Antifouling Zwitterionic Nanofibrous Wound Dressing for Long-Lasting Antibacterial Photodynamic Therapy

Nanofibrous mats as a wound dressing have received great attention in recent year. The development of biocompatible dressings with antibiofouling capability and long-lasting antibacterial properties is important but challenging. Antibacterial photodynamic therapy (aPDT) effectively eliminates pathogens via a photodynamic process that can circumvent the emergence of antibiotic-resistant pathogens. In this study, we integrated the zwitterionic materials (2-methacryloyloxyethyl phosphorylcholine (MPC) moiety) and aPDT photosensitizer, methylene blue (MB), to fabricate a long-lasting antibacterial nanofibrous mat using electrospinning technology. The prepared nanofibers possessed an appropriate water absorption and retention ability, superior cytocompatibility, and antibiofouling ability against both proteins and L929 cell adhesion. MB-loaded nanofibrous mats have exhibited superior aPDT against Gram-positive Staphylococcus aureus compared to Gram-negative Escherichia coli under moderate irradiation (100 W m–2) due to the presence of an extra outer membrane of Gram-negative bacteria serving as a protective barrier. In vitro release study demonstrated that the nanofibrous mat had a long-lasting drug release profile, which can efficiently suppress bacterial growth via aPDT. The antibacterial ability of the MB-loaded nanofibrous mat was commensurate or slightly inferior to antibiotics such as tetracycline and kanamycin, suggesting that it has the potential to be used as an antibiotic alternative. Overall, this zwitterionic nanofibrous mat with long-lasting aPDT function and nonadherent properties has potential as a promising antibacterial wound dressing

Reference of species

Reference of specie

Zwitterionic Core-Sheath Nanofibers in Antibacterial Photodynamic Therapy

Skin wounds and their related bacterial infections are one of the issues that would seriously threaten public health. Wound dressings affording antibiofouling capability and incorporating antimicrobial agents could prevent infection and favor wound healing, which have significant clinical demands and value. Antibacterial photodynamic therapy (aPDT) induces toxic singlet oxygen to kill microbes through a photodynamic pathway that avoid the development of drug-resistant microbes. In this study, coaxial electrospinning technology was employed to fabricate an antibacterial wound dressing containing thermoplastic polyurethane (TPU) as the core and zwitterionic and cross-linkable polysulfobetaine copolymer as the sheath. The prepared nanofibrous membranes exhibited good water uptake and retention capability, excellent in vitro biocompatibility and antifouling performance. The elastic properties of TPU improved the stretching and mechanical performance of the membranes that mimic the extensibility of the human skin. Moreover, methylene blue-loaded nanofibrous membranes have shown good antibacterial photodynamic inactivation against Gram-positiveStaphylococcus aureus (99.875%, 2.90 log units inactivation) and Gram-negative Escherichia coli (99.705%, 2.53 log units inactivation) upon mild light irradiation (500 W m–2), while as expected, E. coli cells have shown lower susceptibility to aPDT. Overall, the zwitterionic core-sheath nanofibrous membranes with aPDT function are potentially used as a promising antibacterial wound dressing

Trammel net sampling_Plant I

Trammel net sampling_Plant

Underwater visual census_Plant II

Underwater visual census_Plant I

Trammel net sampling_Plant II

Trammel net sampling_Plant I

A time series dataset of coastal fish community following a cold intrusion event in the Penghu Islands, Taiwan

Understanding variation of a community help establish useful mechanisms to mitigate the impacts of a disturbance. In late January and February 2008, there was a high mortality of fishes in the seas surrounding the coasts of the Penghu Islands in Taiwan due to an extreme low seawater temperature event. Here, we describe a time series dataset of fish communities at eight sampling stations along the coasts of the Penghu Islands using underwater diving visual censuses for seven years after the 2008 event. In total, 62 samples containing 24,278 individuals belonging to 277 species were recorded in the surveys. These data can provide information to ecologists and fisheries managers about how cold intrusion affected marine fishes and how much time the recovery of fishery resources is needed.<br

Underwater visual census_Plant I

Underwater visual census_Plant

README

READM

Additional file 1 of The effect of additional antimicrobial therapy on the outcomes of patients with idiopathic pulmonary fibrosis: a systematic review and meta-analysis

Additional file 1: PRISMA-2009-checklist_Wei