Cytotoxicity of PEGylated liposomes co-loaded with novel pro-apoptotic drug NCL-240 and the MEK inhibitor cobimetinib against colon carcinoma in vitro

Enhancing the efficacy of letrozole-loaded PEGylated nanoliposomes against breast cancer cells: In vitro study

Considering its overall impact on human health, letrozole (Let) has been described as having significant efficacy that could be improved by developing drug delivery systems. Considering the side effects of Let, this study aims to encapsulate Let in liposomes and PEGylated liposome nanoparticles (Lipo-Let-PEG) and evaluate the cytotoxic effects on the MCF-7 breast cancer cell line. For this purpose, the Lipo-Let-PEG formulation was designed and characterized by SEM, DLS, and FTIR methods, and the drug release from the optimized formulation and the stability of the optimized Lipo-Let-PEG were measured. Furthermore, the cytotoxicity and apoptotic studies were performed using MTT assay and flow cytometric analysis. According to the experimental data, the vesicle size and EE% were 170.05 ± 4.15 nm and 87.21 ± 1.36 %, respectively. The cumulative release from Lipo-Let-PEG at pH 5.4 and 7.4 was also approximately 60 % and 50 %, respectively. MTT results showed that Lip-Let-PEG produced more drug cytotoxicity than Lip-Let against MCF-7 cancer cells and was more compatible with normal cells. The results of apoptosis and cell cycle arrest using flow cytometry show that Lipo-Let-PEG caused the most significant increase in apoptotic rates and cell cycle arrest in cancer cells compared to other treated groups. In conclusion, Lipo-Let-PEG can be used as an anticancer agent by arresting cell cycle progression and inducing apoptosis, which can be applied in future studies to prevent breast cancer development.

Targeting RAF dimers in RAS mutant tumors: From biology to clinic

RAS mutations occur in approximately 30% of tumors worldwide and have a poor prognosis due to limited therapies. Covalent targeting of KRAS G12C has achieved significant success in recent years, but there is still a lack of efficient therapeutic approaches for tumors with non-G12C KRAS mutations. A highly promising approach is to target the MAPK pathway downstream of RAS, with a particular focus on RAF kinases. First-generation RAF inhibitors have been authorized to treat BRAF mutant tumors for over a decade. However, their use in RAS-mutated tumors is not recommended due to the paradoxical ERK activation mainly caused by RAF dimerization. To address the issue of RAF dimerization, type II RAF inhibitors have emerged as leading candidates. Recent clinical studies have shown the initial effectiveness of these agents against RAS mutant tumors. Promisingly, type II RAF inhibitors in combination with MEK or ERK inhibitors have demonstrated impressive efficacy in RAS mutant tumors. This review aims to clarify the importance of RAF dimerization in cellular signaling and resistance to treatment in tumors with RAS mutations, as well as recent progress in therapeutic approaches to address the problem of RAF dimerization in RAS mutant tumors.

Nanoparticles in Medicine: Current Status in Cancer Treatment

Cancer is still a leading cause of deaths worldwide, especially due to those cases diagnosed at late stages with metastases that are still considered untreatable and are managed in such a way that a lengthy chronic state is achieved. Nanotechnology has been acknowledged as one possible solution to improve existing cancer treatments, but also as an innovative approach to developing new therapeutic solutions that will lower systemic toxicity and increase targeted action on tumors and metastatic tumor cells. In particular, the nanoparticles studied in the context of cancer treatment include organic and inorganic particles whose role may often be expanded into diagnostic applications. Some of the best studied nanoparticles include metallic gold and silver nanoparticles, quantum dots, polymeric nanoparticles, carbon nanotubes and graphene, with diverse mechanisms of action such as, for example, the increased induction of reactive oxygen species, increased cellular uptake and functionalization properties for improved targeted delivery. Recently, novel nanoparticles for improved cancer cell targeting also include nanobubbles, which have already demonstrated increased localization of anticancer molecules in tumor tissues. In this review, we will accordingly present and discuss state-of-the-art nanoparticles and nano-formulations for cancer treatment and limitations for their application in a clinical setting.

Nanoparticle drug delivery systems for synergistic delivery of tumor therapy

Nanoparticle drug delivery systems have proved anti-tumor effects; however, they are not widely used in tumor therapy due to insufficient ability to target specific sites, multidrug resistance to anti-tumor drugs, and the high toxicity of the drugs. With the development of RNAi technology, nucleic acids have been delivered to target sites to replace or correct defective genes or knock down specific genes. Also, synergistic therapeutic effects can be achieved for combined drug delivery, which is more effective for overcoming multidrug resistance of cancer cells. These combination therapies achieve better therapeutic effects than delivering nucleic acids or chemotherapeutic drugs alone, so the scope of combined drug delivery has also been expanded to three aspects: drug-drug, drug-gene, and gene-gene. This review summarizes the recent advances of nanocarriers to co-delivery agents, including i) the characterization and preparation of nanocarriers, such as lipid-based nanocarriers, polymer nanocarriers, and inorganic delivery carriers; ii) the advantages and disadvantages of synergistic delivery approaches; iii) the effectual delivery cases that are applied in the synergistic delivery systems; and iv) future perspectives in the design of nanoparticle drug delivery systems to co-deliver therapeutic agents.

