Identification of a Nucleoporin358-Specific RNA Aptamer for Use as a Nucleus-Targeting Liposomal Delivery System

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.

Axial pharmaceutical properties of liposome in cancer therapy: Recent advances and perspectives

Evaluation of axial properties including preparation, surface functionalization, and pharmacokinetics for delivery of pharmacologically active molecules and genes lead to pharmaceutical development of liposome in cancer therapy. Here, analysis of effects of the axial properties of liposome based on cancer treatment modalities as individually and coherently is vital and shows deserving further investigation for the future. In this review, recent progress in the analysis of preparation approaches, optimizing pharmacokinetic parameters, functionalization and targeting improvement and modulation of biological factors and components resulting in a better function of liposome in cancer for drug/gene delivery and immunotherapy are discussed. Here, recent developments on liposome with vaccines and immunoadjuvant carriers, and antigen-carrier system to cancer immunotherapy are introduced.

Nucleic Acid Aptamers as a Potential Nucleus Targeted Drug Delivery System

BACKGROUND

Nucleus targeted drug delivery provides several opportunities for the treatment of fatal diseases such as cancer. However, the complex nucleocytoplasmic barriers pose significant challenges for delivering a drug directly and efficiently into the nucleus. Aptamers representing singlestranded DNA and RNA qualify as next-generation highly advanced and personalized medicinal agents that successfully inhibit the expression of certain proteins; possess extraordinary gene-expression for manoeuvring the diseased cell's fate with negligible toxicity. In addition, the precisely directed aptamers to the site of action present a tremendous potential to reach the nucleus by escaping the ensuing barriers to exhibit a better drug activity and gene expression.

OBJECTIVE

This review epigrammatically highlights the significance of targeted drug delivery and presents a comprehensive description of the principal barriers faced by the nucleus targeted drug delivery paradigm and ensuing complexities thereof. Eventually, the progress of nucleus targeting with nucleic acid aptamers and success achieved so far have also been reviewed.

METHODS

Systematic literature search was conducted of research published to date in the field of nucleic acid aptamers.

CONCLUSION

The review specifically points out the contribution of individual aptamers as the nucleustargeting agent rather than aptamers in conjugated form.

Cabazitaxel liposomes with aptamer modification enhance tumor‑targeting efficacy in nude mice

The present study investigated the feasibility of improving the tumor-targeting efficacy and decreasing the toxicity of liposomal cabazitaxel (Cab) with aptamer modification. The process involved preparing aptamer (TLS1c)-modified liposomes and studying the behavior of the liposomes in vitro and in vivo. TLS1c as an aptamer, which has high specificity for BNL 1ME A.7R.1 (MEAR) cells, was conjugated with Cab liposomes (Cab/lipo) to enhance MEAR tumor tissue targeting. Confocal laser scanning microscopy and flow cytometry analyses demonstrated that the fluorescence of the liposomes modified with the aptamer was notably stronger compared with that of the unmodified liposomes. Furthermore, the biodistribution data of the modified liposomes tested in tumor-bearing mice revealed high specificity of biotinylated TLS1c-modified Cab/lipo (BioTL-Cab/lipo) for tumor tissues. Furthermore, the modified liposomes demonstrated decreased cytotoxicity and simultaneously retained potent inhibition against tumor growth. It is likely that the specific binding of the aptamer (TLS1c) to the targeted cells (MEAR) facilitates the binding of the liposomes to the targeted cells. Therefore, BioTL-Cab/lipo may be considered as a promising delivery system to improve cell targeting and reduce drug toxicity in the treatment of cancer.