Structural hierarchy of biomimetic materials for tissue engineered vascular and orthopedic grafts

Gelatine gels and gelatine/elastin gels have been prepared to be used in tissue engineered vascular grafts. Optical microscopy and atomic force microscopy (AFM) revealed that the gelatine formed nanofibrils as in soft collagen tissues. The gelatine/elastin gels were nanocomposites with flat elastin nanodomains embedded in the gelatine matrix mimicking the structure of the tunica media in arteries. Gelatine/"hydroxyapatite" (HA) nanocomposites were prepared with the in situ production of "HA" in solution. AFM revealed "HA" solid nanoparticles of about 20 nm size embedded in the gelatine matrix, which formed a hierarchical structure similar to that of the collagen matrix in bone. The application of amagnetic field of 9.4 T resulted in the elongation and orientation of gelatine particles and orientation of gelatine microfibrils in a direction perpendicular to that of the magnetic field. (c) 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008.