Current treatment for pelvic organ prolapse (POP) and stress urinary incontinence (SUI) involves transvaginal implantation of surgical mesh, conventionally made of polypropylene (PP). However, it has recently become apparent that the mechanical properties of PP are unsuitable, resulting in serious complications such as tissue erosion. In this study, thermoplastic polyurethane (TPU) was chosen as an alternative material, and hormone-loaded meshes were produced by fused deposition modelling (FDM). Filaments containing various concentrations (0%, 0.25%, 1%) of 17-ß-estradiol (E2) were prepared by hot-melt extrusion (HME) and were 3D printed into meshes with various geometries. The resulting meshes were characterised through a variety of instruments such as attenuated total reflection-Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), thermal analysis, fracture force and in vitro release studies. The results showed that E2 was homogeneously distributed throughout the TPU matrix. Moreover, the thermogravimetric analysis (TGA) showed degradation temperatures above those used during the FDM process, showing that the meshes can be produced below the degradation temperatures of the materials. The fracture force testing showed that material and mesh geometry influence mechanical properties, with TPU meshes appearing more elastic and therefore more suitable for pelvic floor repair than PP mesh. However, interestingly the mechanical properties of the TPU70 filament was not affected by the inclusion of E2. In addition, the 3D printed meshes showed a linear E2 release profile over a two weeks period, which can be modified according to the percentage of E2 added to the 3D printed construct. This proof of concept study demonstrates the potential of using FDM to create a new generation of safer mesh implants.
Pelvic Organ Prolapse , Surgical Mesh , Estradiol , Humans , Polypropylenes , Printing, Three-Dimensional
Pelvic Organ Prolapse (POP) and Stress Urinary Incontinence (SUI) are two prevalent disorders affecting 30-40% of women worldwide. Current strategies to repair or improve these medical conditions are non-surgical options such as physiotherapy, or surgical options such as the use of vaginal meshes. The synthetic material polypropylene (PP), which has long been used for manufacturing these vaginal meshes, is associated with severe complications such as chronic pain, infection or mesh erosion. As a result of a widespread reporting and unacceptably high rates of complications, these issues have become a public health concern. Regulatory bodies have recently deemed the transvaginal placement of PP mesh in the pelvic floor (PF) no longer a suitable treatment method for PF repair, leading to the need for a novel approach to the manufacture and selection of materials for urogynecological meshes. Medical devices, such as vaginal meshes can be manufactured using a variety of techniques including injection moulding, electrospinning, hot-melt extrusion (HME) or more recently 3D printing. Over the past decade, the use of 3D printing within the medical device industry has expanded and offers a promising approach to manufacture patient-specific surgical mesh when combined with imaging tools. This review will summarise the current strategies to treat POP and SUI, the issues and use of current meshes for the treatment of these pelvic floor disorders (PFDs), and the future directions for the manufacture of more suitable urogynecological meshes, as well as their potential materials.
Pelvic Organ Prolapse/surgery , Polymers/chemistry , Surgical Mesh , Technology, Pharmaceutical/methods , Vagina , Adrenal Cortex Hormones/administration & dosage , Anti-Bacterial Agents/administration & dosage , Biocompatible Materials/chemistry , Equipment Design , Equipment Failure , Female , Humans , Materials Science , Pelvic Organ Prolapse/complications , Polypropylenes/adverse effects , Printing, Three-Dimensional , Urinary Incontinence, Stress/etiology
Current strategies to treat pelvic organ prolapse (POP) or stress urinary incontinence (SUI), include the surgical implantation of vaginal meshes. Recently, there have been multiple reports of issues generated by these meshes conventionally made of poly(propylene). This material is not the ideal candidate, due to its mechanical properties leading to complications such as chronic pain and infection. In the present manuscript, we propose the use of an alternative material, thermoplastic polyurethane (TPU), loaded with an antibiotic in combination with fused deposition modelling (FDM) to prepare safer vaginal meshes. For this purpose, TPU filaments containing levofloxacin (LFX) in various concentrations (e.g., 0.25%, 0.5%, and 1%) were produced by extrusion. These filaments were used to 3D print vaginal meshes. The printed meshes were fully characterized through different tests/analyses such as fracture force studies, attenuated total reflection-Fourier transform infrared, thermal analysis, scanning electron microscopy, X-ray microcomputed tomography (µCT), release studies and microbiology testing. The results showed that LFX was uniformly distributed within the TPU matrix, regardless the concentration loaded. The mechanical properties showed that poly(propylene) (PP) is a tougher material with a lower elasticity than TPU, which seemed to be a more suitable material due to its elasticity. In addition, the printed meshes showed a significant bacteriostatic activity on both Staphylococcus aureus and Escherichia coli cultures, minimising the risk of infection after implanting them. Therefore, the incorporation of LFX to the TPU matrix can be used to prepare anti-infective vaginal meshes with enhanced mechanical properties compared with current PP vaginal meshes.
