Elsevier

Biomaterials

Volume 33, Issue 17, June 2012, Pages 4424-4430
Biomaterials

Tumor vasculature targeting following co-delivery of heparin-taurocholate conjugate and suberoylanilide hydroxamic acid using cationic nanolipoplex

https://doi.org/10.1016/j.biomaterials.2012.02.066Get rights and content

Abstract

The chemical conjugate of low molecular weight heparin with taurocholate (LHT7) was previously designed to offer anticancer activity while minimizing the anticoagulant activity. In the present study, we found that the systemic administration of LHT7 in nanolipoplex could substantially enhance tumor vasculature targeting and anticancer effects. Moreover, we found that co-delivery of LHT7 with suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, in nanolipoplex could provide synergistic antitumor effect. LHT7/SAHA nanolipoplex was formulated by encapsulating SAHA inside cationic liposomes, followed by complexation of negatively charged LHT7 onto the cationic surfaces of SAHA-loaded liposomes (SAHA-L). LHT7/SAHA nanolipoplex was positively charged with a mean diameter of 117.6 nm, and stable in serum. The nanolipoplex form of LHT7 could alter its pharmacokinetics and biodistribution. Compared to the free form of LHT7, LHT7 in the nanolipoplex showed 1.9-fold higher mean residence time, and higher tumor vasculature accumulation after its intravenous administration. LHT7/SAHA nanolipoplex showed highest antitumor efficacy in SCC-bearing mice, compared to LHT7, SAHA-L and sequential co-administration of LHT7 and SAHA-L. Consistent with the enhanced antitumor effect, the reduction of abnormal vessels in the tumor site was also the highest in the LHT7/SAHA nanolipoplex-treated group. These results suggested the potential of LHT7/SAHA nanolipoplex for enhanced tumor vasculature targeting, and the importance of nanolipoplex-mediated co-delivery with a histone deacetylase inhibitor for maximal anticancer effect.

Introduction

Heparin, widely used as an anticoagulant drug, has been studied as an anticancer drug [1] for its inhibition effect on cancer cell proliferation, adhesion, angiogenesis, migration and invasion [2]. However, heparin anticoagulant activity causes adverse effects such as bleeding, which limits its expanded applications. In the previous study, Lee et al. reported a low molecular weight heparin (LMWH)-derived angiogenesis inhibitor with a low anticoagulant activity but with high antiangiogenic efficacy [3]. Moreover, the newly developed angiogenesis inhibitor, namely LMWH-taurocholate conjugate (LHT7), would be a promising agent owing to its wide range of inhibition effects on several angiogenic factors such as vascular endothelial growth factor, basic fibroblast growth factor, and platelet-derived endothelial cell growth factor [3]. Considering that the kinds of angiogenic factors that are released from the tumor tend to increase as tumor progresses, multi-targeting antiangiogenic drugs such as LHT7 would be preferred to inhibit tumoral angiogenesis [4], [5].

To increase the biodistribution of antiangiogenic drugs to tumor vasculature, various approaches have been tried to enhance targeting efficiency of anticancer drugs to tumor vasculature using nanoparticles such as nanospheres [6] and liposomes [7]. It has been well-recognized that the nanoparticulate drugs can be distributed more effectively to tumor vasculatures due to the enhanced permeability and retention (EPR) effect, which explains the leaky vascular nature of actively angiogenic tumor tissues [8]. Among various nanoparticles, cationic liposomes have been reported to provide tumor vasculature targeting property, probably due to the increased exposure of anionic phospholipids on the surfaces of tumor blood vessels [9], [10]. Once arrived at the tumor vascular region, the prolonged retention in tumor vasculature as nanoparticular forms might be beneficial. There exists a strong rationale to deliver angiogenesis inhibitor using nanoparticles as nanoparticular angiogenesis inhibitors can reduce new blood vessels formation following EPR effect-based tumor vasculature targeting [11].

