Abstract
As a skin safety in vitro test, the effects of poly (aspartic acid-co-lactic acid) encapsulated pro-vitamin nanospheres with the average diameter from 195 to 210nm on tumor invasion through the reconstituted basement membrane were evaluated with mouse melanoma cells B16BL6. The nanospheres containing pro-vitamin showed the inhibitory action against tumor invasion. However, the inhibitory effect on tumor-invasion was the highest for empty nanospheres without pro-vitamin and was enhanced with the increase in nanosphere concentration. This may be explained through the ionic interferences resulting from the anionic property of carboxyl group in aspartic acid. The poly-anions can interact or chelate with Zn ions of MMP intermediates instead of H2O molecules through a strong electrostatic force, suppressing the conversion of pro-MMP produced by the melanoma cells to activated MMP which lyses the basement membrane to form the tumor invasion routes. Therefore, the nanospheres are suggested to be safe material for skin application.
