Nowadays there is an increasing focus for avoiding bacterial colonization in a medical device after implantation. Bacterial infection associated with prosthesis implantation, or even along the lifetime of the implanted prosthesis, entails a serious problem, emphasized with immunocompromised patients. This work shows a new methodology to create highly hydrophobic micro-/nanostructured silver antibacterial surfaces against Gram-positive and Gram-negative bacteria, using low-pressure plasma. PDMS (polydimethylsiloxane) samples, typically used in tracheal prosthesis, are coated with PFM (pentafluorophenyl methacrylate) through PECVD (plasma enhance chemical vapor deposition) technique. PFM thin films offer highly reactive ester groups that allow them to react preferably with amine bearing molecules, such as amine sugar, to create controlled reductive surfaces capable of reducing silver salts to a nanostructured metallic silver. This micro-/nanostructured silver coating shows interesting antibacterial properties combined with an antifouling behavior causing a reduction of Gram-positive and Gram-negative bacteria viability. In addition, these types of silver-coated samples show no apparent cytotoxicity against COS-7 cells.
Catheter-associated
urinary tract infections (CAUTIs) are the most
common health care-associated infections due to rapid bacterial colonization+
and biofilm formation in urinary catheters. This behavior has been
extensively documented in medical devices. However, there is a few
literature works on CAUTI providing a model that allows the exhaustive
study of biofilm formation in a urinary environment. The development
of an effective model would be helpful to identify the factors that
promote the biofilm formation and identify strategies to avoid it.
In this work, we have developed a model to test biofilm formation
on urinary medical device surfaces by simulating environmental and
physical conditions using a quartz crystal microbalance with dissipation
(QCM-D) module with an uropathogenic strain. Moreover, we used the
developed model to study the role of human albumin present in artificial urine at high concentrations
because of renal failure or heart-diseases in patients. Despite model
limitations using artificial urine, these tests show that human albumin
can be considered as a promoter of biofilm formation on hydrophobic
surfaces, being a possible risk factor to developing a CAUTI.
Strain sensors for wearable electronic devices have received attention due to their potential application in medicine for physiological monitoring or as part of advanced prosthetics. However, low sensitivity values as well as complex fabrication procedures remain significant challenges limiting the applicability. This work presents the fabrication of a strain sensor based on the separation of silver microplates immobilized on a stretchable substrate. The deposition of the microplates is achieved through the exposition of a glucosamine‐functionalized surface to the Tollens’ reagent, being a versatile fabrication methodology able to be implemented in a wide range of substrates. The obtained sensors present a high stretchability (>100%), high conductivity (105 S m–1), good linearity (R2 > 0.98 under 30% strain), good hysteresis properties, and high sensitivity (up to GF = 900 000). Hence, the sensors allow the measurement of very small deformations even in dynamic range, where it presents a stable linear response for the quantification of cyclic deformations of 0.02% strain. Moreover, the applicability of these sensors has been studied in motion‐sensing devices and in a pressure sensor revealing that this technology may expand the potential applications of wearable electronic devices.
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