3D Printed Multilayered Scaffold with an ECM Hydrgel Coating Cartilage Layer Enhances Osteochondral Defect Repair报告人:
Shenzhen Institutes of Advanced Technology
Cairong Li is currently an assistant researcher of biomaterials in the Centre for Translational Medicine Research & Development at Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences and is studying for her PhD at the University of Chinese Academy of Sciences. She completed undergraduate degrees in Material forming and control engineering at Shaanxi University of Science and Technology. While completing her Masters degree in Materials science and engineering at Jinan University, her research focused on preparation and application of nanocomposites. Her current research interest is development of bioactive orthopedic biomaterials. She has received numerous awards, including a Director Innovation Fund Academic Achievement Award (2020) and Outstanding Employee Award (2020) from Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences.
Osteochondral defects are most commonly characterized by damages to both cartilage and bone tissues as a result of serious traumas or physical diseases, because these two tissues have their own unique biological properties, developing a single monophasic scaffold that can concurrently regenerate these two specific lineages becomes a challenge. One promising strategy to reconstruct osteochondral defects relies on 3D printed multilayered structures comprised of hyaline cartilage and subchondral bone. In this study, we designed and fabricated a 3D-printed polycaprolactone (PCL) composite bilayer scaffold composed of extracellular matrix (ECM)/PCL layer and polydopamine-coated magnesium oxide nanoparticles (MD)/PCL subchondral bone-like layer by low-temperature 3D printing technology. Then, the ECM/PLC layer was imersed in ECM solution at 37 ℃ for 1 h, a layer of ECM hydrogel stably adhere to the surface of the ECM/PCL scaffolds as cartilage-like layer and coded as co-ECM/PCL. The multilayered structure enable the scaffold to mimic the natural osteochondral structure (figure 1 (a)) and its physical structuer, mechanical properties and degradation properties were characterized (figure 1 (b)). In addition, the MD/PCL could enhance the osteoblast differentiation of BMSCs by upregulating their alkaline phosphatase and collagen I gene expressions, and the ECM/PCL coated with ECM hydrogel could promote the chondrocyte differentiation of BMSCs by upregulating their Acan and collagen II gene expressions, which indicated that this stratified scaffold could mimic the natural osteochondral function (figure 1 (c)). Furthermore, after the stratified construct was implanted into a rat osteochondral defect model, obvious neonatal articular cartilage tissues and subchondral bone tissues with regular surface and highly integration with normal tissues could be observed (figure 1 (d)). This structural and functional biomimetic construct, together with its proper mechanical properties and degradation properties, could not only stimulate the hyaline cartilage and subchondral bone regeneration in an entire osteochondral unit but also promote the integration between the newly formed tissues and the host tissue.
Figure 1. Abstract graphic of 3D printed multilayered scaffold with an ECM Hydrgel coating cartilage layer enhances osteochondral defect repair