Applications of Aptamer-Bound Nanomaterials in Cancer Therapy

Noninvasive Photothermal Therapy of Nasopharyngeal Cancer Guided by High Efficiency Optical-Absorption Nanomaterial Enhanced by NIR-II Photoacoustic Imaging

Background

Photothermal therapy (PTT) guided by photoacoustic imaging (PAI) using nanoplatforms has emerged as a promising strategy for cancer treatment due to its efficiency and accuracy. This study aimed to develop and synthesize novel second near-infrared region (NIR-II) absorption-conjugated polymer acceptor acrylate-substituted thiadiazoloquinoxaline-diketopyrrolopyrrole polymers (PATQ-DPP) designed specifically as photothermal and imaging contrast agents for nasopharyngeal carcinoma (NPC).

Methods

The PATQ-DPP nanoparticles were synthesized and characterized for their optical properties, including low optical band gaps. Their potential as PTT agents and imaging contrast agents for NPC was evaluated both in vitro and in vivo. The accumulation of nanoparticles at tumor sites was assessed post-injection, and the efficacy of PTT under near-infrared laser irradiation was investigated in a mouse model of NPC.

Results

Experimental results indicated that the PATQ-DPP nanoparticles exhibited significant photoacoustic contrast enhancement and favorable PTT performance. Safety and non-toxicity evaluations confirmed the biocompatibility of these nanoparticles. In vivo studies showed that PATQ-DPP nanoparticles effectively accumulated at NPC tumor sites and demonstrated excellent tumor growth inhibition upon exposure to near-infrared laser irradiation. Notably, complete elimination of nasopharyngeal tumors was observed within 18 days following PTT.

Discussion

The findings suggest that PATQ-DPP nanoparticles are a promising theranostic agent for NIR-II PAI and PTT of tumors. This innovative approach utilizing PATQ-DPP nanoparticles provides a powerful tool for the early diagnosis and precise treatment of NPC, offering a new avenue in the management of this challenging malignancy.

Aptamers as an approach to targeted cancer therapy

Conventional cancer treatments can cause serious side effects because they are not specific to cancer cells and can damage healthy cells. Aptamers often are single-stranded oligonucleotides arranged in a unique architecture, allowing them to bind specifically to target sites. This feature makes them an ideal choice for targeted therapeutics. They are typically produced through the systematic evolution of ligands by exponential enrichment (SELEX) and undergo extensive pharmacological revision to modify their affinity, specificity, and therapeutic half-life. Aptamers can act as drugs themselves, directly inhibiting tumor cells. Alternatively, they can be used in targeted drug delivery systems to transport drugs directly to tumor cells, minimizing toxicity to healthy cells. In this review, we will discuss the latest and most advanced approaches to using aptamers for cancer treatment, particularly targeted therapy overcoming resistance to conventional therapies.

Effect of the Formation of Hydrophilic and Hydrophobic-Hydrophilic Associates on the Behavior of Copolymers of N-Vinylpyrrolidone with Methyl Acrylate in Aqueous Solutions

It has been shown that there exist conditions under which thermosensitive copolymers of N-vinylpyrrolidone with methyl acrylate form hydrophobic-hydrophilic associations, which are unstable dynamic meshes, the bonds in which are continuously broken and created again, and the nature of the formation of such meshes depends significantly on the proportion of the hydrophobic component in the copolymer. It is shown that the interaction of the above copolymers with polyacrylic acid results in the formation of not only classical interpolymer complexes, but also hydrophilic interpolymer associates, which also represent unstable networks existing in a dynamic mode. In such meshes, the molecules of the above copolymers serve as a kind of cross-agent connecting the polyacid molecules. There are also conditions under which such meshes acquire a complex structure, since unstable bonds between macromolecular tangles of both the same and different types take part in their formation. It is shown that the transition from the formation of interpolymer complexes to the formation of hydrophilic interpolymer associates can occur, among other things, due to changes in the acidity or concentration of low-molecular salt in solution.

