Two-in-one: combined targeted chemo and gene therapy for tumor suppression and prevention of metastases

Nanotechnology-Based Strategy for Enhancing Therapeutic Efficacy in Pancreatic Cancer: Receptor-Targeted Drug Delivery by Somatostatin Analog

A novel nanotechnology-based drug delivery system (DDS) targeted at pancreatic cancer cells was developed, characterized, and tested. The system consisted of liposomes as carriers, an anticancer drug (paclitaxel) as a chemotherapeutic agent, and a modified synthetic somatostatin analog, 5-pentacarbonyl-octreotide, a ligand for somatostatin receptor 2 (SSTR2), as a targeting moiety for pancreatic cancer. The cellular internalization, cytotoxicity, and antitumor activity of the DDS were tested in vitro using human pancreatic ductal adenocarcinoma (PDAC) cells with different expressions of the targeted SSTR2 receptors, and in vivo on immunodeficient mice bearing human PDAC xenografts. The targeted drug delivery system containing paclitaxel exhibited significantly enhanced cytotoxicity compared to non-targeted DDS, and this efficacy was directly related to the levels of SSTR2 expression. It was found that octreotide-targeted DDS proved exceptionally effective in suppressing the growth of PDAC tumors. This study underscores the potential of octreotide-targeted liposomal delivery systems to enhance the therapeutic outcomes for PDAC compared with non-targeted liposomal DDS and Paclitaxel-Cremophor® EL, suggesting a promising avenue for future cancer therapy innovations.

Nanotechnology-Based RNA Vaccines: Fundamentals, Advantages and Challenges

Over the past decades, many drugs based on the use of nanotechnology and nucleic acids have been developed. However, until recently, most of them remained at the stage of pre-clinical development and testing and did not find their way to the clinic. In our opinion, the main reason for this situation lies in the enormous complexity of the development and industrial production of such formulations leading to their high cost. The development of nanotechnology-based drugs requires the participation of scientists from many and completely different specialties including Pharmaceutical Sciences, Medicine, Engineering, Drug Delivery, Chemistry, Molecular Biology, Physiology and so on. Nevertheless, emergence of coronavirus and new vaccines based on nanotechnology has shown the high efficiency of this approach. Effective development of vaccines based on the use of nucleic acids and nanomedicine requires an understanding of a wide range of principles including mechanisms of immune responses, nucleic acid functions, nanotechnology and vaccinations. In this regard, the purpose of the current review is to recall the basic principles of the work of the immune system, vaccination, nanotechnology and drug delivery in terms of the development and production of vaccines based on both nanotechnology and the use of nucleic acids.

Galactosylated Polymer/Gold Nanorods Nanocomposites for Sustained and Pulsed Chemo-Photothermal Treatments of Hepatocarcinoma

In this paper, we propose a rational design of a hybrid nanosystem capable of locally delivering a high amount of hydrophobic anticancer drugs (sorafenib or lenvatinib) and heat (hyperthermia) in a remote-controlled manner. We combined in a unique nanosystem the excellent NIR photothermal conversion of gold nanorods (AuNRs) with the ability of a specially designed galactosylated amphiphilic graft copolymer (PHEA-g-BIB-pButMA-g-PEG-GAL) able to recognize hepatic cells overexpressing the asialoglycoprotein receptor (ASGPR) on their membranes, thus giving rise to a smart composite nanosystem for the NIR-triggered chemo-phototherapy of hepatocarcinoma. In order to allow the internalization of AuNRs in the hydrophobic core of polymeric nanoparticles, AuNRs were coated with a thiolated fatty acid (12-mercaptododecanoic acid). The drug-loaded hybrid nanoparticles were prepared by the nanoprecipitation method, obtaining nanoparticles of about 200 nm and drug loadings of 9.0 and 5.4% w/w for sorafenib and lenvatinib, respectively. These multifunctional nanosystems have shown to convert NIR radiation into heat and release charged drugs in a remote-controlled manner. Then, the biocompatibility and synergistic effects of a chemo-phototherapy combination, as well the receptor-mediated internalization, were evaluated by an in vitro test on HepG2, HuH7, and NHDF. The results indicate that the proposed nanoparticles can be considered to be virtuous candidates for an efficient and selective dual-mode therapy of hepatocarcinoma.

