Aptamer-based nanoparticles for cancer targeting

Abstract

Background: The use of mesoporous silica for cancer targeting is increasing rapidly. The association between rigid model of nanoparticles such as mesoporous silica and biological compounds with affinity for oncological diseases is a very promising drug targeting system nowadays.

Methods: In this study, we used the mesoporous silica (SBA-15) associated with aptamer (functionalized for the tumor marker MUC-1).

Results: The results obtained in the characterization were quite interesting and demonstrated that the silica produced were very uniform and with a size range of 50–100?nm. Thus, the results of cytotoxicity demonstrated that there is no cytotoxicity related to the nanoparticle.

Conclusion: We conclude that although further studies are required, the nanoparticle mesoporous silica model loaded with aptamer is very functional and its use can be widespread for other application especially in nuclear medicine.     

Methotrexate-conjugated quantum dots: synthesis,characterisation and cytotoxicity in drug resistant cancer cells

Methotrexate (MTX), a folic acid derivative, is a potent anticancer used for treatment of different malignancies, but possible initiation of drug resistance to MTX by cancer cells has limited its applications. Nanoconjugates (NCs) of MTX to quantum dots (QDs) may favour the cellular uptake via folate receptors (FRs)-mediated endocytosis that circumvents the efflux functions of cancer cells. We synthesised MTX-conjugated l-cysteine capped CdSe QDs (MTX-QD nanoconjugates) and evaluated their internalisation and cytotoxicity in the KB cells with/without resistancy to MTX. The NCs were fully characterised by high resolution transmission electron microscopy (HR-TEM), atomic force microscopy (AFM), dynamic light scattering (DLS) and optical spectroscopy. Upon conjugation with MTX, the photoluminescence (PL) properties of QDs altered, while an obvious quenching in PL of QDs was observed after physical mixing. The MTX-QD nanoconjugates efficiently internalised into the cancer cells, and induced markedly high cytotoxicity (IC₅₀, 12.0?µg/mL) in the MTX-resistant KB cells as compared to the free MTX molecules (IC₅₀,105.0?µg/mL), whereas, these values were respectively about 7.0 and 0.6?µg/mL in the MTX-sensitive KB cells. Based on these findings, the MTX-QD nanoconjugates are proposed for the targeted therapy of MTX-resistant cancers, which may provide an improved outcome in the relapsed FR-overexpressing cancers.     

多柔比星纳米递药系统在三阴性乳腺癌靶向治疗中的应用

三阴性乳腺癌为高度恶性肿瘤。多柔比星是三阴性乳腺癌的常规化疗药物,该药药理作用是通过嵌入DNA碱基对之间,干扰基因转录,抑制mRNA和DNA合成。常规给药方式对正常组织损伤严重。多柔比星纳米递药系统借助肿瘤酸性微环境实现缓控释效应,多柔比星与肿瘤细胞的组织相容性增加,对正常组织影响较小。该系统有效抑制和杀灭肿瘤细胞,明显减轻正常细胞的细胞毒性。本文综述了近年来多柔比星靶向纳米递药系统的应用,以期开拓三阴性乳腺癌的的靶向治疗新视野。     

Nanoparticulate carriers: an emerging tool for breast cancer therapy

Breast cancer is a leading cause of death for woman in the world. Cancer has the potential to spread to different organs around the body, and form metastases that can even develop after surgical removal of the primary tumour. Nanotechnology offers new promising strategies for the treatment of breast cancer, and has emerged as a powerful tool for fighting cancer. Nanoparticles can be fabricated to perform more than one task simultaneously, and can have a number of roles, such as acting as a therapeutic agent, drug delivery vehicle and/or tumour imaging agent. This review will focus on various forms of nanoparticles serving as potential agents for cancer therapeutics, illustrating their use in breast cancer therapies. This article also highlights the properties, current progress in the design and engineering of nanoparticles.     

Nanotechnology in cancer therapy

Abstract

Cancer is one of the major causes of mortality worldwide and advanced techniques for therapy are urgently needed. The development of novel nanomaterials and nanocarriers has allowed a major drive to improve drug delivery in cancer. The major aim of most nanocarrier applications has been to protect the drug from rapid degradation after systemic delivery and allowing it to reach tumor site at therapeutic concentrations, meanwhile avoiding drug delivery to normal sites as much as possible to reduce adverse effects. These nanocarriers are formulated to deliver drugs either by passive targeting, taking advantage of leaky tumor vasculature or by active targeting using ligands that increase tumoral uptake potentially resulting in enhanced antitumor efficacy, thus achieving a net improvement in therapeutic index. The rational design of nanoparticles plays a critical role since structural and physical characteristics, such as size, charge, shape, and surface characteristics determine the biodistribution, pharmacokinetics, internalization and safety of the drugs. In this review, we focus on several novel and improved strategies in nanocarrier design for cancer therapy.     

