Multicomponent hydrogel fibers for tendon tissue engineering: combining polyelectrolyte complexation and microfluidics

Tendons are responsible for force transmission between muscles and bones, assuring body movement. Given the poor healing capacity of tendons, tissue engineering strategies have been focused on translating tendon architecture and functionality into biomimetic materials. In the present study, multicomponent hydrogel fibers were fabricated by combining microfluidics with polyelectrolyte interactions. For this, methacrylated hyaluronic acid (MA-HA) and chondroitin sulfate (MA-CS) were combined with chitosan (CHT). Hydrogel fibers were obtained as a result of material interactions upon contact at the interface inside the common channel and by further photocrosslinking MA-HA and MA-CS. Biological perfomance was studied by encapsulating human tendon derived cells (TDCs), which were homogeneously distributed along the fibers and were viable after 7 days in culture. Also, TDCs were able to produce collagen type 1 and tenascin, which are extracellular matrix components found in native tendons. The combination of microfluidics with both physical and chemical crosslinking mechanisms allowed the fabrication of multicomponent hydrogel fibers mimicking tendon composition and a matrix-rich environment.