Nanofibrous biomimetic mesh can be used for pelvic reconstructive surgery: A randomized study.

BACKGROUND: Implantation of nonabsorbable polypropylene (PP) mesh in the vagina is the main surgical treatment for pelvic organ prolapse (POP); however, clinical outcomes remain controversial and far from satisfactory. In particular, reducing the exposure or erosion of vaginal implants to obtain improved functional reconstruction is challenging. There is an urgent need for the development of new materials and/or products for POP treatment. A nanofibrous biomimetic mesh was recently developed to address this issue. OBJECTIVE: In this study, the basic properties of the newly developed mesh, including structural characteristics, mechanical properties, biological response of human umbilical cord mesenchymal stem cells in vitro, and tissue regeneration and biocompatibility in vivo, were evaluated and compared with those of Gynemesh™PS. METHODS: Scanning electron microscopy and uniaxial tensile methods were used to evaluate microstructure and mechanical properties, respectively. Mesenchymal stem cell growth on the meshes was observed by fluorescence microscopy to visualize the expression of enhanced red fluorescent protein. Twenty-four mature female Sprague Dawley rats were randomly assigned to two groups: group 1 (nanofibrous biomimetic mesh, Medprin, Germany, n=12) and group 2 (Gynemesh(TM)PS, Ethicon, USA; n=12). The posterior vaginal wall was incised from the introitus, and the mesh was then implanted. Three implants of each type were tested for 1, 4, 8 and 12 weeks. Connective tissue organization, inflammation, vascularization, and regenerated tissue were histologically assessed. RESULTS: The nanofibrous biomimetic mesh is a relatively heavy material and exhibited lower porosity than Gynemesh(TM)PS. The new mesh was stiffer than Gynemesh(TM)PS (p<0.001) but supported human umbilical cord mesenchymal stem cell attachment. Erosion of the grafts did not occur in any animal. The nanofibrous biomimetic mesh was encapsulated by a thicker layer of connective tissue and was associated with significantly greater inflammatory scores compared with Gynemesh(TM)PS. At 12 weeks, the vascularization of the new mesh was greater than that of Gynemesh(TM)PS (p<0.05). No significant difference in the thickness of the smooth muscle layer following implantation was observed between the two groups (p>0.05). CONCLUSIONS: The nanofibrous biomimetic mesh is a candidate for reinforcing pelvic reconstruction. The mesh could be improved by decreasing its weight and stiffness and increasing its porosity. This mesh could serve as a carrier for stem cells in future regenerative medicine and tissue engineering research.

Study on poly(L-lactide-co-trimethylene carbonate): synthesis and cell compatibility of electrospun film.

The biomedical applications of poly(l-lactide) (PLLA) were limited by its high crystallinity. In this paper, the copolymerization of trimethylene carbonate (TMC) and l-lactide (LLA) was carried out to improve the flexibility of PLLA. The effects of feeding dose, reaction temperature and polymerization time were investigated, and the copolymers were characterized with (1)H nuclear magnetic resonance, Fourier transform infrared reflection, gel permeation chromatography differential scanning calorimetry, thermogravimetric analysis and x-ray diffraction. The copolymers were electrospun to form porous films to study their cell compatibility. The results showed that the composition of the copolymer was nearly the same as that in the feeding dose, and the molecular weight of the copolymer decreased with increasing TMC content. The decrease in the reaction temperature and polymerization time would increase the molecular weight, but the composition deviates from the feeding dose. NIH/3T3 mouse fibroblast cells were cultured on the electrospun films. The morphology and proliferation of the cells were studied. The results implied that the cell compatibility of poly(l-lactide-co-trimethylene carbonate) copolymer was much better than that of the PLLA homopolymer.