Ogically active species [12,13], and as Title Loaded From File antimicrobial agents [14,15]. Recent studies have described the photobactericidal properties of polyurethane, polystyrene and polycaprolactone nanofiber materials loaded with porphyrinoid photosensitizers [16,17,18]. These nanofibers generate O2(1Dg) and are promising materials for use in the preparation of self-disinfecting wound dressings or filters for water treatment. In contrast to standard anti-bacterial agents, for which continuous release from matrices can lead 25033180 to diminishingeffectiveness over time, these nanofiber materials use atmospheric oxygen and are therefore effective for longer time periods. In this study, we selected two medical-grade nanofiber materials, polyurethane TecophilicH and polycaprolactone (PCL), and loaded them with the photosensitizer 5,10,15,20tetraphenylporphyrin (TPP), which generates O2(1Dg) with a high quantum yield (WD = 0.62) upon irradiation [19]. These materials degrade into nontoxic products under physiological conditions, and they are capable of absorbing water, which is essential for optimal wound healing [20]. The previously reported strong photobactericidal effect of O2(1Dg)-producing nanofiber materials [16,17] led us to test a similar approach for the photoinactivation of viruses. We used polyomaviruses as models for non-enveloped viruses and baculoviruses as models for enveloped viruses. The capsid proteins of non-enveloped viruses and the envelope glycoproteins encoded by enveloped viruses enable the viruses to cross plasma membranes into cells and deliver their genetic material to the cell nucleus (or other cellular compartments), resulting in viral gene expression. These proteins are responsible for cell surface receptor recognition and for subsequent interactions with cellular structures, leading to the disassembly of virus particles and the release of genetic information. Therefore, oxidative damage to virion surface proteins via photooxidation of readily oxidizable amino acids (Trp, His, Met and Cys) by O2(1Dg) may be an effective way to prevent infection [21,22]. Polyomaviruses, small tumorogenic non-enveloped DNA viruses, have a wide range of hosts, including humans. Two human polyomaviruses, JCV and BKV, which were discovered in 1971, cause Title Loaded From File progressive multifocal leukoencephalopathy and nephropa-Virucidal Nanofiber Textilesthy, respectively, in immunosuppressed patients [23,24]. Since 2007, six new human polyomaviruses (the KI and WU polyomaviruses, Merkel cell polyomavirus, Trichodysplasia spinulosa virus, polyomavirus 6 and polyomavirus 7) have been identified [25,26,27]. Merkel cell polyomavirus (MCV or MCPyV), which was described in 2008, is suspected to cause the majority of the cases of Merkel cell carcinoma, a rare but aggressive form of human skin cancer. Baculoviruses, which are large enveloped DNA viruses, are insect pathogens that have been widely used to produce recombinant proteins in cultured insect cells. Baculovirus envelope proteins are also able to mediate entry into human and other mammalian cells and, thus, facilitate the expression of recombinant genes under the transcriptional control of a mammalian promoter. The Autographa californica multiple nuclear polyhedrosis virus (AcMNPV), which was used in our experiments, enters cells via a low pH-dependent endocytic pathway [28]. During endocytosis, the major envelope glycoprotein GP64 mediates low pH-triggered membrane fusion, thus releasing nucleocapsids to allow trafficking.Ogically active species [12,13], and as antimicrobial agents [14,15]. Recent studies have described the photobactericidal properties of polyurethane, polystyrene and polycaprolactone nanofiber materials loaded with porphyrinoid photosensitizers [16,17,18]. These nanofibers generate O2(1Dg) and are promising materials for use in the preparation of self-disinfecting wound dressings or filters for water treatment. In contrast to standard anti-bacterial agents, for which continuous release from matrices can lead 25033180 to diminishingeffectiveness over time, these nanofiber materials use atmospheric oxygen and are therefore effective for longer time periods. In this study, we selected two medical-grade nanofiber materials, polyurethane TecophilicH and polycaprolactone (PCL), and loaded them with the photosensitizer 5,10,15,20tetraphenylporphyrin (TPP), which generates O2(1Dg) with a high quantum yield (WD = 0.62) upon irradiation [19]. These materials degrade into nontoxic products under physiological conditions, and they are capable of absorbing water, which is essential for optimal wound healing [20]. The previously reported strong photobactericidal effect of O2(1Dg)-producing nanofiber materials [16,17] led us to test a similar approach for the photoinactivation of viruses. We used polyomaviruses as models for non-enveloped viruses and baculoviruses as models for enveloped viruses. The capsid proteins of non-enveloped viruses and the envelope glycoproteins encoded by enveloped viruses enable the viruses to cross plasma membranes into cells and deliver their genetic material to the cell nucleus (or other cellular compartments), resulting in viral gene expression. These proteins are responsible for cell surface receptor recognition and for subsequent interactions with cellular structures, leading to the disassembly of virus particles and the release of genetic information. Therefore, oxidative damage to virion surface proteins via photooxidation of readily oxidizable amino acids (Trp, His, Met and Cys) by O2(1Dg) may be an effective way to prevent infection [21,22]. Polyomaviruses, small tumorogenic non-enveloped DNA viruses, have a wide range of hosts, including humans. Two human polyomaviruses, JCV and BKV, which were discovered in 1971, cause progressive multifocal leukoencephalopathy and nephropa-Virucidal Nanofiber Textilesthy, respectively, in immunosuppressed patients [23,24]. Since 2007, six new human polyomaviruses (the KI and WU polyomaviruses, Merkel cell polyomavirus, Trichodysplasia spinulosa virus, polyomavirus 6 and polyomavirus 7) have been identified [25,26,27]. Merkel cell polyomavirus (MCV or MCPyV), which was described in 2008, is suspected to cause the majority of the cases of Merkel cell carcinoma, a rare but aggressive form of human skin cancer. Baculoviruses, which are large enveloped DNA viruses, are insect pathogens that have been widely used to produce recombinant proteins in cultured insect cells. Baculovirus envelope proteins are also able to mediate entry into human and other mammalian cells and, thus, facilitate the expression of recombinant genes under the transcriptional control of a mammalian promoter. The Autographa californica multiple nuclear polyhedrosis virus (AcMNPV), which was used in our experiments, enters cells via a low pH-dependent endocytic pathway [28]. During endocytosis, the major envelope glycoprotein GP64 mediates low pH-triggered membrane fusion, thus releasing nucleocapsids to allow trafficking.
