Rare-earth-incorporated polymeric vector for enhanced gene delivery
Introduction
In recent years, two kinds of gene delivery systems for gene therapies: viral and non-viral [1] have been widely reported [2], [3]. Viral gene vectors have high efficiency, but serious safety risks such as immunogenicity, carcinogenicity and inflammation limit their clinical implementation [4]. In comparison, non-viral gene vectors with several advantages over viral ones such as low immunogenicity and toxicity, large DNA loading capacity, and tissue-specific targeting are typically less effective [2]. Therefore, it is critical to develop more efficient non-viral vectors for clinical applications [2], [5].
Among the various types of non-viral vectors, polyethylenimine (PEI), especially high-molecular weight (HMW) PEI (~25 kDa), is a widely used cationic polymer known as the gold standard [6]. Although HMW PEI (~25 kDa) has high gene transfection efficiency, the high toxicity remains a drawback for application in vivo [7]. Our previous studies have shown that β-cyclodextrin-polyethylenimine(PEI-CyD), in which β-CyD is crosslinked by low molecular weight PEI (600Da), has lower cytotoxicity than PEI 25 kDa and similar transfection efficiency as PEI 25 kDa [8]. Our preliminary studies suggest that the gene transfection efficiency of PEI-CyD can be improved by surface modification of the polymer [9], [10].
Metallic elements play vital roles in biological systems and activities, for example, bones and teeth [11], functional components of proteins [12], activators of enzymes [13], essential parts in the electron transport of the respiratory chain [14], and maintenance of normal functions in cell membranes [15]. In particular, rare earth elements (REEs) can change the mitochondrial metabolic activity [16], [17], promote DNA synthesis [18], regulate the activity of calmodulin [19], [20], and participate in a variety of physiological and biochemical processes [21]. Although REEs have been used to promote the growth and development of plants and animals [22], [23], their use in gene vectors have seldom been explored.
In this work, the benefits of metallic elements in biological processes such as DNA transcription, mRNA translation [24], [25], [26] and surface modification of polymeric materials by ion beams and plasmas [27], [28], [29] are combined. The cationic polymer PEI-CyD is doped with a rare earth element, neodymium (Nd), to produce Nd@PEI-CyD complexes. To determine the effects of the plasma treatments, the chemical, physical, and biological characteristics of the Nd@PEI-CyD are investigated. The transfection efficiency of Nd@PEI-CyD is compared to that of PEI-CyD and the commercial transfection agent Lipofectamine 2000. To illustrate the underlying mechanism (Fig. 1), the ATP assay is performed to evaluate the energy metabolism of cells and the reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis are conducted to assess several mRNA and proteins.
Section snippets
Materials
Branched polyethylenimine (PEI; average 25 000 Da), linear polyethylenimine (average MW 600), β-cyclodextrin (β-CyD, MW 1135), 1,10-carbonyldiimidazole (CDI, MW 162.15), dimethyl sulfoxide (DMSO, ≥99.5%), N,N-dimethylformanide (DMF, ≥99%), [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT, MW 218.1), phosphate buffered saline (PBS), and triethylamine (Et3N, 99%) were obtained from Sigma (St. Louis, MO, USA). DMF and DMSO were dried by refluxing over CaH2 and distilled before
Results and discussion
Fig. S1 depicts 1H NMR spectrum of PEI-CyD in D2O. Fig. 2A shows the tomoscan of the Nd@PEI-CyD samples. The modified surface darkens after the plasma treatment. The X-ray photoelectron spectroscopy (XPS) spectra of the Nd@PEI-CyD in Fig. 2B with different colors representing various depths show the Nd3d and O1s peaks. The O1s peak remains at about 532 eV at a depth of 100 nm (Fig. 2C), indicating the existence of C–O–H [31] and that the O–H bonds of PEI-CyD are unreacted. The O1s peak in the
Conclusion
A new type of gene vector, Nd@PEI-CyD which combines the rare-earth element Nd and non-viral polymeric gene vector, is obtained by plasma treatment and efficient delivery of DNA into cells is demonstrated. Nd@PEI-CyD exhibits a transfection efficiency of 58.6% which is dramatically higher than that of PEI-CyD without the plasma treatment and commercial transfection agent Lipofectamine 2000. The luciferase expression level mediated by Nd@PEI-CyD is 15 times and 27 times higher than that induced
Acknowledgments
This work was jointly supported by the National High Technology Development Program of China (863 Program 2007AA03Z355, 2009AA02Z416), National Natural Science Foundation of China (grant # 30970711 and 21074111), Major Scientific and Technological Innovation Project of Hangzhou (20122511A43), Hong Kong Research Grants Council (RGC) General Research Funds (GRF) Nos. 112510 and 112212, and City University of Hong Kong Applied Research Grants Nos. 9667066 and 9667069.
References (46)
- et al.
Controlled release systems for DNA delivery
Mol Ther
(2004) - et al.
Prospects for cationic polymers in gene and oligonucleotide therapy against cancer
Adv Drug Deliver Rev.
(2002) - et al.
Low-molecular-weight polyethylenimine as a non-viral vector for DNA delivery: comparison of physicochemical properties, transfection efficiency and in vivo distribution with high-molecular-weight polyethylenimine
J Control Releas
(2003) - et al.
