Thermodynamic and structural investigation of the interaction of quaternized 2,3-octakis-[(2-mercaptopyridine)phthalocyaninato] copper (II) sulfate (CuPc) with parallel and hybrid type G-quadruplex.

G-quadruplexes are important drug targets and get attention due to their existence in telomere, ribosomal DNA, promoter regions of some oncogenes, and the untranslated regions of mRNA. Due to the biological roles of G-quadruplexes, investigating of the G-quadruplex-small molecule interaction is essential. The primary motivation for these studies is the possibility of inhibiting cell functions associated with G-quadruplex sequences by binding with small molecules. Targeting the small molecules to desired tissue with the G-quadruplex vehicles is the second important goal of the G-quadruplex-small molecule interaction studies. In the present study, the new peripherally 2-mercaptopyridine octasubstituted copper(II) phthalocyanine and its quaternized derivative (CuPc) were synthesized and characterized by elemental analysis FT-IR, UV-Vis, and mass spectra. The excellent solubility of CuPc in water is essential for its transport in the organism. Because of this feature, its affinity toward G-quadruplex forming aptamers, AS1411, Tel21, and Tel45, was investigated. The UV-Vis spectrophotometric titration data confirmed the prevention of aggregation upon interaction with G-quadruplex, which is very important for biomedical applications. The CD spectroscopic analyses and binding stoichiometry confirmed the "end stacking" model for interaction of AS1411 with CuPc. The interaction of CuPc caused the equilibrium shift from hybrid conformation to antiparallel conformation for Tel21 and Tel45. The isothermal titration calorimeter (ITC) was used for the determination of thermodynamic parameters. The thermodynamic data of the interaction was fitted well with the one-site model. The negative values of Gibbs free energy change confirmed the spontaneous nature of the reactions. Besides, the negative values of enthalpy change and entropy change proved that the nature of processes was "enthalpy driven." The interaction stoichiometry was 2 for AS1411 and Tel21 and 1.5 for Tel45. The binding constants were 1.3(±0.3) × 105 , 3.2(±0.4) × 105 , and 1.1(±0.3) × 105 M-1 , which were at the level of ethidium bromide intercalation binding constant given in the literature. The DNA polymerase stop assay further supported the interaction of CuPc with G-quadruplex DNA. The experimental results confirm that the CuPc has a potential photosensitizer behaviour for photodynamic therapy.

Advancing targeted combination chemotherapy in triple negative breast cancer: nucleolin aptamer-mediated controlled drug release.

BACKGROUND: Triple-negative breast cancer (TNBC) is a recurrent, heterogeneous, and invasive form of breast cancer. The treatment of TNBC patients with paclitaxel and fluorouracil in a sequential manner has shown promising outcomes. However, it is challenging to deliver these chemotherapeutic agents sequentially to TNBC tumors. We aim to explore a precision therapy strategy for TNBC through the sequential delivery of paclitaxel and fluorouracil. METHODS: We developed a dual chemo-loaded aptamer with redox-sensitive caged paclitaxel for rapid release and non-cleavable caged fluorouracil for slow release. The binding affinity to the target protein was validated using Enzyme-linked oligonucleotide assays and Surface plasmon resonance assays. The targeting and internalization abilities into tumors were confirmed using Flow cytometry assays and Confocal microscopy assays. The inhibitory effects on TNBC progression were evaluated by pharmacological studies in vitro and in vivo. RESULTS: Various redox-responsive aptamer-paclitaxel conjugates were synthesized. Among them, AS1411-paclitaxel conjugate with a thioether linker (ASP) exhibited high anti-proliferation ability against TNBC cells, and its targeting ability was further improved through fluorouracil modification. The fluorouracil modified AS1411-paclitaxel conjugate with a thioether linker (FASP) exhibited effective targeting of TNBC cells and significantly improved the inhibitory effects on TNBC progression in vitro and in vivo. CONCLUSIONS: This study successfully developed fluorouracil-modified AS1411-paclitaxel conjugates with a thioether linker for targeted combination chemotherapy in TNBC. These conjugates demonstrated efficient recognition of TNBC cells, enabling targeted delivery and controlled release of paclitaxel and fluorouracil. This approach resulted in synergistic antitumor effects and reduced toxicity in vivo. However, challenges related to stability, immunogenicity, and scalability need to be further investigated for future translational applications.