Anti HER-2 aptamer functionalized gold nanoparticles of dasatinib for targeted chemo-radiotherapy in breast cancer cells

In the present study, gold nanoparticles functionalized with anti HER-2 aptamer were designed for effective targeted delivery of dasatinib (DSB) to breast cancer cells. Anti HER-2 aptamer attached to porous or plain gold nanoparticles were compared for dasatinib delivery. Activated drug with succinic anhydride and L-cysteine linker was used for conjugation of DSB to gold nanoparticles. The loading efficiency of the activated drug on plain and porous gold nanoparticles was 52 and 68 %, respectively, which was significantly more than the loading of free DSB in gold nanoparticles (1-2.5 %). The anti HER-2 aptamer was conjugated to porous gold nanoparticles loaded with the activated drug. Various characterization techniques such as FESEM, TEM, AFM, zeta potential and ICP-MS were used to confirm the binding of the drug to gold nanoparticles. 1HNMR and FTIR spectroscopic analyses were employed to examine the structural characteristics of the conjugated drug. These analytical techniques confirmed the successful incorporation of succinyl and thiol groups onto the drug molecule. The amount of aptamer binding to different types of gold nanoparticles was obtained from the intensity of the light emitted from the bands observed in electrophoresis gel and due to the presence of porosity in porous gold nanoparticles, the amount of aptamer conjugation on porous gold nanoparticles increased compared to plain ones. Cell cytotoxicity and cellular uptake were evaluated by MTT assay and TEM in BT-474 and MCF-7 cells. Aptamer-functionalized porous gold nanoparticles containing activated dasatinib showed higher cytotoxicity and cellular uptake than modified DSB-loaded nanoparticles and un-activated DSB. The combination of radiation therapy with the modified dasatinib attached to porous gold nanoparticles and aptamer demonstrated a notable reduction in the IC50 values for both the BT-474 and MCF-7 cell lines. Specifically, the IC50 value for the BT-474 cells decreased from 6.95 μM (for unmodified dasatinib) to 2.57 μM, while for the MCF-7 cells, it decreased from 13.97 μM to 8.57 μM. These findings indicate a significant improvement in the efficacy of the modified dasatinib compared to its unmodified counterpart when used in conjunction with radiation therapy.

Formation of Hydrophobic-Hydrophilic Associates in the N-Vinylpyrrolidone and Vinyl Propyl Ether Copolymer Aqueous Solutions

Utilizing turbidimetry data, an examination is conducted on the behavior of solutions containing N-vinylpyrrolidone and vinyl propyl ether copolymer within a temperature range coinciding with the occurrence of a phase transition. The investigation reveals that within specific conditions prevailing in this domain, the emergence of entities denoted as hydrophobic-hydrophilic associates is conceivable. These entities are characterized by the presence of a relatively dense core, upheld by hydrophobic interplays, and they are proficient in effectively dispersing irradiation within the optical spectrum. Encircling this core is a hydrophilic periphery that impedes the formation of insoluble precipitates. The development of such associates transpires when hydrophobic interactions have attained a discernible prominence, although they remain inadequate to counteract the forces that drive the expansion of macromolecular coils. Under these circumstances, the energetically favored course of action entails the constitution of a core for the aforementioned associates, involving discrete segments from diverse macromolecules. Notably, the introduction of an additional constituent (ethanol) to the solution, which selectively mitigates hydrophobic interactions, serves to stabilize the hydrophobic-hydrophilic associations.

