[51]

TISSUE ENGINEERED CARDIAC AND SKELETAL MUSCLE: LESSONS LEARNED FROM MICROPATTERNED COLLAGEN AND MICROGRAVITY.  L. Terracio¹, W. Yan¹, R. Price², M. Yost², G. Bolin³, and D.G. Simpson³.  ¹New York University, College of Dentistry, New York, NY.  ²University of South Carolina, School of Medicine, Columbia, SC.  ³Virginia Commonwealth University, Richmond VA.

   The focal loss of muscular tissue, as a result of a congenital defect or a disease process, alters the unique architectural arrangement of the heart or skeletal muscle and impairs its function.  Conventional surgical techniques cannot begin to adequately restore the subtle structural and functional relationships that exist in the healthy tissue.  If this is to be accomplished it must ultimately be undertaken at the cellular level.  We have used micropatterned native collagen templates under microgravity culture conditions, either on the Space Shuttle or in the RCCS Bioreactor to tissue engineer cardiac and skeletal muscle that retains many of the characteristics seen in vivo.  The collagen template was formed using a solution of ice cold, neutral type I collagen and applying it to a substrate with a sterile nylon brush, at a concentration of O.62μg/mm².  The substrate is then tipped and the collagen solution is allowed to drain across the surface and to polymerize at 37 єC for 1 hour.  Either neonatal cardiac myocytes or skeletal satellite cells were plated on the collagen templates and maintained for 72-96 hr under standard culture conditions prior to the addition of more cells under microgravity conditions.  Both cell types plated on the collagen templates attached, elongated and assumed the pattern of the collagen, which was aligned along a single axis.  When additional cells were added to the cultures in ground-based control experiments, they formed irregular aggregates that did not integrate into the template of aligned cells.  However, when the cells were added in microgravity, they attached to the aligned monolayer of cells, aligned and formed multilayered tissue-like structures.  In both cases the constructs exhibited characteristics of differentiated cardiac and skeletal muscle.