Elisabete Silva

Female pelvic organ prolapse (POP) is a gynecological disorder characterized by pelvic organ descent that significantly impacts quality of life. With increasing global burden, approaches for early diagnosis are essential. This study illustrates a patient-specific computational model of the pelvic cavity, updating the uterine and cervical geometric model and assigning cervical tissue properties. Three distinct uterine geometric models were assembled based on literature measurements and magnetic resonance images for comparison and validation. Human cervical properties were extrapolated from biomechanical testing of ovine pelvic tissues. Finite element simulations of the Valsalva maneuver were conducted to analyze the biomechanical effects of varying uterine morphology and tissue properties on the pelvic cavity, including the bladder neck, vagina, and uterosacral ligaments (USLs). Results show that a uterus with softer properties exhibits less vertical displacement and relies more on USL support than a stiffer one. Furthermore, uterine volume and morphology significantly influence pelvic dynamics: a larger uterus tends toward anteversion, while a smaller uterus increases vertical vaginal displacement (10.57 mm vs 6.04 mm) and requires greater USL support. Anatomical variations directly constrain bladder neck displacement. These computational advancements aim to enhance patient-specific modeling, assisting clinical decision making.

Female pelvic organ prolapse (POP) is a gynecological disorder characterized by pelvic organ descent that significantly impacts quality of life. With increasing global burden, approaches for early diagnosis are essential. This study illustrates a patient-specific computational model of the pelvic cavity, updating the uterine and cervical geometric model and assigning cervical tissue properties. Three distinct uterine geometric models were assembled, based on literature measurements and magnetic resonance images for comparison and validation. Human cervical properties were extrapolated from biomechanical testing of ovine pelvic tissues. Finite elements simulations of the Valsalva maneuver were conducted to analyze the biomechanical effects of varying uterine morphology and tissue properties on the pelvic cavity, including the bladder neck, vagina, and uterosacral ligaments (USLs). Results show that a uterus with softer properties assigned exhibits less vertical displacement and relies more on USLs support than a stiffer one. Furthermore, uterine volume and morphology significantly influence pelvic dynamics: a larger uterus tends toward anteversion, while a smaller uterus increases vertical vaginal displacement (10.57 mm vs 6.04 mm) and requires greater USLs support. Anatomical variations directly constrain bladder neck displacement. These computational advancements aim to enhance patient-specific modeling, assisting clinical decision-making.

Conventional synthetic meshes for pelvic organ prolapse (POP) frequently cause severe complications, such as tissue erosion, due to a profound mechanical mismatch with native tissue. This study proposes a novel biphasic composite scaffold combining a load-bearing melt electrowritten (MEW) polycaprolactone (PCL) framework with a compliant alginate–gelatin (Alg-Gel) hydrogel matrix. PCL meshes (1.5 and 2.0 mm pores) were infiltrated with varying Alg-Gel ratios (4:3 and 5:2) and structurally evaluated through mechanical testing, swelling/degradation assays in a simulated acidic vaginal environment (pH 4.3), and finite element analysis (FEA). Results demonstrated that the 1.5 mm PCL architecture provides a robust baseline to withstand physiological loads. Notably, the hydrogel matrix provides a viscoelastic damping effect that synergistically improves the overall mechanical stability of the composite. Furthermore, FEA accurately predicted the non-linear macroscopic response of the composite constructs. Modulating the Alg-Gel ratio also enabled precise tuning of swelling capacity (up to 1400%) and degradation kinetics. Ultimately, this biomimetic system offers a highly adaptable, tissue-like protective cushion with enhanced dynamic stability, presenting a versatile platform for future in vivovalidation.

