Combined Shikonin-Loaded MPEG-PCL Micelles Inhibits Effective Transition of Endothelial-to-Mesenchymal Cells

Int J Nanomedicine. 2022 Sep 24:17:4497-4508. doi: 10.2147/IJN.S374895. eCollection 2022.

Abstract

Introduction: Shikonin is well known for its anti-inflammatory activity in cardiovascular diseases. However, the application of shikonin is limited by its low water solubility and poor bioavailability. Methoxy poly (ethylene glycol)-b-poly (ε-caprolactone) (MPEG-PCL) is considered a promising delivery system for hydrophobic drugs. Therefore, in this study, we prepared shikonin-loaded MPEG-PCL micelles and investigated their effect on endothelial-to-mesenchymal transition (EndMT) induced by inflammatory cytokines.

Methods: Shikonin was encapsulated in MPEG-PCL micelles using an anti-solvent method and the physiochemical characteristics of the micelles (particle size, zeta potential, morphology, critical micelle concentration (CMC), drug loading and encapsulation efficiency) were investigated. Cellular uptake of micelles in human umbilical vein endothelial cells (HUVECs) was evaluated using fluorescence microscopy. In vitro EndMT inhibition was explored in HUVECs by quantitative real-time PCR analysis.

Results: The average particle size of shikonin-loaded MPEG-PCL micelles was 54.57±0.13 nm and 60 nm determined by dynamic light scattering and transmission electron microscopy, respectively. The zeta potential was -6.23±0.02 mV. The CMC of the micelles was 6.31×10-7mol/L. The drug loading and encapsulation efficiency were 0.88±0.08% and 43.08±3.77%, respectively. The MPEG-PCL micelles significantly improved the cellular uptake of cargo with low water solubility. Real-time PCR analysis showed that co-treatment with TNF-α and IL-1β successfully induced EndMT in HUVECs, whereas this process was significantly inhibited by shikonin and shikonin-loaded MPEG-PCL micelles, with greater inhibition mediated by the shikonin-loaded MPEG-PCL micelles.

Conclusion: Shikonin-loaded MPEG-PCL micelles significantly improved the EndMT-inhibiting effect of the free shikonin. MPEG-PCL is suitable for use more generally as a lipophilic drug carrier.

Keywords: EndMT; inflammation; shikonin; shikonin-loaded MPEG-PCL micelles.

MeSH terms

  • Anti-Inflammatory Agents / therapeutic use
  • Drug Carriers / chemistry
  • Endothelial Cells*
  • Humans
  • Micelles*
  • Naphthoquinones
  • Polyesters / chemistry
  • Polyethylene Glycols / chemistry
  • Tumor Necrosis Factor-alpha
  • Water

Substances

  • Anti-Inflammatory Agents
  • Drug Carriers
  • Micelles
  • Naphthoquinones
  • Polyesters
  • Tumor Necrosis Factor-alpha
  • methoxy poly(ethylene glycol-co-epsilon-caprolactone)
  • Water
  • shikonin
  • Polyethylene Glycols

Grants and funding

This study was supported by the National Natural Science Foundation of China (No. 81873520) and the Natural Science Foundation of Shaanxi Province (2019JM-394).