In vitro and in vivo evaluation of anti-nucleolin-targeted magnetic PLGA nanoparticles loaded with doxorubicin as a theranostic agent for enhanced targeted cancer imaging and therapy

Targeted delivery of elesclomol using a magnetic mesoporous platform improves prostate cancer treatment both in vitro and in vivo

BACKGROUND

To improve the anticancer properties of elesclomol (ELC), targeted theranostic nanoparticles (NPs; APT-PEG-Au-MMNPs@ELC) were designed to increase the selectivity of the drug delivery system (DDS).

MATERIALS AND METHODS

ELC was synthesized and entrapped in the open porous structure of magnetic mesoporous silica nanoparticles (MMNPs). The pore entrance of MMNPs was then blocked using gold gatekeepers. Finally, the external surfaces of the particles were grafted with functional polyethylene glycol (PEG) and EpCAM aptamer to generate biocompatible and targeted NPs. In the next step, the physicochemical properties of prepared NPs were fully evaluated and their anticancer potential was evaluated both in vitro and in vivo.

RESULTS

The targeted NPs were successfully synthesized with a final size diameter of 81.13 ± 7.41 nm. The results indicated a pH-dependent release pattern, which sustained for 72 h despite an initial rapid release. Upon exposure to APT-PEG-Au-MMNPs@ELC, higher cytotoxicity was observed in human prostate cancer cells (PC-3) as compared with control Chinese hamster ovary (CHO) cells, indicating higher specificity of targeted NPs against EpCAM-positive cancerous cells. Moreover, APT-PEG-Au-MMNPs@ELC could induce apoptosis in PC-3 cells. In vivo results on a PC-3 xenograft tumor model demonstrated that targeted NPs could significantly inhibit tumor growth and diminish severe side effects of ELC, compared to the free drug.

CONCLUSION

Collectively, APT-PEG-Au-MMNPs@ELC could be considered a promising theranostic platform for the targeted delivery of ELC to improve its therapeutic effects in prostate cancer.

Enhanced theranostic efficacy of epirubicin-loaded SPION@MSN through co-delivery of an anti-miR-21-expressing plasmid and ZIF-8 hybridization to target colon adenocarcinoma

Using targeted drug delivery systems has emerged as a promising approach to increase the efficacy of chemotherapy, particularly in combination with gene therapy. The overexpression of miR-21 plays a crucial role in colorectal cancer (CRC) progression, and targeted inhibition of miR-21 offers significant potential for enhancing CRC chemotherapy outcomes. In this study, a theranostic system based on mesoporous silica and superparamagnetic iron oxide nanoparticles (SPION@MSNs) was synthesized as a core-shell structure. After loading epirubicin (EPI) in the open pores of MSN, the plasmid expressing anti-miR-21 (pDNA) covered the outer surface with the help of a ZIF-8 (zeolitic imidazolate framework-8) film. Afterward, polyethylene glycol (PEG) and AS1411 aptamer were conjugated to the surface to improve the protective, biocompatibility, and targeting abilities of the nanocarrier. Moreover, the physicochemical characteristics as well as the loading capacity and release profile of EPI and pDNA were fully evaluated. The uptake of the nanoparticles by CRC and normal cell lines in addition to the anticancer effects related to targeted combinational therapy were investigated in vitro. Finally, in vivo tests were performed on BALB/c mice bearing colorectal tumors to evaluate the effectiveness of the targeted nanoparticles, their possible side effects, and also their application in fluorescence and magnetic imaging in vivo. The successful synthesis of SPION@MSN-EPI/pDNA-ZIF-8-PEG-Apt nanoparticles (∼68 nm) and good loading efficiency and controlled release of EPI and pDNA were confirmed. Moreover, hemolysis and gel retardation assays demonstrated the biocompatibility and plasmid protection. Cellular uptake and expression of copGFP illustrated selective entry and transient transfection of targeted nanoparticles, consistent with the cytotoxicity results that indicated the synergistic effects of chemo-gene therapy. The results of animal studies proved the high antitumor efficiency of targeted nanoparticles with minimal tissue damage, which was in line with fluorescence and magnetic imaging results. The novel synthesized nanoparticles containing SPION@MSN-ZIF-8 were suitable for CRC theranostics, and the combined approach of chemo-gene therapy suppressed the tumor more effectively.

Contrasting Properties of Polymeric Nanocarriers for MRI-Guided Drug Delivery

Poor pharmacokinetics and low aqueous solubility combined with rapid clearance from the circulation of drugs result in their limited effectiveness and generally high therapeutic doses. The use of nanocarriers for drug delivery can prevent the rapid degradation of the drug, leading to its increased half-life. It can also improve the solubility and stability of drugs, advance their distribution and targeting, ensure a sustained release, and reduce drug resistance by delivering multiple therapeutic agents simultaneously. Furthermore, nanotechnology enables the combination of therapeutics with biomedical imaging agents and other treatment modalities to overcome the challenges of disease diagnosis and therapy. Such an approach is referred to as "theranostics" and aims to offer a more patient-specific approach through the observation of the distribution of contrast agents that are linked to therapeutics. The purpose of this paper is to present the recent scientific reports on polymeric nanocarriers for MRI-guided drug delivery. Polymeric nanocarriers are a very broad and versatile group of materials for drug delivery, providing high loading capacities, improved pharmacokinetics, and biocompatibility. The main focus was on the contrasting properties of proposed polymeric nanocarriers, which can be categorized into three main groups: polymeric nanocarriers (1) with relaxation-type contrast agents, (2) with chemical exchange saturation transfer (CEST) properties, and (3) with direct detection contrast agents based on fluorinated compounds. The importance of this aspect tends to be downplayed, despite its being essential for the successful design of applicable theranostic nanocarriers for image-guided drug delivery. If available, cytotoxicity and therapeutic effects were also summarized.

