Effect of Different Karyophilic Peptides on Physical Characteristics and In Vitro Transfection Efficiency of Chitosan-Plasmid Nanoparticles as Nonviral Gene Delivery Systems.

A strategy to increase the transfection efficiency of chitosan-based nanoparticles for gene therapy is by adding nuclear localization signals through karyophilic peptides. Here, the effect of the length and sequence of these peptides and their interaction with different plasmids on the physical characteristics and biological functionality of nanoparticles is reported. The karyophilic peptides (P1 or P2) were used to assemble nanoparticles by complex coacervation with pEGFP-N1, pQBI25 or pSelect-Zeo-HSV1-tk plasmids, and chitosan. Size, polydispersity index, zeta potential, and morphology, as well as in vitro nucleus internalization and transfection capability of nanoparticles were determined. The P2 nanoparticles resulted smaller compared to the ones without peptides or P1 for the three plasmids. In general, the addition of either P1 or P2 did not have a significant impact on the polydispersity index and the zeta potential. P1 and P2 nanoparticles were localized in the nucleus after 30 min of exposure to HeLa cells. Nevertheless, the presence of P2 in pEGFP-N1 and pQBI25 nanoparticles raised their capability to transfect and express the green fluorescent protein. Thus, karyophilic peptides are an efficient tool for the optimization of nonviral vectors for gene delivery; however, the sequence and length of peptides have an impact on characteristics and functionality of nanoparticles.

Anti-Diabetic Activity of Glycyrrhetinic Acid Derivatives FC-114 and FC-122: Scale-Up, In Silico, In Vitro, and In Vivo Studies.

Type 2 diabetes (T2D) is one of the most common diseases and the 8th leading cause of death worldwide. Individuals with T2D are at risk for several health complications that reduce their life expectancy and quality of life. Although several drugs for treating T2D are currently available, many of them have reported side effects ranging from mild to severe. In this work, we present the synthesis in a gram-scale as well as the in silico and in vitro activity of two semisynthetic glycyrrhetinic acid (GA) derivatives (namely FC-114 and FC-122) against Protein Tyrosine Phosphatase 1B (PTP1B) and α-glucosidase enzymes. Furthermore, the in vitro cytotoxicity assay on Human Foreskin fibroblast and the in vivo acute oral toxicity was also conducted. The anti-diabetic activity was determined in streptozotocin-induced diabetic rats after oral administration with FC-114 or FC-122. Results showed that both GA derivatives have potent PTP1B inhibitory activity being FC-122, a dual PTP1B/α-glucosidase inhibitor that could increase insulin sensitivity and reduce intestinal glucose absorption. Molecular docking, molecular dynamics, and enzymatic kinetics studies revealed the inhibition mechanism of FC-122 against α-glucosidase. Both GA derivatives were safe and showed better anti-diabetic activity in vivo than the reference drug acarbose. Moreover, FC-114 improves insulin levels while decreasing LDL and total cholesterol levels without decreasing HDL cholesterol.

Chitin/chitosan extraction from shrimp shell waste by a completely biotechnological process.

Two lactic bacteria were used in sequential co-cultures to demineralize (DM) and deproteinize (DP) shrimp shells (SS) to obtain chitin. During the first 24 h, Lactobacillus delbrueckii performed the DM in a minimal medium containing 100 g/L SS and 50 g/L glucose. Then, three different conditions were assayed to complete DM and perform the DP stage: 1) Bifidobacterium lactis was added with 35 g/L of glucose (Ld-G â†’ Bl-G); 2) only B. lactis was added (Ld-G â†’ Bl); and 3) a 35 g/L pulse of glucose was added, and at 48 h, B. lactis was inoculated (Ld-G â†’ G â†’ Bl). The highest DM (98.63 %) and DP (88 %) were obtained using a glucose pulse in the DM step and controlling the pH value above 6.0 in the DP step. Finally, a deacetylases cocktail produced by Aspergillus niger catalyzed the deacetylation of the resulting chitin. The chitosan samples had a deacetylation degree higher than 78 % and a solubility of 25 % in 1.0 N acetic acid. The deacetylation yield was 74 % after a mild chemical treatment, with a molecular weight of 71.31 KDa. This work reports an entirely biological process to get chitin and chitosan from SS with high yields.

Maize seed coatings and seedling sprayings with chitosan and hydrogen peroxide: their influence on some phenological and biochemical behaviors.

OBJECTIVE: To evaluate the effect of chitosan (CH) and hydrogen peroxide (H(2)O(2)) seed coatings and seedling sprinklings on two different maize varieties by measuring their phenology, the H(2)O(2) presence, the catalase (CAT) activity, and the protein quantity. METHODS: Seven groups of ten seeds for each maize variety were treated with CH (2% (20 g/L) and 0.2% (2 g/L)) or H(2)O(2) (8 mmol/L) by coating, sprinkling, or both. Germination and seedling growth were measured. One month after germination, the presence of H(2)O(2) in seedlings in the coated seed treatments was evaluated. Protein content and CAT activity were determined under all treatments. RESULTS: H(2)O(2) seed coating enhanced the germination rate and increased seedling and stem length in the quality protein maize (QPM) variety. Seedlings had a higher emergence velocity under this treatment in both varieties. CH and H(2)O(2) sprinklings did not have an effect on seedling phenology. Exogenous application of H(2)O(2) promoted an increase of endogenous H(2)O(2). CH and H(2)O(2) seedling sprinkling increased the protein content in both maize varieties, while there was no significant effect on the CAT activity of treated seeds and seedlings. CONCLUSIONS: CH and H(2)O(2) enhance some phenological and biochemical features of maize depending on their method of application.