Multifunctional nanoparticles for targeting cancer and inflammatory diseases

Abstract

The interplay between cancer and inflammation has been well documented over the years and the role of nanomedical technologies for treating both these diseases has become evident over the past few decades. With the advances in nanoparticle-based imaging and therapeutic platforms that can exploit the pathological conditions of the tumor and the inflamed sites to effectively deliver drugs, genes and imaging/contrast agents; the management of such conditions with favorable therapeutic outcomes seems plausible. This review will summarize some of the latest advances in the field of targeted nanomedicine development to combat cancer and inflammation. Illustrative examples of multifunctional-targeted nanosystems are presented that highlight their potential in delivering diverse payloads, including small molecule drugs, nucleic acids and imaging agents for simultaneous theranostic interventions.     

Polymeric micelles with stimuli-triggering systems for advanced cancer drug targeting

Abstract

Since the 1990s, nanoscale drug carriers have played a pivotal role in cancer chemotherapy, acting through passive drug delivery mechanisms and subsequent pharmaceutical action at tumor tissues with reduction of adverse effects. Polymeric micelles, as supramolecular assemblies of amphiphilic polymers, have been considerably developed as promising drug carrier candidates, and a number of clinical studies of anticancer drug-loaded polymeric micelle carriers for cancer chemotherapy applications are now in progress. However, these systems still face several issues; at present, the simultaneous control of target-selective delivery and release of incorporated drugs remains difficult. To resolve these points, the introduction of stimuli-responsive mechanisms to drug carrier systems is believed to be a promising approach to provide better solutions for future tumor drug targeting strategies. As possible trigger signals, biological acidic pH, light, heating/cooling and ultrasound actively play significant roles in signal-triggering drug release and carrier interaction with target cells. This review article summarizes several molecular designs for stimuli-responsive polymeric micelles in response to variation of pH, light and temperature and discusses their potentials as next-generation tumor drug targeting systems.     

Enhancement of cellular uptake and cytotoxicity of curcumin-loaded PLGA nanoparticles by conjugation with anti-P-glycoprotein in drug resistance cancer cells

Aim:

To compare the anti-cancer activity and cellular uptake of curcumin (Cur) delivered by targeted and non-targeted drug delivery systems in multidrug-resistant cervical cancer cells.

Methods:

Cur was entrapped into poly (DL-lactide-co-glycolide) (PLGA) nanoparticles (Cur-NPs) in the presence of modified-pluronic F127 stabilizer using nano-precipitation technique. On the surface of Cur-NPs, the carboxy-terminal of modified pluronic F127 was conjugated to the amino-terminal of anti-P-glycoprotein (P-gp) (Cur-NPs-APgp). The physical properties of the Cur-NPs, including particle size, zeta potential, particle morphology and Cur release kinetics, were investigated. Cellular uptake and specificity of the Cur-NPs and Cur-NPs-APgp were detected in cervical cancer cell lines KB-V1 (higher expression of P-gp) and KB-3-1 (lower expression of P-gp) using fluorescence microscope and flow cytometry, respectively. Cytotoxicity of the Cur-NPs and Cur-NPs-APgp was determined using MTT assay.

Results:

The particle size of Cur-NPs and Cur-NPs-APgp was 127 and 132 nm, respectively. The entrapment efficiency and actual loading of Cur-NPs-APgp (60% and 5 μg Cur/mg NP) were lower than those of Cur-NPs (99% and 7 μg Cur/mg NP). The specific binding of Cur-NPs-APgp to KB-V1 cells was significantly higher than that to KB-3-1 cells. Cellular uptake of Cur-NPs-APgp into KB-V1 cells was higher, as compared to KB-3-1 cells. However, the cellular uptake of Cur-NPs and Cur-NPs-IgG did not differ between the two types of cells. Besides, the cytotoxicity of Cur-NPs-APgp in KB-V1 cells was higher than those of Cur and Cur-NPs.

Conclusion:

The results demonstrate that Cur-NPs-APgp targeted to P-gp on the cell surface membrane of KB-V1 cells, thus enhancing the cellular uptake and cytotoxicity of Cur.     

