Red blood cell membrane nanoparticles for tumor phototherapy.

Non-invasive phototherapy includes photodynamic therapy (PDT) and photothermal therapy (PTT), and has garnered special interest in anti-tumor therapy. However, traditional photosensitizers or photothermal agents are faced with major challenges, including easy recognition by immune system, rapid clearance from blood circulation, and low accumulation in target sites. Combining the characteristics of natural cell membrane with the characteristics of photosensitizer or photothermal agent is an important technology to achieve the ideal therapeutic effect of cancer. Red cell membrane (RBMs) coated can disguise phototherapy agents as endogenous substances, thus constructing a new nano bionic therapeutic platform, resisting blood clearance and prolonging circulation time. At present, a variety of phototherapy agents based on Nano-RBMs have been isolated or designed. In this review, firstly, the basic principles of Nano-RBMs and phototherapy are expounded respectively. Then, the latest progress of Nano-RBMs for PDT, PTT and PDT/PTT applications in recent five years has been introduced respectively. Finally, the problems and challenges of Nano-RBMs in the field of phototherapy are put forward.

Alteration of erythrocyte membrane polyunsaturated fatty acids in preterm newborns with retinopathy of prematurity.

Extremely preterm infants are at high risk for retinopathy of prematurity (ROP), a potentially blinding disease characterized by abnormalities in retinal vascularization. Whereas animal studies revealed that n-3 polyunsaturated fatty acids (PUFAs) may be of benefit in preventing ROP, human studies conducted on preterm infants during the 1st weeks of life showed no association between blood n-3 PUFA bioavailability and ROP incidence and/or severity, probably because of the influence of nutrition on the lipid status of infants. In the OmegaROP prospective cohort study, we characterized the erythrocyte concentrations of PUFAs in preterm infants aged less than 29 weeks gestational age (GA) without any nutritional influence. We show that GA is positively associated with the erythrocyte n-6 to n-3 PUFA ratio, and particularly with the ratio of arachidonic acid (AA) to docosahexaenoic acid (DHA), in infants with ROP. A time-dependent accumulation of AA at the expense of DHA seems to occur in utero in erythrocytes of preterm infants who will develop ROP, thus reinforcing previous data on the beneficial properties of DHA on this disease. In addition, preliminary data on maternal erythrocyte membrane lipid concentrations suggest modifications in placental transfer of fatty acids. Documenting the erythrocyte AA to DHA ratio at birth in larger cohorts might be useful to set up new prognostic factors for ROP.

POLYPHENOL CONTENT AND BIOACTIVITY OF SASKATOON (AMELANCHIER ALNIFOLIA NUTT.) LEAVES AND BERRIES.

The studies were designed to determine the polyphenolic composition and biological activity of extracts from fruits (SFE) and leaves (SLE) of Saskatoon (Amelanchier alnifolia Nutt.) in relation to erythrocyte membranes. A detailed quantitative and qualitative analysis of extracts was conducted, using the chro- matographic (UPLC-DAD, UPLC-ESI-MS) and spectrophotometric (Folin-Ciocalteu) methods. The biological activity of the extracts was investigated in relation to erythrocytes and isolated membranes of erythrocytes by using spectrophotometric, fluorimetric and microscopic methods and determined on the basis of hemolytic and antioxidant activity of the extracts and their impact on physical properties of the membrane such as: osmotic resistance, shape of erythrocytes, packing order of the polar head of lipids and fluidity of the membrane. The results showed that the tested extracts are rich sources of polyphenols, primarily from the group of flavonoids; in leaves dominating flavonols and anthocyanins in fruits. The SFE and SLE extracts to varying degree modify the physical properties of the erythrocyte membrane, causing formation of echinocytes, an increase in osmotic resistance and changes in the polar part of the membrane. Furthermore, the substances markedly protect erythrocytes and their membranes against oxidation induced by different physico-chemical factors. The findings indicate that the polyphenolic compounds contained in extracts of Saskatoon do not destroy biological membranes but effectively protect them against oxidation by way of interacting with the membrane surface. The extracts could effectively protect the organism and food products from the harmful effects of free radicals.

