An immunomodulatory and osteogenic bacterial cellulose scaffold for bone regeneration via regulating the immune microenvironment

Int J Biol Macromol. 2024 Nov;281(Pt 3):136375. doi: 10.1016/j.ijbiomac.2024.136375. Epub 2024 Oct 9.

Abstract

Creating a bone homeostasis microenvironment that balances osteogenesis and immunity is a substantial challenge for bone regeneration. Here, we prepared an immunomodulatory and osteogenic bacterial cellulose scaffold (FOBS) via a facile one-pot approach. The aldehyde groups were generated via selective oxidation of the hydroxyl groups of bacterial cellulose, offering the bonding sites for dopamine through a Schiff base reaction. At the same time, the deposition of Ca2+ and PO43- was promoted on the aldehyde cellulose scaffold because of the high affinity of the catechol moiety for Ca2+. Compared with that of the unmodified scaffold, the hydroxyapatite content of FOBS increased by 47.1 % according to the ICP results. Interestingly, FOBS regulated the immune microenvironment to accelerate the conversion of M1 to M2 macrophages. The expressions of ARG-1 and Dectin-1 (M2) in the FOBS group increased by >100 %. The expression of osteogenic differentiation of BMSCs was also upregulated. In a rat cranial defect model, the BV/TV of FOBS was significantly increased. Further immunohistochemical analysis revealed that an improved immune microenvironment promoted the osteogenic differentiation of stem cells in vivo. This work provides an effective and easy-to-operate strategy for the development of the bone tissue engineering scaffolds.

Keywords: Bacterial cellulose; Bone regeneration; Dopamine; Immunomodulation; Mineralization.

MeSH terms

  • Animals
  • Bacteria
  • Bone Regeneration* / drug effects
  • Cell Differentiation / drug effects
  • Cellular Microenvironment / drug effects
  • Cellulose* / chemistry
  • Cellulose* / pharmacology
  • Durapatite / chemistry
  • Durapatite / pharmacology
  • Immunomodulation / drug effects
  • Male
  • Mesenchymal Stem Cells / cytology
  • Mesenchymal Stem Cells / drug effects
  • Mesenchymal Stem Cells / metabolism
  • Osteogenesis* / drug effects
  • Rats
  • Rats, Sprague-Dawley
  • Tissue Engineering / methods
  • Tissue Scaffolds* / chemistry

Substances

  • Cellulose
  • Durapatite