Multifunctional Lipid-Based Nanoparticles for Codelivery of Anticancer Drugs and siRNA for Treatment of Non-Small Cell Lung Cancer with Different Level of Resistance and EGFR Mutations

Resistance to chemotherapy, enhanced proliferation, invasion, angiogenesis, and metastasis (RPIAM) represent major obstacles that limit the efficacy of cancer treatment especially in advanced stages of cancer. Overcoming or suppressing RPIAM can dramatically improve the treatment outcome. Non-small cell lung cancer (NSCLC) is frequently diagnosed in an advanced stage and often possesses intrinsic resistance to chemotherapy accompanied by the fast development of acquired resistance during the treatment. Oncogenic receptor tyrosine kinases (TKs), specifically epidermal growth factor (EGF) TKs, play an important role in the activation of MAPK/PI3K/Akt/STAT pathways, finally leading to the development of RPIAM. However, the suppression of EGF-TK by different drugs is limited by various defensive mechanisms and mutations. In order to effectively prevent the development of RPIAM in NSCLC, we formulated and tested a multicomponent and multifunctional cancer targeted delivery system containing Nanostructured Lipid Carriers (NLCs) as vehicles, luteinizing hormone release hormone (LHRH) as a cancer targeting moiety, EFG-TK inhibitor gefitinib and/or paclitaxel as anticancer drug(s), siRNA targeted to EGF receptor (EGFR) mRNA as a suppressor of EGF receptors, and an imaging agent (rhodamine) for the visualization of cancer cells. Experimental data obtained show that this complex delivery system possesses significantly enhanced anticancer activity that cannot be achieved by individual components applied separately.

Multifunctional and stimuli-responsive nanocarriers for targeted therapeutic delivery

INTRODUCTION

Nanocarrier-based delivery systems offer multiple benefits to overcome limitations of the traditional drug dosage forms, such as protection of the drug, enhanced bioavailability, targeted delivery to disease site, etc. Nanocarriers have exhibited tremendous successes in targeted delivery of therapeutics to the desired tissues and cells with improved bioavailability, high drug loading capacity, enhanced intracellular delivery, and better therapeutic effect. A specific design of stimuli-responsive nanocarriers allows for changing their structural and physicochemical properties in response to exogenous and endogenous stimuli. These nanocarriers show a promise in site specific controlled release of therapeutics under certain physiological conditions or external stimuli.

AREAS COVERED

This review highlights recent progresses on the multifunctional and stimuli-sensitive nanocarriers for targeted therapeutic drug delivery applications.

EXPERT OPINION

The progress from single functional to multifunctional nanocarriers has shown tremendous potential for targeted delivery of therapeutics. On our opinion, the future of targeted delivery of drugs, nucleic acids, and other substances belongs to the site-targeted multifunctional and stimuli-based nanoparticles with controlled release. Targeting of nanocarriers to the disease site enhance the efficacy of the treatment by delivering more therapeutics specifically to the affected cells and substantially limiting adverse side effects upon healthy organs, tissues, and cells.

Ultra-small lipid nanoparticles encapsulating sorafenib and midkine-siRNA selectively-eradicate sorafenib-resistant hepatocellular carcinoma in vivo

Hepatocellular carcinoma (HCC) is a fatal disease with limited therapeutic choices. The stroma-rich tumor microenvironment hinders the in vivo delivery of most nanomedicines. Ultra-small lipid nanoparticles (usLNPs) were designed for the selective co-delivery of the cytotoxic drug, sorafenib (SOR), and siRNA against the Midkine gene (MK-siRNA) to HCC in mice. The usLNPs composed of a novel pH-sensitive lipid, a diversity of phospholipids and a highly-selective targeting peptide. A microfluidic device, iLiNP, was used and a variety of factors were controlled to tune particle size aiming at maximizing tumor penetration efficiency. Optimizing the composition and physico-chemical properties of the usLNPs resulted in an enhanced tumor accumulation, selectivity and in vivo gene silencing. The optimized usLNPs exerted potent gene silencing in the tumor (median effective dose, ED₅₀~0.1 mg/Kg) with limited effect on the healthy liver. The novel combination synergistically-eradicated HCC in mice (~85%) at a surprisingly-low dose of SOR (2.5 mg/Kg) which could not be achieved via individual monotherapy. Toxicity studies revealed the biosafety of the usLNPs upon either acute or chronic treatment. Furthermore, the SOR-resistant HCC established in mice was eradicated by 70% using this approach. We conclude that our strategy is promising for potential clinical applications in HCC treatment.

