Mechanical Properties of Composite Hydrogels for Tissue Engineering

Abstract

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 timeresolved 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.

Soft Actuated Hybrid Hydrogel with Bioinspired Complexity to Control Mechanical Flexure Behavior for Tissue Engineering

“…Both the loss and the storage modulus are higher in the samples were the HAp has more presence. This evidence was previously reported in different studies [ 5 , 55 ]. Furthermore, as it has been previously demonstrated, [ 56 , 57 ] the Ca atoms present on the HAp interact with the oxygen sites of alginate.…”

“…Finding new materials with the suitable properties to be used as extracellular matrix (ECM) substitutes has always been one of the major goals of the tissue engineering. In recent years, many works have focused on the study of polymeric hydrogels, since their properties of biocompatibility, biomimicry, receptivity, the possibility to adjust their mechanical properties, and their intrinsic ability to contain great amounts of water make them excellent substitutes of the ECM for biomedical applications [ 1 , 2 , 3 , 4 , 5 ]. Consequently, naturally derived polymeric hydrogels present themselves as flexible and adaptable scaffolds to mimic the natural features of native ECM such as the stimulation of tissue formation and maintain and conserve cellular functions [ 6 ].…”

Trimers Conjugated to Fibrin Hydrogels Promote Salivary Gland Function

“…Regarding rheologic properties, we performed oscillatory time sweeps, which are important when testing polymeric materials because they provide information on structural changes over time (Rial et al 2018). Particularly, these experiments were performed with a strain-controlled rheometer at a 100-μm gap at 37 °C.…”

Viscoelastic Cell Microenvironment: Hydrogel‐Based Strategy for Recapitulating Dynamic ECM Mechanics

“…As viscosity originates from energy dissipation, any change in molecular structure or conformation induced by mechanical stress or strain to dissipate energy will give rise to viscoelasticity. [ 60,61,129,130 ] There are several molecular sources or mechanisms that lead to viscoelasticity in hydrogels. For example, physical or non‐covalent crosslinking based on ionic interaction, [ 24–27 ] hydrogen bonding, [ 28–33 ] hydrophobic interaction, [ 34–37 ] metal‐ligand coordination, [ 38–40 ] self‐assembly, [ 41,42 ] and supramolecular interaction [ 43–46 ] is one important source of hydrogel viscoelasticity.…”