报告题目:

Thermally reversible hydrogels for indirect printing of skull vascular networks

报告人:

Shuxian Zheng

所在单位:

School of Mechanical Engineering, Tianjin University

Biography: 

Associate professorprofessor at School of Mchanical Enginerring, Tianjin University, supervisor for postgraduates.

The research areas are Mechanical engineering and Biomedical manufacturing cross disciplines. Undertook/participated 5 National Natural Science Funds, 1 National Key Research and Development Plan, 2 Provincial and ministerial level projects and 3 Enterprise Commission projects. The main research projects are “Study on the key technologies of intraoperative bioprinting for cranial defect repair and its regeneration mechanism”, “Additive manufacturing and vascularized study on vessel embedded compound scaffold for defect cranium”, “Research and demonstration application of key technology for robot RV reducer”. Published scientific papers more than 20 pieces in the domestic and foreign journals, and authorized 4 invention patents.

Abstract：

The construction of embedded vascular channels is the key to solving the difficulty of deep penetration of osteoblasts and the slow rate of osteogenesis for skull. However, the diploic vein of skull has the characteristics of multi-level, multi-shape, irregularly shaped thin wall, which poses a challenge to the construction process. In response to this problem, an extrusion-based indirect method was proposed to construct a multi-bionic vascular network with a certain radian of diploic veins. In this paper, kca-SF-HA/ HUVECs and kca-collagen-HA/ osteoblasts were used to construct vascular wall and lumen by sacrificing thermally reversible properties to form multi-level bifurcated cavities, and a certain spatial curvature was achieved by packed, photopolymerization and heating of PNIPAAm-PEGDA, as showed in Figure 1. Furthermore, to achieve higher printing accuracy, Firstly, rheology, mechanical properties and cytotoxicity of composite hydrogels were done to explore the thermal response characteristics, biocompatibility and printability; Secondly, a precise temperature setting window was established, and the thermal response characteristics of hydrogels and the effect of temperature-dependent printing parameters on printing accuracy were explored; Finally, printed sample with HUVECs and osteoblasts were prepared in in vitro cell-loaded bioprinting experiments to determine cell viability, adhesion, proliferation, and migration during intraluminal hydrogel sacrifice.

Figure1.  Vascular networks indirect printing (a)Process diagram of extrusion-printed vascular network, (b)A multi-level, hollow and radian vascular network wascollected at 0-6 day