The response of human osteoblasts on bovine xenografts with and without hyaluronate used in bone augmentation
Qasim SSB, Trajkovski B, Zafiropoulos GG. J Biomater Sci Polym Ed. 2024 Feb 12:1-18.


It was the aim of the study to investigate the biological activity of human osteoblasts in response to four different bovine bone substitute materials. Specifically, it was the goal to assess cell viability, proliferation, expression of osteogenic differentiation- as well as mineralization markers of osteoblasts cultured on bone grafts containing hyaluronic acid (cerabone® plus) and bone substitutes composed of bone granules only (cerabone®, Straumann® Xenograft and Bio-Oss®).


Osteoblasts were cultured together with particulate bone grafting materials for up to 28 days using a specifically designed and self-prepared seeding ring. Cell viability and expression of Alkaline Phosphatase (ALP) were assessed and quantified using cell assays. Calcium and collagen deposition by the osteoblasts were measured using different staining. Cell proliferation was examined by live cell imaging. In addition, confocal laser scanning- and scanning electron microscopy were performed to evaluate cell morphology and microstructure of the bone substitutes.


Cell adhesion and cell morphology

  • Osteoblasts were well attached and spread on all examined bone substitute materials
  • Cells showed rounded morphologies with cytoplasmic extensions
  • Each bone substitute had a unique pattern of cells spread and morphology
  • Cell adhesion on cerabone® plus occurred faster and with a higher level of organization than on the other bone substitutes

Spreading behavior of human osteoblasts on cerabone® plus (Confocal laser scanning microscopy. Green: cell actin cytoskeleton; blue: cell nuclei. Image scaled at 100 µm with a magnification of 10x.)

Osteoblast viability and ALP expression

  • Cell viability increased from day 4 to day 10 for all bone substitutes (p<.05)
  • ALP expression increased from day 14 to day 21 for all bone substitutes (p<.0001)
  • cerabone® plus showed higher ALP activity than all other bone substitutes

Collagen deposition

  • Increased from day 14 to 28 for all bone substitutes (p<.0001)
  • Osteoblasts cultured on cerabone® plus showed highest collagen deposition

Calcium deposition

  • Increased from day 14 to 28 for all bone substitutes (p<.01 and p<.0001 respectively)
  • Highest calcium deposition by the cells in the cerabone® plus group


All investigated bone substitute materials showed increases in cellular viability, proliferation and mineralization markers of human osteoblasts.

The different ultrastructural properties of the bone substitutes influenced cell adhesion, cell motility and mineral deposition.

cerabone® plus demonstrated the highest levels of osteoblast viability, ALP activity and calcium and collagen deposition, which can be primarily attributed to the contained hyaluronic acid.