Nanomaterials for the Capture and Therapeutic Targeting of Circulating Tumor Cells

Magnetically-activated, nanostructured cellulose for efficient capture of circulating tumor cells from the blood sample of head and neck cancer patients

In this report, the relative efficiency of cellulose nanocrystals (CNCs) and nanofibers (CNFs) to capture circulating tumor cells (CTCs) from the blood sample of head and neck cancer (HNC) patients was evaluated. Detection and enumeration of CTCs are critical for monitoring cancer progression. Both types of nanostructured cellulose were chemically modified with Epithelial Cell Adhesion Molecule (EpCAM) antibody and iron oxide nanoparticles. The EpCAM antibody facilitated the engagement of CTCs, promoting entrapment within the cellulose cage structure. Iron oxide nanoparticles, on the other hand, rendered the cages activatable via the use of a magnet for the capture and separation of entrapped CTCs. The efficiency of the network structures is shown in head and neck cancer (HNC) patients' blood samples. It was observed that the degree of chemical functionalization of hydroxyl groups located within the CNCs or CNFs with anti-EpCAM determined the efficiency of the system's interaction with CTCs. Further, our result indicated that inflexible scaffolds of nanocrystals interacted more efficiently with CTCs than that of the fibrous CNF scaffolds. Network structures derived from CNCs demonstrated comparable CTC capturing efficiency to commercial standard, OncoDiscover®. The output of the work will provide the chemical design principles of cellulosic materials intended for constructing affordable platforms for monitoring cancer progression in 'real time'.

Recent advancement of nanomedicine-based targeted delivery for cervical cancer treatment

Cervical cancer is a huge worldwide health burden, impacting women in impoverished nations in particular. Traditional therapeutic approaches, such as surgery, radiation therapy, and chemotherapy, frequently result in systemic toxicity and ineffectiveness. Nanomedicine has emerged as a viable strategy for targeted delivery of therapeutic drugs to cancer cells while decreasing off-target effects and increasing treatment success in recent years. Nanomedicine for cervical cancer introduces several novel aspects that distinguish it from previous treatment options such as tailored delivery system, precision targeting, combination therapies, real-time monitoring and diverse nanocarriers to overcome the limitations of one another. This abstract presents recent advances in nanomedicine-based tailored delivery systems for the treatment of cervical cancer. Liposomes, polymeric nanoparticles, dendrimers, and carbon nanotubes have all been intensively studied for their ability to transport chemotherapeutic medicines, nucleic acids, and imaging agents to cervical cancer cells. Because of the way these nanocarriers are designed, they may cross biological barriers and preferentially aggregate at the tumor site, boosting medicine concentration and lowering negative effects on healthy tissues. Surface modification of nanocarriers with targeting ligands like antibodies, peptides, or aptamers improves specificity for cancer cells by identifying overexpressed receptors or antigens on the tumor surface. Furthermore, nanomedicine-based techniques have made it possible to co-deliver numerous therapeutic drugs, allowing for synergistic effects and overcoming drug resistance. In preclinical and clinical investigations, combination treatments comprising chemotherapeutic medicines, gene therapy, immunotherapy, and photodynamic therapy have showed encouraging results, opening up new avenues for individualized and multimodal treatment regimens. Furthermore, the inclusion of contrast agents and imaging probes into nanocarrier systems has enabled real-time monitoring and imaging of treatment response. This enables the assessment of therapy efficacy, the early diagnosis of recurrence, and the optimization of treatment regimens.

Recent Update Roles of Magnetic Nanoparticles in Circulating Tumor Cell (CTC)/Non-CTC Separation

Metastasis of cancer is a major cause of death worldwide. Circulating tumor cells (CTCs) are important in the metastatic process of cancer. CTCs are able to circulate in the bloodstream. Therefore, they can be used as biomarkers of metastasis. However, CTCs are rare when compared to a large number of blood cells in the blood. Many CTC detection methods have been developed to increase CTC detection efficiency. Magnetic nanoparticles (MNPs) have attracted immense attention owing to their potential medical applications. They are particularly appealing as a tool for cell separation. Because of their unique properties, MNPs are of considerable interest for the enrichment of CTCs through CTC or non-CTC separation. Herein, we review recent developments in the application of MNPs to separate CTCs or non-CTCs in samples containing CTCs. This review provides information on new approaches that can be used to detect CTCs in blood samples. The combination of MNPs with other particles for magnetic-based cell separation for CTC detection is discussed. Furthermore, different approaches for synthesizing MNPs are included in this review.