New insight in urological cancer therapy: From epithelial-mesenchymal transition (EMT) to application of nano-biomaterials

A high number of cancer-related deaths (up to 90) are due to metastasis and simple definition of metastasis is new colony formation of tumor cells in a secondary site. In tumor cells, epithelial-mesenchymal transition (EMT) stimulates metastasis and invasion, and it is a common characteristic of malignant tumors. Prostate cancer, bladder cancer and renal cancer are three main types of urological tumors that their malignant and aggressive behaviors are due to abnormal proliferation and metastasis. EMT has been well-documented as a mechanism for promoting invasion of tumor cells and in the current review, a special attention is directed towards understanding role of EMT in malignancy, metastasis and therapy response of urological cancers. The invasion and metastatic characteristics of urological tumors enhance due to EMT induction and this is essential for ensuring survival and ability in developing new colonies in neighboring and distant tissues and organs. When EMT induction occurs, malignant behavior of tumor cells enhances and their tend in developing therapy resistance especially chemoresistance promotes that is one of the underlying reasons for therapy failure and patient death. The lncRNAs, microRNAs, eIF5A2, Notch-4 and hypoxia are among common modulators of EMT mechanism in urological tumors. Moreover, anti-tumor compounds such as metformin can be utilized in suppressing malignancy of urological tumors. Besides, genes and epigenetic factors modulating EMT mechanism can be therapeutically targeted for interfering malignancy of urological tumors. Nanomaterials are new emerging agents in urological cancer therapy that they can improve potential of current therapeutics by their targeted delivery to tumor site. The important hallmarks of urological cancers including growth, invasion and angiogenesis can be suppressed by cargo-loaded nanomaterials. Moreover, nanomaterials can improve chemotherapy potential in urological cancer elimination and by providing phototherapy, they mediate synergistic tumor suppression. The clinical application depends on development of biocompatible nanomaterials.

Aptamers Versus Vascular Endothelial Growth Factor (VEGF): A New Battle against Ovarian Cancer

Cancer is one of the diseases that causes a high mortality as it involves unregulated and abnormal cell growth proliferation that can manifest in any body region. One of the typical ovarian cancer symptoms is damage to the female reproductive system. The death rate can be reduced through early detection of the ovarian cancer. Promising probes that can detect ovarian cancer are suitable aptamers. Aptamers, i.e., so-called chemical antibodies, have a strong affinity for the target biomarker and can typically be identified starting from a random library of oligonucleotides. Compared with other probes, ovarian cancer targeting using aptamers has demonstrated superior detection effectiveness. Various aptamers have been selected to detect the ovarian tumor biomarker, vascular endothelial growth factor (VEGF). The present review highlights the development of particular aptamers that target VEGF and detect ovarian cancer at its earliest stages. The therapeutic efficacy of aptamers in ovarian cancer treatment is also discussed.

Smart Nanomaterials in Cancer Theranostics: Challenges and Opportunities

Cancer is ranked as the second leading cause of death globally. Traditional cancer therapies including chemotherapy are flawed, with off-target and on-target toxicities on the normal cells, requiring newer strategies to improve cell selective targeting. The application of nanomaterial has been extensively studied and explored as chemical biology tools in cancer theranostics. It shows greater applications toward stability, biocompatibility, and increased cell permeability, resulting in precise targeting, and mitigating the shortcomings of traditional cancer therapies. The nanoplatform offers an exciting opportunity to gain targeting strategies and multifunctionality. The advent of nanotechnology, in particular the development of smart nanomaterials, has transformed cancer diagnosis and treatment. The large surface area of nanoparticles is enough to encapsulate many molecules and the ability to functionalize with various biosubstrates such as DNA, RNA, aptamers, and antibodies, which helps in theranostic action. Comparatively, biologically derived nanomaterials perceive advantages over the nanomaterials produced by conventional methods in terms of economy, ease of production, and reduced toxicity. The present review summarizes various techniques in cancer theranostics and emphasizes the applications of smart nanomaterials (such as organic nanoparticles (NPs), inorganic NPs, and carbon-based NPs). We also critically discussed the advantages and challenges impeding their translation in cancer treatment and diagnostic applications. This review concludes that the use of smart nanomaterials could significantly improve cancer theranostics and will facilitate new dimensions for tumor detection and therapy.