Introduction of magnetic and supermagnetic nanoparticles in new approach of targeting drug delivery and cancer therapy application

Abstract

In this article, the recent applications of different types of magnetic nanoparticles such as α-Fe₂O₃ (hematite), γ-Fe₂O₃ (maghemite), Fe₃O₄ (magnetite), hexagonal (MFe₁₂O₁₉), garnet (M₃Fe₅O₁₂) and spinel (MFe₂O₄), where M represents one or more bivalent transition metals (Mn, Fe, Co, Ni, Ba, Sr, Cu, and Zn), and different materials for coating the surface of magnetic nanoparticles like poly lactic acid (PLA), doxorubicin hydrophobic (DOX-HCL), paclitaxel (PTX), EPPT-FITC, oleic acid, tannin, 3-Aminopropyltriethoxysilane (APTES), multi-wall carbon nanotubes (CNTs), polyethylenimine (PEI) and polyarabic acid in drug delivery, biomedicine and treatment of cancer, specially chemotherapy, are reviewed. MNPs possess large surface area to volume ratios because of their nano-size, low surface charge at physiological pH and they aggregate easily in solution due to their essential magnetic nature. These materials are widely used in biology and medicine in many cases. One targeted delivery technique that has gained prominence in recent years is the use of magnetic nanoparticles. In these systems, therapeutic compounds are attached to biocompatible magnetic nanoparticles and magnetic fields generated outside the body are focused on specific targets in vivo. The fields capture the particle complex, resulting in enhanced delivery to the target site. Also, the application of brand new supermagnetic nanoparticles, like Ba,SrFe₁₂O₁₉, is considered and studied in this paper.     

Recent trends in targeted therapy of cancer using graphene oxide-modified multifunctional nanomedicines

Rapid progresses in nanotechnology fields have led us to use a number of advanced nanomaterials (NMs) for engineering smart multifunctional nanoparticles (NPs)/nanosystems (NSs) for targeted diagnosis and therapy of various diseases including different types of malignancies. For the effective therapy of any type of solid tumor, the treatment modality should ideally solely target the aberrant cancerous cells/tissue with no/trivial impacts on the healthy cells. One approach to achieve such unprecedented impacts can be fulfilled through the use of seamless multimodal NPs/NSs with photoacoustic properties that can be achieved using advanced NMs such as graphene oxide (GO). It is considered as one of the most promising materials that have been used in the development of various NPs/NSs. GO-based targeted NSs can be engineered as programmable drug delivery systems (DDSs) to perform on-demand chemotherapy combined with photonic energy for photothermal therapy (PTT) or photodynamic therapy (PDT). In the current review, we provide important insights on the GO-based NSs and discuss their potentials for the photodynamic/photothermal ablation of cancer in combination with anticancer agents.     

Clinical translation of folate receptor-targeted therapeutics

Introduction: Folate receptor?α (FR?α) has been established as a membrane marker for ovarian cancer. In addition, it is frequently overexpressed in other major types of epithelial tumors. FR?α-based tumor-targeted therapy and drug carriers have been an active area of laboratory research for more than 20 years. Recently, there has been a great increase in the effort to finally translate this promising technology into the clinic and bring FR-targeted therapeutics into the market.

Areas covered: Two FR-targeted therapeutic agents have moved into Phase III clinical trials, the monoclonal antibody farletuzumab and the low molecular weight vintafolide, combined with etarfolatide as a companion imaging agent, representing two alternative strategies for targeting the FR.

Expert opinion: Each of the two strategies has advantages and disadvantages. Identification of the best target patient population is likely critical to the ultimate success of FR-targeted agents in the clinic. A successful clinical strategy may require the integration between FR expression analysis and an optimal combination of FR-targeted therapy and standard chemotherapy. Advancement into Phase III trials and the ongoing clinical development of several additional folate conjugates are likely to usher in a new era of clinical translation and validation of FR-targeted imaging and therapeutic agents.     

Novel methods of targeted drug delivery: the potential of multifunctional nanoparticles

Nanomaterials have been demonstrated as useful tools for molecular imaging, molecular diagnosis and targeted therapy in biomedical research. The main advantages of such nanomaterials are improved circulation times, precise targeting, enhancement of dissolution rates and enhanced contrast. A challenge and opportunity for nanotechnological strategies is that multiple functionalities, such as therapeutics, targeting, imaging and stimuli responsiveness can be achieved within one nanoparticle. Multifunctional nanoparticles are now actively under investigation and are imminent as the next generation of nanoparticles for providing custom and tailored treatment. This review considers contemporary approaches and possible future directions in the emerging area of multifunctional nanoparticles with a special focus on targeted drug delivery.     

