Silk‐Based antimicrobial polymers as a new platform to design drug‐free materials to impede microbial infections

Surgical site infections (SSI) represent a serious health problem that occur after invasive surgery, thus new antimicrobial biomaterials able to prevent SSI are needed. Silks are natural biopolymers with excellent biocompatibility, low immunogenicity and controllable biodegradability. Spider silkbased materials can be bioengineered and functionalized with specific peptides, such as antimicrobial peptides, creating innovative polymers. Herein, we explored new drugfree multifunctional silk films with antimicrobial properties, specifically tailored to hamper microbial infections. Different spider silk domains derived from the dragline sequence of the spider Nephila clavipes (6mer and 15mer, 27 and 41 kDa proteins, respectively) were fused with the two antimicrobial peptides, Hepcidin (Hep) and Human Neutrophil peptide 1 (HNP1). The selfassembly features of the spider silk domains (sheets) were maintained after functionalization. The bioengineered 6merHNP1 protein demonstrated inhibitory effects against microbial pathogens. Silkbased films with 6merHNP1 and different contents of silk fibroin (SF) significantly reduced bacterial adhesion and biofilm formation, whereas higher bacterial counts were found on the films prepared with 6mer or SF alone. The silkbased films showed no cytotoxic effects on human foreskin fibroblasts. The positive cellular response, together with structural and antimicrobial properties, highlight the potential of these multifunctional silkbased films as new materials for preventing SSI.The Portuguese Foundation for Science and Technology (FCT) under the project PTDC/BBB-BIO/0827/2012 and by the European Regional Development Fund (FEDER) through the "COMPETE" - Operational Programme for Competitiveness factors (FCOMP-01-0124-FEDER-028120) supported this work. The authors would like to thank Prof. Celia Manaia from the Escola Superior de Biotecnologia (Porto, Portugal) for providing the Pseudomonas sp. bacteria; and Dr. Alberta Faustino from the Hospital de S. Marcos (Braga, Portugal) for providing the other bacterial strains. A. R. Franco thanks FCT through the PostDoctoral scholarship SFRH/BPD/100760/2014.info:eu-repo/semantics/publishedVersio

Role of deep levels and interface states in the capacitance characteristics of all‐sputtered CuInSe2/CdS solar cell heterojunctions

All‐sputtered CuInSe2/CdS solar cellheterojunctions have been analyzed by means of capacitance‐frequency (C‐F) and capacitance‐bias voltage (C‐V) measurements. Depending on the CuInSe2 layer composition, two kinds of heterojunctions were analyzed: type 1 heterojunctions (based on stoichiometric or slightly In‐rich CuInSe2 layers) and type 2 heterojunctions (based on Cu‐rich CuInSe2 layers). In type 1 heterojunctions, a 80‐meV donor level has been found. Densities of interface states in the range 101 0–101 1 cm2 eV− 1 (type 1) and in the range 101 2–101 3 cm− 2 eV− 1 (type 2) have been deduced. On the other hand, doping concentrations of 1.6×101 6 cm− 3 for stoichiometric CuInSe2 (type 1 heterojunction) and 8×101 7 cm− 3 for the CdS (type 2 heterojunction) have been deduced from C‐Vmeasurements

Aspergillus niger: an unusual cause of invasive pulmonary aspergillosis

Infections due to Aspergillus species cause significant morbidity and mortality. Most are attributed to Aspergillus fumigatus, followed by Aspergillus flavus and Aspergillus terreus. Aspergillus niger is a mould that is rarely reported as a cause of pneumonia. A 72-year-old female with chronic obstructive pulmonary disease and temporal arteritis being treated with steroids long term presented with haemoptysis and pleuritic chest pain. Chest radiography revealed areas of heterogeneous consolidation with cavitation in the right upper lobe of the lung. Induced bacterial sputum cultures, and acid-fast smears and cultures were negative. Fungal sputum cultures grew A. niger. The patient clinically improved on a combination therapy of empiric antibacterials and voriconazole, followed by voriconazole monotherapy. After 4 weeks of voriconazole therapy, however, repeat chest computed tomography scanning showed a significant progression of the infection and near-complete necrosis of the right upper lobe of the lung. Serum voriconazole levels were low–normal (1.0 μg ml−1, normal range for the assay 0.5–6.0 μg ml−1). A. niger was again recovered from bronchoalveolar lavage specimens. A right upper lobectomy was performed, and lung tissue cultures grew A. niger. Furthermore, the lung histopathology showed acute and organizing pneumonia, fungal hyphae and oxalate crystallosis, confirming the diagnosis of invasive A. niger infection. A. niger, unlike A. fumigatus and A. flavus, is less commonly considered a cause of invasive aspergillosis (IA). The finding of calcium oxalate crystals in histopathology specimens is classic for A. niger infection and can be helpful in making a diagnosis even in the absence of conidia. Therapeutic drug monitoring may be useful in optimizing the treatment of IA given the wide variations in the oral bioavailability of voriconazole

Long-term antimicrobial activity of an ORMOSIL-containing orthodontic methacrylate resin: CFU

Poster Session - Dental Materials 9: Other Materials - Chemistry, Properties and Performance: abstract no. 663OBJECTIVES: To measure the effect of aging on antimicrobial activity of a novel, ORMOSIL-containing dental resin using measurement of colony forming units as the ass…link_to_OA_fulltex

Long-term antimicrobial activity of an ORMOSIL-containing orthodontic methacrylate resin: biomass

Poster Session - Dental Materials 9: Other Materials - Chemistry, Properties and Performance: abstract no. 662OBJECTIVES: To measure the aging effect on antimicrobial activity of a novel, ORMOSIL-containing dental resin using percent live microorganism count at the disk surface as the ass…link_to_OA_fulltex

Long-term antimicrobial activity of an ORMOSIL-containing orthodontic methacrylate resin: biomass

Poster Session - Dental Materials 9: Other Materials - Chemistry, Properties and Performance: abstract no. 662OBJECTIVES: To measure the aging effect on antimicrobial activity of a novel, ORMOSIL-containing dental resin using percent live microorganism count at the disk surface as the ass…link_to_OA_fulltex