Modulating the Biomechanical Properties of Engineered Connective Tissues by Chitosan-Coated Multiwall Carbon Nanotubes

Int J Nanomedicine. 2021 Feb 15:16:989-1000. doi: 10.2147/IJN.S289107. eCollection 2021.


Background: Under certain conditions, the physiological repair of connective tissues might fail to restore the original structure and function. Optimized engineered connective tissues (ECTs) with biophysical properties adapted to the target tissue could be used as a substitution therapy. This study aimed to investigate the effect of ECT enforcement by a complex of multiwall carbon nanotubes with chitosan (C-MWCNT) to meet in vivo demands.

Materials and methods: ECTs were constructed from human foreskin fibroblasts (HFF-1) in collagen type I and enriched with the three different percentages 0.025, 0.05 and 0.1% of C-MWCNT. Characterization of the physical properties was performed by biomechanical studies using unidirectional strain.

Results: Supplementation with 0.025% C-MWCNT moderately increased the tissue stiffness, reflected by Young's modulus, compared to tissues without C-MWCNT. Supplementation of ECTs with 0.1% C-MWCNT reduced tissue contraction and increased the elasticity and the extensibility, reflected by the yield point and ultimate strain, respectively. Consequently, the ECTs with 0.1% C-MWCNT showed a higher resilience and toughness as control tissues. Fluorescence tissue imaging demonstrated the longitudinal alignment of all cells independent of the condition.

Conclusion: Supplementation with C-MWCNT can enhance the biophysical properties of ECTs, which could be advantageous for applications in connective tissue repair.

Keywords: chitosan; collagen-based tissue scaffold; engineered connective tissue; mechanical properties; multiwall carbon nanotubes.

MeSH terms

  • Animals
  • Biomechanical Phenomena
  • Cattle
  • Cell Line
  • Chitosan / chemistry
  • Chitosan / pharmacology*
  • Connective Tissue / physiology*
  • Elastic Modulus
  • Fibroblasts / drug effects
  • Humans
  • Nanotubes, Carbon / chemistry*
  • Tissue Engineering*


  • Nanotubes, Carbon
  • Chitosan

Grants and funding

NK and MA: The project was kindly funded and supported by the Palestinian Ministry of Higher Education (fund ID number ANNU-MoHE-1819-Sc010), the Deanship of Scientific Research at An-Najah National University (ANNU-1920-Sc016) and by the German Academic Exchange Service (DAAD). This work was further funded by the German Research Foundation (DFG) by the project IRTG 1816 to GLS. AR was funded by the Higher Education Commission of Pakistan. SL is supported by the German Center for Cardiovascular Research (DZHK). W.H.Z is supported by the German Research Foundation (DFG; CRC 1002 C04 and S01, IRTG 1816), the German Center for Cardiovascular Research (DZHK), and the Leducq Foundation.