Liposomal cancer therapy: exploiting tumor characteristics

Importance of the field: More than 10 million people worldwide are diagnosed with cancer each year, and the development of effective cancer treatments is consequently of great significance. Cancer therapy is unfortunately hampered by severe dose-limiting side effects that reduce the efficacy of cancer treatments. In the search for more effective cancer treatments, nanoparticle-based drug delivery systems, such as liposomes, that are capable of delivering their drug payload selectively to cancer cells are among the most promising approaches.

Areas covered in this review: This review provides an overview of current strategies for improving the different stages of liposomal cancer therapy, which involve transporting drug-loaded liposomes through the bloodstream, increasing tumor accumulation, and improving drug release and cancer cell uptake after accumulation at the tumor target site.

What the reader will gain: The review focuses on strategies that exploit characteristic features of solid tumors, such as abnormal vasculature, overexpression of receptors and enzymes, as well as acidic and thiolytic characteristics of the tumor microenvironment.

Take home message: It is concluded that the design of new liposomal drug delivery systems that better exploit tumor characteristic features is likely to result in more efficacious cancer treatments.     

WITHDRAWN: 5-Fluorouracil-loaded iron/ethylcellulose (core/shell) nanoparticles for active targeting of cancer

Even though 5-fluorouracil has been demonstrated to display antitumor activity against a wide variety of cancers, it is needed to be administered at high doses to elicit the required therapeutic activity, simultaneously leading to severe side effects. We hypothesized that the efficient delivery of 5-fluorouracil to tumors using a magnetic colloid could reduce the dose required to bring out sufficient therapeutic response. Thus, we have formulated a 5-fluorouracil-loaded magnetic nanomedicine consisting of a magnetic core (iron) and a biocompatible polymeric shell (ethylcellulose), suitable for parenteral administration. These core/shell nanoparticles were synthesized by an emulsion solvent evaporation process. Two drug loading methods were analyzed: the first one based on 5-fluorouracil surface adsorption onto the preformed nanoparticles, and the second method being drug addition prior to the emulsion solvent evaporation process leading to drug entrapment into the polymeric network. 5-Fluorouracil entrapment into the polymeric matrix yielded a higher drug loading and a slower drug release profile as compared with drug adsorption. Finally, as a proof of concept, Prussian blue staining has demonstrated the considerable accumulation of these magnetically guided composite nanoparticles in the tumors, suggesting the potential of this stimuli-sensitive drug carrier for the efficient treatment of cancer by active targeting.     

Actively targeted nanocarriers for drug delivery to cancer cells

Introduction: Progressive breakthroughs in nanomedicine have been instrumental for the clinical translation of actively targeted drug-delivery approaches. Besides storing large payloads of drugs within the nanoparticle core, the conjugation of targeting moieties confers specific targeting ability to the nanoplatforms. In this respect, clinical results suggest that actively targeted nanocarriers can exhibit an overall improved antitumor efficacy, minimizing off-target toxicity.

Areas covered: This review article summarizes the advances in active targeting of nanocarriers to cancer cells. Specifically, we discuss the various types of nanocarriers, describe the receptors that are frequently overexpressed in solid tumors, and discuss how this approach can be used to improve clinical outcomes. We particularly focus on ongoing clinical trials of actively targeted nanoparticles that are yet to be clinically approved.

Expert opinion: Further investment in active targeting will likely pose clinical benefits. We envisage a future requiring the use of longitudinal measures in the clinical setting to profile the patients that are likely to benefit from actively targeted nanocarriers. At the preclinical stage, a complete picture of intratumoral barriers combined with a quantitative approach of the intratumoral fate of nanomaterials will be instrumental in defining more effective strategies to improve their clinical translation.     

Bisphosphonate-coated BSA nanoparticles lack bone targeting after systemic administration

A polymeric conjugate of polyethyleneimine-graft-poly(ethylene glycol) and 2-(3-mercaptopropylsulfanyl)-ethyl-1,1-bisphosphonic acid (PEI-PEG-thiolBP) was prepared and used for surface coating of bovine serum albumin (BSA) nanoparticles (NPs) designed for bone-specific delivery of bone morphogenetic protein-2 (BMP-2). The NP coating was achieved with a dialysis and an evaporation method, and the obtained NPs were characterized by particle size, ζ-potential, morphology, and cytotoxicity in vitro. The particle size and surface charge of the NPs could be effectively tuned by the PEG and thiolBP substitution ratios of the conjugate, the coating method, and the polymer concentration used for coating. The PEG modification on PEI reduced the toxicity of PEI and the coated NPs, based on in vitro assessment with human C2C12 cells and rat bone marrow stromal cells. On the basis of an alkaline phosphatase (ALP) induction assay, the NP-encapsulated BMP-2 displayed full retention of its bioactivity, except for BMP-2 in PEI-coated NPs. By encapsulating ¹²⁵I-labeled BMP-2, the polymer-coated NPs were assessed for hydroxyapatite (HA) affinity; all NP-encapsulated BMP-2 showed significant affinity to HA as compared with free BMP-2 in vitro, and the PEI-PEG-thiolBP coated NPs improved the in vivo retention of BMP-2 compared with uncoated NPs. However, the biodistribution of NPs after intravenous injection in a rat model indicated no beneficial effects of thiolBP-coated NPs for bone targeting. Our results suggested that the BP-conjugated NPs are useful for localized delivery of BMP-2 in bone repair and regeneration, but they are not effective for bone targeting after intravenous administration.     

