In vitro and in vivo evaluation of folate receptor-targeting amphiphilic copolymer-modified liposomes loaded with docetaxel

Xiang Li1, Xin Tian2, Jing Zhang3, Xu Zhao1, Xiaohui Chen1, Youhong Jiang2, Dongkai Wang1, Weisan Pan11Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang; 2The Second Laboratory of Cancer Research Institution, The First Hospital of China Medical University, Shenyang; 3Key Laboratory of Modern Preparation of TCM, Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang, ChinaBackground: The purpose of this study was to develop folate-poly (PEG-cyanoacrylate-co-cholesteryl cyanoacrylate) (FA-PEG-PCHL)-modified freeze-dried liposomes for targeted chemotherapy using docetaxel as a model drug.Methods: FA-PEG-PCHL was synthesized and its cytotoxicity was evaluated by CCK-8 assay in L929. Docetaxel-loaded liposomes modified by FA-PEG-PCHL were prepared by an organic solvent injection method and lyophilized to obtain freeze-dried FA-PEG-PCHL-docetaxel liposomes (FA-PDCT-L). Two carcinoma cell lines (MCF-7 and A-549 cells) were cultured with docetaxel solution, conventional docetaxel-loaded liposomes, or FA-PDCT-L, and the cytotoxicity and apoptosis was evaluated for each preparation. The uptake of the docetaxel preparations into MCF-7 cells was studied by confocal laser scanning microscopy. Liquid chromatography-mass spectrometry was used to study the pharmacokinetics and tissue distribution characteristics of the preparations.Results: The existence of an enlarged fixed aqueous layer on the surface of the liposomes was affirmed by zeta potential analysis. The entrapment efficiency and particle size distribution were almost the same as those of docetaxel-loaded liposomes. The drug release profile showed that the release rate was faster at higher molecular weight of the polymer. Compared with docetaxel solution and docetaxel-loaded liposomes, FA-PDCT-L demonstrated the strongest cytotoxicity against two carcinoma cell lines, the greatest intracellular uptake especially in the nucleus, as well as the most powerful apoptotic efficacy. In pharmacokinetic studies, the area under the plasma concentration-time curve of FA-PDCT-L was increased 3.82 and 6.23 times in comparison with the values for the docetaxel-loaded liposomes and docetaxel solution, respectively. Meanwhile, a lower concentration of docetaxel was observed for FA-PDCT-L in the liver and spleen, and a significantly higher concentration of FA-PDCT-L in tumors suggested that the presence of FA-PEG-PCHL on the liposomes resulted in greater accumulation of the drug in tumor tissue.Conclusion: Liposomes modified by FA-PEG-PCHL could be one of the promising suspensions for the delivery of antitumor drugs in cancer.Keywords: folate-poly (PEG-cyanoacrylate-co-cholesteryl cyanoacrylate), docetaxel, freeze-dried liposomes, tumor targetin

Development and evaluation of orally disintegrating tablet containing mosapride resin complex

The purpose of this study was to prepare a mosapride citrate-resin (Amberlite® IRP 88) complex and orally fast-disintegrating tablets of the resin complex. The resinate complex of mosapride-Amberlite® IRP 88, weight ratio 2:1, was prepared in an ethanol-water solution. The effects of alcohol concentration, temperature, and pH of the solution on complex formation were evaluated. The complex physicochemical properties were characterized by differential scanning calorimetry, X-ray diffraction and scanning electron microscopy. Orally disintegrating tablets were prepared by direct compression and were optimized using the response surface method. Optimized orally fast-disintegrating tablets disintegrated within 18 s. The pH dependence of mosapride release from the tablet decreased drug dissolution in simulated saliva, whereas it promptly released in the pH 1.0 solution. The data reported herein clearly demonstrate that tablets containing the mosapride- Amberlite® IRP 88 complex for oral disintegration could be particularly useful for patients with swallowing difficulties

Suboptimal SARS-CoV-2-specific CD8+ T cell response associated with the prominent HLA-A*02:01 phenotype

