Development of an effective liposomal cholesterol ester transfer protein (CETP) vaccine for protecting against atherosclerosis in rabbit model

Clinical trials of cholesterol ester transfer protein (CETP) peptide vaccine were stopped after disappointing results in humans due to the inadequacy of adjuvant aluminum hydroxide in stimulating the immune response against the self-antigen of CETP. To increase the efficacy of the CETP vaccine, we developed a novel liposomal form of tetanus toxoid-CETP (TT-CETP) peptide (Lip CETP) with well-characterized properties and high encapsulation efficiency. The vaccine efficacy against atherosclerosis was evaluated in rabbits challenged with a high cholesterol diet. Rabbits were immunized with Lip-CETP or liposome containing CETP with CpG ODN (Lip CETP/CpG). Control groups received empty liposomes or buffer. Anti-TT-CETP specific antibodies in serum were determined and gene expression of cytokine IFN-γ and IL-4 were measured in blood peripheral mononuclear cells. Therapeutic response was evaluated by titration of plasma lipoproteins during the study and pathologic analysis of aorta atherosclerotic lesions at the end. Lip-CETP/CpG elicited strong anti-TT-CETP antibodies and a higher IFN-γ level than the buffer. IL-4 was lower than the buffer in all vaccinated groups. Plasma lipoproteins showed no significant difference in the studied groups. Atherosclerosis thickness grade of the aorta was lower than the buffer group (p < 0.001) in rabbits vaccinated with Lip-CETP but not with Lip-CETP/CpG. In conclusion, Lip-CETP showed a strong atheroprotective effect.

Na+/K+ ATPase-targeted delivery to metastatic breast cancer models

In this study, we reported doxorubicin (DOX)-encapsulated nanoparticles (NPs) formulated with biocompatible and biodegradable poly (lactic-co-glycolic acid) (PLGA) and modified with a 13-amino acid peptide (S3) against sodium/potassium (Na⁺/K⁺)-ATPase pump alpha subunit to investigate its potential as antitumor agent. The morphological properties and size dispersity of the prepared nanoparticles were evaluated using scanning electron microscope (SEM) and dynamic light scattering (DLS). The encapsulation efficiency and in vitro release during 7 days were evaluated. Comparative in vitro cytotoxicity experiments demonstrated that the S3-conjugated nanoparticles (S3-PLGA-DOX NPs) had higher antiproliferative activity. Flow cytometry analysis confirmed the enhanced cellular uptake of S3-PLGA-DOX NPs in comparison with PLGA-DOX. In vivo study in 4T1 tumor-bearing BALB/C mice revealed that the S3-functionalized DOX-loaded NPs improved antitumor activity and survival rate of 4T1 tumor bearing mice. In this regard, conjugation of S3 peptide to the surface of DOX-loaded PLGA NPs provides site-specific delivery of DOX, inhibits 4T1 tumor growth in vivo and significantly decreases systemic toxicity. The obtained results suggested that the new (Na⁺/K⁺)-ATPase pump-targeted PLGA NPs as a target-selective delivery system for DOX has great potential for the treatment of breast cancer.

Hybrid carbon-based materials for gene delivery in cancer therapy

Accumulation at tumor tissue without any damage to healthy normal tissues is an ultimate goal in cancer therapy. Despite many efforts in the field of cancer therapy, this disease remains as the major reason of mortality all over the world. Gene therapy has introduced great opportunity to fight against cancer disease. It should be noted that still some obstacles limit clinical application of gene delivery approach, which have to be overcome for efficient transportation of therapeutic gene to the site of action. In this regard, carbon nanomaterials and their unique physical and chemical properties such as their capability of DNA protection have attracted much attention in the field of nanomedicine and non-viral carriers for therapeutic genes. Although, negligible solubility of carbon nanomaterials in biological environments has limited their biomedical application but their structural characteristics facilitate their chemical modifications thereby overcoming their solubility problem. Moreover, hybridization of modified carbon materials with different polymers provides more biocompatible and capable systems for gene delivery purposes. In the current review, we summarized hybrid carbon-based materials as non-viral carriers for gene delivery.

