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.

<abstract> <p>Water-soluble polymers possess great advantages in current drug delivery systems, such as fast delivery through polymer matrix dissolution as well as promoting solid dispersion of poorly water-soluble drugs. In this work, water-soluble polyvinyl alcohol (PVA) and polyethylene oxide (PEO) were blended (50/50) to electrospin with and without the incorporation of a model drug, melatonin (MLT), at various blend polymer concentrations. Results suggested that increasing blend PVA/PEO solution concentrations, up to 7 wt%, promoted the formation of smooth and defect-free drug-incorporating fibers with an average fiber diameter ranged from 300 to 700 nm. Mechanical properties of the blank and MLT-loaded PVA/PEO fibers showed dependence on fiber morphologies and fiber mat structures, due to polymer concentrations for electrospinning. Furthermore, the surface wettability of the blend PVA/PEO fibers were investigated and further correlated with the MLT release profile of the fibers. Results suggested that fiber mats with a more well-defined fiber structure promoted a linear release behavior within 10 minutes in vitro. These drug-incorporated fibers were compatible to human umbilical vein endothelial cells (HUVECs) up to 24 hours. In general, this work demonstrated the structure-property correlations of electrospun PVA/PEO fibers and their potential biomedical applications in fast delivery of small molecule drugs.</p> </abstract>

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