Cytotoxicity screening of ALG-MA-DA and GEL-MA-DA sealant materials without (non-polymerized) or following photocrosslinking (polymerized) demonstrate no siginificant cytotoxicity for human bronchial epithelial (HBE) or transformed alveolar epithelial cells (A549), human pleural mesothelial cells (HPM), or human lung fibroblasts (HLF). (a) In contrast, both the photo-initiator compound and oxidant alone each had significant toxicity on HBE, HPM, and HLF cells. (b) Data is presented as means + SD (n = 4 for each cell line) of similar results from one of two separate experiments. *** p < 0.001.