Evaluation of multi-scale mineralized collagen-polycaprolactone composites for bone tissue engineering.
A particular challenge in biomaterial development for treating orthopedic injuries stems from the need to balance bioactive design criteria with the mechanical and geometric constraints governed by the physiological wound environment. Such trade-offs are of particular importance in large craniofacial bone defects which arise from both acute trauma and chronic conditions. Ongoing efforts in our laboratory have demonstrated a mineralized collagen biomaterial that can promote human mesenchymal stem cell osteogenesis in the absence of osteogenic media but that possesses suboptimal mechanical properties in regards to use in loaded wound sites. Here we demonstrate a multi-scale composite consisting of a highly bioactive mineralized collagen-glycosaminoglycan scaffold with micron-scale porosity and a polycaprolactone support frame (PCL) with millimeter-scale porosity. Fabrication of the composite was performed by impregnating the PCL support frame with the mineral scaffold precursor suspension prior to lyophilization. Here we evaluate the mechanical properties, permeability, and bioactivity of the resulting composite. Results indicated that the PCL support frame dominates the bulk mechanical response of the composite resulting in a 6000-fold increase in modulus compared to the mineral scaffold alone. Similarly, the incorporation of the mineral scaffold matrix into the composite resulted in a higher specific surface area compared to the PCL frame alone. The increased specific surface area in the collagen-PCL composite promoted increased initial attachment of porcine adipose derived stem cells versus the PCL construct.
Department of Material Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
D W
DW
Weisgerber
Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
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K
Erning
Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States.
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CL
Flanagan
Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States; Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, United States.
S J
SJ
Hollister
Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States. Electronic address: bharley@illinois.edu.
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BAC
Harley
D000273:Adipose Tissue / Q000166:cytology; D000818:Animals; D001696:Biomechanical Phenomena; D001842:Bone and Bones / Q000502:physiology*; D003094:Collagen / Q000737:chemistry*; D006801:Humans; D010012:Osteogenesis; D011091:Polyesters / Q000737:chemistry*; D013234:Stem Cells / Q000166:cytology; D013552:Swine; D023822:Tissue Engineering; D054457:Tissue Scaffolds
D011091:Polyesters; C016240:polycaprolactone; D003094:Collagen
Biomaterial; Bone; Collagen; Craniofacial; Multi-scale; Polycaprolactone