Electrospun Methacrylated Gelatin/Poly(L-Lactic Acid) Nanofibrous Hydrogel Scaffolds for Potential Wound Dressing Application

Abstract

Electrospun nanofiber mats have attracted intense attention as advanced wound dressing materials. The objective of this study was to fabricate methacrylated gelatin (MeGel)/poly(L-lactic acid) (PLLA) hybrid nanofiber mats with an extracellular matrix (ECM) mimicking nanofibrous structure and hydrogel-like properties for potential use as wound dressing materials. MeGel was first synthesized via the methacryloyl substitution of gelatin (Gel), a series of MeGel and PLLA blends with various mass ratios were electrospun into nanofiber mats, and a UV crosslinking process was subsequently utilized to stabilize the MeGel components in the nanofibers. All the as-crosslinked nanofiber mats exhibited smooth and bead-free fiber morphologies. The MeGel-containing and crosslinked nanofiber mats presented significantly improved hydrophilic properties (water contact angle = 0°; 100% wettability) compared to the pure PLLA nanofiber mats (~127°). The swelling ratio of crosslinked nanofiber mats notably increased with the increase of MeGel (143.6 ± 7.4% for PLLA mats vs. 875.0 ± 17.1% for crosslinked 1:1 MeGel/PLLA mats vs. 1135.2 ± 16.0% for crosslinked MeGel mats). The UV crosslinking process was demonstrated to significantly improve the structural stability and mechanical properties of MeGel/PLLA nanofiber mats. The Young’s modulus and ultimate strength of the crosslinked nanofiber mats were demonstrated to obviously decrease when more MeGel was introduced in both dry and wet conditions. The biological tests showed that all the crosslinked nanofiber mats presented great biocompatibility, but the crosslinked nanofiber mats with more MeGel were able to notably promote the attachment, growth, and proliferation of human dermal fibroblasts. Overall, this study demonstrates that our MeGel/PLLA blend nanofiber mats are attractive candidates for wound dressing material research and application.

State-of-the-Art Review of Electrospun Gelatin-Based Nanofiber Dressings for Wound Healing Applications

“…Although electrospun nanofibers made of pure gelatin have been successfully produced based on numerous different spinning solvents, the gelatin macromolecules in electrospun nanofibers commonly possess random coil conformation, inevitable resulting in inferior water-resistant capacity and poor mechanical properties. The previous studies demonstrated that the electrospun nanofibers made of pure gelatin may dissolve immediately once contacted with water [ 75 , 76 ]. To address these issues, lots of different physical or chemical crosslinking strategies have been developed to process the as-fabricated electrospun gelatin nanofibers [ 77 , 78 ].…”

“…The final generated nanofiber mats had increased structural stability and great water uptaking capacity. Sun et al synthesized methacrylated gelatin (MeGel) through a methacryloyl substitution of gelatin ( Figure 4 B) [ 76 ]. The synthesized MeGel was blended with PLLA for electrospinning, and a subsequent UV crosslinking process was used to stabilize the MeGel component of MeGel/PLLA nanofiber mats ( Figure 4 C).…”

“…( A ) Reprinted with permission from ref [ 122 ], ACS Publications, 2013. ( B , C ) Reprinted with permission from ref [ 76 ], MDPI, 2022.…”

Current and advanced therapies for chronic wound infection

“…Nanomedicines also seem to aid healing through molecular and cellular pathways [75]. For example, a methacrylated gelatin (MeGel)/poly(L-lactic acid) hybrid nanofiber synthesised has been reported to stimulate the recruitment and proliferation of human dermal fibroblasts, thereby promoting wound healing [76]. Nanoparticles can not only act as carriers of antimicrobial agents, they can also have an intrinsic antimicrobial effect [75,77,78].…”

Electrospun Chitosan–Polyvinyl Alcohol Nanofiber Dressings Loaded with Bioactive Ursolic Acid Promoting Diabetic Wound Healing

“…Unfortunately, there are still no ideal strategies for the scarless regeneration and full recovery of diabetic wound in clinics [ 7 ]. The design and development of advanced dressing materials with multiple functions seem to be a promising strategy to address this intractable issue [ 8 ].…”