A multicompartment vascular implant of electrospun wintergreen oil/ polycaprolactone fibers coated with poly(ethylene oxide)

Abstract

Background: The aim of the present study was to fabricate double layered scaffolds of electrospun polycaprolactone (PCL) and poly(ethylene oxide) (PEO). The electrospun PCL fibers were functionalized with wintergreen oil (WO) as a novel approach to prevent vascular grafts failure due to thrombosis by adjusting biomaterial-blood interactions.

Methods: PCL tubular scaffolds were prepared by electrospinning approach and coated with PEO as a hydrophilic polymer. The single and double layered scaffolds were characterized in terms of their morphological, chemical properties -as well as-hemocompatibility assays (i.e. prothrombin time, hemolysis percentage and platelets adhesion). Moreover, the antioxidant potential of WO-PCL samples were measured by 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical assay.

Results: The results demonstrated that incorporation of WO during the electrospinning process decreased the PCL fiber diameter. In addition, the prothrombine time assay shows that WO could be used to lower the electrospun PCL fiber tendency to induce blood clotting. Moreover, SEM observations of platelets adhesion of both single and double layered PCL/PEO scaffolds fiber shows an increase of platelets number, compared with the scaffolds containing WO.

Conclusions: The antioxidant potential and blood compatibility measurements of WO-PCL/PEO samples highlight the approach made so far as an ideal synthetic small size vascular grafts to overcome autogenous grafts shortages and drawbacks.

Keywords: Blood compatibility; Electrospun vascular grafts; Poly(ethylene oxide) (PEO); Polycaprolactone (PCL); Wintergreen oil (WO).

Fig. 1

Optimization of processing parameters (A, B& C) obtained fibers at 15 kV and distance of 10 cm for solution conc. of 6, 8 &10%, respectively, (D& E) effect of applied voltage 17 and 20 kv, (F) WO1-PCL solution conc. of 8%, (G, H& I) WO1-PCL, WO2-PCL WO3-PCL solution conc. of 10%, respectively.

Fig. 2

SEM micrographs of double layered mats (A) PCL coated PEO solution of 5%, (B) PCL coated PEO solution of 10%, (C) PCL/PEO-Hep and (D) WO1-PCL/PEO-Hep.

Fig. 3

FTIR spectra of pure WO, PEO and PCL - as well as fabricated WO1-PCL electrospun mats and double layered mats of WO1-PCL/PEO.

Fig. 4

Represents water uptake percentage of fabricated PCL and PCL/PEO double layered fibers. The inserted photograph of fabricated tubular scaffolds which was obtained using a rotating mandrel to develop a vessel like structure of electrospun PCL fibers. Data are evaluated as mean values ± SD for three experiments. Differences between the samples were determined using the unpaired t-test (∗p ≤ 0.01).

Fig. 5

Shows the remaining DPPH % for WO1-PCL and WO2-PCLsamples after different time intervals. The antioxidant potential was calculated and expressed as mean values ± SD for five experiments (p ≤ 0.01).

Fig. 6

Represents blood compatibility assay of fabricated single and double layered mats (A) Prothrombin assay and (B) Hemolysis assay. Data were evaluated as mean values ± SD for five measurements (∗p ≤ 0.01).

Fig. 7

SEM micrograph of adhered plated on the surface of (A) Electrospun PCL mats,(B) PCL/PEO mats,(C) WO1-PCL/PEO mats, (D) WO1-PCL/PEO-Hep, (E) Higher magnification of adhered platelet on the surface of PCL/PEO and (F) adhered platelet on WO1-PCL/PEO.