Area-specific cell stimulation via surface-mediated gene transfer using apatite-based composite layers.

Surface-mediated gene transfer systems using biocompatible calcium phosphate (CaP)-based composite layers have attracted attention as a tool for controlling cell behaviors. In the present study we aimed to demonstrate the potential of CaP-based composite layers to mediate area-specific dual gene transfer and to stimulate cells on an area-by-area basis in the same well. For this purpose we prepared two pairs of DNA-fibronectin-apatite composite (DF-Ap) layers using a pair of reporter genes and pair of differentiation factor genes.

Improved gene transfer efficiency of a DNA-lipid-apatite composite layer by controlling the layer molecular composition.

Surface-mediated nonviral gene transfer systems using biocompatible apatite-based composite layers have potential use in tissue engineering applications. Herein, we investigated a relatively efficient system based on a DNA-lipid-apatite composite layer (DLp-Ap layer): an apatite (Ap) layer with immobilized DNA and lipid (Lp) complexes (DLp complexes). DLp-Ap layers were fabricated on substrates using supersaturated calcium phosphate coprecipitation solutions supplemented with DLp complexes, and the molecular compositions of the DLp-Ap layers were controlled by varying the net DNA concentrations and Lp/DNA ratios in the coprecipitation solutions.

Coprecipitation of DNA-lipid complexes with apatite and comparison with superficial adsorption for gene transfer applications.

Apatite can mediate gene transfer into cells by serving as a safe and biocompatible immobilization matrix for DNA and transfection reagents. Recently, an apatite layer that immobilized DNA-lipid complexes was prepared by a coprecipitation process in a supersaturated calcium phosphate solution. This composite layer (DNA-lipid-apatite layer) showed a higher gene transfer capability than an apatite layer with superficially adsorbed DNA-lipid complexes (DNA-lipid-adsorbed apatite layer).

Fabrication of DNA-antibody-apatite composite layers for cell-targeted gene transfer.

Surface-mediated gene transfer systems using apatite (Ap)-based composite layers have received increased attention in tissue engineering applications owing to their safety, biocompatibility and relatively high efficiency. In this study, DNA-antibody-apatite composite layers (DA-Ap layers), in which DNA and antibody molecules are immobilized within a matrix of apatite nanocrystals, were fabricated using a biomimetic coating process. They were then assayed for their gene transfer capability for application in a specific cell-targeted gene transfer.

Fabrication of a DNA-lipid-apatite composite layer for efficient and area-specific gene transfer.

A surface-mediated gene transfer system using biocompatible apatite-based composite layers has great potential for tissue engineering. Among the apatite-based composite layers developed to date, we focused on a DNA-lipid-apatite composite layer (DLp-Ap layer), which has the advantage of relatively high efficiency as a non-viral system. In this study, various lipid transfection reagents, including a newly developed reagent, polyamidoamine dendron-bearing lipid (PD), were employed to prepare the DLp-Ap layer, and the preparation condition was optimized in terms of efficiency of gene transfer to epithelial-like CHO-K1 cells in the presence of serum.

BMP-2 gene-fibronectin-apatite composite layer enhances bone formation.

Background: Safe and efficient gene transfer systems are needed for tissue engineering. We have developed an apatite composite layer including the bone morphogenetic protein-2 (BMP-2) gene and fibronectin (FB), and we evaluated its ability to induce bone formation.

Methods: An apatite composite layer was evaluated to determine the efficiency of gene transfer to cells cultured on it.

Control of gene transfer on a DNA-fibronectin-apatite composite layer by the incorporation of carbonate and fluoride ions.

Gene transfer techniques are useful tools for controlling cell behavior, such as proliferation and differentiation. We have recently developed an efficient area-specific gene transfer system using a DNA-fibronectin-apatite composite layer (DF-Ap layer). In this system, partial dissolution of the composite layer is likely to be a crucial step for gene transfer.