LNA aptamer based multi-modal, Fe3O4-saturated lactoferrin (Fe3O4-bLf) nanocarriers for triple positive (EpCAM, CD133, CD44) colon tumor targeting and NIR, MRI and CT imaging

Synergistic effect of photothermal and magnetic hyperthermia for in situ activation of Fenton reaction in tumor microenvironment for chemodynamic therapy

Traditional cancer treatments are ineffective and cause severe adverse effects. Thus, the development of chemodynamic therapy (CDT) has the potential for in situ catalysis of endogenous molecules into highly toxic species, which would then effectively destroy cancer cells. However, the shortage of high-performance nanomaterials hinders the broad clinical application of this approach. In present study, an effective therapeutic platform was developed using a simple hydrothermal method for the in-situ activation of the Fenton reaction within the tumor microenvironment (TME) to generate substantial quantities of •OH and ultimately destroy cancer cells, which could be further synergistically increased by photothermal therapy (PHT) and magnetic hyperthermia (MHT) aided by FeMoO4 nanorods (NRs). The produced FeMoO4 NRs were used as MHT/PHT and Fenton catalysts. The photothermal conversion efficiency of the FeMoO4 NRs was 31.75 %. In vitro and \ experiments demonstrated that the synergistic combination of MHT/PHT/CDT notably improved anticancer efficacy. This work reveals the significant efficacy of CDT aided by both photothermal and magnetic hyperthermia and offers a feasible strategy for the use of iron-based nanoparticles in the field of biomedical applications.

Tissue-specific cancer stem/progenitor cells: Therapeutic implications

Surgical resection, chemotherapy, and radiation are the standard therapeutic modalities for treating cancer. These approaches are intended to target the more mature and rapidly dividing cancer cells. However, they spare the relatively quiescent and intrinsically resistant cancer stem cells (CSCs) subpopulation residing within the tumor tissue. Thus, a temporary eradication is achieved and the tumor bulk tends to revert supported by CSCs' resistant features. Based on their unique expression profile, the identification, isolation, and selective targeting of CSCs hold great promise for challenging treatment failure and reducing the risk of cancer recurrence. Yet, targeting CSCs is limited mainly by the irrelevance of the utilized cancer models. A new era of targeted and personalized anti-cancer therapies has been developed with cancer patient-derived organoids (PDOs) as a tool for establishing pre-clinical tumor models. Herein, we discuss the updated and presently available tissue-specific CSC markers in five highly occurring solid tumors. Additionally, we highlight the advantage and relevance of the three-dimensional PDOs culture model as a platform for modeling cancer, evaluating the efficacy of CSC-based therapeutics, and predicting drug response in cancer patients.

Advanced cancer targeting using aptamer functionalized nanocarriers for site-specific cargo delivery

The non-specificity of standard anticancer therapies has profound detrimental consequences in clinical treatment. Therapeutic specificity can be precisely achieved using cutting-edge ligands. Small synthetic oligonucleotide-ligands chosen through Systematic evolution of ligands by exponential enrichment (SELEX) would be an unceasing innovation in using nucleic acids as aptamers, frequently referred to as "chemical antibodies." Aptamers act as externally controlled switching materials that can attach to various substrates, for example, membrane proteins or nucleic acid structures. Aptamers pose excellent specificity and affinity for target molecules and can be used as medicines to suppress tumor cell growth directly. The creation of aptamer-conjugated nanoconstructs has recently opened up innovative options in cancer therapy that are more effective and target tumor cells with minor toxicity to healthy tissues. This review focuses on a comprehensive description of the most capable classes of aptamer-tethered nanocarriers for precise recognition of cancer cells with significant development in proficiency, selectivity, and targetability for cancer therapy. Existing theranostic applications with the problems and future directions are also highlighted.

Aptamers and nanobodies as alternatives to antibodies for ligand-targeted drug delivery in cancer

Targeted drug delivery (TDD) is the selective delivery of a therapeutic agent specifically to the site of action to avoid adverse effects and systemic toxicity and to reduce the dose required. Ligand TDD or active TDD involves using a ligand-drug conjugate comprising a targeting ligand linked to an active drug moiety that can either be free or encapsulated within a nanocarrier (NC). Aptamers are single-stranded oligonucleotides that bind to specific biomacromolecules because of their 3D conformation. Nanobodies are the variable domains of unique heavy chain-only antibodies (HcAbs) produced by animals of the Camelidae family. Both these types of ligand are smaller than antibodies and have been used to efficiently target drugs to particular tissues or cells. In this review, we describe the applications of aptamers and nanobodies as ligands for TDD, their advantages and disadvantages compared with antibodies, and the various modalities for targeting cancers using these ligands. Teaser: Aptamers and nanobodies are macromolecular ligands that can actively chaperone drug molecules to particular cancerous cells or tissues in the body to target their pharmacological effects and improve their therapeutic index and safety.

Evaluation of cytotoxicity, reactive oxygen species and nitrous oxide of nanochitosan from shrimp shell

This work aims to synthesize, characterize and evaluate the biological activity of nanochitosan (NQ) prepared from shrimp, showing an innovative character and correlating with sustainable development, in promoting an alternative to the solid waste (shrimp) shell and a biological application of the novel nanomaterial. The NQ synthesis was carried out by the alkaline deacetylation process of chitin obtained of the demineralization, deproteinization and deodorization steps from shrimp shells. NQ was characterized by X-ray Powder Diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), N₂ porosimetry (BET/BJH methods), zeta potential (ZP) and zero charge point (pH_ZCP). To evaluate the safety profile was carried out the cytotoxicity, DCFHA and NO tests in 293T and HaCat cell lines. Regarding the cell viability, NQ did not show toxicity for the tested cell lines. In the evaluation of the ROS production and NO tests, there was no increase in the levels of free radicals and between the negative control, respectively. Therefore, NQ does not present cytotoxicity in the cell lines tested (10, 30, 100 and 300 μg mL^-1), proposing new perspectives on the use of NQ as a potential nanomaterial for biomedical applications.

Biopolymeric Prodrug Systems as Potential Antineoplastic Therapy

Nowadays, cancer represents a major public health issue, a substantial economic issue, and a burden for society. Limited by numerous disadvantages, conventional chemotherapy is being replaced by new strategies targeting tumor cells. In this context, therapies based on biopolymer prodrug systems represent a promising alternative for improving the pharmacokinetic and pharmacologic properties of drugs and reducing their toxicity. The polymer-directed enzyme prodrug therapy is based on tumor cell targeting and release of the drug using polymer–drug and polymer–enzyme conjugates. In addition, current trends are oriented towards natural sources. They are biocompatible, biodegradable, and represent a valuable and renewable source. Therefore, numerous antitumor molecules have been conjugated with natural polymers. The present manuscript highlights the latest research focused on polymer–drug conjugates containing natural polymers such as chitosan, hyaluronic acid, dextran, pullulan, silk fibroin, heparin, and polysaccharides from Auricularia auricula.

