The renaissance of one-dimensional carbon nanotubes in tissue engineering

The severe imbalance between supply and demand has remained a life-threatening situation for patients undergoing organ resection or severe tissue damage. To resolve this, numerous nanomaterials have been exploited toward biological tissue engineering to assist tissue regeneration and even create artificial organs in vitro. Among these, carbon nanotubes (CNTs) have emerged as promising platforms by virtue of their unique mechanical, electrical, thermal, antibacterial, and modifiable properties. CNTs are usually used as additives in common biological or abiotic tissue engineering scaffolds to modify the structure, porosity, mechanical strength, electrical conductivity, thermal conductivity, degradation rate, and biocompatibility on the order of microns. Importantly, the modifiability of CNTs enables many possible configurations for tissue engineering, e.g., adding functional groups or molecules to regulate the development process and cellular microenvironment. This review summarizes applications and design strategies of CNTs in bone, cardiac, vascular, nerve, and other tissue engineering fields. In addition, we discuss the possible biosafety risks of CNTs and corresponding solutions. Finally, we speculate on the future developments of CNTs in tissue engineering.