Supramolecular elastomer based on polydimethylsiloxanes (SESi) film: synthesis, characterization, biocompatibility, and its application in the context of wound dressing

Supramolecular elastomer based on polydimethylsiloxanes (SESi) is a kind of novel elastomer cross-linked by the multihydrogen bonds supplied by the functional groups linked to the end of the PDMS chains, such as amide, imidazolidone, pending urea (1,1-dialkyl urea), and bridging urea (1,3-dialkyl urea). SESi showed lower glass transition temperature (T g) at about -113 °C because of the softer chain of PDMS, and could show real rubber-like elastic behaviors and acceptable water vapor transmission rate under room temperature. The high biocompatibility of SESi in the form of films was demonstrated by the cytotoxicity evaluation (MTT cytotoxicity assay and direct contact assay), hemolysis assay, and skin irritation evaluation. Based on detailed comparisons between commercial Tegaderm(™) film and SESi film using a full-thickness rat skin model experiment, it was found that SESi film showed similar wound contraction rate as that of Tegaderm(™) film on day seven, 10, and 14; only on day five, SESi film showed a significant (p < 0.05) lower wound contraction rate. And, the wounds covered with SESi film were filled with new epithelium without any significant adverse reactions, similar with that of Tegaderm(™) film.