Poly (Butylene Adipate-Co-Terephthalate) and Poly (ε-Caprolactone) and Their Bionanocomposites with Cellulose Nanocrystals: Thermo-Mechanical Properties and Cell Viability Study

Although nanocomposites have recently attracted special interest in the tissue engineering area, due to their potential to reinforce scaffolds for hard tissues applications, a number of variables must be set prior to any clinical application. This manuscript addresses the evaluation of thermo-mechanical properties and of cell proliferation of cellulose nanocrystals (CNC), poly(butylene adipate-co-terephthalate) (PBAT), poly(epsilon-caprolactone) (PCL) films and their bionanocomposites with 2 wt% of CNC obtained by casting technique. Cellulose nanocrystals extracted from Balsa wood by acid hydrolysis were used as a reinforcing phase in PBAT and PCL matrix films. The films and pure CNC at different concentrations were cultured with osteoblasts MG-63 and the cell proliferation was assessed by AlamarBlue (R) assay. The thermal-mechanical properties of the films were evaluated by dynamic-mechanical thermal analysis (DMTA). It was found by DMTA that the CNC acted as reinforcing agent. The addition of CNCs in the PBAT and PCL matrices induced higher storage moduli due to the reinforcement effects of CNCs. The cell viability results showed that neat CNC favored osteoblast proliferation and both PBAT and PCL films incorporated with CNC were biocompatible and supported cell proliferation along time. The nature of the polymeric matrix or the presence of CNC practically did not affect the cell proliferation, confirming they have no in vitro toxicity. Such features make cellulose nanocrystals a suitable candidate for the reinforcement of biodegradable scaffolds for tissue engineering and biomedical applications.