Synthesis, Characterization, and Biological Evaluation of Radiolabeled Glutamine Conjugated Polymeric Nanoparticles: A Simple Approach for Tumor Imaging

Application of nanoradiopharmaceuticals for molecular imaging has gained worldwide importance for their multifaceted potentials focusing on providing a safe and cost-effective approach. Biodistribution studies on such species are capable of bringing nanomedicine to patients. Current therapeutically available labeling strategies suffer from different limitations, including off-target cytotoxicity and radiolabel release over time. Poly(lactic-co-glycolic acid)(PLGA) nanoparticles are biodegradable carriers for a variety of contrast agents that can be employed in medicine with high loading capacity for multimodal imaging agents. Here, glutamine-conjugated PLGA polymers were used to construct polymeric nanoparticles (G-PNP) similar to unconjugated PLGA nanoparticles (PNP)s formulated for ex vivo cell labeling and in vivo tumor scintigraphy studies. G-PNP/PNP, characterized by Fourier-transform infrared, atomic-force-microscopy, particle-size, and zeta-potential studies, were biocompatible as evaluated by MTT assay. G-PNPs were radiolabeled with ^99mtechnetium (^99mTc) by borohydrite reduction. G-PNPs demonstrated higher cellular uptake than PNPs, with no major cytotoxicity. Radiochemical purity indicated that ^99mTc labeled G-PNP (^99mTc-G-PNP) can form a stable complex with substantial stability in serum with respect to time. Imaging studies showed that ^99mTc-G-PNP significantly accumulated at the C6 glioma cell induced tumor-site in rats. Thus, ^99mTc-G-PNP demonstrated favorable characteristics and imaging potential which may make it a promising tumor imaging nanoprobe as a nanoradiopharmaceutical.

Clindamycin phosphate and bone morphogenetic protein-7 loaded combined nanoparticle-graft and nanoparticle-film formulations for alveolar bone regeneration - An in vitro and in vivo evaluation

Commonly utilized techniques for healing alveolar bone destruction such as the use of growth factors, suffering from short half-life, application difficulties, and the ability to achieve bioactivity only in the presence of high doses of growth factor. The sustained release of growth factors through a scaffold-based delivery system offers a promising and innovative tool in dentistry. Furthermore, it is suggested to guide the host response by using antimicrobials together with growth factors to prevent recovery and achieve ideal regeneration. Herein, the aim was to prepare and an in vitro - in vivo evaluation of bone morphogenetic protein 7 (BMP-7) and clindamycin phosphate (CDP) loaded polymeric nanoparticles, and their loading into the alginate-chitosan polyelectrolyte complex film or alloplastic graft to accelerate hard tissue regeneration. PLGA nanoparticles containing CDP and BMP-7, separately or together, were prepared using the double emulsion solvent evaporation technique. Through in vitro assays, it was revealed that spherical particles were homogeneously distributed in the combination formulations, and sustained release could be achieved for >12 weeks with all formulations. Also, results from the micro-CT and histopathological analyses indicated that CDP and BMP-7 loaded nanoparticle-film formulations were more effective in treatment than the nanoparticle loaded grafts.

Biomedical applications of aptamer-modified chitosan nanomaterials: An updated review

Among polysaccharides of environmental and economic interest, chitosan (CS) is receiving much attention, particularly in the food and biotechnology industries to encapsulate active food ingredients and immobilize enzymes. CS nanoparticles (CS NPs) combine the intrinsic beneficial properties of both natural polymers and nanoscale particles such as quantum size effect, biocompatibility, biodegradability, and ease of modification, and have great potential for bioimaging, drug delivery, and biosensing applications. Aptamers are single-stranded oligonucleotides that can fold into predetermined structures and bind to the corresponding biomolecules. They are mainly used as targeting ligands in biosensors, disease diagnostic kits and treatment strategies. They can deliver contrast agents and drugs into cancer cells and tissues, control microorganism growth and precisely target pathogens. Aptamer-conjugated CS NPs can significantly improve the efficacy of conventional therapies, minimize their side effects on normal tissues, and overcome the enhanced permeability retention (EPR) effect. Further, aptamer-conjugated carbohydrate-based nanobiopolymers have shown excellent antibacterial and antiviral properties and can be used to develop novel biosensors for the efficient detection of antibiotics, toxins, and other biomolecules. This updated review aims to provide a comprehensive overview of the bioapplications of aptamer-conjugated CS NPs used as innovative diagnostic and therapeutic platforms, their limitations, and potential future directions.

Nanoconstructs for theranostic application in cancer: Challenges and strategies to enhance the delivery

Nanoconstructs are made up of nanoparticles and ligands, which can deliver the loaded cargo at the desired site of action. Various nanoparticulate platforms have been utilized for the preparation of nanoconstructs, which may serve both diagnostic as well as therapeutic purposes. Nanoconstructs are mostly used to overcome the limitations of cancer therapies, such as toxicity, nonspecific distribution of the drug, and uncontrolled release rate. The strategies employed during the design of nanoconstructs help improve the efficiency and specificity of loaded theranostic agents and make them a successful approach for cancer therapy. Nanoconstructs are designed with a sole purpose of targeting the requisite site, overcoming the barriers which hinders its right placement for desired benefit. Therefore, instead of classifying modes for delivery of nanoconstructs as actively or passively targeted systems, they are suitably classified as autonomous and nonautonomous types. At large, nanoconstructs offer numerous benefits, however they suffer from multiple challenges, too. Hence, to overcome such challenges computational modelling methods and artificial intelligence/machine learning processes are being explored. The current review provides an overview on attributes and applications offered by nanoconstructs as theranostic agent in cancer.

