Electrospun Fibers as a Dressing Material for Drug and Biological Agent Delivery in Wound Healing Applications

Abstract

Wound healing is a complex tissue regeneration process that promotes the growth of new tissue to provide the body with the necessary barrier from the outside environment. In the class of non-healing wounds, diabetic wounds, and ulcers, dressing materials that are available clinically (e.g., gels and creams) have demonstrated only a slow improvement with current available technologies. Among all available current technologies, electrospun fibers exhibit several characteristics that may provide novel replacement dressing materials for the above-mentioned wounds. Therefore, in this review, we focus on recent achievements in electrospun drug-eluting fibers for wound healing applications. In particular, we review drug release, including small molecule drugs, proteins and peptides, and gene vectors from electrospun fibers with respect to wound healing. Furthermore, we provide an overview on multifunctional dressing materials based on electrospun fibers, including those that are capable of achieving wound debridement and wound healing simultaneously as well as multi-drugs loading/types suitable for various stages of the healing process. Our review provides important and sufficient information to inform the field in development of fiber-based dressing materials for clinical treatment of non-healing wounds.

Keywords: composites; drug release; electrospun fibers; gene vectors; proteins and peptides; small molecule drugs.

Figure 1

Schematics of typical wound healing cycles and the corresponding cellular activities in each stage.

Figure 2

(a) PDGF-BB (1.5 μg) was passively absorbed by PCL and PCL/col/HA fibers at 4 °C for 24 h using a PBS bath (300 μL); (b) In vitro release profiles of PDGF-BB from fibers over 56 days; (c) Release of PDGF-BB promoted MSCs migration using a stringent migration assay (inset shows fluorescent image of the MSC migration) [113]. An asterisk denotes p < 0.01. Figures were obtained from an open access article distributed under the Creative Commons Attribution License.

Figure 3

(a) Wound healing of a diabetic mouse (DM) model for comparison of effects on delivery of EGF cDNA and VEGF cDNA after 6 days; (b) Percent wound closure after receiving gene therapy from the mouse model; (c) Histology of the wound tissues from the animal model where tissues receiving EGF and VEGF showed restoration of the tissue structure [135]. Figures were obtained from an open access article distributed under the Creative Commons Attribution License.

Figure 4

(a) Diabetic skin wound using a rat model for comparison of control and those subjected to delivery of pbFGF polyplexes from electrospun poly(ethylene imine)/PEG (2 kDa) core/shell fibers (Fa2: blank fibers and Fb2: fibers with pbFGF polyplexes in the core); (b) In vitro release profiles of pbFGF from electrospun poly(ethylene imine)/PEG core/shell fibers (Fb2: 2 kDa PEG and Fb4: 4 kDa PEG); (c) Percentage of wound area from the diabetic rat model [143]. Reprinted with permission from American Chemical Society. Copyright (2017) American Chemical Society.

Figure 5

(a) Amphotericin B release profiles from micelles of phenylboronic acid-functionalized polycarbonate/PEG (denotes as B) and urea-functionalized polycarbonate/PEG (denotes as U) in comparison of free drug and Fungizone^® using dialysis; (b) Comparison of zone inhibition from C. albicans growth after applying amphotericin B containing micelles [149]. “***” denotes p < 0.001 and “ns” denotes no significant difference. Figures were obtained from an open access article distributed under the Creative Commons Attribution License.

Figure 6

(a) SEM image of fiber structure from PLCL; (b) SEM image of fiber structure from PLCL/poloxamer (9/1 w/w); (c) SEM image of fiber structure from PLCL/poloxamer (3/1 w/w); (d) Water contact angle of PLCL/poloxamer fibers; (e) Stress strain curves of PLCL/poloxamer fibers; (f) Adipose-derived stem cell proliferation on PLCL/poloxamer fibers [150]. Figures were obtained from an open access article distributed under the Creative Commons Attribution License.