适配体C2min介导的可靶向2种前列腺癌基因的递送系统

目的 通过合成可靶向两种前列腺癌的基因载体PAMAM-PEG-C2min,以提高基因的转染效率和肿瘤靶向性。方法 将双功能聚乙二醇的一端与聚酰胺-胺（PAMAM）相连,另一端与适配体（C2min）连接,并利用¹H NMR技术对合成的PAMAM-PEG-C2min基因载体进行结构鉴定。通过两种前列腺癌PC3和LNCaP细胞的体外摄取和基因转染实验（包载siR-M基因）,考察纳米复合物的生物学特性。并利用动物活体成像技术考察合成的纳米复合物的体内分布特征。结果 核磁共振结果表明,本研究成功合成了PAMAM-PEG-C2min。PC3和LNCaP细胞对PAMAM-PEG-C2min的摄取结果体现出浓度依赖性。且与不经C2min修饰的PAMA-PEGM相比,PAMAM-PEG-C2min递药系统的基因转染效率和肿瘤细胞靶向性明显提高。体内靶向性结果表明,PAMAM-PEG-C2min可实现同时靶向2种前列腺癌组织的作用。结论 本研究合成的PAMAM-PEG-C2min递送载体具有良好的肿瘤靶向性,为前列腺癌的综合治疗和靶向治疗提供了新的技术平台。     

Microencapsulation of therapeutic bispecific antibodies producing cells: immunotherapeutic organoids for cancer management

Regardless of the important therapeutic advances developed over the last years for the management of cancer, the fact is that many patients still suffer from a tremendous reduction on their quality of life due to lack of complete selectivity of conventionally administered chemotherapeutic drugs. In the search of more efficacious tumor-targeted therapies, the use of bispecific antibodies (bsAbs) capable of simultaneous binding to tumor-associated antigens and to an activating receptor, such as CD3, has emerged as a promising approach. With the intention to complementing and improving this cancer immunotherapy, human HEK-293 cells have been genetically modified ex vivo to secrete a recombinant anti-CEA (carcinoembryonic antigen)?×?anti-CD3 bsAb. After encapsulation in alginate-poly-l-lysine microcapsules, bsAb-secreting HEK-293 cells were monitorized for several weeks. This system has proved to be feasible for the maintenance of cell growth and recombinant antibody production giving proof-of-concept of its use as immunotherapeutic organoids in cancer treatment.     

转铁蛋白受体介导载紫杉醇纳米粒对结肠癌细胞的靶向性研究

目的 制备转铁蛋白受体特异结合肽T7修饰载紫杉醇纳米粒(T7-NPs-PTX),研究其对结肠癌RKO细胞的靶向抑制作用.方法 采用薄层法利备纳米粒共聚焦显微镜观察结肠癌RKO细胞和血管内皮HUVEC细胞对T7-NPs-PTX的摄取情况.MTT实验研究T7-NPs-PTX对结肠癌RKO细胞的毒性;流式细胞仪检测T7-NPs-PTX对结肠癌RKO细胞的凋亡诱导作用.构建RKO细胞肿瘤球模型,研究T7-NPs-PTX对肿瘤球的生长抑制能力.构建结肠癌裸鼠异位模型,研究T7-NPs-PTX对裸鼠肿瘤生长抑制作用.结果 RKO细胞对经过T7修饰后的T7-NPs-PTX摄取显著增加,但HUVEC细胞对T7-NPs-PTX的摄取无显著变化.T7-NPs-PTX对结肠癌RKO细胞的增殖抑制作用和细胞凋亡诱导作用显著强于NPs-PTX和PTX溶液.结论 经过T7修饰后能够增强纳米粒与结肠癌RKO细胞的亲和力,T7-NPs-PTX是一种潜在、高效的结肠癌靶向给药系统.