Keratinocytes HaCat proliferation on 3D-printed collagen-chitosan scaffolds

PEREZ RECALDE MERCEDES; JULIETA POLENTA; ANA GONZALEZ WUSENER; ALBERTO BOLGIANI; ELIDA B. HERMIDA

Dresden

Congreso; 6th Cellular Materials (CellMat 2020); 2020

DGM: German Materials Society

KERATINOCYTES HaCaT PROLIFERATION  ON 3D-PRINTEDCHITOSAN-COLLAGEN SCAFFOLDS Despite the wide advances in biomaterials for tissueengineering, autografts are today the only artifact to promote epidermisregeneration in chronic wounds and in acute wounds greater than 4 cm indiameter. This feature remarks the importance of autologous epidermal cells inthe healing process, thus the importance of developing biomaterials for seedingthese cells. Hydrogels have largely proved to be suitable for cellsproliferation, and 3D bioprinting has become an innovative technique forsetting biomaterials and cells according to a controlled digital design. Weaimed to inquire in the collagen (Col)) and chitosan (Chit) blends to this typeof application. Two printable hydrogel precursors were selected, in %w/v, Chit 1.00:Col 0.36 and Chit 0.50:Col 0.54, both at pH=4.50 because of thepolymer solubilities. They were analyzed rheologically, particularly consideringthe strain rate of a 3D-bioprinter (30-60 1/s) prototype made in Argentina: viscositiesduring the extrusion were in the interval 0.5-0.8 Pa.s. In order to make theinks suitable for cell life, a method for misting NaHCO3 0.8 M wasdeveloped, obtaining pH ~ 6 homogenous inks storable during 5 days with no importantchanges in stability, viscosity and printing fidelity, when compared to theirnon-misted counterparts. To generate a post-printed scaffold, activators EDC/NHS were added in solid form immediately before printing, to give crosslinkedmanipulable substrates, that were no cytotoxic according to the ISO rule 10993-5using NH-3T3 fibroblasts. For advancing to scarfskin regeneration, keratinocytesproliferation was tested by seeding 105 HaCat cells/well, in a24-wells plate with hydrogels printed in each well. Cells showed excellentadhesion and capability to proliferate on the hydrogels after 5 days in bothscaffolds. Window time available for printing without gelation remains to bedefined, as well as scaffold swelling and stability, both features partially dimmableby crosslinkers concentration.