The meniscus is a fibrocartilage tissue that is integral
to the
correct functioning of the knee joint. The tissue possesses a unique
collagen fiber architecture that is integral to its biomechanical
functionality. In particular, a network of circumferentially aligned
collagen fibers function to bear the high tensile forces generated
in the tissue during normal daily activities. The limited regenerative
capacity of the meniscus has motivated increased interest in meniscus
tissue engineering; however, thein vitrogeneration
of structurally organized meniscal grafts with a collagen architecture
mimetic of the native meniscus remains a significant challenge. Here
we used melt electrowriting (MEW) to produce scaffolds with defined
pore architectures to impose physical boundaries upon cell growth
and extracellular matrix production. This enabled the bioprinting
of anisotropic tissues with collagen fibers preferentially oriented
parallel to the long axis of the scaffold pores. Furthermore, temporally
removing glycosaminoglycans (sGAGs) during the early stages ofin vitrotissue development using chondroitinase ABC (cABC)
was found to positively impact collagen network maturation. Specially
we found that temporal depletion of sGAGs is associated with an increase
in collagen fiber diameter without any detrimental effect on the development
of a meniscal tissue phenotype or subsequent extracellular matrix
production. Moreover, temporal cABC treatment supported the development
of engineered tissues with superior tensile mechanical properties
compared to empty MEW scaffolds. These findings demonstrate the benefit
of temporal enzymatic treatments when engineering structurally anisotropic
tissues using emerging biofabrication technologies such as MEW and
inkjet bioprinting.