Enhanced Antibacterial Activity through Silver Nanoparticles Deposited onto Carboxylated Graphene Oxide Surface

[EN] The strong bactericidal action of silver nanoparticles (AgNPs) is usually limited by their degree of aggregation. Deposition of AgNPs onto a graphene oxide (GO) surface to generate GO-Ag hybrids has been shown to be an effective method of controlling these aggregation problems. In this sense, a novel carboxylated graphene oxide-silver nanoparticle (GOCOOH-Ag) material has been synthesized, and their antibacterial and biofilm formation inhibitions have been studied. AgNPs decorating the GOCOOH surface achieved an average size of 6.74 +/- 0.25 nm, which was smaller than that of AgNPs deposited onto the GO surface. In addition, better distribution of AgNPs was achieved using carboxylated material. It is important to highlight the main role of the carboxylic groups in the nucleation and growth of the AgNPs that decorate the GO-based material surface. In vitro antibacterial activity and antibiofilm-forming action were tested against Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli). Both GO-Ag and GOCOOH-Ag reduced bacterial growth, analyzed by time-kill curves. However, the minimum inhibitory concentration and the minimum bactericidal concentration of GOCOOH-Ag were lower than those of GO-Ag for all strains studied, indicating that GOCOOH-Ag has better antibacterial activity. In addition, both nanomaterials prevent biofilm formation, with a higher reduction of biofilm mass and cell viability in the presence of GOCOOH-Ag. The carboxylation functionalization in GO-based materials can be applied to improve the bactericidal and antibiofilm-forming action of the AgNPs.This research was funded by Agencia Valenciana de la Innovacio (Valencian Regional Government) under the project INNEST00/19/002 and the Spanish Ministerio de Economia, Industria y Competitividad (project SAF2017-82251-R) and co-financed with ERDF (European Regional Development Fund) "A way for Europe".Barjola, A.; Tormo-Mas, MÁ.; Sahuquillo, O.; Bernabé-Quispe, P.; Pérez, JM.; Giménez Torres, E. (2022). Enhanced Antibacterial Activity through Silver Nanoparticles Deposited onto Carboxylated Graphene Oxide Surface. Nanomaterials. 12(12):1-15. https://doi.org/10.3390/nano12121949115121

Antibacterial Activity of Linezolid against Gram-Negative Bacteria: Utilization of E-Poly-l-Lysine Capped Silica Xerogel as an Activating Carrier

