Electrospun fibers/branched-clusters as building units for tissue engineering

Abstract Although electrospun templates are effective at mimicking the extracellular matrix (ECM) of native tissue due to the tailorability of parameters such as fiber diameter, polymer composition, and drug loading, these templates are often limited with regards to cell infiltration and the tailorability of the microenvironments within the structures. Thus, there remains a need for a flexible threedimensional template system which could be combined with cell suspensions to promote three-dimensional tissue regeneration, and ultimately allow cells to freely reorganize and modify their microenvironment. In this study, a mincing process was designed and optimized to create mixtures of electrospun fibers/branched-clusters for use as fundamental tissue engineering building units. These fiber/branched-cluster elements were characterized with regards to fiber and branch lengths, and a method was optimized to combine them with normal human dermal fibroblasts (nHDFs) in culture to create interconnected template constructs. Sectioning and imaging of these constructs revealed cell/fiber integration as well as even cell distribution throughout the construct interior. These fiber/branched-cluster elements represent an innovative flexible tissue regeneration template system.