Investigation on baicalin-loaded chitosan film crosslinked by graphene oxide and its biocompatibility

Chitosan has good biocompatibility, in vivo biodegradability and certain physiological activity, which can be used as a drug carrier to stabilise and protect drug components, causing the promotion of drug absorption and controlling drug release. Using graphene oxide (GO) as a cross-linking agent, the functional groups in its lamellar structure can interact effectively with the functional groups in chitosan molecules, leading to enhanced mechanical properties and optimize the controlled drug-release behaviour. GO/chitosan composite films were prepared by the solution mixing method with various GO content and exhibit many hydrogen bonds between the GO and chitosan. There were no obviously agglomerated GO particles in the surface of composite films, and the lamellar structure can be observed in the cross section of the composite films. Differential thermal analysis (DTA) indicated that the addition of GO increased the stability of the chitosan film. The baicalin-loaded GO/Chitosan also exhibited pH dependent release behaviour, with an increasing release amount and rate at lower pH medium. In addition, the result of biological evaluations showed that the GO/Chitosan films had good cytocompatibility in vitro and histocompatibility at appropriate GO concentrations. This investigation offered a new pH-dependent drug carrier potentially applied for tumour and atherosclerosis treatment.