In addition to the tumor vasculature targeting using nanoparticles, the combination therapy of angiogenesis inhibitors with other drugs would be one of the approaches to enhance the anticancer effects. Histone deacetylase inhibitors are one of thenew class anticancer drugs affecting cell cycles, apoptosis, and protein expressions [12]. Although histone deacetylase inhibitor monotherapy has been demonstrated to be effective in cancer therapy, most clinical trials have used combinations of histone deacetylase inhibitors with various anticancer chemotherapeutics simultaneously or sequentially [13]. Recently, combined treatment of a histone deacetylase inhibitor with an angiogenesis inhibitor was shown to increase the anticancer activity in rat hepatoma [14]. However, most combination studies have used histone deacetylase inhibitors with other drugs without using nanoparticles.

In this study, we hypothesized that the targeting delivery of LHT7 to tumor vasculature using cationic nanoliposomes may enhance the anti-angiogenic activity of LHT7, and that the co-delivery of LHT7 with histone deacetylase inhibitor using the multifunctional cationic nanolipoplex may further increase the therapeutic anticancer activity of anti-angiogenic drugs after tumor vasculature targeting. To evaluate this hypothesis, we formulated a multifunctional nanolipoplex carrying LHT7 together with a histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA). We utilized the negative charge of LHT7 and slightly soluble property of SAHA to complex LHT7 on the surface of cationic nanoliposomes and to entrap SAHA inside. After the co-delivery of LHT7 and SAHA in nanolipoplexes, the antiangiogenic effect, in vivo anticancer activity, and biodistribution of the compounds were evaluated.

Section snippets

Materials

LMWH (Fraxiparin®; average MW 4.5 kDa) was obtained from Nanjing King-Friend Biochemical Pharmaceutical Company Ltd. (Nanjing, China). Taurocholic acid sodium salt (TCA), N-hydroxysuccinimide (HOSu), N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC), dimethyl sulfoxide (DMSO), fluorescein isothiocyanate (FITC) and cholesterol were purchased from Sigma–Aldrich Chemical Co. (St. Louis, MO). Dioleyl-sn-glycero-3-phosphoethanolamine, 1,

Characterization of LHT7/SAHA nanolipoplex

LHT7 was complexed to the surfaces of cationic SAHA-L by charge–charge interaction. The cationic charges of liposome were conferred using an anionic amino acid-derived cationic N′, N″-dioleylglutamide. Polyethylene glycol moieties exist on the surfaces of N′, N″-dioleylglutamide-based cationic liposome by addition of PEG–DSPE at 1.0 m percentage during liposome preparation. To find out the optimal complexation ratio between LHT7 and SAHA-L, gel retardation pattern was evaluated at various

Discussion

In this study, we demonstrated that the delivery of LHT7 in the nanolipoplex formulation could prolong the retention of LHT7 as well as enhance its accumulation in the tumor site. Moreover, co-delivery of LHT7 and a histone deacetylase inhibitor, SAHA, in the nanolipoplex formulation could significantly improve the anticancer effect of LHT7.

For the formation of nanolipoplex with anionic LHT7, we used N′, N″-dioleylglutamide as a cationic lipid in liposome compostion. N′, N″-dioleylglutamide was

Conclusions

Our results indicate that the formulation of LHT7 in nanolipoplex could prolong the retention time and enhance tumor vasculature targeting. Moreover, the co-delivery of LHT7 with a histone deacetylase inhibitor SAHA in nanolipoplex provided the synergistic antitumor effects although the consequent co-treatment of LHT7 and SAHA-L did not reveal any synergistic activity. Furthermore, the systemic administration of LHT7 in nanolipoplex could decrease the numbers of abnormal blood vessels in tumor

Acknowledgments

This study was supported by a grant from the World Class University (WCU) program (grant no. R31-2008-000-10103) and the Converging Research Center Program (grant no. 2011K000809, 2011K000959) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology, and from Korean Health Technology R&D Project (Grant No. A092010), Ministry for Health, Welfare & Family Affairs, Republic of Korea.

References (24)

  • C.R. Patra et al.

    Targeted delivery of gemcitabine to pancreatic adenocarcinoma using cetuximab as a targeting agent

    Cancer Res

    (2008)
  • A.S. Abu Lila et al.

    Recent advances in tumor vasculature targeting using liposomal drug delivery systems

    Expert Opin Drug Deliv

    (2009)
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