The need for personal protective equipment increased exponentially in response to the Covid-19 pandemic. To cope with the mask shortage during springtime 2020, a French consortium was created to find ways to reuse medical and respiratory masks in healthcare departments. The consortium addressed the complex context of the balance between cleaning medical masks in a way that maintains their safety and functionality for reuse, with the environmental advantage to manage medical disposable waste despite the current mask designation as single-use by the regulatory frameworks. We report a Workflow that provides a quantitative basis to determine the safety and efficacy of a medical mask that is decontaminated for reuse. The type IIR polypropylene medical masks can be washed up to 10 times, washed 5 times and autoclaved 5 times, or washed then sterilized with radiations or ethylene oxide, without any degradation of their filtration or breathability properties. There is loss of the anti-projection properties. The Workflow rendered the medical masks to comply to the AFNOR S76-001 standard as “type 1 non-sanitory usage masks”. This qualification gives a legal status to the Workflow-treated masks and allows recommendation for the reuse of washed medical masks by the general population, with the significant public health advantage of providing better protection than cloth-tissue masks. Additionally, such a legal status provides a basis to perform a clinical trial to test the masks in real conditions, with full compliance with EN 14683 norm, for collective reuse. The rational reuse of medical mask and their end-of-life management is critical, particularly in pandemic periods when decisive turns can be taken. The reuse of masks in the general population, in industries, or in hospitals (but not for surgery) has significant advantages for the management of waste without degrading the safety of individuals wearing reused masks.

The application of nanotechnology principles and methodology to problems in biotechnology is providing an exciting discipline that will generate a revolution of novel applications in several arenas. Applications of nanotechnology range from novel nanosensors, to novel methods for sorting and delivering bioactive molecules, to novel drug-delivery systems. The philosophical approaches to finding solutions to those application areas historically have relied on engineering and the physical sciences to produce materials and processes that are then tested for efficacy in the biological environment. The difficulty in that approach is that it relies on an entirely empirical process in testing new materials or processes for compatibility in biological systems, and then subsequently for ultimate testing of the new material or process in humans. Whilst our intention with this book is not to denigrate the philosophy of that approach, nor to make claims that biological systems are completely predictable and thus able to be entirely modelled, the alternative approach that this book aims to address is that of nanobiotechnology. Put simply, the alternative that nanobiotechnology offers is to more closely utilise biological principles in guiding and influencing the materials and processes that are developed from engineering and the physical sciences for use in medical applications.At this point it is worth considering a forward-looking paper that was published in 2001. Prokop 1 made several pertinent statements that clearly embody the philosophy of nanobiotechnology. Those statements were made especially with regard to bioartificial organs which involve the design, modification, growth and maintenance of living tissues embedded in natural or synthetic scaffolds to enable them to perform complex biochemical functions. Those thoughts exemplify the essence of the nanobiotechnological approach that this book aims to convey. Prokop 1 thought that future research in the area of bioartificial organs would 1

As part of our research into the liver-directed gene therapy of Type I diabetes, we have engineered a human hepatoma cell line (HEPG2ins/g cells) to store and secrete insulin to a glucose stimulus. The aim of the present study was to determine whether HEPG2ins/g cells respond to glucose via signaling pathways that depend on ATP-sensitive potassium channels (KATP). Using patch-clamp electrophysiology with symmetrical KCl solutions, the single-channel conductance of KATP was 61pS. KATP was inhibited by ATP (1 mM) or cAMP (50 microM) applied to the cytosolic side of the membrane. Single KATP channels and macroscopic whole-cell currents were inhibited by glucose (20 mM) and glibenclamide (20 microM) and were activated by diazoxide (150 microM). Immunoprecipitation and Western blot analysis confirmed the presence of Kir6.2 KATP channel subunit protein in HEPG2ins/g and HEPG2ins cells. Using radioimmunoassay techniques, we report that exposure of the cells to tolbutamide (100 microM) resulted in an increase in insulin secretion from 0.3 +/- 0.05 to 1.8 +/- 0.2 pmol insulin/10(6) cells and glibenclamide (20 microM) from 0.4 +/- 0.06 to 2.1 +/- 0.3 (n=4), similar to what is seen on glucose (20 mM) stimulation. Diazoxide (150 microM) completely inhibited glucose-stimulated insulin release. Glucose 20 mM and glibenclamide 100 microM increased intracellular Ca2+ level in the HEPG2ins/g cells. However, glucose 20 mM did not stimulate a rise in intracellular Ca2+ in the un-transfected parent cell-line HEPG2. We used confocal microscopy to confirm that glucose (20 mM) stimulated the release of insulin from the fluorescently labeled secretion granules in the cells. Furthermore, glibenclamide (20 microM) also stimulated the release of insulin from fluorescently labeled secretion granules, and diazoxide (150 microM) blocked that stimulated release of insulin. Our results suggest that HEPG2ins/g cells respond to glucose via signaling pathways that depend on KATP, similar to a normal pancreatic beta cell.

The development of nanostructured microcapsules based on a biomimetic lipid bilayer membrane (BLM) coating of poly(sodium styrenesulfonate) (PSS)/poly(allylamine hydrochloride) (PAH) polyelectrolyte hollow microcapsules is reported. A novel engineered ion channel, gramicidin (bis‐gA), incorporated into the lipid membrane coating provides a functional capability to control transport across the microcapsule wall. The microcapsules provide transport and permeation for drug‐analog neutral species, as well as positively and negatively charged ionic species. This controlled transport can be tuned for selective release biomimetically by controlling the gating of incorporated bis‐gA ion channels. This system provides a platform for the creation of “smart” biomimetic delivery vessels for the effective and selective therapeutic delivery and targeting of drugs.

Pseudomonas aeruginosa is the second-leading cause of nosocomial infections and pneumonia in hospitals. Because of its extraordinary capacity for developing resistance to antibiotics, treating infections by Pseudomonas is becoming a challenge, lengthening hospital stays, and increasing medical costs and mortality. The outer membrane protein OprF is a well-conserved and immunogenic porin playing an important role in quorum sensing and in biofilm formation. Here, we used a bacterial cell-free expression system to reconstitute OprF under its native forms in liposomes and we demonstrated that the resulting OprF proteoliposomes can be used as a fully functional recombinant vaccine against P. aeruginosa. Remarkably, we showed that our system promotes the folding of OprF into its active open oligomerized state as well as the formation of mega-pores. Our approach thus represents an easy and efficient way for producing bacterial membrane antigens exposing native epitopes for vaccine purposes.