Fig 4.

(a, b) Macropinocytosis of MBNs–NH₂ into rDPSCs after 4 hours of incubation by TEM images and Ca and Si ion concentrations from total cells (c) or cultured odontogenic supplemental media (OM) (d) by ICP-AES. Low-magnification (a, ×8,000) and high-magnification (b, ×20,000, black dot box from (a)) TEM images of rDPSCs after treatment with MBNs–NH₂ (50 μg/mL of 10⁵ cells) for 4 hours. Macropinocytosis with membrane ruffles was only observed without clathrin or caveolae-coated membrane or vesicle. Black arrow shows membrane ruffles, a typical characteristic of macropinocytosis; black asterisks indicate the intracellular distribution of MBNs–NH₂ in endosomes. Significant increases in Si ion concentration from total cells were detected at 12, 24, 48, and 72 hours in the MBNs–NH₂–treated rDPSCs compared to control (without [w/o] treatment), while Ca ion concentrations were significantly detected at 4 and 12 h of incubation (p<0.05). According to the preliminary results for cell numbers at 4, 12, 24, 48, or 72 hours of incubation under OM with or without MBNs–NH_2, there was no significant difference. * Statistically significant difference in MBNs–NH₂–treated group compared with the untreated group (p<0.05).