Application of aptamer functionalized nanomaterials in targeting therapeutics of typical tumors

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

Anti-nucleolin Aptamer as a Boom in Rehabilitation of Breast Cancer

Breast cancer is the second leading cause of cancer-related deaths. It is important to target the complex pathways using a suitable targeted delivery system. Targeted delivery systems can effectively act on cancer cells and lead to the annihilation of tumor proliferation. They mainly employ targeting agents like aptamers linked to the formulation. Based on the expression of the receptors on the surface of the cancer cells, suitable aptamers can be developed. AS1411 is one such aptamer that has the ability to bind to the over-expressed nucleolin present in breast cancer cells. Nucleolin is a phosphoprotein that is involved in various aspects, like cell growth, differentiation and survival. Mostly they are found in the nucleolus, nucleus, cytoplasm and cell surface. The shuttling effect of the nucleolin between the nucleus and cytoplasm serves as a bonus for the AS1411 aptamer. Because of the shutting effect, the internalization of the drug compound or chemotherapeutic drug inside the cell can be achieved. In this article, we have discussed nucleolin, anti-nucleolin aptamer, namely, AS1411, and its application in exhibiting various anticancer activities, including apoptosis, anti-angiogenesis, anti-metastasis, stimulation of tumor suppressor (i.e., P53), and inhibition of tumor inducer. Further, the ways of internalization, namely macropinocytosis, are also discussed. Additionally, we have also discussed the superiority of the aptamer compared to the antibodies as well as the limitations of the aptamers. By considering all the above parameters, we hope this aptamer will be effective in the management and eradication of breast cancer cells.

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.

Progress in cancer drug delivery based on AS1411 oriented nanomaterials

Targeted cancer therapy has become one of the most important medical methods because of the spreading and metastatic nature of cancer. Based on the introduction of AS1411 and its four-chain structure, this paper reviews the research progress in cancer detection and drug delivery systems by modifying AS1411 aptamers based on graphene, mesoporous silica, silver and gold. The application of AS1411 in cancer treatment and drug delivery and the use of AS1411 as a targeting agent for the detection of cancer markers such as nucleoli were summarized from three aspects of active targeting, passive targeting and targeted nucleic acid apharmers. Although AS1411 has been withdrawn from clinical trials, the research surrounding its structural optimization is still very popular. Further progress has been made in the modification of nanoparticles loaded with TCM extracts by AS1411.

Graphene Based Nanohybrid Aptasensors in Environmental Monitoring: Concepts, Design and Future Outlook

In view of ever-increasing environmental pollution, there is an immediate requirement to promote cheap, multiplexed, sensitive and fast biosensing systems to monitor these pollutants or contaminants. Aptamers have shown numerous advantages in being used as molecular recognition elements in various biosensing devices. Graphene and graphene-based materials/nanohybrids combined with several detection methods exhibit great potential owing to their exceptional optical, electronic and physicochemical properties which can be employed extensively to monitor environmental contaminants. For environmental monitoring applications, aptamers have been successfully combined with graphene-based nanohybrids to produce a wide range of innovative methodologies. Aptamers are immobilized at the surface of graphene based nanohybrids via covalent and non-covalent strategies. This review highlights the design, working principle, recent developmental advances and applications of graphene based nanohybrid aptasensors (GNH-Apts) (since January 2014 to September 2021) with a special emphasis on two major signal-transduction methods, i.e., optical and electrochemical for the monitoring of pesticides, heavy metals, bacteria, antibiotics, and organic compounds from different environmental samples (e.g., water, soil and related). Lastly, the challenges confronted by scientists and the possible future outlook have also been addressed. It is expected that high-performance graphene-based nanohybrid aptasensors would find broad applications in the field of environmental monitoring.

Nanotheranostics: A powerful next-generation solution to tackle hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an epidemic burden and remains highly prevalent worldwide. The significant mortality rates of HCC are largely due to the tendency of late diagnosis and the multifaceted, complex nature of treatment. Meanwhile, current therapeutic modalities such as liver resection and transplantation are only effective for resolving early-stage HCC. Hence, alternative approaches are required to improve detection and enhance the efficacy of current treatment options. Nanotheranostic platforms, which utilize biocompatible nanoparticles to perform both diagnostics and targeted delivery, has been considered a potential approach for cancer management in the past few decades. Advancement of nanomaterials and biomedical engineering techniques has led to rapid expansion of the nanotheranostics field, allowing for more sensitive and specific diagnosis, real-time monitoring of drug delivery, and enhanced treatment efficacies across various malignancies. The focus of this review is on the applications of nanotheranostics for HCC. The review first explores the current epidemiology and the commonly encountered obstacles in HCC diagnosis and treatment. It then presents the current technological and functional advancements in nanotheranostic technology for cancer in general, and then specifically explores the use of nanotheranostic modalities as a promising option to address the key challenges present in HCC management.

Aptamer grafted nanoparticle as targeted therapeutic tool for the treatment of breast cancer

Breast carcinomas repeat their number and grow exponentially making it extremely frequent malignancy among women. Approximately, 70-80% of early diagnosed or non-metastatic conditions are treatable while the metastatic cases are considered ineffective to treat with current ample amount of therapy. Target based anti-cancer treatment has been in the limelight for decades and is perceived significant consideration of scientists. Aptamers are the 'coming of age' therapeutic approach, selected using an appropriate tool from the library of sequences. Aptamers are non-immunogenic, stable, and high-affinity ligand which are poised to reach the clinical benchmark. With the heed in nanoparticle application, the delivery of aptamer to the specific site could be enhanced which also protects them from nuclease degradation. Moreover, nanoparticles due to robust structure, high drug entrapment, and modifiable release of cargo could serve as a successful candidate in the treatment of breast carcinoma. This review would showcase the method and modified method of selection of aptamers, aptamers that were able to make its way towards clinical trial and their targetability and selectivity towards breast cancers. The appropriate usage of aptamer-based biosensor in breast cancer diagnosis have also been discussed.