Gene delivery to tumor cells by cationic polymeric nanovectors coupled to folic acid and the cell-penetrating peptide octaarginine
Biomaterials
(2011) - et al.
Initiation of mammalian protein synthesis: II. The assembly of the initiation complex with purified initiation factors
J Mol Biol
(1977) - et al.
Thionein (apometallothionein) can modulate DNA binding and transcription activation by zinc finger containing factor Spl
FEBS Lett
(1991) - et al.
XPS studies of the hybridization effects in RNi4B (R = Ce, Pr, Nd) compounds
Phys Lett A
(2003) - et al.
Preparation, characterization, photoactivity and XPS studies of Ln2ZrTiO7 (Ln = Sm and Nd)
Ceram Int
(2010) - et al.
A polyethylenimine-mimetic biodegradable polycation gene vector and the effect of amine composition in transfection efficiency
Biomaterials
(2013) - et al.
Studying biophysical barriers to DNA delivery by advanced light microscopy
Adv Drug Deliver Rev.
(2005)
An oligopeptide ligand-mediated therapeutic gene nanocomplex for liver cancer-targeted therapy
Biomaterials
Intracellular pathways and nuclear localization signal peptide-mediated gene transfection by cationic polymeric nanovectors
Biomaterials
Regulation of metallothionein gene expression by oxidative stress and metal ions
Biochem Pharmacol
Orally administrated rare earth element cerium induces metallothionein synthesis and increases glutathione in the mouse liver
Life Sci
Safer and virus-free?
Science
Design and development of polymers for gene delivery
Nat Rev Drug Discov
Viral vectors for gene therapy: the art of turning infectious agents into vehicles of therapeutics
Nat Med
Progress and problems with the use of viral vectors for gene therapy
Nat Rev Genet.
Low molecular weight polyethylenimines linked by beta-cyclodextrin for gene transfer into the nervous system
J Gene Med
FGF receptor-mediated gene delivery using ligands coupled to PEI-β-CyD
J Biomed Biotechnol
Calcium phosphate-based osteoinductive materials
Chem Rev.
Athletic induced iron deficiency: new insights into the role of inflammation, cytokines and hormones
Eur J Appl Physiol
Zinc coordination, function, and structure of zinc enzymes and other proteins
Biochemistry
Cited by (11)
Surface functionalization of biomaterials by plasma and ion beam
2018, Surface and Coatings TechnologyCitation Excerpt :Metallic elements such as lanthanides play essential roles in many physiological processes such as cell function promotion, metabolism regulation, and immune system maintenance [29]. The cationic polyethylenimine-β-cyclodextrin (PEI-CyD) has been incorporated with a rare earth element, Nd, by ion implantation to produce Nd@PEI-CyD with enhanced efficiency for plasmid DNA delivery [30]. Therapies combining chemotherapeutic drugs and nucleic acid have been developed to reverse MDR, but the lack of efficient drug nanocarriers is a major concern adversely affecting the therapeutic effectiveness.
Lanthanide-integrated supramolecular polymeric nanoassembly with multiple regulation characteristics for multidrug-resistant cancer therapy
2017, BiomaterialsCitation Excerpt :Last but not least, lanthanides can induce significant morphological changes, arrest the transition from G0/G1 to S state [23], and trigger the receptor-mediated extrinsic pathway of apoptosis [24]. Our recent study on the neodymium (Nd)-functionalized gene delivery vector reveals higher gene transfection activity by stimulation of the cellular energy metabolism and enhancement of cellular uptake ability [25]. We have also demonstrated that supramolecular cationic polyethyleneimine (PEI)-cyclodextrin conjugates are efficient carriers to encapsulate hydrophilic drugs via host-guest interactions and induce nucleic acid complexation by electrostatic interaction [26,27].
Evaluation the effect of thiamin deficiency on intestinal immunity of young grass carp (Ctenopharyngodon idella)
2015, Fish and Shellfish ImmunologyCitation Excerpt :Glutathione-S-transferase (GST) and glutathione reductase (GR) activities were determined as described by Gorbi et al. [24]. The lactate and adenosine triphosphate (ATP) contents were measured by the method described by Zhou et al. [47] and Wang et al. [48], respectively. The total RNA of intestine, head kidney, spleen and liver were extracted using RNAiso Plus Kit (Takara, Dalian, China) according to the manufacturer's instructions followed by DNase I treatment.
Improvement of corrosion resistance and biocompatibility of rare-earth WE43 magnesium alloy by neodymium self-ion implantation
2015, Corrosion ScienceCitation Excerpt :It has also been reported that Nd can enhance the corrosion resistance of magnesium alloys due to suppression of the galvanic effects by the intermetallic compounds [13,15,27,28] and the surface layer containing neodymium oxide [7,15,22,29]. In addition, Nd has been shown to be biocompatible as relatively high concentrations can be tolerated by various cell types [17,25,30]. In this work, without introducing extraneous elements, a small amount of Nd is ion implanted into WE43 Mg alloy and the effects on the corrosion resistance and biocompatibility as well as mechanisms are studied systematically.
The Cytotoxic and Genotoxic Assays of Mg-Ag Alloy Doped with Zn, Ca, and Nd Elements
2023, Journal of Materials Engineering and PerformanceMacrocyclic compounds for drug and gene delivery in immune-modulating therapy
2019, International Journal of Molecular Sciences
- 1
Both authors contributed equally to this work.