Article pubs.acs.org/molecularpharmaceutics
Alginate/CaCO3 Hybrid Nanoparticles for Efficient Codelivery of Antitumor Gene and Drug Dong Zhao, Chuan-Jun Liu, Ren-Xi Zhuo, and Si-Xue Cheng* Key Laboratory of Biomedical Polymers of Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, P. R. China
Mol. Pharmaceutics 2012.9:2887-2893. Downloaded from pubs.acs.org by UNIV OF THE SUNSHINE COAST on 06/27/18. For personal use only.
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ABSTRACT: In this study, a facile strategy for efficient codelivery of gene and drug was developed. Using a coprecipitation method, doxorubicin hydrochloride (DOX), an antitumor drug, and p53 expression plasmid were encapsulated in alginate/CaCO3/DNA/DOX nanoparticles with high encapsulation efficiency. The in vitro cell inhibition effect of the alginate/ CaCO3/DNA/DOX nanoparticles was evaluated by MTT assay in HeLa cells. The alginate/CaCO3/DNA/DOX nanoparticles exhibited a high cell inhibition rate about 80%, indicating that the alginate/CaCO3/DNA/DOX nanoparticles could effectively mediate gene transfection and deliver the drug to the cells. Compared with the codelivery of gene and drug, the treatments by alginate/CaCO3/DOX nanoparticles and alginate/CaCO3/ DNA nanoparticles separately led to much lower cell inhibition rates. Compared with the CaCO3/DNA/DOX nanoparticles without alginate modification, the alginate/CaCO3/DNA/DOX nanoparticles with a decreased particle size exhibited enhanced delivery efficiency. The alginate/CaCO3/DNA/DOX nanoparticles have promising applications in cancer treatments. KEYWORDS: drug delivery, gene transfer, calcium carbonate, alginate, nanoparticles
1. INTRODUCTION In recent years, clinical successes have led to a renewed interest in gene therapy. As one of the most promising approaches for the treatment of incurable diseases and genetic disorders, gene therapy has great importance in cancer therapy.1 In cancer treatments, existing chemotherapeutic drugs are far from perfect, with undesirable severe side effects, low bioavailability, and the development of drug resistance.2,3 To solve these problems, considerable research interest has been focused on the combined drug and gene therapy with a synergistic therapeutic effect.4−7 For example, drug resistance is mainly caused by malfunction of genes owing to chromosomal alterations in cancer cells.2,3 Simultaneous delivery of drugs and genes can enhance the drug sensitivity of cancer cells to achieve greater therapeutic effect.4−7 The purpose of the current study is to develop an efficient codelivery system for the codelivery of p53 antitumor gene and doxorubicin. As an tumor suppressor gene, the p53 gene plays a crucial role in diverse cellular activities, such as DNA repair, cell cycle regulation, and apoptosis.8,9 In addition to inhibiting p53 mutations, the reintroduction of wt p53 into tumor cells harboring p53 mutations may also enhance the sensitivity of tumor cells to chemotherapeutic agents through the inhibition of the P-gp expression related to drug resistance.7,10 On the other hand, wt p53 protein is positive in response to a variety of stress signals including DNA damage caused by antitumor drugs.11 Thus, the combination of p53 gene therapy and chemotherapy may increase the therapeutic efficacy in the treatment of cancers.7,10,11 Doxorubicin, which binds to DNA © 2012 American Chemical Society
by intercalation and induces a series of biochemical events inducing apoptosis in a number of different tumor cells, is among the most commonly used chemotherapeutic drugs in clinical use due to its excellent antitumor efficiency against various solid tumors.12,13 To efficiently deliver a therapeutic gene into target cells is the key issue in gene therapy. Although viral vectors are more effective, concerns over toxicity and production problems have limited their applications. Due to safety advantages, nonviral vectors have attracted increasing attention despite their relatively low transfection efficiency. For the gene and drug codelivery purpose, several promising systems including polymeric,14−16 liposomal,17,18 and silica-based nanoparticles19,20 have been developed. However, it is well-known that the biocompatibility of the widely investigated nonviral vectors based on cationic polymers and cationic liposomes is still not satisfactory. Compared to the widely investigated nonviral vectors based on cationic polymers and cationic liposomes, the technique of coprecipitation of Ca2+ with DNA in the presence of inorganic anions, such as CO32− and PO43−, has its great advantages in terms of safety and biocompatibility.21−27 In our previous study, to improve the stability and the transfection efficiency of CaCO3 coprecipitation based vectors, we introduced a natural polysaccharide, alginate, to the Received: Revised: Accepted: Published: 2887
April 17, 2012 July 21, 2012 August 15, 2012 August 15, 2012 dx.doi.org/10.1021/mp3002123 | Mol. Pharmaceutics 2012, 9, 2887−2893
Molecular Pharmaceutics
Article
Zetasizer (Nano ZS, Malvern Instruments). Prior to the measurement, 800 μL of deionized water was added to 200 μL of the freshly prepared solution containing nanoparticles for dilution. Data were given as mean ± standard deviation (SD) based on 3 independent measurements. The statistical significance between two sets of data was calculated using Student’s t test. A p value
