Effects of polydimethylsiloxane grafting on the calcification, physical properties, and biocompatibility of polyurethane in a heart valve

Abstract

Segmented polyurethane (PU) has proven to be the best biomaterial for artificial heart valves, but the calcification of polyurethane surfaces causes serious problems in long-term implants. This work was undertaken to evaluate the effects of polydimethylsiloxane (PDMS) grafting on the calcification, biocompatibility, and blood compatibility of polyurethane. A grafted polyurethane film was compared with virgin polyurethane surfaces. Physical properties of the samples were examined using different techniques. The hydrophobicity of the polyurethane films increased as a result of silicone modification. The effects of surface modification of polyurethane films on their calcification and fibroblast cell (L 929) and platelet behavior were evaluated in vitro. Fourier transform infrared spectroscopy indicated the direct involvement of the polyether soft segments of the polymer in the calcification process. Scanning electron microscopy of films indicated that grafting of silicone rubber to the surface of polyurethane successfully prevented the calcification process. The morphology of fibroblast cells that adhered to the PU films and modified films was similar to that of controls and showed the same proliferation. On the other hand, grafting PDMS onto PU did not affect the amount of platelets that adhered to the polyurethane surfaces.

Development and evaluation of elastomeric hollow fiber membranes as small diameter vascular graft substitutes

“…This was evidenced by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) viability assay using this media on L929 fibroblasts for 24 hours [50]. Dabagh and coworkers did not observe fibroblast proliferation differences between Estane and PDMS-modified Estane surfaces after culture for 48 hours [51]. Wagner [52, 53] and Liska [54, 55] developed degradable electrospun PEU vascular grafts comparable to commercially-available materials, showing good biocompatibility with cells in vitro and good mechanical properties, although complex PEU chemistry and fabrication were required to ensure this compatibility.…”

Emerging Trends in Heart Valve Engineering: Part IV. Computational Modeling and Experimental Studies

“…19 An example of this type of testing is monitoring the effects of polydimethylsiloxane (PDMS) on calcification in vitro. 32,78,104,105 Scanning electron microscopy (SEM) and X-ray absorption near edge structure (XANES) were also used to investigate calcified native and bioprosthetic heart valves and to characterize morphology and chemical composition. 163 While in vitro calcification studies have been performed to test passive calcification deposition of the heart valves, it should be noted that these studies do not necessarily rule out the potential active calcification of the heart valves in vivo.…”

Self‐healing biomaterials

“…In situ detection and repair of biomaterials is particularly difficult due to the lack of adequate in vivo imaging techniques to detect failures and suitable minimally invasive methods to repair the damage. Overall, only substantially damaged or compromised biomaterials can be detected in situ , and if detected are generally retrieved and replaced 6–12…”

“…Overall, only substantially damaged or compromised biomaterials can be detected in situ, and if detected are generally retrieved and replaced. [6][7][8][9][10][11][12] The development of synthetic materials that autonomously repair in situ on the microscopic level before suffering macroscopic failures would significantly extend the lifetime of a given structure or device. This is precisely the motivation behind the newly emerging class of ''self-healing materials'' that are endowed with the intrinsic ability of self-repair in response to damage arising from physical and chemical stresses within its use environment.…”