Random and aligned electrospun poly(ε-caprolactone) (PCL)/poly(1,8-octanediol-co-citrate) (POC) fiber mats for cardiac tissue engineering using benign solvents

Abstract

• Electrospinning of PCL/POC using benign solvents. • Random and aligned PCL/POC fiber mats with suitable morphology. • Properties depend on blend composition, fiber orientation, and crosslinking density. • PCL/POC 2:1 ratio showed most suitable properties. • Fiber alignment led to improved cell attachment. Cardiac tissue engineering (CTE) is a rising field of research aiming to provide strategies to repair or regenerate damaged heart tissue after events like myocardial infarction. Here, poly(1,8-octanediol-co-citrate) (POC) has been blended with poly(ε-caprolactone) (PCL) and the blend polymer was electrospun using the benign solvents acetic acid and formic acid to develop cardiac patches for CTE. The fiber mats were thermally crosslinked under mild conditions. Random and aligned PCL/POC fiber mats were investigated with regard to their morphological and physico-chemical properties, their degradation behavior, and their cytocompatibility in vitro. Homogenous and defect-free fibrous structures with average fiber diameters of 0.61 and 1.11 µm were observed for 2:1 and 1:1 ratios of PCL/POC blends. The wettability as well as mechanical properties of the PCL/POC fiber mats were dependent on blend composition, crosslinking treatment, and fiber orientation. While the wettability of the fiber mats was in a suitable range, the mechanical properties even exceeded necessary values for CTE after 14 days of incubation in Dulbecco’s phosphate buffered saline (DPBS). The post-crosslinking of the fiber mats also increased the degradation resistance resulting in less acidic leaching and more stable fibers after 28 days in DPBS. Cytocompatibility tests with C2C12 cells demonstrated an excellent cytocompatibility of PCL/POC blends with a PCL/POC ratio of 2:1. Based on the obtained data, PCL/POC fiber mats made from benign solvents showed promising properties for applications in CTE as cardiac patches and should be subjected to further research to elucidate their in vitro and in vivo potential.