Improved Tumor Infiltration and Immunomodulation for Tumor Therapy: A Pathway Based on Tetrahedral Framework Nucleic Acids Coupled Bacterial Nanocells.

Growing evidence indicates that the tumor microenvironment (TME) can be combined with other therapeutic modalities, including cytotoxic chemotherapy and targeted therapies, to produce unanticipated results in oncology treatment. Here, we proposed a novel bacterial nanomaterial capable of targeting peritumoral biofilm and modulating TME. It was based on tetrahedral framework nucleic acids (T) that were chemically attached to aptamer AS1411 and 5-fluorouracil (AT5). Additionally, the oral pathogenic bacterium Streptococcus mutans (S.m) was employed as a biocarrier for synergetic biofilm targeting and immunomodulation. In this article, the effect of AT5-coupled S.m-derived nanocells (S.m-AT5) was investigated in vitro and in vivo. Due to bacteria aggregation in the tumor-specific biofilm, these nanocells released greater medication concentrations. Furthermore, they exerted an immunomodulatory effect by stimulating the maturation of dendritic cells (DCs) and regulation of T cells. This chemo-immunostimulation combination has a powerful antitumor impact. It may also be an advanced approach for boosting the survival rate of cancer patients.

Inhibition of tumor-specific angiogenesis by AS1411 aptamer functionalized Withaferin A loaded PEGylated nanoliposomes by targeting nucleolin.

Angiogenesis is a vital process for tumor growth and metastasis. Inhibition of angiogenesis is a promising strategy in cancer treatment. In this study, we analyzed the anti-angiogenic activity of AS1411 functionalized Withaferin A encapsulated PEGylated nanoliposomes (ALW) using both in vitro and in vivo models. AS1411 aptamer functionalized nanoliposomes are an efficient drug delivery system for carrying chemotherapeutic agents to target cancer cells, and Withaferin A (WA) is a steroidal lactone known for potent anti-angiogenic activity. ALW showed significant inhibition in the migration and tube formation of endothelial cells, which are critical events in angiogenesis. In vivo angiogenesis study using ALW showed remarkable inhibition of tumor-directed capillary formation by altered serum cytokines, VEGF, GM-CSF, and NO levels. ALW treatment downregulated the gene expression of Matrix metalloproteinase (MMP)-2, MMP-9, VEGF, NF-kB and upregulated the expression of tissue inhibitor of metalloproteinase (TIMP)-1. Our results demonstrate that ALW inhibits tumor-specific angiogenesis by gene expression of NF-κB, VEGF, MMP-2, and MMP-9. The present study shows that using ALW can offer an attractive strategy for inhibiting tumor angiogenesis.

A nucleolin-activated polyvalent aptamer nanoprobe for the detection of cancer cells.

Sensitive detection of cancer cells plays a critical role in early cancer diagnosis. Nucleolin, overexpressed on the surface of cancer cells, is regarded as a candidate biomarker for cancer diagnosis. Thus, cancer cells can be detected through the detection of membrane nucleolin. Herein, we designed a nucleolin-activated polyvalent aptamer nanoprobe (PAN) to detect cancer cells. In brief, a long single-stranded DNA with many repeated sequences was synthesized through rolling circle amplification (RCA). Then the RCA product acted as a scaffold chain to combine with multiple AS1411 sequences, which was doubly modified with fluorophore and quenching group, respectively. The fluorescence of PAN was initially quenched. Upon binding to target protein, the conformation of PAN changed, leading to the recovery of fluorescence. The fluorescence signal of cancer cells treated with PAN was much brighter compared with that of monovalent aptamer nanoprobes (MAN) at the same concentration. Furthermore, the binding affinity of PAN to B16 cells was proved to be 30 times higher than that of MAN by calculating the dissociation constants. The results indicated that PAN could specifically detect target cells, and this design concept has potential to become promising in cancer diagnosis.

