G. Lautner, S.P. Schwendeman, M.E. Meyerhoff
University of Michigan, United States
pp. 5 - 8
Keywords: nitric oxide, PLGA, microsphere, controlled release
In the current work, we encapsulated an S-nitroso species in biodegradable poly(lactic-co-glycolic acid (PLGA) microspheres (with diameter of 20-125 µm) that release nitric oxide (NO) for weeks in a continuous and controlled manner. The rate and duration of NO are tunable by varying the loading and the type of the applied PLGA in the formulation (e.g., acid terminated or ester-capped, lactic-glycolic acid ratio, etc.). The NO release rate also can be tuned to desired levels by use of copper ions or light. The encapsulation of the S-nitroso-N-acetylpenicillamin (SNAP) crystals in the polymer leads to highly stable microparticles that retain their NO release properties, when stored at room temperature in the dark. PLGA-SNAP microspheres can be used for several biomedical applications where the extended and controlled NO release is desired, e.g. in wound healing, since NO has substantial antimicrobial effects and promotes growth of new blood vessels. To prepare a new type of NO releasing wound dressing, we incorporated our PLGA-SNAP microspheres into alginate films (PLGA-SNAP/alginate) that could be used for treatment of chronic wounds (e.g., diabetic ulcers) and skin burns. The PLGA-SNAP/alginate film continuously releases NO at endothelial level over a week period.