AbstractPolyurethane (PU) elastomers represent an important class of segmented copolymers. Thanks to many available chemical compositions, a rather broad range of chemical, physical, and biocompatible properties of PU can be obtained. These polymers are often characterized by high tensile and tear strength, elongation, fatigue life, and wear resistance. However, their relatively high permeability towards gases and water as well as their biocompatibility still limits the PU’s practical application, especially for biomedical use, for example, in implants and medical devices. In this review, the barrier and permeability properties of segmented PUs related to their chemical structure and physical and chemical properties have been discussed, including the latest developments and different approaches to improve the PU barrier properties.
One
major factor inhibiting natural wound-healing processes is
infection through bacterial biofilms, particularly in the case of
chronic wounds. In this study, the micro/nanostructure of a wound
dressing was optimized in order to obtain a more efficient antibiofilm
protein-release profile for biofilm inhibition and/or detachment.
A 3D substrate was developed with asymmetric polyhydroxyalkanoate
(PHA) membranes to entrap Dispersin B (DB), the antibiofilm protein.
The membranes were prepared using wet-induced phase separation (WIPS).
By modulating the concentration and the molecular weight of the porogen
polymer, polyvinylpyrrolidone (PVP), asymmetric membranes with controlled
porosity were obtained. PVP was added at 10, 30, and 50% w/w, relative
to the total polymer concentration. The physical and kinetic properties
of the quaternary nonsolvent/solvent/PHA/PVP systems were studied
and correlated with the membrane structures obtained. The results
show that at high molecular weight (M
w = 360 kDa) and high PVP content (above 30%), pore size decreased
and the membrane became extremely brittle with serious loss of physical
integrity. This brittle effect was not observed for low molecular
weight PVP (M
w = 40 kDa) at comparable
contents. Whatever the molecular weight, porogen content up to 30%
increased membrane surface porosity and consequently protein uptake.
Above 30% porogen content, the pore size and the physical integrity/mechanical
robustness both decreased. The PHA membranes were loaded with DB and
their antibiofilm activity was evaluated against Staphylococcus
epidermidis biofilms. When the bacterial biofilms were exposed
to the DB-loaded PHA membrane, up to 33% of the S. epidermidis biofilm formation was inhibited, while 26% of the biofilm already
formed was destroyed. These promising results validate our approach
based on the development of bioactive-protein-loaded asymmetric membranes
for antibiofilm strategies in situations where traditional antibiotic
therapies are ineffective.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.