1. Electrospinning

The primary objective in tissue-engineered scaffold design is to create materials that mimic the structure and function of the native extracellular matrix (ECM). The ECM is a complex network of proteins, proteoglycans, and glycosaminoglycans that provides physical support for cells. It also plays a crucial role in promoting cell adhesion, migration, proliferation, and function, partly due to the intricate nanostructure of protein fibers like collagen and elastin, along with specific ligands and growth factors. Electrospun fibrous scaffolds have found widespread use in tissue engineering and biomedical applications due to their ability to encourage favorable cellular responses, including enhanced adhesion and proliferation. In our lab, we aim to develop fibrous scaffolds with fiber diameters ranging from tens to hundreds of nanometers to closely mimic the native ECM. These scaffolds have been applied in various tissue engineering applications, such as synthetic blood vessels, fibrous cardiopatches, and urethral patches, boasting exceptional mechanical properties, high biodegradability, and biocompatibility. When it comes to urethral tissue engineering, the ideal graft should replicate the structural and functional properties of native urethral tissue. This includes promoting biocompatibility for cell adhesion, providing a highly permeable 3D fiber structure that mimics the ECM to facilitate cell migration and cell-cell adhesion, ensuring a protective barrier against urine. The engineered graft should also support vascularization, withstand surgical forces, and closely resemble the native urethra both in structure and function. In our ongoing collaborative projects with a urological surgeon, we have designed highly elastic, biomimetic fibrous patches incorporating elastin-like polypeptides (ELPs) for lower urinary tract reconstruction. ELPs are included to create suturable, highly elastic scaffolds with controlled degradation and swelling while electrospinning technique is employed to control scaffold nanotopography and contribute to scaffold elasticity.

Lab members working in this area: Ronak Afshari, Zijian Zhong

2. 3D Bioprinting

3D bioprinting is an innovative technique in tissue engineering, allowing for the creation of complex, multi-layered 3D structures that are often challenging to produce using traditional methods like molding or milling. This technology is particularly valuable for replicating cell-laden structures that closely resemble various tissues. This technology has shown tremendous potential to overcome issues with organ transplant shortages, facilitating drug testing and screening, and advancing the study of biological phenomena such as tissue morphogenesis. In our laboratory, we utilize a CellINK and Allevi 3D printer equipped with dual printheads to replicate the complexity of native tissues as they exist in vivo. Our main focus centers on engineering elastic bioinks and constructing diverse scaffold shapes through 3D bioprinting. This enables us to mimic the mechanical properties (e.g., softness, stretchability, and elasticity) and intricate microarchitecture of human tissues like skin, lung, skeletal muscle, and cardiovascular tissues. Our ongoing project aims to synthesize personalized multi-layered cell-laden tubular structures that closely mimic the native structure of the urethra, offering innovative solutions for various urethral diseases. Additionally, we are working on the design of artificial vagina structures using 3D bioprinting, incorporating antibacterial drugs for enhanced functionality.

Lab members working in this area: Ronak Afshari, Arpita Roy, Zijian Zhong, Steven Vo

  • Booth, D., Afshari, R., Ghovvati, M., Shariati, K., Sturm, R., Annabi, N., 2023. Advances in 3D Bioprinting for Urethral Tissue Reconstruction. Trends in biotechnology, Accepted.
  • Davoodi, E., Montazerian, H., Zhianmanesh, M., Abbasgholizadeh, R., Haghniaz, R., Baidya, A., Pourmohammadali, H., Annabi, N., Weiss, P.S., Toyserkani, E. and Khademhosseini, A., 2022. Template‐enabled biofabrication of thick 3D tissues with patterned perfusable macrochannels. Advanced Healthcare Materials, 11(7), p.2102123.
  • Zandi, N., Sani, E.S., Mostafavi, E., Ibrahim, D.M., Saleh, B., Shokrgozar, M.A., Tamjid, E., Weiss, P.S., Simchi, A. and Annabi, N., 2021. Nanoengineered shear-thinning and bioprintable hydrogel as a versatile platform for biomedical applications. Biomaterials, 267, p.120476.
  • Lee, S., Sani, E.S., Spencer, A.R., Guan, Y., Weiss, A.S. and Annabi, N., 2020. Human‐recombinant‐Elastin‐based bioinks for 3D bioprinting of vascularized soft tissues. Advanced Materials, 32(45), p.2003915.
  • Spencer, A.R., Shirzaei Sani, E., Soucy, J.R., Corbet, C.C., Primbetova, A., Koppes, R.A. and Annabi, N., 2019. Bioprinting of a cell-laden conductive hydrogel composite. ACS Applied Materials & Interfaces, 11(34), pp.30518-30533.
  • Portillo-Lara, R., Spencer, A.R., Walker, B.W., Sani, E.S. and Annabi, N., 2019. Biomimetic cardiovascular platforms for in vitro disease modeling and therapeutic validation. Biomaterials, 198, pp.78-94.
  • 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)