Methods and apparatus are provided for treating damaged tissue using
apparatus that atraumatically delivers a bioactive agent within the
tissue, wherein the apparatus provides a column of stem cells may be
advanced simultaneously with a needle during needle insertion, and then
held stationary or injected at low pressure while retracting the needle.
Alternatively, the needle may employ electromotive forces, or to change a
dimension of the needle, to expel the bioactive agent into the needle
track.