Endocultivation: 3D printed customized porous scaffolds for heterotopic bone induction.
The aim of this study was to evaluate the ability of computer assisted designed (CAD) synthetic hydroxyapatite and tricalciumphosphate blocks to serve as precise scaffolds for intramuscular bone induction in a rat model. A central channel to allow for vessel pedicle or nerve integration was added. Natural bovine hydroxyapatite blocks served as controls to evaluate and compare biocompatibility of the new matrices. Individually designed 3D-printed rounded and porous hydroxyapatite (HA) and tricalcium phosphate (TCP) blocks were placed in pouches in the Musculus latissimus dorsi in 12 Lewis rats bilaterally. Bovine hydroxyapatite blocks with and without a central channel served as controls. Simultaneously, 200 microg rhBMP-2 in 1 ml sodium chloride was injected on both sides. For 8 weeks, bone generation was monitored by computer tomography and fluorescence labeling. The increase rates of bone density in CT examinations were higher in the HA groups (184-220 HU 8 weeks after implantation) compared to the TCP group (18 HU; p<0.0001). Microradiography and fluorescence microscopy 8 weeks after implantation showed new bone formation for all materials tested. For all scaffolds, toluidine staining revealed vital bone directly on the scaffold materials but also in the gaps between. It can be concluded from our data that the specially shaped hydroxyapatite and tricalcium phosphate blocks tested against the bovine hydroxyapatite blocks showed good biocompatibility and osteoinductivity in vivo. Further studies should explore if the stability of the individually designed blocks is sufficient to cultivate larger replacements without an external matrix for support.
Becker
Stephan T
ST
Department of Oral and Maxillofacial Surgery, Christian-Albrechts-University Kiel, Germany. becker@mkg.uni-kiel.de
Bolte
Hendrik
H
Krapf
Oliver
O
Seitz
Hermann
H
Douglas
Timothy
T
Sivananthan
Sureshan
S
Wiltfang
Jörg
J
Sherry
Eugene
E
Warnke
Patrick H
PH
D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use*; D015519:Bone Density; D018786:Bone Substitutes / Q000592:standards*; D002130:Calcium Phosphates / Q000627:therapeutic use*; D002417:Cattle; D017076:Computer-Aided Design; D004195:Disease Models, Animal; D017886:Durapatite / Q000627:therapeutic use*; D008852:Microradiography; D008856:Microscopy, Fluorescence; D010012:Osteogenesis; D051381:Rats; D011917:Rats, Inbred Lew; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000592:standards*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; D017886:Durapatite; C018392:tricalcium phosphate