Nanotechnology and Glycosaminoglycans: Paving the Way Forward for Ovarian Cancer Intervention

Computable structured aptamer for targeted treatment of ovarian cancer

Nucleolin protein expression is higher on the ovarian cancer cell surface. AS1411, a DNA aptamer, can bind with nucleolin protein specifically. In this study, we developed HA and ST DNA tiles to assemble six AS1411 aptamers to deliver doxorubicin. In addition, to superior serum stability and drug loading, HA-6AS and ST-6AS outperformed TDN-AS in cellular uptake. HA-6AS and ST-6AS exhibited satisfactory targeted cytotoxicity and achieved resounding lysosomal escape. Moreover, when injected into nude mice subcutaneous xenograft models, HA-6AS reached the peak in tumor more quickly than ST-6AS, and better expressed the active targeting ability of AS1411. Our study suggests that designing appropriate DNA tiles to assemble different aptamers to deliver different chemotherapeutic drugs is a promising treatment for ovarian cancer.

Application of aptamer functionalized nanomaterials in targeting therapeutics of typical tumors

Cancer is a major cause of human death all over the world. Traditional cancer treatments include surgery, radiotherapy, chemotherapy, immunotherapy, and hormone therapy. Although these conventional treatment methods improve the overall survival rate, there are some problems, such as easy recurrence, poor treatment, and great side effects. Targeted therapy of tumors is a hot research topic at present. Nanomaterials are essential carriers of targeted drug delivery, and nucleic acid aptamers have become one of the most important targets for targeted tumor therapy because of their high stability, high affinity, and high selectivity. At present, aptamer-functionalized nanomaterials (AFNs), which combine the unique selective recognition characteristics of aptamers with the high-loading performance of nanomaterials, have been widely studied in the field of targeted tumor therapy. Based on the reported application of AFNs in the biomedical field, we introduce the characteristics of aptamer and nanomaterials, and the advantages of AFNs first. Then introduce the conventional treatment methods for glioma, oral cancer, lung cancer, breast cancer, liver cancer, colon cancer, pancreatic cancer, ovarian cancer, and prostate cancer, and the application of AFNs in targeted therapy of these tumors. Finally, we discuss the progress and challenges of AFNs in this field.

A Preparation Method of Nano-Pesticide Improves the Selective Toxicity toward Natural Enemies

Various nano-delivery systems have been designed to deliver synthetic/botanical pesticides for improved bioactivity. However, the enhanced toxicity of nanocarrier-loaded pesticides may injure the natural enemies, and their selective toxicity should be evaluated before the large-scale application. In this context, a star polymer (SPc)-based cyantraniliprole (CNAP) nano-delivery system was constructed, and its selective toxicity was evaluated using pest Frankliniella occidentalis (WFT) and predator Orius sauteri. The amide NH of CNAP could assemble with carbonyl groups or tertiary amines of SPc through hydrogen bonds to form CNAP/SPc complex spontaneously. The above self-assembly decreased the particle size of CNAP from 808 to 299 nm. With the help of SPc, the lethal concentration 50 (LC₅₀) values of CNAP decreased from 99 to 54 mg/L and 230 to 173 mg/L toward WFTs and O. sauteri due to the enhancement of broad-spectrum bioactivity. Interestingly, the toxicity selective ratio (TSR) of CNAP increased from 2.33 to 3.23 with the help of SPc, revealing the higher selectivity of SPc-loaded CNAP. To our knowledge, it was the first successful exploration of the selective toxicity of nanocarrier-loaded pesticides, and the higher selective toxicity of SPc-loaded CNAP was beneficial for alleviating the negative impacts on predators.

Applications of Aptamers in the Diagnosis and Treatment of Ovarian Cancer: Progress From 2016 to 2020

Nucleic acid aptamers are short single-stranded DNA or RNA oligonucleotides selected from a random single-stranded nucleic acid library using systematic evolution of ligands by exponential enrichment technology. To allow them to bind to molecular targets with the same specificity and precision as that of antibodies, aptamers are folded into secondary or tertiary structures. However, compared to antibodies, aptamers are not immunogenic and are easier to synthesize. Furthermore, they are chemically modified, which protects them from degradation by nucleases. Hence, due to their stability and favorable targeting ability, aptamers are promising for the diagnosis and treatment of diseases. Ovarian cancer has the worst prognosis among all gynecological diseases and is usually diagnosed at the medium and advanced stages due to its nonspecific symptoms. Relapse is common, even if patients receive a standard therapeutic regimen including surgery and chemotherapy; simultaneously, drug resistance and adverse effects are reported in a several patients. Therefore, the safer and more efficient diagnostic and treatment method for ovarian cancer is imperative. Scientists have been trying to utilize aptamer technology for the early diagnosis and accurate treatment of ovarian cancer and some progress has been made in this field. This review discusses the screening of nucleic acid aptamers by targeting ovarian cancer cells and the application of aptamers in the diagnosis and treatment of ovarian cancer.

Multifunctional Magnetic Nanowires: Design, Fabrication, and Future Prospects as Cancer Therapeutics

Traditional cancer therapeutics are limited by factors such as multi-drug resistance and a plethora of adverse effect. These limitations need to be overcome for the progression of cancer treatment. In order to overcome these limitations, multifunctional nanosystems have recently been introduced into the market. The employment of multifunctional nanosystems provide for the enhancement of treatment efficacy and therapeutic effect as well as a decrease in drug toxicity. However, in addition to these effects, magnetic nanowires bring specific advantages over traditional nanoparticles in multifunctional systems in terms of the formulation and application into a therapeutic system. The most significant of which is its larger surface area, larger net magnetic moment compared to nanoparticles, and interaction under a magnetic field. This results in magnetic nanowires producing a greater drug delivery and therapeutic platform with specific regard to magnetic drug targeting, magnetic hyperthermia, and magnetic actuation. This, in turn, increases the potential of magnetic nanowires for decreasing adverse effects and improving patient therapeutic outcomes. This review focuses on the design, fabrication, and future potential of multifunctional magnetic nanowire systems with the emphasis on improving patient chemotherapeutic outcomes.