Apical prolapse, a common form of Pelvic Organ Prolapse (POP), is often linked to weakened support structures such as the uterosacral (USL) and cardinal ligaments (CL), influenced by factors like vaginal childbirth, aging, and obesity. Although surgical mesh use is expected to increase, the Food and Drug Administration (FDA) banned polypropylene mesh for transvaginal anterior compartment prolapse in 2019 due to safety concerns, highlighting the need for alternatives such as biodegradable implants. This study developed four biodegradable mesh implants (square and sinusoidal geometries) mimicking the USL and CL. These were applied within a computational pelvic model to assess biomechanical behavior during the Valsalva maneuver and to explore different fixation methods (continuous, interrupted and simple stitch sutures). Baseline analysis of the healthy model established vaginal displacement under normal conditions. Without implant support, complete CL rupture increased displacement by 34%, and complete USL rupture raised displacement by 69%. Polycaprolactone implants consistently reduced anterior vaginal wall displacement in all impairment scenarios. Square implants mimicking the USL reduced displacement by up to 10% in cases of complete USL rupture with intact CL. Similarly, square implants mimicking the CL reduced displacement by up to 15% with complete CL rupture and healthy USL. Simulations with both ligaments impaired showed that USL contribute to support, while CL play a key role in stabilization. These findings demonstrate the potential of biodegradable implants to enhance POP repair. However, further studies are needed to evaluate long-term degradation and clinical applicability.

Additive manufacturing (AM) offers new opportunities for biomedical device design; however, its translation to soft-tissue reinforcement remains challenging, particularly in pelvic organ prolapse (POP) applications requiring mechanical performance and tissue compatibility. In this study, a hybrid AM approach combining melt electrowriting (MEW) and controlled post-processing was developed to fabricate biodegradable poly(ε-caprolactone) (PCL) cog threads for minimally invasive pelvic reinforcement. This integrated fabrication workflow enables the precise deposition of microscale fibers via MEW followed by localized mechanical modification, offering a versatile platform for tailoring graft architecture and anchoring geometry. Smooth filaments were first produced via MEW and subsequently post-processed to introduce barbs for mechanical anchorage. The resulting structures were mechanically characterized through uniaxial tensile testing and evaluated as reinforcement elements in ex vivo sow vaginal tissue using ball burst testing. The MEW-fabricated cog threads increased the ultimate load of vaginal tissue from 83 ± 20 N (control) to 126 ± 15 N, corresponding to a 51.8% improvement (p = 0.0477). Compared with commercial PCL cog threads reported in the literature (177.0 ± 5.4 N), the reinforced specimens achieved approximately 71% of the benchmark load. Owing to their intermediate stiffness profile, the MEW-fabricated cog threads reduced mechanical mismatch with soft tissue compared to high-stiffness commercial alternatives. These findings demonstrate the feasibility of hybrid MEW-based additive manufacturing strategies for engineering mechanically compatible, application-driven soft-tissue reinforcement systems.

Background: Pelvic organ prolapse (POP) motivates the development of temporary, biodegradable reinforcements that avoid the long-term drawbacks of permanent meshes. Barbed (cog) poly(ε-caprolactone) (PCL) threads are designed to self-anchor and enhance tissue–implant friction, promoting load redistribution during strain while gradually resorbing. Hypothesis: Compared with non-reinforced controls, PCL cog reinforcement would increase in vivo intravaginal contact forces under standardized loading—consistent with a mechanical reinforcement effect—and would attenuate over time with material resorption. Methods: A prospective longitudinal ovine pilot study (n = 5) was conducted. Intravaginal forces were recorded at 0, 10, 20, and 30 mm speculum openings before implantation (to establish a baseline) and at 90 and 180 days post-surgery using a calibrated force-sensing speculum. All measurements were performed on the same animals at each time point, following an identical protocol. Results: At 90 days post-implantation, intravaginal forces were significantly higher than controls, with the largest increase at 0 mm (+76.0%, p = 0.0003). At 180 days, forces remained above baseline but declined relative to 90 days (+55.3% vs. control, p = 0.0035). Significant reinforcement effects were observed exclusively at 0 mm, while differences at larger openings were smaller and not statistically significant. Conclusions: These findings support the mechanical feasibility of PCL cog threads as a temporary reinforcement strategy compatible with progressive resorption.

