Aspirin-loaded electrospun poly(ε-caprolactone) tubular scaffolds: potential small-diameter vascular grafts for thrombosis prevention

Abstract

Thrombosis is the main cause of failure of small-diameter synthetic vascular grafts when used for by-pass procedures. The development of bioresorbable vascular scaffolds with localized and sustained intra-luminal antithrombotic drug release could be considered a desirable improvement towards a valuable solution for this relevant clinical need. For this aim, we present the fabrication and characterization of aspirin-loaded electrospun poly(ε-caprolactone) tubular scaffolds as a vascular drug-delivery graft. Three different drug concentrations were considered (i.e., 1, 5 or 10 % w/w). Although a fibrous structure was clearly observed for all the collected scaffolds, aspirin content was directly implied in the final microstructure leading to a bimodal fiber diameter distribution and fused fibers at crossing-points (5 or 10 % w/w). Mechanical response highlighted a direct relationship for modulus and stress at break with the aspirin content, while the elongation at break was not remarkably different for the investigated cases. The temporal drug release was strongly dependent from the amount of loaded aspirin, reaching a steady state release after about 50 h. Finally, the adhesion assay confirmed the capability of the electrospun scaffolds to reduce platelet adhesion/aggregation onto aspirin loaded polymeric fibers. Aspirin-loaded electrospun tubular scaffold could represent a feasible candidate to develop a novel bioresorbable drug-releasing graft for small-diameter vessel replacements.

Dipyridamole embedded in Polycaprolactone fibers prepared by coaxial electrospinning as a novel drug delivery system

“…Therefore, the release kinetics of DIP were analyzed using the mathematical model of Peppas [20], which has been widely used for the investigation of the release kinetics of pharmaceutical agents from polymeric scaffolds prepared by PCL [16,23,24].…”

“…The release exponents n of the obtained data were shown in Table 1. The drug release rate from the electrospun scaffolds depends on the method of preparation, the structural and geometrical characteristics of the scaffold, and the type of the drug encapsulated in the polymeric matrix [24]. Equation (3) was applied to the first 60% of the measured fractional release [20].…”

Pcl/Peg Electrospun Fibers as Drug Carriers for the Controlled Delivery of Dipyridamole

“…PCL has good miscibility properties, possesses mechanical stability and displays prolonged degradation. Moreover, it can be easily electrospun and can be used for long-term sustained delivery of pharmaceutical agents in the field of drug delivery and tissue engineering [9][10][11][12][13]. On the other hand, polyethylene glycol (PEG) is a water soluble polyether with a wide range of molecular weights that has been found to be biocompatible and has been used in hydrogels, for surface modification of other polymers to obtain co-polymers, control of protein adsorption and as an adhesion molecule [14].…”

Tissue Engineered Scaffolds for an Effective Healing and Regeneration: Reviewing Orthotopic Studies

“…The technical approach to address this issue is summarized into the well-known tissue engineering paradigm [3], and one of its key points specifically focuses on the definition of a viable and instructive scaffold for cell seeding, proliferation, migration, and differentiation in the case of stem cells. This statement implies a careful selection of: (i) the material(s) for scaffold fabrication, either synthetic or naturally derived, (ii) the most suitable technique that allows to deal with a substrate morphologically and mechanically similar to the ECM to be replaced, thus avoiding any mismatch with the surrounding tissue, (iii) possible surface treatments that can confer a positive biochemical profile to elicit a significant biological response, and (iv) drugs and/or growth factors to be loaded into the scaffold and subsequently released to enhance the final performance, avoiding, for instance, any side effect that can limit the therapeutic efficacy, for example, prevention of platelet adhesion on the luminal surface of tissue engineered vascular grafts [4]. …”