Effect of Gamma Irradiation and Simulated Physiological Conditions on the Physicochemical Properties of a 3D-Printed βTCP Composite

This study investigates the effects of hydration, temperature, and γ-irradiation on the structural, thermal, and mechanical properties of Lactoprene® 7415, a linear block copolymer consisting of 74% lactide, 15% trimethylene carbonate, 11% ε-caprolactone repeating units, and 40 wt% β-TCP/Lactoprene® 7415 composite. Techniques including static and dynamic mechanical testing or differential scanning calorimetry have evidenced structural changes resulting from irradiation- or water-induced crystallinity, crosslinking, chain scission or plasticization. Notably, hydration and physiological temperatures reduced the mechanical properties but conferred hyperelastic characteristics to the polymeric and composite samples. γ-irradiation was detrimental for the mechanical properties, except for those of the pure polymer in dry conditions. Our results evidence a complex interplay between the polymer, particles, temperature, hydration and water. Such observations could have implications in future designs and investigations of composite materials for scaffold-guided bone regeneration (SGBR), such as sterilization processes or minimally invasive surgery.