Preliminary Characterization of a Polycaprolactone-SurgihoneyRO Electrospun Mesh for Skin Tissue Engineering

Abstract

Skin is a hierarchical and multi-cellular organ exposed to the external environment with a key protective and regulatory role. Wounds caused by disease and trauma can lead to a loss of function, which can be debilitating and even cause death. Accelerating the natural skin healing process and minimizing the risk of infection is a clinical challenge. Electrospinning is a key technology in the development of wound dressings and skin substitutes as it enables extracellular matrix-mimicking fibrous structures and delivery of bioactive materials. Honey is a promising biomaterial for use in skin tissue engineering applications and has antimicrobial properties and potential tissue regenerative properties. This preliminary study investigates a solution electrospun composite nanofibrous mesh based on polycaprolactone and a medical grade honey, SurgihoneyRO. The processing conditions were optimized and assessed by scanning electron microscopy to fabricate meshes with uniform fiber diameters and minimal presence of beads. The chemistry of the composite meshes was examined using Fourier transform infrared spectroscopy and X-ray photon spectroscopy showing incorporation of honey into the polymer matrix. Meshes incorporating honey had lower mechanical properties due to lower polymer content but were more hydrophilic, resulting in an increase in swelling and an accelerated degradation profile. The biocompatibility of the meshes was assessed using human dermal fibroblasts and adipose-derived stem cells, which showed comparable or higher cell metabolic activity and viability for SurgihoneyRO-containing meshes compared to polycaprolactone only meshes. The meshes showed no antibacterial properties in a disk diffusion test due to a lack of hydrogen peroxide production and release. The developed polycaprolactone-honey nanofibrous meshes have potential for use in skin applications.

Keywords: electrospinning; honey; polycaprolactone; skin.

Figure 1

(a) SEM images of electrospun meshes: (i) PCL, (ii) PCLSH10, (iii) PCLSH20, and (iv) PCLSH30 (scale = 1 µm). (b) (i) Mean fiber diameter and distribution of fiber diameters for (ii) PCL, (iii) PCLSH10, (iv) PCLSH20, and (v) PCLSH30 meshes.

Figure 2

WLI images of the surface topography of the electrospun meshes (a) PCL, (b) PCLSH10, (c) PCLSH20, and (d) PCLSH30 meshes; and (e) surface roughness of meshes.

Figure 3

XRD patterns of electrospun meshes. (a) General view and (b) magnified image of the peaks for all samples.

Figure 4

Electrospun mesh (a) carbon, (b) oxygen, (c) C-O, (d) C=O percentage ratios, and (e) FTIR spectrum.

Figure 5

Wettability of electrospun meshes. (a) Droplet on the mesh surfaces and (b) contact angle measurements at 0 s and 50 s.

Figure 6

(a) Representative tensile stress–strain curves, (b) Young’s modulus, (c) percentage strain break point, and (d) tensile stress at break point for the electrospun meshes.

Figure 7

Swelling in (a) SBF and (b) DMEM and degradation in (c) SBF and (d) DMEM of the electrospun meshes as a function of time.

Figure 8

Cell metabolic activity and viability of HDFs and hADSCs on the electrospun meshes. (a) HDF viability at days 3 and 14 (green = live, red = dead) (scale = 200 µm) and hADSC viability at day 1 and 14 (scale = 50 µm). Metabolic activity of (b) HDFs and (c) hADSCs at day 1, 3, 7, and 14. (d) Glucose content of PCL and PCLSH30 meshes up to 48 h.

Figure 9

Inhibition zone of PCL (top) and PCLSH30 (bottom) electrospun meshes on agar plates using the disk diffusion method. (a) S. aureus, (b) E. coli, and (c) P. aeruginosa (scale = 5 mm).