Biomedical devices based on silicone
are essential tools in modern
healthcare but can be compromised by the development of device-acquired
infections (DAIs). Unfortunately, the continued rise of antibiotic-resistant
organisms makes current strategies to combat DAIs insufficient. Recently,
the use of photoactive coatings that produce reactive oxygen species,
specifically singlet oxygen (1O2), has attracted
attention as a potential alternative to traditional strategies to
prevent DAIs. However, the synthesis and characterization of silicone
devices capable of 1O2 production are not trivial.
Development is hindered by the incompatibility of photosensitizers
with the silicone matrix and an incomplete understanding of how the
method of incorporation impacts 1O2 production.
Using the Piers–Rubinsztajn reaction, the photosensitizer 5,10,15,20-(tetra-3-methoxyphenyl)porphyrin
(TPMP) was derivatized to be compatible with silicone matrices without
the assistance of solvents and could be incorporated either covalently
or physically within silicone elastomers. Electron paramagnetic resonance
measurements indicated that 1O2 was more efficiently
generated from elastomers containing a covalently cross-linked TPMP
derivative than their physically dispersed counterparts, due to the
minimization of aggregates.