Use of giant unilamellar lipid vesicles as antioxidant carriers in in vitro culture medium of bovine embryos

Development and validation of a minimally invasive protocol for assessing oxidative stress markers in exfoliated oral cells

OBJECTIVES

This study aimed to develop and validate a minimally invasive protocol for characterizing oxidative stress markers in exfoliated oral cells.

MATERIALS AND METHODS

Exfoliated oral cells were collected from healthy volunteers. The protocol included the utilization of specific fluorescent probes to measure intracellular reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm) and reduced glutathione (GSH). Cells from each volunteer were divided into the positive and negative control groups, which were, respectively, exposed or not to hydrogen peroxide (H2 O2 ) aiming to induce the oxidative stress. Measurements of cell fluorescence were performed using a microscope equipped with epifluorescence.

RESULTS

The results showed that cells exposed to H2 O2 exhibited significantly higher intracellular expression of ROS compared to unexposed cells (positive control: 3851.25 ± 1227.0 vs, negative control: 1106.07 ± 249.6; p = 0.0338). On the contrary, cells exposed to H2 O2 displayed decreased expression of ΔΨm (p = 0.0226) and GSH (p = 0.0289) when compared to the negative control group (ΔΨm positive control: 14634.39 ± 1529.0 vs, negative control: 18897.60 ± 2338.0; and GSH positive control: 9011.08 ± 1900.0 vs, negative control: 15901.79 ± 2745.0).

CONCLUSIONS

The developed protocol proved to be effective in detecting and quantifying oxidative stress biomarkers, such as ROS, ΔΨm and GSH, in exfoliated oral cells. This minimally invasive approach offers a promising method to assess oxidative stress expression and may be clinically relevant in the evaluation of oral diseases associated with oxidative stress.

Osmotic Pressure Enables High-Yield Assembly of Giant Vesicles in Solutions of Physiological Ionic Strengths

Giant unilamellar vesicles (GUVs) are micrometer-scale minimal cellular mimics that are useful for bottom-up synthetic biology and drug delivery. Unlike assembly in low-salt solutions, assembly of GUVs in solutions with ionic concentrations of 100-150 mM Na/KCl (salty solutions) is challenging. Chemical compounds deposited on the substrate or incorporated into the lipid mixture could assist in the assembly of GUVs. Here, we investigate quantitatively the effects of temperature and chemical identity of six polymeric compounds and one small molecule compound on the molar yields of GUVs composed of three different lipid mixtures using high-resolution confocal microscopy and large data set image analysis. All the polymers moderately increased the yields of GUVs either at 22 or 37 °C, whereas the small molecule compound was ineffective. Low-gelling temperature agarose is the singular compound that consistently produces yields of GUVs of greater than 10%. We propose a free energy model of budding to explain the effects of polymers in assisting the assembly of GUVs. The osmotic pressure exerted on the membranes by the dissolved polymer balances the increased adhesion between the membranes, thus reducing the free energy for bud formation. Data obtained by modulating the ionic strength and ion valency of the solution shows that the evolution of the yield of GUVs supports our model's prediction. In addition, polymer-specific interactions with the substrate and the lipid mixture affects yields. The uncovered mechanistic insights provide a quantitative experimental and theoretical framework to guide future studies. Additionally, this work shows a facile means for obtaining GUVs in solutions of physiological ionic strengths.

Neurogenic Hypertension, the Blood-Brain Barrier, and the Potential Role of Targeted Nanotherapeutics

Hypertension is a major health concern globally. Elevated blood pressure, initiated and maintained by the brain, is defined as neurogenic hypertension (NH), which accounts for nearly half of all hypertension cases. A significant increase in angiotensin II-mediated sympathetic nervous system activity within the brain is known to be the key driving force behind NH. Blood pressure control in NH has been demonstrated through intracerebrovascular injection of agents that reduce the sympathetic influence on cardiac functions. However, traditional antihypertensive agents lack effective brain permeation, making NH management extremely challenging. Therefore, developing strategies that allow brain-targeted delivery of antihypertensives at the therapeutic level is crucial. Targeting nanotherapeutics have become popular in delivering therapeutics to hard-to-reach regions of the body, including the brain. Despite the frequent use of nanotherapeutics in other pathological conditions such as cancer, their use in hypertension has received very little attention. This review discusses the underlying pathophysiology and current management strategies for NH, as well as the potential role of targeted therapeutics in improving current treatment strategies.

Design of double functionalized carbon nanotube for amphotericin B and genetic material delivery

In the present work, single wall carbon nanotubes (SWCNT) were successively functionalized with phospholipid DSPE-PEG carboxylic acid, and then, with ethylenediamine (EDA), to obtain double functionalized single wall carbon nanotube (DFSWCNT). Then, DFSWCNT was applied as a carrier for delivering amphotericin B (Amb) and EGFP plasmid. FSWCNT's concentration obtained via UV-visible analysis was 0.99 mg/mL. The TGA analysis results provided the lost weights of DSPE-PEG-COOH, EDA, Amb and SWCNT impurities. XPS results showed that carbon atoms' percentage decreased during the functionalization processes from 97.2% (SWCNT) to 76.4% (FSWCNT) and 69.9% (DFSWNCT). Additionally, the oxygen atoms' percentage increased from 2.3% (SWCNT) to 21% and 22.5% for FSWCNT and DFSWCNT, respectively. New bonds such as C-N and N-C=O appeared in the synthesized nanocarrier. The I_G/I_D ratio in Raman analysis decreased from 7.15 (SWCNT) to 4.08 (FSWCNT). The amount of Amb released to phosphate buffer saline medium was about 33% at pH = 5.5 and 75% at pH = 7.4 after 48 h. CCK8 results confirmed that the toxicity of functionalized SWCNT had decreased. In a 2:1 ratio of DFSWCNT/EGFP plasmid, the cell viability (87%) and live transfected cells (56%) were at their maximum values. The results indicate that carbon nanotubes have the potential to be applied as drug/gene delivery systems with outstanding properties such as high loading capacity and easy penetration to cell membrane.