Advances in nanoparticle mediated targeting of RNA binding protein for cancer

RNA binding proteins (RBPs) enact a very crucial part in the RNA directive processes. Atypical expression of these RBPs affects many steps of RNA metabolism, majorly altering its expression. Altered expression and dysfunction of RNA binding proteins lead to cancer progression and other diseases. We enumerate various available interventions, and recent findings focused on targeting RBPs for cancer therapy and diagnosis. The treatment, sensitization, chemoprevention, gene-mediated, and virus mediated interventions were studied to treat and diagnose cancer. The application of passively and actively targeted lipidic nanoparticles, polymeric nanoparticles, virus-based particles, and vaccine-based immunotherapy for the delivery of therapeutic agent/s against cancer are discussed. We also discuss the formulation aspect of nanoparticles for achieving delivery at the site of action and ongoing clinical trials targeting RBPs.

Trends and Hotspots in Nanoparticles for the Targeted Delivery of Nucleic Acids: A Ten-Year Bibliometric Study

Nanoparticles for the gene therapy field have seen remarkable progress over the last 10 years; however, low delivery efficiency and other reasons impede the clinical translation of nanocarriers. Therefore, a summary of hotspots and trends in this field is needed to promote further research development. In this research, from 2011 to 2021, 1,221 full records and cited references of Web of Science–indexed manuscripts regarding nanoparticle-targeted delivery systems have been analyzed by CiteSpace, VOSviewer, and MapEquation. In these software, keywords co-occurrence networks, alluvial diagram, co-citation networks, and structural variation analysis were carried out to emphasize the scientific community’s focus on nanomedicine of targeted delivering of nucleic acids. Keywords such as transfection efficiency, tumor cell, membrane antigen, and siRNA delivery were highlighted in the density map from VOSviewer. In addition, an alluvial flow diagram was constructed to detect changes in concepts. In the co-citation network, cluster 1 (exosomes) and cluster 17 (genome editing) were new research fields, and the efforts in modifying nanoparticles were revealed in the structural variation analysis. Aptamer and SELEX (systematic evolution of ligands by exponential enrichment) represented a helpful system in targeted delivery. These results indicated that the transfection efficiency of nanocarriers required continuous improvements. With the approval of several nucleic acid drugs, a new content of nanoparticle carriers is to introduce gene-editing technology, especially CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR–associated protein 9). In addition, exosomes have great potential as targeted nanoparticles. By mapping the knowledge domains of nanomedicine in targeted delivering of nucleic acids, this study analyzed the intellectual structure of this domain in the recent 10 years, highlighting classical modifications on nanoparticles and estimating future trends for researchers and decision-makers interested in this field.

Lactoferrin: A Nutraceutical with Activity against Colorectal Cancer

Homeostasis in the human body results from the tight regulation of several events, since too little inflammation disrupts the process of tissue repair and remodeling, whereas too much exerts a collateral effect by causing tissue damage with life-threatening consequences. In some clinical conditions, such as inflammatory bowel disease (IBD), inflammation functions as a double-edged sword by either enabling or inhibiting cancer development and progression. Generally, cancer develops through evasion mechanisms that regulate cell growth, causing a high rate of uncontrolled proliferation, and mechanisms for evading cell death, such as apoptosis. Moreover, chronic inflammation is a factor that contributes to colorectal cancer (CRC), as observed in individuals with IBD; all these conditions favor an increased rate of angiogenesis and eventual metastasis. Lactoferrin (Lf) is a mammalian iron-binding multifunctional glycoprotein regarded as a natural compound that up- and downregulates both humoral and cellular components of immunity involved in regulating the inflammatory response and maintaining gut homeostasis. Human and bovine Lf share high sequence homology and have very similar antimicrobial, anti-inflammatory, and immunomodulatory activities. Bovine Lf from milk is considered a safe molecule and is commercially available in large quantities. This review mainly focuses on the regulatory effects of orally administered bovine Lf on the inflammatory response associated with CRC; this approach indicates that CRC is one of the most frequently diagnosed cancers and affects the intestinal tract with high clinical and epidemiologic relevance. Thus, this review may provide foundations for the potential use of bovine Lf alone or as a natural adjunct agent to increase the effectiveness and reduce the side effects of anticancer chemotherapy.

Molecular Engineering of Aptamer Self-Assemblies Increases in Vivo Stability and Targeted Recognition

Functionally modified aptamer conjugates are promising tools for targeted imaging or treatment of various diseases. However, broad applications of aptamer molecules are limited by their in vivo instability. To overcome this challenge, current strategies mostly rely on covalent chemical modification of aptamers, a complicated process that requires case-by-case sequence design, multiple-step synthesis, and purification. Herein, we report a covalent modification-free strategy to enhance the in vivo stability of aptamers. This strategy simply utilizes one-step molecular engineering of aptamers with gold nanoclusters (GNCs) to form GNCs@aptamer self-assemblies. Using Sgc8 as a representative aptamer, the resulting GNCs@Sgc8 assemblies enhance cancer-cell-specific binding and sequential internalization by a receptor-mediated endocytosis pathway. Importantly, the GNCs@aptamer self-assemblies resist nuclease degradation for as long as 48 h, compared to the degradation of aptamer alone at 3 h. In parallel, the tumor-targeted recognition and retention of GNCs@aptamer self-assemblies are dramatically enhanced, indicated by a 9-fold signal increase inside the tumor compared to the aptamer alone. This strategy is to avoid complicated chemical modification of aptamers and can be extended to all aptamers. Our work provides a simple, effective, and universal strategy for enhancing the in vivo stability of any aptamer or its conjugates, thus expanding their imaging and therapeutic applications.

Development of Encapsulation Strategies and Composite Edible Films to Maintain Lactoferrin Bioactivity: A Review

Lactoferrin (LF) is a whey protein with various and valuable biological activities. For this reason, LF has been used as a supplement in formula milk and functional products. However, it must be considered that the properties of LF can be affected by technological treatments and gastrointestinal conditions. In this article, we have revised the literature published on the research done during the last decades on the development of various technologies, such as encapsulation or composite materials, to protect LF and avoid its degradation. Multiple compounds can be used to conduct this protective function, such as proteins, including those from milk, or polysaccharides, like alginate or chitosan. Furthermore, LF can be used as a component in complexes, nanoparticles, hydrogels and emulsions, to encapsulate, protect and deliver other bioactive compounds, such as essential oils or probiotics. Additionally, LF can be part of systems to deliver drugs or to apply certain therapies to target cells expressing LF receptors. These systems also allow improving the detection of gliomas and have also been used for treating some pathologies, such as different types of tumours. Finally, the application of LF in edible and active films can be effective against some contaminants and limit the increase of the natural microbiota present in meat, for example, becoming one of the most interesting research topics in food technology.

Chitosan-based nanodelivery systems for cancer therapy: Recent advances

Nowadays, cancer is one of the most prominent issues related to human health since it causes more than one-tenth of death cases throughout the world. On the other hand, routine therapeutic approaches in cancer suppression such as radiation therapy, chemotherapy, surgery, etc. due to their undesirable therapeutic outputs, including low efficiency in cancer inhibition, non-targeted drug delivery, nonselective distribution, and enormous side effects, have been indicated inefficient potency in cancer therapy or at least its growth inhibition. As a result, the development of novel and practical therapeutic methods such as nanoparticle-based drug delivery systems can be outstandingly beneficial in cancer suppression. Among various nanoparticles used in the delivery of bioactive to the tumor site, chitosan (CS) nanoparticles have received high attention. CS, poly [β-(1-4)-linked-2-amino-2-deoxy-d-glucose], is a natural linear amino polysaccharide derived from chitin which is made of irregularly distributed d-glucosamine and N-acetyl-d-glucosamine units. CS nanoparticles owing to their appropriate aspects, including nanometric size, great drug loading efficacy, ease of manipulation, non-toxicity, excellent availability and biocompatibility, good serum stability, long-term circulation time, suitable pharmacokinetic and pharmacodynamics, non-immunogenicity, and enhanced drug solubility in the human body, have been designated as an efficient candidate for drug delivery systems. They can be involved in both passive (based on the enhanced permeability and retention effect cancer targeting) and active (receptor-mediated or stimuli-responsive cancer targeting) drug delivery systems for potential cancer therapy. This review presents the properties, preparation, modification, and numerous pharmaceutical applications of CS-based drug nanodelivery systems in the diagnosis and therapy of cancer.

