Development and characterization of xyloglucan-poly(vinyl alcohol) hydrogel membrane for wireless smart wound dressings

Research which addresses advanced wound management can contribute to the needs of modern healthcare, especially in situations that require continuous monitoring, analysis, responsive therapeutic treatments and data recording. The development of “smart” bandages and dressings that can remotely monitor relevant parameters for the wound healing process without a hospital intervention can be very useful tools for patients and physicians and for advancing the understanding of the healing process. In the present work, biocompatible xyloglucan/poly(vinyl alcohol) hydrogels are being developed as smart wound dressings that, in addition to the traditional favorable properties of hydrogels as skin care material, can sense relevant biological parameters and provide support for remote monitoring of wound healing itself. The swelling behavior of the films by simulated biological fluids and the induced changes of their dielectric properties in a wide range of frequencies (100-106 Hz and 108-1011Hz) are investigated. The highest frequency band is particularly relevant for the optimization of UHF RFID smart dressings. The swelling-induced microstructure and rheological properties modifications are also evaluated by SEM microscopy and dynamic mechanical measurements, respectively. The films absorb simulated body fluids up to approximately four times their initial dry weight, without losing their integrity but undergoing significant microstructural changes. We observed relevant linear increases of electric conductivity and permittivity with the swelling degree, with an abrupt change of slope that is related to the network rearrangements occurring upon swelling. A parallel biological study on the same hydrogels films is demonstrating that they are non- cytotoxic, fully hemocompatible, non-adhesive to the wound and able to provide protection from bacterial infiltration. These results altogether encourage in proceeding with further development and evaluation of these hydrogel membranes as smart wound dressings.