An ultrasensitive electrochemical sensing method for detection of microcystin-LR based on infinity-shaped DNA structure using double aptamer and terminal deoxynucleotidyl transferase

This study develops a novel electrochemical sensing platform for microcystin-LR (MC-LR) detection. This aptasensor comprises the hybridization of double aptamer to its complementary strand (CS) on the surface of electrode and generation of an Infinity-shaped DNA structure in the absence of target by terminal deoxynucleotidyl transferase (TdT). The formation of Infinity-shaped construction leads to the development of an ultrasensitive aptasensor for MC-LR detection. In the presence of MC-LR, double aptamer is dissociated from its CS because of its high affinity for MC-LR and leaves the surface of electrode. Subsequently, no Infinity-shaped structure is formed following the introduction of TdT and a strong current signal is observed. The proposed method was employed for specific detection of MC-LR in the range from 60 pM to 1000 nM with a detection limit of 15 pM. The credibility of the approach was confirmed by detection of MC-LR in real samples like serum and tap water samples. This study provides a new aptasensor for detection of MC-LR as well as other toxin analysis.

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.

Enzyme responsive drug delivery systems in cancer treatment

Recent technological approaches in drug delivery have attracted scientist interest for improving therapeutic index of medicines and drug compliance. One of the powerful strategies to control the transportation of drugs is implementation of intelligent stimuli-responsive drug delivery system (DDS). In this regard, tumor tissues with unique characteristics including leaky vasculature and diverse enzyme expression profiles facilitate the development of efficient enzyme-responsive nanoscale delivery systems. Based on the stimuli nature (physical, chemical and biological), these systems can be categorized into three groups according to the nature of trigger initiating the drug release. Enzymes are substantial constituents of the biotechnology toolbox offering promising capabilities and ideal characteristics to accelerate chemical reactions. Nanoparticles which have the ability to trigger their cargo release in the presence of specific enzymes are fabricated implementing fascinating physico-chemical properties of different materials in a nanoscale dimension. In order to reduce the adverse effects of the therapeutic agents, nanocarriers can be utilized and modified with enzyme-labile linkages to provide on-demand enzyme-responsive drug release. In the current review, we give an overview of drug delivery systems which can deliver drugs to the tumor microenvironment and initiate the drug release in response to specific enzymes highly expressed in particular tumor tissues. This strategy offers a versatile platform for intelligent drug release at the site of action.

Design, Synthesis, and Biological Evaluation of New Azole Derivatives as Potent Aromatase Inhibitors with Potential Effects against Breast Cancer

PURPOSE

Some aromatase inhibitors are FDA-approved agents as first-line therapy in the treatment of endocrine-responsive breast cancer. In this study, we aimed to develop new azole derivatives with higher specificity and potency.

METHODS

New aromatase inhibitors were designed by Molecular Operating Environment (MOE) software and synthesized in a one-step SN2 reaction. These compounds were characterized by melting point, 1H- and 13CNMR, elemental analysis and mass spectra. The in vitro and in vivo aromatase inhibition of these compounds was evaluated using the Estrone ELISA assay, and by measuring the inhibition of androstenedione-induced uterine hypertrophy. The selectivity of aromatase inhibition was investigated by the inhibition of ACTH stimulation on the plasma concentrations of aldosterone and cortisol.

RESULTS

Docking simulations showed that four new azole derivatives could efficiently interact with enzyme active sites. The in vitro aromatase-inhibition assay showed that the compounds 1,3,5-tris(imidazol-1- ylmethyl)benzene (3b) and 1,3-Bis(imidazole-1- ylmethyl) benzene (3d) effectively inhibited aromatase, with IC50 values of 0.2 nM and 6.8 nM, respectively; these values were similar to known aromatase inhibitor letrozole (IC50 0.3 nM). The in vivo aromatase-inhibitory potency of compound 3b was similar to letrozole, although compound 3b acted more selectively.

CONCLUSION

This report introduced a new compound that can be considered as a new lead for further investigation to explore more-potent and more-selective aromatase inhibitors.

