Oleic acid derivative of polyethylenimine-functionalized proliposomes for enhancing oral bioavailability of extract of Ginkgo biloba

Identification and direct determination of fatty acids profile in oleic acid by HPLC-CAD and MS-IT-TOF

Oleic acid is a pharmaceutical excipient and has been widely used in many dosage forms. It remains unclear in terms of the fatty acids (FAs) profile. In this study, a sensitive and direct method based on high-performance liquid chromatography coupled with charged aerosol detector (HPLC-CAD) was developed to study the compositions of oleic acid. The chromatographic conditions were optimized to achieve good separation and high sensitivity. The components of oleic acid were identified by ion trap/time of flight mass spectrometry (MS-IT-TOF). Twenty-seven FAs were identified based on the exact mass-to-charge ratio and fragments, among which 13 FAs were confirmed with the reference standards. Nine FAs in the oleic acid samples including oleic acid, linolenic acid, myristic acid, palmitoleic acid, linoleic acid, palmitic acid, stearic acid, arachidic acid and behenic acid were simultaneously determined by the developed HPLC-CAD, which showed good linearity with r²>0.999. The limit of detection (LOD) and limit of quantification (LOQ) of 9 FAs were 0.006-0.1 μg mL^-1 and 0.032-0.22 μg mL^-1, respectively. The components with concentration level not less than 0.03 % (referring to the sample concentration of 1.0 mg mL^-1) can be quantified. The mean recovery values of 9 FAs ranged from 96.5%-103.6% at three concentration levels of 80 %, 100 % and 120 %. The repeatability and intermediate precision were less than 5.0 % for oleic acid and components with concentration levels more than 0.05 %. In contrast to the conventional pre-column derivatization gas chromatography (GC), HPLC-CAD could unbiasedly and directly detect more components, especially the FAs with long carbon chains. Overall, the developed novel HPLC-CAD method can ameliorate the deficiency of the indirect GC method recorded in current pharmacopeias, thus having great potential for the comprehensive understanding and quality control of oleic acid.

Delivery of antisense oligonucleotide using polyethylenimine-based lipid nanoparticle modified with cell penetrating peptide

Efficient and stable delivery system of antisense oligonucleotide (ASO) is important and urgently needed. Here, an ASO delivery system, Lp-PPRP, which contains a cationic polymer based on PEI (branched, 25 kDa), named PEI-PC and a palmitic acid modified R8 (R8-PA) was prepared to deliver a kind of ASO, LOR-2501. The characteristics of the nanoparticles and the cellular uptake of LOR-2501 in HeLa cells and A549 cells were studied. Lp-PPRP showed suitable particle size and zeta potential to combine with LOR-2501; the particle size and zeta potential of Lp-PPRP/LOR were 276.87 ± 5.63 nm and 18.03 ± 0.25 mV. In vitro experiments suggested that Lp-PPRP had lower cytotoxic and higher transfection efficiency for delivering LOR-2501 compared with PEI. The addition of PEI-PC and R8-PA contributed to enhance the transfection efficiency of the nanoparticles. In HeLa cells and A549 cells, Lp-PPRP could transport LOR-2501 and down-regulate the level of R1 protein efficiently, and the R1 down regulations were 64.56% and 66.34%, respectively. Results suggested potential utility of Lp-PPRP in the development of ASO in tumor therapy.

Proliposomes for oral delivery of total biflavonoids extract from Selaginella doederleinii: formulation development, optimization, and in vitro-in vivo characterization

Purpose

Amentoflavone, robustaflavone, 2'',3''-dihydro-3',3'''-biapigenin, 3',3'''-binaringenin and delicaflavone are five major active ingredients in the total biflavonoids extract from Selaginella doederleinii (TBESD) with favorable anticancer properties. However, the natural-derived potent antitumor agent of TBESD is undesirable due to its poor solubility. The present study was to develop and optimize a proliposomal formulation of TBESD (P-TBESD) to improve its solubility, oral bioavailability and efficacy.

Materials and methods

P-TBESD containing a bile salt, a protective hydrophilic isomalto-oligosaccharides (IMOs) coating, were successfully prepared by thin film dispersion-sonication method. The physicochemical and pharmacokinetic properties of P-TBESD were characterized, and the antitumor effect was evaluated using the HT-29 xenograft-bearing mice models in rats.

Results

Compared with TBESD, the relative bioavailability of amentoflavone, robustaflavone, 2'',3''-dihydro-3',3'''-biapigenin, 3',3'''-binaringenin and delicaflavone from P-TBESD were 669%, 523%, 761%, 955% and 191%, respectively. The results of pharmacodynamics demonstrated that both TBESD and P-TBESD groups afforded antitumor effect without systemic toxicity, and the antitumor effect of P-TBESD was significantly superior to that of raw TBESD, based on the tumor growth inhibition and histopathological examination.

Conclusion

Hence, IMOs-modified proliposomes have promising potential for TBESD solving the problem of its poor solubility and oral bioavailability, which can serve as a practical oral preparation for TBESD in the future cancer therapy.

Enhanced gene transfection efficiency by low-dose 25 kDa polyethylenimine by the assistance of 1.8 kDa polyethylenimine

Gene therapy is a promising strategy for treatments of various diseases. Efficient and safe introduction of therapeutic genes into targeted cells is essential to realize functions of the genes. High-molecular-weight polyethylenimines (HMW PEIs) including 25 kDa branched PEI and 22 kDa linear PEI are widely used for in vitro gene transfection. However, high-gene transfection efficiency is usually accompanied with high cytotoxicity, which hampers their further clinical study. On the contrary, low-molecular-weight polyethylenimines (LMW PEIs) such as 1.8 kDa PEI and 800 Da PEI show good biocompatibility but their applications are limited by the poor DNA condensation capability. In this study, we find that 1.8 kDa PEI, but not 800 Da PEI combined with low-dose 25 kDa PEI could significantly promote gene transfection with low cytotoxicity. Plasmids encoding enhanced green fluorescence protein (EGFP) were delivered by the combined PEI and gene transfection efficiency was evaluated by microscopic observation and flow cytometry. Parameters including concentrations of 25 kDa PEI and 1.8 kDa PEI and preparation ways were further optimized. This study presents an efficient and safe combined PEI-based non-viral gene delivery strategy with potential for in vivo applications.