Rapid Cu(II)-Directed Self Assembly of Esterified Tea Polyphenol Oligomers to Controlled Release Nanoflower Carrier

In this study, novel tea polyphenolic-copper hybrid nanoflowers were assembled with tea polyphenol palmitate oligomers generated simply through air oxidation. It was revealed that the growth of tea polyphenolic-based hybrid nanoflowers was notably faster than protein-based ones, presumably owing to rigid polyphenolic molecular architecture and the resultant different growth mechanism. The structures and composition investigation by FT-IR, X-ray, and SEM-EDS unveiled that the whole framework of the nanoflowers was composed of complexes of tea polyphenolic oligomers and copper phosphate crystals. The tea polyphenolic hybrid nanoflowers demonstrated high loading capacity of curcumin due to flower-like porous structure and hydrophobic pockets furnished by lipophilic side chains. The nanoflowers exhibited remarkable protection capacity for carried curcumin from UV irradiation and thermal treatment. Controlled release of the nanoflowers could be readily achieved by adjustment of pH condition. Owing to high assembly efficiency, biocompatibility, and natural abundance, tea polyphenols are intriguing organic components to generate nanoflowers.

Grape seed extract-soluplus dispersion and its antioxidant activity

OBJECTIVE

The main objective of this work was to formulate a nanodispersion containing grape seed extract and analyzed its release profile, antioxidant potential of the prepared formulations.

METHODS

The grape seed extract (GSE) containing proanthocyanidins (PC's) has been dispersed in polymer matrix soluplus (SOLU) by the freeze-drying method. The morphological analysis was carried out using atomic force microscopy (AFM), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The in-vitro release of the nanodispersion formulations was evaluated by simulated intestinal fluid (SIF). The antioxidant activity of GSE and the formulation were evaluated by employing various in-vitro assays such as 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2, 2-diphenyl-1- picrylhydrazyl (DPPH), Ferric reducing antioxidant power (FRAP) and peroxidation inhibiting activity.

RESULTS

The formulation FIII (1:5) resulted in a stable formulation with a higher loading efficiency of 95.36%, a particle size of 69.90 nm, a polydispersity index of 0.154 and a zeta potential value of -82.10 mV. The antioxidant efficiency of GSE-SOLU evaluated by DPPH was found to be 96.7%. The ABTS and FRAP model exhibited a dose-dependent scavenging activity. Linoleic model of FIII formulation and GSE exhibited a 66.14 and 86.58% inhibition respectively at 200 µg/l.

CONCLUSIONS

The main reason for excellent scavenging activity of the formulations can be attributed to the presence of monomeric, dimeric, oligomeric procyanidins and the phenolic group. The present work denotes that GSE constitutes a good source of PC's and will be useful in the prevention and treatment of free radical related diseases.

Binary and Tertiary Complex Based on Short-Chain Glucan and Proanthocyanidins for Oral Insulin Delivery

The present study was performed to investigate binary and tertiary nanocomposites between short-chain glucan (SCG) and proanthocyanidins (PAC) for the oral delivery of insulin. There was a large decrease in fluorescence intensity of insulin in the presence of SCG or the combination of SCG with PAC. Fourier transform infrared spectroscopy revealed that the binary and tertiary nanocomposites were synthesized due to the hydrogen bonding and hydrophobic interactions. The insulin entrapped in the nanocomposites was in an amorphous state confirmed by X-ray diffraction. The cell culture demonstrated that both the nanocomposites showed no detectable cytotoxicity with relative cell viability all above 85%. The pharmacological bioavailability after oral administration of insulin-SCG-PAC at a dose of 100 IU/kg was found to be 6.98 ± 1.20% in diabetic rats without any sharp fluctuations in 8 h.