The Role of Cell Membranes in Cell Traffic

The cell membrane plays an important role in cell traffic because it functions to secrete various molecules. The selective transport system allows the movement of molecules into or out of the cell compartment. By controlling the movement of substances from one compartment to another, membranes exert a strong influence on metabolic pathways. Cell membranes are composed of proteins and lipids with a very important function in maintaining the rhythm of circulation and cell transport. In addition, the cell membrane also plays a role in maintaining the integrity and relationship, and communication of cells.

Linoleic acid as corpse recognition signal in a social aphid

Social insect colonies constantly produce dead insects, which cause sanitary problems and potentially foster deadly pathogens and parasites. Hence, many social insects have evolved a variety of hygienic behaviors to remove cadavers from the colonies. To that end, they have to discriminate dead insects from live ones, where chemical cues should play important roles. In ants, bees and termites, such corpse recognition signals, also referred to as “death pheromones” or “necromones”, have been identified as fatty acids, specifically oleic acid and/or linoleic acid. Meanwhile, there has been no such report on social aphids. Here we attempted to identify the “death pheromone” of a gall-forming social aphid with second instar soldiers, Tuberaphis styraci, by making use of an artificial diet rearing system developed for this species. On the artificial diet plates, soldiers exhibited the typical cleaning behavior, pushing colony wastes with their heads continuously, against dead aphids but not against live aphids. GC-MS and GC-FID analyses revealed a remarkable increase of linoleic acid on the body surface of the dead aphids in comparison with the live aphids. When glass beads coated with either linoleic acid or body surface extract of the dead aphids were placed on the artificial diet plates, soldiers exhibited the cleaning behavior against the glass beads. A series of behavioral assays showed that (i) soldiers exhibit the cleaning behavior more frequently than non-soldiers, (ii) young soldiers perform the cleaning behavior more frequently than old soldiers, and (iii) the higher the concentration of linoleic acid is, the more active cleaning behavior is induced. Analysis of the lipids extracted from the aphids revealed that linoleic acid is mainly derived from phospholipids that constitute the cell membranes. In conclusion, we identified linoleic acid as the corpse recognition factor of the social aphid T. styraci. The commonality of the death pheromones across the divergent social insect groups (Hymenoptera, Blattodea and Hemiptera) highlights that these unsaturated fatty acids are generally produced by enzymatic autolysis of cell membranes after death and therefore amenable to utilization as a reliable signal of dead insects.

Construction of biomimetic-responsive nanocarriers and their applications in tumor targeting

Backgroud: At present, the tumor is still the leading cause of death. Biomimetic nanocarriers for precision cancer therapy are attracting increasing attention. Nanocarriers with a good biocompatible surface could reduce the recognition and elimination of nanoparticles as foreign substances by the immune system, offer specific targeting, and improve the efficacy of precision medicine for tumors, thereby providing outstanding prospects for application in cancer therapy. In particular, cell membrane biomimetic camouflaged nanocarriers have become a research hotspot because of their excellent biocompatibility, prolonged circulation in the blood, and tumor targeting. Objective: To summarize the biological targeting mechanisms of different cell membrane-encapsulated nanocarriers in cancer therapy. In this article, the characteristics, application, and stage of progress of bionic encapsulated nanocarriers for different cell membranes are discussed, as are the field’s developmental prospects. Method: The findings on the characteristics of bionic encapsulated nanocarriers for different cell membranes and tumor treatment have been analyzed and summarized. Results: Biomimetic nanosystems based on various natural cell and hybrid cell membranes have been shown to efficiently control targeted drug delivery systems. They can reduce immune system clearance, prolong blood circulation time, and improve drug loading and targeting, thereby enhancing the diagnosis and treatment of tumors and reducing the spread of CTCs. Conclusion: ：With advances in the development of biomimetic nanocarrier DDSs, novel ideas for tumor treatment and drug delivery have been developed. However, there are still some problems in biomimetic nanosystems. Therefore, it needs to be optimized through further research, from the laboratory to the clinic for the benefit of a wide range of patients.

High Sensitivity Detection of Tumor Cells in Biological Samples using Multivalent Aptamer Strand Displacement Strategy

Monitoring the cell surface-expressed nucleolin facilitates early cancer diagnosis. Herein, we developed multivalent aptamer displacement strand duplex strategy on the cell membranes utilizing a multi-receptor co-recognition design for improving sensitivity...

Effect of Polycation Nanostructures on Cell Membrane Permeability and Toxicity

The interaction of nanometric synthetic materials with cell membranes is one of the key factors determining their possible cytotoxicity. This work investigated the interaction of polycation nanostructures with lipid and...