A rapid and simple ratiometric fluorescent sensor for patulin detection based on a stabilized DNA duplex probe containing less amount of aptamer-involved base pairs

In this study, a sensor is described for determination of patulin by using ratiometric fluorescence measurement and strand displacement strategy. In the presence of patulin, the ratiometric fluorescence response decreases, owing to disassembly of DNA duplex structure and target-mediated release of TAMRA-labeled complementary DNA sequence2 (cDNA2). While, in the absence of target, the fluorescence resonance energy transfer (FRET) phenomenon happens between FAM and TAMRA under excitation at 490 nm, resulting in the enhancement of ratiometric signal. The use of ratiometric fluorescence signal with different signal indicators avoids the problem of environmental interference and improves the sensitivity of the aptasensor. Also, the DNA duplex structure contains minimum aptamer-involved base pair sequence, resulting in further improvement of the aptasensor sensitivity. This sensing platform provided a wide linear range from 15 ng/L to 35 μg/L and a detection limit of 6 ng/L for patulin. The aptasensor was used to determine patulin in spiked apple juice samples and showed satisfactory results.

ABCG2 aptamer selectively delivers doxorubicin to drug-resistant breast cancer cells

Chemotherapy is the most widely used treatment for cancer therapy, but its efficacy is limited by the side effects of non-specific cytotoxic drugs. Ligand-based targeting drug-delivery system is a solution to circumvent this issue. In this study, an ABCG2 aptamer-doxorubicin complex was prepared, and its efficacy in targeted drug delivery tomitoxantrone-resistance breast cancer cell line (MCF7/MX) was evaluated. The formation of aptamer-doxorubicin physical complex was analyzed by fluorometric analysis. The cytotoxicities of doxorubicin and aptamer-doxorubicin complex on MCF7 and MCF7/MX cell lines were evaluated by the MTT assay, and IC50 values were obtained. Cellular uptake of aptamer-doxorubicin complex was assessed by flow cytometry cellular uptake assay. Results: Fluorometric analysis of aptamer-doxorubicin showed 1-1.5 molar ratio of the drug to the aptamer could efficiently quenchDox fluorescence.MTTassay results showed that MCF7/MXcells were more resistant to doxorubicin than MCF7 cells (IC50 : 3.172 +/- 0.536 and 1.456 +/- 0.154 μM, respectively). Flow cytometry andMTTassay results showed that the aptamer-doxorubicin complex could increase the uptake and cytotoxicity of doxorubicin inMCF7/MX cell line in comparisonwith free doxorubicin, while the same treatments had no effect on IC50 of Dox on MCF7 cells. The results proposed that the ABCG2 aptamer-drug complex can be effectively used for specific drug delivery to ABCG2-overexpressing cells.

Correlation of Gankyrin oncoprotein overexpression with histopathological grade in prostate cancer

Prostate cancer is the second most commonly diagnosed cancer among men worldwide. Identifying new prognostic and predictive biomarkers will help stratification of prostate cancer patients for a better treatment. Gankyrin is a novel oncoprotein which regulates cell cycle and protein degradation. Gankyrin overexpression correlated with the malignant phenotypes and promotes the tumorigenicity and metastasis in many cancers. However, there are not any reports on the role of Gankyrin in prostate cancer. Therefore, this study was designed to investigate the expression of Gankyrin in prostate cancer and analyze its correlation with some clinicopathological characteristics. We characterized the expression of gankyrin in fifty five prostate cancer specimens and twenty non-cancerous tissues by immunohistochemical staining and the results were correlated with clinical characteristics and pathological parameters.Results showed that Gankyrin was expressed in 41 of 55 (74%) prostate cancer patients and its expression was significantly higher than corresponding adjacent normal tissues (p<0.001). Gankyrin overexpression was significantly correlated with histopathological tumor grade, Gleason score and tumor differentiation (P=0.002). These findings showed that Gankyrin is mainly overexpressed in high grade prostate tumors so it may have a significant role in prostate cancer progress and it May serve as a useful biomarker for the identification of aggressive prostate cancers.