NIR/pH-triggered aptamer-functionalized DNA origami nanovehicle for imaging-guided chemo-phototherapy.

Targeted chemo-phototherapy has received widespread attention in cancer treatment for its advantages in reducing the side effects of chemotherapeutics and improving therapeutic effects. However, safe and efficient targeted-delivery of therapeutic agents remains a major obstacle. Herein, we successfully constructed an AS1411-functionalized triangle DNA origami (TOA) to codeliver chemotherapeutic drug (doxorubicin, DOX) and a photosensitizer (indocyanine green, ICG), denoted as TOADI (DOX/ICG-loaded TOA), for targeted synergistic chemo-phototherapy. In vitro studies show that AS1411 as an aptamer of nucleolin efficiently enhances the nanocarrier's endocytosis more than 3 times by tumor cells highly expressing nucleolin. Subsequently, TOADI controllably releases the DOX into the nucleus through the photothermal effect of ICG triggered by near-infrared (NIR) laser irradiation, and the acidic environment of lysosomes/endosomes facilitates the release. The downregulated Bcl-2 and upregulated Bax, Cyt c, and cleaved caspase-3 indicate that the synergistic chemo-phototherapeutic effect of TOADI induces the apoptosis of 4T1 cells, causing ~ 80% cell death. In 4T1 tumor-bearing mice, TOADI exhibits 2.5-fold targeted accumulation in tumor region than TODI without AS1411, and 4-fold higher than free ICG, demonstrating its excellent tumor targeting ability in vivo. With the synergetic treatment of DOX and ICG, TOADI shows a significant therapeutic effect of ~ 90% inhibition of tumor growth with negligible systemic toxicity. In addition, TOADI presents outstanding superiority in fluorescence and photothermal imaging. Taken together, this multifunctional DNA origami-based nanosystem with the advantages of specific tumor targeting and controllable drug release provides a new strategy for enhanced cancer therapy.

Aptamer functionalized nucleic acid nano drug for targeted synergistic therapy for colon cancer.

Due to its complicated pathophysiology, propensity for metastasis, and poor prognosis, colon cancer is challenging to treat and must be managed with a combination of therapy. Using rolling circle transcription (RCT), this work created a nanosponge therapeutic medication system (AS1411@antimiR-21@Dox). Using the AS1411 aptamer, this approach accomplished targeted delivery to cancer cells. Furthermore, analysis of cell viability, cell apoptosis, cell cycle arrest, reactive oxygen species (ROS) content, and mitochondrial membrane potential (MMP) levels revealed that functional nucleic acid nanosponge drug (FND) can kill cancer cells. Moreover, transcriptomics uncovered a putative mechanism for the FND anti-tumor effect. These pathways, which included mitotic metaphase and anaphase as well as the SMAC-mediated dissociation of the IAP: caspase complexes, were principally linked to the cell cycle and cell death. In conclusion, by triggering cell cycle arrest and apoptosis, the nano-synergistic therapeutic system allowed for the intelligent and effective targeted administration of RNA and chemotherapeutic medicines for colon cancer treatment. The system allowed for payload efficiency while being customizable, targeted, reliable, stable, and affordable.

Insights on the molecular mechanisms of cytotoxicity induced by AS1411 linked to folate-functionalized DNA nanocages in cancer cells.

