Surface-mediated gene transfer from nanocomposites of controlled texture

Abstract

Safe and efficient gene delivery would have great potential in gene therapy and tissue engineering, but synthetic biomaterial surfaces endowed with efficient gene-transferring functions do not yet exist. Inspired by naturally occurring biomineralization processes, we co-precipitated DNA with inorganic minerals onto cell-culture surfaces. The DNA/mineral nanocomposite surfaces obtained not only supported cell growth but also provided high concentrations of DNA in the immediate microenvironment of the cultured cells. Gene transfer from the engineered surfaces was as efficient as an optimized commercial lipid transfection reagent; in addition, the extent of gene transfer was adjustable by varying the mineral composition. DNA/mineral nanocomposite surfaces represent a promising system for enhancing gene transfer and controlling the extent of gene transfer for various biomedical applications, including tissue engineering or gene therapy of bone.

Matrices and scaffolds for DNA delivery in tissue engineering

“…In the maximal expression conditions, 90% of the plasmid was bound to CaP, while 78% of the CaP bound plasmid actually resulted in complexed DNA in a size ranging between 25 and 50 nm. The removal of magnesium and addition of surplus calcium resulted in higher DNA precipitation and retention on the surface relative to the standard simulated body fluid [110]. The mineral solution lacking magnesium resulted in plate-like nanocomposite surfaces, consisting of many nanocrystals, in contrast with the larger spherical features (500 nm diameter) formed in the presence of Mg 2+ .…”

“…Calcium phosphates (CaP) have been deposited onto polymer scaffolds for bone tissue engineering, and separately have been used as transfection reagents [108,109]. For immobilization, plasmid is co-precipitated with CaP as nanocrystalline CaP phases onto a surface [110]. The CaP vector is relatively non-toxic to cells, and the levels of transgene expression depend on the Ca/P ratio (maximal expression at ratio of 100-300) and the mixing conditions [109].…”

Novel gene-transferring scaffolds having a cell adhesion molecule–DNA–apatite nanocomposite surface

“…As shown in Figure 3, the gene-transferring system using the LD-Ap layer developed in this work is superior in regard to its efficiency over the previous systems using a D-Ap layer. 12 It should be noted that the efficiency of gene transfer on the LD-Ap layer was equivalent to, or even higher (see MG-63 in Figure 3) than that mediated using a commercial lipidbased transfection reagent (Lipofectamine) applied using the manufacture's recommended optimum conditions. [15][16][17][18] supplemented with 40 mg ml À1 of DNA and 0, 10, 20 or 40 mg ml À1 of laminin.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] A gene-transferring system mediated by a particulate DNA-calcium phosphate composite [1][2][3] is safer than viral [4][5][6] and lipid-based [7][8][9] systems, but its transferring efficiency is comparatively low. To enhance the gene-transferring efficiency, a surface-mediated genetransferring system derived from a DNA-apatite composite (D-Ap) layer has been developed.…”

“…To enhance the gene-transferring efficiency, a surface-mediated genetransferring system derived from a DNA-apatite composite (D-Ap) layer has been developed. 12 In this system, regions of high DNA concentration are produced locally around cells, and this enhances the gene-transferring efficiency. In this work, the cell adhesion molecule, laminin, 13,14 was immobilized on a D-Ap layer to enhance further the gene-transferring efficiency by strengthening a cell's attachment and facilitating its spreading on a coating's surface.…”