Aminolyzed Polycaprolactone Nanofiber Scaffolds with Visible Light-Activated Sterilization for Tissue Engineering Applications.

New photoactive nanofiber materials based on an aminolyzed polycaprolactone membrane with demonstrated cytocompatibility were developed. Two photoactive compounds, the photosensitizer Rose Bengal and the nitric oxide photodonor 4-nitro-3-(trifluoromethyl)aniline, were covalently bonded to the nanofiber surface, with or without a glutaraldehyde linker. The surface functionalization was confirmed via X-ray photoelectron spectroscopy, UV-vis absorption, and steady-state and time-resolved luminescence spectroscopy. Upon excitation with green or blue light, these materials efficiently generate antibacterial species, including singlet oxygen, with a slight contribution of hydrogen peroxide and nitric oxide. A potent light-induced antibacterial effect was demonstrated against Escherichia coli. Furthermore, the functionalized photoactive membranes, especially those with a glutaraldehyde linker and photosterilized by light, not only excluded the material toxicity but also demonstrated improved cell adhesion and proliferation when tested with adipose tissue-derived stem cells. These materials, which offer a unique combination of light-controlled surface sterilization and high cellular compatibility, are promising for advanced tissue engineering applications.