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Description
Introduction
Wound healing follows a five-stage process when skin tissue is injured, but factors like wound size and patient health may require additional interventions [1]. Tissue-engineered structures, especially electrospun meshes, offer enhanced regeneration by mimicking the skin’s extracellular matrix, promoting hemostasis, absorbing exudate, and minimizing scarring [2]. However, electrospinning of natural polymers pose challenges since some polymers are difficult to process [3]. This study focuses on producing polycaprolactone (PCL) electrospun meshes (ePCL) and biofunctionalizing them with chitosan (CS). This approach ensures consistent fiber production while introducing a bioactive polymer on the surface to support in situ wound healing. The biofunctionalized electrospun meshes were analyzed for their physicochemical and mechanical properties.
Methods
Electrospun meshes were produced from a 16 wt% PCL solution in acetone using a home-made electrospinning apparatus. After ePCL production, the fibers were modified with sodium hydroxide (NaOH) and then biofunctionalized with CS through carbodiimide coupling (EDC-NHS).
Results
The ePCL meshes were produced and subsequently biofunctionalized with different concentrations of CS, namely 0.05, 0.1 and 0.5 wt%, through an optimized procedure.
Morphological characterization was performed using SEM at 15kV where different concentrations of CS can be observed encapsulating the ePCL nanofibers without changing typical mesh morphology, although increasing fiber diameter and introducing rugosity. EDX analysis revealed that the condition of ePCL with 0.5 wt% of CS showed a smaller ratio of nitrogen in the sample when compared with the remaining percentages. To confirm the presence of CS on the electrospun fiber's surface ATR-FTIR was used as well.
The meshes hydrophilicity was evaluated by measuring water contact angles. The biofunctionalized ePCL meshes resulted in more hydrophobic surfaces until a concentration of 0.5 wt% CS, concentration at which a higher hydrophilicity was observed leading to complete water absorption.
Mechanical properties were evaluated using a texturometer analyzer to assess tensile strength at break (TSB), elongation at break (EB) and Young's modulus (YM). A subsequent increase in CS showed lower YM.
Discussion
FTIR-ATR analysis and SEM imaging with EDX confirmed the biopolymer's presence on the fiber surface, without closed pores, for all conditions. Samples with 0.5 wt% CS were more hydrophilic, although 0.1 wt% and 0.05 wt% samples absorbed the water droplet slower due to structure smaller pores. Mechanical analysis demonstrated that adding CS resulted in higher material stiffness compared to ePCL. However, with the increased CS concentration, the material became less stiff, decreasing YM and increasing TSB and EB.
References
[1] Sindhi K.et al, 2025, 10.1016/j.jtv.2025.100858
[2] Dias J.et al, 2017, 10.1016/j.eurpolymj.2017.08.015
[3] Syed M.et al, 2023, 10.1016/j.ijbiomac.2023.126735
Acknowledgment
This study was supported by the Fundação para a Ciência e a Tecnologia (FCT) through the Strategic Projects granted to CDRSP: UIDB/04044/2020; (doi.org/10.54499/UIDB/04044/2020), UIDP/04044/2020 (doi.org/10.54499/UIDP/04044/2020), to the Associate Laboratory ARISE (LA/P/0112/2020) and PTCentroDiH project (03/C16-i03/2022–768); the grant awarded to Sara F. C. Guerreiro (2021.05893.BD) and the funding to Juliana Dias (10.54499/CEECINST/00060/2021/CP2902/CT0005). This study was also supported by INOV.AM – Inovação em Fabricação Aditiva, 02-C05-i01.01-2022, Nanofilm (CENTRO2030-FEDER-01469100).
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