Targeted Delivery of Epirubicin to Cancer Cells by Polyvalent Aptamer System in vitro and in vivo

Enhanced theranostic efficacy of epirubicin-loaded SPION@MSN through co-delivery of an anti-miR-21-expressing plasmid and ZIF-8 hybridization to target colon adenocarcinoma

Using targeted drug delivery systems has emerged as a promising approach to increase the efficacy of chemotherapy, particularly in combination with gene therapy. The overexpression of miR-21 plays a crucial role in colorectal cancer (CRC) progression, and targeted inhibition of miR-21 offers significant potential for enhancing CRC chemotherapy outcomes. In this study, a theranostic system based on mesoporous silica and superparamagnetic iron oxide nanoparticles (SPION@MSNs) was synthesized as a core-shell structure. After loading epirubicin (EPI) in the open pores of MSN, the plasmid expressing anti-miR-21 (pDNA) covered the outer surface with the help of a ZIF-8 (zeolitic imidazolate framework-8) film. Afterward, polyethylene glycol (PEG) and AS1411 aptamer were conjugated to the surface to improve the protective, biocompatibility, and targeting abilities of the nanocarrier. Moreover, the physicochemical characteristics as well as the loading capacity and release profile of EPI and pDNA were fully evaluated. The uptake of the nanoparticles by CRC and normal cell lines in addition to the anticancer effects related to targeted combinational therapy were investigated in vitro. Finally, in vivo tests were performed on BALB/c mice bearing colorectal tumors to evaluate the effectiveness of the targeted nanoparticles, their possible side effects, and also their application in fluorescence and magnetic imaging in vivo. The successful synthesis of SPION@MSN-EPI/pDNA-ZIF-8-PEG-Apt nanoparticles (∼68 nm) and good loading efficiency and controlled release of EPI and pDNA were confirmed. Moreover, hemolysis and gel retardation assays demonstrated the biocompatibility and plasmid protection. Cellular uptake and expression of copGFP illustrated selective entry and transient transfection of targeted nanoparticles, consistent with the cytotoxicity results that indicated the synergistic effects of chemo-gene therapy. The results of animal studies proved the high antitumor efficiency of targeted nanoparticles with minimal tissue damage, which was in line with fluorescence and magnetic imaging results. The novel synthesized nanoparticles containing SPION@MSN-ZIF-8 were suitable for CRC theranostics, and the combined approach of chemo-gene therapy suppressed the tumor more effectively.

Improving Chemotherapy Effectiveness: Utilizing CuS Nanoparticles Coated with AS1411 Aptamer and Chitosan for Targeted Delivery of Doxorubicin to Cancerous Cells

Here, a novel targeted nanostructure complex was designed as an alternative to the traditional treatment approaches for breast cancer. A delivery system utilizing CuS nanoparticles (CuS NPs) was developed for the purpose of targeted administration of doxorubicin (Dox), an anticancer agent. To regulate Dox release, chitosan (CS), a biodegradable and hydrophilic polymer with biocompatible properties, was applied to coat the Dox-loaded CuS NPs. Furthermore, AS1411 aptamer, served as a targeting agent for breast cancer cells (MCF-7 and 4T1 cells), was conjugated with CS-Dox-CuS NPs effectively. To assess the effectiveness of APT-CS-CuS NPs, various methods such as flow cytometry analysis, MTT assay, fluorescence imaging, and in vivo antitumor efficacy were employed. The hollow core and porous surface of CuS NPs improved the Dox loading capacity and entrapment efficiency (almost 100%). The rate of drug release at the tumor site (citrate buffer with pH 5.6) exhibited a marked increase in comparison to that observed within the physiological environment (phosphate buffer with pH 7.4). The targeted formulation (APT-CS-Dox-CuS NPs) significantly increased cytotoxicity of the Dox payload in target cells, including 4T1 (p ≤ 0.0001 (****)) and MCF7 (p ≤ 0.01 (**)) cells compared to CHO cells. Moreover, the ability of tumor growth inhibition of the targeted system was significantly (p ≤ 0.05 (*)) more than free Dox in tumor-bearing mice. The findings indicate that the targeted formulation augmented effectiveness and specificity while minimizing harm to non-targeted cells, signifying its potential as a sophisticated cancer drug delivery system.

