Mechanical Properties of Composite Hydrogels for Tissue Engineering

Tissue engineering provides solutions that require medicine to restore damaged tissues or even complete organs. This discipline combines biologically active scaffolds, cells and molecules; being the addition of nanoparticles into the scaffolds, one of the techniques that is attracting more interest these days. In this work, Hydroxyapatite Nanorods (HA) were added to the network of Gelatin hydrogel (GE), and the particular properties resulting from their interaction were studied. Specifically, viscoelastic properties were characterized as a function of gel and nanoparticle concentration, varying ratios and temperatures. Oscillatory Time Sweeps (OTS) provided the necessary information about how the time-resolved material property/structure alteration. A wide variety of Continuous Flow Tests and Frequency Sweeps were used to describe the mechanical properties of the material, proving that the presence of nanoparticles led to a reinforcement of the gel network, mechanical stiffness and strength. The thixotropic nature of the gels was also evaluated and the most common theoretical models were described and commented. The attributes inferred from the data, showed a material that can allow the natural growth of bone tissue whilst withstanding properly the mechanical efforts; resulting in a material with an outstanding suitability to be used in regenerative medicine.