[EN] In recent times, many approaches have been developed against drug resistant Gram-negative bacteria. However, low-cost high effective materials which could broaden the spectrum of antibiotics are still needed. In this study, enhancement of linezolid spectrum, normally active against Gram-positive bacteria, was aimed for Gram-negative bacteria growth inhibition. For this purpose, a silica xerogel prepared from a low-cost precursor is used as a drug carrier owing to the advantages of its mesoporous structure, suitable pore and particle size and ultralow density. The silica xerogel is loaded with linezolid and capped with epsilon-poly-l-lysine. The developed nano-formulation shows a marked antibacterial activity against to Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. In comparison to free linezolid and epsilon-poly-l-lysine, the material demonstrates a synergistic effect on killing for the three tested bacteria. The results show that silica xerogels can be used as a potential drug carrier and activity enhancer. This strategy could provide the improvement of antibacterial activity spectrum of antibacterial agents like linezolid and could represent a powerful alternative to overcome antibiotic resistance in a near future.We thank the Spanish Government (projects RTI2018-100910-B-C41, RTI2018-101599-B-C22-AR and SAF2017-82251-R (MCUI/AEI/FEDER, UE)) and the Generalitat Valenciana (project PROMETEO/2018/024) for support. G.G.K. would like to thank Academic Staff Training Program (2016-OYP-071) and TUBITAK for 2214-A International Research Fellowship Program for PhD Students. S.M. thanks Generalitat Valenciana for her Santiago Grisolia fellowship. V.C.-N. thanks Spanish Ministerio de Educacion for his FPU grant (FPU15/02753).Guzel Kaya, G.; Medaglia, S.; Candela-Noguera, V.; Tormo-Mas, MÁ.; Marcos Martínez, MD.; Aznar, E.; Deveci, H.... (2020). Antibacterial Activity of Linezolid against Gram-Negative Bacteria: Utilization of E-Poly-l-Lysine Capped Silica Xerogel as an Activating Carrier. Pharmaceutics. 12(11):1-14. https://doi.org/10.3390/pharmaceutics12111126S1141211Hammad, A., Abutaleb, N. S., Elsebaei, M. M., Norvil, A. B., Alswah, M., Ali, A. O., … Mayhoub, A. S. (2019). From Phenylthiazoles to Phenylpyrazoles: Broadening the Antibacterial Spectrum toward Carbapenem-Resistant Bacteria. Journal of Medicinal Chemistry, 62(17), 7998-8010. doi:10.1021/acs.jmedchem.9b00720Yarlagadda, V., Manjunath, G. B., Sarkar, P., Akkapeddi, P., Paramanandham, K., Shome, B. R., … Haldar, J. (2015). Glycopeptide Antibiotic To Overcome the Intrinsic Resistance of Gram-Negative Bacteria. ACS Infectious Diseases, 2(2), 132-139. doi:10.1021/acsinfecdis.5b00114Serri, A., Mahboubi, A., Zarghi, A., & Moghimi, H. R. (2018). PAMAM-dendrimer Enhanced Antibacterial Effect of Vancomycin Hydrochloride Against Gram-Negative Bacteria. Journal of Pharmacy & Pharmaceutical Sciences, 22, 10-21. doi:10.18433/jpps29659Bernardos, A., Piacenza, E., Sancenón, F., Hamidi, M., Maleki, A., Turner, R. J., & Martínez‐Máñez, R. (2019). Mesoporous Silica‐Based Materials with Bactericidal Properties. Small, 15(24), 1900669. doi:10.1002/smll.201900669Rai, M., Ingle, A. P., Pandit, R., Paralikar, P., Gupta, I., Chaud, M. V., & dos Santos, C. A. (2017). Broadening the spectrum of small-molecule antibacterials by metallic nanoparticles to overcome microbial resistance. International Journal of Pharmaceutics, 532(1), 139-148. doi:10.1016/j.ijpharm.2017.08.127Nicolosi, D., Scalia, M., Nicolosi, V. M., & Pignatello, R. (2010). Encapsulation in fusogenic liposomes broadens the spectrum of action of vancomycin against Gram-negative bacteria. International Journal of Antimicrobial Agents, 35(6), 553-558. doi:10.1016/j.ijantimicag.2010.01.015Cottarel, G., & Wierzbowski, J. (2007). Combination drugs, an emerging option for antibacterial therapy. Trends in Biotechnology, 25(12), 547-555. doi:10.1016/j.tibtech.2007.09.004Ulubayram, K., Calamak, S., Shahbazi, R., & Eroglu, I. (2015). Nanofibers Based Antibacterial Drug Design, Delivery and Applications. Current Pharmaceutical Design, 21(15), 1930-1943. doi:10.2174/1381612821666150302151804Chen, C., & Yang, K. (2019). Ebselen bearing polar functionality: Identification of potent antibacterial agents against multidrug-resistant Gram-negative bacteria. Bioorganic Chemistry, 93, 103286. doi:10.1016/j.bioorg.2019.103286Mas, N., Galiana, I., Mondragón, L., Aznar, E., Climent, E., Cabedo, N., … Amorós, P. (2013). Enhanced Efficacy and Broadening of Antibacterial Action of Drugs via the Use of Capped Mesoporous Nanoparticles. Chemistry - A European Journal, 19(34), 11167-11171. doi:10.1002/chem.201302170Sperandio, F., Huang, Y.