Nanoparticles as a Tool in Neuro-Oncology Theranostics

The rapid growth of nanotechnology and the development of novel nanomaterials with unique physicochemical characteristics provides potential for the utility of nanomaterials in theranostics, including neuroimaging, for identifying neurodegenerative changes or central nervous system malignancy. Here we present a systematic and thorough review of the current evidence pertaining to the imaging characteristics of various nanomaterials, their associated toxicity profiles, and mechanisms for enhancing tropism in an effort to demonstrate the utility of nanoparticles as an imaging tool in neuro-oncology. Particular attention is given to carbon-based and metal oxide nanoparticles and their theranostic utility in MRI, CT, photoacoustic imaging, PET imaging, fluorescent and NIR fluorescent imaging, and SPECT imaging.

Chitosan nanoparticles as a promising tool in nanomedicine with particular emphasis on oncological treatment

The study describes the current state of knowledge on nanotechnology and its utilization in medicine. The focus in this manuscript was on the properties, usage safety, and potentially valuable applications of chitosan-based nanomaterials. Chitosan nanoparticles have high importance in nanomedicine, biomedical engineering, discovery and development of new drugs. The manuscript reviewed the new studies regarding the use of chitosan-based nanoparticles for creating new release systems with improved bioavailability, increased specificity and sensitivity, and reduced pharmacological toxicity of drugs. Nowadays, effective cancer treatment is a global problem, and recent advances in nanomedicine are of great importance. Special attention was put on the application of chitosan nanoparticles in developing new system for anticancer drug delivery. Pre-clinical and clinical studies support the use of chitosan-based nanoparticles in nanomedicine. This manuscript overviews the last progresses regarding the utilization, stability, and bioavailability of drug nanoencapsulation with chitosan and their safety.

Exploring the room for repurposed hydroxychloroquine to impede COVID-19: toxicities and multipronged combination approaches with pharmaceutical insights

Introduction: SARS-CoV-2 has fatally affected the whole world with millions of deaths. Amidst the dilemma of a breakthrough in vaccine development, hydroxychloroquine (HCQ) was looked upon as a prospective repurposed candidate. It has confronted numerous controversies in the past few months as a chemoprophylactic and treatment option for COVID-19. Recently, it has been withdrawn by the World Health Organization for its use in an ongoing pandemic. However, its benefit/risk ratio regarding its use in COVID-19 disease remains poorly justified. An extensive literature search was done using Scopus, PubMed, Google Scholar, www.cdc.gov, www.fda.gov, and who.int.Areas covered: Toxicity vexations of HCQ; pharmaceutical perspectives on new advances in drug delivery approaches; computational modeling (PBPK and PD modeling) overtures; multipronged combination approaches for enhanced synergism with antiviral and anti-inflammatory agents; immuno-boosting effects.Expert commentary: Harnessing the multipronged pharmaceutical perspectives will optimistically help the researchers, scientists, biotech, and pharmaceutical companies to bring new horizons in the safe and efficacious utilization of HCQ alone or in combination with remdesivir and immunomodulatory molecules like bovine lactoferrin in a fight against COVID-19. Combinational therapies with free forms or nanomedicine based targeted approaches can act synergistically to boost host immunity and stop SARS-CoV-2 replication and invasion to impede the infection.

AS1411-functionalized delivery nanosystems for targeted cancer therapy

Nucleolin (NCL) is a multifunctional nucleolar phosphoprotein harboring critical roles in cells such as cell proliferation, survival, and growth. The dysregulation and overexpression of NCL are related to various pathologic and oncological indications. These characteristics of NCL make it an ideal target for the treatment of various cancers. AS1411 is a synthetic quadruplex-forming nuclease-resistant DNA oligonucleotide aptamer which shows a considerably high affinity for NCL, therefore, being capable of inducing growth inhibition in a variety of tumor cells. The high affinity and specificity of AS1411 towards NCL make it a suitable targeting tool, which can be used for the functionalization of therapeutic payloaddelivery nanosystems to selectively target tumor cells. This review explores the advances in NCL-targeting cancer therapy through AS1411-functionalized delivery nanosystems for the selective delivery of a broad spectrum of therapeutic agents.

Cancer Therapy with Nanoparticle-Medicated Intracellular Expression of Peptide CRM1-Inhibitor

INTRODUCTION

Peptides can be rationally designed as non-covalent inhibitors for molecularly targeted therapy. However, it remains challenging to efficiently deliver the peptides into the targeted cells, which often severely affects their therapeutic efficiency.

METHODS

Herein, we created a novel non-covalent peptide inhibitor against nuclear export factor CRM1 by a structure-guided drug design method and targetedly delivered the peptide into cancer cells by a nanoparticle-mediated gene expression system for use as a cancer therapy.

RESULTS

The nuclear export signal (NES)-optimized CRM1 peptide inhibitor colocalized with CRM1 to the nuclear envelope and inhibited nuclear export in cancer cell lines in vitro. The crystal structures of the inhibitors complexed with CRM1 were solved. In contrast to the covalent inhibitors, the peptides were similarly effective against cells harboring the CRM1 C528S mutation. Moreover, a plasmid encoding the peptides was delivered by a iRGD-modified nanoparticle to efficiently target and transfect the cancer cells in vivo after intravenous administration. The peptides could be selectively expressed in the tumor, resulting in the efficient inhibition of subcutaneous melanoma xenografts without obvious systemic toxicity.

DISCUSSION

This work provides an effective strategy to design peptide-based molecularly targeted therapeutics, which could lead to the development of future targeted therapy.

Effect of Fe₃O₄ Nanomaterial-Based MRI on the Efficacy of One-Sided Butterfly Sinus Lesions in the Nose

Fe₃O₄ materials have many crystal forms, and the morphology of their nanomaterials is more diverse. Under the influence of nano-effects, they exhibit unique physical and chemical properties. The synthesized Fe₃O₄ materials with different morphologies have different properties. They are widely used in related fields such as electromagnetics, chemical engineering, catalysis, sensors, acoustics, medicine, environmental protection and so on. Choosing the appropriate contrast agent to display the anatomical characteristics of diseased and normal tissue is an important thing before using MRI (Magnetic Resonance Imaging) technology. At present, Gd-DTPA is a commonly used magnetic contrast agent in clinical practice, but Gd-DTPA has obvious shortcomings, such as short circulation time, non-specific distribution, and high price. In comparison, the superparamagnetic iron oxide nanocrystals have a high specific distribution in living tissues, mainly concentrated in reticular endothelial cells-rich tissues and organs, such as liver, spleen, lymph nodes and bone marrow. This study analyzed the imaging characteristics of 21 patients with unilateral benign sphenoid sinus disease who were confirmed by nasal endoscopic surgery and postoperative pathology. Among the 21 patients with unilateral benign sphenoid sinus lesions, 7 cases of them had cysts. Those with altered sphenoid sinus cavity expansion may be accompanied by thinning of bone resorption. MRI manifested as long T₁ and long T₂ irregular spherical signal shadows. 8 cases of them are fungal lesions. MRI showed mixed signals are in the sphenoid sinus, the flaky exudation showed a high signal, and the fungal nodule showed a low T₂WI signal. In the 3 cases of cerebrospinal fluid rhinorrhea, MRI showed a line between the high-signal shadow of the cerebrospinal fluid and the high-signal liquid shadow in the sinuses. High signal and shadow are connected, and other tissues (brain tissue, nasal mucosa) show low signal. Fe₃O₄-based MRI technology can improve imaging quality and diagnostic efficiency.