Dopamine-Conjugated Bovine Serum Albumin Nanoparticles Containing pH-Responsive Catechol-V(III) Coordination for In Vitro and In Vivo Drug Delivery

V(III) instead of commonly used Fe(III) provided a rich tris-catechol-metal coordination at pH 7.4, which is important for slow drug release at physiological pH. Bovine serum albumin (BSA) functionalized with catechol-containing dopamine (D) and cross-linked using tris-catechol-V(III) coordination yielded pH-responsive compact D-BSA NPs (253 nm). However, conversion to bis- and/or mono-catechol-V(III) complexes in an acidic medium resulted in degradation of NPs and rapid release of doxorubicin (DOX). It was shown that D-BSA NPs entered cancerous MCF-7 cells (66%) more efficiently than non-cancerous HEK293T (33%) in 3 h. Also, DOX-loaded NPs reduced cell viability of MCF-7 by 75% and induced apoptosis in a majority of cells after 24 h. Biodegradability and lack of hemolytic activity were shown in vitro, whereas a lack of toxicity was shown in histological sections of zebrafish. Furthermore, 30% of circulating tumor cells in vasculature in 24 h were killed by DOX-loaded NPs shown with the zebrafish CTC xenograft model.

Capture and release of circulating tumor cells stimulated by pH and NIR irradiation of magnetic Fe3O4@ZIF-8 nanoparticles

Detecting and analyzing circulating tumor cells(CTCs) is significant for early diagnosis, management, and personalized treatment of tumors. Herein, a smart magnetic aptamer modified Fe₃O₄@ZIF-8 core/shell structured nanoparticle (NPs) was successfully constructed using for capture and simultaneous pH- and NIR-irradiation responsive release of CTCs. Taking MCF-7 as model CTCs, it could be captured ca. 60 % in low-concentration artificial blood by aptamer (SYL3C) on the surface of Fe₃O₄@ZIF-8 NPs. After magnetic separation, the ZIF-8 shell in aptamer-modified Fe₃O₄@ZIF-8 NPs carrying captured CTCs would disintegrate within 20 min under the synergistic effect of an acidic environment (pH=6.0) and NIR irradiation leading to the release of CTCs with high cell viability, which was benefited for the subsequent culture and analysis. This magnetic and core/shell structured device integrated high-efficiency capture, quick isolation and perfect release into one system, which showed great potentials for the detection of CTCs in the clinic.

Nanoparticle-mediated therapeutic management in cholangiocarcinoma drug targeting: Current progress and future prospects

Patients with cholangiocarcinoma (CCA) often have an unfavorable prognosis because of its insidious nature, low resectability rate, and poor response to anticancer drugs and radiotherapy, which makes early detection and treatment difficult. At present, CCA has a five-year overall survival rate (OS) of only 5%, despite advances in therapies. New an increasing number of evidence suggests that nanoplatforms may play a crucial role in enhancing the pharmacological effects and in reducing both short- and long-term side effects of cancer treatment. This document reviews the advantages and shortcomings of nanoparticles such as liposomes, polymeric nanoparticle，inorganic nanoparticle, nano-metals and nano-alloys, carbon dots, nano-micelles, dendrimer, nano-capsule, bio-Nanomaterials in the diagnosis and treatment of CCA and discuss the current challenges in of nanoplatforms for CCA.

An Implantable Magnetic Vascular Scaffold for Circulating Tumor Cell Removal In Vivo

An integrated trapped device (ITD) capable of removal of circulating tumor cells (CTCs) can assuage or even prevent metastasis. However, adhesion repertoires are ordinarily neglected in the design of ITDs, possibly leading to the omission of highly metastatic CTC and treatment failure. Here a vascular-like ITD with adhesive sites and wireless magnetothermal response to remove highly metastatic CTC in vivo is presented. Such a vascular-like ITD comprises circumferential well-aligned fibers and artificial adhesion repertoires and is optimized for magnetothermal integration. Continuous and repeated capture in a dynamic environment increases capture efficiency over time. Meanwhile, the heat generation of the ITD leads to the capture of CTC death owing to cell heat sensitivity. Furthermore, the constructed bioinspired ultrastructure of the ITD prevents vascular blockage and induces potential vascular regeneration. Overall, this work defines an extendable strategy for constructing adhesion repertoires against intravascular shear forces, provides a vascular-like ITD for reducing CTC counts, and is expected to alleviate the risk of cancer recurrence.