-Y., & Hamblin, M. (2013). Antimicrobial Photodynamic Therapy to Kill Gram-negative Bacteria. Recent Patents on Anti-Infective Drug Discovery, 8(2), 108-120. doi:10.2174/1574891x113089990012Velikova, N., Mas, N., Miguel-Romero, L., Polo, L., Stolte, E., Zaccaria, E., … Wells, J. (2017). Broadening the antibacterial spectrum of histidine kinase autophosphorylation inhibitors via the use of ε-poly-L-lysine capped mesoporous silica-based nanoparticles. Nanomedicine: Nanotechnology, Biology and Medicine, 13(2), 569-581. doi:10.1016/j.nano.2016.09.011Hernández Montoto, A., Montes, R., Samadi, A., Gorbe, M., Terrés, J. M., Cao-Milán, R., … Martínez-Máñez, R. (2018). Gold Nanostars Coated with Mesoporous Silica Are Effective and Nontoxic Photothermal Agents Capable of Gate Keeping and Laser-Induced Drug Release. ACS Applied Materials & Interfaces, 10(33), 27644-27656. doi:10.1021/acsami.8b08395García‐Fernández, A., Aznar, E., Martínez‐Máñez, R., & Sancenón, F. (2019). New Advances in In Vivo Applications of Gated Mesoporous Silica as Drug Delivery Nanocarriers. Small, 16(3), 1902242. doi:10.1002/smll.201902242Giménez, C., de la Torre, C., Gorbe, M., Aznar, E., Sancenón, F., Murguía, J. R., … Amorós, P. (2015). Gated Mesoporous Silica Nanoparticles for the Controlled Delivery of Drugs in Cancer Cells. Langmuir, 31(12), 3753-3762. doi:10.1021/acs.langmuir.5b00139Moreno, V. M., Álvarez, E., Izquierdo‐Barba, I., Baeza, A., Serrano‐López, J., & Vallet‐Regí, M. (2020). Bacteria as Nanoparticles Carrier for Enhancing Penetration in a Tumoral Matrix Model. Advanced Materials Interfaces, 7(11), 1901942. doi:10.1002/admi.201901942Shadjou, N., & Hasanzadeh, M. (2015). Bone tissue engineering using silica-based mesoporous nanobiomaterials:Recent progress. Materials Science and Engineering: C, 55, 401-409. doi:10.1016/j.msec.2015.05.027Mas, N., Arcos, D., Polo, L., Aznar, E., Sánchez-Salcedo, S., Sancenón, F., … Martínez-Máñez, R. (2014). Towards the Development of Smart 3D «Gated Scaffolds» for On-Command Delivery. Small, 10(23), 4859-4864. doi:10.1002/smll.201401227Wang, Y., Zhao, Q., Han, N., Bai, L., Li, J., Liu, J., … Wang, S. (2015). Mesoporous silica nanoparticles in drug delivery and biomedical applications. Nanomedicine: Nanotechnology, Biology and Medicine, 11(2), 313-327. doi:10.1016/j.nano.2014.09.014Llopis-Lorente, A., Díez, P., Sánchez, A., Marcos, M. D., Sancenón, F., Martínez-Ruiz, P., … Martínez-Máñez, R. (2017). Interactive models of communication at the nanoscale using nanoparticles that talk to one another. Nature Communications, 8(1). doi:10.1038/ncomms15511Giménez, C., Climent, E., Aznar, E., Martínez-Máñez, R., Sancenón, F., Marcos, M. D., … Rurack, K. (2014). Towards Chemical Communication between Gated Nanoparticles. Angewandte Chemie International Edition, n/a-n/a. doi:10.1002/anie.201405580Luis, B., Llopis‐Lorente, A., Rincón, P., Gadea, J., Sancenón, F., Aznar, E., … Martínez‐Máñez, R. (2019). An Interactive Model of Communication between Abiotic Nanodevices and Microorganisms. Angewandte Chemie International Edition, 58(42), 14986-14990. doi:10.1002/anie.201908867Hasanzadeh, M., Shadjou, N., de la Guardia, M., Eskandani, M., & Sheikhzadeh, P. (2012). Mesoporous silica-based materials for use in biosensors. TrAC Trends in Analytical Chemistry, 33, 117-129. doi:10.1016/j.trac.2011.10.011El-Safty, S. A., & Shenashen, M. A. (2020). Nanoscale dynamic chemical, biological sensor material designs for control monitoring and early detection of advanced diseases. Materials Today Bio, 5, 100044. doi:10.1016/j.mtbio.2020.100044Pla, L., Santiago-Felipe, S., Tormo-Mas, M. Á., Pemán, J., Sancenón, F., Aznar, E., & Martínez-Máñez, R. (2020). Aptamer-Capped nanoporous anodic alumina for Staphylococcus aureus detection. Sensors and Actuators B: Chemical, 320, 128281. doi:10.1016/j.snb.2020.128281Ciriminna, R., Fidalgo, A., Pandarus, V., Béland, F., Ilharco, L. M., & Pagliaro, M. (2013). The Sol–Gel Route to Advanced Silica-Based Materials and Recent Applications. Chemical Reviews, 113(8), 6592-6620. doi:10.1021/cr300399cUlker, Z., & Erkey, C. (2014). An emerging platform for