Active ingredients of traditional Chinese medicine for enhancing the effect of tumor immunotherapy

Immunotherapy is a type of treatment that uses our own immune system to fight cancer. Studies have shown that traditional Chinese medicine (TCM) has antitumor activity and can enhance host immunity. This article briefly describes the immunomodulatory and escape mechanisms in tumors, as well as highlights and summarizes the antitumor immunomodulatory activities of some representative active ingredients of TCM. Finally, this article puts forward some opinions on the future research and clinical application of TCM, aiming to promote the clinical applications of TCM in tumor immunotherapy and to provide new ideas for the research of tumor immunotherapy using TCM.

A fluorescent probe for protein tyrosine kinase 7 detection in serum and cell imaging

Tyrosine protein kinase 7 (PTK7) is overexpressed in breast cancer, which is considered as a cancer marker for breast cancer diagnosis. Therefore, a simple fluorescent probe for PTK7 detection and cell imaging was developed. In the developed probe, Fe₃O₄ magnetic nanoparticles were used as the fluorescent separator, and the fluorescence of carbon dots were used as the detection signal. The probe was worked by control the configurations of the aptamer of PTK7, the aptamer would be open chains by recognition of PTK7, which bond with carbon dots and show fluorescent signal. Based on the remarkably high affinity and selectivity of aptamer for PTK7, the excellent fluorescence property of carbon dots and the outstanding magnetism of Fe₃O₄ magnetic nanoparticles, the developed probe showed satisfied results for PTK7 detection in serum and MCF-7 cell imaging. The probe detected PTK7 in the range of 0.2-200 ng mL^-1 with a detection limit of 0.0347 ng mL^-1, and successfully imaged the cancer cell expressed PTK7. The results indicate that the nano-fluorescent probe has great potential for clinical applications.

Graphene-Based Electrochemical Biosensors for Breast Cancer Detection

Breast cancer (BC) is the most common cancer in women, which is also the second most public cancer worldwide. When detected early, BC can be treated more easily and prevented from spreading beyond the breast. In recent years, various BC biosensor strategies have been studied, including optical, electrical, electrochemical, and mechanical biosensors. In particular, the high sensitivity and short detection time of electrochemical biosensors make them suitable for the recognition of BC biomarkers. Moreover, the sensitivity of the electrochemical biosensor can be increased by incorporating nanomaterials. In this respect, the outstanding mechanical and electrical performances of graphene have led to an increasingly intense study of graphene-based materials for BC electrochemical biosensors. Hence, the present review examines the latest advances in graphene-based electrochemical biosensors for BC biosensing. For each biosensor, the detection limit (LOD), linear range (LR), and diagnosis technique are analyzed. This is followed by a discussion of the prospects and current challenges, along with potential strategies for enhancing the performance of electrochemical biosensors.

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.

Potential Therapeutic Use of Aptamers against HAT1 in Lung Cancer

Lung cancer is one of the leading causes of death worldwide and the most common of all cancer types. Histone acetyltransferase 1 (HAT1) has attracted increasing interest as a potential therapeutic target due to its involvement in multiple pathologies, including cancer. Aptamers are single-stranded RNA or DNA molecules whose three-dimensional structure allows them to bind to a target molecule with high specificity and affinity, thus making them exceptional candidates for use as diagnostic or therapeutic tools. In this work, aptamers against HAT1 were obtained, subsequently characterized, and optimized, showing high affinity and specificity for HAT1 and the ability to inhibit acetyltransferase activity in vitro. Of those tested, the apHAT610 aptamer reduced cell viability, induced apoptosis and cell cycle arrest, and inhibited colony formation in lung cancer cell lines. All these results indicate that the apHAT610 aptamer is a potential drug for the treatment of lung cancer.

Nanoprobes for Tumor Theranostics

This Special Issue of Biosensors, entitled "Nanoprobes for Tumor Theranostics", aims to report the research progress of using nanoprobes for the diagnosis and therapy of tumors, and promote their applications [...].