Targeted imaging of breast cancer cells using two different kinds of aptamers -functionalized nanoparticles

Breast cancer which is the most commonly diagnosed cancer among women; have been known as a serious threat for health and life around the world. So development of an approach for early-stage diagnosis of breast cancer is vital. In this study, we designed a double aptamer-nanoparticle conjugates-based (DANP) complex for specific detection and visualization of MCF-7 cells using Mucin 1 (MUC 1) aptamer-conjugated gold nanoparticles (MUC1 apt - GNPs) and adenosine triphosphate (ATP) aptamer-conjugated CdTe quantum dots (ATP apt-QDs). The ATP apt-QDs was attached onto MUC1 apt - GNPs surface through Van der Waals forces and electrostatic interactions between ATP aptamer and GNPs leading to the formation of DANP complex. Atomic force microscopy asserted DANP complex formation. The imaging process was based on the recognition of MUC1 protein on the surface of MCF-7 cells by MUC1 aptamer and specific internalization of DANP complex into target cells (MCF-7). Existence of abundant amounts of ATP in lysosome led to release of ATP apt-QDs from the MUC1 apt-GNPs surface resulting in strong fluorescence emission. The flow cytometry analysis and fluorescence microscopy confirmed significant internalization of DANP complex into MCF-7 cells (target) in comparison with CHO cells (non-target). Based on the obtained results, the DANP complex possesses high potency for efficient detection and monitoring of breast cancer cells (MCF-7).

High affinity of AS1411 toward copper; its application in a sensitive aptasensor for copper detection

AS1411 is a 26-mer G-rich DNA aptamer which has been broadly employed in the field of targeted drug delivery, due to its capability to bind to nucleolin protein on the surface of cancer cells. In this work, it has been shown for the first time that in addition to nucleolin, AS1411 aptamer could bind to copper ions (Cu²⁺) with high affinity and selectivity, affecting AS1411 usage in drug delivery systems as a targeting agent. In this study, besides the evaluations of the affinity of AS1411 to different ions and the impact of Cu²⁺ on targeted drug delivery employed AS1411 aptamer as a targeting agent, a simple and ultra-sensitive fluorescent aptasensor was fabricated for Cu²⁺ detection through applying AS1411, its complementary strand and magnetic beads coated with streptavidin. Gel Red (GR) was also used as a fluorescent dye. The fabricated aptasensor offered the possibility of condensing samples with different volumes. The detection limit of the sensor was 0.01 μM towards Cu²⁺ in serum samples. The efficacy of this sensor was further confirmed by comparing Cu²⁺ levels in serums of healthy people with patients suffering from Wilson's disease, Alzheimer's disease and Diabetes Mellitus using the proposed sensing platform.

An electrochemical sensing platform based on ladder-shaped DNA structure and label-free aptamer for ultrasensitive detection of ampicillin

Herein, an electrochemical aptasensor is described for detection of ampicillin (Ampi). The sensing strategy is based on the application of a ladder-shaped DNA structure as a multi-layer physical block on the surface of gold electrode. Attributing to the electrostatic repulsion and physical prevention of the ladder-shaped DNA structure, ultrasensitive detection of Ampi was achieved with a detection limit as low as 1 pM. In the presence of Ampi, the ladder-shaped DNA structure is disassembled and detached from the electrode surface. This leads to the high access of [Fe(CN)₆]^3-/4- as a redox indicator to the electrode surface and a strong redox peak. The aptasensor response for Ampi detection was in the linear range from 7 pM to 100 nM with the detection limit of 1 pM. The presented analytical strategy showed its application in detecting Ampi in the spiked milk samples with satisfactory performance. This work can be easily expanded for different targets by alternating the corresponding aptamers.