Self-assembled multivalent DNA nanocages are an emerging class of molecules useful for biomedicine applications. Here, we investigated the molecular mechanisms of cytotoxicity induced by AS1411 free aptamer, AS1411-linked nanocages (Apt-NCs) and nanocages harboring both folate and AS1411 functionalization (Fol-Apt-NCs) in HeLa and MDA-MB-231 cancer cell lines. The three treatments showed different cytotoxic efficacy and Fol-Apt-NCs resulted the most effective in inhibiting cell proliferation and inducing apoptotic pathways and ROS activation in both HeLa and MDA-MB-231 cells. RNA-seq analysis allowed to identify biological functions and genes altered by the various treatments, depending on the AS1411 route of intracellular entry, highlighting the different behavior of the two cancer cell lines. Notably, Fol-Apt-NCs altered the expression of a subset of genes associated to cancer chemoresistance in MDA-MB-231, but not in HeLa cells, and this may explain the increased chemosensitivity to drugs delivered through DNA nanocages of the triple-negative breast cancer cells.

Targeted poly(L-glutamic acid)-based hybrid peptosomes co-loaded with doxorubicin and USPIONs as a theranostic platform for metastatic breast cancer.

Peptosomes, as a vesicular polypeptide-based system and a versatile carrier for co-delivery of hydrophilic and hydrophobic materials, provide great delivery opportunities due to the intrinsic biocompatibility and biodegradability of the polypeptides backbone. In the current study, a novel poly(L-glutamic acid)-block-polylactic acid di-block copolymer (PGA-PLA) was synthesized in two steps. Firstly, γ-benzyl L-glutamate-N-carboxy anhydride (BLG-NCA) and 3,6-dimethyl-1,4-dioxane-2,5-dione were polymerized using N-hexylamine and benzyl alcohol as initiators to produce poly(γ-benzyl L-glutamate (PBLG) and polylactic acid. Then, PBLG was deprotected to produce PGA. Secondly, PGA was conjugated to the benzyl-PLGA to fabricate PGA-PLA diblock copolymer. The synthesized diblock copolymer was used for the encapsulation of doxorubicin, as hydrophilic anticancer and ultra-small superparamagnetic iron oxide nanoparticles (USPIONs) as hydrophobic contrast agent within aqueous core and bilayer of vesicular peptosome, respectively via double emulsion method. The prepared peptosomes (Pep@USPIONs-DOX) controlled the release of DOX (<15 % of the encapsulated DOX release up to 240 h of incubation at the physiological conditions) while increasing the stability and solubility of the hydrophobic USPIONs. Then, AS1411 DNA aptamer was decorated on the surface of the PGA-PLA peptosomes (Apt-Pep@USPIONs-DOX). The prepared targeted and non-targeted platforms showed spherical morphology with hydrodynamic sizes of 265 ± 52 and 229 ± 44 nm respectively. In vitro cellular cytotoxicity and cellular uptake were studied in nucleolin positive (4T1) and nucleolin negative (CHO) cell lines. Cellular uptake of the targeted formulation was greater than that of non-targeted peptosome, while cellular internalization of these peptosomes was identical in CHO cells. Moreover, targeted peptosomes showed greater toxicity than non-targeted peptosome in 4T1 cell line. The prepared theranostic targeted peptosomes demonstrated improved capability in terms of survival rate, biodistribution, tumor suppression efficiency, and MR imaging in the 4T1 tumor-bearing mice.

AS1411aptamer conjugated liposomes for targeted delivery of arsenic trioxide in mouse xenograft model of melanoma cancer.