Dietary ω-3 fatty acids protect against vasculopathy in a transgenic mouse model of sickle cell disease.

The anemia of sickle cell disease is associated with a severe inflammatory vasculopathy and endothelial dysfunction, which leads to painful and life-threatening clinical complications. Growing evidence supports the anti-inflammatory properties of ω-3 fatty acids in clinical models of endothelial dysfunction. Promising but limited studies show potential therapeutic effects of ω-3 fatty acid supplementation in sickle cell disease. Here, we treated humanized healthy and sickle cell mice for 6 weeks with ω-3 fatty acid diet (fish-oil diet). We found that a ω-3 fatty acid diet: (i) normalizes red cell membrane ω-6/ω-3 ratio; (ii) reduces neutrophil count; (iii) decreases endothelial activation by targeting endothelin-1 and (iv) improves left ventricular outflow tract dimensions. In a hypoxia-reoxygenation model of acute vaso-occlusive crisis, a ω-3 fatty acid diet reduced systemic and local inflammation and protected against sickle cell-related end-organ injury. Using isolated aortas from sickle cell mice exposed to hypoxia-reoxygenation, we demonstrated a direct impact of a ω-3 fatty acid diet on vascular activation, inflammation, and anti-oxidant systems. Our data provide the rationale for ω-3 dietary supplementation as a therapeutic intervention to reduce vascular dysfunction in sickle cell disease.

Dietary supplementation with docosahexanoic acid (DHA) increases red blood cell membrane flexibility in mice with sickle cell disease.

Humans and mice with sickle cell disease (SCD) have rigid red blood cells (RBCs). Omega-3 fatty acids, such as docosahexanoic acid (DHA), may influence RBC deformability via incorporation into the RBC membrane. In this study, sickle cell (SS) mice were fed natural ingredient rodent diets supplemented with 3% DHA (DHA diet) or a control diet matched in total fat (CTRL diet). After 8weeks of feeding, we examined the RBCs for: 1) stiffness, as measured by atomic force microscopy; 2) deformability, as measured by ektacytometry; and 3) percent irreversibly sickled RBCs on peripheral blood smears. Using atomic force microscopy, it is found that stiffness is increased and deformability decreased in RBCs from SS mice fed CTRL diet compared to wild-type mice. In contrast, RBCs from SS mice fed DHA diet had markedly decreased stiffness and increased deformability compared to RBCs from SS mice fed CTRL diet. Furthermore, examination of peripheral blood smears revealed less irreversibly sickled RBCs in SS mice fed DHA diet as compared to CTRL diet. In summary, our findings indicate that DHA supplementation improves RBC flexibility and reduces irreversibly sickled cells by 40% in SS mice. These results point to potential therapeutic benefits of dietary omega-3 fatty acids in SCD.

Altered erythrocyte membrane fatty acid profile in typical Rett syndrome: effects of omega-3 polyunsaturated fatty acid supplementation.

This study mainly aims at examining the erythrocyte membrane fatty acid (FAs) profile in Rett syndrome (RTT), a genetically determined neurodevelopmental disease. Early reports suggest a beneficial effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) on disease severity in RTT. A total of 24 RTT patients were assigned to ω-3 PUFAs-containing fish oil for 12 months in a randomized controlled study (average DHA and EPA doses of 72.9, and 117.1mg/kgb.w./day, respectively). A distinctly altered FAs profile was detectable in RTT, with deficient ω-6 PUFAs, increased saturated FAs and reduced trans 20:4 FAs. FAs changes were found to be related to redox imbalance, subclinical inflammation, and decreased bone density. Supplementation with ω-3 PUFAs led to improved ω-6/ω-3 ratio and serum plasma lipid profile, decreased PUFAs peroxidation end-products, normalization of biochemical markers of inflammation, and reduction of bone hypodensity as compared to the untreated RTT group. Our data indicate that a significant FAs abnormality is detectable in the RTT erythrocyte membranes and is partially rescued by ω-3 PUFAs.

