Biomineralized hydroxyapatite nanoclay composite scaffolds with polycaprolactone for stem cell‐based bone tissue engineering

• Published in: Journal of biomedical materials research. Part A Vol. 103; no. 6; pp. 2077 - 2101
• Main Authors: Ambre, Avinash H., Katti, Dinesh R., Katti, Kalpana S.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.06.2015
• Subjects: Alkaline Phosphatase - metabolism; Aluminum Silicates - pharmacology; Biomedical materials; biomineralization; Bone and Bones - drug effects; Bone and Bones - physiology; bone tissue engineering; Bones; Calcification, Physiologic - drug effects; Cell Differentiation - drug effects; Cell Survival - drug effects; Cells, Cultured; Compressive Strength - drug effects; Durapatite - pharmacology; Electrochemical machining; Extracellular Matrix - drug effects; Extracellular Matrix - metabolism; Humans; hydroxyapatite composite; Imaging; mesenchymal stem cell; Mesenchymal Stromal Cells - cytology; Mesenchymal Stromal Cells - drug effects; Mesenchymal Stromal Cells - ultrastructure; nanoclay; Nanoparticles - chemistry; Nanoparticles - ultrastructure; Nanostructure; Particulate composites; Polyesters - pharmacology; Porosity; Scaffolds; Spectroscopy, Fourier Transform Infrared; Staining and Labeling; Surgical implants; Tissue Engineering - methods; Tissue Scaffolds - chemistry; nanoclay; mesenchymal stem cell; biomineralization; hydroxyapatite composite; bone tissue engineering
• ISSN: 1549-3296; 1552-4965
• DOI: 10.1002/jbm.a.35342

Nanoclay modified with unnatural amino acid was used to design a nanoclay‐hydroxyapatite (HAP) hybrid by mineralizing HAP in the nanoclay galleries mimicking biomineralization. This hybrid (in situ HAPclay) was used to fabricate polycaprolactone (PCL)/in situ HAPclay films and scaffolds for bone regeneration. Cell culture assays and imaging were used to study interactions between human mesenchymal stem cells (hMSCs) and PCL/in situ HAPclay composites (films and scaffolds). SEM imaging indicated MSC attachment, formation of mineralized extracellular (ECM) on PCL/in situ HAPclay films, and infiltration of MSCs to the interior of PCL/in situ HAPclay scaffolds. Mineralized ECM was formed by MSCs without use of osteogenic supplements. AFM imaging performed on this in vitro generated mineralized ECM on PCL/in situ HAPclay films revealed presence of components (collagen and mineral) of hierarchical organization reminiscent of natural bone. Cellular events observed during two‐stage seeding experiments on PCL/in situ HAPclay films indicated similarities with events occurring during in vivo bone formation. PCL/in situ HAPclay films showed significantly increased (100–595% increase in elastic moduli) nanomechanical properties and PCL/in situ HAPclay scaffolds showed increased degradation. This work puts forth PCL/in situ HAPclay composites as viable biomaterials for bone tissue engineering. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 2077–2101, 2015.