Targeted delivery of tacrolimus to T cells by pH-responsive aptamer-chitosan- poly(lactic-co-glycolic acid) nanocomplex

Tacrolimus (TAC) acts as an inhibitor of calcineurin, which inhibits the production of interleukin-2. In this study, we aimed to design a targeted delivery platform with poly (lactide-co-glycolide; PLGA) nanoparticles modified with chitosan (CS) and CD8AP17s aptamer (Apt). MOLT-4 cells as CD8 positive and JURKAT cells as CD negative were adopted to investigate the efficacy of the proposed delivery system in vitro. The particle size and Ζ potential of the TAC-PLGA-CS-Apt nanocomplex were 345 nm and 13.7 mV, respectively. Release study showed an efficient TAC release from complex in citrate buffer (pH 5.5). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that TAC-PLGA-CS-Apt nanocomplex was highly selective toward MOLT-4 cells. Complex increased the cellular uptake of TAC in MOLT-4 cells (target) while reducing its cytotoxicity in JURKAT cells (nontarget). Our study showed that complex nanoconjugate could efficiently deliver TAC into MOLT-4 cells as a model of cytotoxic T cell and it could be considered as a potential candidate for TAC delivery.

Corrigendum to "Exosomes derived from TRAIL-engineered mesenchymal stem cells with effective anti-tumor activity in a mouse melanoma model" [International Journal of Pharmaceutics 549 (2018) 218-229]

Exosomes are biological nano-sized vesicles (~30-200 nm in diameter) that are produced by a wide range of cells and play several roles in cell-cell communications. These vesicles contain membrane and cytoplasmic components of producing cells. Mesenchymal stem cells (MSCs) are the ideal producer of exosomes. The secreted vesicles from MSCs are promising biological vehicles for cell-free therapy in regenerative medicine, cancer therapy and targeted delivery of therapeutic agents to the tumor cells. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising member of the TNF family with selective effect on cancerous cells. Recent evidences showed that the membrane TRAIL-armed exosomes possess anti-tumor activity. However, the effect of in vivo administration of TRAIL-armed exosomes has not been reported so far. In the current study, mesenchymal stem cells expressing TRAIL/GFP proteins were prepared with the help of a non-viral vector based on polyethylenimine 25 kDa. Then, exosomes containing TRAIL protein (Exo-TRAIL) were isolated from the supernatant of genetically engineered MSCs and characterized. Antitumor activity of both MSC-derived exosomes and Exo-TRAIL was investigated in vitro and in vivo in three models. The results indicated that the co-injection of both Exo-TRAIL and tumor cells delayed the tumor appearance. Besides, the tumor volume/weight was efficiently decreased in tumor bearing mice. Moreover, it was shown that multi-dose injections of Exo-TRAIL reduced the tumor size while single dose treatment with Exo-TRAIL did not show significant anti-tumor activity. To conclude, these results suggested that MSC-derived Exo-TRAIL has a potential capacity for cancer treatment.

Immunomodulatory properties of MSC-derived exosomes armed with high affinity aptamer toward mylein as a platform for reducing multiple sclerosis clinical score

Mesenchymal stem cell-derived exosome is a safe and effective delivery platform with a potential capacity to exert immunomodulation effect and peripheral tolerance toward auto-reactive cells via bearing regulatory and tolerogenic molecules. Inflammation and neurodegeneration are the clinical manifestation of multiple sclerosis (MS). In order to fight against MS, the efficient choices are the ones, which prevent inflammation and induce remyelination. In this regard, the previously reported LJM-3064 aptamer which showed considerable affinity toward myelin and demonstrated remyelination induction was employed as both targeting ligand and therapeutic agent. Thus, in the current study, the carboxylic acid-functionalized LJM-3064 aptamer was covalently conjugated to the amine groups on the exosome surface through EDC/NHS chemistry. The obtained results showed that the aptamer-exosome bioconjugate could promote the proliferation of oligodendroglia cell line (OLN93) in vitro. Moreover, in vivo administration of the prepared aptamer-exosome bioconjugate in female C57BL/6 mice as a prophylactic measure produced a robust suppression of inflammatory response as well as lowered demyelination lesion region in CNS, resulting in reduced in vivo severity of the disease. The prepared platform employing exosome-based nanomedicine as a novel approach for managing MS would hopefully pave the way to introduce a versatile approach toward an effective clinical reality.