Study of Fe₃O₄-PPy Core-Shell Nanocomposite in the Diagnosis of Tumor Markers in the Tissues of Early Gastric Cancer Patients

In order to study Fe₃O₄-Polypyrrole (Fe₃O₄-PPy) core-shell nanocomposite in the diagnosis of tumor markers in the diseased gastric tissues of early cancer patients, a total of 160 cases of patients, who were confirmed as early gastric cancer by gastroscopy or postoperative pathology at a designated hospital of the study from December 2014 to December 2018, were selected as research objects and were divided into two groups of observation and control group with 80 cases in each group. For each patient in the two groups, two pieces of diseased gastric tissue were firstly taken through gastroscopy; then the observation group applied Fe₃O₄-PPy with the particle diameter of 150-350 nm as carrier to detect the contents of carbohydrate antigen 19-9 (CA19-9), alpha-fetoprotein (AFP), carbohydrate antigen 242 (CA242), carcinoembryonic antigen (CEA) and carbohydrate antigen 72-4 (CA72-4) in the diseased gastric tissue, while the control group directly detected the contents of corresponding tumor markers; after the detections, the sensitivity, specificity and diagnostic efficiency of each marker in the two groups of patients were calculated, and receiver operating characteristics (ROC) curves with the areas under the curves (AUC) were drawn to analyze the correlation between the level of Fe₃O₄-PPy and the detection efficiency of gastric cancer markers. The results show that the detection sensitivity (82.17%, 80.32%, 79.48%, 84.63%, and 85.66%) and specificity (76.75%, 79.66%, 81.07%, 83.47%, and 85.24%) of CA19-9, AFP, CA242, CEA, and CA72-4 in the tumor tissue of patients in observation group for the diagnosis of early gastric cancer are higherthan the sensitivity (78.66%, 79.25%, 76.18%, 82.11%, and 83.45%) and specificity (74.37%, 76.94%, 77.24%, 81.22%, and 81.59%) of that in control group with statistically significant differences (P < 0.05). Therefore, it is believed that the Fe₃O₄-PPy is of great significance for the detection of early gastric tumor markers in the tissues of patients with early gastric cancer, and has certain value for the auxiliary diagnosis of early gastric cancer and the observation of therapeutic effects. This study results provide a reference for the further researches of Fe₃O₄-PPy in the diagnosis of tumor markers in patients with early gastric cancer.

MRI-traceable theranostic nanoparticles for targeted cancer treatment

Current cancer therapies, including chemotherapy and radiotherapy, are imprecise, non-specific, and are often administered at high dosages - resulting in side effects that severely impact the patient's overall well-being. A variety of multifunctional, cancer-targeted nanotheranostic systems that integrate therapy, imaging, and tumor targeting functionalities in a single platform have been developed to overcome the shortcomings of traditional drugs. Among the imaging modalities used, magnetic resonance imaging (MRI) provides high resolution imaging of structures deep within the body and, in combination with other imaging modalities, provides complementary diagnostic information for more accurate identification of tumor characteristics and precise guidance of anti-cancer therapy. This review article presents a comprehensive assessment of nanotheranostic systems that combine MRI-based imaging (T1 MRI, T2 MRI, and multimodal imaging) with therapy (chemo-, thermal-, gene- and combination therapy), connecting a range of topics including hybrid treatment options (e.g. combined chemo-gene therapy), unique MRI-based imaging (e.g. combined T1-T2 imaging, triple and quadruple multimodal imaging), novel targeting strategies (e.g. dual magnetic-active targeting and nanoparticles carrying multiple ligands), and tumor microenvironment-responsive drug release (e.g. redox and pH-responsive nanomaterials). With a special focus on systems that have been tested in vivo, this review is an essential summary of the most advanced developments in this rapidly evolving field.

Nanoparticles as Smart Carriers for Enhanced Cancer Immunotherapy

Cancer immunotherapy has emerged as a promising strategy for the treatment of many forms of cancer by stimulating body's own immune system. This therapy not only eradicates tumor cells by inducing strong anti-tumor immune response but also prevent their recurrence. The clinical cancer immunotherapy faces some insurmountable challenges including high immune-mediated toxicity, lack of effective and targeted delivery of cancer antigens to immune cells and off-target side effects. However, nanotechnology offers some solutions to overcome those limitations, and thus can potentiate the efficacy of immunotherapy. This review focuses on the advancement of nanoparticle-mediated delivery of immunostimulating agents for efficient cancer immunotherapy. Here we have outlined the use of the immunostimulatory nanoparticles as a smart carrier for effective delivery of cancer antigens and adjuvants, type of interactions between nanoparticles and the antigen/adjuvant as well as the factors controlling the interaction between nanoparticles and the receptors on antigen presenting cells. Besides, the role of nanoparticles in targeting/activating immune cells and modulating the immunosuppressive tumor microenvironment has also been discussed extensively. Finally, we have summarized some theranostic applications of the immunomodulatory nanomaterials in treating cancers based on the earlier published reports.

Aptamers in Drug Design: An Emerging Weapon to Fight a Losing Battle

Implementation of novel and biocompatible polymers in drug design is an emerging and rapidly growing area of research. Even though we have a large number of polymer materials for various applications, the biocompatibility of these materials remains as a herculean task for researchers. Aptamers provide a vital and efficient solution to this problem. They are usually small (ranging from 20 to 60 nucleotides, single-stranded DNA or RNA oligonucleotides which are capable of binding to molecules possessing high affinity and other properties like specificity. This review focuses on different aspects of Aptamers in drug discovery, starting from its preparation methods and covering the recent scenario reported in the literature regarding their use in drug discovery. We address the limitations of Aptamers and provide valuable insights into their future potential in the areas regarding drug discovery research. Finally, we explained the major role of Aptamers like medical imaging techniques, application as synthetic antibodies, and the most recent application, which is in combination with nanomedicines.

