Controlled drug release from a polymer matrix by patterned electrospun nanofibers with controllable hydrophobicity

In this work, we investigated the relationship between the micro/nanostructures of electrospun nanofibrous layers on polymer materials and the corresponding surface hydrophobicity, and further evaluated the possibility of controlling drug release from a polymer matrix by adjusting the micro/nanopatterned electrospun structures on the surface. Polyvinyl butyral (PVB) polymer films with different PVB electrospun nanofibrous structures and patterns on the surface were prepared by controlling the density and patterns of the PVB electrospun nanofibers. The effects of the electrospun nanoscaled fibrous and micro-patterned structures on the hydrophobicity of the PVB film surface were investigated. The results showed that the surface hydrophobicity of PVB films could be controlled over a large range (water contact angle from 80° to 153.2°) by changing the density, distribution and the arrangement of the deposited electrospun nanofibers on the surface. Furthermore, the in vitro drug release characteristics of PVB polymer films with hydrophobic surface modifications were studied. The results indicated that the hydrophobic surface created by nanofibrous structures on the PVB film could reduce the drug release rate from the PVB polymer film, and the drug release profile could be further tuned by changing the pattern arrangement of the nanofibers on the surface of the materials. In summary, this study demonstrated a possible way to control the drug release from a polymer matrix by modifying the surface with different hydrophobic micro/nanostructures.