Pelvic organ prolapse (POP) affects many women and involves the displacement of pelvic organs due to weakened support structures. While synthetic meshes are used in surgeries to reinforce these structures, they can lead to complications due to poor biocompatibility and mechanical properties. Biodegradable meshes offer an innovative solution, providing flexible and strong support that enhances tissue reinforcement and reduces the risk of injuries. The main objective of this study is to enhance our understanding and provide valuable insights into the performance of vaginal tissue and mesh implants, which may contribute to the advancement of POP treatment methodologies. This study utilized melt electrowriting to 3D print biodegradable mesh implants with quadratic and cross‐shaped geometries, each with a thickness of 240 μm. Uniaxial and ball burst tests were performed on these meshes and sow's vaginal tissue to determine their mechanical properties, and a numerical simulation of the ball burst test was validated, allowing for accurate material representation. The results indicate that the placement of biodegradable PCL meshes in sow's vaginal tissue increases the maximum force by 14% to 20% during ball burst tests. Furthermore, the simulation effectively mimicked the experimental analysis, demonstrating a strong correlation with the experimental data for both the meshes and the tissue. The computational analysis for the quadratic‐shaped mesh revealed a maximum difference of 7%, while the vaginal tissue simulation exhibited a difference of approximately 6%. However, discrepancies were observed in the tissue reinforced with the mesh, where the simulation yielded a maximum error of 14%, which may be attributed to the complex interactions between the mesh and the tissue. This multifaceted approach, integrating simulation, material testing, and experimental validation, forms the foundation of in‐depth research into the mechanical behavior of vaginal tissue and mesh implants, making significant contributions to the field of POP treatment. Utilizing experimental analysis to validate numerical simulations is essential, as it allows for reducing the need for extensive randomized controlled trials (RCTs) and minimizing the use of animal testing once the simulations are validated.

Pelvic organ prolapse (POP) is a common pelvic floor disorder resulting from weakened supportive muscles and ligaments. Although the demand for surgeries involving surgical meshes is expected to increase, current options remain limited. In 2019, the Food and Drug Administration (FDA) banned polypropylene mesh for transvaginal anterior compartment prolapse due to safety concerns. This study aimed to develop and evaluate computational models of biodegradable implants made of polycaprolactone, designed to replicate the mechanical behavior of the uterosacral ligaments (USLs) and mitigate complications associated with traditional synthetic meshes. The goal was to assess whether such implants could effectively restore pelvic support under varying degrees of USLs damage. Sacrocolpopexy was simulated using two distinct implant geometries: three square and one sinusoidal configuration. These were integrated into a pelvic cavity computational model to evaluate performance during the Valsalva maneuver under conditions of 50% and 90% damage, as well as total rupture of the USLs. The model, established without implants, demonstrated that complete USL rupture led to an approximate 41% increase in vaginal displacement when contrasted with the healthy model. All implants demonstrated a beneficial effect, decreasing vaginal displacement. Some of these implants successfully reversed the damage-induced displacement, nearing the level of a healthy vaginal model. While further clinical and in vivo validation is essential, these findings illustrate a promising direction and contribute to the growing evidence supporting the potential of biodegradable meshes in POP surgery. However, current outcomes are derived from computational models and serve primarily as a biomechanical proof of concept.

Pelvic organ prolapse (POP) is a condition that progressively affects women, leading to an increased demand for new treatment techniques. The current standard treatment is surgical correction, often highly invasive with associated risks and a relatively high failure rate. This study proposes an alternative approach using injectable biodegradable cog threads, commonly used in facial lifting. The 360 ^∘ 4D barb threads, made of polycaprolactone (PCL), were tested to reinforce vaginal wall defects. Degradation and mechanical properties were evaluated after exposure to phosphate buffer solution (PBS) and potassium hydrogen phthalate (KHP) for 90 days and 180 days compared with a control group. Fourier transform infrared spectroscopy (FTIR) spectroscopy showed slight to moderate degradation over time in both media. Mechanical tensile tests revealed a reduction in maximum tensile strength by 13% to 19%, especially in PBS. However, cyclic tests indicated that the threads maintained significant mechanical strength, even after 100 load cycles, suggesting their potential for POP correction. The preliminary results from degradation and mechanical tests suggest that biodegradable PCL cog threads could serve as a promising new approach to prolapse correction, warranting further investigation.