Tumor-Targeted Dendrimer Nanoparticles for Combinatorial Delivery of siRNA and Chemotherapy for Cancer Treatment

In current cancer therapy, the combined targeted delivery of treatments is an important method to enhance the therapeutic efficiency and reduce adverse side effects. Dendrimer-based nanoparticles have received considerable attention for multifunctional therapeutic delivery. In this chapter, we describe the methods for encapsulating the chemotherapeutic drug, cisplatin (CDDP), and human antigen R (HuR)-targeted siRNA into dendrimer nanoparticles for folate receptor-targeted delivery. We discuss the methodologies for physical and biological characterization of synthesized multifunctional (Den-PEI-CDDP-HuR-FA) nanoparticles in detail. Physical characterization includes size and charge determination, drug encapsulation and release kinetics, ligand conjugation, etc., and functional characterization involves testing of the nanoparticles for receptor-specific uptake and cytotoxicity on human lung cancer and normal cells. The protocol provided is geared to provide the readers an overview of developing multifunctional dendrimer-based nanoparticles. However, based on the individual's objective and the type of combinatorial drugs to deliver, the protocol may need modifications in achieving maximal efficacy.

Strategy to enhance lung cancer treatment by five essential elements: inhalation delivery, nanotechnology, tumor-receptor targeting, chemo- and gene therapy

Non-Small Cell Lung Carcinoma (NSCLC), is the most common type of lung cancer (more than 80% of all cases). Small molecule Tyrosine Kinase (TK) Inhibitors acting on the Epidermal Growth Factor Receptors (EGFRs) are standard therapies for patients with NSCLC harboring EGFR-TK inhibitor-sensitizing mutations. However, fewer than 10 % of patients with NSCLC benefit from this therapy. Moreover, even the latest generation of EGFR inhibitors can cause severe systemic toxicities and are ineffective in preventing non-canonical EGFR signaling. In order to minimize and even overcome these limitations, we are proposing a novel multi-tier biotechnology treatment approach that includes: (1) suppression of all four types of EGFR-TKs by a pool of small interfering RNAs (siRNAs); (2) induction of cell death by an anticancer drug, (3) enhancing the efficiency of the treatment by the local inhalation delivery of therapeutic agents directly to the lungs (passive targeting), (4) active receptor-mediated targeting of the therapy specifically to cancer cells that in turn should minimize adverse side effects of treatment and (5) increasing the stability, solubility, and cellular penetration of siRNA and drug by using tumor targeted Nanostructured Lipid Carriers (NLC). Methods: NLCs targeted to NSCLC cells by a synthetic Luteinizing Hormone-Releasing Hormone (LHRH) decapeptide was used for the simultaneous delivery of paclitaxel (TAX) and a pool of siRNAs targeted to the four major forms of EGFR-TKs. LHRH-NLC-siRNAs-TAX nanoparticles were synthesized, characterized and tested in vitro using human lung cancer cells with different sensitivities to gefitinib (inhibitor of EGFR) and in vivo on an orthotopic NSCLC mouse model. Results: Proposed nanoparticle-based complex containing an anticancer drug, inhibitors of different types of EGFR-TKs and peptide targeted to the tumor-specific receptors (LHRH-NLC-siRNAs-TAX) demonstrated a favorable organ distribution and superior anticancer effect when compared with treatment by a single drug, inhibitor of one EGFR-TK and non-targeted therapy. Conclusions: The use of a multifunctional NLC-based delivery system substantially enhanced the efficiency of therapy for NSCLC and possibly will limit adverse side effects of the treatments. The results obtained have the potential to significantly impact the field of drug delivery and to improve the efficiency of therapy of lung and other types of cancer.