Development of AS1411aptamer-conjugated liposomes for targeted delivery of arsenic trioxide is the primary goal of this study. AS1411aptamer was used as ligand to target nucleolin, which is highly expressed on the surface of melanoma cancer cells. The targeted liposomes were constructed by the thin film method, and arsenic trioxide was loaded as cobalt (II) hydrogen arsenite (CHA) to increase the loading efficiency and stability of the liposomes. The liposomal structure was characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and field emission scanning electron microscopy (FESEM). In addition, particle sizes and zeta potential of the CHA-loaded liposomes (CHAL) and aptamer-functionalized CHA-loaded liposomes (AP-CHAL) were determined. In vitro cytotoxicity of CHAL and AP-CHAL were evaluated using MTT assay in murine melanoma (B16) and mouse embryonic fibroblast (MEF) cell lines. The encapsulation efficiency of CHAL and AP-CHAL was reported as 60.2 ± 6.5% and 58.7 ± 4.2%, respectively. In vivo antitumor activity of CHAL and AP-CHAL in the B16 tumor-xenograft mouse model was dramatically observed. All mice of both groups survived until the end of treatment and showed body weight gain. The tumor protrusion completely disappeared in 50% of the mice in these groups. Furthermore, histopathology studies demonstrated that CHAL and AP-CHAL did not induce significant toxicity in healthy mice tissues. However, unlike the CHAL group, which showed an initial increase in tumor volume, a specific antitumor effect was observed in the AP-CHAL group from the beginning of treatment. The results showed that AP-CHAL can be used as an effective drug delivery system with high potential in the treatment of solid tumors.

An insight into fluorescence and magnetic resonance bioimaging using a multifunctional polyethyleneimine-passivated gadocarbon dots nanoconstruct assembled with AS1411.

A nanoassembly of PEI-passivated Gd@CDs, a type of aptamer, is presented which was designed and characterized in order to target specific cancer cells based on their recognition of the receptor nucleolin (NCL), which is overexpressed on the cell membrane of breast cancer cells for fluorescence and magnetic resonance imaging and treatment. Using hydrothermal methods, Gd-doped nanostructures were synthesized, then modified by a two-step chemical procedure for subsequent applications: the passivating of Gd@CDs with branched polyethyleneimine (PEI) (to form Gd@CDs-PEI1 and Gd@CDs-PEI2), and using AS1411 aptamer (AS) as a DNA-targeted molecule (to generate AS/Gd@CDs-PEI1 and AS/Gd@CDs-PEI2). Consequently, these nanoassemblies were constructed as a result of electrostatic interactions between cationic Gd@CDs-passivated PEI and AS aptamers, offering efficient multimodal targeting nanoassemblies for cancer cell detection. It has been demonstrated through in vitro studies that both types of AS-conjugated nanoassemblies are highly biocompatible, have high cellular uptake efficiency (equivalent concentration of AS: 0.25 µΜ), and enable targeted fluorescence imaging in nucleolin-positive MCF7 and MDA-MB-231 cancer cells compared to MCF10-A normal cells. Importantly, the as-prepared Gd@CDs, Gd@CDs-PEI1, and Gd@CDs-PEI2 exhibit higher longitudinal relaxivity values (r1) compared with the commercial Gd-DTPA, equal to 5.212, 7.488, and 5.667 mM-1s-1, respectively. Accordingly, it is concluded that the prepared nanoassemblies have the potential to become excellent candidates for cancer targeting and fluorescence/MR imaging agents, which can be applied to cancer imaging and personalized nanomedicine.

Dual-targeted delivery system using hollow silica nanoparticles with H+-triggered bubble generating characteristic coated with hyaluronic acid and AS1411 for cancer therapy.

OBJECTIVE: Herein, a dual-targeting delivery system using mesoporous silica nanoparticles with hollow structures (HMSNs) was developed for the specific delivery of epirubicin (EPI) to cancer cells and introducing a H+-triggered bubble generating nanosystem (BGNS). HMSNs containing EPI are covered by hyaluronic acid (HA) shell and AS1411 aptamer to create the BGNS-EPI-HA-Apt complex, which is highly selective against CD44 marker and nucleolin overexpressed on the surface of tumor cells. METHODS: MTT assay compared the cytotoxicity of different treatments in CHO (Chinese hamster ovary) cells as well as 4T1 (murine mammary carcinoma) and MCF-7 (human breast adenocarcinoma) cells. The internalization of Epi was assessed by flow cytometry along with fluorescence imaging. In vivo studies were conducted on BALB/c mice bearing a tumor from 4T1 cell line where monitoring included measuring tumor volume, mouse weight changes over time alongside mortality rate; accumulation levels for Epi within organs were also measured during this process. RESULTS: The collected data illustrated that BGNS-EPI-HA-Apt complex controlled the release of EPI in a sustained method. Afterward, receptor-mediated internalization via nucleolin and CD44 was verified in 4T1 and MCF-7 cells using fluorescence microscopy assay and flow cytometry analysis. The results of tumor inhibitory effect study exhibited that BGNS-EPI-HA-Apt complex decreased off-target effect and improved on-target effects because of its targeting ability. CONCLUSION: The data acquired substantiates that HA-surface modified HMSNs functionalized with aptamers possess significant potential as a focused platform for efficient transportation of anticancer agents to neoplastic tissues.