Biomacromolecule-Functionalized Nanoparticle-Based Conjugates for Potentiation of Anticancer Therapy

Cancer is a rapidly growing life-threatening disease that affected 18.1 million people worldwide in 2018. Various conventional techniques like surgery, radiation, and chemotherapy are considered as a mainstream treatment for patients but show some limitations like cytotoxicity due to off-targeted action, poor intra-tumor localization, development of multi-drug resistance by tumor cells, physical and psychological stresses, etc. Such limitations have motivated the scientists to work towards more patient-centric and precision therapy using advanced drug delivery systems like liposomes, nanoparticles, nanoconjugates, etc. However, these carriers also face limitations like poor biocompatibility, lesser payload capacity, leakage of encapsulated drug, and short-term stability. So, this review article explores the profound insights for the development of biomacromolecule-functionalized nanoconjugates to potentiate the anticancer activity of therapeutic agents for various cancers like lung, colorectal, ovarian, breast and liver cancer. Researchers have shown interest in biofunctionalized nanoconjugates because of advantages like biocompatibility, site-specificity with better localization, higher entrapment with long-term stability and lesser off-target toxicity. The progressive trend of biomacromolecule nanoconjugates will encourage further research for the development of effective transport of drugs, nutraceuticals and phytoconstituents for on-site effect at cancer microenvironment and tumor cells with higher safety profile.

Titanium and Iron Oxide Nanoparticles for Cancer Therapy: Surface Chemistry and Biological Implications

Currently, cancer is among the most challenging diseases due to its ability to continuously evolve into a more complex muldimentional system, in addition to its high capability to spread to other organs and tissues. In this context, the relevance of nanobiomaterials (NBMs) for the development of new more effective and less harmful treatments is increasing. NBMs provide the possibility of combining several functionalities on a single system, expectedly in a synergic way, to better perform the treatment and cure. However, the control of properties such as colloidal stability, circulation time, pharmacokinetics, and biodistribution, assuring the concentration in specific target tissues and organs, while keeping all desired properties, tends to be dependent on subtle changes in surface chemistry. Hence, the behavior of such materials in different media/environments is of uttermost relevance and concern since it can compromise their efficiency and safety on application. Given the bright perspectives, many efforts have been focused on the development of nanomaterials fulfilling the requirements for real application. These include robust and reproducible preparation methods to avoid aggregation while preserving the interaction properties. The possible impact of nanomaterials in different forms of diagnosis and therapy has been demonstrated in the past few years, given the perspectives on how revolutionary they can be in medicine and health. Considering the high biocompatibility and suitability, this review is focused on titanium dioxide– and iron oxide–based nanoagents highlighting the current trends and main advancements in the research for cancer therapies. The effects of phenomena, such as aggregation and agglomeration, the formation of the corona layer, and how they can compromise relevant properties of nanomaterials and their potential applicability, are also addressed. In short, this review summarizes the current understanding and perspectives on such smart nanobiomaterials for diagnostics, treatment, and theranostics of diseases.

Dual targeting smart drug delivery system for multimodal synergistic combination cancer therapy with reduced cardiotoxicity

This study first reports the development of a smart drug delivery system (DDS) for multimodal synergistic cancer therapy combining chemo-photothermal-starvation approaches. A magnetic photothermal agent was synthesized by preparing iron oxide (IO) nanoparticles (NPs) with covalently attached indocyanine green (ICG) and glucose oxidase (GOx) (ICGOx@IO). Synthesized ICGOx@IO NPs were co-encapsulated with doxorubicin (Dox) and EGCG ((-)-epigallocatechin-3-gallate) inside PLGA (poly(lactic-co-glycolic acid)) NPs using multiple emulsion solvent evaporation method. Such formulation gave the advantage of triggered drug release by near-infrared (NIR) laser irradiation (808 nm at 1 W/cm²). RGD peptide was attached to the surface of PLGA NPs and the final hydrodynamic size was around 210 nm. Dual targeting by peptide and 240 mT external magnet significantly improved cellular uptake. Cellular uptake was observed using FACS, electron and optical microscopy. Dual targeting along with laser irradiation could reduce in vitro cell viability by 90 ± 2% (Dox-equivalent dose: 10 µg/ml) and complete tumor ablation was achieved in vivo due to synergetic therapeutic effect. Another attractive feature of the DDS was the significant reduction of cardiotoxicity of doxorubicin by EGCG. This new platform is thus expected to hold strong promise for future multimodal combination therapy of cancers. STATEMENT OF SIGNIFICANCE: Doxorubicin is one of the most studied and effective chemotherapeutic agents whose application is hindered due to its cardiotoxicity. In this study, we used (-)-Epigallocatechin-3-gallate (EGCG) to overcome that limitation. However, drug delivery to tumor sites with no/minimum accumulation in healthy organs is always challenging. Although peptide-based targeting is very popular, the effectiveness of receptor/ligand binding active targeting is sometimes questioned which motivated us to apply dual targeting approach. Multimodal therapies can exhibit synergistic effects and subsequently reduce the required dose of drug over monotherapy. We aimed to achieve chemo-photothermal-starvation combination therapy in this study and such achievement is yet to be reported. Our developed system also has the advantage of triggered drug release by near-infrared (NIR) laser irradiation.

Aptamer-mediated synthesis of multifunctional nano-hydroxyapatite for active tumour bioimaging and treatment

OBJECTIVES

The nano-hydroxyapatite (nHAp) is widely used to develop imaging probes and drug carriers due to its excellent bioactivity and biocompatibility. However, traditional methods usually need cumbersome and stringent conditions such as high temperature and post-modification to prepare the functionalized nHAp, which do not benefit the particles to enter cells due to the increased particle size. Herein, a biomimetic synthesis strategy was explored to achieve the AS1411-targeted tumour dual-model bioimaging using DNA aptamer AS1411 as a template. Then, the imaging properties and the biocompatibility of the synthesized AS-nFAp:Gd/Tb were further investigated.

