Preparation and characterization of peptide-modified core-shell fibrous substrates with UV-blocking properties for corneal regeneration applications

• Application of peptides based on tryptophan, tyrosine and cysteine improves UV barrier properties through increased UV absorption (up to 80 % UVB and 40 % UVA) and antioxidant activity (>79 % for cysteine-based peptides). • UV irradiation increase the surface zeta potential of core–shell fibers (from −20 mV to −2mV) and stabilise thermal properties (stable Tm), indicating PVP crosslinking. • Presence of the hydrogel layer decrease the contact angle (from 134° to 55°) and thus, increase the light transmission (from 50% to 90%) through the nonwoven comparing to the pure PCL nonwoven. • The impact of UVR on the material should be considered in design process of the ophthalmology implants (i.e. cornea) exposed to solar radiation. Effective UV protection is a key aspect of substrates directly exposed to UV radiation. Therefore, in the present study, fibrous substrates of core–shell morphology (PCL-core, PVP-shell) containing peptides based on tryptophan, tyrosine and cysteine (W6, YYC2 and YYC3) were prepared. Spectrophotometric studies showed UV absorption by peptides containing tyrosine and tryptophan in the UVB (up to 80%) and UVA (up to 40%) ranges. Cysteine, in turn, contributed to high antioxidant properties, confirmed by DPPH assay. The presence of peptides contributed to a nonwoven fabric characterized by the ability to absorb UV radiation and prevent the occurrence of oxidative stress (caused by the presence of free radicals). In turn, the increase in the surface zeta potential of the nonwoven after UV irradiation and higher thermal stability (demonstrated by DSC studies) indicated the crosslinking of the PVP layer under UVR, which further contributes to the increased protection of the nonwoven against its effects. In summary, obtained nonwoven exhibited functional similarity to the native cornea, providing a potential solution for enhancing corneal tissue engineering and regenerative medicine applications.