Effects of Poloxamers as Excipients on the Physicomechanical Properties, Cellular Biocompatibility, and In Vitro Drug Release of Electrospun Polycaprolactone (PCL) Fibers.

Abstract

Electrospun microfibers are emerging as one of the advanced wound dressing materials for acute and/or chronic wounds, especially with their ability to carry drugs and excipients at a high loading while being able to deliver them in a controlled manner. Various attempts were made to include excipients in electrospun microfibers as wound dressing materials, and one of them is poloxamer, an amphiphilic polymer that exhibits wound debridement characteristics. In this study, we formulated two types of poloxamers (i.e., P188 and P338) at 30% (w/w) loading into electrospun polycaprolactone (PCL) fibers to evaluate their physicomechanical properties, biocompatibility, and in vitro drug release of a model drug. Our findings showed that the incorporation of poloxamers in the PCL solutions during electrospinning resulted in a greater "whipping" process for a larger fiber deposition area. These fibers were mechanically stiffer and stronger, but less ductile as compared to the PCL control fibers. The incorporation of poloxamers into electrospun PCL fibers reduced the surface hydrophobicity of fibers according to our water contact angle studies and in vitro degradation studies. The fibers' mechanical properties returned to those of the PCL control groups after "dumping" the poloxamers. Moreover, poloxamer-loaded PCL fibers accelerated the in vitro release of the model drug due to surface wettability. These poloxamer-loaded PCL fibers were biocompatible, as validated by MTT assays using A549 cells. Overall, we demonstrated the ability to achieve a high loading of poloxamers in electrospun fibers for wound dressing applications. This work provided the basic scientific understanding of materials science and bioengineering with an emphasis on the engineering applications of advanced wound dressings.