Targeted delivery of epirubicin to cancerous cell using copper sulphide nanoparticle coated with polyarginine and 5TR1 aptamer

Chemotherapy has been widely acknowledged as a primary approach for cancer treatment. However, the administration of chemotherapy agents is often limited by their adverse effects that result from an inability to distinguish between healthy and malignant cells. As such, utilising nanocarriers in targeted drug delivery can significantly reduce these side effects while enhancing therapeutic efficacy. Herein, we developed copper sulphide nanoparticles (CuSNPs) loaded with epirubicin (Epi) coated by polyarginine and 5TR1 aptamer (CEPA) to target mucin-1 which is overexpressed on various types of cancer cells. MTT results revealed that CEPA significantly induced cytotoxicity of the drug in desired cell lines (C26 and MCF-7, mucin+) compared to CEPA-treated CHO cells (non-target, mucin-), verifying the targeting ability of CEPA complex. The obtained results from both flow cytometry analysis and cell imaging demonstrated that CEPA complex had successful internalisation in both target cell lines but no internalisation in CHO cell line. The result of in vivo assay showed more tumour inhibition and more accumulation in tumour tissue for CEPA complex in comparison to free Epi. To conclude, the CEPA complex has demonstrated superior efficacy and fewer adverse reactions compared to Epi. This indicates a promising and effective strategy for treating cancer.

Aptamer-Based Probes for Cancer Diagnostics and Treatment

Aptamers are single-stranded DNA or RNA oligomers that have the ability to generate unique and diverse tertiary structures that bind to cognate molecules with high specificity. In recent years, aptamer researches have witnessed a huge surge, owing to its unique properties, such as high specificity and binding affinity, low immunogenicity and toxicity, and simplicity of synthesis with negligible batch-to-batch variation. Aptamers may bind to targets, such as various cancer biomarkers, making them applicable for a wide range of cancer diagnosis and treatment. In cancer diagnostic applications, aptamers are used as molecular probes instead of antibodies. They have the potential to detect various cancer-associated biomarkers. For cancer therapeutic purposes, aptamers can serve as therapeutic or delivery agents. The chemical stabilization and modification strategies for aptamers may expand their serum half-life and shelf life. However, aptamer-based probes for cancer diagnosis and therapy still face several challenges for successful clinical translation. A deeper understanding of nucleic acid chemistry, tissue distribution, and pharmacokinetics is required in the development of aptamer-based probes. This review summarizes their application in cancer diagnostics and treatments based on different localization of target biomarkers, as well as current challenges and future prospects.

Multivalent Aptamer Approach: Designs, Strategies, and Applications

Aptamers are short and single-stranded DNA or RNA molecules with highly programmable structures that give them the ability to interact specifically with a large variety of targets, including proteins, cells, and small molecules. Multivalent aptamers refer to molecular constructs that combine two or more identical or different types of aptamers. Multivalency increases the avidity of aptamers, a particularly advantageous feature that allows for significantly increased binding affinities in comparison with aptamer monomers. Another advantage of multivalency is increased aptamer stabilities that confer improved performances under physiological conditions for various applications in clinical settings. The current study aims to review the most recent developments in multivalent aptamer research. The review will first discuss structures of multivalent aptamers. This is followed by detailed discussions on design strategies of multivalent aptamer approaches. Finally, recent developments of the multivalent aptamer approach in biosensing and biomedical applications are highlighted.