Lactoferrin, a multi-functional glycoprotein: Active therapeutic, drug nanocarrier & targeting ligand

Recent progress in protein-based nanomedicine, inspired by the success of Abraxane® albumin-paclitaxel nanoparticles, have resulted in novel therapeutics used for treatment of challenging diseases like cancer and viral infections. However, absence of specific drug targeting, poor pharmacokinetics, premature drug release, and off-target toxicity are still formidable challenges in the clinic. Therefore, alternative protein-based nanomedicines were developed to overcome those challenges. In this regard, lactoferrin (Lf), a glycoprotein of transferrin family, offers a promising biodegradable well tolerated material that could be exploited both as an active therapeutic and drug nanocarrier. This review highlights the major pharmacological actions of Lf including anti-cancer, antiviral, and immunomodulatory actions. Delivery technologies of Lf to improve its pries and enhance its efficacy were also reviewed. Moreover, different nano-engineering strategies used for fabrication of drug-loaded Lf nanocarriers were discussed. In addition, the use of Lf for functionalization of drug nanocarriers with emphasis on tumor-targeted drug delivery was illustrated. Besides its wide application in oncology nano-therapeutics, we discussed the recent advances of Lf-based nanocarriers as efficient platforms for delivery of anti-parkinsonian, anti-Alzheimer, anti-viral drugs, immunomodulatory and bone engineering applications.

Targeting cancer with lactoferrin nanoparticles: recent advances

Lactoferrin, an iron storage protein, is known for its microbicidal activity and its ability to modulate the immune system, mediated through specific interactions with receptors on cell surfaces for internalization. These activities confer a significant versatility to lactoferrin, presenting it as a targeting ligand to disease-bearing cells. Early efforts in developing targeted delivery systems have focused on nano- and microcomposites comprised of metal and polymeric materials. These can be targeted through conjugation or adsorption of lactoferrin to achieve recognition to receptor-expressing cells. More recently, efforts are underway to utilize lactoferrin itself as a medium in loading the therapeutic agent. The functional efficiency of drug-loaded lactoferrin nanoparticles has been evaluated in different disease conditions such as cancer, HIV, Parkinson's disease, etc. This review will present the details of composition and performance of various delivery systems designed and developed using lactoferrin as targeting agent for the treatment of cancer.

Effects of chitosan and oligochitosans on the phosphatidylinositol 3-kinase-AKT pathway in cancer therapy

Phosphatidylinositol 3-kinase (PI3K)-AKT pathway is one of the most important kinase signaling networks in the context of cancer development and treatment. Aberrant activation of AKT, the central mediator of this pathway, has been implicated in numerous malignancies including endometrial, hepatocellular, breast, colorectal, prostate, and, cervical cancer. Thus regulation and blockage of this kinase and its key target nodes is an attractive approach in cancer therapy and diverse efforts have been done to achieve this aim. Chitosan is a carbohydrate with multiple interesting applications in cancer diagnosis and treatment strategies. This bioactive polymer and its derivative oligomers commonly used in drug/DNA delivery methods due to their functional properties which improve efficiency of delivery systems. Further, these compounds exert anti-tumor roles through the stimulation of apoptosis, immune enhancing potency, anti-oxidative features and anti-angiogenic roles. Due to the importance of PI3K-AKT signaling in cancer targeting and treatment resistance, this review discusses the involvement of chitosan, oligochitosaccharides and carriers based on these chemicals in the regulation of this pathway in different tumors.

Indium-111-labeled CD166-targeted peptide as a potential nuclear imaging agent for detecting colorectal cancer stem-like cells in a xenograft mouse model

BACKGROUND

Cancer stem cells (CSCs) are involved in drug resistance, metastasis, and relapse of cancers, which can significantly affect tumor therapy. Hence, to develop specifically therapeutic target probe at CSCs for improvement of survival and quality of life of cancer patients is urgently needed. The CD166 protein has been suggested to be involved in colorectal cancer (CRC) tumorigenesis and to be considered a marker for colorectal CSCs (CRCSCs) detection. In this study, therefore, we attend to apply a nuclear imaging agent probe, Glycine₁₈-Cystine-linked CD166-targeted peptides (CD166tp-G₁₈C), to detect the changes of CD166 level in a CRC xenograft mouse model.

RESULTS

We isolated the CD166-positive cells from the HCT15 CRC cell line (CD166⁺HCT15) and evaluated their morphology and ability of clone formation, migration, protein expression, and drug resistance. The CD166-positive HCT15 cells display the CSCs characteristics. We discovered and designed a CD166-targeted peptide (CD166tp-G₁₈C) as a targeted probe of CRC stem-like cell for cell binding assay. The CD166tp-G₁₈C confirmed the CD166 protein targeting ability in CD166⁺HCT15 cells. The diethylenetriaminopentaacetic acid (DTPA)-conjugated CD166tp-G₁₈C further was labeled with indium-111 (¹¹¹In-DTPA-CD166tp-G₁₈C) as nuclear imaging agent for imaging and bio-distribution analysis in vivo. Finally, we observed that the ¹¹¹In-DTPA-CD166tp-G₁₈C was significantly enhanced in tumor tissues of CD166⁺HCT15 xenograft mice as compared to the non-CD166tp-G₁₈C control.

CONCLUSIONS

Our results indicated that the indium-111-labeled CD166tp-G₁₈C may be served as a powerful tool for colorectal CSCs nuclear imaging in the CRC patients.

Calcium phosphate nanocarriers for drug delivery to tumors: imaging, therapy and theranostics

Calcium phosphate (CaP) was engineered as a drug delivery nanocarrier nearly 50 years ago due to its biocompatibility and biodegradability. In recent years, several approaches have been developed for the preparation of size-controllable, stable and multifunctional CaP nanocarriers, and several targeting moieties have also been decorated on the surface of these nanocarriers for active targeting. The CaP nanocarriers have been utilized for loading probes, nucleic acids, anticancer drugs and photosensitizers for cancer imaging, therapy and theranostics. Herein, we reviewed the recent advances in the preparation strategies of CaP nanocarriers and the applications of these nanocarriers in tumor diagnosis, gene delivery, drug delivery and theranostics and finally provided perspectives.

Photonic/magnetic hyperthermia-synergistic nanocatalytic cancer therapy enabled by zero-valence iron nanocatalysts

Traditional cancer-therapeutic modalities such as chemotherapy suffer from the low therapeutic efficiency and severe side effects. The emerging nanocatalytic therapy could in-situ catalyze the endogenous substances into highly toxic species and then efficiently kill the cancer cells, but the lack of high-performance nanocatalysts hinders their broad clinical translation. In this work, we have successfully developed, for the first time, nanosized zero-valence crystalized iron nanoparticles for in-situ triggering nanocatalytic Fenton reaction within tumor microenvironment to produce large amounts of hydroxyl radicals and subsequently kill the cancer cells, which could be further synergistically enhanced by either photonic hyperthermia or magnetic hyperthermia as assisted by these iron nanoparticles acting as photothermal-conversion or magnetothermal-conversion nanoagents, respectively. Especially, the excellent magnetic performance of these zero-valence crystallized iron nanoparticles has achieved both in vitro and in vivo contrast-enhance magnetic resonance imaging for potentially guiding the photonic/magnetic hyperthermia-synergistic nanocatalytic cancer therapy. This work not only provides the new type of iron-based nanoparticles for biomedical application, but also demonstrates the high efficiency of nanocatalytic cancer therapy as assisted by both photonic and magnetic hyperthermia.

