A three dimensional meniscal scaffold with controlled fibre diameter and orientation was fabricated by an improved E-Jetting system that mimic the internal structure of natural meniscus. In vitro cellular tests proved its feasibility in meniscal tissue engineering applications. Current surgical and repair methods for complex meniscal injuries still do not often give satisfactory long-term results. Thus, scaffold-based grafts are the subject of much research interest. However, one major hurdle is that current techniques are unable to replicate the precise 3D microstructure of meniscus, nor the variations in the fibrillar structure and tissue content from layer to layer. In this work, an improved electrohydrodynamic jet printing system (E-Jetting system) was developed to fabricate biomimetic meniscal scaffold for tissue regeneration.Summary Statement
Introduction
Fracture healing represents a physiological process regulated by a variety of signalling molecules, growth factors and osteogenic progenitor cells. Bone healing following trauma is associated with increased serum concentrations of several pro-inflammatory and angiogenic growth factors1. Platelet-derived growth factor (PDGF) has been shown to stimulate mesenchymal stem cell (MSC) proliferation in vitro. However, the in vivo relationship between the levels of PDGF and the numbers of MSCs in humans has not yet been explored. The aim of this study was to investigate PDGF release in the peripheral circulation following trauma and to correlate it with the numbers of MSCs in iliac crest bone marrow (BM) aspirate and in peripheral blood. Trauma patients with lower extremity fractures (n=12, age 18-63 years) were recruited prospectively. Peripheral blood was obtained on admission, and at 1, 3, 5 and 7 days following admission. The serum was collected and PDGF was measured using the enzyme-linked immuno-sorbent assay (ELISA) technique. Iliac crest (BM) aspirate (20ml) and peripheral blood (PB) (20ml) was obtained on days 0-9 following admission. MSCs were enumerated using standard colony-forming unit fibroblasts (CFU-F) assay.Background and objectives
Methods