GRAPHENE OXIDE REINFORCED PEPTIDE AMPHIPHILE HYDROGELS VIA CO- ASSEMBLY


Erol Ö., Guler M. O.

ICBASET 2022: International Conference on Basic Sciences, Engineering and Technology, İstanbul, Turkey, 25 - 28 August 2022, pp.22

  • Publication Type: Conference Paper / Summary Text
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.22
  • Gazi University Affiliated: Yes

Abstract

Due to its outstanding properties such as high surface area, mechanical strength, biocompatibility, a two-dimensional layered carbon nanomaterial, graphene oxide (GO) finds enormous potential application in the biomedical field including bioelectronics, imaging, drug delivery, and tissue engineering (Erol et al., 2018).  The cell culture and tissue engineering fields especially require three-dimensional (3D) biocompatible and biodegradable scaffolds and GO can be used as a nanofiller to design 3D hybrid hydrogels (Wychowaniec et al., 2018). Peptide amphiphile (PA) molecules are obtained by conjugating hydrophobic tails to short peptide sequences and can self-assemble into nanofiber networks. PAs can be synthesized in different functionalities by adding binding sites to regulate cell behavior, including proliferation, differentiation, and protein synthesis to promote specific tissue regeneration. PAs can form 3D hydrogel structure similar to the natural extracellular matrix (ECM) in terms of elasticity and porosity. However, they possess low load bearing capabilities. Due to its mechanical properties, GO can support cell differentiation in-vitro. In this study, to obtain mechanically reinforced, biocompatible and ECM mimicking platforms, GO particles were introduced to positively (Lauryl-VVAGKKK-Am, K3-PA) and negatively (Lauryl-VVAGEEE-Am, E3-PA) charged PAs which form gel upon mixing them. Oppositely charged PAs were prepared via solid phase peptide synthesis method and characterized by LC-MS measurements. The simple co-assembly strategy was applied by mixing oppositely charged PAs in the presence of a defined amount of GO (GO:PA ratios were 1:2, 1:5 and 1:10 by mass and K3-PA:E3-PA ratio was 1:1). The mechanical properties of the prepared PA/GO composite hydrogels were determined by time, strain, and frequency sweep oscillatory measurements. Rheological measurements revealed that mechanical performance of the composite hydrogel was increased with increasing GO content. Elastic modulus of the GO reinforced composite hydrogel was observed as 4.5 times higher than non-reinforced PA hydrogel while both stabilities were determined as close to each other.