Mechanical viability of a thermoplastic elastomer hydrogel as a soft tissue replacement material

Abstract

Hydrogels are a class of synthetic biomaterials composed of a polymer network that swells with water and as such they have both an elastic and viscous component making them ideal for soft tissue applications. This study characterizes the compressive, tensile, and shear properties of a thermoplastic elastomer (TPE) hydrogel and compares the results to published literature values for soft tissues such as articular cartilage, the knee meniscus, and intervertebral disc components. The results show the TPE hydrogel material is viscoelastic, strain rate dependent, has similar surface and bulk properties, displays minimal damping under dynamic load, and has tension-compression asymmetry. When compared to other soft tissues it has a comparable equilibrium compressive modulus of approximately 0.5MPa and shear modulus of 0.2MPa. With a tensile modulus of only 0.2MPa though, the TPE hydrogel is inferior in tension to most collagen based soft tissues. Additional steps may be necessary to reinforce the hydrogel system and increase tensile modulus depending on the desired soft tissue application. It can be concluded that this material could be a viable option for soft tissue replacements.

A novel mechanobiological model can predict how physiologically relevant dynamic loading causes proteoglycan loss in mechanically injured articular cartilage

“…Similar approaches for iterative tissue adaptation as applied here have been used to study cartilage mechanics 24 , 54 – 57 , bone remodeling 29 , 58 – 62 and tissue engineering characterization 63 , 64 . A critical factor in the model generation and simulation is the selection of the degeneration thresholds.…”

Study of the Influence of the Manufacturing Parameters on Tensile Properties of Thermoplastic Elastomers

“…These materials combine the thermoplastic nature of polymers along with high elasticity. Hence, these types of materials, which might be similar to soft tissues because of their mechanical properties, have gained interest in biomedical research [7,8]. Bachtiar et al [9] characterized the elastomer PCU-Sil processed through 3D printing, suggesting possible biomedical applications.…”

Effect of network connectivity on the mechanical and transport properties of block copolymer gels

“…These properties consequently afford gels the capacity to satisfy a number of applications. Such applications include flexible electronics and fuel cells, 1,2 3D printable media, 3 filtration of both liquid 4 and gaseous 5 media, and biomedical applications including soft tissue replacement, 6,7 and drugdelivery vehicles. 8,9 While hydrogels have fulfilled several of these roles, particularly in the realm of drug delivery, lesser-studied organogels are also capable of satisfying many of these applications [10][11][12][13] and have even been proposed recently as transdermal drug delivery devices.…”