Micro- and nano-formulations for bioprinting and additive manufacturing.

Recent developments in bioprinting have enabled an optimized formulation of bioinks by incorporating pharmaceuticals into cell-containing gel matrices. The proof-of-printability of a variety of forms has been provided, such as particles and fibers in the nanometric or micrometric range like dendrimers or micelles, although this is still lacking for some (liposomes for example). Resulting composite bioinks have the advantage of (i) improving cell growth and differentiation, (ii) delivering active molecules or (iii) improving mechanical properties of bioinks, printed scaffolds or the printing process. Improvement of these properties brings bioprinting one step forward toward clinical applications. Applications are reviewed for each field of improvements.