Nanocarrier-based systems for targeted and site specific therapeutic delivery

Systemic drug delivery methods such as oral or parenteral administration of free drugs possess relatively low treatment efficiency and marked adverse side effects. The use of nanoparticles for drug delivery in most cases substantially enhances drug efficacy, improves pharmacokinetics and drug release and limits their side effects. However, further enhancement in drug efficacy and significant limitation of adverse side effects can be achieved by specific targeting of nanocarrier-based delivery systems especially in combination with local administration. The present review describes major advantages and limitations of organic and inorganic nanocarriers or living cell-based drug and nucleic acid delivery systems. Among these, different nanoparticles, supramolecular gels, therapeutic cells as living drug carriers etc. have emerged as a new frontier in modern medicine.

Inhalation treatment of cystic fibrosis with lumacaftor and ivacaftor co-delivered by nanostructured lipid carriers

Cystic fibrosis (CF), a most deadly genetic disorder, is caused by mutations of CF transmembrane receptor (CFTR) - a chloride channel present at the surface of epithelial cells. In general, two steps have to be involved in treatment of the disease: correction of cellular defects and potentiation to further increase channel opening. Consequently, a combinatorial simultaneous treatment with two drugs with different mechanisms of action, lumacaftor and ivacaftor, has been recently proposed. While lumacaftor is used to correct p.Phe508del mutation (the loss of phenylalanine at position 508) and increase the amount of cell surface-localized CFTR protein, ivacaftor serves as a CFTR potentiator that increases the open probability of CFTR channels. Since the main organ that is affected by cystic fibrosis is the lung, the delivery of drugs directly to the lungs by inhalation has a potential to enhance the efficacy of the treatment of CF and limit adverse side effects upon healthy tissues and organs. Based on our extensive experience in inhalation delivering of drugs by different nanocarriers, we selected nanostructured lipid carriers (NLC) for the delivery both drugs directly to the lungs by inhalation and tested NLC loaded with drugs in vitro (normal and CF human bronchial epithelial cells) and in vivo (homozygote/homozygote bi-transgenic mice with CF). The results show that the designed NLCs demonstrated a high drug loading efficiency and were internalized in the cytoplasm of CF cells. It was found that NLC-loaded drugs were able to restore the expression and function of CFTR protein. As a result, the combination of lumacaftor and ivacaftor delivered by lipid nanoparticles directly into the lungs was highly effective in treating lung manifestations of cystic fibrosis.

Recent Progress in Gene Therapy for Ovarian Cancer

Ovarian cancer is the most lethal gynecological malignancy in developed countries. This is due to the lack of specific symptoms that hinder early diagnosis and to the high relapse rate after treatment with radical surgery and chemotherapy. Hence, novel therapeutic modalities to improve clinical outcomes in ovarian malignancy are needed. Progress in gene therapy has allowed the development of several strategies against ovarian cancer. Most are focused on the design of improved vectors to enhance gene delivery on the one hand, and, on the other hand, on the development of new therapeutic tools based on the restoration or destruction of a deregulated gene, the use of suicide genes, genetic immunopotentiation, the inhibition of tumour angiogenesis, the alteration of pharmacological resistance, and oncolytic virotherapy. In the present manuscript, we review the recent advances made in gene therapy for ovarian cancer, highlighting the latest clinical trials experience, the current challenges and future perspectives.

Nanomedicine of synergistic drug combinations for cancer therapy - Strategies and perspectives

Nanomedicine of synergistic drug combinations has shown increasing significance in cancer therapy due to its promise in providing superior therapeutic benefits to the current drug combination therapy used in clinical practice. In this article, we will examine the rationale, principles, and advantages of applying nanocarriers to improve anticancer drug combination therapy, review the use of nanocarriers for delivery of a variety of combinations of different classes of anticancer agents including small molecule drugs and biologics, and discuss the challenges and future perspectives of the nanocarrier-based combination therapy. The goal of this review is to provide better understanding of this increasingly important new paradigm of cancer treatment and key considerations for rational design of nanomedicine of synergistic drug combinations for cancer therapy.

