Characterization of the flow behavior of alginate/hydroxyapatite mixtures for tissue scaffold fabrication

Abstract

Mixtures of alginate and hydroxyapatite (HA) are promising materials for biomedical applications such as the fabrication of tissue scaffolds. In this paper, the flow behavior of alginate/HA mixtures was investigated and determined to be dependent on the concentration of both alginate and HA, and temperature. The relationships were mathematically established and verified with experimental results. As applied to the tissue scaffold fabrication, the flow rate of the biomaterial solution was predicted from the established flow behavior and verified by experiments. On this basis, the moving speed of the needle was determined and used in the tissue scaffold fabrication. The results obtained show that the knowledge of the flow behavior is essential to the fabrication of tissue scaffolds with an interconnected microstructure.

Controlled Positioning of Cells in Biomaterials—Approaches Towards 3D Tissue Printing

“…Experiments to print chitosan scaffolds with a dispensing-based RP technique were performed to validate the model. Results showed a good agreement with the model predictions and also further studies with alginate-hydroxyapatite hydrogels corroborated the mathematical model [81]. Monte Carlo simulations were performed assigning liquid-like properties to the tissue and gel-tissue interfacial tension as control parameter [141].…”

“…Gelation of the hydrogels has to be induced by crosslinking or polymerization and the maintenance of the 3D structural integrity during and after the assembling stage has to be guaranteed [96]. By accomplishing these requirements, gel structures can be manufactured with a controlled architecture (Figure 3) [73,81,97,98]. Once the hydrogel and its gelation method are established, it can be used as cell supporting structure by either seeding cells onto the printed construct or encapsulating cells prior to printing by assuming biofriendly fabrication conditions.…”

Mapping Glycosaminoglycan–Hydroxyapatite Colloidal Gels as Potential Tissue Defect Fillers

“…Such limitations could be improved by incorporating large biomolecular polymers into the suspending fluid phase. 6,21,24−31 Polymer solutions exhibit a significant increase in viscosity with concentration due to increased entanglements or associations between polymer chains in the solution. 32−35 Additionally, polyelectrolytes (i.e., charged polymers) may be leveraged in a charged colloidal system to improve particle–polymer interactions to induce cohesiveness in the colloidal gel.…”

Experimental and linear analysis for the instability of non‐Newtonian liquid jets issuing from a pressurized vibrating nozzle

“…The dispersion equation 31 is obtained when expressions (25) and (30) are introduced to define the normal stress boundary condition (23)…”

“…In particular, most polymeric solutions exhibit a viscoelastic behavior, which means that they display viscous but also elastic effects. 25,26 Flow curves give us information about a characteristic zero-shear viscosity and a measure of relaxation time. The Cross model 27 (38) resulted in the generalized Newtonian model that better fitted the data for all alginate solutions tested…”