There still remains a need for new methods of healing large bone defects, i.e., gaps in bone tissue that are too big to naturally heal. Bone regrowth scaffolds can fill the bone gap and enhance the bone regeneration by providing cells with a support to for new tissue formation. Coating of the scaffolds surface with nanocrystalline hydroxyapatite may enhance the osteoinductivity or osteoconductivity of such scaffolds. Here we present the sonocoating method to coat scaffolds with bioactive hydroxyapatite nanoparticles. We show a method, where the material to be coated is immersed in a colloidal suspension of nanoparticles with mean sizes of 10 nm and 43 nm in water, and high-power ultrasound waves are applied to the suspension for 15 min at 30 °C. High power ultrasounds lead to growth of cavitation bubbles in liquid, which implode at a critical size. The implosion energy propels the nanoparticles towards the material surface, causing their attachment to the scaffold. Using this technique, we produced a uniform layer of nanohydroxyapatite particles of thickness in the range 200 to 300 nm on two types of scaffolds: a porous β-TCP ceramic scaffold and a 3D-printed scaffold made of PCL fibers. In vivo tests in rabbits confirmed that the novel coating strongly stimulated new bone tissue formation, with new bone tissue occupying 33% for the nHAP-coated PCL scaffold and 68% for the nHAP-coated β-TCP after a 3-month test. The sonocoating method leads to formation of a bioactive layer on the scaffolds at temperature close to room temperature, very short time and in water. It is a green technological process, promising for bone tissue regeneration applications.
|Number of pages||16|
|Journal||Materials Science and Engineering C|
|State||Published - Jun 2019|
Bibliographical noteFunding Information:
This work was financed by the Eranet project MATERA ERA-NET ‘SONOSCA’ MATERA/BBM-2557 “Sonochemical technology for bioactive bone regeneration scaffold production”. The research studies were conducted using equipment funded by the project CePT (reference: POIG.02.02.00-14-024/08), financed by the European Regional Development Fund within the Operational Programme “Innovative Economy” for years 2007–2013. We would like to personally acknowledge Mr. Jan Mizeracki, Barbara Ostrowska, PhD for the technical and scientific support of this research study.
- Bone scaffolds
- Surface modification
- Ultrasonic cavitation