Precision targeted therapy of ovarian cancer

The review is aimed at describing modern approaches to detection as well as precision and personalized treatment of ovarian cancer. Modern methods and future directions of nanotechnology-based targeted and personalized therapy are discussed.

Targeted expression of BikDD combined with metronomic doxorubicin induces synergistic antitumor effect through Bax activation in hepatocellular carcinoma

Conventional chemotherapy is commonly used to treat advanced non-resectable hepatocellular carcinoma (HCC) but this treatment modality has not demonstrated convincing survival benefit in HCC patients. Our previous studies indicated that targeted expression of therapeutic BikDD driven by a liver cancer-specific α-fetoprotein promoter/enhancer (eAFP) in the VISA backbone (eAFP-VISA-BikDD) significantly and specifically kills HCC cells in multiple orthotopic animal models. To enhance its therapeutic efficacy, we combined eAFP-VISA-BikDD with chemotherapeutic agents and found that eAFP-VISA-BikDD plus doxorubicin (Dox) or 5-fluorouracil (5-FU) demonstrated synergistic cytotoxicity in HCC cells. Specifically, the combination of eAFP-VISA-BikDD plus Dox markedly induced apoptosis via increased Bax mitochondrial translocation and cytoplasmic cytochrome c release. Compared with either agent alone, a low dose of Dox combined with eAFP-VISA-BikDD induced better antitumor effect and prolonged longer survival of mice in two orthotopic liver cancer xenograft models. Our findings provide strong preclinical support for evaluating the combined therapy of eAFP-VISA-BikDD and Dox in a clinical setting as a treatment option for HCC.

Recent Developments in Active Tumor Targeted Multifunctional Nanoparticles for Combination Chemotherapy in Cancer Treatment and Imaging

Nanotechnology and combination therapy are two major fields that show great promise in the treatment of cancer. The delivery of drugs via nanoparticles helps to improve drug's therapeutic effectiveness while reducing adverse side effects associated wifh high dosage by improving their pharmacokinetics. Taking advantage of molecular markers over-expressing on tumor tissues compared to normal cells, an "active" molecular marker targeted approach would be-beneficial for cancer therapy. These actively targeted nanoparticles would increase drug concentration at the tumor site, improving efficacy while further reducing chemo-resistance. The multidisciplinary approach may help to improve the overall efficacy in cancer therapy. This review article summarizes recent developments of targeted multifunctional nanoparticles in the delivery, of various drugs for a combinational chemotherapy approach to cancer treatment and imaging.

Stem cell-based gene therapy activated using magnetic hyperthermia to enhance the treatment of cancer

Stem cell-based gene therapies, wherein stem cells are genetically engineered to express therapeutic molecules, have shown tremendous potential for cancer applications owing to their innate ability to home to tumors. However, traditional stem cell-based gene therapies are hampered by our current inability to control when the therapeutic genes are actually turned on, thereby resulting in detrimental side effects. Here, we report the novel application of magnetic core-shell nanoparticles for the dual purpose of delivering and activating a heat-inducible gene vector that encodes TNF-related apoptosis-inducing ligand (TRAIL) in adipose-derived mesenchymal stem cells (AD-MSCs). By combining the tumor tropism of the AD-MSCs with the spatiotemporal MCNP-based delivery and activation of TRAIL expression, this platform provides an attractive means with which to enhance our control over the activation of stem cell-based gene therapies. In particular, we found that these engineered AD-MSCs retained their innate ability to proliferate, differentiate, and, most importantly, home to tumors, making them ideal cellular carriers. Moreover, exposure of the engineered AD-MSCS to mild magnetic hyperthermia resulted in the selective expression of TRAIL from the engineered AD-MSCs and, as a result, induced significant ovarian cancer cell death in vitro and in vivo.

