Generation of Porous Structure from Basil Seed Mucilage via Supercritical Fluid Assisted Process for Biomedical Applications

Mucilage's are plant derived natural polymer which are valuable due to their nontoxicity, low cost and nonirritating nature, with wide range of applications. In this work, extracted mucilage from basil seeds (BSM) was dried using three various drying methods including (1) laboratory oven drying (2) water substitution with organic solvent and laboratory oven drying and (3) water substitution with organic solvent and supercritical carbon dioxide (SC-CO2) gel drying process. The obtained products were characterized by SEM, BET and FTIR and were compared both qualitatively and quantitatively. The results of this study show that, using SC-CO2 assisted process, the 3-D BSM nanostructured networks were obtained with the pores size diameter about 40 nm, without any agglomeration. Furthermore, specific area of the final products was increased from 69 to 92 m2/g by SC-CO2 gel drying in compression with air gel drying. Our observations show that, the amount of solvent residual in the SC-CO2 dried product was affected by the weight of sample, CO2 addition rate and drying time. The residual amount of organic solvent (ethanol) for CO2 flow rate of 2 mL/min was found to be 8 ppm after 90 min drying time. The FTIR analyses indicated that the nature of final product did not change during supercritical drying procedure. Overall, the ability to form 3-D structures, and bio adhesive property make BSM as a suitable low cost polysaccharide for biomedical applications such as drug delivery medium, wound dressing and also tissue engineering.