Selective bone cell adhesion on formulations containing carbon nanofibers.

Bone cell adhesion on novel carbon nanofibers and polycarbonate urethane/carbon nanofiber (PCU/CNF) composites is investigated in the present in vitro study. Carbon nanofibers have exceptional theoretical mechanical properties (such as high strength to weight ratios) that, along with possessing nanoscale fiber dimensions similar to crystalline hydroxyapatite found in physiological bone, suggest strong possibilities for use as an orthopedic/dental implant material. The effects of select properties of carbon fibers (specifically, dimension, surface energy, and chemistry) on osteoblast, fibroblast, chondrocyte, and smooth muscle cell adhesion were determined in the present in vitro study. Results provided evidence that smaller-scale (i.e., nanometer dimension) carbon fibers promoted osteoblast adhesion. Adhesion of other cells was not influenced by carbon fiber dimensions. Also, smooth muscle cell, fibroblast, and chondrocyte adhesion decreased with an increase in either carbon nanofiber surface energy or simultaneous change in carbon nanofiber chemistry. Moreover, greater weight percentages of high surface energy carbon nanofibers in the PCU/CNF composite increased osteoblast adhesion while at the same time decreased fibroblast adhesion.