Optical cytosensors for the detection of circulating tumour cells

Blood analysis is an established approach to monitor various diseases, ranging from heart defects and diabetes to cancer. Among various tumor markers in the blood, circulating tumor cells (CTCs) have received increasing attention due to the fact that they originate directly from the tumors. Capturing and detecting CTCs represents a promising approach in cancer diagnostics and clinical management of cancers. CTCs in blood progress to self-seeding a tumour or initiating a new lesion mass. Cytosensors are biosensors intended to identify CTCs in a blood sample of cancer patients and provide information about the cancer status. Herein, we firstly discuss different detection methods of state-of-the-art optical cytosensors, including colorimetry, fluorescence, surface plasmon resonance, photoelectrochemistry and electrochemiluminescence. Then we review the significant advances made in implementing biorecognition elements and nanomaterials for the detection of cancer cells. Despite great progress in optical cytosensors, and their integration with smartphones, they have still only been explored to prototype stages. Much more effort is needed to fulfil their potential in modern cancer diagnostics and in monitoring the state of disease for cancer patients.

Modification of Hemodialysis Membranes for Efficient Circulating Tumor Cell Capture for Cancer Therapy

Background: It is well known that more than 90% of cancer deaths are due to metastases. However, the entire tumorigenesis process is not fully understood, and it is evident that cells spreading from the primary tumor play a key role in initiating the metastatic process. Tumor proliferation and invasion also elevate the concentration of regular and irregular metabolites in the serum, which may alter the normal function of the entire human homeostasis and possibly causes cancer metabolism syndrome, also referred to as cachexia. Methods: We report on the modification of commercially available hemodialysis membranes to selectively capture circulating tumor cells from the blood stream by means of immobilized human anti-EpCAM antibodies on the inner surface of the fibers. All critical steps are described that required in situ addition of the immuno-affinity feature to hemodialyzer cartridges in order to capture EpCAM positive circulating tumor cells, which represents ~80% of cancer cell types. Results: The cell capture efficiency of the suggested technology was demonstrated by spiking HCT116 cancer cells both into buffer solution and whole blood and run through on the modified cartridge. Flow cytometry was used to quantitatively evaluate the cell clearance performance of the approach. Conclusions: The suggested modification has no significant effect on the porous structure of the hemodialysis membranes; it keeps its cytokine removal capability, addressing cachexia simultaneously with CTC removal.

Metastasis Prevention: Focus on Metastatic Circulating Tumor Cells

Metastasis is the main cause of cancer death. Metastatic foci are derived from tumor cells that detach from the primary tumor and then enter the circulation. Circulating tumor cells (CTCs) are generally associated with a high probability of distant metastasis and a negative prognosis. Most CTCs die in the bloodstream, and only a few cells form metastases. Such metastatic CTCs have a stem-like and hybrid epithelial-mesenchymal phenotype, can avoid immune surveillance, and show increased therapy resistance. Targeting metastatic CTCs and their progenitors in primary tumors and their descendants, particularly disseminated tumor cells, represents an attractive strategy for metastasis prevention. However, current therapeutic strategies mainly target the primary tumor and only indirectly affect metastasis-initiating cells. Here, we consider potential methods for preventing metastasis based on targeting molecular and cellular features of metastatic CTCs, including CTC clusters. Also, we emphasize current knowledge gaps in CTC biology that should be addressed to develop highly effective therapeutics and strategies for metastasis suppression.

Design and Engineering of Hypoxia and Acidic pH Dual-Stimuli-Responsive Intelligent Fluorescent Nanoprobe for Precise Tumor Imaging

