Ladder-like targeted and gated doxorubicin delivery using bivalent aptamer in vitro and in vivo

Aptamers capable of simultaneously identifying multiple targets and corresponding applications in medical diagnosis-A review

Aptamers, a unique class of nucleic acid sequences recognized for their specific binding capabilities, have found widespread application in biomedical field. While traditional aptamers are typically designed to target a single molecule recognition, recent attention has been directed towards multifunctional aptamers capable of simultaneously identifying multiple targets. In this review, the latest advancements in multifunctional aptamers and their applications in medical diagnosis are presented for the first time. This review focuses on the following essential aspects, including methods employed for developing multifunctional aptamers, detailed characteristics of these aptamers, practical applications across diverse diagnostic scenarios, and in-depth discussions on critical aspects of their design and utility. To conclude, future perspectives are provided to drive further development and broader application of multifunctional aptamers in the biomedical domain.

Aptamer-controlled stimuli-responsive drug release

Aptamers have been widely researched and applied in nanomedicine due to their programmable, activatable, and switchable properties. However, there are few reviews on aptamer-controlled stimuli-responsive drug delivery. This article highlights the mechanisms and advantages of aptamers in the construction of stimuli-responsive drug delivery systems. We summarize the assembly/reconfiguration mechanisms of aptamers in controlled release systems. The assembly and drug release strategies of drug delivery systems are illustrated. Specifically, we focus on the binding mechanisms to the target and the factors that induce/inhibit the binding to the stimuli, such as strand, pH, light, and temperature. The applications of aptamer-based stimuli-responsive drug release are elaborated. The challenges are discussed, and the future directions are proposed.

Targeted delivery of elesclomol using a magnetic mesoporous platform improves prostate cancer treatment both in vitro and in vivo

BACKGROUND

To improve the anticancer properties of elesclomol (ELC), targeted theranostic nanoparticles (NPs; APT-PEG-Au-MMNPs@ELC) were designed to increase the selectivity of the drug delivery system (DDS).

MATERIALS AND METHODS

ELC was synthesized and entrapped in the open porous structure of magnetic mesoporous silica nanoparticles (MMNPs). The pore entrance of MMNPs was then blocked using gold gatekeepers. Finally, the external surfaces of the particles were grafted with functional polyethylene glycol (PEG) and EpCAM aptamer to generate biocompatible and targeted NPs. In the next step, the physicochemical properties of prepared NPs were fully evaluated and their anticancer potential was evaluated both in vitro and in vivo.

RESULTS

The targeted NPs were successfully synthesized with a final size diameter of 81.13 ± 7.41 nm. The results indicated a pH-dependent release pattern, which sustained for 72 h despite an initial rapid release. Upon exposure to APT-PEG-Au-MMNPs@ELC, higher cytotoxicity was observed in human prostate cancer cells (PC-3) as compared with control Chinese hamster ovary (CHO) cells, indicating higher specificity of targeted NPs against EpCAM-positive cancerous cells. Moreover, APT-PEG-Au-MMNPs@ELC could induce apoptosis in PC-3 cells. In vivo results on a PC-3 xenograft tumor model demonstrated that targeted NPs could significantly inhibit tumor growth and diminish severe side effects of ELC, compared to the free drug.

CONCLUSION

Collectively, APT-PEG-Au-MMNPs@ELC could be considered a promising theranostic platform for the targeted delivery of ELC to improve its therapeutic effects in prostate cancer.

Aptamer/doxorubicin-conjugated nanoparticles target membranous CEMIP2 in colorectal cancer

The objectives were to identify the functional domains of a potential oncoprotein, cell migration inducing hyaluronidase 2 (CEMIP2), evaluate its expression levels and roles in colorectal cancer (CRC), and develop an aptamer-based nanoparticle for targeted therapy. Data mining on TCGA identified that CEMIP2 might play oncogenic roles in CRC. In a local cohort, CEMIP2 mRNA levels significantly stepwise increase in CRC patients with higher stages, and high CEMIP2 confers worse disease-free survival. In addition, CEMIP2 mRNA levels significantly correlated to hyaluronan levels in sera from CRC patients. Deletion mapping identified that CEMIP2 containing G8 and PANDER-like domains preserved hyaluronidase activity and oncogenic roles, including cell proliferation, anchorage-independent cell growth, cell migration and invasion, and human umbilical vein endothelial cell (HUVEC) tube formation in CRC-derived cells. A customized monoclonal mouse anti-human CEMIP2 antibody probing the PANDER-like domain (anti-289307) counteracted CEMIP2-mediated carcinogenesis in vitro. Cell-SELEX pinpointed an aptamer, aptCEMIP2(101), specifically interacted with the full-length CEMIP2, potentially involving its 3D structure. Treatments with aptCEMIP2(101) significantly reduced CEMIP2-mediated tumorigenesis in vitro. Mesoporous silica nanoparticles (MSN) carrying atpCEMIP2(101) and Dox were fabricated. Dox@MSN, MSN-aptCEMIP2(101), and Dox@MSN-aptCEMIP2(101) significantly suppressed tumorigenesis in vitro compared to the Mock, while Dox@MSN-aptCEMIP2(101) showed substantially higher effects compared to Dox@MSN and MSN-aptCEMIP2(101) in CRC-derived cells. Our study identified a novel oncogene and developed an effective aptamer-based targeted therapeutic strategy.

