Multiscale osteointegration as a new paradigm for the design of calcium phosphate scaffolds for bone regeneration.
The role of macropore size (>100 microm) and geometry in synthetic scaffolds for bone regeneration has been studied extensively, but successful translation to the clinic has been slow. Significantly less attention has been given to porosity at the microscale (0.5-10 microm). While some have shown that microporosity in calcium phosphate (CaP)-based scaffolds can improve rate and extent of bone formation in macropores, none has explored microporosity as an additional and important space for bone ingrowth. Here we show osteointegration of biphasic calcium phosphate (BCP) scaffolds at both the macro and micro length scales. Bone, osteoid, and osteogenic cells fill micropores in scaffold rods and osteocytes are embedded in mineralized matrix in micropores, without the addition of growth factors. This work further highlights the importance of considering design parameters at the microscale and demonstrates the possibility for a bone-scaffold composite with no "dead space." Embedded osteocytes distributed throughout microporous rods may form a mechanosensory network, which would not be possible in scaffolds without microporosity. Multiscale osteointegration has the potential to greatly improve overall performance of these scaffolds through an improvement of mechanical properties, load transfer, and stability in the long and short term, and represents a new paradigm for scaffold design.
Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 West Green Street, Urbana, IL 61801, USA.
Sheeny K
SK
Lan Levengood
Samantha J
SJ
Polak
Matthew B
MB
Wheeler
Aaron J
AJ
Maki
Sherrie G
SG
Clark
Russell D
RD
Jamison
Amy J
AJ
Wagoner Johnson
D000818:Animals; D001672:Biocompatible Materials; D001861:Bone Regeneration; D002130:Calcium Phosphates; D008297:Male; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D013552:Swine; D014961:X-Ray Diffraction
D001672:Biocompatible Materials; D002130:Calcium Phosphates; C020243:calcium phosphate