Similar observations were also made by Stopar et al . who investigated the enzymatic cleavage of the DO scaffold by several restriction endonucleases at their respective recognition sites . [ 114 ] They found that these sites can be either active or strongly resistant toward enzymatic cleavage , d epending on the local mechanical and topological properties in the vicinity of the individual site . [ 114,115 ] Theb ulk of these data suggests that DN can be rationally designed for increased serum stability and cell uptake , f or instance , b ym aking them mechanically very rigid to suppress nuclease binding . However , t he desired performance of ag iven DN depends not only on its stability and uptake but also on other aspects such as drug loading efficiency and release kinetics , w hich are affected by the same design factors . I ndividual design - related properties will thus have to be weighed against each other , favoring , f or instance , e fficient drug intercalation over serum stability .