Multi-layered polydopamine coatings for the immobilization of growth factors onto highly-interconnected and bimodal PCL/HA-based scaffolds

Maria Godoy Gallardo, Núria Portolés-Gil, Ana M. López-Periago, Concepción Domingo, Leticia Hosta-Rigau*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

For bone tissue engineering applications, scaffolds that mimic the porous structure of the extracellular matrix are highly desirable. Herein, we employ a PCL/HA-based scaffold with a double-scaled architecture of small pores coupled to larger ones. To improve the osteoinductivity of the scaffold, we incorporate two different growth factors via polydopamine (PDA) coating. As a first step, we identify the maximum amount of PDA that can be deposited onto the scaffold. Next, to allow for the deposition of a second PDA layer which, in turn, will allow to increase the loading of growth factors, we incorporate a dithiol connecting layer. The thiol groups covalently react with the first PDA coating through Michael addition while also allowing for the incorporation of a second PDA layer. We load the first and second PDA layers with bone morphogenic protein-2 (BMP2) and vascular endothelial growth factor (VEGF), respectively, and evaluate the osteogenic potential of the functionalised scaffold by cell viability, alkaline phosphatase activity and the expression of three different osteogenesis-related genes of pre-seeded human mesenchymal stem cells. Through these studies, we demonstrate that the osteogenic activity of the scaffolds loaded with both BMP2 and VEGF is greater than scaffolds loaded only with BMP2.
Importantly, the osteoinductivity is higher when the scaffolds are loaded with BMP2 and VEGF in two different
PDA layers. Taken together, these results indicate that the as-prepared scaffolds could be a useful construct for
bone-tissue applications.
Original languageEnglish
Article number111245
JournalMaterials Science and Engineering C: Materials for Biological Applications
Volume117
Number of pages15
DOIs
Publication statusPublished - 2020

Keywords

  • Bone tissue engineering
  • Co-delivery
  • Growth factors
  • Multi-layers
  • Polydopamine
  • Supercritical CO2

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