Engineering natural based nanocomposite inks via interface interaction for extrusion 3D printing.

[Display omitted] • A versatile methodology for the improvement of the interaction between composing phases of a nanocomposite (light-responsive protein and aminated nanoparticles) is thoroughly described. • The interfacial interaction was conducted by EDC and NHS carbodiimide chemistry. • The improved interface interactions effectively immobilize the BGNP, showing increased elastic and viscous modulus comparing with controls. • This chemistry allowed tunning low viscous heterogenous materials into appropriate inks for extrusion 3D printing. • This system can further reproducibly recapitulate phases of other natures, broadening applicability. Nanocomposites and low-viscous materials lack translation in additive manufacturing technologies due to deficiency in rheological requirements and heterogeneity of their preparation. This work proposes the chemical crosslinking between composing phases as a universal approach for mitigating such issues. The model system is composed of amine-functionalized bioactive glass nanoparticles (BGNP) and light-responsive methacrylated bovine serum albumin (BSAMA) which further allows post-print photocrosslinking. The interfacial interaction was conducted by 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide crosslinking agent and N-Hydroxysuccinimide between BGNP-grafted amines and BSAMA's carboxylic groups. Different chemical crosslinking amounts and percentages of BGNP in the nanocomposites were tested. The improved interface interactions increased the elastic and viscous modulus of all formulations. More pronounced increases were found with the highest crosslinking agent amounts (4 % w/v) and BGNP concentrations (10 % w/w). This formulation also displayed the highest Young's modulus of the double-crosslinked construct. All composite formulations could effectively immobilize the BGNP and turn an extremely low viscous material into an appropriate inks for 3d printing technologies, attesting for the systems' tunability. Thus, we describe a versatile methodology which can successfully render tunable and light-responsive nanocomposite inks with homogeneously distributed bioactive fillers. This system can further reproducibly recapitulate phases of other natures, broadening applicability. [ABSTRACT FROM AUTHOR]