Parahydrogen-Induced Polarization of a Labeled, Cancer-Targeting DNA Aptamer.

Enhancing NMR signals of biomacromolecules by hyperpolarization offers exciting opportunities for diagnostic applications. However, their hyperpolarization via parahydrogen remains challenging as specific catalytic interactions are required, which are difficult to tune due to the large size of the biomolecule and its insolubility in organic solvents. Herein, we show the unprecedented hyperpolarization of the cancer-targeting DNA aptamer AS1411. By screening different molecular motifs for an unsaturated label in nucleosides and in DNA oligomers, we were able to identify structural prerequisites for the hyperpolarization of AS1411. Finally, adjusting the polarity of AS1411 by complexing the DNA backbone with amino polyethylene glycol chains allowed the hydrogenation of the label with parahydrogen while the DNA structure remains stable to maintain its biological function. Our results are expected to advance hyperpolarized molecular imaging technology for disease detection in the future.

Implication of extrinsic and intrinsic apoptotic pathways in the targeted therapy of hepatocellular carcinoma using aptamer-labeled viramidine nanoparticles.

Hepatocellular carcinoma (HCC) is a global health problem with regional differences in epidemiological statistics. Co-assembling the drug nanoparticles and targeting moieties could improve the therapeutic delivery of anti-cancer drugs. In this attempt, we tracked the extrinsic and intrinsic apoptotic pathways in HCC cells using viramidine (VRM)-loaded aptamer (APT) nanoparticles. In these NPs, both APT and VRM act as targeted ligands/drugs to HCC cells. The NPs were characterized using TEM, ESI-MS, FTIR, and 1H NMR. The results showed uniform particles with round and smooth shapes on the nano-scale. SRB-based cytotoxicity was performed and IC50 values were measured for HCC versus normal cells upon the proposed treatments. The flow cytometry technique was applied to determine apoptosis, then confirmed using genetic and protein analyses. In addition, nitric oxide (NO) and its enzyme (iNOS) were analyzed to examine the effect of reactive nitrogen species (RNS) on apoptosis induction. The present findings indicated that Huh-7 cells were more sensitive to APT-VRM NPs than HepG2 cells, recording the lowest IC50 values (11.23 ± 0.23 µM and 16.69 ± 1.12 µM), as well as the highest significant increase in the apoptotic cells (61.5% and 42%), respectively. Intriguingely, normal BHK-21 cells recorded undetectable IC50 values in the applied NPs, confirming their targeted delivery ability. The genetic expression and protein levels of c-FLIP, Bcl-2, and TNF-α were down-regulated, while FADD, caspase 8, caspase 3, caspase 9, and Bax were up-regulated upon treatment with APT-VRM NPs. The prepared VRM NPs labeled with APT could significantly elevate NO via activation of iNOS. In conclusion, APT-VRM NPs bioconjugate interferes with HCC cells through NO-mediated extrinsic and intrinsic apoptosis.

Amino-modified-silica-coated gadolinium-copper nanoclusters, conjugated to AS1411 aptamer and radiolabeled with technetium-99 m as a novel multimodal imaging agent.