Targeted drug delivery vehicles mediated by nanocarriers and aptamers for posterior eye disease therapeutics: barriers, recent advances and potential opportunities

Nanomedicine and aptamer have excellent potential in giving play to passive and active targeting respectively, which are considered to be effective strategies in the retro-ocular drug delivery system. The presence of closely adjoined tissue structures in the eye makes it difficult to administer the drug in the posterior segment of the eye. The application of nanomedicine could represent a new avenue for the treatment, since it could improve penetration, achieve targeted release, and improve bioavailability. Additionally, a novel type of targeted molecule aptamer with identical objective was proposed. As an emerging molecule, aptamer shows the advantages of penetration, non-toxicity, and high biocompatibility, which make it suitable for ocular drug administration. The purpose of this paper is to summarize the recent studies on the effectiveness of nanoparticles as a drug delivery to the posterior segment of the eye. This paper also creatively looks forward to the possibility of the combined application of nanocarriers and aptamers as a new method of targeted drug delivery system in the field of post-ophthalmic therapy.

CircEAF2 counteracts Epstein-Barr virus-positive diffuse large B-cell lymphoma progression via miR-BART19-3p/APC/β-catenin axis

Background

Epstein-Barr virus (EBV) represents an important pathogenic factor of lymphoma and is significantly associated with poor clinical outcome of diffuse large B-cell lymphoma (DLBCL). Circular RNAs (circRNAs) play an essential role in lymphoma progression. However, the underlying mechanism of circRNA on DLBCL progression related to EBV remains largely unknown.

Methods

CircRNA was screened by high-throughput sequencing in tumor samples of 12 patients with DLBCL according to EBV infection status. Expression of circEAF2, as well as the relationship with clinical characteristics and prognosis, were further analyzed in tumor samples of 100 DLBCL patients using quantitative real-time PCR. Gain- and loss-of-function experiments were conducted to investigate the biological functions of circEAF2 both in vitro and in vivo. The underlying mechanism of circRNA on DLBCL progression were further determined by RNA sequencing, RNA pull down assay, dual-luciferase reporter assay, rescue experiments and western blotting.

Results

We identified a novel circRNA circEAF2, which was downregulated in EBV + DLBCL and negatively correlated with EBV infection and DLBCL progression. In EBV-positive B lymphoma cells, circEAF2 overexpression induced lymphoma cell apoptosis and sensitized lymphoma cells to epirubicin. As mechanism of action, circEAF2 specifically targeted EBV-encoded miR-BART19-3p, upregulated APC, and suppressed downstream β-catenin expression, resulting in inactivation of Wnt signaling pathway and inhibition of EBV + DLBCL cell proliferation. In EBV-positive B-lymphoma murine models, xenografted tumors with circEAF2 overexpression presented decreased Ki-67 positivity, increased cell apoptosis and retarded tumor growth.

Conclusions

CircEAF2 counteracted EBV + DLBCL progression via miR-BART19-3p/APC/β-catenin axis, referring circEAF2 as a potential prognostic biomarker. Therapeutic targeting EBV-encoded miRNA may be a promising strategy in treating EBV-associated lymphoid malignancies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01458-9.

Aptamer-based ATP-responsive delivery systems for cancer diagnosis and treatment

In recent years, many stimuli-triggered drug delivery platforms have been designed to deliver drugs accurately to specific sites and reduce their side effects, improving "on-demand" therapeutic efficacy. Adenosine-5'-triphosphate (ATP)-responsive drug delivery methods are examples of these systems that use ATP molecules as a trigger for delivery of therapeutic agents. Since intra- and extra-cellular ATP concentrations are significantly different from each other (1-10 mM and <0.4 mM, respectively), the use of ATP can be a practical method for regulating drug release. Aptamers possess unique properties including, ligand-specific response, short sequence (~ 20-80 bases) and easy functionalization. Thus, their combination with ATP-responsive systems results in more accurate drug delivery systems and greater control of drug release. A wide range of nanoparticles, such as polymeric nanogels, liposomes, metallic nanoparticles, protein, or DNA nano-assemblies, have been employed in the fabrication of nanocarriers. In this review, we describe several ATP-responsive drug delivery systems based on the various carriers and discuss the challenges and strengths of each method.

