Biomimetic hierarchical nanofibrous surfaces inspired by superhydrophobic lotus leaf structure for preventing tissue adhesions

Undesirable tissue adhesions remain one of the most common and dreaded postoperative complications. Biocompatible nanofibrous mats with antiadhesive surfaces represent a promising barrier method for preventing the formation of adhesions. The material developed in this work was inspired by the natural superhydrophobic lotus leaf nanostructure, which was mimicked by a unique combination of needleless electrospraying and electrospinning technology of poly-ε-caprolactone (PCL). The surface hydrophobicity of electrosprayed nanodroplets was further enhanced by cold plasma modification using the chemical vapor deposition (CVD) method with hexamethyldisiloxane (HMDSO). The treatment led to a successful decrease in surface wettability of our samples. Morphology (scanning electron microscopy), wettability (contact angle) and chemical composition (FTIR analysis) were observed for a period of six months to track possible changes; the obtained results verified the presence of HMDSO during the whole time period. Cytocompatibility was confirmed in vitro with 3T3 mouse fibroblasts according to the norm ISO 10993-5. Cell adhesion and proliferation were assessed in vitro by metabolic MTT assay and fluorescence microscopy after 4, 7, and 14 days. Antiadhesive behaviour was confirmed by atomic force microscopy and ex vivo by peel test 90° with intestinal tissue, the final structure has a great potential to reduce postoperative tissue adhesions

Red Cell Membrane Remodeling in Sickle Cell Anemia Sequestration of Membrane Lipids and Proteins in Heinz Bodies

In red cells from patients with sickle cell anemia, hemoglobin S denatures and forms Heinz bodies. Binding of Heinz bodies to the inner surface of the sickle cell membrane promotes clustering and colocalization of the membrane protein band 3, outer surface-bound autologous IgG and, to some extent, the membrane proteins glycophorin and ankyrin. Loss of transbilayer lipid asymmetry is also found in certain populations of sickle red cells. The lateral distribution of sickle cell membrane lipids has not been examined, however. In this report, we examine by fluorescence microscopy the incorporation and distribution of the fluorescent phospholipid analogues 7-nitro-2,1,3-benzoxadiazol-4-yl (NBD)-phosphatidylserine and NBD-phosphatidylcholine in sickle red cells. Both phospholipid analogues ar

Differential control of band 3 lateral and rotational mobility in intact red cells

Measurements of integral membrane protein lateral mobility and rotational mobility have been separately used to investigate dynamic protein--protein and protein-lipid interactions that underlie plasma membrane structure and function. In model bilayer membranes, the mobilities of reconstituted proteins depend on the size of the diffusing molecule and the viscosity of the lipid bilayer. There are no direct tests, however, of the relationship between mechanisms that control protein lateral mobility and rotational mobility in intact biological membranes. We have measured the lateral and rotational mobility of band 3 in spectrin-deficient red blood cells from patients with hereditary spherocytosis and hereditary pyropoikilocytosis. Our data suggest that band 3 lateral mobility is regulated by the spectrin content of the red cell membrane. In contrast, band 3 rotational mobility is unaffected by changes in spectrin content. Band 3 lateral mobility and rotational mobility must therefore be controlled by different molecular mechanisms