Development of novel vaginal meshes for pelvic floor dysfunctions management

Abstract

Pelvic floor dysfunctions (PFDs) are a series of pathological conditions affecting a significant portion of women worldwide, with pelvic organ prolapse (POP) being one of the most common among those disorders. POP, which consists in the descendance of pelvic organs from their physiological position, may be managed with surgical and non-surgical approaches, with the latter implying the use of meshes which are employed to confer more support to weak tissues and to put back in place the prolapsed parts. However, the significant number of post-operative complications correlated to the use of meshes, required a strict action from different regulatory organs, which tightly regulated the use and the marketing of these type of devices.

The work presented in this thesis focus on the development of meshes to be potentially used in POP management. Meshes were produced via melt-extrusion 3D printing and exploring different materials and material combinations: polycaprolactone (PCL), thermoplastic polyurethane (TPU), PCL/Levofloxacin (LFX), PCL/LFX/polyvinylidene fluoride (PVDF). The feasibility of the manufacturing process was assessed by investigating meshes’ thermal and physicochemical properties. The effect of mesh’s pore orientation (0°/90° and 45°/135°) and shape (square, hexagonal)on their final mechanical outcomes was assessed in tensile conditions. Young modulus (E), ultimate tensile strength (UTS) and maximum elongation (ME) were evaluated and compared to the biomechanical properties of the vaginal tissue. Meshes were characterised according to their in vitro behaviour, and in particular in terms of accelerated degradation, drug release, antibacterial potential and shelf stability.

Meshes described in the current work were successfully manufactured with no material degradation or chemical alteration. Meshes’ mechanical properties well resemble those of the vaginal tissue and were still comparable with the physiological ones even after one month of accelerated degradation. All the produced meshes were characterised by a burst release and were able to continuously release the drug for at least 3 days. Among the tested meshes, those characterised by a hexagonal design seemed to show the best biomechanical behaviour, and the inclusion of PVDF in the material formulation contributed to better control the release of the drug and to make the overall formulation more stable over time. The results presented in this work represent an optimal starting point for the future development of a new generation of surgical meshes for the treatment of PFDs.

Date of Award	May 2023
Original language	English
Sponsors	VCRS student scholarship
Supervisor	Davide Mariotti (Supervisor) & Alistair McIlhagger (Supervisor)