Nonspecific nuclear uptake of anti-MUC1 aptamers by dead cells: the role of cell viability monitoring in aptamer targeting of membrane-bound protein cancer biomarkers

Most aptamers targeting cell-expressed antigens are intended for in vivo application, however, these sequences are commonly generated in vitro against synthetic oligopeptide epitopes or recombinant proteins. As these in vitro analogues frequently do not mimic the in vivo target within an endogenous environment, the evolved aptamers are often prone to nonspecific binding. The presence of dead cells and cellular debris further complicate aptamer targeting, due to their high nonspecific affinities to single-stranded DNA. Despite these known limitations, assessment of cell viability and/or the removal of dead cells is rarely applied as part of the methodology during in vivo testing of aptamer binding. Furthermore, the extent and route(s) by which dead cells uptake existing aptamers remains to be determined in the literature. For this purpose, the previously reported aptamer sequences 5TR1, 5TR4, 5TRG2 and S22 - enriched against the MUC1 tumour marker of the mucin glycoprotein family - were used as model sequences to evaluate the influence of cell viability and the presence of nontarget cell-expressed protein on aptamer binding to the MUC1 expressing human cancer cell lines MCF-7, Hs578T, SW480, and SW620. From fluorescence microscopy analysis, all tested aptamers demonstrated extensive nonspecific uptake within the nuclei of dead cells with compromised membrane integrities. Using fluorescent-activated cell sorting (FACS), the inclusion of excess double-stranded DNA as a blocking agent showed no effect on nonspecific aptamer uptake by dead cells. Further nonspecific binding to cell-membrane bound and intracellular protein was evident for each aptamer sequence, as assessed by southwestern blotting and FACS. These factors likely contributed to the ∼120-fold greater binding response of the 5TR1 aptamer to dead MCF-7 cells over equivalent live cell populations. The identification of dead cells and cellular debris using viability stains and the subsequent exclusion of these cells from FACS analysis was identified as an essential requirement for the evaluation of aptamer binding specificity to live cell populations of the cancer cell lines MCF-7, Hs578T and SW480. The research findings stress the importance of dead cell uptake and more comprehensive cell viability screening to validate novel aptamer sequences for diagnostic and therapeutic application.

Co-delivery of doxorubicin and aptamer against Forkhead box M1 using chitosan-gold nanoparticles coated with nucleolin aptamer for synergistic treatment of cancer cells

Herein, a nanotherapeutic delivery method was presented for co-delivery of doxorubicin (DOX) and aptamer against Forkhead box M1 (FOXM1 Apt) to cancer cells. Firstly, the vehicle composed of chitosan (CS)-Gold nanoparticles (AuNPs) conjugate was prepared. Nucleolin aptamer (AS1411) and FOXM1 Apt were loaded onto the CS-AuNPs and formed Aptamers (Apts)-CS-AuNPs. Subsequently, DOX was added to the Apts-CS-AuNPs to obtain the DOX-Apts-CS-AuNPs complex for synergistic treatment of tumor. The data of flow cytometry analysis and fluorescence imaging displayed that the complex was effectively internalized into target cells (A549 and 4T1 cells, nucleolin+) but not into CHO cells as nontarget cells. The results of the MTT assay showed that the complex significantly increased cell mortality in 4T1 and A549 cells compared to CHO cells treated with the complex. The in vivo studies demonstrated that the DOX-Apts-CS-AuNPs complex exhibited more tumor inhibitory effect and less distribution in other organs compared to free DOX.

