Tough magnesium phosphate-based 3D-printed implants induce bone regeneration in an equine defect model
Nasim Golafshan1, Elke Vorndran2, Stefan Zaharievski1
1Department of Orthopedics, University Medical Center Utrecht, GA, Utrecht, the Netherlands; Regenerative Medicine Utrecht, Utrecht, the Netherlands.
Biomaterials
|September 15, 2020
Summary
This study developed 3D-printed magnesium phosphate (MgP) and polycaprolactone (PCL) bone implants. These novel implants demonstrate enhanced shape ability, mechanical strength, and promote significant bone regeneration in vivo.
Area of Science:
- Biomaterials Science
- Tissue Engineering
- Orthopedic Surgery
Background:
- Developing biodegradable bone substitutes for complex bone defects remains a challenge.
- Magnesium phosphate (MgP) ceramics doped with strontium (Sr2+) show promise for bone formation but lack suitable mechanical properties and shapeability.
- Existing MgP materials are difficult to fabricate into large, complex geometries required for load-bearing applications.
Purpose of the Study:
- To fabricate and characterize novel 3D-printed bone implants using strontium-doped magnesium phosphate (MgPSr) and polycaprolactone (PCL).
- To evaluate the printability, mechanical properties, and in vitro and in vivo bone regenerative potential of the MgPSr-PCL composite scaffolds.
Main Methods:
- Extrusion-based 3D printing was used to create MgPSr-PCL composite scaffolds.
- Scaffolds (MgPSr-PCL30) were characterized for printability, macroporosity, and compressive strength.
- In vitro studies assessed bone formation without osteo-inductive supplements.
- In vivo studies utilized an equine tuber coxae model over 6 months, with analysis via micro-CT and histology.
Main Results:
- MgPSr-PCL30 scaffolds exhibited excellent printability for large structures (>780 mm3) with ~40% interconnected macroporosity.
- The implants achieved a compressive strength of 4.3 MPa, supporting 50 loading cycles without plastic deformation.
- In vitro tests confirmed MgPSr-PCL30 scaffolds promoted bone formation.
- In vivo results demonstrated significant bone regeneration in implanted defects over 6 months, with no bone formation in empty defects.
Conclusions:
- A novel polymer-modified MgP ceramic material and 3D printing process were developed for bone implants.
- The MgPSr-PCL30 material significantly improves shape ability and load-bearing capacity compared to pure MgP ceramics.
- These 3D-printed scaffolds effectively induce new bone formation, offering a promising solution for treating bone defects.
