Fabrication of a microvesicles-incorporated fibrous membrane for controlled delivery applications in tissue engineering.

A scaffold, which can provide mechanical support for tissue regeneration and simultaneously release functionally active biomolecules are highly desirable for tissue engineering applications. Herein, we report the fabrication of a fibrous mesh of polycaprolactone (PCL) incorporating PCL-pluronic (F127) microvesicles through electrospinning, by exploiting the slow dissolution of PCL in glacial acetic acid (g-AA). Micro-vesicles 1-10 μm in diameter were fabricated through a non-solubility driven spontaneous self-assembly and stabilization of F127 with low molecular weight PCL in tetrahydrofuran-water mixture. Time-dependent stability of the vesicles in g-AA was confirmed prior to the electrospinning. The electrospun membrane was found to be comprised of microvesicles entangled in a fibrous mesh of PCL with a fiber diameter ranging from 50-300 nm. Significant reduction in the release rate of rhodamine-B, an indicator dye from the electrospun membrane, when compared to that from the vesicle alone, evidences the surface coating of the vesicles with high molecular weight PCL during electrospinning. The vesicle incorporated membrane exhibited increased hydrophilicity when compared to the control PCL membrane, possibly due to surface unevenness and the hydrophilic F127. This enhanced surface hydrophilicity led to an increased cell viability of L929 cells on the membrane.