Microfabrication

1. Electrospinning

The primary goal for the design of tissue engineered scaffolds is to develop materials that structurally and functionally mimics the native ECM. The ECM is a complex network of proteins, proteoglycans, and glycosaminoglycans that provides physical support for cells. Furthermore, the ECM is responsible for the promotion of cell adhesion and migration, as well as proliferation, and function. This is achieved, in part, due to the complex nanostructure of protein fibers, such as collagen and elastin, and the presence of specific ligands and growth factors. Electrospun fibrous scaffolds have been widely used in tissue engineering and biomedical applications due to the promotion of favorable cellular responses, such as increased adhesion and proliferation. In our lab, we aim to develop fibrous scaffolds with fibers diameter ranging from several tens to several hundred nanometers to closely mimic the native ECM. We have utilized these scaffolds for various tissue engineering applications such as synthetic blood vessel, and fibrous cardiopatches with high swellability, biodegradation, and high biocompatibility.

Lab members working in this area: Brian Walker

2. 3D Bioprinting

3D bioprinting is the newest trending technique in tissue engineering. 3D bioprinting technology has significantly improved over the past few decades, enabling the creation of complex 3D structures that might otherwise be impossible to fabricate with traditional molding techniques or top-down milling procedures. This technology has shown tremendous potential to overcome issues with organ transplant shortage, drug testing and screening, and the study of biological phenomena such as tissue morphogenesis. Our lab uses a pneumatic-based extrusion bioprinter with dual printheads to better represent complex tissues as they exist in vivo. Our main focus is engineering elastic bioinks that may be used with 3D printing technology to mimic the mechanical behavior (e.g. softness, stretchability, and elasticity), as well as the complex microarchitecture of native human tissues, such as skin, lung, skeletal muscle, and cardiovascular tissues.

Lab members working in this area: Sohyung Lee, Andrew Spencer

3. Wet Spinning

Wet spinning is a technique that enables rapid generation of solid fibers from a liquid prepolymer solution. The fibers are directly extruded into a liquid bath and will be further chemically crosslinked. Fibers can be easily generated with a range of diameters and properties specific to the tissue of interest. The moderate nature of this fabrication technique often enables direct encapsulation of cells within the 3D microstructure of the fibers. In our body, there are various fibrous tissues including muscle, neural, and cardiac tissues. Using wet spinning technique, we can fabricate fibrous structures that can mimic the organization of these complex tissues in the body.

Lab members working in this area: Andrew Spencer

  • Batzaya Byambaa, Nasim Annabi* , Kan Yue, Grissel Trujillo de Santiago, Mario Moisés Alvarez, Weitao Jia, Mehdi Kazemzadeh-Narbat, Su Ryon Shin, Ali Tamayol, Ali Khademhosseini*, “Bioprinted Osteogenic and Vasculogenic Patterns for Engineering 3D Bone Tissue”, Advanced Healthcare Materials, 2017, 6(16) (* Co-senior Authors) DOI: 10.1002/adhm.201700015.
  • Amir Nasajpour, Serena Mandla, Sindu Shree, Ebrahim Mostafavi, Roholah Sharifi, Akbar Khalilpour, Saghi Saghazadeh, Shabir Hassan, Michael J. Mitchell, Jeroen Leijten, Xu Hou, Alireza Moshaverinia, Nasim Annabi, Rainer Adelung,Yogendra Kumar Mishra, Su Ryon Shin, Ali Tamayol, Ali Khademhosseini, ” Nanostructured Fibrous Membranes with Rose Spike-Like Architecture”, Nano Letters201717 (10), pp 6235–6240. DOI: 10.1021/acs.nanolett.7b02929.
  • Xin Zhao, Xiaoming Sun, Lara Yildirimer, Qi Lang, Zhi Yuan William Lin, Reila Zheng, Yuguang Zhang, Wenguo Cui, Nasim Annabi, Ali Khademhosseini. “Cell infiltrative hydrogel fibrous scaffolds for accelerated wound healing,” Acta Biomaterialia, 2017, 49, 66–77 (DOI:10.1016/j.actbio.2016.11.017).
  • A. Tamayol*, A.H. Najafabadi*, N. Annabi, B. Aliakbarian, E. Arab Tehrany, A. Khademhosseini. “Hydrogel Templates for Rapid Manufacturing of Bioactive Fibers and 3D Constructs”, Advanced Healthcare Materials, 2015,vol. 4(14), pp. 2146-2153. (This paper was featured on the cover of the journal).