Nature derived scaffolds for tissue engineering applications: Design and fabrication of a composite scaffold incorporating chitosan-g-D,L-lactic acid and cellulose nanocrystals from Lactuca sativa L. cv green leaf

Through exhaustive extraction via successive alkali and bleaching treatments cellulose was isolated from lettuce. The isolated cellulose was hydrolyzed using 64 wt% H₂SO₄ at 55 °C under constant stirring for 1 h to obtain cellulose nanocrystals (CNCs). Characterizations such as SEM, TEM, FTIR, TGA and XRD were done in order to determine differences in the physico-chemical characteristics of cellulose after each treatment step. The isolated CNCs have mean dimensions of 237 ± 26, 33 ± 12 and 32 ± 7 nm in length, thickness and height, respectively. These nanocrystals were incorporated to the formulations that were used to fabricate different chitosan-g-D,L-lactic acid (CgLA) scaffolds. Amide linkage formation between chitosan and lactic acid and further removal of water was facilitated by oven-drying under vacuum at 80 °C. Results show that an increase in the concentration of CNCs added, increase in porosity, degradability, drug release property and cell viability were observed from the fabricated composite scaffolds. These results can provide information on how nanofillers such as CNCs can alter the properties of tissue scaffolds through the chemical properties and interactions they provide. Moreover, these characteristics can give new properties that are necessary for certain tissue engineering applications.