Preparation of liposomal hydrogel containing Calendula and application as a wound dressing.

Burn wound is one of the major medical and Hydrogels are one of the best wound dressings for burns. Herein, chitosan/Aloe vera hydrogel was prepared and cross-linked by genipin. The nano-liposomes of soy lecithin as a phospholipid containing calendula were added to the hydrogel. The surface morphology and functional groups were evaluated by SEM and FTIR methods, respectively. The average hydrodynamic diameter was calculated by the dynamic light scattering. Also, the nanoliposomes hydrogel containing calendula has a suitable swelling and vapor permeability. The encapsulation rate of calendula was 83 % which indicates a high load of calendula. In vivo release study of hydrogel containing calendula was achieved by the French diffusion cell. Finally, the cytotoxicity (MTT) test, the proliferation and viability of fibroblast cells (L929) were investigated and the results show no cytotoxicity of the hydrogel. for in vitro study, the passage of calendula-containing liposomes through the skin was investigated. Rat abdominal skin was used as a natural membrane. France diffusion cell was used as a two-compartment model to measure the amount of passage. The skin absorption of the calendula begins with a gentle slope and in 24 h approximately 90% of skin absorption has taken place.

Preparation, purification, and characterization of low-molecular-weight hyaluronic acid.

OBJECTIVE: The use and commercial value of hyaluronic acid (HA) as an important element in the pharmaceutical, biomedical, and cosmetics industry is because of its purity. Four recombinant strains of Corynebacterium glutamicum containing different genes were used to produce HA. RESULTS: The production parameters were measured and strain 183.2, with the highest amount of HA (2.15 mg/ml), was selected for further experiments. HA was precipitated by different ratios of ethanol-isopropanol at 4 °C and - 20 °C. Active charcoal (1%) was added to the solvent precipitation mixture at pH 5 and 10. Finally, to achieve more purity and separation, gel filtration chromatography was used. The best result was obtained using an ethanol-isopropanol ratio of 1:1 of at - 20 °C, followed by active charcoal treatment at the acidic pH, and three fractions of the chromatography with molecular weights of 27, 27-110, and < 27 KDa were more analyzed with electrophoresis and FTIR. CONCLUSIONS: The present study described a simple, economical, and reproducible method resulting in a high yield for low-MW HA from C. glutamicum.

The effect of lactobacillus cell size on its probiotic characteristics.

Screening for probiotic characteristics is usually associated with a series of assays and a large number of isolates to be tested, which can be sometimes costly and frustrating. For this reason, finding some indicators to predict the probiotic potential would be of great significance. In this study, 10 Lactobacillus strains including L. sakei, L. reuteri, L. delbrueckii subsp. lactis, L. delbrueckii subsp. delbrueckii, L. plantarum, L. acidophilus, L. rhamnosus, L. paracasei, L. salivarius, and L. gasseri were characterized by cell morphology and growth properties. The strains were then examined in terms of some probiotic characteristics including resistance to acid and bile conditions, ability to adhesion to intestinal epithelial cells, antioxidant activity, aggregation characteristics, antibacterial activity, hemolytic activity, and resistance to different antibiotics. Correlations between different quantitative features were analyzed using Pearson's coefficient (r). Results of this study provided first-time evidence for the effects of cell length on probiotic features. Based on statistical analysis, long Lactobacillus strains had often higher antioxidant and aggregation activities. Moreover, these long strains were usually more sensitive to acid and bile conditions and resulted in a lower CFU yield compared to short strains. By conducting morphological tests at the first step of screening, some strains would gain higher priority because of predicting a high performance in some of the desired characteristics. Therefore, the cost and time required for the subsequent tests would be significantly reduced.