Blood doping: potential of blood and urine sampling to detect autologous transfusion.

The collection of blood, its storage as red blood cell (RBC) concentrates and its reinjection is prohibited; until now, the practice cannot be reliably detected. A recent innovation-the haematological module of the athlete's biological passport-can provide authorities with indications towards autologous blood transfusion. In situations where a given athlete has been exposed to altitude, heat stress, sickness, etc, additional evidence may be needed to establish beyond any reasonable doubt that a blood transfusion may actually have occurred. Additional evidence may be obtained from at least three different approaches using parameters related to blood and urine matrices.Genomics applied to mRNA or miRNA is one of the most promising analytical tools. Proteomics of changes associated with RBC membranes may reveal the presence of cells stored for some time, as can an abnormal pattern of size distribution of aged cells. In urine, high concentrations of metabolites of plasticisers originating from the blood storing bags strongly suggest a recent blood transfusion. We emphasise the usefulness of simultaneously obtaining and then analysing blood and urine for complementary evidence of autologous blood transfusion ('blood doping').

Anti-inflammatory, anti-lipid peroxidative, antioxidant and membrane stabilizing activities of hydroalcoholic extract of Terminalia chebula fruits.

CONTEXT: Arthritis is inflammation of one or more joints. Terminalia chebula Retz. (Combretaceae) fruit is mentioned in Ayurveda as useful in treating arthritic disorders. OBJECTIVE: This work was undertaken to evaluate the anti-inflammatory, antioxidant, anti-lipid peroxidative and membrane-stabilizing effects of hydroalcoholic extract of Terminalia chebula fruits and also to establish a possible association between them. MATERIALS AND METHODS: In vivo anti-inflammatory activity of T. chebula fruit extract at different doses ranged from 50 to 500 mg/kg, p.o. was evaluated against carrageenin-induced inflammation in rats. Human erythrocyte hemolytic assay was used for in vitro anti-inflammatory activity testing with 50 to 500 µg/ml fruit extract. Antioxidant potential of test fruit extract (10 to 100 µg/ml) was evaluated using TBARS and DPPH methods. The fruit extract was standardized for total phenolic content using Folin-Ciocalteu method. RESULTS: The standardized extract at 250 mg/kg, p.o. dose caused 69.96% reduction in carrageenin-induced rat paw edema and demonstrated 96.72% protective effect on human RBC membrane stability. Besides, T. chebula fruit extract significantly reduced the in vivo formation of TBARS in carrageenin-induced rat liver with IC50 94.96 mg/kg, p.o. and also in vitro radical scavenging activities in DPPH assay method with IC50 42.14 µg/ml. The standardized extract contains phenolics 118.5 mg gallic acid equivalent/g of extract. DISCUSSION AND CONCLUSION: These promising findings support the traditional use of T. chebula fruits in the treatment of arthritic disorders and suggest that radical quenching may be one of the mechanisms for its anti-inflammatory activity.

Mediterranean-style diet effect on the structural properties of the erythrocyte cell membrane of hypertensive patients: the Prevencion con Dieta Mediterranea Study.

A currently ongoing randomized trial has revealed that the Mediterranean diet, rich in virgin olive oil or nuts, reduces systolic blood pressure in high-risk cardiovascular patients. Here, we present a structural substudy to assess the effect of a Mediterranean-style diet supplemented with nuts or virgin olive oil on erythrocyte membrane properties in 36 hypertensive participants after 1 year of intervention. Erythrocyte membrane lipid composition, structural properties of reconstituted erythrocyte membranes, and serum concentrations of inflammatory markers are reported. After the intervention, the membrane cholesterol content decreased, whereas that of phospholipids increased in all of the dietary groups; the diminishing cholesterol:phospholipid ratio could be associated with an increase in the membrane fluidity. Moreover, reconstituted membranes from the nuts and virgin olive oil groups showed a higher propensity to form a nonlamellar inverted hexagonal phase structure that was related to an increase in phosphatidylethanolamine lipid class. These data suggest that the Mediterranean-style diet affects the lipid metabolism that is altered in hypertensive patients, influencing the structural membrane properties. The erythrocyte membrane modulation described provides insight in the structural bases underlying the beneficial effect of a Mediterranean-style diet in hypertensive subjects.

