Nanostructured Electrospun Polycaprolactone—Propolis Mats Composed of Different Morphologies for Potential Use in Wound Healing

Abstract

This study aimed to investigate different types of morphologies obtained using the electrospinning process to produce a material that enables wound healing while performing a controlled release. Using benign solvents, the authors prepared and characterised electrospun polycaprolactone mats loaded with propolis, a popular extract in traditional medicine with potential for skin repair. Different morphologies were obtained from distinct storage periods of the solution before electrospinning to investigate the effect of PCL hydrolysis (average diameters of fibres and beads: 159.2–280.5 nm and 1.9–5.6 μm, respectively). Phytochemical and FTIR analyses of the extract confirmed propolis composition. GPC and viscosity analyses showed a decrease in polymer molecular weight over the storage period (about a 70% reduction over 14 days) and confirmed that it was responsible for the nanostructure diversity. Moreover, propolis acted as a lubricant agent, affecting the spun solutions’ viscosity and the thermal properties and hydrophilicity of the mats. All samples were within the value range of the water vapour transpiration rate of the commercial products (1263.08 to 2179.84 g/m2.day). Even though the presence of beads did not affect the propolis release pattern, an in vitro wound-healing assay showed that propolis-loaded mats composed of beaded fibres increased the cell migration process. Thus, these films could present the potential for use in wound dressing applications.

Functional Electrospun Nanofibers Loaded with Plantago Major L. Extract for Potential Use in Cutaneous Wound Healing

“…%) in relation to that of the pure PCL solution, which may be related to a lubricant behavior of the molecules of the extract inside the polymeric network. This behavior was also observed in the results presented by Figueiredo et al (2022) [54], who observed the lubricant behavior on viscosity when incorporating propolis extract into the PCL solution.…”

“…For the second heating cycle, Figure 7(b), the PCL electrospun mats with the P. major extract showed a decrease of approximately 36.6 % in the degree of crystallinity of the fibers with 5.3 wt.% of the extract compared with PCL fibers without the extract (PCL_00) (Table 2). This demonstrates an interaction between freeze-dried extract and PCL chains that can be attributed to the fact that the P. major molecules were able to allocate themselves between polymer chains, promoting the increase in the space between them, and increase in the difficulty of these chains in reorganizing as ordered crystal structures [54,67]. Nevertheless, this large decrease in the degree of crystallinity was not observed when the concentration of the extract was increased to 10.6 wt.% (PCL_10.6), and a slight increase in crystallinity was observed with relation to PCL_5.3.…”

“…On the other hand, the PCL_10.6 sample, which showed total water absorption (CA = 0°), may be influenced by the two main phenomena, one related to the chemical character/composition of the extract, as well as, the capillarity of the mats, since a possible increase in the pores formed inside the fibers was verified. This feature generates a higher humectability capacity of their fibers compared to the other two samples evaluated [54,58]. It is well-known that a material with hydrophilic character may provide conditions for cell attachment, proliferation, migration, and differentiation.…”

“…However, three stages of mass loss at higher temperatures were seen in the PCL/P. major electrospun mats, two of them with maximum DTG mass loss rate (peak maximum) at 181 and 256 °C, attributed to components of extract, and one between 320-450 °C related to the stage of PCL chain degradation [54,68].…”

“…The PCL spinning study of this work started based on previous studies developed in our research group [37,54], with variations of solvent systems. The solution was prepared using PLC (10 wt.…”