Auto-cross-linking hydrogels of hydrogen peroxide-oxidized pectin and gelatin for applications in controlled drug delivery

Pectin-based hydrogels for biomedical applications have attracted recent attention due to their low cost, large availability of the materials, and high levels of biocompatibility. Specifically, periodate-oxidized pectin has been combined with chitosan and gelatin to form different structures. However, hydrogen peroxide-mediated oxidation of pectin has not been studied for this application; furthermore, there is little information on the effect of the degree of oxidation on hydrogel characteristics nor has the feasibility of these systems as controlled drug delivery matrices been explored. Thus, the present work proposes to study the properties of gelatin-peroxide-oxidized pectin hydrogels as drug delivery systems in wound dressing applications. Combinations of pectin at different degrees of oxidation (high, low, and native pectin) and gelatin were analyzed and tested by swelling properties, reswelling from xerogel and aerogel forms, SEM, FTIR, and drug release. It was determined that hydrogels that contained oxidized pectin had improved swelling ratios and stability, at 32°C, compared to those with native pectin and only gelatin. The porosity of the oxidized pectin hydrogels allowed to have sustained and high release rates, which would make them an attractive alternative for wound dressings.