Stimulus-responsive fluorescence imaging modality shows great promise for detection of tumor due to the advantages of high sensitivity, simplicity and noninvasiveness. However, some non-cancer regions including nodules and inflammation may also exhibit a stimulus-related characteristic, which cause the problem of nonspecific responsiveness and then cause "false positive" results for tumor recognition. Herein, hypoxia and acidic pH, two typical features strongly associated with tumor invasion, progression and metastasis in tumor microenvironment (TME), are chosen as dual stimuli to fabricate "dual lock-and-key" fluorescent nanoprobe for highly specific and precise imaging of tumor cells. Mesoporous silica coated gold nanorods (AuNR@mSiO₂ ) are employed as nanocarrier and nanoquencher to load the pH-sensitive fluorescent reporter (Rho-TP). Azobenzene (azo) which can be reduced to amines by the highly expressed azoreductase under hypoxic conditions, is elected as the effective gatekeeper for AuNR@mSiO₂ by forming complex with β-cyclodextrin polymer via host-guest interaction (azo/β-CDP). By elaborately combining the hypoxia-responsive gatekeeper and pH-responsive fluorescent signal reporter into one nanoprobe, sensitive and specific imaging of tumor cells can be realized. The fabricated dual lock-and-key fluorescent nanoprobe successfully further apply in tumor-bearing mice model, which indicate potential of early diagnosis and assessment of cancer treatment.

Live long and active: Polypeptide-mediated assembly of antibody variable fragments

Antibodies possess multiple biologically relevant features that have been engineered into new therapeutic formats. Two examples include the adaptable specificity of their variable (Fv) region and the extension of plasma circulation times through their crystallizable (Fc) region. Since the invention of the single chain variable fragment (scFv) in 1988, antibody variable regions have been re-engineered into a wide variety of multifunctional nanostructures. Among these strategies, peptide-mediated self-assembly of variable regions through heterologous expression has become a powerful method to produce homogenous, functional biomaterials. This manuscript reviews recent reports of antibody fragments assembled through fusion with peptides and proteins, including elastin-like polypeptides (ELPs), collagen-like polypeptides (CLPs), albumin, transmembrane proteins, leucine zippers, silk protein, and viruses. This review further discusses the current clinical status of engineered antibody fragments and challenges to overcome.

A simplified method for the efficient purification and refolding of recombinant human TRAIL

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) belongs to the TNF cytokine superfamily that specifically induces apoptosis in a broad spectrum of human cancer cell lines but not in most healthy cells. The antitumor potential of recombinant human TRAIL (rhTRAIL) has attracted great attention among biologists and oncologists. However, attempts to express rhTRAIL in Escherichia coli often results in limited yield of bioactive protein due to the formation of inclusion bodies (IBs), which are dense insoluble particulate protein aggregates inside cells. We describe herein a highly simplified method to produce pure bioactive rhTRAIL using E. coli. The method is straightforward and requires only basic laboratory equipment, with highly efficient purification and high yield of renaturation, and may also be applied to produce other proteins that form IBs in E. coli.

Nano Meets Micro-Translational Nanotechnology in Medicine: Nano-Based Applications for Early Tumor Detection and Therapy

Nanomaterials have great potential for the prevention and treatment of cancer. Circulating tumor cells (CTCs) are cancer cells of solid tumor origin entering the peripheral blood after detachment from a primary tumor. The occurrence and circulation of CTCs are accepted as a prerequisite for the formation of metastases, which is the major cause of cancer-associated deaths. Due to their clinical significance CTCs are intensively discussed to be used as liquid biopsy for early diagnosis and prognosis of cancer. However, there are substantial challenges for the clinical use of CTCs based on their extreme rarity and heterogeneous biology. Therefore, methods for effective isolation and detection of CTCs are urgently needed. With the rapid development of nanotechnology and its wide applications in the biomedical field, researchers have designed various nano-sized systems with the capability of CTCs detection, isolation, and CTCs-targeted cancer therapy. In the present review, we summarize the underlying mechanisms of CTC-associated tumor metastasis, and give detailed information about the unique properties of CTCs that can be harnessed for their effective analytical detection and enrichment. Furthermore, we want to give an overview of representative nano-systems for CTC isolation, and highlight recent achievements in microfluidics and lab-on-a-chip technologies. We also emphasize the recent advances in nano-based CTCs-targeted cancer therapy. We conclude by critically discussing recent CTC-based nano-systems with high therapeutic and diagnostic potential as well as their biocompatibility as a practical example of applied nanotechnology.

Detection of HER2+ Breast Cancer Cells using Bioinspired DNA-Based Signal Amplification

Circulating tumor cells (CTC) are promising biomarkers for metastatic cancer detection and monitoring progression. However, detection of CTCs remains challenging due to their low frequency and heterogeneity. Herein, we report a bioinspired approach to detect individual cancer cells, based on a signal amplification cascade using a programmable DNA hybridization chain reaction (HCR) circuit. We applied this approach to detect HER2⁺ cancer cells using the anti‐HER2 antibody (trastuzumab) coupled to initiator DNA eliciting a HCR cascade that leads to a fluorescent signal at the cell surface. At 4 °C, this HCR detection scheme resulted in highly efficient, specific and sensitive signal amplification of the DNA hairpins specifically on the membrane of the HER2⁺ cells in a background of HER2⁻ cells and peripheral blood leukocytes, which remained almost non‐fluorescent. The results indicate that this system offers a new strategy that may be further developed toward an in vitro diagnostic platform for the sensitive and efficient detection of CTC.

