Novel reactive sorbents to sorb, immobilize, and transform malodorous molecules for palliative management of malignant fungating wounds

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Project Summary/Abstract Malignant fungating wounds (MFWs) affect 5% to 14% of advanced cancer patients in the United States. Sadly, the average life expectancy for a person living with MFWs is six to twelve months. Malodor is the most distressing and debilitating symptom of MFWs, causing gagging, vomiting, loss of appetite, and psychological distress, including social withdrawal, social isolation, anxiety, loneliness, and depression. Malodor results from a cocktail of volatile agents that includes acids, polyamines, and sulfur compounds such as dimethyl trisulfide (DMTS). The current methods used to manage malodor are: (a) reducing bioburdens that cause odor, (b) masking the odor, and (c) absorbing the odor (e.g., via charcoal, green tea teabags, cat litter, etc.). However, these strategies offer only limited success and malodor continues to be the worst aspect of MFWs. The goals of advanced cancer patient care should include a palliative approach for symptom management to improve quality of life. To this end, this project will develop a novel reactive sorbent approach to sorb, immobilize, and/or transform malodorous molecules that are generated by MFWs to improve odor management in palliative care. This new strategy has never been reported before. We will selectively oxidize alginate (a natural anionic polymer) to generate covalently bonded aldehyde groups for charcoal coating to form porous amine-reactive sorbents. In this design, the charcoal will sorb polyamines (e.g., putrescine and cadaverine) to reduce their contents, the carboxylic acid groups on the alginate will ionically immobilize the amines through acid/base reactions, and the aldehyde groups will covalently immobilize the amines through the formation of odorless imine structures. Also, we will use chitosan, a natural cationic polymer, to coat benzoyl peroxide (BPO), a mild oxidizer for acne treatment, onto charcoal to form porous acid-/DMTS-reactive sorbents. The charcoal will sorb the acids (e.g., n-butyric, n-valeric, and n-caproic) and DMTS, the chitosan will react with the acids to form odorless salts through acid/base reaction, and the BPO will oxidize the DMTS to transform it into sulfoxide and thiosulfinate derivatives with a much less unpleasant odor. These combined actions are expected to improve the level of odor management significantly. The specific aims of this project are to: (1) fabricate new reactive sorbents, (2) evaluate in vitro the odor control performance of the new reactive sorbents, and (3) evaluate the performance of the new reactive sorbents in a wound-like in vitro model. A unique feature of the reactive sorbents is that they will not only sorb malodorous molecules to reduce the molecule content, but they also will react with the molecules to transform them into non-volatile, odorless (or with a much less unpleasant odor) molecules. The reactive sorbents can be used alone or with current odor-managing strategies for comprehensive odor management. Thus, this work will have a major positive impact on the palliative care of end-of-life cancer patients.