Beta-cyclodextrin tetradecasulfate, a novel cyclic oligosaccharide, inhibits thrombus and neointimal formation after coronary vascular injury

The antiangiogenic properties of sulfated β-cyclodextrins in anticancer formulations incorporating 5-fluorouracil

Sulfated β-cyclodextrins (S-β-CDs) are useful excipients for improving the solubility of drugs. One such formulation incorporating 5-fluorouracil (5-FU), termed FD(S), showed improved efficacy over 5-FU alone in orthotopic carcinoma xenograft models. S-β-CDs have heparin-like anticoagulant properties, which may have contributed toward the improved antitumor effect of FD(S). S-β-CDs have also been reported to modify a number of processes involved in angiogenesis. Although the anticoagulant nature of S-β-CDs was established, the antiangiogenic properties of S-β-CDs within FD(S) were unknown. The effect of S-β-CD and FD(S) on the proliferation and migration of endothelial cells in live-cell kinetic assays, and the reorganization of human umbilical vein endothelial cells into tubule structures in vitro was assessed. The effects of S-β-CD on angiogenesis in vitro were validated ex vivo using the rat aorta ring assay and the chick embryo chorioallantoic membrane assay. S-β-CD does not alter proliferative endothelial cell sensitivity to 5-FU cytotoxicity. S-β-CD alone and within FD(S) significantly inhibited angiogenesis by impeding endothelial cell migration, resulting in the inhibition of tubule formation and hence new vasculature. In addition to the cytotoxic action of the drug 5-FU, therapeutic inhibition of angiogenesis by S-β-CDs within FD(S) could potentially limit local invasion and metastases. This has important implications for the exploitation of S-β-CDs for drug formulation improvements or for drug delivery of anticancer biologics.

Hydroxypropyl-β-cyclodextrin impacts renal and systemic hemodynamics in the anesthetized dog

Hydroxypropyl-β-cyclodextrin (HPβCD) is a complexation agent used to enhance drug solubilization and formulation stability. Although its toxicity is well characterized, its cardiovascular effects are less known. To investigate them, HPβCD was infused intravenously over 10 min in anesthetized dogs (10-40% (w/v, i.e. 200-800 mg/kg) in non-denervated animals and at 40% in denervated animals). HPβCD increased renal arteriolar resistance and decreased renal blood flow at all doses, almost immediately after infusion start, more drastically in females. A less pronounced increase in total peripheral resistance occurred in females only due to sex difference in sympathetic tone. Pulmonary hemodynamic parameters remained unaffected, suggesting that the renal effect was rather selective. As a consequence of the increased systemic blood pressure, heart rate decreased in normal animals without direct effect on cardiac conductance. This effect was abolished in denervated animals. This suggests that autonomous nervous feedback loops are functional in normal animals and that HPβCD has no direct chronotropic effect. In conclusion, systemic and renal hemodynamic changes should be considered as potential background effects at 200-400 mg/kg. At higher doses (800 mg/kg), changes are more pronounced and could mask/exacerbate hemodynamic response of drug candidate; such doses should be avoided in nonclinical safety studies.

Optimized alkylated cyclodextrin polysulphates with reduced risks on thromboembolic accidents improve osteoarthritic chondrocyte metabolism

OBJECTIVES

To compare the ability of different cyclodextrin polysulphate (CDPS) derivatives to affect human articular cartilage cell metabolism in vitro.

METHODS

OA chondrocytes were cultured in alginate and exposed to 5 µg/ml of 2,3,6-tri-O-methyl-β-cyclodextrin (ME-CD), 2,3-di-O-methyl-6-sulphate-β-cyclodextrin (ME-CD-6-S), 2,6-di-O-methyl-3-sulphate-β-cyclodextrin (ME-CD-3-S), (2-carboxyethyl)-β-CDPS (CE-CDPS), (2-hydroxypropyl)-β-CDPS (HP-CDPS), 6-monoamino-6-monodeoxy-β-CDPS (MA-CDPS) or β-CDPS for 5 days. Effects on IL-1-driven chondrocyte extracellular matrix (ECM) metabolism were assayed by analysis of the accumulation of aggrecan in the interterritorial matrix, IL-6 secretion and qPCR. MA-CDPS, HP-CDPS, CE-CDPS and CDPS were analysed for their in vitro effect on coagulation and their ability to activate platelets in an in vitro assay to detect possible cross-reactivity with heparin-induced thrombocytopenia (HIT) antibodies.