An improved understanding of human T cell-mediated immunity in COVID-19 is important for optimizing therapeutic and vaccine strategies. Experience with influenza shows that infection primes CD8+ T cell memory to peptides presented by common HLA types like HLA-A2, which enhances recovery and diminishes clinical severity upon reinfection. Stimulating peripheral blood mononuclear cells from COVID-19 convalescent patients with overlapping peptides from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to the clonal expansion of SARS-CoV-2−specific CD8+ and CD4+ T cells in vitro, with CD4+ T cells being robust. We identified two HLA-A*02:01-restricted SARS-CoV-2-specfic CD8+ T cell epitopes, A2/S269–277 and A2/Orf1ab3183–3191. Using peptide−HLA tetramer enrichment, direct ex vivo assessment of A2/S269+CD8+ and A2/Orf1ab3183+CD8+ populations indicated that A2/S269+CD8+ T cells were detected at comparable frequencies (∼1.3 × 10−5) in acute and convalescent HLA-A*02:01+ patients. These frequencies were higher than those found in uninfected HLA-A*02:01+ donors (∼2.5 × 10−6), but low when compared to frequencies for influenza-specific (A2/M158) and Epstein–Barr virus (EBV)-specific (A2/BMLF1280) (∼1.38 × 10−4) populations. Phenotyping A2/S269+CD8+ T cells from COVID-19 convalescents ex vivo showed that A2/S269+CD8+ T cells were predominantly negative for CD38, HLA-DR, PD-1, and CD71 activation markers, although the majority of total CD8+ T cells expressed granzymes and/or perforin. Furthermore, the bias toward naïve, stem cell memory and central memory A2/S269+CD8+ T cells rather than effector memory populations suggests that SARS-CoV-2 infection may be compromising CD8+ T cell activation. Priming with appropriate vaccines may thus be beneficial for optimizing CD8+ T cell immunity in COVID-19

Preparation and Performance Analysis of Modified Sodium Acetate Trihydrate

In order to solve undercooling and phase separation of sodium acetate trihydrate (SAT), experimental screening method was used to select nucleating agents and thickeners that are suitable for SAT, and the optimal ratio was identified. Through screening experiments of nucleating agents, it is found that disodium hydrogen phosphate can be used as an effective nucleating agent for SAT. When the weight content of disodium hydrogen phosphate in SAT is 2%, the degree of undercooling was reduced to approximately 2 K. The addition of 1–1.5% (weight) of xanthan gum (XG) to SAT can effectively inhibit the phase separation. Since the properties of SAT changes after the modification, the corresponding comparison analysis was performed. The results showed that XG has a significant influence on the SAT performance of SAT. With the addition of 1.5 wt % of XG in pure SAT, the latent heat of fusion and solid/liquid volume expansion reduce by 5.2% and 5.4% respectively, and the thermal conductivity and solid/liquid density also decreases accordingly

The Effect of Hydroxylated Multi-Walled Carbon Nanotubes on the Properties of Peg-Cacl2 Form-Stable Phase Change Materials

Calcium ions can react with polyethylene glycol (PEG) to form a form-stable phase change material, but the low thermal conductivity hinders its practical application. In this paper, hydroxylated multi-walled carbon nanotubes (MWCNTs) with different mass are introduced into PEG1500·CaCl2 form-stable phase change material to prepare a new type of energy storage material. Carbon nanotubes increased the mean free path (MFP) of phonons and effectively reduced the interfacial thermal resistance between pure PEG and PEG1500·CaCl2 3D skeleton structure. Thermal conductivity was significant improved after increasing MWCNTs mass, while the latent heat decreases. At 1.5 wt%, composite material shows the highest phase change temperature of 42 °C, and its thermal conductivity is 291.30% higher than pure PEG1500·CaCl2. This article can provide some suggestions for the preparation and application of high thermal conductivity form-stable phase change materials

Chitosan-based liposomal thermogels for the controlled delivery of pingyangmycin: design, optimization and in vitro and in vivo studies

