Polyvinyl alcohol/casein hydrogels with oxymatrine eluting ability for cancer-related wound management

Malignant fungating wounds (MFWs) are cancer-related complications that arise from metastases in advanced cancers. They appear in 5-14% of cancer patients, with higher prevalence in breast (66%) and head and neck (24%) cancers. Novel therapeutic routes for the management of MFWs rely on plant-based treatments, e.g. oxymatrine (OXM), an alkaloid derived from a Chinese plant with anticancer and anti-inflammatory properties. The objective of this work was to assess the potential of polyvinyl alcohol/casein (PVA/CAS) hydrogels to be used as dressings for OXM delivery. CAS can stimulate the immune system, while PVA is one of the most used synthetic polymers in the composition of hydrogels for medical applications. Six different hydrogel formulations were prepared following different procedures: freeze-thawing (FT) and cast drying (CD) for 24 or 48 h, with and without the addition of genipin (GE), a crosslinking agent. The hydrogels were loaded with OXM, and their release behaviour was studied. PVA/CAS-24CD + GE showed the best release profile. After being subjected to sterilisation by high hydrostatic pressure, it was further investigated in terms of physicochemical properties, mechanical characteristics and biocompatibility. Overall, this hydrogel revealed adequate characteristics to be used as a biocompatible medicated dressing for OXM release.