drug delivery: Aerogel based systems. Journal of Controlled Release, 177, 51-63. doi:10.1016/j.jconrel.2013.12.033Guzel Kaya, G., Yilmaz, E., & Deveci, H. (2018). Sustainable nanocomposites of epoxy and silica xerogel synthesized from corn stalk ash: Enhanced thermal and acoustic insulation performance. Composites Part B: Engineering, 150, 1-6. doi:10.1016/j.compositesb.2018.05.039Maleki, H., Durães, L., García-González, C. A., del Gaudio, P., Portugal, A., & Mahmoudi, M. (2016). Synthesis and biomedical applications of aerogels: Possibilities and challenges. Advances in Colloid and Interface Science, 236, 1-27. doi:10.1016/j.cis.2016.05.011Quintanar-Guerrero, D., Ganem-Quintanar, A., Nava-Arzaluz, M. G., & Piñón-Segundo, E. (2009). Silica xerogels as pharmaceutical drug carriers. Expert Opinion on Drug Delivery, 6(5), 485-498. doi:10.1517/17425240902902307Pérez, N. A., Lima, E., Bosch, P., & Méndez-Vivar, J. (2014). Consolidating materials for the volcanic tuff in western Mexico. Journal of Cultural Heritage, 15(4), 352-358. doi:10.1016/j.culher.2013.07.010Lemougna, P. N., Wang, K., Tang, Q., Nzeukou, A. N., Billong, N., Melo, U. C., & Cui, X. (2018). Review on the use of volcanic ashes for engineering applications. Resources, Conservation and Recycling, 137, 177-190. doi:10.1016/j.resconrec.2018.05.031Marañón, E., Ulmanu, M., Fernández, Y., Anger, I., & Castrillón, L. (2006). Removal of ammonium from aqueous solutions with volcanic tuff. Journal of Hazardous Materials, 137(3), 1402-1409. doi:10.1016/j.jhazmat.2006.03.069Brum, L. F. W., Santos, C. dos, Gnoatto, J. A., Moura, D. J., Santos, J. H. Z., & Brandelli, A. (2019). Silica xerogels as novel streptomycin delivery platforms. Journal of Drug Delivery Science and Technology, 53, 101210. doi:10.1016/j.jddst.2019.101210Deon, M., Morawski, F. M., Passaia, C., Dalmás, M., Laranja, D. C., Malheiros, P. S., … Benvenutti, E. V. (2018). Chitosan-stabilized gold nanoparticles supported on silica/titania magnetic xerogel applied as antibacterial system. Journal of Sol-Gel Science and Technology, 89(1), 333-342. doi:10.1007/s10971-018-4699-6Storm, W. L., Youn, J., Reighard, K. P., Worley, B. V., Lodaya, H. M., Shin, J. H., & Schoenfisch, M. H. (2014). Superhydrophobic nitric oxide-releasing xerogels. Acta Biomaterialia, 10(8), 3442-3448. doi:10.1016/j.actbio.2014.04.029Guzel Kaya, G., Yilmaz, E., & Deveci, H. (2019). A novel silica xerogel synthesized from volcanic tuff as an adsorbent for high‐efficient removal of methylene blue: parameter optimization using Taguchi experimental design. Journal of Chemical Technology & Biotechnology, 94(8), 2729-2737. doi:10.1002/jctb.6089Mohammadian, M., Jafarzadeh Kashi, T. S., Erfan, M., & Soorbaghi, F. P. (2018). Synthesis and characterization of silica aerogel as a promising drug carrier system. Journal of Drug Delivery Science and Technology, 44, 205-212. doi:10.1016/j.jddst.2017.12.017Hu, W., Li, M., Chen, W., Zhang, N., Li, B., Wang, M., & Zhao, Z. (2016). Preparation of hydrophobic silica aerogel with kaolin dried at ambient pressure. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 501, 83-91. doi:10.1016/j.colsurfa.2016.04.059Zhu, H., Jia, S., Yang, H., Tang, W., Jia, Y., & Tan, Z. (2010). Characterization of bacteriostatic sausage casing: A composite of bacterial cellulose embedded with ɛ-polylysine. Food Science and Biotechnology, 19(6), 1479-1484. doi:10.1007/s10068-010-0211-yLei, Y., Hu, Z., Cao, B., Chen, X., & Song, H. (2017). Enhancements of thermal insulation and mechanical property of silica aerogel monoliths by mixing graphene oxide. Materials Chemistry and Physics, 187, 183-190. doi:10.1016/j.matchemphys.2016.11.064Huang, D., Guo, C., Zhang, M., & Shi, L. (2017). Characteristics of nanoporous silica aerogel under high temperature from 950 °C to 1200 °C. Materials & Design, 129, 82-90. doi:10.1016/j.matdes.2017.05.024Shi, K., Liu, Y., Ke, L., Fang, Y., Yang, R., & Cui, F. (2015). Epsilon-poly-l-lysine guided improving pulmonary delivery of supramolecular self-assembled insulin nanospheres. International Journal of Biological Macromolecules, 72, 1441-1450. doi:10.1016/j.ijbiomac.2014.10.023Lin, L., Xue, L., Duraiarasan, S., & Haiying, C. (2018). Preparation of ε-polylysine/chitosan nanofibers for food packaging against Salmonella on chicken. Food Packaging and Shelf Life, 17, 134-141. doi:10.1016/j.fpsl.2018.06.013Lv, J., Meng, Y., Shi, Y., Li, Y., Chen, J., & Sheng, F. (2019). Properties of epsilon‐polylysine·HCl/high‐methoxyl pectin polyelectrolyte complexes and their commercial application. Journal of Food Processing and Preservation, 44(2). doi:10.1111/jfpp.14320Huber, L., Zhao, S., Malfait, W. J., Vares, S., & Koebel, M. M. (2017). Fast and Minimal-Solvent Production of Superinsulating Silica Aerogel Granulate. Angewandte Chemie International Edition, 56(17), 4753-4756. doi:10.1002/anie.201700836Shi, F., Liu, J.