Nanotechnology approaches for inhalation treatment of lung diseases

Local administration of therapeutics by inhalation for treatment of lung diseases has the ability to deliver drugs, nucleic acids and peptides specifically to the site of their action and therefore enhance the efficacy of the treatment, limit the penetration of nebulized therapeutic agent(s) into the bloodstream and consequently decrease adverse systemic side effects of the treatment. Nanotechnology allows for a further enhancement of the treatment efficiency. The present review analyzes modern therapeutic approaches of inhaled nanoscale-based pharmaceutics for the detection and treatment of various lung diseases.

Tumor-targeted responsive nanoparticle-based systems for magnetic resonance imaging and therapy

Purpose

Design and synthesis of a tumor responsive nanoparticle-based system for imaging and treatment of various cancers.

Methods

Manganese oxide nanoparticles (Mn₃O₄ NPs) were synthesized and modified with LHRH targeting peptide or anti-melanoma antibodies (cancer targeting moieties) and a MMP2 cleavable peptide (a possible chemotactic factor). Nanostructured lipid carriers (NLCs) were used to entrap the BRAF inhibitor, vemurafenib, and enhance cytotoxicity of the drug. Size distribution, stability, drug entrapment, cytotoxicity and genotoxicity of synthesized nanoparticles were studied in vitro. Enhancement of MRI signal by nanoparticles and their body distribution were examined in vivo on mouse models of melanoma, ovarian and lung cancers.

Results

Uniform, stable cancer-targeted nanoparticles (PEGylated water-soluble Mn₃O₄ NPs and NLCs) were synthesized. No signs of cyto-,genotoxicity and DNA damage were detected for nanoparticles that do not contain an anticancer drug. Entrapment of vemurafenib into nanoparticles significantly enhanced drug toxicity in cancer cells with targeted V600E mutation. The developed nanoparticles containing LHRH and MMP2 peptides showed preferential accumulation in primary and metastatic tumors increasing the MRI signal in mice with melanoma, lung and ovarian cancers.

Conclusions

The proposed nanoparticle-based systems provide the foundation for building an integrated MRI diagnostic and therapeutic approach for various types of cancer.

Inhalation treatment of lung cancer: the influence of composition, size and shape of nanocarriers on their lung accumulation and retention

Objective

Various nanoparticles have been designed and tested in order to select optimal carriers for the inhalation delivery of anticancer drugs to the lungs.

Methods

The following nanocarriers were studied: micelles, liposomes, mesoporous silica nanoparticles (MSNs), poly propyleneimine (PPI) dendrimer-siRNA complexes nanoparticles, quantum dots (QDs), and poly (ethylene glycol) polymers. All particles were characterized using the following methods: dynamic light scattering, zeta potential, atomic force microscopy, in vitro cyto- and genotoxicity. In vivo organ distribution of all nanoparticles, retention in the lungs, and anticancer effects of liposomes loaded with doxorubicin were examined in nude mice after the pulmonary or intravenous delivery.

Results

Significant differences in lung uptake were found after the inhalation delivery of lipid-based and non-lipid-based nanoparticles. The accumulation of liposomes and micelles in lungs remained relatively high even 24 h after inhalation when compared with MSNs, QDs, and PPI dendrimers. There were notable differences between nanoparticle accumulation in the lungs and other organs 1 and 3 h after inhalation or intravenous administrations, but 24 h after intravenous injection all nanoparticles were mainly accumulated in the liver, kidneys, and spleen. Inhalation delivery of doxorubicin by liposomes significantly enhanced its anticancer effect and prevented severe adverse side effects of the treatment in mice bearing the orthotopic model of lung cancer.

Conclusion

The results of the study demonstrate that lipid-based nanocarriers had considerably higher accumulation and longer retention time in the lungs when compared with non-lipid-based carriers after the inhalation delivery. These particles are most suitable for effective inhalation treatment of lung cancer.

