Rifampicin-loaded electrospun polycaprolactone membranes: Characterization of stability, antibacterial effects and urotheliocytes proliferation

Pathological conditions such as infections, cancer, inflammation, or iatrogenic lesions, can hinder the cor-rect functionality of the ureter and its structural integrity. Several strategies for the regeneration of the ureter and the restoration of its functionality are available but the best strategy has not been reached yet. Among the proposed strategies, a promising one is the development of tubular scaffolds, in particular exploiting electrospinning technique. In this work, antibacterial electrospun polycaprolactone/rifampicin (PCL/Rif) membranes were prepared and characterized. The membranes are characterized by randomly oriented nanofibers with a homogeneous diameter, as determined by scanning electron microscopy. The mechanical characterization, performed with uniaxial tensile tests, showed a suitable stability over time and a proper deformability. The rifampicin release, investigated by UV spectrophotometry, showed a burst release in the first part of the experiment and a sustained release over time. The membranes are biocompatible and able to support the adhesion and proliferation of urotheliocytes. Moreover, PCL/Rif membranes showed an antibacterial activity against Escherichia coli and other bacterial strains belonging to the "ESKAPE" group. Considering the possibility to use the electrospinning for the production of tubu-lar scaffolds, the described membranes represent a promising starting point for the preparation of uret-eral scaffolds with antibacterial properties.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Antibacterial rifampicin-loaded electrospun polycaprolactone membranes for ureteral regeneration

Author of the study: Nowadays partial or complete ureteral loss following resection or injuries of various etiology is managed with different surgical techniques involving local tissue flaps or autologous tissues interposition. In the last years ureteral tissue engineering using membranes, tubular scaffolds or decellularized matrices has shown promising results for ureteral substitution. The aim of this study is to evaluate the use of antibacterial electrospun polycaprolactone/ rifampicin (PCL/RIF) membranes for the production of ureteral scaffolds with antibacterial properties. Materials and methods: Electrospinning processwas used to produce the membranes that were subsequently impregnated with rifampicin. Membranes stability was evaluated by immersion in Simulated Body Fluid (SBF) at 37 °C. Mechanical properties were evaluated by uniaxial tensile tests, Young’s modulus was calculated for each sample. UV spectrophotometry was used to evaluate in vitro release of rifampicin. The ability of PCL/Rif membranes to sustain cell adhesion and proliferation was evaluated by seeding human urothelial bladder carcinoma cells on the membranes. In order to investigate the antibacterial effect of PCL/Rif membranes, in vitro antibacterial tests were performed using bacterial strains belonging to the “ESKAPE” group. Results: PCL/Rif membranes are characterized by a random distribution of fibers with an average diameter of 0.52 μm.Water contact angle for PCL and PCL/Rif membranes is around 125° and decreases to 0° after air-plasma treatment. When culture medium is used as testing fluid PCL and PCL/Rif contact angles are 116° and 12° respectively. Membranes are deformable up to 300% of their initial dimension and possess an elastic Young modulus of about 20 kPa; after 3 weeks membranes gain the property to sustain a 100% deformation before rupture. The 72% of rifampicin load is released by the membranes in the first 24 hours. Proliferation assay showed a seven-fold increase of cell number adhered on the membranes after 7 days of culture. At the same time in presence of PCL/Rif membranes, rates of bacterial proliferation inhibition ranged from 75 to 94% compared to controls. Conclusions: PCL/Rif membranes represent a promising starting point in the production of ureteral scaffolds with antibacterial properties for ureteral substitution

Memória dos desaparecidos: algumas estratégias visuais

The politics of forced disappearance, established by the Junta Militar that ruled Argentina between 1976 and 1983, had as a corollary the denial of the desaparecido’s existence, defined “non entity” by president Jorge Rafael Videla in a press conference held in December 1979. The attempt to erase the very existence of desaparecidos has been contested by public actions and artistic interventions that enunciate the theme of the memory in many ways.A política de desaparecimentos forçados, implementada pela Junta Militar que governou a Argentina entre 1976 e 1983, tinha como corolário a negação da existência do desaparecido, denominado “não entidade” pelo presidente Jorge Rafael Videla numa coletiva de imprensa, em dezembro de 1979. Essa política de apagamento da existência dos desaparecidos é posta em xeque por ações públicas e intervenções artísticas, que articulam, de diversas maneiras, a problemática da memória

A multi-element psychosocial intervention for early psychosis (GET UP PIANO TRIAL) conducted in a catchment area of 10 million inhabitants: study protocol for a pragmatic cluster randomized controlled trial

Multi-element interventions for first-episode psychosis (FEP) are promising, but have mostly been conducted in non-epidemiologically representative samples, thereby raising the risk of underestimating the complexities involved in treating FEP in 'real-world' services

\u201cDall\u2019invenzione all\u2019impresa. Marconi e la Wireless Telegraph & Signal Company\u201d

Il saggio esamina la fase iniziale di sviluppo della invenzione di Guglielmo Marconi e le vicende portarono alla costituzione della Wireless Telegraph & Signal Company (poi divenuta Marconi Wireless Telegraph Company), con particolare riguardo per la analisi dei costi sostenuti nel corso di questo processo. L\u2019obiettivo \ue8 di individuare quali sono stati i settori in cui si sono concentrate le spese (in particolare consulenze brevettuali e legali, dimostrazioni ed esperimenti) e di fornire indicatori che suggeriscano quale possa essere stata l\u2019entit\ue0 degli investimenti che hanno consentito a Marconi e alla sua societ\ue0 di conquistare una posizione di leadership nella nuova tecnologia. Questa analisi consente inoltre di ricostruire con maggior precisione il ruolo di Marconi e degli altri co-protagonisti nel decollo della societ\ue0, i rispettivi loro obiettivi e le loro strategie. The essay is a study of the early stages in the development of Guglielmo Marconi\u2019s invention and in the creation of the Wireless Telegraph & Signal Company (later to become the Marconi Wireless Telegraph Company); special attention is paid to the analysis of the costs of that process. The aim is to identify the sectors in which expenses were particularly high (patenting, legal assistance, experiments and demonstrations), and to provide indicators of the amount of the investments that allowed Marconi and his company to establish their leadership in the development of the new technology. This approach offers also new insights into the role of Marconi and of other co-protagonists in the take-off of the company, their distinctive objectives and agendas