-X., Song, K., & Wang, Z.-Y. (2010). Cost-effective synthesis of silica aerogels from fly ash via ambient pressure drying. Journal of Non-Crystalline Solids, 356(43), 2241-2246. doi:10.1016/j.jnoncrysol.2010.08.005Sarawade, P. B., Kim, J.-K., Hilonga, A., & Kim, H. T. (2010). Production of low-density sodium silicate-based hydrophobic silica aerogel beads by a novel fast gelation process and ambient pressure drying process. Solid State Sciences, 12(5), 911-918. doi:10.1016/j.solidstatesciences.2010.01.032Liu, G., Yang, R., & Li, M. (2010). Liquid adsorption of basic dye using silica aerogels with different textural properties. Journal of Non-Crystalline Solids, 356(4-5), 250-257. doi:10.1016/j.jnoncrysol.2009.11.019Guzel Kaya, G., & Deveci, H. (2020). Effect of Aging Solvents on Physicochemical and Thermal Properties of Silica Xerogels Derived from Steel Slag. ChemistrySelect, 5(4), 1586-1591. doi:10.1002/slct.201903345Rao, A. P., Rao, A. V., & Gurav, J. L. (2007). Effect of protic solvents on the physical properties of the ambient pressure dried hydrophobic silica aerogels using sodium silicate precursor. Journal of Porous Materials, 15(5), 507-512. doi:10.1007/s10934-007-9104-8Sperling, R. A., & Parak, W. J. (2010). Surface modification, functionalization and bioconjugation of colloidal inorganic nanoparticles. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 368(1915), 1333-1383. doi:10.1098/rsta.2009.0273Ma, X., Lee, N.-H., Oh, H.-J., Kim, J.-W., Rhee, C.-K., Park, K.-S., & Kim, S.-J. (2010). Surface modification and characterization of highly dispersed silica nanoparticles by a cationic surfactant. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 358(1-3), 172-176. doi:10.1016/j.colsurfa.2010.01.051Tan, L., Tan, X., Fang, M., Yu, Z., & Wang, X. (2018). Effects of humic acid and Mg2+ on morphology and aggregation behavior of silica aerogels. Journal of Molecular Liquids, 264, 261-268. doi:10.1016/j.molliq.2018.05.064Wang, L., Hu, C., & Shao, L. (2017). The antimicrobial activity of nanoparticles: present situation and prospects for the future. International Journal of Nanomedicine, Volume 12, 1227-1249. doi:10.2147/ijn.s121956Hasan, J., Crawford, R. J., & Ivanova, E. P. (2013). Antibacterial surfaces: the quest for a new generation of biomaterials. Trends in Biotechnology, 31(5), 295-304. doi:10.1016/j.tibtech.2013.01.017Katsikogianni, M., & Missirlis, Y. (2004). Concise review of mechanisms of bacterial adhesion to biomaterials and of techniques used in estimating bacteria-material interactions. European Cells and Materials, 8, 37-57. doi:10.22203/ecm.v008a05Ruiz-Rico, M., Fuentes, C., Pérez-Esteve, É., Jiménez-Belenguer, A. I., Quiles, A., Marcos, M. D., … Barat, J. M. (2015). Bactericidal activity of caprylic acid entrapped in mesoporous silica nanoparticles. Food Control, 56, 77-85. doi:10.1016/j.foodcont.2015.03.016Zahedi Bialvaei, A., Rahbar, M., Yousefi, M., Asgharzadeh, M., & Samadi Kafil, H. (2016). Linezolid: a promising option in the treatment of Gram-positives. Journal of Antimicrobial Chemotherapy, 72(2), 354-364. doi:10.1093/jac/dkw450Chang, Y., McLandsborough, L., & McClements, D. J. (2012). Cationic Antimicrobial (ε-Polylysine)–Anionic Polysaccharide (Pectin) Interactions: Influence of Polymer Charge on Physical Stability and Antimicrobial Efficacy. Journal of Agricultural and Food Chemistry, 60(7), 1837-1844. doi:10.1021/jf204384sShukla, S. C., Singh, A., Pandey, A. K., & Mishra, A. (2012). Review on production and medical applications of ɛ-polylysine. Biochemical Engineering Journal, 65, 70-81. doi:10.1016/j.bej.2012.04.001Liu, J.-N., Chang, S.-L., Xu, P.-W., Tan, M.-H., Zhao, B., Wang, X.-D., & Zhao, Q.-S. (2020). Structural Changes and Antibacterial Activity of Epsilon-poly-l-lysine in Response to pH and Phase Transition and Their Mechanisms. Journal of Agricultural and Food Chemistry, 68(4), 1101-1109. doi:10.1021/acs.jafc.9b0752