Plasmid DNA hydrogels for biomedical applications

In the last few years, our research group has focused on the design and development of plasmid DNA (pDNA) based systems as devices to be used therapeutically in the biomedical field. Biocompatible macro and micro plasmid DNA gels were prepared by a cross-linking reaction. For the first time, the pDNA gels have been investigated with respect to their swelling in aqueous solution containing different additives. Furthermore, we clarified the fundamental and basic aspects of the solute release mechanism from pDNA hydrogels and the significance of this information is enormous as a basic tool for the formulation of pDNA carriers for drug/gene delivery applications. The co-delivery of a specific gene and anticancer drugs, combining chemical and gene therapies in the treatment of cancer was the main challenge of our research. Significant progresses have been made with a new p53 encoding pDNA microgel that is suitable for the loading and release of pDNA and doxorubicin. This represents a strong valuable finding in the strategic development of systems to improve cancer cure through the synergetic effect of chemical and gene therapy.

Magnetic mesoporous silica nanoparticles for potential delivery of chemotherapeutic drugs and hyperthermia

Magnetic mesoporous silica (MMS) nanoparticles could provide a promising multifunctional platform for the combination of chemotherapy and hyperthermia.

Nanotechnology approaches for personalized treatment of multidrug resistant cancers

The efficacy of chemotherapy is substantially limited by the resistance of cancer cells to anticancer drugs that fluctuates significantly in different patients. Under identical chemotherapeutic protocols, some patients may receive relatively ineffective doses of anticancer agents while other individuals obtain excessive amounts of drugs that induce severe adverse side effects on healthy tissues. The current review is focused on an individualized selection of drugs and targets to suppress multidrug resistance. Such selection is based on the molecular characteristics of a tumor from an individual patient that can potentially improve the treatment outcome and bring us closer to an era of personalized medicine.

Toxicity and efficacy evaluation of multiple targeted polymalic acid conjugates for triple-negative breast cancer treatment

Engineered nanoparticles are widely used for delivery of drugs but frequently lack proof of safety for cancer patient's treatment. All-in-one covalent nanodrugs of the third generation have been synthesized based on a poly(β-L-malic acid) (PMLA) platform, targeting human triple-negative breast cancer (TNBC). They significantly inhibited tumor growth in nude mice by blocking synthesis of epidermal growth factor receptor, and α4 and β1 chains of laminin-411, the tumor vascular wall protein and angiogenesis marker. PMLA and nanodrug biocompatibility and toxicity at low and high dosages were evaluated in vitro and in vivo. The dual-action nanodrug and single-action precursor nanoconjugates were assessed under in vitro conditions and in vivo with multiple treatment regimens (6 and 12 treatments). The monitoring of TNBC treatment in vivo with different drugs included blood hematologic and immunologic analysis after multiple intravenous administrations. The present study demonstrates that the dual-action nanoconjugate is highly effective in preclinical TNBC treatment without side effects, supported by hematologic and immunologic assays data. PMLA-based nanodrugs of the Polycefin™ family passed multiple toxicity and efficacy tests in vitro and in vivo on preclinical level and may prove to be optimized and efficacious for the treatment of cancer patients in the future.

Targeted nanomedicine for suppression of CD44 and simultaneous cell death induction in ovarian cancer: an optimal delivery of siRNA and anticancer drug

PURPOSE

The proposed project is aimed at enhancing the efficiency of epithelial ovarian cancer treatment and reducing adverse side effects of chemotherapy using nanotechnology. Overexpression of the CD44 membrane receptor results in tumor initiation, growth, cancer stem cells' specific behavior, development of drug resistance, and metastases. We hypothesize that a developed cancer-targeted delivery system that combines CD44 siRNA with paclitaxel would successfully deliver its payload inside cancer cells, effectively induce cell death, and prevent metastases.

EXPERIMENTAL DESIGN

We synthesized, characterized, and tested a nanoscale-based drug delivery system (DDS) containing a modified polypropylenimine (PPI) dendrimer as a carrier; anticancer drug paclitaxel as a cell death inducer; a synthetic analog of luteinizing hormone-releasing hormone (LHRH) peptide as a tumor-targeting moiety; and siRNA targeted to CD44 mRNA. The proposed DDS was tested in vitro and in vivo using metastatic ovarian cancer cells isolated from patients with malignant ascites.

