Ligand-based targeting of the receptors that are overexpressed explicitly on cancer cells represents an effective drug delivery approach to enhance the chemotherapeutic efficacy. Proprotein convertase subtilisin/kexin type 9 (PCSK9) which is a serine protease enzyme primarily produced by the liver cells, can potentially be used as a targeting ligand. PCSK9 binds to the LDL-r on hepatocytes\' surface, leading to endocytosis and endosomal degradation. High LDL-r expression, which is believed to meet the higher demand of the cholesterol and phospholipids to build proliferating cancer cell membrane, ensures selective uptake of the PCSK9 conjugated liposomes. In the present work, the PCSK9 conjugated liposomal system was developed to deliver paclitaxel (PTX) to cancer cells. The protein was conjugated by EDC and NHS in a two-step coupling reaction to the liposomes containing COOH-PEG2000-COOH lipid. Conjugation was confirmed by NMR, and liposomes were further characterized by SEM and zeta sizer. PCSK9-conjugated liposomes showed high encapsulation efficiency of 69.1% with a diameter of 90.0 ± 4.9 nm. Long-term stability (30 days) study (Zeta potential: -9.88) confirmed excellent constancy and significant drug retention (58.2%). Invitro cytotoxicity and targeting efficiency was explored using MTS assay in human embryonic kidney cells (HEK293), liver hepatocellular cells (HEPG2), and a human colon cancer cell line (HCT116) for 24 h. PCSK9 conjugated liposomes exhibited significantly higher growth inhibition than the unconjugated (control) liposomes in HCT116 cell line (p < 0.001). The novel PCSK9 conjugated liposomes presented potent and precise in vitro anticancer activity and, therefore, are suggested for the first time as a promising targeted delivery system for cancer treatment.

Small rodents, especially mice and rats, have been widely used in atherosclerosis studies even though humans exhibit completely different lipoprotein metabolism and atherosclerotic characteristics. Until recently, various rodent models of human familial hypercholesterolemia (FH) have been created, including mice, rats, and golden Syrian hamsters. Although hamsters reportedly possess metabolic features similar to humans, there is no systematic characterization of the properties of circulating lipids and atherosclerotic lesions in these rodent models. We used three FH animal species (mice, rats, and hamsters) with low-density lipoprotein receptor (Ldlr) deficiency to fully assess lipoprotein metabolism and atherosclerotic characteristics. Compared to chow diet-fed mice and rats, Ldlr knockout (KO) hamsters showed increased cholesterols in LDL fractions similar to human FH patients. Upon 12-week high-cholesterol/high-fat diet feeding, both heterozygous and homozygous Ldlr KO hamsters displayed hyperlipidemic phenotypes, whereas only homozygous Ldlr KO mice and rats showed only moderate increases in plasma lipid levels. Moreover, rats were resistant to diet-induced atherosclerosis compared to mice, and hamsters showed more atherosclerotic lesions in the aortas and coronary arteries. Further morphological study revealed that only hamsters developed atherosclerosis in the abdominal segments, which is highly similar to FH patients. This unique animal model will provide insight into the translational study of human atherosclerosis and could be useful for developing novel treatments for FH patients.

To evaluate the effect of alirocumab on frequency of standard apheresis treatments [weekly or every 2 weeks (Q2W)] in heterozygous familial hypercholesterolaemia (HeFH).
ODYSSEY ESCAPE (NCT02326220) was a double-blind study in 62 HeFH patients undergoing regular weekly or Q2W lipoprotein apheresis. Patients were randomly assigned (2:1, respectively) to receive alirocumab 150 mg (n = 41) or placebo (n = 21) Q2W subcutaneously for 18 weeks. From day 1 to week 6, apheresis rate was fixed according to the patient\'s established schedule; from weeks 7 to 18, apheresis rate was adjusted based on the patient\'s low-density lipoprotein cholesterol (LDL-C) response in a blinded fashion. Apheresis was not performed when the LDL-C value was ≥30% lower than the baseline (pre-apheresis) value. The primary efficacy endpoint was the rate of apheresis treatments over 12 weeks (weeks 7-18), standardized to number of planned treatments. In the alirocumab group the least square (LS) mean ± SE (95% confidence interval [CI]) per cent change in pre-apheresis LDL-C from baseline at week 6 was -53.7 ± 2.3 (-58.2 to - 49.2) compared with 1.6 ± 3.1 (-4.7 to 7.9) in the placebo group. The primary efficacy endpoint showed statistically significant benefit in favour of alirocumab (Hodges-Lehmann median estimate of treatment difference: 0.75; 95% CI 0.67-0.83; P < 0.0001). Therefore, alirocumab-treated patients had a 0.75 (75%) additional reduction in the standardized rate of apheresis treatments vs. placebo-treated patients. During this period, 63.4% of patients on alirocumab avoided all and 92.7% avoided at least half of the apheresis treatments. Adverse event rates were similar (75.6% of patients on alirocumab vs. 76.2% on placebo).
Lipoprotein apheresis was discontinued in 63.4% of patients on alirocumab who were previously undergoing regular apheresis, and the rate was at least halved in 92.7% of patients. Alirocumab was generally safe and well tolerated.

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