75 research outputs found
Preparación de enzimas del Aspergillus Orizae y estudio de su utilización industrial
Fil: Guagnini, Omar A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: Jacovkis, David. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
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
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