Melt Electrowriting of Polyhydroxyalkanoates for Enzymatically Degradable Scaffolds

Melt electrowriting (MEW) enables precise scaffold fabrication for biomedical applications. With a limited number of processable materials with short and tunable degradation times, polyhydroxyalkanoates (PHAs) present an interesting option. Here, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and a blend of PHBV and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (PHBV+P34HB) are successfully melt electrowritten into scaffolds with various architectures. PHBV+P34HB exhibits greater thermal stability, making it a superior printing material compared to PHBV in MEW. The PHBV+P34HB scaffolds subjected to enzymatic degradation show tunable degradation times, governed by enzyme dilution, incubation time, and scaffold surface area. PHBV+P34HB scaffolds seeded with human dermal fibroblasts (HDFs), demonstrate enhanced cell adherence, proliferation, and spreading. The HDFs, when exposed to the enzyme solutions and enzymatic degradation residues, show good viability and proliferation rates. Additionally, HDFs grown on enzymatically pre-incubated scaffolds do not show any difference in behavior compared those grown on control scaffolds. It is concluded that PHAs, as biobased materials with enzymatically tunable degradability rates, are an important addition to the already limited set of materials available for MEW technology.