An ex vivocystic fibrosis model recapitulates key clinical aspects of chronic Staphylococcus aureus infection

Staphylococcus aureus is one of the most prevalent organisms isolated from the airways of people with cystic fibrosis (CF), predominantly early in life. Yet its role in the pathology of lung disease is poorly understood. Clinical studies are limited in scope by age and health of participants and in vitro studies are not always able to accurately recapitulate chronic disease characteristics such as the development of small colony variants. Further, animal models also do not fully represent features of clinical disease: in particular, mice are not readily colonized by S. aureus and when infection is established it leads to the formation of abscesses, a phenomenon almost never observed in the human CF lung. Here, we present details of the development of an existing ex vivo pig lung model of CF infection to investigate the growth of S. aureus. We show that S. aureus is able to establish infection and demonstrates clinically significant characteristics including small colony variant phenotype, increased antibiotic tolerance and preferential localisation in mucus. Tissue invasion and the formation of abscesses were not observed, in line with clinical data

Oligonucleotide-capped nanoporous anodic alumina biosensor as diagnostic tool for rapid and accurate detection of Candida auris in clinical samples

[EN] Candida auris has arisen as an important multidrug-resistant fungus because of several nosocomial outbreaks and elevated rates of mortality. Accurate and rapid diagnosis of C. auris is highly desired; nevertheless, current methods often present severe limitations and produce misidentification. Herein a sensitive, selective, and time-competitive biosensor based on oligonucleotide-gated nanomaterials for effective detection of C. auris is presented. In the proposed design, a nanoporous anodic alumina scaffold is filled with the fluorescent indicator rhodamine B and the pores blocked with different oligonucleotides capable of specifically recognize C. auris genomic DNA. Gate opening modulation and cargo delivery is controlled by successful DNA recognition. C. auris is detected at a concentration as low as 6 CFU/mL allowing obtaining a diagnostic result in clinical samples in one hour with no prior DNA extraction or amplification steps.The authors want to thank the Spanish Government (project RTI2018-100910-B-C41 (MCIU/AEI/FEDER, UE)), the Generalitat Valenciana (project PROMETEO/2018/024), Universitat Politecnica de Valencia-Instituto de Investigacion Sanitaria La Fe (AURISGATE project) and Centro de Investigacion Biomedica en Red en Bioingenieria, Biomateriales y Nanomedicina (NANOPATH AND CANDI-EYE projects) for support. L.P thanks MINECO for his predoctoral fellowship. S.S. thanks the Instituto de Salud Carlos III and the European Social Fund for the financial support "Sara Borrell" (CD16/000237).Pla, L.; Santiago-Felipe, S.; Tormo-Mas, MÁ.; Ruiz-Gaitán, A.; Peman, J.; Valentín, E.; Sancenón Galarza, F.... (2021). Oligonucleotide-capped nanoporous anodic alumina biosensor as diagnostic tool for rapid and accurate detection of Candida auris in clinical samples. Emerging microbes & infections. 10(1):407-415. https://doi.org/10.1080/22221751.2020.187041140741510

Essential topics for the regulatory consideration of phages as clinically valuable therapeutic agents: A perspective from Spain

This article belongs to the Special Issue Bacteriophages-Based Technologies for a One Health Society: Applications in Clinical, Veterinary, and Industrial Settings.Antibiotic resistance is one of the major challenges that humankind shall face in the short term. (Bacterio)phage therapy is a valuable therapeutic alternative to antibiotics and, although the concept is almost as old as the discovery of phages, its wide application was hindered in the West by the discovery and development of antibiotics in the mid-twentieth century. However, research on phage therapy is currently experiencing a renaissance due to the antimicrobial resistance problem. Some countries are already adopting new ad hoc regulations to favor the short-term implantation of phage therapy in clinical practice. In this regard, the Phage Therapy Work Group from FAGOMA (Spanish Network of Bacteriophages and Transducing Elements) recently contacted the Spanish Drugs and Medical Devices Agency (AEMPS) to promote the regulation of phage therapy in Spain. As a result, FAGOMA was asked to provide a general view on key issues regarding phage therapy legislation. This review comes as the culmination of the FAGOMA initiative and aims at appropriately informing the regulatory debate on phage therapy.This work was supported by Grant RED2018-102589-T funded by MCIN/AEI/10.13039/501100011033. R.V. and D.G. were supported by the Research Foundation–Flanders (FWO) under grant [G066919N]. Pe. G. and R.V. were supported by the Spanish Ministry of Science and Innovation (Grant number SAF2017-88664-R), with additional funding provided by the Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), an initiative of the Instituto de Salud Carlos III. P.D.-C. was financially supported by a Ramón y Cajal contract RYC2019-028015-I and project PID2020-112835RA-I00 funded by MCIN/AEI/10.13039/501100011033, ESF Invest in your future, project SEJIGENT/2021/014, funded by Conselleria d’Innovació, Universitats, Ciència i Societat Digital (Generalitat Valenciana), and project AP2020-27 funded by VLC-Biomed (UV-La Fe 2020 Programa Acciones Preparatorias). M.M. was supported by project PID2020-113355GB-I00 of Spanish Ministry of Science and Innovation /Agencia Estatal de Investigación (AEI)/European regional fund (ERF). M.Á.T.-M. was supported by Spanish Ministry of Science and Innovation (Grant number SAF2017- 82251-R).Peer reviewe