Treating tumors with minimally invasive therapy: A review

With high level of morbidity and mortality, tumor is one of the deadliest diseases worldwide. Aiming to tackle tumor, researchers have developed a lot of strategies. Among these strategies, the minimally invasive therapy (MIT) is very promising, for its capability of targeting tumor cells and resulting in a small incision or no incisions. In this review, we will first illustrate some mechanisms and characteristics of tumor metastasis from the primary tumor to the secondary tumor foci. Then, we will briefly introduce the history, characteristics, and advantages of some of the MITs. Finally, emphasis will be, respectively, focused on an overview of the state-of-the-art of the HIFU-, PDT-, PTT-and SDT-based anti-tumor strategies on each stage of tumor metastasis.

Is small smarter? Nanomaterial-based detection and elimination of circulating tumor cells: current knowledge and perspectives

Circulating tumor cells (CTCs) are disseminated cancer cells. The occurrence and circulation of CTCs seem key for metastasis, still the major cause of cancer-associated deaths. As such, CTCs are investigated as predictive biomarkers. However, due to their rarity and heterogeneous biology, CTCs’ practical use has not made it into the clinical routine. Clearly, methods for the effective isolation and reliable detection of CTCs are urgently needed. With the development of nanotechnology, various nanosystems for CTC isolation and enrichment and CTC-targeted cancer therapy have been designed. Here, we summarize the relationship between CTCs and tumor metastasis, and describe CTCs’ unique properties hampering their effective enrichment. We comment on nanotechnology-based systems for CTC isolation and recent achievements in microfluidics and lab-on-a-chip technologies. We discuss recent advances in CTC-targeted cancer therapy exploiting the unique properties of nanomaterials. We conclude by introducing developments in CTC-directed nanosystems and other advanced technologies currently in (pre)clinical research.

[The liquid biopsies: What is their contribution to the management of cancer?]

The « liquid biopsies » are samples of liquids such as blood, urine, spinal fluid that can contain tumor material. Clinical assays have been mainly focused on the peripheral blood containing circulating tumor cells and circulating tumor DNA. The circulating tumor cells are cancer cells released from the primary tumor or recurrences or metastases. They enter into the bloodstream after passing through the vessel wall. It is possible to analyze the circulating tumor cells by means of all cytologic and biomolecular techniques. The free circulating tumor DNA is made of fragments of DNA released by living or necrotic tumor cells proceeded from any place of the organism. The free circulating tumor DNA and DNA from circulating tumor cells show structural rearrangements among which some are therapeutic targets. Many studies showed that circulating tumor cells and circulating tumor DNA analyses are useful in revealing recurrences and tracking therapeutic targets.

Functional Diagnostic and Therapeutic Nanoconstructs for Efficient Probing of Circulating Tumor Cells

The circulation of tumor cells in peripheral blood is mostly recognized as a prerequisite for cancer progression or systemic invasion, and it correlates with the pivotal hallmark of malignancies known as metastasis. Multiple detection schemes for circulating tumor cells (CTCs) have emerged as the most discerning criteria for monitoring the outcome of anticancer therapy. Therefore, there has been a tremendous increase in the use of robust nanostructured platforms for observation of these mobile tumor cells through various simultaneous diagnosis and treatment regimens developed from conventional techniques. This review seeks to give detailed information about the nature of CTCs as well as techniques for exploiting specific biomarkers to help monitor cancer via detection, capturing, and analysis of unstable tumor cells. We will further discuss nanobased diagnostic interventions and novel platforms which have recently been developed from versatile nanomaterials such as polymer nanocomposites, metal organic frameworks, bioderived nanomaterials and other physically responsive particles with desirable intrinsic and external properties. Herein, we will also include in vivo nanotheranostic platforms which have received a lot of attention because of their enormous clinical potential. In all, this review sums up the general potential of key promising nanoinspired systems as well as other advanced strategies under research and those in clinical use.