[1] INEB Inst Engn Biomed, Oporto, Portugal
[2] Univ Porto, Fac Engn, Dept Met & Mat Engn, P-4100 Oporto, Portugal
[3] Ohio State Univ, Dept Biomed Engn, Columbus, OH 43210 USA
[4] Univ Porto, Fac Med Dent, Lab Farmacol & Biocompatibilidade, P-4100 Oporto, Portugal