Apparatus and Methods for Controlling Cellular Development

Abstract

According to one aspect and example, a method for facilitating cellular interactions in biological tissue provides controllable activation of a selected type of stem cell among a plurality of cell types present in the tissue. The method includes various steps including the introduction of a microbial opsin into a region of the tissue that includes a selected type of stem cell, by expressing the microbial opsin the stem cell. A light source is then introduced near the stem cell, and the light source is used to controllably activate the light source to direct pulses of illumination from the light source to the selected type of stem cell, for selectively controlling the growth and development of the stem cell in a manner that is independent of the growth and development of the other types of cells.

1 - 12 . (canceled) 
     
     
         13 . A structure comprising:
 a) a tissue culture matrix that comprises stem cells or progenitor cells, at least some of which express a light-activated polypeptide;   b) a light source configured to provide light pulses to cells in the tissue culture matrix; and   c) a pulse generator for generating control signals that control the light source.   
     
     
         14 . The structure of  claim 13 , wherein the light-activated polypeptide is a channel rhodopsin. 
     
     
         15 . The structure of  claim 13 , wherein the light-activated polypeptide is an NpHR polypeptide. 
     
     
         16 . The structure of  claim 13 , wherein the tissue culture matrix includes a porous barrier membrane that is configured to prevent cell migration out of the tissue culture matrix and to prevent clumping in other portions of the engineered matrix. 
     
     
         17 . The structure of  claim 13 , wherein the tissue culture matrix includes a porous barrier membrane comprising polyethylene terephthalate and having pores of a diameter between approximately 3 μm and 7 μm. 
     
     
         18 . The structure of  claim 13 , further including a photo detector for sensing light provided by an indicator of an action potential. 
     
     
         19 . The structure of  claim 13 , wherein the progenitor cells comprise one or more of neuronal progenitor cells, glial progenitor cells, and vascular progenitor cells. 
     
     
         20 . The structure of  claim 13 , wherein the stem cells are neural stem cells, pluripotent stem cells, or induced pluripotent stem cells. 
     
     
         21 . The structure of  claim 13 , wherein the light-activated polypeptide is encoded by a nucleotide sequence operably linked to a cell type-specific promoter.