DNA-Based Nanomaterials as Drug Delivery Platforms for Increasing the Effect of Drugs in Tumors

DNA nanotechnology has significantly advanced and might be used in biomedical applications, drug delivery, and cancer treatment during the past few decades. DNA nanomaterials are widely used in biomedical research involving biosensing, bioimaging, and drug delivery since they are remarkably addressable and biocompatible. Gradually, modified nucleic acids have begun to be employed to construct multifunctional DNA nanostructures with a variety of architectural designs. Aptamers are single-stranded nucleic acids (both DNAs and RNAs) capable of self-pairing to acquire secondary structure and of specifically binding with the target. Diagnosis and tumor therapy are prospective fields in which aptamers can be applied. Many DNA nanomaterials with three-dimensional structures have been studied as drug delivery systems for different anticancer medications or gene therapy agents. Different chemical alterations can be employed to construct a wide range of modified DNA nanostructures. Chemically altered DNA-based nanomaterials are useful for drug delivery because of their improved stability and inclusion of functional groups. In this work, the most common oligonucleotide nanomaterials were reviewed as modern drug delivery systems in tumor cells.

Nucleolin recognizing silica nanoparticles inhibit cell proliferation by activating the Bax/Bcl-2/caspase-3 signalling pathway to induce apoptosis in liver cancer

Multifunctional nanocarrier platforms have shown great potential for the diagnosis and treatment of liver cancer. Here, a novel nucleolin-responsive nanoparticle platform was constructed for the concurrent detection of nucleolin and treatment of liver cancer. The incorporation of AS1411 aptamer, icaritin (ICT) and FITC into mesoporous silica nanoparticles, labelled as Atp-MSN (ICT@FITC) NPs, was the key to offer functionalities. The specific combination of the target nucleolin and AS1411 aptamer caused AS1411 to separate from mesoporous silica nanoparticles surface, allowing FITC and ICT to be released. Subsequently, nucleolin could be detected by monitoring the fluorescence intensity. In addition, Atp-MSN (ICT@FITC) NPs can not only inhibit cell proliferation but also improve the level of ROS while activating the Bax/Bcl-2/caspase-3 signalling pathway to induce apoptosis in vitro and in vivo. Moreover, our results demonstrated that Atp-MSN (ICT@FITC) NPs had low toxicity and could induce CD3⁺ T-cell infiltration. As a result, Atp-MSN (ICT@FITC) NPs may provide a reliable and secure platform for the simultaneous identification and treatment of liver cancer.

PNA-ATP aptamer-capped doxorubicin-loaded silica nanoparticles for targeted cancer therapy

Nanomaterial-based drug delivery has opened new horizons in cancer therapy. This study aimed to investigate the in vitro and in vivo anti-cancer effects of a hyaluronic acid (HA)-targeted nanocarrier based on hollow silica nanoparticles (HSNPs), gated with peptide nucleic acid (PNA) and ATP aptamer (ATP_Apt) and loaded with doxorubicin (DOX). After formulation of a smart drug delivery nanosystem (HSNPs/DOX/ATP_Apt/PNA/HA), drug release, cytotoxicity, uptake, and in vivo anti-tumor properties were studied. Drug release test showed the controlled release of encapsulated DOX in response to ATP content. MTT and flow cytometry indicated that HA could improve both cytotoxicity and cellular uptake of the formulation. Moreover, HA-targeted formulation enhanced both the survival rate and tumor inhibition in the tumor-bearing mice compared with free DOX (P < 0.05). Our findings confirmed that HA-targeted nanoformulation, gated with PNA/aptamer and loaded with DOX can provide a novel therapeutic platform with great potential for cancer therapy.

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.