Molecular Engineering of Functional Nucleic Acid Nanomaterials toward In Vivo Applications

Recent advances in nanotechnology and engineering have generated many nanomaterials with unique physical and chemical properties. Over the past decade, numerous nanomaterials are introduced into many research areas, such as sensors for environmental monitoring, food safety, point-of-care diagnostics, and as transducers for solar energy transfer. Meanwhile, functional nucleic acids (FNAs), including nucleic acid enzymes, aptamers, and aptazymes, have attracted major attention from the biomedical community due to their unique target recognition and catalytic properties. Benefiting from the recent progress of molecular engineering strategies, the physicochemical properties of nanomaterials are endowed by the target recognition and catalytic activity of FNAs in the presence of a target analyte, resulting in numerous smart nanoprobes for diverse applications including intracellular imaging, drug delivery, in vivo imaging, and tumor therapy. This progress report focuses on the recent advances in designing and engineering FNA-based nanomaterials, highlighting the functional outcomes toward in vivo applications. The challenges and opportunities for the future translation of FNA-based nanomaterials into clinical applications are also discussed.

Colorimetric Aptasensor Based on Truncated Aptamer and Trivalent DNAzyme for Vibrio parahemolyticus Determination

In this work, after optimizing the original aptamer sequence by truncation and site-directed mutagenesis, a simple and sensitive colorimetric aptasensor was established for detecting the widespread food-borne pathogen Vibrio parahemolyticus ( V. parahemolyticus). The detection strategy was based on the competition for an V. parahemolyticus specific aptamer between its complementary DNA (cDNA) and V. parahemolyticus. The aptamer-conjugated magnetic nanoparticles (MNPs) were used as capture probes, and the G-quadruplex (G4) DNAzyme was employed as the signal amplifying element. Under optimal conditions, a wide linear detection range (from 10² to 10⁷ cfu/mL) was available, and the detection limit could be as low as 10 cfu/mL. This method was also used to detect V. parahemolyticus in contaminated salmon samples, and the results showed good consistency with those obtained from standard plate counting method. Therefore, this novel aptasensor could be a good candidate for sensitive and selective detection of V. parahemolyticus without complicated operations.

Holo-Lactoferrin Modified Liposome for Relieving Tumor Hypoxia and Enhancing Radiochemotherapy of Cancer

Hypoxic microenvironments in the solid tumor play a negative role in radiotherapy. Holo-lactoferrin (holo-Lf) is a natural protein, which acts as a potential ligand of transferrin receptor (TfR). In this work, an anticancer drug, doxorubicin (Dox)-loaded liposome-holo-Lf nanocomposites, is developed for tumor targeting and imaging guided combined radiochemotherapy. Dox-loaded liposome-holo-Lf (Lf-Liposome-Dox) nanocomposites exhibit significant cellular uptake likely owing to the TfR receptor-mediated targeting accumulation of Lf-Liposome-Dox nanocomposites. Additionally, the nanocomposites exhibit high accumulation in the tumor site after intravenous injection as evidenced from in vivo fluorescence imaging. More importantly, it is found that the holo-Lf has the ability to catalyze the conversion of hydrogen peroxide (H₂ O₂ ) to oxygen for relieving the tumor hypoxic microenvironment. Photoacoustic imaging further confirms the abundant generation of oxygen in the presence of Lf-Liposome-Dox nanocomposites. Based on these findings, in vivo combined radiochemotherapy is performed using Lf-Liposome-Dox as therapeutic agent, achieving excellent cancer treatment effect. The study further promotes the potential biomedical application of holo-Lf in cancer treatment.

A multifunctional biomimetic hybrid nanocarrier for the controlled delivery of chemotherapy drugs by near-infrared light

We have constructed a biocompatible magnetic nanoparticle-based nanocomposite material by integrating the features of Fe₃O₄ nanoparticles, mesoporous silica and lipid bilayer for the treatment of tumor.

Phosphorothioate-Modified AP613-1 Specifically Targets GPC3 when Used for Hepatocellular Carcinoma Cell Imaging

Glypican-3 (GPC3), the cellular membrane proteoglycan, has been established as a tumor biomarker for early diagnosis of hepatocellular carcinoma (HCC). GPC3 is highly expressed in more than 70% HCC tissues detected by antibody-based histopathological systems. Recently, aptamers, a short single-strand DNA or RNA generated from systematic evolution of ligands by exponential enrichment (SELEX), were reported as potential alternatives in tumor-targeted imaging and diagnosis. In this study, a total of 19 GPC3-bound aptamers were successfully screened by capillary electrophoresis (CE)-SELEX technology. After truncated, AP613-1 was confirmed to specifically target GPC3 with a dissociation constant (K_D) of 59.85 nM. When modified with a phosphorothioate linkage, APS613-1 targeted GPC3 with a K_D of 15.48 nM and could be used as a specific probe in living Huh7 and PLC/PRF/5 imaging, GPC3-positive cell lines, but not in L02 or A549, two GPC3-negative cell lines. More importantly, Alexa Fluor 750-conjugated APS613-1 could be used as a fluorescent probe to subcutaneous HCC imaging in xenograft nude mice. Our results indicated that modified AP613-1, especially APS613-1, was a potential agent in GPC3-positive tumor imaging for HCC early diagnosis.

Nucleic acid aptamers in diagnosis of colorectal cancer

Nucleic acid aptamers are promising recognition ligands for diagnostic applications. They are short DNA or RNA molecules isolated from large random libraries through the Systematic Evolution of Ligands by EXponential enrichment (SELEX) procedure. These molecules, with a particular three-dimensional shape, bind to a wide range of targets from small molecules to whole cells with high affinity and specificity. The unique properties of nucleic acid aptamers including high binding affinity and specificity, thermostability, ease of chemical production, ease of chemical modification, target adaptability, simple storage, resistance to denaturation, low immunogenicity, and low cost make them potential diagnostic tools for clinical use. Colorectal cancer is one of the most common types of cancer in humans and the third leading cause of cancer deaths in the world. Due to low response rate to current therapies in advanced stages of the disease, early detection of CRC can be useful in disease management. This review highlights recent advances in the development of nucleic acid aptamer-based methods for diagnosis, prognosis, and theranosis of colorectal cancer.

Aptamer-based targeted therapy

Precision medicine holds great promise to harness genetic and epigenetic cues for targeted treatment of a variety of diseases, ranging from many types of cancers, neurodegenerative diseases, to cardiovascular diseases. The proteomic profiles resulting from the unique genetic and epigenetic signatures represent a class of relatively well accessible molecular targets for both interrogation (e.g., diagnosis, prognosis) and intervention (e.g., targeted therapy) of these diseases. Aptamers are promising for such applications by specific binding with cognate disease biomarkers. Nucleic acid aptamers are a class of DNA or RNA with unique three-dimensional conformations that allow them to specifically bind with target molecules. Aptamers can be relatively easily screened, reproducibly manufactured, programmably designed, and chemically modified for various biomedical applications, including targeted therapy. Aptamers can be chemically modified to resist enzymatic degradation or optimize their pharmacological behaviors, which ensured their chemical integrity and bioavailability under physiological conditions. In this review, we will focus on recent progress and discuss the challenges and opportunities in the research areas of aptamer-based targeted therapy in the forms of aptamer therapeutics and aptamer-drug conjugates (ApDCs).

