Microfluidic Fabrication of Physically Assembled Nanogels and Micrometric Fibers by Using a Hyaluronic Acid Derivative

The employ of a hyaluronic acid (HA) derivative, bearing octadecyl (C18) and ethylenediamine (EDA) groups, for microfluidic fabrication of nanogels and microfibers is reported in this study. Two HA-EDA-C18 derivatives (125 and 320 kDa) having ionic strength sensitive properties are synthesized and characterized. The control of the rheological properties of HA-EDA-C18 aqueous dispersions by formation of inclusion complexes with hydroxypropyl-beta-cyclodextrins (HPCD) is described. Reversibility of C18/HPCD complexation and physical crosslinking is detected in media with different ionic strength through oscillation frequency tests. HA-EDA-C18 125 kDa is employed for nanogel fabrication. Control over nanogel dimension by flow ratio regulation is demonstrated. HA-EDA-C18 320 kDa with HPCD is employed for fabrication of both microfibers and microchannels. Dimension of fibers is controlled by modulating flow ratios. Suitability for biological functionalization is assayed introducing cell adhesive peptides. Adhesion and encapsulation of human umbilical vein endothelial cells is evaluated.