Properties and cellular uptake of photo-triggered mixed metallosurfactant vesicles intended for controlled CO delivery in gas therapy

The scientific relevance of carbon monoxide has increased since it was discovered that it is a gasotransmitter involved in several biological processes. This fact stimulated research to find a secure and targeted delive r y and lead to the synthesis of CO-releasing molecules. In this paper we present a vesicular CO deliver y system triggered by light composed of a synthetized metallosurfactant (TCOL10) with two long carbon chains and a molybdenum-carbonyl complex. We studied the characteristics of mixed TCOL10/phosphatidylcholine metallosomes of different sizes. Vesicles from 80 to 800 nm in diameter are mainly unilamellar, do not disaggregate upon dilution, in the dark are physically and chemically stable at 4 degrees C for at least one month, and exhibit a lag phase of about 4 days before they show a spontaneous CO release at 37 degrees C. Internalization of metallosomes by cells was studied as function of the incubation time, and vesicle concentration and size. Results show that large vesicles are more efficiently internalized than the smaller ones in terms of the percentage of cells that show TCOL10 and the amount of drug that they take up. On balance, TCOL10 metallosomes constitute a promisin g and viable approach for efficient delivery of CO to biological systems.

Automated summary

The discovery that carbon monoxide is a gasotransmitter involved in biological processes has increased its scientific relevance. This led to the synthesis of CO-releasing molecules for secure and targeted delivery. In this study, a vesicular CO delivery system composed of a metallosurfactant (TCOL10) and a molybdenum-carbonyl complex triggered by light was presented. The metallosomes showed stable characteristics and a lag phase before spontaneous CO release, and large vesicles were more efficiently internalized by cells compared to smaller ones.