The Study On The Bioadhesive Drug Delivery System Based On Graphene Oxide/Poly(Aacrylic Acid) Complex

The interpolymer complex can be formed by hydrogen bonding,Coulomb force and other secondary forces.It has important potentials on bioadhesive drug delivery due to its better properties than that of single component.This paper focused on exploring graphene oxide?GO?/poly?acrylic acid??PAA?complex processing factors,such as molecular weight of PAA,pH value and concentration.The results showed that the interpolymer complex can hardly be formed by PAA with smaller molecule weight?Mw³000?,but can be produced by PAA with higher molecule weight?Mw⁴50000?,and the amount of complex formation increased with increasing portion of PAA.The critical pH value was about3.62.The amount of complex increased with decreasing pH values when below the pH_crit,but decreased with increasing pH value when higher than pH_crit.The amount of interpolymer complex formed increased with the increase of the concentration of each component.The results of bioadhesive drug delivery of GO/PAA complex showed that its swelling behavior was related to the content of GO.The higher the propostion of GO is,the faster the swelling rate is as well as the longer the equilibrium time is.The drug release process of GO/PAA agent was in accordance with the“First order release”model.The release rate in pH=7.4 PBS solution was faster than that of pH=2.0 HCl solution,and with the decrease of GO,the release rate increased due to less physical crosslinking facilitated by GO.The adhesion properties of the drug loaded interpolymer complex were also investigated.It was revealed that with the increase of GO amount,the adhesion force weakened while the adhesion time elongated.At the same time,GO-GO/PAA bilayer agent was prepared by vacuum assisted self-assembly in order to reduce the ineffective release.The drug release process of GO-GO/PAA agent was in line with“Zero order release”model when the GO backing is stilling.The thicker the backing,the slower the release rate.In addition,RGO-GO/PAA bilayer agent,prepared through exposition to ultraviolet light to reduce GO backing,had less ineffective release than GO-GO/PAA.In summary,hydrogen-bonded complex GO/PAA possesses an excellent capability of controlled release especially for poorly soluble drugs such as5-Fluorouracil?5-FU?,and therefore has a good application potential in the field of bioadhesive drug delivery.