## 3 Results  
Figure 6 illustrates the mechanical response of uniaxial stress-strain behavior for square-shaped mesh geometries printed with non-medical- (Figure 6A) and medical-grade PCL (Figure 6B). It also compares these responses with the mechanical behavior of vaginal tissue from a healthy sheep [38] and the polypropylene Restorelle mesh (Figure 5) [14,19,20]. The existing data on tensile tests for vaginal tissue and Restorelle(r) (control mesh) are based on stress-strain response. To accurately assess the information, the load-displacement data for the printed meshes were converted to stress-strain data by assuming a nominal  
Figure 5: SEM image of a Restorelle® synthetic mesh. Figure 6: Uniaxial stress–strain response of square-shaped mesh geometry printed with (**A**) non-medical-grade PCL and (**B**) medical-grade PCL compared to sheep vaginal tissue and Restorelle® mesh. Note: Fd_1L and Fd_2L refer to meshes printed with one layer and two layers, respectively. rectangular cross-section for stress estimation (length \(\times\) width). By considering the displacement and the distance between the wedge grips, the strain could be estimated. To compare the mechanical behavior of the produced meshes with that of the control mesh and vaginal tissue, a deformation criterion corresponding to the comfort zone was established. The comfort zone for vaginal tissue stress and strain refers to a range of physiological conditions, mechanical forces, and deformations that the vaginal tissue can tolerate without causing discomfort, damage, or adverse effects [38]. The comfort zone was set at a deformation of 0.2 mm/mm. The Restorelle(r) mesh exhibited significantly greater stiffness compared to both the vaginal tissue and printed meshes, as shown in Figure 5, for both non-medical and medical grades. Printed meshes with a thickness of 240 \(\upmu\)m (2 layers) showed higher maximum stress--around 2.6 MPa for non-medical grade and 2.1 MPa for medical grade. When compared to the synthetic mesh (control mesh), the latter exhibited lower stress during the initial strain but experienced an increase in stress afterward, reaching 3.5 MPa within the comfort zone. When comparing meshes with one layer (filament diameter (Fd)_1L) and two layers ((Fd)_2L), it is evident that the meshes with two layers exhibit higher stress, as expected. Table 6 displays the mean values of the maximum stress for each material (non-medical and medical grade), highlighting significant differences. Figure 7 illustrates the stress-strain response of diagonal-shaped meshes under uniaxial tensile load, including curves for vaginal tissue and the Restorelle(r) mesh. This analysis focuses on meshes printed with medical-grade PCL, as previous comparisons demonstrated significant differences between medical- and non-medical-grade materials. Similarly to Figure 6, the two-layer meshes consistently display higher stress levels compared to their one-layer counterparts. For instance, the 160 \(\upmu\)m two-layer mesh reached a maximum stress of 0.75 MPa, while the one-layer version reached 0.48 MPa. Notably, the performance of most printed meshes, especially the 80 \(\upmu\)m single-layer mesh, aligns closely with the behavior of vaginal tissue. Table 7 presents the Secant modulus values for the square- and diagonal-shaped models with the 80_1L configuration, which demonstrated behavior most similar to vaginal tissue. The square-shaped mesh was analyzed for both non-medical- and medical-grade PCL, showing a difference of approximately 54% between the two materials. When comparing sheep vaginal tissue and the Restorelle(r) mesh, there was a notable difference of about 78%, reflecting the increased stiffness of the synthetic mesh compared to the biological tissue. The results indicate that medical-grade PCL offers a closer approximation to vaginal tissue. Specifically, the square-shaped mesh shows a better alignment with vaginal tissue, with a difference of only 13.7% in the Secant modulus, while the diagonal-shaped mesh has a larger discrepancy of 45%.