An ex vivo cystic fibrosis model recapitulates key clinical aspects of chronic Staphylococcus aureus infection

Staphylococcus aureus is the most prevalent organism isolated from the airways of people with cystic fibrosis (CF), predominantly early in life. Yet its role in the pathology of lung disease is poorly understood. In mice, and many experiments using cell lines, the bacterium invades cells or interstitium, and forms abscesses. This is at odds with the limited available clinical data: interstitial bacteria are rare in CF biopsies and abscesses are highly unusual. Bacteria instead appear to localize in mucus plugs in the lumens of bronchioles. We show that, in an established ex vivo model of CF infection comprising porcine bronchiolar tissue and synthetic mucus, S. aureus demonstrates clinically significant characteristics including colonization of the airway lumen, with preferential localization as multicellular aggregates in mucus, initiation of a small colony variant phenotype and increased antibiotic tolerance of tissue-associated aggregates. Tissue invasion and abscesses were not observed. Our results may inform ongoing debates relating to clinical responses to S. aureus in people with CF

Aptamer-capped nanoporous anodic alumina for SARS-CoV-2 spike protein detection

The COVID-19 pandemic, which began in 2019, has highlighted the importance of testing and tracking infected individuals as a means of mitigating the spread of the virus. In this context, the development of sensitive and rapid methods for the detection of SARS-CoV-2, the virus responsible for COVID-19, is crucial. Herein, a biosensor based on oligonucleotide-gated nanomaterials for the specific detection of SARS-CoV-2 spike protein is presented. The sensing system consists of a nanoporous anodic alumina disk loaded with the fluorescent indicator rhodamine B and capped with a DNA aptamer that selectively binds the SARS-CoV-2 spike protein. The system is initially evaluated using pseudotype virus systems based on vesicular stomatitis virus carrying different SARS-CoV-2 S-proteins on their surface. When the pseudotype virus is present, the cap of the solid is selectively removed, triggering the release of the dye from the pore voids to the medium. The nanodevice demonstrated its ability to detect pseudotype virus concentrations as low as 7.5·103 PFU mL. In addition, the nanodevice is tested on nasopharyngeal samples from individuals suspected of having COVID-19.This study was supported by the Spanish Government (projects PID2021-126304OB-C41, and PID2021-122875OB-100 (MCUI/AEI/FEDER, UE)), the Generalitat Valenciana (project no.2 RD 180/2020, CIPROM/2021/007), Supera COVID-19 Fund (DIACOVID project), the Universitat Politècnica de València−Instituto de Investigación Sanitaria La Fe (IIS-LaFe) (SARS-COV-2-SEEKER and VISION-COV projects), and by the European Commission –NextGenerationEU, through CSIC's Global Health Platform (PTI Salud Global) to Ron Geller. The project leading to this application has received funding from the European Union's Horizon EUROPE research and innovation programme under grant agreement No 101093042. Isabel Caballos thanks the Instituto de Salud Carlos III for her predoctoral fellowship (IFI21/00008). Alba López-Palacios thanks the Ministerio de Universidades for her predoctoral grant (FPU20/05297). Ron Geller holds a Ramon y Cajal fellowship from the Spanish Ministerio de Economía y Competitividad (RYC-2015-17517).Peer reviewe

Human Papilloma Virus DNA Detection in Clinical Samples Using Fluorogenic Probes Based on Oligonucleotide Gated Nanoporous Anodic Alumina Films

