Hysteresis of a biomaterial: Influence of sutures and biological adhesives

Abstract

We studied the changes in energy consumption of samples of calf pericardium, when joined or not joined by sutures and adhesives, by means of hysteretic cycles. Sixty-four samples were subsequently subjected to tensile stress until rupture. An overlapping suture sewn in the form of a rectangle presented an acceptable mean resistance to rupture of over 10 MPa, although lower than the mean values in an unsutured control series where the mean resistance surpassed 15 MPa. The contribution of an acrylic adhesive to the resistance to rupture was negligible. The sutured samples that were reinforced with adhesives and had not been subjected to hysteretic cycles prior to rupture showed an anisotropic behavior. This behavior appeared to be lost in all the samples that underwent hysteretic cycles. We found an inflection point in the stress/strain curve following the stepwise increase in the load, with a value greater than and proximate to the final load applied. This inflection should be analyzed by means of microscopy. Finally, the mathematical relationship between the energy consumed and the stress applied, the strain or deformation produced and the number of cycles of hysteresis to which the samples were subjected was established as the ultimate objective of this study. The bonding systems provoked a greater consumption of energy, with the greatest consumption corresponding to the first cycle in all the series assayed. An equation relating the energy consumption in a sample to the number of hysteretic cycles to which it was subjected was obtained. Its asymptote on the x-axis indicates the energy consumption for a theoretical number of cycles, making it possible to estimate the durability of the sample.

Evaluation of transcatheter heart valve biomaterials: Biomechanical characterization of bovine and porcine pericardium

“…al reported UT S values obtained by burst testing of 61.15–67.12 MPa and 49.93–61.18 MPa for PP and BP tissues, respectively, and uniaxially of 19.66–23.34 MPa and 25.70–28.72 MPa for PP and BP tissues, respectively). The same group also reported uniaxial UT S range of 15.80–34.36 MPa from CBP tissues in a later study [11]. Uniaxial results by this group match well with our UT S values of 17.46–20.54 MPa and 21.08–22.43 MPa for PP and ABP/CBP tissues, respectively.…”

“…Although the mechanical properties of GL-treated BP tissue have been previously characterized through biaxial and uniaxial testing [9–14], the mechanical properties of BP and PP tissues have been compared primarily through uniaxial testing [11–13, 15]. To the authors’ knowledge, the only published study that has compared the mechanical response of younger, thinner BP with thicker, older BP tissue was performed by Sizeland et al [5] through uniaxial testing.…”

Changes in the Mechanical Properties of Chemically Treated Bovine Pericardium After a Short Uniaxial Cyclic Test

“…Once cut open, the pericardial sacs measured nearly 15 cm long, from root to apex, and approximately 10 cm wide. For their orientation and the subsequent cutting of the samples, the sacs were opened in such a way as to leave the diaphragmatic ligament in the center and the sternopericardial ligaments on the circumference (13).…”

“…The study of the hysteresis curve of a biomaterial subjected to cyclic loading reveals that the first hysteresis cycle, regardless of its initial load, is markedly different from that of the subsequent cycles subjected to the same force and, thus, the energy it loses is also different (13).…”

Mechanical strength of sutured block copolymers films for load bearing medical applications

“…The literature is mainly focused on examination of mechanical behaviour of sutured biological materials for cardiac bioprostheses, with leading contributions by Garcia Paez at al. [18][19][20][21][22][23][24]. There are no reports on tensile testing of sutured synthetic materials for soft polymeric cardiac prosthesis.…”