Strains in Magnetically Aligned Collagen Scaffolds as Determined by Displacement-Encoded MRI

Collagen is the most abundant structural protein in a broad range of tissues, including ligament, cartilage, and bone. Collagen-based tissue constructs, including those with defined fibril alignment, have shown considerable potential for repair and regeneration of diseased collagen-rich tissues [1,2], where fibril ultrastructure of constructs emulate the native tissue counterpart. Magnetic alignment of collagen is an established method to control fiber orientation without undesirable changes in molecular stability and structure [5]. To date, studies concerning the magnetic alignment of collagen have shown the ability of fibril alignment to drive preferential cell growth characteristics [6]. While the bulk mechanical characteristics due to alignment has been investigated in our laboratory (data not shown), the mechanical strain throughout the interior of the scaffolds has not been investigated. Knowledge of internal strains is required to determine the degree that fiber alignment affects spatiotemporal mechanics of microenvironments within the collagen structures. Spatially-dependent mechanics, which could be tailored based on unique fabrication methods that control fibril alignment in three dimensions, would be expected to directly influence local cell-matrix interactions.