[EN] In this work, fluorogenic probes based on oligonucleotide capped nanoporous anodic alumina films are developed for specific and sensitive detection of human papilloma virus (HPV) DNA. The probe consists of anodic alumina nanoporous films loaded with the fluorophore rhodamine B (RhB) and capped with oligonucleotides bearing specific base sequences complementary to genetic material of different high-risk (hr) HPV types. Synthesis protocol is optimized for scale up production of sensors with high reproducibility. The sensors' surfaces are characterized by scanning electron microscopy (HR-FESEM) and atomic force microscopy (AFM) and their atomic composition is determined by energy dispersive X-ray spectroscopy (EDXS). Oligonucleotide molecules onto nanoporous films block the pores and avoid diffusion of RhB to the liquid phase. Pore opening is produced when specific DNA of HPV is present in the medium, resulting in RhB delivery, that is detected by fluorescence measurements. The sensing assay is optimized for reliable fluorescence signal reading. Nine different sensors are synthesized for specific detection of 14 different hr-HPV types in clinical samples with very high sensitivity (100%) and high selectivity (93-100%), allowing rapid screening of virus infections with very high negative predictive values (100%).The authors gratefully acknowledge financial support projects for PID2021-126304OB-C41 and PDI2021-122875OB-100 funded by MCIN/AEI /10.13039/501100011033 / FEDER, UE, project DTS18/00090 from Instituto de Salud Carlos III and FEDER and Generalitat Valenciana (Project PROMETEO CIPROM/2021/007). This work was also supported by CIBER -Consorcio Centro de Investigacion Biomedica en Red- (CB06/01/2012), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovacion. The authors thank UPV electron microscopy service for technical support.Hernández-Montoto, A.; Aranda, MN.; Caballos-Gómez, MI.; López-Palacios, A.; Tormo-Mas, MÁ.; Peman, J.; Prieto Rodríguez, M.... (2023). Human Papilloma Virus DNA Detection in Clinical Samples Using Fluorogenic Probes Based on Oligonucleotide Gated Nanoporous Anodic Alumina Films. Advanced Healthcare Materials (Online). 12(22). https://doi.org/10.1002/adhm.202203326122

Aptamer-Capped Nanoporous Anodic Alumina for SARS-CoV-2 Spike Protein Detection

[EN] The COVID-19 pandemic, which began in 2019, has highlighted the importance of testing and tracking infected individuals as a means of mitigating the spread of the virus. In this context, the development of sensitive and rapid methods for the detection of SARS-CoV-2, the virus responsible for COVID-19, is crucial. Here, a biosensor based on oligonucleotide-gated nanomaterials for the specific detection of SARS-CoV-2 spike protein is presented. The sensing system consists of a nanoporous anodic alumina disk loaded with the fluorescent indicator rhodamine B and capped with a DNA aptamer that selectively binds the SARS-CoV-2 spike protein. The system is initially evaluated using pseudotype virus systems based on vesicular stomatitis virus carrying different SARS-CoV-2 S-proteins on their surface. When the pseudotype virus is present, the cap of the solid is selectively removed, triggering the release of the dye from the pore voids to the medium. The nanodevice demonstrated its ability to detect pseudotype virus concentrations as low as 7.5 center dot 10(3) PFU mL. In addition, the nanodevice is tested on nasopharyngeal samples from individuals suspected of having COVID-19.This study was supported by the Spanish Government (projects PID2021-126304OB-C41, and PID2021-122875OB-100 (MCUI/AEI/FEDER, UE)), the Generalitat Valenciana (project no.2 RD 180/2020, CIPROM/2021/007), Supera COVID-19 Fund (DIACOVID project), the Universitat Politecnica de Valencia-Instituto de Investigacion Sanitaria La Fe (IIS-LaFe) (SARS-COV-2-SEEKER and VISION-COV projects), and by the European Commission -NextGenerationEU, through CSIC's Global Health Platform (PTI Salud Global) to Ron Geller. The project leading to this application has received funding from the European Union's Horizon EUROPE research and innovation programme under grant agreement No 101093042. Isabel Caballos thanks the Instituto de Salud Carlos III for her predoctoral fellowship (IFI21/00008). Alba Lopez-Palacios thanks the Ministerio de Universidades for her predoctoral grant (FPU20/05297). Ron Geller holds a Ramon y Cajal fellowship from the Spanish Ministerio de Economia y Competitividad (RYC-2015-17517). Figure 1 done with BioRender.com. The use of samples from human subjects was approved by the Medicaments Research Ethics Commmittee, CEIm of Hospital Universitari i Politecnic La Fe (no. 2021-012-1). Informed written consent was obtained from all participants or next of kin prior to the research.Caballos-Gómez, MI.; Aranda, MN.; López-Palacios, A.; Pla, L.; Santiago Felipe, S.; Hernández-Montoto, A.; Tormo-Mas, MÁ.... (2023). Aptamer-Capped Nanoporous Anodic Alumina for SARS-CoV-2 Spike Protein Detection. Advanced Materials Technologies. 8(11):1-10. https://doi.org/10.1002/admt.20220191311081