Nanoparticles functionalized with Pep-1 as potential glioma targeting delivery system via interleukin 13 receptor α2-mediated endocytosis
Introduction
At present, glioblastoma multiforme (GBM) is the most frequent primary central nervous system tumor in human [1]. Because of its diffuse invasion of the surrounding normal brain tissue, it is impossible to eradicate the peripheral infiltrating part by surgery [2]. Therefore, chemotherapy seems necessary in the treatment of glioma. However, the currently available therapeutics by chemotherapy have less than optimal usefulness for GBM, mainly owing to delivery problems to tumor, including the low permeability of drug across blood tumor barrier (BTB) and poor glioma targeting of the chemotherapeutics [3], [4].
It was showed that if the local drug concentration was elevated by twofold, the efficacy to kill the brain tumor cells could be increased by tenfold [5]. Therefore, efficient delivery of drugs to glioma cells is crucial for effective chemotherapy of glioma. Many efforts have been made to enhance the penetration across the BTB [6], [7], [8], [9]. Nanoparticulate drug delivery systems have been attracted increasing attentions in recent years. The major advantages of nanoparticles include their sustained release property, high drug loading and the property of passive targeting by the enhanced permeability and retention (EPR) effects of tumor [10]. Furthermore, based on the receptor-mediated endocytosis, nanoparticles could exhibit active targeting effect after functionalization with cell recognizable targeting ligands, such as monoclonal antibodies [11], endogenous targeting peptides [12], and low molecular-weight compounds, such as folate [13].
Receptor-mediated endocytosis is one of the mechanisms through which nanoparticulate carriers can overcome the obstacle of BTB. The interleukin 13 receptor α2 (IL-13Rα2), one of the subunits of the interleukin-13 receptor, is encoded for a 65 kDa receptor protein. It is over-expressed on human tumors including established glioma cell lines and primary glioblastoma cell cultures [14], [15], [16], [17], [18], which makes IL-13Rα2 an attractive target. It has been reported that IL-13Rα2 can undergo internalization after binding to ligand without causing activation of its signaling pathways [19]. This property indicates that internalization of IL-13Rα2 is signal independent and IL-13Rα2 can be exploited for receptor-directed cancer therapy [19]. Based on the high affinity of IL-13Rα2 with IL13, IL13-PE38QQR, a conjugation complex of human IL-13 with a mutated form of Pseudomonas exotoxin, could effectively target tumor cell-specific recognition domains [20], [21], [22], [23] and show remarkable antitumor activity in animal models of several human cancers [24]. So it could be served as a promising targeted moiety for anti-glioma drug delivery [25].
Pep-1, a linear peptide with 9 amino acid residues (CGEMGWVRC), was isolated by a cyclic disulphide-constrained heptapeptide phages display library [26]. As a specific ligand of IL-13Rα2, Pep-1 could bind to IL-13Rα2 with high affinity and specificity, which was capable of crossing the BTB and homing to glioma [26]. As a new ligand, there is no previous study about Pep-1 conjugation to the drug delivery system which confers glioma targeting property through IL-13Rα2-mediated endocytosis by the glioma cells.
Based on IL-13Rα2 over-expression on glioma cells and the high affinity with Pep-1, Pep-1 can be used for enhancing delivery across the BTB and homing to glioma. In this study, Pep-1 was used as a targeting ligand to develop glioma targeting drug delivery system through chemical bonding with PEG-PLGA nanoparticle. In order to evaluate the in vitro and in vivo targeting efficacy of Pep-1 functionalized PEG-PLGA copolymer nanoparticle (Pep-NP), coumarin-6 was used as fluorescence probe to trace the targeting nanoparticles. The cellular uptake of Pep-NP by C6 glioma cells and the penetration ability into avascular C6 glioma spheroids were investigated. Furthermore, the in vivo biodistribution and brain targeting efficiency of Pep-NP was evaluated by intracranial glioma mice model.
Section snippets
Materials
Methoxyl poly(ethylene glycol)-co-poly(d,l-lactic-co-glycolic acid) copolymer (MePEG-PLGA, 40 KDa) and Maleimidyl-poly(ethylene glycol)-co-poly(d,l-lactic- co-glycolic acid) copolymer (Male-PEG-PLGA, 41.5 KDa) were synthesized by the ring opening polymerization as described before [27]. BCA kit, TritonX-100 and LysoTracker Red were purchased from Beyotime Biotechnology Co., Ltd. (Nantong, China). Penicillin-streptomycin, RPMI 1640 medium, fetal bovine serum (FBS) and 0.25% (w/v) trypsin
Synthesis of Pep-PEG-PLGA
The structure of Male-PEG-PLGA and Pep-PEG-PLGA were determined by 1H NMR spectroscopy. The solvent peak of CDCl3 was present at 7.26 ppm. In the spectrum of Male-PEG-PLGA, the maleimide group had the characteristic peak at 6.7 ppm (Fig. 1A), whereas disappeared after reaction with Pep-1 in the spectrum of Pep-PEG-PLGA (Fig. 1B), suggesting that Pep-1 was conjugated with Male-PEG-PLGA copolymer [31].
