Macrophage response to methacrylate conversion using a gradient approach.

Journal Article (Journal Article)

Incomplete conversion, an ongoing challenge facing photopolymerized methacrylate-based polymers, affects leachables as well as the resulting polymer network. As novel polymers and composites are developed, methods to efficiently screen cell response to these materials and their properties, including conversion, are needed. In this study, an in vitro screening methodology was developed to assess cells cultured directly on cross-linked polymer networks. A gradient in methacrylate double bond conversion was used to increase the experimental throughput. A substrate of 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl] propane (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) was prepared with a conversion ranging from 43.0% to 61.2%. Substrates aged for 7 days had no significant differences in surface roughness or hydrophilicity as a function of conversion. Leachables were detectable for at least 7 days using UV absorption, but their global cytotoxicity was insignificant after 5 days of aging. Thus, RAW 264.7 macrophage-like cells were cultured on aged substrates to evaluate the cell response to conversion, with possible contributions from the polymer network and local leachables. Conversions of 45% and 50% decreased viability (via calcein/ethidium staining) and increased apoptosis (via annexin-V staining). No significant changes (p>0.05) in tumor necrosis factor-alpha and interleukin-1beta gene expression, as measured by quantitative, real-time reverse transcription-polymerase chain reaction, were seen as conversion increased. Thus, conversions greater than 50% are recommended for equimolar BisGMA/TEGDMA. The ability to distinguish cell response as a function of conversion is useful as an initial biological screening platform to optimize dental polymers.

Full Text

Duke Authors

Cited Authors

  • Lin, NJ; Bailey, LO; Becker, ML; Washburn, NR; Henderson, LA

Published Date

  • March 2007

Published In

Volume / Issue

  • 3 / 2

Start / End Page

  • 163 - 173

PubMed ID

  • 17140868

Electronic International Standard Serial Number (EISSN)

  • 1878-7568

International Standard Serial Number (ISSN)

  • 1742-7061

Digital Object Identifier (DOI)

  • 10.1016/j.actbio.2006.10.001


  • eng