2 research outputs found
Aggregation Behavior of the Template-Removed 5,10,15,20-Tetrakis(4-sulfonatophenyl)porphyrin Chiral Array Directed by Poly(ethylene glycol)-<i>block</i>-poly(l‑lysine)
Complexation between 5,10,15,20-tetrakisÂ(4-sulfonatophenyl)Âporphyrin
(TPPS) and polyÂ(ethylene glycol)-<i>block-</i>polyÂ(l-lysine) (PEG-<i>b</i>-PLL) was performed via electrostatic
interaction. Two kinds of primary arrays of TPPS with different supramolecular
chirality induced by PLL were obtained in the resultant complex by
inverting the mixing procedure of the two components. These arrays
could be displaced by polyÂ(sodium-<i>p</i>-styrenesulfonate)
(PSS) from the chiral PLL template through competitive electrostatic
complexation, and then PSS formed a polyion complex micelle with PEG-<i>b</i>-PLL. The template-removed TPPS arrays preserved their
induced chirality and served as primary subunits for the secondary
aggregation of TPPS. The morphology of the secondary aggregates was
strongly dependent upon the asymmetric primary supramolecular arrangement
of TPPS. The rodlike nanostructure that was ∼200 nm in length
was composed of the primary arrays that showed opposite exciton chirality
between the J- and H-bands. In contrast, the micrometer-sized fibrils
observed were composed of the arrays with the same exciton chirality
at the J- and H-bands
Assessing the Redox Toxicity of 2D Nanosheets Based on Their Redox Effect on Cytochrome <i>c</i> in Microchannels
2D nanosheets (NSs) have been widely
used in drug-related applications.
However, a comprehensive investigation into the cytotoxicity mechanism
linked to the redox activity is lacking. In this study, with cytochrome c (Cyt c) as the model biospecies, the
cytotoxicity of 2D NSs was evaluated systematically based on their
redox effect with microfluidic techniques. The interface interaction,
dissolution, and redox effect of 2D NSs on Cyt c were
monitored with pulsed streaming potential (SP) measurement and capillary
electrophoresis (CE). The relationship between the redox activity
of 2D NSs and the function of Cyt c was evaluated in vitro with Hela cells. The results indicated that the
dissolution and redox activity of 2D NSs can be simultaneously monitored
with CE under weak interface interactions and at low sample volumes.
Both WS2 NSs and MoS2 NSs can reduce Cyt c without significant dissolution, with reduction rates
measured at 6.24 × 10–5 M for WS2 NSs and 3.76 × 10–5 M for MoS2 NSs. Furthermore, exposure to 2D NSs exhibited heightened reducibility,
which prompted more pronounced alterations associated with Cyt c dysfunction, encompassing ATP synthesis, modifications
in mitochondrial membrane potential, and increased reactive oxygen
species production. These observations suggest a positive correlation
between the redox activity of 2D NSs and their redox toxicity in Hela
cells. These findings provide valuable insight into the redox properties
of 2D NSs regarding cytotoxicity and offer the possibility to modify
the 2D NSs to reduce their redox toxicity for clinical applications