Aptamer-conjugated PLGA nanoparticles for delivery and imaging of cancer therapeutic drugs

Most problems associated with chemotherapeutic agents involve non-specific cytotoxicity, low intratumoral accumulation and drug resistance. Targeted drug delivery systems (TDDS) based on nanoparticles (NPs) are a new strategy for better therapeutic efficiency, along with reduction of side effects commonly seen with cancer drugs. Poly (lactic-co-glycolic acid) (PLGA), as one of the furthest developed synthetic polymer, has gained significant attention because of excellent properties-including biodegradability and biocompatibility, controlled release of drug, protection of drug or gene from decomposition and ability to modify surface with targeting agents for both cancer diagnosis and therapy. Aptamers are single-stranded RNA or DNA that can fold through intramolecular interactions into specific three-dimensional structures to selectively and exclusively bind with interested biomarkers. In this review, we explain the latest developments regarding the application of aptamer-decorated PLGA NPs in delivery of therapeutic agents or cancer-related genes into cancer cells. Additionally, we discuss the most recent efforts in the field of aptamer-grafted PLGA-based NPs as theranostics and stimuli-responsive agents.

Therapeutic applications of AS1411 aptamer, an update review

Nucleolin or C23, is one of the most abundant non-ribosomal phosphoproteins of nucleolus. However, in several cancers, nucleolin is highly expressed both intracellularly and on the cell surface. So, it is considered as a potential target for the diagnosis and cancer therapy. Targeting nucleolin by compounds such as AS1411 aptamer can reduce tumor cell growth. In this regard, interest has increased in nucleolin as a molecular target for overcoming cancer therapy challenges. This review paper addressed recent progresses in nucleolin targeting by the G-rich AS1411 aptamer in the field of cancer therapy mainly over the past three years.

Aptamer-Based Targeted Drug Delivery Systems: Current Potential and Challenges

Aptamers are single-stranded DNA or RNA with 20-100 nucleotides in length that can specifically bind to target molecules via formed three-dimensional structures. These innovative targeting molecules have attracted an increasing interest in the biomedical field. Compared to traditional protein antibodies, aptamers have several advantages, such as small size, high binding affinity, specificity, good biocompatibility, high stability and low immunogenicity, which all contribute to their wide application in the biomedical field. Aptamers can bind to the receptors on the cell membrane and mediate themselves or conjugated nanoparticles to enter into cells. Therefore, aptamers can be served as ideal targeting ligands for drug delivery. Since their excellent properties, different aptamer-mediated drug delivery systems had been developed for cancer therapy. This review provides a brief overview of recent advances in drug delivery systems based on aptamers. The advantages, challenges and future prospectives are also discussed.

Design and synthesis of aptamer AS1411-conjugated EG@TiO2@Fe2O3nanoparticles as a drug delivery platform for tumor-targeted therapy

AS1411@GMBS@EG@TiO₂@Fe₂O₃nanoparticle is an effective and safe pH-responsive sustained release system for targeted drug delivery into nucleolin-positive cells.

64Cu-Labeled Aptamers for Tumor-Targeted Radionuclide Delivery

Aptamers are a class of oligonucleotides with high binding affinity and specificity with their targets. Additionally, aptamers are nontoxic, very thermally stable, and able to reversibly undergo denaturation and have a small size. Cancer-related aptamers can be used for tumor-targeted drug delivery, such as to deliver diagnostic and therapeutic radionuclides to target cancers. We describe the process for preparing a ⁶⁴Cu-labeled modified A10 aptamer to target prostate cancer by conjugating and radiolabeling. The modified A10 aptamer was conjugated with p-SCN-Bn-NOTA as the chelator. Following this, the aptamer can be radiolabeled with the ⁶⁴Cu radioisotope. NOTA was selected as the chelator of choice due to its commercial availability and widely demonstrated in vivo stability with the ⁶⁴Cu radioisotope. Using this system, prostate cancer could potentially be targeted for noninvasive imaging using positron emission tomography (PET). Closely following this protocol allows many aptamers to be successfully radiolabeled to accurately and quantitatively trace their distribution in vivo for a wide range of medical applications.

