Development of carbon monoxide-releasing molecules conjugated to polysaccharides (glyco-CORMs) for delivering CO during obesity.

Metal carbonyls have been developed as carbon monoxide-releasing molecules (CO-RMs) to deliver CO for therapeutic purposes. The manganese-based CORM-401 has been recently reported to exert beneficial effects in obese animals by reducing body weight gain, improving glucose metabolism and reprogramming adipose tissue towards a healthy phenotype. Here, we report on the synthesis and characterization of glyco-CORMs, obtained by grafting manganese carbonyls on dextrans (70 and 40 kDa), based on the fact that polysaccharides facilitate the targeting of drugs to adipose tissue. We found that glyco-CORMs efficiently deliver CO to cells in vitro with higher CO accumulation in adipocytes compared to other cell types. Oral administration of two selected glyco-CORMs (5b and 6b) resulted in CO accumulation in various organs, including adipose tissue. In addition, glyco-CORM 6b administered for eight weeks elicited anti-obesity and positive metabolic effects in mice fed a high fat diet. Our study highlights the feasibility of creating carriers with multiple functionalized CO-RMs.