MATERIALS AND METHODS

The AS-nFAp:Gd/Tb was prepared under mild conditions through a one-pot procedure with AS1411 as a template. Besides, the anticancer drug DOX was loaded to AS-nFAp:Gd/Tb so as to achieve the establishment of a multifunctional nano-probe that integrated the tumour diagnosis and treatment. The AS-nFAp:Gd/Tb was characterized by transmission electron microscopy (TEM), energy disperse X-ray Spectroscopy (EDS) mapping, X-ray photoelectron spectroscopy (XPS) spectrum, X-ray diffraction (XRD), fourier-transformed infrared (FTIR) spectroscopy, capillary electrophoresis analyses, zeta potential and particle sizes. The in vitro magnetic resonance imaging (MRI) and fluorescence imaging were performed on an MRI system and a confocal laser scanning microscope, respectively. The potential of the prepared multifunctional nHAp for a targeted tumour therapy was investigated by a CCK-8 kit. And the animal experiments were conducted on the basis of the guidelines approved by the Animal Care and Use Committee of Sichuan University, China.

RESULTS

In the presence of AS1411, the as-prepared AS-nFAp:Gd/Tb presented a needle-like morphology with good monodispersity and improved imaging performance. Furthermore, due to the specific binding between AS1411 and nucleolin up-expressed in cancer cells, the AS-nFAp:Gd/Tb possessed excellent AS1411-targeted fluorescence and MRI imaging properties. Moreover, after loading chemotherapy drug DOX, in vitro and in vivo studies showed that DOX@AS-nFAp:Gd/Tb could effectively deliver DOX to tumour tissues and exert a highly effective tumour inhibition without systemic toxicity compared with pure DOX.

CONCLUSIONS

The results indicated that the prepared multifunctional nHAp synthesized by a novel biomimetic strategy had outstanding capabilities of recognition and treatment for the tumour and had good biocompatibility; hence, it might have a potential clinical application in the future.

Targeted SPION siderophore conjugate loaded with doxorubicin as a theranostic agent for imaging and treatment of colon carcinoma

Recently, the siderophores have opened new horizons in nanomedicine. The current study aimed to design a theranostic platform based on superparamagnetic iron oxide nanoparticles-pyoverdine (SPION/PVD) conjugates bound to MUC1 aptamer (MUC1_Apt) and loaded with doxorubicin (DOX) as an anti-cancer agent. The SPION/PVD complex was covalently conjugated to MUC1_Apt and loaded with DOX to prepare a targeted drug delivery system (SPION/PVD/MUC1_Apt/DOX). The investigation of cellular cytotoxicity and uptake of formulations by MTT and flow cytometry in both MUC1 positive (C26) and MUC1 negative (CHO) cell lines revealed that MUC1_Apt could improve both cellular uptake and toxicity in the C26 cell line. The evaluation of tumor-targeting activity by in vivo bio-distribution showed that the targeted formulation could enhance tumor inhibitory growth effect and survival rate in C26 tumor-bearing mice. Furthermore, the potential of synthesized SPION/PVD/MUC1_Apt/DOX complex as diagnostic agents was investigated by magnetic resonance imaging (MRI) which improved the contrast of tumor site in MRI. Our findings confirm that aptamer-targeted PVD chelated the SPION as a diagnostic agent and loaded with DOX as a chemotherapeutic drug, would be beneficial as a novel theranostic platform.

pH-controlled nucleolin targeted release of dual drug from chitosan-gold based aptamer functionalized nano drug delivery system for improved glioblastoma treatment

This study developed the pH, and over-expressed nucleolin receptor responsive nano-drug delivery system (nDDS) composed by bio-synthesized gold nanoparticles (Au NPs), chitosan (CS) with aptamer (Apt) to deliver the 5-fluorouracil (5FU) and doxorubicin (Dox) for the improved glioblastoma treatment. The characterization results demonstrated that Apt-Dox-CS-Au-5FU NPs were monodispersed in nature with an average hydrodynamic particle size of 196.2 ± 2.89 nm and zeta potential of 16.26 ± 0.51 mV. The drug release, drug encapsulation efficiency (DEE), and loading efficiency (DLE) were measured by HPLC. The pH-responsive dual drug release was instigated the higher glioblastoma cell death instead of the single drug release through G0/G1 phase cell cycle arrest. In addition, the internalization of Apt-Dox-CS-Au-5FU NPs in cell organelles was affirmed by bio-TEM analysis. Overall, this work revealed the newly designed drug-loaded smart nDDS improved the glioblastoma treatments.

Doxorubicin Loaded Dextran-coated Superparamagnetic Iron Oxide Nanoparticles with Sustained Release Property: Intracellular Uptake, Pharmacokinetics, and Biodistribution Study

BACKGROUND

Due to the short biological half-life and serious side effects (especially for heart and kidney), the application of Doxorubicin (Dox) in clinical therapy is strictly limited. To overcome these shortcomings, a novel sustained release formulation of doxorubicin-loaded dextran-coated superparamagnetic iron oxide nanoparticles (Dox-DSPIONs) was prepared.

OBJECTIVE

The purpose of this study was to evaluate the intracellular uptake behavior of Dox-DSPIONs and to investigate their pharmacokinetics and biodistribution properties.

METHOD

Confocal laser scanning microscopy was employed to study the intracellular uptake and release properties of Dox from Dox-DSPIONs in SMMC-7721 cells. Simple high-performance liquid chromatography with fluorescence detection (HPLC-FLD) method was established to study the pharmacokinetics and biodistribution properties of Dox-DSPIONs in vivo after intravenous administration and compared with free Dox.