Application of aptamers for in vivo molecular imaging and theranostics

Nucleic acid aptamers are small three-dimensional structures of oligonucleotides selected to bind to a target of interest with high affinity and specificity. In vitro, aptamers already compete with antibodies to serve as imaging probes, e.g. for microscopy or flow cytometry. However, they are also increasingly used for in vivo molecular imaging. Accordingly, aptamers have been evaluated over the last twenty years in almost every imaging modality, including single photon emission computed tomography, positron emission tomography, magnetic resonance imaging, fluorescence imaging, echography, and x-ray computed tomography. This review focuses on the studies that were conducted in vivo with aptamer-based imaging probes. It also presents how aptamers have been recently used to develop new types of probes for multimodal imaging and theranostic applications.

AS1411-decorated niosomes as effective nanocarriers for Ru(iii)-based drugs in anticancer strategies

Niosomes are self-assembled vesicles made up of single chain non-ionic surfactants combined with appropriate amounts of cholesterol or other lipids, exploited as carriers for hydrophilic or lipophilic drugs. Compared to liposomes, niosomes are typically more stable, less expensive and, being generally obtained from synthetic surfactants, more easily derivatizable, providing vesicular structures with a higher versatility and chemical diversity. Herein, we investigated the physico-chemical and biological properties of niosomes loaded with two active ingredients, i.e. the nucleolipidic Ru(iii)-complex HoThyRu, selected as an anticancer agent, and the nucleolin-targeting AS1411 aptamer, allowing selective recognition of cancer cells. The morphology, average size, zeta potential, electrophoretic mobility, and stability over time of the functionalized niosomes were analyzed using different biophysical techniques. These formulations, tested on both cancer and normal cells, showed promising antiproliferative activity on HeLa cells, with a higher efficacy associated with the nanosystems containing both AS1411 and HoThyRu with respect to the controls. In all the tested cell lines, AS1411 proved to markedly enhance the bioactivity of the Ru(iii)-containing niosomes.

A GPC3-specific aptamer-mediated magnetic resonance probe for hepatocellular carcinoma

Purpose

To construct and test a hepatocellular carcinoma (HCC)-targeted magnetic resonance probe based on a glypican-3 (GPC3)-specific aptamer (AP613-1) with ultrasmall superpara-magnetic iron oxide (USPIO).

Methods

Oleic acid-coated USPIO nanoparticles were modified with amino polyethylene glycol on the surface. Amino groups of the USPIO nanoparticles were reacted with the carboxyl group of 5' carboxyl-modified AP613-1, forming an aptamer-mediated USPIO (Apt-USPIO) probe. The material characterization of this probe including transmission electron microscopy (TEM), zeta potential, dynamic laser scattering, and magnetic behavior was carried out. The targeting efficiency and magnetic resonance imaging (MRI) performance of Apt-USPIO were evaluated both in vitro and in vivo with USPIO alone as a control. The cytotoxicity and bio-compatibility of Apt-USPIO and USPIO were analyzed by cell counting kit-8 tests in vitro and animal experiments in vivo.

Results

TEM imaging revealed that the Apt-USPIO nanoparticles were spherical in shape and well dispersed. Specific uptake of Apt-USPIO in Huh-7 cells could be observed using the Prussian blue staining test; however, no uptake of USPIO could be found. In vitro phantom T₂-weighted MRI showed a significant decrease of the signal intensity in Apt-USPIO-incubated Huh-7 cells compared to USPIO-incubated Huh-7 cells. In vivo T₂-weighted MRI showed significantly negative enhancement in the Huh-7 tumors enhanced with Apt-USPIO, whereas no enhancement was found with USPIO alone. Excellent biocompatibility of Apt-USPIO and USPIO was also demonstrated.

Conclusion

In this study, a molecular MRI probe which was highly specific to GPC3 on HCC was successfully prepared. Our results validated the targeted imaging effect of this Apt-USPIO probe in vivo for GPC3-expressing HCCs in xenograft mice.

Targeted Molecular Imaging Using Aptamers in Cancer

Imaging is not only seeing, but also believing. For targeted imaging modalities, nucleic acid aptamers have features such as superior recognition of structural epitopes and quick uptake in target cells. This explains the emergence of an evolved new class of aptamers into a wide spectrum of imaging applications over the last decade. Genetically encoded biosensors tagged with fluorescent RNA aptamers have been developed as intracellular imaging tools to understand cellular signaling and physiology in live cells. Cancer-specific aptamers labeled with fluorescence have been used for assessment of clinical tissue specimens. Aptamers conjugated with gold nanoparticles have been employed to develop innovative mass spectrometry tissue imaging. Also, use of chemically conjugated cancer-specific aptamers as probes for non-invasive and high-resolution imaging has been transformative for in vivo imaging in multiple cancers.

Molecular Cancer Imaging in the Second Near-Infrared Window Using a Renal-Excreted NIR-II Fluorophore-Peptide Probe

In vivo molecular imaging of tumors targeting a specific cancer cell marker is a promising strategy for cancer diagnosis and imaging guided surgery and therapy. While targeted imaging often relies on antibody-modified probes, peptides can afford targeting probes with small sizes, high penetrating ability, and rapid excretion. Recently, in vivo fluorescence imaging in the second near-infrared window (NIR-II, 1000-1700 nm) shows promise in reaching sub-centimeter depth with microscale resolution. Here, a novel peptide (named CP) conjugated NIR-II fluorescent probe is reported for molecular tumor imaging targeting a tumor stem cell biomarker CD133. The click chemistry derived peptide-dye (CP-IRT dye) probe afforded efficient in vivo tumor targeting in mice with a high tumor-to-normal tissue signal ratio (T/NT > 8). Importantly, the CP-IRT probes are rapidly renal excreted (≈87% excretion within 6 h), in stark contrast to accumulation in the liver for typical antibody-dye probes. Further, with NIR-II emitting CP-IRT probes, urethra of mice can be imaged fluorescently for the first time noninvasively through intact tissue. The NIR-II fluorescent, CD133 targeting imaging probes are potentially useful for human use in the clinic for cancer diagnosis and therapy.

In vivo fluorescence imaging of hepatocellular carcinoma using a novel GPC3-specific aptamer probe

Background

Glypican-3 (GPC3) is highly expressed in most of the hepatocellular carcinomas (HCCs), even in small HCCs. It may be used as a potential biomarker for early detection of HCC. The aptamer is a promising targeting agent with unique advantages over antibody. This study was to introduce a novel GPC3 specific aptamer (AP613-1), to verify its specific binding property in vitro, and to evaluate its targeting efficiency in vivo by performing near-infrared (NIR) fluorescence imaging on an HCC xenograft model.

Methods

AP613-1 was generated from the systematic evolution of ligands by exponential enrichment. Flow cytometry and aptamer-based immunofluorescence imaging were performed to verify the binding affinity of AP613-1 to GPC3 in vitro. NIR Fluorescence images of nude mice with unilateral (n=12) and bilateral (n=4) subcutaneous xenograft tumors were obtained. Correlation between the tumor fluorescence intensities in vivo and ex vivo was analyzed.

Results

AP613-1 could specifically bind to GPC3 in vitro. In vivo and ex vivo tumors, fluorescence intensities were in excellent correlation (P<0.001, r=0.968). The fluorescence intensity is significantly higher in tumors given Alexa Fluor 750 (AF750) labeled AP613-1 than in those given AF750 labeled initial ssDNA library both in vivo (P<0.001) and ex vivo (P=0.022). In the mice with bilateral subcutaneous tumors injected with AF750 labeled AP613-1, Huh-7 tumors showed significantly higher fluorescence intensities than A549 tumors both in vivo (P=0.016) and ex vivo (P=0.004).

