Healing of skin wounds as caused by acute trauma, burns and surgical procedures depends on an intricate interplay between cellular factors and surrounding extracellular matrix (ECM). Tissue engineering strategies seek to accelerate wound healing by providing the wound bed with an artificial matrix like electrospun mats with ECM-like nanofibrous architecture. However, the nanoporous structures of these scaffolds limit three-dimensional (3D) cell infiltration into the scaffolds, while enlarged pore size of the fibrous scaffolds for cell infiltration may compromise the mechanical properties and dimensional stability of the scaffolds. To address this, electrospun nanofibers with tuneable physical properties without changing the pore dimensions have been studied for better cell infiltration. However, the existing electrospun fibers are commonly made of synthetic polymers which usually lack cell-recognition signals and render them less ideal for skin regeneration applications. Therefore, development of natural polymer-based fibrous scaffolds with tunable physical and biological properties is highly desirable to construct a 3D, fully cellularized scaffold for wound healing.

Recently, Dr. Xin Zhao from Bioinspired Engineering and Biomechanics Center at Xi'an Jiaotong University in collaboration with Prof. Ali Khademhosseini from Harvard University have developed 3D electrospun hydrogel fibrous scaffolds with soft elasticity made of photo-crosslinkable gelatin (GelMA), which were found to be able to support cell infiltration and accelerate wound healing. GelMA, modified from natural polymer gelatin with methacrylates, has tunable physical and biological properties. By changing the light exposure time, i.e., the crosslinking density of the GelMA hydrogel fibers, the GelMA hydrogel fibrous scaffolds can be varied to be soft and elastic, supporting cell adhesion, proliferation and migration into the whole scaffolds and accelerating skin regeneration. Such tunable properties have enabled the GelMA hydrogel fibrous scaffolds to accommodate different patients’ needs, which is in stark contrast with the conventionally used electrospun gelatin or poly (lactic-co-glycolic acid) scaffolds whose physical properties cannot be readily tuned. It is envisioned that the GelMA hydrogel fibrous scaffolds have great clinical potential for skin regeneration. Details of this work can be obtained from Acta Biomaterialia (DOI: http://dx.doi.org/10.1016/j.actbio.2016.11.017).