RESULTS

The monosulphated cyclodextrins ME-CD-6-S and -3-S failed to affect aggrecan synthesis and IL-6 secretion by the OA chondrocytes. Polysulphated cyclodextrins MA-CDPS, HP-CDPS, CE-CDPS and CDPS at 5 µg/ml concentrations, on the other hand, significantly induced aggrecan production and repressed IL-6 release by the chondrocytes in culture. aPTT and PT for all derivatives were lengthened for polysaccharide concentrations >50 µg/ml. Five micrograms per millilitre of β-CDPS concentrations that significantly modulated ECM ground substance production in vitro did not affect aPTT or PT. Furthermore, CE-CDPS, in contrast to MA-CDPS, HP-CDPS and CDPS, did not significantly activate platelets, suggesting a minimal potential to induce HIT thromboembolic accidents in vivo.

CONCLUSIONS

CE-CDPS is a new, structurally adjusted, sulphated β-cyclodextrin derivative with preserved chondroprotective capacity and a promising safety profile.

Separate and combined effects of local and continuous intravenous administration of beta-cyclodextrin tetradecasulfate on intimal hyperplasia after angioplasty in porcine coronary arteries

BACKGROUND

Beta-Cyclodextrin tetradecasulfate binds fibroblast growth factors and possesses anticoagulant properties. This study was designed to assess the separate and combined effects of local intramural delivery and intravenous administration of beta-cyclodextrin tetrade-casulfate on neointimal formation and arterial damage following angioplasty.

METHODS AND RESULTS

Fifty-two pigs randomized into four groups underwent coronary artery angioplasty: 1) control, 2) continuous intravenous infusion of 100 mg/kg/d of beta-cyclodextrin tetradecasulfate, 3) intramural delivery of 1250 mg beta-cyclodextrin tetradecasulfate, 4) intramural delivery of 1250 mg beta-cyclodextrin tetradecasulfate followed by continuous intravenous infusion of 100 mg/kg/d. Fourteen days after injury, morphometric analysis revealed that arteries randomized to the intravenous beta-cyclodextrin tetradecasulfate groups had a decreased normalized neointima area: control, 3.03 +/- 0.75 mm(2); intravenous, 1.67 +/- 0.73 mm(2) (40% decrease; P < 10(-7)); intravenous plus local, 1.95 +/- 0.76 mm(2) (30% decrease; P < 10(-5)). There was no difference in neointimal response following local beta-cyclodextrin tetradecasulfate delivery only (2.82 +/- 1.14 mm(2)). Coronary arterial damage, defined as aneurysm, dissection, adventitial rupture, and retromedial hematoma was similar in all groups (12% in control and local groups, 10% in the intravenous group, 14% in the intravenous plus local; NS). Bleeding complications were more frequent in the intravenous and intravenous plus local groups compared to the local and control groups (23%vs 7.6% and 0%, respectively; P < 0.05).

CONCLUSIONS

Continuous intravenous administration of beta-cyclodextrin tetradecasulfate substantially reduced intimal hyperplasia, while intramural delivery had no effect, indicating that a single bolus of beta-cyclodextrin tetradecasulfate did not reduce intimal hyperplasia. There was no additive effect of local intramural delivery of beta-cyclodextrin tetradecasulfate. However, local delivery of beta-cyclodextrin tetradecasulfate induced less bleeding complications and did not lead to additional arterial injury, indicating that local delivery of an anticoagulant does not cause additional arterial injury.