Controlled Adhesion of HUVEC on Polyelectrolyte Multilayers by Regulation of Coating Conditions

Effects of polyallylamine-coated nanoparticles on the optical and photochemical properties of rose bengal

BACKGROUND

Inasmuch as optical and photochemical properties of a photosensitizer can be modified upon association with the nanoparticle (NP), we wondered whether the effectiveness of phototherapeutic rose bengal (RB) was affected upon tethering to the sodium lanthanide fluoride NP with an outer polyallylamine (PAH) coat.

METHODS

RB molecules were electrostatically bound to the NaYF 4 :Gd 3+ :Nd 3+ NPs with inner silica and outer PAH coats. The products were analyzed for their size, shape and zeta potential using transmission electron microscopy and dynamic light scattering instrument. Ultraviolet-visible absorption spectrometry and fluorescence spectrometry were used to examine the spectral properties. Photodynamic effect in terms of singlet oxygen generation was quantitatively determined using the indicator 1,3-diphenylisobenzofuran (DPBF). Photocytotoxicity mediated by NP-bound RB was tested using A549 cells (Student's t test was used for statistical evaluation).

RESULTS

NP-bound RB had the major absorbance peak at 561 nm, in comparison with 549 nm for free RB, accompanied with a significant decrease in absorptivity. The molar extinction coefficient becomes 36 000 M -1 cm -1 , only ~35% of that for free RB. Fluorescence spectral analyses showed a paradoxical decrease in the emission with higher NP concentrations even at very low dilutions. Most importantly, the association of RB with these NPs drastically increased its singlet oxygen production upon irradiation. The interaction of RB with PAH coat could partly account for this enhancement, given our finding that PAH in solution also caused a drastic rise in DPBF reactivity by free RB. These NPs exhibited strong photocytotoxic effects, and their promise in photodynamic therapy was addressed.

CONCLUSION

Our findings provide evidence that the PAH coat plays a key role in enhanced biological activities of RB delivered via NPs, including the increase in singlet oxygen production and photocytotoxic effects.

Role of Exosomes Derived from Secretome Human Umbilical Vein Endothelial Cells (Exo-HUVEC) as Anti-Apoptotic, Anti-Oxidant, and Increasing Fibroblast Migration in Photoaging Skin Models

Background: Prolonged skin exposure to ultraviolet light rays leads to photoaging, which is characterized molecularly by an increase in reactive oxygen species (ROS), cell apoptosis, and a decrease in collagen. Photoaging therapy has been a challenge until recently. Fibroblasts exposed to ultraviolet B (UVB) light proved to be a good model for photoaging skin. They are also the primary dermal cells that stimulate collagen production and extracellular matrix (ECM), which contribute to skin aging. Exo-HUVEC is rich in growth factors, cytokines, and miRNAs, and they all play a vital role in cell-to-cell communication. The migration of fibroblasts is crucial for the development, repair, and regeneration of skin tissue during the repair of skin aging. Objective: An in vitro experimental study was conducted to analyze the effect of Exo-HUVEC on oxidative stress levels, cell apoptosis, and fibroblast migration rate after UVB ray exposure on fibroblasts. Methods: The fibroblast cultures were divided into five groups, including one without UVB exposure, one with UVB exposure, and one with UVB+Exo-HUVEC exposure at 0.1%, 0.5%, and 1%, respectively. Oxidative stress levels were measured using the ELISA test for malondialdehyde (MDA). Furthermore, flow cytometry was used to measure apoptosis using PI/Annexin markers, while a scratch assay examination was used to measure fibroblast migration rate using imaging readings. Results: There were significant differences in the levels of MDA, PI/Annexin, and the rate of fibroblast migration between the UVB-irradiated control group and the Exo-HUVEC treatment group (p<0.001). Conclusion: Exo-HUVEC is a marker of photoaging improvement, which has anti-apoptotic effects and reduces oxidative stress, as well as increases fibroblast migration rate.