Fabrication and characterization of poly-(ε)-caprolactone and bioactive glass composites for tissue engineering applications

•We fabricated bioactive glass composite sheets of PCL, borate, or silicate glass microparticles.•Degradation rates show that borate glass composite sheets were greater than silicate composite sheets.•Elastic modulus decreased with added glass, but varied by glass composition.•Neurite outgrowth was changed by the composition and pre-reaction of glass.

Much work has focused on developing synthetic materials that have tailored degradation profiles and physical properties that may prove useful in developing biomaterials for tissue engineering applications. In the present study, three different composite sheets consisting of biodegradable poly-ε-caprolactone (PCL) and varying types of bioactive glass were investigated. The three composites were composed of 50 wt.% PCL and (1) 50 wt.% 13–93 B3 borate glass particles, (2) 50 wt.% 45S5 silicate glass particles, or (3) a blend of 25 wt.% 13–93 B3 and 25 wt.% 45S5 glass particles. Degradation profiles determined for each composite showed the composite that contained only 13–93 B3 borate glass had a higher degradation rate compared to the composite containing only 45S5 silicate glass. Uniaxial tensile tests were performed on the composites to determine the effect of adding glass to the polymer on mechanical properties. The peak stress of all of the composites was lower than that of PCL alone, but 100% PCL had a higher stiffness when pre-reacted in cell media for 6 weeks, whereas composite sheets did not. Finally, to determine whether the composite sheets would maintain neuronal growth, dorsal root ganglia isolated from embryonic chicks were cultured on composite sheets, and neurite outgrowth was measured. The bioactive glass particles added to the composites showed no negative effects on neurite extension, and neurite extension increased on PCL:45S5 PCL:13–93 B3 when pre-reacted in media for 24 h. This work shows that composite sheets of PCL and bioactive glass particles provide a flexible biomaterial for neural tissue engineering applications.