Tissue-Engineered Liver Microreactor as an in vitro surrogate assay for gene delivery (Ad.CMV.EGFP delivery)

The isolation and culture of cells in vitro alters the structural and functional properties that they exhibit as part of an organized tissue, and could be one of the factors that lead to the lack of correlation between in vitro and in vivo gene delivery. This issue is of particular importance in the case of liver. Hepatocytes undergo a rapid loss of liver-specific function, cell viability and cyto-architecture when maintained under conventional culture conditions. This problem indicates the necessity for an organized in vitro tissue culture system, in order to improve the predictive value of in vitro assays for the performance of gene delivery vectors in vivo. The Tissue-Engineered Liver Microreactor developed in our lab provides a perfused 3D liver culture system. We are pursuing this system as a potential in vitro assay for gene delivery studies. Using an adenoviral vector and enhanced Green Fluorescent Protein as a reporter, we can detect and quantify gene delivery efficiency and levels of gene expression in this 3D system, by the application of techniques such as two-photon microscopy and spectrometry.