In Vitro Toxicity of Biomaterials Determined with Cell Density, Total Protein, Cell Cycle Distribution and Adenine Nucleotides

Abstract

Inhibition of cell growth is the most commonly used endpoint for in vitro toxicity of biomaterials. The use of several different endpoints might however generate more information concerning the nature of the toxicity. Thus, we examined the toxicity of two biomaterials, Polyvinylchloride (PVC) and Polyoximethene (POM), with different selected endpoints. The influence of cell growth on these endpoints was also investigated. Water extracts from the polymeric materials were tested on the continuous cell line L-929. Cell density, total protein, total protein per cell, fraction of cells in G₀/G₁- or S-phase, the concentration of ATP, ADP and AMP were used as endpoints. The PVC material did not significantly influence any of these endpoints until after 72 hours of exposure and the main part of the toxicity at 72 hours was related to higher proliferation rate in control cultures. After the cells had been incubated for 8 hour with POM the main toxic effect was on the energy parameters. In conclusion the PVC material was less toxic than the POM material. Our results also implies that the choice of endpoint will influence the evaluation of cytotoxicity.