Vaterite coatings on electrospun polymeric fibers for biomedical applications

The process of porous calcium carbonate (CaCO₃ ) covering on electrospun poly(ε-caprolactone) (PCL) fibers is described in this study. Uniform CaCO₃ coatings, composed of vaterite microparticles and its aggregates, were formed on PCL fibers by mineral precipitation from solution under ultrasonic treatment. The porous structure of CaCO₃ in vaterite polymorphic form is useful for loading of various substances (drugs and nanoparticles), and this property makes vaterite an appropriate material for design of drug delivery systems. Such mineralization was implemented to attain therapeutic and/or biological activity of tissue engineering scaffolds based on electrospun PCL, by means of CaCO₃ coatings. Various structures and polymorphs of CaCO₃ coatings were obtained by variation of growth conditions (time of fiber incubation in work solution, ultrasonic treatment of this system). Coating homogeneity, CaCO₃ polymorphic form, morphology, and CaCO₃ mass can be controlled by number of successive stages of fibrous material treatment. Cytotoxicity tests showed that PCL fibers mineralized with CaCO₃ did not release substances toxic for cells. SEM images of PCL/CaCO₃ scaffolds cultured with cells demonstrate that scaffolds supported cell adhesion and spreading. The presented results show the new technique of controlled PCL scaffold mineralization with vaterite, and an opportunity of using PCL/CaCO₃ as scaffolds for tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 94-103, 2017.