RESULTS

We found that in contrast with cells isolated from primary tumors, CD44 was highly overexpressed in metastatic cancer cells. Treatment with the proposed tumor-targeted nanoscale-based nucleic acid and DDS led to the suppression of CD44 mRNA and protein, efficient induction of cell death, effective tumor shrinkage, and prevention of adverse side effects on healthy organs.

CONCLUSION

We show a high therapeutic potential for combinatorial treatment of ovarian carcinoma with a novel DDS that effectively transports siRNA targeting to CD44 mRNA simultaneously with cytotoxic agents. Clin Cancer Res; 19(22); 6193-204. ©2013 AACR.

Docetaxel-loaded liposomes: preparation, pH sensitivity, pharmacokinetics, and tissue distribution

Docetaxel (DTX), as a member of taxoid family, has been widely used in the treatment of cancers. The present study prepared pH-sensitive DTX-loaded liposomes (DTX-Lips) by thin-film dispersion method and various physico-chemical and morphological properties were examined. The pH sensitivity of in vitro DTX release and the in vivo pharmacokinetics and tissue distribution using Kunming mice were also investigated. The mean particle size and zeta potential of DTX liposomes were (277±2) nm and (-32.60±0.26) mV, respectively. Additionally, in vitro drug release study showed that the cumulative release rate was 1.3 times more at pH 5.0 than at pH 7.4, suggesting a pH-dependent release ability of DTX-Lips. Pharmacokinetic and pharmaceutical studies in comparison with Duopafei(®) showed that the half-time period (t(1/2)) and area under the curve (AUC) of DTX-Lips in mouse plasma were 1.8 times longer and 2.6 times higher, respectively, and that DTX-Lips selectively accumulated in macrophage-rich organs such as liver and spleen. These results together suggest that the DTX-Lips could be a promising formulation for the clinical administration of DTX.

Nanostructured lipid carriers as multifunctional nanomedicine platform for pulmonary co-delivery of anticancer drugs and siRNA

We developed, synthesized, and tested a multifunctional nanostructured lipid nanocarrier-based system (NLCS) for efficient delivery of an anticancer drug and siRNA directly into the lungs by inhalation. The system contains: (1) nanostructured lipid carriers (NLC); (2) anticancer drug (doxorubicin or paclitaxel); (3) siRNA targeted to MRP1 mRNA as a suppressor of pump drug resistance; (4) siRNA targeted to BCL2 mRNA as a suppressor of nonpump cellular resistance and (5) a modified synthetic analog of luteinizing hormone-releasing hormone (LHRH) as a targeting moiety specific to the receptors that are overexpressed in the plasma membrane of lung cancer cells. The NLCS was tested in vitro using human lung cancer cells and in vivo utilizing mouse orthotopic model of human lung cancer. After inhalation, the proposed NLCS effectively delivered its payload into lung cancer cells leaving healthy lung tissues intact and also significantly decreasing the exposure of healthy organs when compared with intravenous injection. The NLCS showed enhanced antitumor activity when compared with intravenous treatment. The data obtained demonstrated high efficiency of proposed NLCS for tumor-targeted local delivery by inhalation of anticancer drugs and mixture of siRNAs specifically to lung cancer cells and, as a result, efficient suppression of tumor growth and prevention of adverse side effects on healthy organs.

Recent trends in multifunctional liposomal nanocarriers for enhanced tumor targeting

Liposomes are delivery systems that have been used to formulate a vast variety of therapeutic and imaging agents for the past several decades. They have significant advantages over their free forms in terms of pharmacokinetics, sensitivity for cancer diagnosis and therapeutic efficacy. The multifactorial nature of cancer and the complex physiology of the tumor microenvironment require the development of multifunctional nanocarriers. Multifunctional liposomal nanocarriers should combine long blood circulation to improve pharmacokinetics of the loaded agent and selective distribution to the tumor lesion relative to healthy tissues, remote-controlled or tumor stimuli-sensitive extravasation from blood at the tumor's vicinity, internalization motifs to move from tumor bounds and/or tumor intercellular space to the cytoplasm of cancer cells for effective tumor cell killing. This review will focus on current strategies used for cancer detection and therapy using liposomes with special attention to combination therapies.