Modeling Material-Degradation-Induced Elastic Property of Tissue Engineering Scaffolds

Abstract

The mechanical properties of tissue engineering scaffolds play a critical role in the success of repairing damaged tissues/organs. Determining the mechanical properties has proven to be a challenging task as these properties are not constant but depend upon time as the scaffold degrades. In this study, the modeling of the time-dependent mechanical properties of a scaffold is performed based on the concept of finite element model updating. This modeling approach contains three steps: (1) development of a finite element model for the effective mechanical properties of the scaffold, (2) parametrizing the finite element model by selecting parameters associated with the scaffold microstructure and/or material properties, which vary with scaffold degradation, and (3) identifying selected parameters as functions of time based on measurements from the tests on the scaffold mechanical properties as they degrade. To validate the developed model, scaffolds were made from the biocompatible polymer polycaprolactone (PCL) mixed with hydroxylapatite (HA) nanoparticles and their mechanical properties were examined in terms of the Young modulus. Based on the bulk degradation exhibited by the PCL/HA scaffold, the molecular weight was selected for model updating. With the identified molecular weight, the finite element model developed was effective for predicting the time-dependent mechanical properties of PCL/HA scaffolds during degradation.

Composite clinoptilolite/PCL‐PEG‐PCL scaffolds for bone regeneration: In vitro and in vivo evaluation

“…Enzymatic cleavage of PCEC by lipase might have induced bulk degradation by which polymer chains were broken without an immense weight loss. Compressive stress caused propagation of chain movement due to decrease in ester bonding after degradation, which led to declined UTS and CM (Bawolin, Li, Chen, & Zhang, ). Díaz, Sandonis, and Valle () fabricated nanoHAp (nHA)/PCL scaffold and observed higher mechanical strength and higher weight loss with nHA/PCL scaffolds than pure PCL counterparts (Díaz et al, ).…”

Determination of intrinsic birefringence values of polycaprolactone filaments

“…It responds to changes in crystallinity and orientation of macromolecules. For an unoriented filament sample, the sonic modulus E u is related to crystallinity by the following equation provided the Poisson's ratio of the polymer, is assumed to be 1/3: Here, $E^{0}_{\rm {t, c}}$ and $E^{0}_{\rm {t, am}}$ are intrinsic sonic lateral moduli of crystalline and amorphous regions, respectively, and β is the degree of crystallinity. The intrinsic lateral modulus is defined as Young's modulus for a perfectly oriented crystalline/amorphous material observed in the transverse direction .…”

Computed Tomography Diffraction-Enhanced Imaging forIn SituVisualization of Tissue Scaffolds Implanted in Cartilage

“…For example, one can employ finite element models that use measurable structural parameters as input for simulations that evaluate changes in scaffold mechanical properties with time. 17 Interestingly, even the surgical suture that was used for suturing and closing the inner site of incision was visualized in the DE image (Fig. 7B).…”