MATERIALS AND METHODS: Acellular meshes were engineered using liquid collagen. They underwent in vitro, mechanical and bench testing by surgeons. Sixty-nine male New Zealand rabbits were used to refine the design. The final prototype based on the TissueSpan patented technology was then implanted again in a 2 cm long urethral defect in 9 rabbits and in a 4 cm long defect in 6 dogs.
RESULTS: The TissueSpan technology platform allows for the manufacturing of tubular and rectangular meshes in different diameters and thicknesses. The tubular mesh acted as physical conduit to gap the urethral defect with a patent urethra demonstrated after 1month in both animal models. The mesh was absorbed within 1-3months. Spontaneous urothelial coverage of the mesh and smooth muscle cell migration into the surgical area was demonstrated even in a 4 cm long urethral defect. A first in man clinical trial was subsequently initiated.
CONCLUSION: The acellular mesh may have the potential to be an off-the-shelf product for substitution urethroplasty. Its mechanical properties allow surgeons to easily create a physical conduit while its material properties favor tissue remodeling. A large-scale clinical trial is still required to further confirm the safety, performance, and patient benefit of this new medical device.
METHODS: In this study, three research groups were created using cryogenic milling: pure nanocollagen (Pure NC), nanocollagen with 0.005% graphene oxide (NC + 0.005% GO), and nanocollagen with 0.01% graphene oxide (NC+0.01% GO). Characterization analyses included transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD), zeta potential (ZP), and polydispersity index (PDI).
RESULTS: TEM and SEM analysis revealed that nanocollagen groups alone exhibited particle sizes of less than 100 nm. FTIR spectroscopic investigations indicated the presence of amide A, B, and I, II, and III (1800 to 800 cm-1) in all nanocollagen study groups, with the characteristic C-O-C stretching suggesting the incorporation of graphene oxide (GO). XRD data exhibited broadening of the major peak as the proportion of GO increased from pure NC to the nanocollagen groups with GO. Zeta potential measurements indicated electrostatic attraction of the samples to negatively charged surfaces, accompanied by sample instability. PDI results depicted size diameters ranging from 800 to 1800 nm, indicating strong polydispersity with multiple size populations.
CONCLUSION: This research demonstrated that collagen can be successfully fabricated into nanoparticles with sizes smaller than 100 nm.