RESULTS

Intracellular uptake experiment indicated that Dox could be released sustainedly from Dox-DSPIONs over time. The pharmacokinetics parameters displayed that the T1/2and AUC0-24h of Dox-DSPIONs were higher than those of free Dox, while the Cmax of Dox-DSPIONs was significantly lower than that of free drug. The biodistribution behaviors of the drug were altered by Dox-DSPIONs in mice, which showed obvious liver targeting, and significantly reduced the distribution of the drug in the heart and kidney.

CONCLUSION

Dox-DSPIONs have the sustained-release property in vitro and in vivo, which could significantly prolong blood circulation time, improve bioavailability, and reduce the side effects of Dox. Therefore, the novel formulation of the Dox-DSPIONs has the potential as a promising drug delivery system in cancer therapy.

Cell surface nucleolin as active bait for nanomedicine in cancer therapy: a promising option

Conventional chemotherapy used against cancer is mostly limited due to their non-targeted nature, affecting normal tissue and causing undesirable toxic effects to the affected tissue. With the aim of improving these treatments both therapeutically and in terms of their safety, numerous studies are currently being carried out using nanoparticles (NPs) as a vector combining tumor targeting and carrying therapeutic tools. In this context, it appears that nucleolin, a molecule over-expressed on the surface of tumor cells, is an interesting therapeutic target. Several ligands, antagonists of nucleolin of various origins, such as AS1411, the F3 peptide and the multivalent pseudopeptide N6L have been developed and studied as therapeutic tools against cancer. Over the last ten years or so, numerous studies have been published demonstrating that these antagonists can be used as tumor targeting agents with NPs from various origins. Focusing on nucleolin ligands, the aim of this article is to review the literature recently published or under experimentation in our research team to evaluate the efficacy and future development of these tools as anti-tumor agents.

Trends in targeted delivery of nanomaterials in colon cancer diagnosis and treatment

Colon cancer is an adenocarcinoma, which subsequently develops into malignant tumors, if not treated properly. The current colon cancer therapy mainly revolves around chemotherapy, radiotherapy and surgery, but the search continues for more effective interventions. With the advancement of nanoparticles (NPs), it is now possible to diagnose and treat colon cancers with different types, shapes, and sizes of NPs. Nanoformulations such as quantum dots, iron oxide, polymeric NPs, dendrimers, polypeptides, gold NPs, silver NPs, platinum NPs, and cerium oxide have been either extensively used alone or in combination with other nanomaterials or drugs in colon cancer diagnosis, and treatments. These nanoformulations possess high biocompatibility and bioavailability, which makes them the most suitable candidates for cancer treatment. The size and shape of NPs are critical to achieving an effective drug delivery in cancer treatment and diagnosis. Most NPs currently are under different testing phases (in vitro, preclinical, and clinical), whereas some of them have been approved for therapeutic applications. We have comprehensively reviewed the recent advances in the applications of NPs-based formulations in colon cancer diagnosis and treatment.

Aptamer-Driven Toxin Gene Delivery in U87 Model Glioblastoma Cells

A novel suicide gene therapy approach was tested in U87 MG glioblastoma multiforme cells. A 26nt G-rich double-stranded DNA aptamer (AS1411) was integrated into a vector at the 5' of a mammalian codon-optimized saporin gene, under CMV promoter. With this plasmid termed "APTSAP", the gene encoding ribosome-inactivating protein saporin is driven intracellularly by the glioma-specific aptamer that binds to cell surface-exposed nucleolin and efficiently kills target cells, more effectively as a polyethyleneimine (PEI)-polyplex. Cells that do not expose nucleolin at the cell surface such as 3T3 cells, used as a control, remain unaffected. Suicide gene-induced cell killing was not observed when the inactive saporin mutant SAPKQ DNA was used in the (PEI)-polyplex, indicating that saporin catalytic activity mediates the cytotoxic effect. Rather than apoptosis, cell death has features resembling autophagic or methuosis-like mechanisms. These main findings support the proof-of-concept of using PEI-polyplexed APTSAP for local delivery in rat glioblastoma models.

Immune Cell Membrane-Coated Biomimetic Nanoparticles for Targeted Cancer Therapy

Nanotechnology has provided great opportunities for managing neoplastic conditions at various levels, from preventive and diagnostic to therapeutic fields. However, when it comes to clinical application, nanoparticles (NPs) have some limitations in terms of biological stability, poor targeting, and rapid clearance from the body. Therefore, biomimetic approaches, utilizing immune cell membranes, are proposed to solve these issues. For example, macrophage or neutrophil cell membrane coated NPs are developed with the ability to interact with tumor tissue to suppress cancer progression and metastasis. The functionality of these particles largely depends on the surface proteins of the immune cells and their preserved function during membrane extraction and coating process on the NPs. Proteins on the outer surface of immune cells can render a wide range of activities to the NPs, including prolonged blood circulation, remarkable competency in recognizing antigens for enhanced targeting, better cellular interactions, gradual drug release, and reduced toxicity in vivo. In this review, nano-based systems coated with immune cells-derived membranous layers, their detailed production process, and the applicability of these biomimetic systems in cancer treatment are discussed. In addition, future perspectives and challenges for their clinical translation are also presented.

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.