Pingyangmycin (PYM) has been applied clinically for many years to treat vascular malformations (VM) in China. The major limitation of PYM injections is quick diffusion from the injection site, which increases side effects, especially the possibility of pulmonary injury. In this paper, chitosan/glycerophosphate disodium (CS/GP) thermogels containing liposomes for sustained and localized PYM delivery were prepared and optimized by a three-level three-factorial Box–Behnken experimental design to evaluate the effects of different variables (the PYM concentration, CS amount and GP content), on the selected responses (cumulative percentage PYM released in 1 day, 9 days and the rate constant k). The results revealed that the optimized PYM liposomal thermogels had a controlled PYM release for 14 days in vitro, which confirmed the validity of optimization. In vitro morphological observation, cell cycle and apoptosis analysis showed an effective anti-proliferation action of PYM liposomal thermogels on human vascular endothelial cells (EA.hy926). In vivo pharmacokinetics research in rabbits displayed that compared with PYM liposomes and PYM thermogels, PYM liposomal thermogels had a better controlled delivery of PYM. Histological examination of rabbit ear veins showed that after local application with PYM lipsomal thermogels for 21 days, obvious vein thrombosis and inflammatory reaction could be observed. The above results indicated that PYM-loaded lipsomal CS/GP thermogels might have a good prospect for the treatment of VM

Developments in Methods for Measuring the Intestinal Absorption of Nanoparticle-Bound Drugs

With the rapid development of nanotechnology, novel drug delivery systems comprising orally administered nanoparticles (NPs) have been paid increasing attention in recent years. The bioavailability of orally administered drugs has significant influence on drug efficacy and therapeutic dosage, and it is therefore imperative that the intestinal absorption of oral NPs be investigated. This review examines the various literature on the oral absorption of polymeric NPs, and provides an overview of the intestinal absorption models that have been developed for the study of oral nanoparticles. Three major categories of models including a total of eight measurement methods are described in detail (in vitro: dialysis bag, rat gut sac, Ussing chamber, cell culture model; in situ: intestinal perfusion, intestinal loops, intestinal vascular cannulation; in vivo: the blood/urine drug concentration method), and the advantages and disadvantages of each method are contrasted and elucidated. In general, in vitro and in situ methods are relatively convenient but lack accuracy, while the in vivo method is troublesome but can provide a true reflection of drug absorption in vivo. This review summarizes the development of intestinal absorption experiments in recent years and provides a reference for the systematic study of the intestinal absorption of nanoparticle-bound drugs

Auricularia auricular polysaccharide-low molecular weight chitosan polyelectrolyte complex nanoparticles: Preparation and characterization

Novel polyelectrolyte complex nanoparticles (AAP/LCS NPs) were prepared in this study and these were produced by mixing negatively charged auricularia auricular polysaccharide (AAP) with positively charged low molecular weight chitosan (LCS) in an aqueous medium. The AAP was extracted and purified from auricularia auricular, and then characterized by micrOTOF-Q mass spectrometry, UV/Vis spectrophotometry, moisture analyzer and SEM. The yield, moisture, and total sugar content of the AAP were 4.5%, 6.2% and 90.12% (w/w), respectively. The AAP sample was water-soluble and exhibited white flocculence. The characteristics of AAP/LCS NPs, such as the particle size, zeta potential, morphology, FT-IR spectra, DSC were investigated. The results obtained revealed that the AAP/LCS NPs had a spherical shape with a diameter of 223 nm and a smooth surface, and the results of the FT-IR spectra and DSC investigations indicated that there was an electrostatic interaction between the two polyelectrolyte polymers. Bovine serum albumin (BSA, pI = 4.8) and bovine hemoglobin (BHb, pI = 6.8) were used as model drugs to investigate the loading and release features of the AAP/LCS NPs. The results obtained showed that the AAP/LCS NPs had a higher entrapment efficiency (92.6%) for BHb than for BSA (81.5%). The cumulative release of BSA and BHb from AAP/LCS NPs after 24 h in vitro was 95.4% and 91.9%, respectively. The in vitro release demonstrated that AAP/LCS NPs provided a sustained release matrix suitable for the delivery of protein drugs. These studies demonstrate that AAP/LCS NPs have a very promising potential as a delivery system for protein drugs