Hybridimagingtechnology has the potential to provide reliable imagingand accurate detection of cancer cells by combining the advantages and overcoming the shortages of various clinical imaging tools. Nanomaterials with unique targeting properties and their small size have improved biomedical imaging. Indeed, their small size determines local contrast agent concentrations in tumors by enhanced permeability and retention (EPR) effect. In this work, amino-modified silica-coated Gadolinium-Copper Nanoclusters were fabricated and conjugated to AS1411 aptamer (Apt-ASGCuNCs) and radiolabeled with technetium-99 m (99mTc) for in vivo fluorescence imaging, magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT). The synthesized nanoconjugate was fully characterized by transmission electron microscopy (TEM), element mapping, fluorescence spectroscopy, and Fourier-transform infrared spectroscopy. Moreover, XTT assay, and apoptosis and necrosis methods were applied to study toxicity. Radiochemical yield was calculated 93% that revealed a great potential for complex formation between Apt-ASGCuNCs and 99mTcO4-. Also, good stability of 99mTc-Apt-ASGCuNCs was found in the human serum up to 4 h. Both Apt-ASGCuNCs and 99mTc-Apt-ASGCuNCs indicated a considerable tumor-targeting in in vivo fluorescence imaging, MRI and SPECT with 4T1 tumor-bearing BALB/c mice. The biodistribution results showed no undesirable accumulation of 99mTc-Apt-ASGCuNCs in the liver, and spleen as it circulated freely in the blood pool. Meanwhile, 99mTc-Apt-ASGCuNCs were removed from the body through the renal clearance system, making it more convenient for future multimodality imaging applications.

Progress in cancer drug delivery based on AS1411 oriented nanomaterials.

Targeted cancer therapy has become one of the most important medical methods because of the spreading and metastatic nature of cancer. Based on the introduction of AS1411 and its four-chain structure, this paper reviews the research progress in cancer detection and drug delivery systems by modifying AS1411 aptamers based on graphene, mesoporous silica, silver and gold. The application of AS1411 in cancer treatment and drug delivery and the use of AS1411 as a targeting agent for the detection of cancer markers such as nucleoli were summarized from three aspects of active targeting, passive targeting and targeted nucleic acid apharmers. Although AS1411 has been withdrawn from clinical trials, the research surrounding its structural optimization is still very popular. Further progress has been made in the modification of nanoparticles loaded with TCM extracts by AS1411.

Novel and efficient method for loading aptamer-conjugated liposomes with arsenic trioxide for targeting cancer cells.

Although the therapeutic effect of liposomal arsenic trioxide arsenic trioxide (ATO) in the treatment of solid tumours has been confirmed, its dose-limiting loading is a challenging issue. To solve the problems in the preparation of liposomal ATO, different loading strategies were evaluated and compared. In addition, liposomes decorated with anti-nucleolin aptamers were developed as a novel formulation for targeted delivery with high loading efficiency and sustained releasing property in order to treat solid tumours. The liposomes were prepared by a thin-film method exploiting the passive loading strategy of Co(II) hydrogen arsenite (CHA). The structural characteristics of the liposomes were also investigated by Fourier transform infra-red spectroscopy (FT-IR), dynamic light scattering (DLS), zeta potentiometry, field emission scanning electron microscopy (FESEM), and Energy Dispersive X-ray Diffraction (EDX) techniques. To evaluate the potential cytotoxicity of this liposomal drug vehicle in vitro, MTT assay was performed on HT-29 cancer cell line. The results showed that the synthesised liposomes loaded with CHA exhibited high entrapment efficiency (77%). MTT assays showed a significant difference between the percentage of viable cells when HT -29 cells were treated with free ATO and liposomal formulation which can be corresponded to the sustained release of the drug from the liposomes. The results of this study may lead to a promising strategy for the effective treatment of solid tumours.

PEGylated solid lipid nanoparticles functionalized by aptamer for targeted delivery of docetaxel in mice bearing C26 tumor.