Thrombolytic Agents: Nanocarriers in Controlled Release

Thrombosis is a life-threatening pathological condition in which blood clots form in blood vessels, obstructing or interfering with blood flow. Thrombolytic agents (TAs) are enzymes that can catalyze the conversion of plasminogen to plasmin to dissolve blood clots. The plasmin formed by TAs breaks down fibrin clots into soluble fibrin that finally dissolves thrombi. Several TAs have been developed to treat various thromboembolic diseases, such as pulmonary embolisms, acute myocardial infarction, deep vein thrombosis, and extensive coronary emboli. However, systemic TA administration can trigger non-specific activation that can increase the incidence of bleeding. Moreover, protein-based TAs are rapidly inactivated upon injection resulting in the need for large doses. To overcome these limitations, various types of nanocarriers have been introduced that enhance the pharmacokinetic effects by protecting the TA from the biological environment and targeting the release into coagulation. The nanocarriers show increasing half-life, reducing side effects, and improving overall TA efficacy. In this work, the recent advances in various types of TAs and nanocarriers are thoroughly reviewed. Various types of nanocarriers, including lipid-based, polymer-based, and metal-based nanoparticles are described, for the targeted delivery of TAs. This work also provides insights into issues related to the future of TA development and successful clinical translation.

Aptamer-conjugated PLGA nanoparticles for delivery and imaging of cancer therapeutic drugs

Most problems associated with chemotherapeutic agents involve non-specific cytotoxicity, low intratumoral accumulation and drug resistance. Targeted drug delivery systems (TDDS) based on nanoparticles (NPs) are a new strategy for better therapeutic efficiency, along with reduction of side effects commonly seen with cancer drugs. Poly (lactic-co-glycolic acid) (PLGA), as one of the furthest developed synthetic polymer, has gained significant attention because of excellent properties-including biodegradability and biocompatibility, controlled release of drug, protection of drug or gene from decomposition and ability to modify surface with targeting agents for both cancer diagnosis and therapy. Aptamers are single-stranded RNA or DNA that can fold through intramolecular interactions into specific three-dimensional structures to selectively and exclusively bind with interested biomarkers. In this review, we explain the latest developments regarding the application of aptamer-decorated PLGA NPs in delivery of therapeutic agents or cancer-related genes into cancer cells. Additionally, we discuss the most recent efforts in the field of aptamer-grafted PLGA-based NPs as theranostics and stimuli-responsive agents.

Biological studies of an ICG-tagged aptamer as drug delivery system for malignant melanoma

Malignant melanoma accounts for about 1% of all skin malignant tumors and represents the most aggressive and lethal form of skin cancer. Clinically, there exist different therapeutic options for melanoma treatment, such as surgery, chemotherapy, radiotherapy, photodynamic therapy and immunotherapy. However, serious adverse effects usually arise, and survival rates are still low because a high number of patients present relapses within 6-9 months after therapy. AS1411 is a G-quadruplex (G4) aptamer capable of tumor-specific recognition, since it binds to nucleolin, a multi-functional protein expressed in many different types of cancer cells. In this work, we present a novel drug delivery system composed of AS1411 and indocyanine green (ICG) to track its accumulation in tumoral cells in a melanoma mouse model. Using a simple supramolecular strategy, we conjugated the complex AS1411-ICG with C₈ ligand, an acridine orange derivative with potential anticancer ligand. Then, we performed in vitro cytotoxicity experiments using the B16 mouse melanoma cell line, and in vivo experiments using a B16 mouse melanoma model to study biodistribution and histological changes. The circular dichroism (CD) data suggest that C₈ does not affect the parallel G4 topology of AS1411-ICG, whereas it increases its thermal stability. Incubation of B16 melanoma cells with the AS1411-ICG complex associated with C₈ increases the cytotoxicity compared with AS1411-ICG alone. From the in vivo studies, we conclude that both AS1411-ICG and AS1411-ICG-C₈ presented the potential to accumulate preferentially in tumor tissues. Moreover, these compounds seem to be efficiently removed from the mice's bodies through kidney clearance. In summary, these results suggest that these complexes derived from AS1411 aptamer could act as a delivery system of ligands with antitumoral activity for in vivo melanoma therapy.

Combination therapy using Smac peptide and doxorubicin-encapsulated MUC 1-targeted polymeric nanoparticles to sensitize cancer cells to chemotherapy: An in vitro and in vivo study

Targeting inhibitors of apoptosis proteins (IAPs) family comprising high level expression in many cancer cells, could sensitize tumor cells to conventional chemotherapies. In the present study, we designed both doxorubicin and SmacN6 (an antagonist of the IAPs) encapsulated polymeric nanoparticles (NPs) and investigated their synergistic effect of combination therapy in vitro and in vivo. According to the results, NPs-SmacN6 significantly enhanced the cytotoxicity effect of NPs-DOX and reduced its IC₅₀ in MCF-7, 4T1 and C26 cancer cells. Western blot analysis confirmed mechanism of cell apoptosis via caspase activation through intrinsic and also extrinsic pathways. Moreover, 5TR1 aptamer-modified NPs could effectively deliver DOXor SmacN6 to C26 cancer cells (MUC1 positive) in comparison with the non-targeted one (p < 0.001). However, they could not be efficiently internalized into CHO cells (MUC1 negative), showing less cytotoxicity in this cell line. In vivo experiments in BALB/c mice bearing C26 tumor indicated that Apt-NPs-DOX in combination with Apt-NPs-SmacN6 had significant tumor growth inhibition in comparison with mice receiving either free DOX or Apt-NPs-DOX with p < 0.0001 and p < 0.05, respectively. Our results revealed that combination therapy of DOX and SmacN6 via Apt-modified nanoparticles can lead to improvement of therapeutic index of DOX in MUC1 positive cancer cells.