DNA origami-based aptasensors

Traditional analytical techniques face many limitations such as time-consuming process, complicated sample preparation, high consumption of reagents and need for expensive equipment. So, it is important that simple, rapid and sensitive detection methods are introduced. Nucleic acids-based assays, particularly aptamers, have a great impact on modern life sciences for biological analysis and target detection. Aptamer-based biosensors with unique recognition properties including high specificity and affinity, rapid response and simple fabrication have attracted much attention. It is believed that two- and three-dimensional structures, sometimes referred to as DNA origami, using DNA aptamers can show more selective binding affinity and better stability over other nucleic acids forms. In this review, we will focus on recent advances in the development and uses of electrochemical and optical DNA origami-based aptasensors to supply readers with a comprehensive understanding of their improvements. Also, the challenges and awards of these approaches are discussed.

Smart aptamer-modified calcium carbonate nanoparticles for controlled release and targeted delivery of epirubicin and melittin into cancer cells in vitro and in vivo

To explore the effect of combination therapy of epirubicin (Epi) and melittin (Mel) to cancer cells, calcium carbonate nanoparticles (CCN), as carriers, were developed which were modified with MUC1-Dimer aptamers as targeting agents. Both Epi and Mel were delivered at the same time to cancer cells overexpressing the target of MUC1 aptamer, mucin 1 glycoproteins (MCF7 and C26 cells). CCN were prepared with a water-in-oil emulsion method. Epi and Mel were separately encapsulated in CCN and the nanoparticles were modified with MUC1-Dimer aptamers. In vitro studies, including MTT assay, flow cytometry analysis and fluorescence imaging were applied to investigate the targeting and cell proliferation inhibition capabilities of MUC1-Dimer aptamer-CCN-Mel complex and MUC1-Dimer aptamer-CCN-Epi complex in the target (MCF-7 and C26 cells) and nontarget (HepG2) cells. Also, the function of the developed complexes was analyzed using in vivo tumor growth inhibition. The release of Epi from MUC1-Dimer aptamer-CCN-Epi complex was pH-sensitive. Cellular uptake studies showed more internalization of the MUC1-Dimer aptamer-CCN-Epi complex into MCF-7 and C26 cells (target) compared to HepG2 cells (nontarget). Interestingly, the MUC1-Dimer aptamer-CCN-Mel complex and MUC1-Dimer aptamer-CCN-Epi complex indicated very low toxicity as compared to target cells. Moreover, co-delivery of Epi and Mel using the mixture of MUC1-Dimer aptamer-CCN-Mel complex and MUC1-Dimer aptamer-CCN-Epi complex exhibited strong synergistic cytotoxicity in MCF-7 and C26 cells. Furthermore, the presented complexes had a better function to control tumor growth in vivo compared to free Epi.

Targeted delivery of doxorubicin to cancer cells by a cruciform DNA nanostructure composed of AS1411 and FOXM1 aptamers

OBJECTIVES

Here, a novel cruciform DNA nanostructure was developed for targeted delivery of doxorubicin (Dox), as an anticancer agent, to lung (A549 cells) and breast (4T1 cells) cancer cells. The cruciform DNA nanostructure consisted of AS1411 aptamer as targeting agent and Forkhead Box Protein M1(FOXM1) aptamer as therapeutic agent.

METHODS

MTT assay, fluorescence imaging, flow cytometry analysis, and in vivoantitumor efficacy were performed to evaluate the function of the Dox-DNA nanostructure complex.

RESULTS

The presented delivery system benefited from tumor targeting, high stability in serum and simple construction. The Dox-DNA nanostructure complex showed a noticeable higher internalization degree into A549 and 4T1 cells (target), overexpressing nucleolin on their cell membranes, compared to CHO cells (nontarget, nucleolin negative). Moreover, the results of MTT assay exhibited that Dox-DNA nanostructure complex significantly decreased cell viability in A549 and 4T1 cells compared to CHO cells, which significantly preserved their viability. Besides, Dox-DNA nanostructure complex significantly reduced tumor growth in tumor-bearing mice in comparison with Dox and DNA nanostructure treatments.

CONCLUSION

These findings confirmed that synergistic combination of FOXM1 aptamer and Dox into Dox-DNA nanostructure complex enhanced antitumor effectiveness and reduced toxicity toward nontarget cells, opening up new insights in cancer treatment.

