[1] Christian Albrechts Univ Kiel, Inst Mat Sci, D-24143 Kiel, Germany
[2] Saarland Univ, Dept Paediat Cardiol, D-66421 Homburg, Germany
[3] Saarland Univ, Dept Trauma Hand & Reconstruct Surg, D-66421 Homburg, Germany
[4] INM Leibniz Inst New Mat, Campus D2 2, D-66123 Saarbrucken, Germany
[5] Univ Clin Essen, Dept Anat, D-45147 Essen, Germany
[6] Saarland Univ, Dept Anat & Cell Biol, D-66421 Homburg, Germany