes and the fibrinogen was used to obviate the need for chemical conjugation [126]. To facilitate liposome adsorption, scaffold surfaces were coated with various extracellular matrix proteins, which were able to transfect a higher number of cells, while at the same time reducing the amount of DNA required [127].…”

Fibrin As a Scaffold for Delivery of GDNF Overexpressing Stem Cells to the Adult Rat Brain

“…This was assessed using volumetric analysis of the GFP-expressing graft which we have previously shown to be a reliable method for assessing the overall survival of these cells in the rat brain 52 . Our laboratory has shown that the composition of this fibrin scaffold provides an excellent substrate to facilitate viral and non-viral therapeutic gene delivery 34,[36][37][38][39][40] .…”