Enhanced Mechanical and Cytocompatibility Properties of Novel 3D Printed Osteochondral Scaffolds

B. Holmes, LG. Zhang
The George Washington University, US

Keywords: scaffold, stem cell, osteochondral, 3D printing, nanomaterial

Summary:

A series of novel 3D osteochondral computer aided models were designed including a homogenous cross-hatched structure, a bi-phasic structure consisting of a cross hatched pattern and an intersecting rings structure, and a biphasic “key” model (Figure 1). Our mechanical testing results showed that the novel designed biphasic osteochondral structures have enhanced mechanical characteristics in compression and sheer (Figure 2) when compared to traditional designs. In order to improve scaffolds’ biocompatibility, two additional sample groups were also coated in acetylated collagen and poly-l-lysine coated multi-walled carbon nanotubes (MWCNTs).The proliferation study showed an increase on all samples on day one, with greater cellular activity on bi-phasic scaffolds when compared to control groups in vitro. Furthermore, the scaffolds with acetylated collagen and MWCNTs outperformed all other groups, which show that these nano surface modifications can further increase MSC growth. MSC chondrogenic differentiation results showed enhanced glycosaminoglycan, collagen type II and total protein synthesis (Figures 3 and 4) on bi-phasic key and collagen coated scaffolds after two weeks of culture.