Preparation and Application of Rehmannia Glutinosa Extract Incorporated Functional Chitosan Based Biomaterials

The main objective of this work is to prepare Rehmannia glutinosa extract (RE) incorporated functional chitosan (CH) based biomaterials and evaluate their physical properties, RE release properties, inhibitory effect of melanogenesis, and antioxidant and elastase inhibitory activities. RE incorporated CH based biomaterials were synthesized by a casting method and UV curing process. The surface and cross sections of prepared biomaterials were characterized by a field emission scanning electron microscope (FE-SEM). The physical properties such as tensile strength and elongation at break were also investigated. To apply the transdermal drug delivery system, RE release properties were examined with pH 4.5, 5.5, and 6.5 buffer solutions and artificial skin test at 36.5 degrees C. Results indicated that RE release of RE incorporated biomaterials with/without the addition of plasticizers [glycerol (GL) and citric acid (CA)] at pH 6.5 was about 1.10 times higher than that of at pH 4.5. In addition, results of the artificial skin test verified that RE was released constantly for 6 h. To verify the applicability of the prepared biomaterials, tyrosinase, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and elastase assays were investigated. Results indicated that RE incorporated biomaterials added CA exhibited tyrosinase activation, DPPH radical scavenging activity rate, and elastase activation of 45.12, 89.40, and 59.94%, respectively.