Synthetic routes to nanomaterials containing anthracyclines: noncovalent systems

Chemotherapy still constitutes a basic treatment for various types of cancer. Anthracyclines are effective antineoplastic drugs that are widely used in clinical practice. Unfortunately, they are characterized by high systemic toxicity and lack of tumour selectivity. A promising way to enhance treatment effectiveness and reduce toxicity is the synthesis of systems containing anthracyclines either in the form of complexes for the encapsulation of active drugs or their covalent conjugates with inert carriers. In this respect nanotechnology offers an extensive spectrum of possible solutions. In this review, we discuss recent advances in the development of anthracycline prodrugs based on nanocarriers such as copolymers, lipids, DNA, and inorganic systems. The review focuses on the chemical architecture of the noncovalent nanocarrier-drug systems.

A Novel AS1411 Aptamer-Based Three-Way Junction Pocket DNA Nanostructure Loaded with Doxorubicin for Targeting Cancer Cells in Vitro and in Vivo

Active targeting of nanostructures containing chemotherapeutic agents can improve cancer treatment. Here, a three-way junction pocket DNA nanostructure was developed for efficient doxorubicin (Dox) delivery into cancer cells. The three-way junction pocket DNA nanostructure is composed of three strands of AS1411 aptamer as both a therapeutic aptamer and nucleolin target, the potential biomarker of prostate (PC-3 cells) and breast (4T1 cells) cancers. The properties of the Dox-loaded three-way junction pocket DNA nanostructure were characterized and verified to have several advantages, including high serum stability and a pH-responsive property. Cellular uptake studies showed that the Dox-loaded DNA nanostructure was preferably internalized into target cancer cells (PC-3 and 4T1 cells). MTT cell viability assay demonstrated that the Dox-loaded DNA nanostructure had significantly higher cytotoxicity for PC-3 and 4T1 cells compared to that of nontarget cells (CHO cells, Chinese hamster ovary cell). The in vivo antitumor effect showed that the Dox-loaded DNA nanostructure was more effective in prohibition of the tumor growth compared to free Dox. These findings showed that the Dox-loaded three-way junction pocket DNA nanostructure could significantly reduce the cytotoxic effects of Dox against nontarget cells.

Targeted co-delivery of epirubicin and NAS-24 aptamer to cancer cells using selenium nanoparticles for enhancing tumor response in vitro and in vivo

Chemotherapy is a commonly used cancer treatment strategy that causes severe side effects by damaging normal tissue. Therefore, targeted drug delivery systems have attracted great attention for the treatment of cancer in recent years. In this study, epirubicin (EPI)-loaded-NAS-24-functionalized PEI-PEG-5TR1 aptamer coated selenium nanoparticles (SeNPs), known as the ENPPASe complex, were developed and used for targeted delivery of both EPI (anticancer drug) and NAS-24 aptamer (apoptosis induction agent) to MCF7 (human breast carcinoma cell) and C26 (murine colon carcinoma cell) cancer cells using 5TR1 aptamer as the target agent. The ENPPASe complex could significantly reduce the toxicity in non-target cells (HEPG2, hepatocellular carcinoma cell). As with the EPI alone, the ENPPASe complex could significantly reduce cell viability in the target cancer cells (MCF-7 and C26). In addition, the complex significantly reduced the tumor growth in cancer-bearing mice compared to EPI treatment alone.

Tetrac-conjugated polymersomes for integrin-targeted delivery of camptothecin to colon adenocarcinoma in vitro and in vivo

