Effect of Selected Anionic and Cationic Drugs Affecting the Central Nervous System on Electrical Properties of Phosphatidylcholine Liposomes: Experiment and Theory

Antipsychotics possess anti-glioblastoma activity by disrupting lysosomal function and inhibiting oncogenic signaling by stabilizing PTEN

The repurposing of medications developed for central nervous system (CNS) disorders, possessing favorable safety profiles and blood-brain barrier permeability, represents a promising strategy for identifying new therapies to combat glioblastoma (GBM). In this study, we investigated the anti-GBM activity of specific antipsychotics and antidepressants in vitro and in vivo. Our results demonstrate that these compounds share a common mechanism of action in GBM, disrupting lysosomal function and subsequently inducing lysosomal membrane rupture and cell death. Notably, PTEN intact GBMs possess an increased sensitivity to these compounds. The inhibition of lysosomal function synergized with inhibitors targeting the EGFR-PI3K-Akt pathway, leading to an energetic and antioxidant collapse. These findings provide a foundation for the potential clinical application of CNS drugs in GBM treatment. Additionally, this work offers critical insights into the mechanisms and determinants of cytotoxicity for drugs currently undergoing clinical trials as repurposing agents for various cancers, including Fluoxetine, Sertraline, Thioridazine, Chlorpromazine, and Fluphenazine.

Gelatin as a bioactive nanodelivery system for functional food applications

Gelatin has long been used as an encapsulant agent in the pharmaceutical and biomedical industries because of its low cost, wide availability, biocompatibility, and degradability. However, the exploitation of gelatin for nanodelivery application is not fully achieved in the functional food filed. In this review article, we highlight the latest work being performed for gelatin-based nanocarriers, including polyelectrolyte complexes, nanoemulsions, nanoliposomes, nanogels, and nanofibers. Specifically, we discuss the applications and challenges of these nanocarriers for stabilization and controlled release of bioactive compounds. To achieve better efficacy, gelatin is frequently used in combination with other biomaterials such as polysaccharides. The fabrication and synergistic effects of the newly developed gelatin composite nanocarriers are also present.

The Effect of Selected Flavonoids and Lipoic Acid on Natural and Model Cell Membranes: Langmuir and Microelectrophoretic Methods

The influence of kaempferol (K), myricetin (M) and lipoic acid (LA) on the properties of natural erythrocytes, isolated from animal blood and biological membrane models (monolayers and liposomes) made of phosphatidylcholine (PC), cholesterol (CHOL), and sphingomyelin (SM), CHOL in a ratio of 10:9, was investigated. The Langmuir method, Brewster angle microscopy (BAM) and microelectrophoresis were used. The presented results showed that modification of liposomes with kaempferol, myricetin and lipoic acid caused changes in the surface charge density and the isoelectric point value. Comparing the tested systems, several conclusions were made. (1) The isoelectric point for the DPPC:Chol:M (~2.2) had lower pH values compared to lipoic acid (pH~2.5) and kaempferol (pH~2.6). (2) The isoelectric point for the SM-Chol with myricetin (~3.0) had lower pH values compared to kaempferol (pH~3.4) and lipoic acid (pH~4.7). (3) The surface charge density values for the DPPC:Chol:M system in the range of pH 2-9 showed values from 0.2 to -2.5 × 10^-2 C m^-2. Meanwhile, for the DPPC:Chol:K and DPPC:Chol:LA systems, these values were higher at pH~2 (0.7 × 10^-2 C m^-2 and 0.8 × 10^-2 C m^-2) and lower at pH~9 (-2.1 × 10^-2 C m^-2 and -1.8 × 10^-2 C m^-2), respectively. (4) The surface charge density values for the SM:Chol:M system in the range of pH 2-9 showed values from 0.5 to -2.3 × 10^-2 C m^-2. Meanwhile, for the DPPC:Chol:K and DPPC:Chol:LA systems, these values were higher at pH~2 (0.8 × 10^-2 C m^-2), and lower at pH~9 (-1.0 × 10^-2 C m^-2 and -1.8 × 10^-2 C m^-2), respectively. (5) The surface charge density values for the erythrocytes with myricetin in the range of pH 2-9 showed values from 1.0 to -1.8 × 10^-2 C m^-2. Meanwhile, for the erythrocytes:K and erythrocytes:LA systems, these values, at pH~2, were 1.3 × 10^-2 C m^-2 and 0.8 × 10^-2 C m^-2 and, at pH~9, -1.7 × 10^-2 C m^-2 and -1.0 × 10^-2 C m^-2, respectively.

Interactions between Phosphatidylcholine and Kaempferol or Myristicin: Langmuir Monolayers and Microelectrophoretic Studies

Flavonoid compounds are known for their antibacterial, anti-inflammatory, and anticancer properties. Therefore, they can influence membrane properties that interest us, modifying both their structure and functions. We used kaempferol (K) and myricetin (M) as representatives of this group. We investigated the influence of the abovementioned compounds on model cell membranes' properties (i.e., Langmuir monolayers and liposomes). The basic research methods used in these studies were the Langmuir method with Brewster angle microscopy and microelectrophoresis. The π-A isotherms were registered for the pure components and mixtures of these compounds with phosphatidylcholine (PC) in appropriate volume ratios. Using mathematical equations, we established that kaempferol, myricetin, and the lipids formed complexes at 1:1 ratios. We derived the parameters characterizing the formed complexes, i.e., the surfaces occupied by the complexes and the stability constants of the formed complexes. Using the microelectrophoretic method, we determined the dependence of the lipid membranes' surface charge density as a function of the pH (in the range of 2 to 10) of the electrolyte solution. The presented results indicate that the PC membrane's modification with kaempferol or myricetin affected changes in the surface charge density and isoelectric point values.