AS1411-functionalized delivery nanosystems for targeted cancer therapy

Formulation optimization of lyophilized aptamer-gold nanoparticles: Maintained colloidal stability and cellular uptake

Anti-nucleolin (NCL) aptamer AS1411 is the first anticancer aptamer tested in clinical trials. Gold nanoparticles (AuNP) have been widely exploited for various biomedical applications due to their unique functional properties. In this study, we evaluated the colloidal stability and targeting capacity of AS1411-funtionalized AuNP (AuNP/NCL-Apt) against MCF-7 breast cancer cell line before and after lyophilization. Trehalose, mannitol, and sucrose at various concentrations were evaluated to determine their cryoprotection effects. Our results indicate that sucrose at 10 % (w/v) exhibits the best cryoprotection effect and minimal AuNP/NCL-Apt aggregation as confirmed by UV-Vis spectroscopy and dynamic light scattering (DLS) measurements. Moreover, the lyophilized AuNP/NCL-Apt at optimized formulation maintained its targeting and cytotoxic functionality against MCF-7 cells as proven by the cellular uptake assays utilizing flow cytometry and confocal laser scanning microscopy (CLSM). Quantitative PCR (qPCR) analysis of nucleolin-target gene expression also confirmed the effectiveness of AuNP/NCL-Apt. This study highlights the importance of selecting the proper type and concentration of cryoprotectant in the typical nanoparticle lyophilization process and contributes to our understanding of the physical and biological properties of functionalized nanoparticles upon lyophilization.

Aptamer-based Advances in Skin Cancer Research

Cancer diseases have been one of the biggest health threats for the last two decades. Approximately 9% of all diagnosed cancers are skin cancers, including melanoma and non-melanoma. In all cancer cases, early diagnosis is essential to achieve efficient treatment. New solutions and advanced techniques for rapid diagnosis are constantly being sought. Aptamers are single-stranded RNA or DNA synthetic sequences or peptides, which offer novel possibilities to this area of research by specifically binding selected molecules, the so-called cancer biomarkers. Nowadays, they are widely used as diagnostic probes in imaging and targeted therapy. In this review, we have summarized the recently made advances in diagnostics and treatment of skin cancers, which have been achieved by combining aptamers with basic or modern technologies.

Aptamers as Theragnostic Tools in Prostate Cancer

Despite of the capacity that several drugs have for specific inhibition of the androgen receptor (AR), in most cases, PCa progresses to an androgen-independent stage. In this context, the development of new targeted therapies for prostate cancer (PCa) has remained as a challenge. To overcome this issue, new tools, based on nucleic acids technology, have been developed. Aptamers are small oligonucleotides with a three-dimensional structure capable of interacting with practically any desired target, even large targets such as mammalian cells or viruses. Recently, aptamers have been studied for treatment and detection of many diseases including cancer. In PCa, numerous works have reported their use in the development of new approaches in diagnostics and treatment strategies. Aptamers have been joined with drugs or other specific molecules such as silencing RNAs (aptamer–siRNA chimeras) to specifically reduce the expression of oncogenes in PCa cells. Even though these studies have shown good results in the early stages, more research is still needed to demonstrate the clinical value of aptamers in PCa. The aim of this review was to compile the existing scientific literature regarding the use of aptamers in PCa in both diagnosis and treatment studies. Since Prostate-Specific Membrane Antigen (PSMA) aptamers are the most studied type of aptamers in this field, special emphasis was given to these aptamers.