Professor Jiandong Ding
Fudan University, China
A Study of Structural Mechanics of 3D-printed Polymeric Scaffolds
Abstract: While various studies have been reported about fabrication of porous scaffolds and corresponding efficacies of tissue engineering and regeneration, relatively few studies are focused on structural mechanics of porous scaffolds which is ready for 3D printing. This lecture will report our recent preliminary research of polyester scaffolds. We designed three arrays available for 3D printing. Tetragonal, hexagonal and wheel-like porous scaffolds were fabricated via fused deposition modelling (FDM), and also modelled by finite element analysis. The three arrays with similar porosity were successfully fabricated as shown in Figure 1, and. Their mechanical properties including fatigue behaviours were measured and compared. All of the three examined arrays are reasonable for tissue engineering scaffolds. Even under a similar porosity, structure can influence the resultant scaffold mechanics.
Biography: Prof. Jiandong DING is the director of The State Key Laboratory of Molecular Engineeirng of Polymers, and distinguished professor at Department of Macromolecular Science, Fudan University. He obtianed his BS from School of Life Sciences in 1988, MS from Department of Materials Science in 1991, PhD from Department of Macromolecule Science in 1995 at the same university, Fudan University. He did his postdoctor research in Department of Materials Science, University of Cambridge. He is leading a biomaterials group covering biodegradable polymers, release carriers of drugs, and regenerative medicine. He was awarded as First-rate Prize of Natural Science Research by Ministry of Education. He is a Chang-Jiang Scholar selected by Ministry of Education and a Distinguished Young Scientist by Natural Science Foundation. He was a chief scientist of a 973 program from Ministry of Science and Technology, and is currently leading a National Key R&D Program of China about biomedical materials.
Dr. Ding is a fellow of International Union of Societies of Biomaterials Science and Engineering. He serves as a member or advisory member of Editorial Board of some international academic journals such as Regenerative Biomaterials, Macromolecules, ACS Biomaterials Science and Engineering, Bio-design and Manufacturing.
Professor Zhongze Gu
Southeast University, China
Organs-on-Chips based on Multi-Scale Two-Photon Polymerization
Abstract: Organs-on-chips systems are physiological platforms that reconstitute the critical features of human organs and the interactions between different tissues. They bring benefits to a diversity of applications, including drug discovery, toxicity testing, and disease modeling. To mimic living organs and tissues faithfully, microfluidic channels and 3D scaffolds are integrated into one system for cell culture in vitro and viability monitoring in situ. However, current fabrication technologies cannot satisfy complex geometrical configurations as well as the feature sizes from micrometer to nanometer.As an emerging additive manufacturing technology, two-photon polymerization (TPP) has shown the enormous potential of being a general fabrication method for complex microstructures due to its unique advantage in direct laser writing of 3D architectures with high resolution. For organ-on-chips systems, traditional TPP needs improvements in the working range up to the centimeter scale and biocompatible materials. Here, we developed a multi-scale TPP platform with advanced optical setup, a processing algorithm, and the hydrogel materials. Considering the resolution of different regions in an organ-on-a-chip, the feature size of TPP could be tuned from 100 nm to 10 μm by the numerical aperture of the objective, the laser power, and the scanning speed. A processing algorithm for optimal scanning path is applied to control the translation stages with different displacement ranges of 300 μm and 26 mm. Moreover, some biocompatible hydrogel materials have demonstrated the ability for TPP and their physical properties could be tuned to obtain different stiffness and stimuli response, which opens a new avenue for cell scaffolds and biosensors.
Biography: Zhongze Gu is currently the professor and the dean of School of Biological Science and Medical Engineering of Southeast University, the director of JITRI Institute of Biomaterials and Biomedical Devices. He is also the council member of the Chinese Society of Biomaterials, the Chinese Society of Biomedical Engineering, and the Chinese Society for Cognitive Science. He graduated from Southeast University (China) in 1989 and got his M.S. in 1992 there. He received his Ph.D. degree in 1998 from the University of Tokyo (Japan). From 2003, he has been a Cheung Kong Scholars Professor at Southeast University. His research interests include bio-inspired intelligent materials, colloidal crystals, and organ-on-a-chip. He is now a leader of a National Key R&D Program of China, which is responsible for promoting the development of Organ-on-a-chip in China.
Professor Zhiwu Han
Abstract: Sensors which regarded as the basis of intelligent manufacturing are the source of information acquisition. Among various types of sensors, mechanosensors can convert mechanical signals including sound, pressure, vibration, air/water flow, etc. into electrical responses. However, development of mechanosensors with excellent comprehensive performance (ultrasensitive, micro/nanoscale, anti-interference, low-power, low hysteresis, etc.) has always been a great challenge. Fortunately, animals have evolved sophisticated mechanosensors with excellent comprehensive performance to survive in the cruel natural environment. The visual system of scorpions has highly degraded and they rely heavily on the slit-based mechanosensors to accurately detect nanoscale amplitude vibration signals from noise environment. Hence, the scorpions provide broad bioinspired strategies for designing new generation mechanosensors. In this work, the compositions of functional units, structural characteristics, material compositions, mechanical properties as well as the coupling sites between mechanosensory neuron and slit units of scorpion Heterometrus petersii were thoroughly investigated. The experimental results and theory analysis indicate that the slit-based mechanoreceptor can effectively collect the tiny mechanical signals through utilizing the near-tip stress field of slit, and then convert the mechanical signals into electrical responses through mechanosensory neuron. Meanwhile, two bionic models of mechanosensors based on the structural characteristics and functional mechanism were established, respectively. The results indicate the scorpion-inspired mechanosensors based on the two bionic models can possess comprehensive high-performance.
Biography: Prof. Zhiwu Han is the Dean of Key Laboratory of Bionic Engineering of Ministry of Education (KLBE), Jilin University. He was selected as the Changjiang Scholar, and the Distinguished Young Scholar of NSFC. He was also the Senior Visiting Scholar at Oxford University in the UK, the State Representative of International Society of Bionic Engineering (ISBE), and the ISBE Fellow. His research interests include machinery biomimetics, biomimetic functional surfaces, bioinspired sensors, and bionic technologies applied in engineering, etc. In the past decades, he has published more than 100 SCI articles in high-level journals，such as Nature, Advanced Materials, Advanced Functional Materials, ACS Nano, Small, ACS AMI, Nanoscale, Langmiur, APL, etc.