Fig. 12
Cytotoxicity assessment of DOX using dual-crosslinked Alg-MA sub-microspheres as chemotherapeutic delivery vehicles. a Chemical structure of dual-crosslinked Alg-MA hydrogel networks. b Schematic representation of microsphere fabrication techniques. Premixing of Alg-MA solutions with or without DOX was followed by water/oil emulsion at room temperature generated microspheres. Alg-MA sub-microspheres were photo-crosslinked upon the exposure to visible or UV light, respectively, and further dual-crosslinked in the presence of 1 M CaCl2. c MTT-based assay of DOX loaded dual-crosslinked Alg-MA sub-microspheres to quantify the cell proliferation over a 5-day period. A549 activity was recorded as the mitochondrial activity and normalized to the non-modified cell controls. Various formulations and concentrations (10–100 μg/mL) of the sub-microspheres were assessed: green photo-crosslinked (Green), green + Ca2+ dual-crosslinked (Green+C), UV photo-crosslinked (UV), UV + Ca2+ dual-crosslinked (UV + C). DOX was added exogenously (Free DOX) to the cell culture medium at the various concentrations to test the effects of the intracellular versus extracellular DOX delivery [107]. Fenn, S.L., et al., Dual-cross-linked methacrylated alginate sub-microspheres for intracellular chemotherapeutic delivery. ACS applied materials & interfaces. 2016, 8(28):17775–17,783, Copyright (2020)