MicroCT analysis of hydroxyapatite bone repair scaffolds created via three-dimensional printing for evaluating the effects of scaffold architecture on bone ingrowth.
Recent studies have shown that it is now possible to construct tissue-engineered bone repair scaffolds with tight pore size distributions and controlled geometries using 3-D Printing techniques (3DP). This study evaluated two hydroxyapatite (HA) 8-mm diameter discs with controlled architectures in a rabbit trephine defect at 8 and 16 weeks using a 2 x 2 factorial design. Input parameters were time and scaffold void volume at two levels. Three output variables were extracted from MicroCT data: bone volume ingrowth with respect to total region of interest, bone volume ingrowth with respect to available ingrowth volume, and soft tissue volume. The experiment measured two groups--Group 1: 500-microm x 500-microm channels parallel to the scaffold's long axis and penetrating up 3-mm from the bottom. Group 2: 800-microm x 800-microm struts spaced 500 microm apart set perpendicularly to each other in each printed layer. Rendered 3-dimensional MicroCT scans and undecalcified histological slides of implants revealed good integration with the surrounding tissue, and a sizeable amount of bone ingrowth into the device. Factorial analysis revealed that the effects of time were the greatest determinant of soft tissue ingrowth, while time and its interaction with void volume were the greatest determinants of bone volume ingrowth with respect to both total and available volume.
Simon
Joshua L
JL
Department of Orthopedics, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103-2714, USA. joshua.simon@ebimed.com
Rekow
E Dianne
ED
Thompson
Van P
VP
Beam
Heather
H
Ricci
John L
JL
Parsons
J Russell
JR
D000818:Animals; D001846:Bone Development; D018786:Bone Substitutes; D017886:Durapatite; D008422:Materials Testing; D011817:Rabbits; D023822:Tissue Engineering; D014057:Tomography, X-Ray Computed
D018786:Bone Substitutes; D017886:Durapatite