Magnetic hydrogel based shoe insoles for prevention of diabetic foot

Abstract Currently, plastic/rubber/silicone based shoe inserts are used as preventive approach against diabetic foot which are non-degradable, non-absorbent and contains magnet protrusions, making them highly uncomfortable. These are discarded and thrown away after their service life, causing soil and marine pollution. Thus, the objective of this study was to evaluate polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) based magnetic hydrogels prepared by physical crosslinking as an alternative for diabetic shoe inserts. Hydrogels prepared by moist heat treatment with different concentration of strontium ferrite nanoparticles (MG) are evaluated based on their structural, physico-chemical, morphological, thermal, mechanical, thermo-mechanical, swelling behavior, surface wetting, magnetic and rheological properties. It was observed that incorporation of MG resulted in improvement in overall properties. Infrared spectroscopy revealed strong hydrogen bonding interaction between CMC and PVA. The surface micrographs showed uniform dispersion of MG throughout PVA/CMC matrix. The results showed the improvement in flexibility and tensile strength of the PVA/CMC hydrogels with the incorporation of MG by ~40 and ~20%, respectively. Moreover, the magnetic hydrogels could absorb ~300% moisture of their original weight which is necessary to avoid growth of microbes on skin. Thus, PVA/CMC/MG hydrogels can be considered as a biodegradable alternative for diabetic shoe insoles.