A novel 3D bone-mimetic scaffold composed of collagen/MTA/MWCNT modulates cell migration and osteogenesis

Abstract

AimsThis study characterized a three-dimensional (3D) biocomposite scaffolds produced using type I collagen, mineral trioxide aggregate (MTA) and multi-walled carbon nanotubes (MWCNT) to be used in bone tissue regeneration. Main methodsThe scaffolds were analyzed via scanning (SEM) and transmission (TEM) electron microscopy, as well as the viability and migration of osteoblasts and mineralization of the scaffolds. Key findingsSEM and TEM analyses showed that MTA and MWCNT were distributed as both large agglomerates entrapped within the collagen network and as smaller accumulations or individual molecules dispersed throughout the scaffold. Ultrastructural analysis revealed that osteoblastic MC3T3-E1 cells grown in the biocomposite endocytosed MWCNT, which were localized in the cytoplasm and in vesicles. Analysis of cells grown in the 3D scaffolds demonstrated that >95% of the cells remained viable in all tested combinations and concentrations of the biocomposite. MC3T3-E1 osteoblasts migrated into scaffolds formed with concentrations of type I collagen between 1.75 and 3.0mg/mL. Cells displayed increased migration into scaffolds formed with collagen and a range of low to high concentrations of MTA. In contrast, the presence of MWCNT in the biocomposite had a slight negative effect on migration. Collagen gels containing specific concentrations of MTA, or MWCNT, or combinations of MTA/MWCNT, caused an increase in mineralization of scaffolds. SignificanceScaffolds composed of defined concentrations of type I collagen, MTA and MWCNT are biocompatible, promote migration and mineralization of osteoblasts, and hence may be useful as bone tissue mimetics.