Bioengineering (Sep 2017)

Lysine-Grafted MCM-41 Silica as an Antibacterial Biomaterial

  • María F. Villegas,
  • Lorena Garcia-Uriostegui,
  • Ofelia Rodríguez,
  • Isabel Izquierdo-Barba,
  • Antonio J. Salinas,
  • Guillermo Toriz,
  • María Vallet-Regí,
  • Ezequiel Delgado

DOI
https://doi.org/10.3390/bioengineering4040080
Journal volume & issue
Vol. 4, no. 4
p. 80

Abstract

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This paper proposes a facile strategy for the zwitterionization of bioceramics that is based on the direct incorporation of l-lysine amino acid via the ε-amino group onto mesoporous MCM-41 materials. Fourier transform infrared (FTIR) studies of lysine-grafted MCM-41 (MCM-LYS) simultaneously showed bands at 3080 and 1540 cm−1 and bands at 1625 and 1415 cm−1 corresponding to -NH3+/COO− pairs, which demonstrate the incorporation of the amino acid on the material surface keeping its zwitterionic character. Both elemental and thermogravimetric analyses showed that the amount of grafted lysine was 8 wt. % based on the bioceramic total weight. Moreover, MCM-LYS exhibited a reduction of adhesion of S. aureus and E. coli bacteria in 33% and 50%, respectively at physiological pH, as compared with pristine MCM-41. Biofilm studies onto surfaces showed that lysine functionalization elicited a reduction of the area covered by S. aureus biofilm from 42% to only 5% (88%). This research shows a simple and effective approach to chemically modify bioceramics using single amino acids that provides zwitterionic functionality, which is useful to develop new biomaterials that are able to resist bacterial adhesion.

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