Laser-triggered collaborative chemophotothermal effect of gold nanoparticles for targeted colon cancer therapy

Nanotechnology has shown advantages for cancer treatment. Multimodal nanoparticles (NPs) combining chemotherapy and photothermal therapy are promising and elicit synergetic benefit. However, there were still less multifunctional nanomaterials with good targeting and anti-tumor property applied as the colon cancer therapeutic strategy. In this study, we designed the gold NPs modified with AS1411 and DNA riched of GC intercalation (hairpin DNA) with doxorubicin (DOX) for targeted chemotherapy and NIR laser-triggered chemo-photothermal effect (PTT). We took advantage of PTT effect to realize DOX release from hairpin DNA. We also demonstrated AS1411 based NPs exhibited remarkable targeted binding towards SW480 colon cancer cells in vitro and enhanced uptake inside the cells. Strikingly, AS1411 based NPs exhibited the most efficient cytotoxicity and markedly enhanced inhibition effect on cells proliferation to SW480 cells under laser exposure when compared to the NPs merely with PTT or chemotherapy. Our study appears to provide an alternative nanoplatform with good targeted and chemo-photothermal therapy against colon cancer.

Magnetic Colloidal Particles in Combinatorial Thin-Film Gradients for Magnetic Resonance Imaging and Hyperthermia

A stable oil-in-water (O/W) magnetic emulsion was prepared by the emulsification of organic ferrofluid in an aqueous media, and its theranostic applications were investigated. The synthesis and characterization of the organic ferrofluid were carried out comprising of superparamagnetic maghemite nanoparticles with oleic acid coating stabilized in octane. Both exhibit spherical morphology with a mean size of 6 nm and 200 nm, respectively, as determined by TEM. Thermogravimetric analysis was carried out to determine the chemical composition of the emulsion. The research work described here is novel and elaborates the fabrication of thin-film gradients with 5, 10, 15, and 20 bilayers by layer-by-layer technique using polydimethyl diallyl ammonium chloride (PDAC) and prepared magnetic colloidal particles. The thin-film gradients were characterized for their roughness, morphology, and wettability. The developed gradient films and colloids were explored in magnetic resonance imaging (MRI) and hyperthermia. T1- and T2-weighted images and their corresponding signal intensities were obtained at 1.5 T. A decreasing trend in signal intensities with an increase in nanoparticle concentration in colloids and along the gradient was observed in T2-weighted images. The hyperthermia capability was also evaluated by measuring temperature rise and calculating specific absorption rates (SAR). The SAR of the colloids at 259 kHz, 327 kHz, and 518 kHz were found to be 156 W/g, 255 W/g, and 336 W/g, respectively. The developed magnetic combinatorial thin-film gradients present a significant potential for the future efficient simultaneous diagnostic and therapeutic bioapplications.

In vitro Biological Tests as the First Tools To Validate Magnetic Nanotheranostics for Colorectal Cancer Models

Colorectal cancer (CRC) remains a leading cause of cancer death. Nanotechnology has focused on reaching more effective treatments. In this concern, magnetic nanoparticles (MNPs) have been studied for a wide range of biomedical applications related to CRC, such as diagnostic imaging, drug delivery and thermal therapy. However, limited research is currently found in the open literature that refers to nanosystems combining all these mentioned areas (theranostics). When developing nanosystems intended as theranostics applied to CRC, possible variations between patients must be considered. Therefore, multiple in vitro assays are required as guidance for future preclinical and clinical trials. The objective of this contribution is to evaluate the available and recent literature regarding the interactions of MNP and CRC models, aiming to critically analyze the information given by the commonly used assays and evaluate the data provided by each one with a view to implementing this novel technology in CRC diagnostics and therapy.

Polymer Coated Iron Nanoparticles: Radiolabeling & In vitro Studies

BACKGROUND

Superparamagnetic iron oxide nanoparticles (SPIONs) have been extensively used for targeted drug delivery systems due to their unique magnetic properties.

OBJECTIVE

In this study, it has been aimed to develop a novel targeted ^99mTc radiolabeled polymeric drug delivery system for Gemcitabine (GEM).

METHODS

Gemcitabine, an anticancer agent, was encapsulated into polymer nanoparticles (PLGA) together with iron oxide nanoparticles via double emulsion technique and then labeled with ^99mTc. SPIONs were synthesized by reduction-coprecipitation method and encapsulated with oleic acid for surface modification. Size distribution and the morphology of the synthesized nanoparticles were characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM), respectively. The radiolabeling yield of SPION-PLGAGEM nanoparticles was determined via Thin Layer Radio Chromatography (TLRC). Cytotoxicity of GEM loaded SPION-PLGA was investigated on MDA-MB-231 and MCF7 breast cancer cells in vitro.

RESULTS

SEM images displayed that the average size of the drug-free nanoparticles was 40 nm and the size of the drug-loaded nanoparticles was 50 nm. The diameter of nanoparticles was determined as 366.6 nm by DLS, while zeta potential was found as 29 mV. SPION was successfully coated with PLGA, which was confirmed by FTIR. GEM encapsulation efficiency of SPION-PLGA was calculated as 4±0.16% by means of HPLC. Radiolabeling yield of SPION-PLGA-GEM nanoparticles was determined as 97.8±1.75% via TLRC. Cytotoxicity of GEM loaded SPION-PLGA was investigated on MDA-MB-231 and MCF7 breast cancer cells. SPION-PLGA-GEM showed high uptake on MCF-7, while the incorporation rate was increased for both cell lines with external magnetic field application.

CONCLUSION

^99mTc labeled SPION-PLGA nanoparticles loaded with GEM may overcome some of the obstacles in anti-cancer drug delivery because of their appropriate size, non-toxic, and superparamagnetic characteristics.

Design and synthesis of aptamer AS1411-conjugated EG@TiO2@Fe2O3nanoparticles as a drug delivery platform for tumor-targeted therapy

AS1411@GMBS@EG@TiO₂@Fe₂O₃nanoparticle is an effective and safe pH-responsive sustained release system for targeted drug delivery into nucleolin-positive cells.

A nano-based thermotherapy for cancer stem cell-targeted therapy

Cancer stem cells (CSCs) exhibit high resistance to conventional therapy and are responsible for cancer metastasis and tumor relapse.