Alternative treatment paradigm for thalassemia using iron chelators.

OBJECTIVE: beta-thalassemia major, or Cooley's anemia, is a red blood cell disorder requiring lifelong blood transfusions for survival. Erythrocytes accumulate toxic iron at their membranes, triggering an oxidative cascade that leads to their premature destruction in high numbers. We hypothesized that removing this proximate iron compartment as a primary treatment, using standard and alternative orally active iron chelators, could prevent hastened red cell removal and, clinically, perhaps alleviate the need for transfusion. MATERIALS AND METHODS: Iron chelators of the pyridoxal isonicotinoyl hydrazone family (pyridoxal isonicotinoyl hydrazone and its analog pyridoxal ortho-chlorobenzoyl hydrazone) were evaluated in addition to the present mainstay, desferrioxamine and deferiprone, in vitro and in vivo. RESULTS: Treatment of human beta-thalassemic erythrocytes with chelators resulted in significant depletion of membrane-associated iron and reduction of oxidative stress, as evaluated by methemoglobin levels. When administered to beta-thalassemic mice, iron chelators mobilized erythrocyte membrane iron, reduced cellular oxidation, and prolonged erythrocyte half-life. The treated thalassemic mice also showed improved hematological abnormalities. Remarkably, a beneficial effect as early as the erythroid precursor stage was manifested by normalized proportions of mature vs immature reticulocytes. All four compounds were also found to mitigate iron accumulation in target organs, a critical determinant for patient survival. In this respect, pyridoxal ortho-chlorobenzoyl hydrazone displayed higher activity relative to other chelators tested, further diminishing iron in liver and spleen by up to approximately fivefold and twofold, respectively. CONCLUSION: Our study demonstrates the ability of iron chelators to improve several of the fundamental pathological disturbances of thalassemia, and reveals their potential for clinical use in diminishing requirement for transfusion when administered early in disease development.

Haemolytic anaemia in a patient with anorexia nervosa.

We report on a 17-year-old female patient with severe anorexia nervosa (AN) (body mass index of 9.8 kg/m(2)) who developed hypophosphataemia (serum phosphate 0.4 nmol/l) and subsequent haemolytic anaemia during oral refeeding. Hypophosphataemia due to an increased phosphate uptake may lead to a reduction of erythrocyte adenosine triphosphate. This mechanism is important for the differential diagnosis of haemolytic anaemia in patients with AN. To prevent this complication, phosphate supplementation should be considered in the refeeding of severely malnourished patients.

Biological studies of Bolax gummifera, a plant of the Falkland Islands used as a treatment of wounds.

Aqueous and dichloromethane extracts of Bolax gummifera (Lam.) Sprengel (Apiaceae), a plant of the Falkland Islands used as a treatment of wounds, were studied in order to support the ethnopharmacological information related to the medicinal use of this plant. The antimicrobial, antioxidant and red blood cells membrane stabilizing activities were analyzed. The antimicrobial bioassay was carried out using the test turbidity method (OD 620 nm), the aqueous extract showing an 82% inhibition of Staphylococcus aureus but no activity against Pseudomonas aeruginosa. The dichloromethane extract inhibited both microorganisms: S. aureus in 94% and P. aeruginosa in 32%. No antioxidant activity could be observed using hydroperoxide-initiated chemiluminescence in rat liver homogenates. Investigations into the membrane stabilizing activity of the extracts were carried out using human red blood cells subjected to hypotonic- and heat-induced lyses. The aqueous extract showed an important stabilizing activity of the red blood cell membrane.