OBJECTIVE: Colorectal cancer is one of the most deadly cancers in the world. Docetaxel (DTX) is a potentially important chemotherapeutic agent for the treatment of cancer. Many studies have attempted to improve its bioavailability and efficiency using different nanoparticulate drug delivery systems. SIGNIFICANCE: In the current study, PEGylated solid lipid nanoparticles (SLNs) containing DTX were prepared and modified with AS1411 anti-nucleolin aptamers to target nucleoin receptors on colorectal cancer cells. METHODS: Nanoparticles were characterized and the morphology was evaluated. In vitro studies were investigated on murine colon carcinoma (C26) and Chinese hamster ovary (CHO) cell lines. Then in vivo antitumor efficacy and survival analysis were evaluated in mice bearing the C26 tumor model. RESULTS: Results showed 135-140 nm particle size and about 78% DTX entrapment efficiency for actively targeted samples. PEGylated and aptamer-targeted SLNs containing DTX had the lowest IC50 (0.28 and 0.11 nM for 3 and 6 h incubation respectively) and higher cellular uptake values in the C26 cell line. Also in vivo results demonstrated that PEGylated and aptamer-targeted SLNs containing Docetaxel (Apt-PEG-SLN-DTX) improved antitumor activity and inhibited tumor growth in C26 tumor-bearing mice. CONCLUSION: These results suggested that PEGylated and aptamer-targeted SLNs containing DTX exhibited efficient characteristics in tumor inhibitory against murine C26 carcinoma model.

A molecular hybrid comprising AS1411 and PDGF-BB aptamer, cholesterol, and doxorubicin for inhibiting proliferation of SW480 cells.

Cancer treatment commonly relies on chemotherapy. This treatment faces many challenges, including treatment specificity and undesired side effects. To address these, a Dox-loaded Chol-aptamer molecular hybrid (Dox-CAH) was developed. This multivalent interaction system combines the key function of each integrated species: doxorubicin, cholesterol, and two aptamers binding to nucleolin and platelet-derived growth factor BB (PDGF-BB). The study has four stages: preparation of CAH via oligonucleotide hybridization, intercalation of doxorubicin into CAH, verification of CAH binding on SW480 by fluorescence microscopy and flow cytometry, and investigation of effect of Dox-CAH on SW480 proliferation. CAH was successfully prepared, as confirmed by electrophoresis. Flow cytometry and fluorescence microscopy demonstrated CAH binding to SW480, due to the presence of the AS1411 aptamer. This molecular hybrid exhibited specific binding because it did not bind to CCD 841 CoN. CAH binding to PDGF-BB compromises its function, as shown by enzyme-linked immunosorbent assay (ELISA) and cell assay. The DNA duplex in this molecular hybrid reduces the cytotoxicity of the Dox-CAH. Binding and the reduction of Dox-CAH toxicity may improve treatment specificity and minimize side effects. Dox-CAH is a model for more effective anticancer therapy, allowing incorporation of chemotherapeutic drugs and recognition elements.

Nanoaggregate-forming lipid-conjugated AS1411 aptamer as a promising tumor-targeted delivery system of anticancer agents in vitro.

Nanoparticles offer targeted delivery of drugs with minimal toxicity to surrounding healthy tissue and have great potential in the management of human papillomavirus (HPV)-related diseases. We synthesized lipid-modified AS1411 aptamers capable of forming nanoaggregates in solution containing Mg2+. The nanoaggregates presented suitable properties for pharmaceutical applications such as small size (100 nm), negative charge, and drug release. The nanoaggregates were loaded with acridine orange derivative C8 for its specific delivery into cervical cancer cell lines and HPV-positive tissue biopsies. This improved inhibition of HeLa proliferation and cell uptake without significantly affecting healthy cells. Finally, the nanoaggregates were incorporated in a gel formulation with promising tissue retention properties aiming at developing a local delivery strategy of the nanoaggregates in the female genital tract. Collectively, these findings suggest that the nanoformulation protocol has great potential for the delivery of both anticancer and antiviral agents, becoming a novel modality for cervical cancer management.