Conclusions

AP613-1 displays a specific binding affinity to GPC3 positive HCC. Fluorescently labeled AP613-1 could be used as an imaging probe to subcutaneous HCC in xenograft models.

Recent advances in aptamer-armed multimodal theranostic nanosystems for imaging and targeted therapy of cancer

The side effects of chemotherapeutics during the course of cancer treatment limit their clinical outcomes. The most important mission of the modern cancer therapy modalities is the delivery of anticancer drugs specifically to the target cells/tissue in order to avoid/reduce any inadvertent non-specific impacts on the healthy normal cells. Nanocarriers decorated with a designated targeting ligand such as aptamers (Aps) and antibodies (Abs) are able to deliver cargo molecules to the target cells/tissue without affecting other neighboring cells, resulting in an improved treatment of cancer. For targeted therapy of cancer, different ligands (e.g., protein, peptide, Abs, Aps and small molecules) have widely been used in the development of different targeting drug delivery systems (DDSs). Of these homing agents, nucleic acid Aps show unique targeting potential with high binding affinity to a variety of biological targets (e.g., genes, peptides, proteins, and even cells and organs). Aps have widely been used as the targeting agent, in large part due to their unique 3D structure, simplicity in synthesis and functionalization, high chemical flexibility, low immunogenicity and toxicity, and cell/tissue penetration capability in some cases. Here, in this review, we provide important insights on Ap-decorated multimodal nanosystems (NSs) and discuss their applications in targeted therapy and imaging of cancer.

Calcium-based biomaterials for diagnosis, treatment, and theranostics

Calcium-based biomaterials with good biosafety and bio-absorbability are promising for biomedical applications such as diagnosis, treatment, and theranostics.

The diagnosis of hepatic fibrosis by magnetic resonance and near-infrared imaging using dual-modality nanoparticles

Hepatic fibrosis (HF), as the only reversible process of chronic liver disease, remains a big diagnostic challenge. Development of noninvasive and effective methods to assess quantitatively early-stage HF is of great clinical importance. Compared with conventional diagnostic methods, near-infrared fluorescence imaging (NIR) and magnetic resonance imaging (MRI) could offer highly sensitive and spatial resolution signals for HF detection. However, precise detection using contrast agents is not possible. Superparamagnetic iron oxide (SPIO) nanoparticles have low toxicity, high sensitivity and excellent biocompatibility. Integration of Fe₃O₄ nanoparticles and indocyanine green (ICG), coupled with targeting ligand of integrin α_vβ₃, arginine–glycine–aspartic acid (RGD) expressed on hepatic stellate cells (HSCs), were used to detect HF. Both in vivo and in vitro results showed that the SPIO@SiO₂–ICG–RGD had high stability and low cytotoxicity. The biodistribution of SPIO@SiO₂–ICG–RGD was significantly different between mice with HF and healthy controls. SPIO@SiO₂–ICG–RGD was characterized and the results of imaging in vitro and in vivo demonstrated the expression of integrin α_vβ₃ on activated HSCs. These data suggest that our SPIO@SiO₂–ICG–RGD probe could be used for the diagnosis of early-stage HF. This new nanoprobe with a dual-modality imaging approach holds great potential for the diagnosis and classification of HF.

Schematic diagram for the synthesis of SPIO@SiO₂–ICG–RGD.

Aptamer-Based Therapeutic Approaches to Target Cancer Stem Cells

Cancer stem cells (CSCs) are believed to be a principal cellular source for tumour progression and therapeutic drug resistance as they are capable of self-renewal and can differentiate into cancer cells. Importantly, CSCs acquire the ability to evade the killing effects of cytotoxic agents through changes at the genetic, epigenetic and micro-environment levels. Therefore, therapeutic strategies targeting CSCs hold great potential as an avenue for cancer treatment. Aptamers or "chemical antibodies" are a group of single-stranded nucleic acid (DNA or RNA) oligonucleotides with distinctive properties such as smaller size, lower toxicity and less immunogenicity compared to conventional antibodies. They have been frequently used to deliver therapeutic payloads to cancer cells and have achieved encouraging anti-tumour effects. This review discusses progress in CSC evolution theory and the role of aptamers to target CSCs for cancer treatment. Challenges of aptamer-mediated CSC targeting approaches are also discussed.

Controllable synthesis Fe3O4@POHABA core-shell nanostructure as high-performance recyclable bifunctional magnetic antimicrobial agent

We demonstrated a method to form magnetic antimicrobial POHABA (poly-N,N'-[(4,5-dihydroxy-1,2-phenylene)bis(methylene)]bisacrylamide)-based core-shell nanostructure by free-radical polymerization of OHABA on the Fe₃O₄ core surface. The magnetic antimicrobial agent Fe₃O₄@POHABA can be used in domestic water treatment against bacterial pathogens. The thickness of POHABA shell could be controlled from 10.4 ± 1.2 to 56.3 ± 11.7 nm by the dosage of OHABA. The results of antimicrobial-activity test indicated that POHABA-based core-shell nanostructure had broad-spectrum inhibitory against Gram-negative, Gram-positive bacteria and fungi. The minimum inhibitory concentration (MIC) values of Fe₃O₄@POHABA nanostructure against Escherichia coli and Bacillus subtilis were both 0.4 mg/mL. Fe₃O₄@POHABA nanostructures responded to a permanent magnet and were easily recycled. Fe₃O₄@POHABA nanoparticles retained 100% antimicrobial efficiency for both Gram-negative and Gram-positive bacteria throughout eight recycle procedures.

Fabrication and Cytotoxicity of Gemcitabine-Functionalized Magnetite Nanoparticles

Nanotechnology has been successfully used for the fabrication of targeted anti-cancer drug carriers. This study aimed to obtain Fe₃O₄ nanoparticles functionalized with Gemcitabine to improve the cytotoxic effects of the chemotherapeutic substance on cancer cells. The (un) functionalized magnetite nanoparticles were synthesized using a modified co-precipitation method. The nanoconjugate characterization was performed by XRD, SEM, SAED and HRTEM; the functionalizing of magnetite with anti-tumor substances has been highlighted through TGA. The interaction with biologic media has been studied by means of stability and agglomeration tendency (using DLS and Zeta Potential); also, the release kinetics of the drug in culture media was evaluated. Cytotoxicity of free-Gemcitabine and the obtained nanoconjugate were evaluated on human BT 474 breast ductal carcinoma, HepG2 hepatocellular carcinoma and MG 63 osteosarcoma cells by MTS. In parallel, cellular morphology of these cells were examined through fluorescence microscopy and SEM. The localization of the nanoparticles related to the cells was studied using SEM, EDX and TEM. Hemolysis assay showed no damage of erythrocytes. Additionally, an in vivo biodistribution study was made for tracking where Fe₃O₄@Gemcitabine traveled in the body of mice. Our results showed that the transport of the drug improves the cytotoxic effects in comparison with the one produced by free Gemcitabine for the BT474 and HepG2 cells. The in vivo biodistribution test proved nanoparticle accumulation in the vital organs, with the exception of spleen, where black-brown deposits have been found. These results indicate that our Gemcitabine-functionalized nanoparticles are a promising targeted system for applications in cancer therapy.