The FTIR spectra of Male-PEG-PLGA and Pep-PEG-PLGA were shown in Fig. 2. The spectrum of
Discussion
GBM is the most malignant form of primary astrocytic brain tumors in adults with a median overall survival (OS) of three months without standard treatment [32]. Several factors concur to make GBM treatment notoriously difficult. First, brain has a limited ability to repair itself, any damage may be irreversible. In addition, due to the aggressive growth of glioma, it is hard to completely remove the tumor by surgery. Last but not least, adequate penetration across the BTB by chemotherapeutics
Conclusion
In this study, we proposed PEG-PLGA nanoparticles modified with Pep-1 for glioma drug delivery via IL-13Rα2 mediated endocytosis. The Pep-1 peptide was conjugated to the surface of PEG-PLGA nanoparticles via a maleimide-thiol coupling reaction with the particle size of 94.25 ± 3.32 nm. Cellular experiments showed that Pep-NP significantly enhanced cellular uptake than that of unmodified NP and the internalization of Pep-NP was concentration-dependent, time-dependent and energy-dependent. More
Acknowledgments
This work was supported from the National Natural Science Foundation of China (81302710, 81273457), Natural Science Foundation of Jiangsu Province (BK2012445, BK2012843) and the ordinary university natural science research project of Jiangsu Province (13KJB350004). The authors also acknowledge the support from School of Pharmacy, Fudan University (SDD2012-4) & the Open Project Program of Key Lab of Smart Drug Delivery (Fudan University), Ministry of Education, China (SDD2012-4) and Science and
References (46)
- et al.
Targeted delivery of liposomal nanocontainers to the peritumoral zone of glioma by means of monoclonal antibodies against GFAP and the extracellular loop of Cx43
Nanomedicine
(2012) - et al.
Tumor vascular permeability and the EPR effect in macromolecular therapeutics: a review
J Control Release
(2000) - et al.
Folate-mediated delivery of macromolecular anticancer therapeutic agents
Adv Drug Deliv Rev
(2002) - et al.
A novel chimeric protein composed of interleukin 13 and Pseudomonas exotoxin is highly cytotoxic to human carcinoma cells expressing receptors for interleukin 13 and interleukin 4
J Biol Chem
(1995) - et al.
Targeting of interleukin-13 receptor on human renal cell carcinoma cells by a recombinant chimeric protein composed of interleukin-13 and a truncated form of Pseudomonas exotoxin A
Blood
(1996) - et al.
The interleukin-13 receptor α2 chain: an essential component for binding and internalization but not for interleukin-13-induced signal transduction through the STAT6 pathway
Blood
(2001) - et al.
Interleukin-13 fusion cytotoxin as a potent targeted drug for AIDS-Kaposi's sarcoma xenograft
Blood
(2000) - et al.
Angiopep-conjugated poly(ethylene glycol)-co-poly(ɛ-caprolactone) nanoparticles as dual-targeted drug delivery system for brain glioma
Biomaterials
(2011) - et al.
Odorranalectin-conjugated nanoparticles: preparation, brain delivery and pharmacodynamic study on Parkinson's disease following intranasal administration
J Control Release
(2011) - et al.
Precise glioma targeting of and penetration by aptamer and peptide dual-functioned nanoparticles
Biomaterials
(2012)
The enhanced permeability and retention (EPR) effect in tumor vasculature: the key role of tumor-selective macromolecular drug targeting
Adv Enzyme Regul
Anti-glioblastoma efficacy and safety of paclitaxel-loading Angiopep-conjugated dual targeting PEG-PCL nanoparticles
Biomaterials
Nanoparticles of 2-deoxy-D-glucose functionalized poly(ethylene glycol)-co-poly(trimethylene carbonate) for dual-targeted drug delivery in glioma treatment
Biomaterials
Folic acid mediated attenuation of loss of heterozygosity of DCC tumor suppressor gene in the colonic mucosa of patients with colorectal adenomas
Cancer Detect Prev
Targeting receptor-mediated endocytotic pathways with nanoparticles: rationale and advances
Adv Drug Deliv Rev
Use of nanoparticles for drug delivery in glioblastoma multiforme
Expert Rev Neurother
Evaluation of human brain tumor heterogeneity using multiple T1-based MRI signal weighting approaches
Magn Reson Med
Drug targeting to the brain
Pharm Res
A herpes simplex virus type 1 mutant deleted for gamma 34.5 and LAT kills glioma cells in vitro and is inhibited for in vivo reactivation
Cancer Gene Ther
Convection-enhanced delivery for the treatment of brain tumors
Expert Rev Neurother
Involvement of the low-density lipoprotein receptor-related protein in the transcytosis of the brain delivery vector angiopep-2
J Neurochem
Intracarotid infusion of RMP-7, a bradykinin analog: a method for selective drug delivery to brain tumors
J Neurosurg
Mannitol-facilitated CNS entry of rAAV2 vector significantly delayed the neurological disease progression in MPS IIIB mice
Gene Ther
Cited by (72)
Recent advances of nanomaterials for intervention in Parkinson's disease in the context of anti-inflammation
2024, Coordination Chemistry ReviewsA receptor-mediated landscape of druggable and targeted nanomaterials for gliomas
2023, Materials Today BioAdvances in antibody-based drugs and their delivery through the blood-brain barrier for targeted therapy and immunotherapy of gliomas
2023, International ImmunopharmacologyRecent Advances in the Therapeutic Strategies of Glioblastoma Multiforme
2022, NeuroscienceIn situ targeting nanoparticles-hydrogel hybrid system for combined chemo-immunotherapy of glioma
2022, Journal of Controlled ReleaseCitation Excerpt :However, the permeation of PTX across the brain tissue and glioma site is greatly restrained due to the existence of the BBB and the blood-brain tumor barrier (BBTB) [14]. To increase the accumulation of PTX in glioma tumor cells, a glutathione (GSH)-responsive prodrug nanoparticle (NPPTX) was designed and installed with the glioma targeting moiety (Pep-1 peptide) which could specifically bind to the interleukin 13 receptor α2 (IL-13Rα2) highly expressed on the surface of glioma [15]. Although glioma cells could indeed increase the uptake of nanocarriers through receptor-mediated endocytosis, intravenous injection did not substantially improve the absolute permeability of PTX into the brain.