eCM (Eur Cell Mater / e Cells & Materials) Not-for-Profit Open Access
Created by Scientists, for Scientists
 ISSN:1473-2262         NLM:100973416 (link)         DOI:10.22203/eCM

2019   Volume No 37 – pages 60-73

Title: Accelerated bone formation by biphasic calcium phosphate with a novel sub-micron surface topography

Authors: R Duan, LA van Dijk, D Barbieri, F de Groot, H Yuan, JD de Bruijn

Address: Bronkhorstlaan 10, building 48, 3723 MB Bilthoven, the Netherlands

E-mail: j.d.debruijn at

Abstract: Osteoinductive calcium phosphate (CaP) bone grafts have equivalent performance to autografts in repairing critical-size bone defects. The osteoinductive potential of CaP is linked to the size of the surface topographical features. In the present study, two novel biphasic calcium phosphate (BCP) bone grafts were synthesised with either sub-micron- (BCP<µm) or micron-scale (BCPµm) needle-shaped surface topography and compared to dimensionally similar tricalcium phosphate (TCP) with grain-shaped surface structures (TCP<µm and TCPµm). To clarify the possible function of the surface morphology (needle-like vs. grain-like) in initiating bone formation, the four CaP test materials were physicochemically characterised and implanted for 12 weeks in the dorsal muscle of beagles. The sub-micron needle-shaped topography of BCP<µm triggered earlier bone formation (3-6 weeks) as compared to the grain-shaped surface topography of TCP<µm, which formed bone at 6-9 weeks. After 12 weeks, the amount of induced bone formation in both materials was equivalent, based on histomorphometry. The micron-sized needle-shaped surface topography of BCPµm led to limited formation of new bone tissue, whereas its counterpart, TCPµm with grain-shaped surface topography, failed to trigger de novo bone formation. The relative strength of the parameters affecting CaP-driven bone induction was as follows: surface feature size > surface feature morphology > substrate chemistry. BCP materials with needle-shaped sub-micron surface topography gave rise to accelerated bone formation and slower rate of resorption than a comparable TCP. These characteristics may be translated to improve bone healing in orthotopic defects.

Key Words: Osteoinduction, calcium phosphate, bone graft, surface topography, sub-micron-scale, needle crystal.

Publication date: January 28th 2019

Article download: Pages 60-73 (PDF file)

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