From implantation to degradation - are poly (l-lactide)/multiwall carbon nanotube composite materials really cytocompatible?

In this study a possible cell-materials interaction occurring after biomaterial implantation was evaluated in respect to PLLA/MWCNT nanocomposite and human cells. No cytotoxic compounds were released from nanocomposites as evaluated by extract test. The material was found to be biocompatible for human bone marrow stromal cells (HBMC adhesion, proliferation, activation and differentiation). The MWCNT that may be released during nanocomposite degradation did not induce adverse responses in HBMC. However, the MWCNT and lactic acid, possible nanocomposite degradation products, revealed to be cytotoxic for HBMC in a synergistic way.174