In this study, we prepared tetraiodothyroacetic acid (tetrac) conjugated PEG-PLGA polymersomes for the targeted delivery of camptothecin to colon adenocarcinoma. Tetrac, which binds to integrin α_vβ₃ with high affinity and specificity, was covalently conjugated to the surface of the PEGylated polymersomal formulation of camptothecin (CPT). The hydrodynamic and morphological properties of the prepared system were evaluated using TEM (transmission electron microscopy), SEM (scanning electron microscopy) and DLS (dynamic light scattering) experiments. Camptothecin was encapsulated in the polymersomal system with encapsulation efficiency and loading content of 84±10.12 and 4.2±0.82, respectively. The in vitro release profile of camptothecin from the polymersomal formulation revealed the sustained release pattern. In vitro cytotoxicity experiments confirmed that the tetrac-conjugated camptothecin loaded-polymersomes had higher cellular toxicity towards integrin-overexpressed HT29 and C26 colorectal cancer cells than integrin-negative CHO cell line. The in vivo tumor inhibitory effect of tetrac-conjugated camptothecin loaded-polymersomes demonstrated an enhanced therapeutic index of integrin targeted polymersomal formulation over both non-targeted polymersomal formulation and free camptothecin in C26 tumor bearing mice. The obtained results demonstrated that the prepared tetrac-conjugated polymersomes were able to control the release of camptothecin, and significantly increase the therapeutic index of compthotecin. This study demonstrates the versatility of integrin-targeted tetrac-conjugated PEG-PLGA polymersomal formulation as an anti-cancer nano-pharmaceutical platform.

A novel chemotherapy drug-free delivery system composed of three therapeutic aptamers for the treatment of prostate and breast cancers in vitro and in vivo

In this study, a novel chemotherapy drug-free DNA nanocomplex composed of three therapeutic aptamers (IDA, AS1411 and apMNK2F) was designed for treatment of cancer cells. For MTT assay, PC-3 and 4T1 cells (target cells) and CHO cells (nontarget cells) were treated with apMNK2F-AS1411-IDA complex (DNA nanocomplex), as well as AS1411, IDA and apMNK2F alone. Internalization of apMNK2F-AS1411-IDA complex was analyzed by fluorescence imaging and flow cytometry analysis. In the last step, the presented DNA nanocomplex was applied for prohibition of tumor growth in vivo. The results of internalization assay verified that the developed apMNK2F-AS1411-IDA complex was remarkably internalized into PC-3 and 4T1 cells, but not into CHO cells. The results of internalization assay was confirmed by MTT assay. apMNK2F-AS1411-IDA complex was more cytotoxic in PC-3 and 4T1 cells (target) and less cytotoxic in CHO cells (nontarget). Also, the DNA nanocomplex could effectively suppress the growth of tumors in vivo.

Smart AS1411-aptamer conjugated pegylated PAMAM dendrimer for the superior delivery of camptothecin to colon adenocarcinoma in vitro and in vivo

In the current study camptothecin-loaded pegylated PAMAM dendrimer were synthesized and were functionalized with AS1411 anti-nucleolin aptamers for site-specific targeting against colorectal cancer cells which over expresses nucleolin receptors. The morphological properties and size dispersity of the prepared nanoparticles were evaluated using transmission electron microscope (TEM) and DLS. The drug-loading content and encapsulation efficiency were obtained 8.1% and 93.67% respectively. The in vitro release of camptothecin from the formulation was provided the sustained release of encapsulated camptothecin during 4days. Comparative in vitro cytotoxicity experiments demonstrated that the targeted camptothecin loaded-pegylated dendrimers had higher antiproliferation activity, towards nucleolin-positive HT29 and C26 colorectal cancer cells than nucleolin-negative CHO cell line. Fluorscence microscopy and flow cytometry also confirmed the enhanced cellular uptake of AS1411 targeted pegylated-dendrimer. In vivo study in C26 tumor-bearing BALB/C mice revealed that the AS1411-functionalized camptothecin loaded pegylated dendrimers improved antitumor activity and survival rate of the encapsulated camptothecin. Conjugation of AS1411 aptamer to the camptothecin loaded-pegylated dendrimer surface provides site-specific delivery of camptothecin, inhibit C26 tumor growth in vivo and significantly decrease systemic toxicity. These results suggested that the new nucleolin-targeted pegylated PAMAM dendrimer as a delivery system for camptothecin have the potential for the treatment of nucleolin-overexpressed colorectal cancer.