Current Progress in Cancer Treatment Using Nanomaterials

The pathological processes of cancer are complex. Current methods used for chemotherapy have various limitations, such as cytotoxicity, multi-drug resistance, stem-like cells growth, and lack of specificity. Several types of nanomaterials are used for cancer treatment. Nanomaterials 1–100 nm in size have special optical, magnetic, and electrical characteristics. Nanomaterials have been fabricated for cancer treatments to overcome cytotoxicity and low specificity, and improve drug capacity and bioavailability. Despite the increasing number of related studies, few nanodrugs have been approved for clinical use. To improve translation of these materials, studies of targeted drug delivery using nanocarriers are needed. Cytotoxicity, enhanced permeability and retention effects, and the protective role of the protein corona remain to be addressed. This mini-review summarizes new nanomaterials manufactured in studies and in clinical use, analyses current barriers preventing their translation to clinical use, and describes the effective application of nanomaterials in cancer treatment.

Transferrin receptor-mediated liposomal drug delivery: recent trends in targeted therapy of cancer

INTRODUCTION

Compared to normal cells, malignant cancer cells require more iron for their growth and rapid proliferation, which can be supplied by a high expression level of transferrin receptor (TfR). It is well known that the expression of TfR on the tumor cells is considerably higher than that of normal cells, which makes TfR an attractive target in cancer therapy.

AREAS COVERED

In this review, the primary focus is on the role of TfR as a valuable tool for cancer-targeted drug delivery, followed by the full coverage of available TfR ligands and their conjugation chemistry to the surface of liposomes. Finally, the most recent studies investigating the potential of TfR-targeted liposomes as promising drug delivery vehicles to different cancer cells are highlighted with emphasis on their improvement possibilities to become a part of future cancer medicines.

EXPERT OPINION

Liposomes as a valuable class of nanocarriers have gained much attention toward cancer therapy. From all the studies that have exploited the therapeutic and diagnostic potential of TfR on cancer cells, it can be realized that the systematic assessment of TfR ligands applied for liposomal targeted delivery has yet to be entirely accomplished.

Comparison of three synthetic transferrin mimetic small peptides to promote the blood-brain barrier penetration of vincristine liposomes for improved glioma targeted therapy

The existence of the blood-brain barrier (BBB) makes the clinical chemotherapy of glioma a formidable challenge, because it hinders the passage of different chemotherapeutics into the brain and reduces the overall therapeutic efficiency. Therefore, it is necessary to design a drug delivery system in way that would favor the transportation of anti-cancer agents across the BBB and increase their selective accumulation within the tumor cells without affecting the normal tissues. Transferrin receptor (TfR) that shows an elevated level of expression on the BBB and glioma cells emerges as a promising tool for brain targeted delivery and glioma therapy. However, only a limited number of studies have comparatively evaluated the functionally of TfR targeting ligands. Herein, a series of liposomal formulations modified with the most well-known TfR targeting peptides including T12 (also known as THR), B6, and T7 was developed and their brain targeting capability and selective glioma accumulation was comparatively evaluated in vitro and in vivo. Among all TfR targeting or non-targeting groups, T7-modified liposomes (T7-LS) showed the highest BBB penetration capacity and brain distribution and displayed an enhanced accumulation in glioma cells. When loaded with vincristine (VCR), as a model chemotherapeutic, T7-LS/VCR could achieve the best anti-glioma outcome by means of targeted cytotoxicity and apoptosis in vitro. The obtained results suggested T7-LS as a potential platform for effective brain targeted delivery and glioma therapy in clinic.

Nanomaterials for cancer therapy: current progress and perspectives

Cancer is a disease with complex pathological process. Current chemotherapy faces problems such as lack of specificity, cytotoxicity, induction of multi-drug resistance and stem-like cells growth. Nanomaterials are materials in the nanorange 1–100 nm which possess unique optical, magnetic, and electrical properties. Nanomaterials used in cancer therapy can be classified into several main categories. Targeting cancer cells, tumor microenvironment, and immune system, these nanomaterials have been modified for a wide range of cancer therapies to overcome toxicity and lack of specificity, enhance drug capacity as well as bioavailability. Although the number of studies has been increasing, the number of approved nano-drugs has not increased much over the years. To better improve clinical translation, further research is needed for targeted drug delivery by nano-carriers to reduce toxicity, enhance permeability and retention effects, and minimize the shielding effect of protein corona. This review summarizes novel nanomaterials fabricated in research and clinical use, discusses current limitations and obstacles that hinder the translation from research to clinical use, and provides suggestions for more efficient adoption of nanomaterials in cancer therapy.

Liposomal Nanostructures for Drug Delivery in Gastrointestinal Cancers

Gastrointestinal (GI) cancers like liver, pancreatic, colorectal, and gastric cancer remain some of the most difficult and aggressive cancers. Nanoparticles like liposomes had been approved in the clinic for cancer therapy dating as far back as 1995. Over the years, liposomal formulations have come a long way, facing several roadblocks and failures, and advancing by optimizing formulations and incorporating novel design approaches to navigate therapeutic delivery challenges. The first liposomal formulation for a GI cancer drug was approved recently in 2015, setting the stage for further clinical developments of liposome-based delivery systems for therapies against GI malignancies. This article reviews the design considerations and strategies that can be used to deliver drugs to GI tumors, the wide range of therapeutic agents that have been explored in preclinical as well as clinical studies, and the current therapies that are being investigated in the clinic against GI malignancies.

Multi-targeted approach by 2-benzimidazolylquinoxalines-loaded cationic arginine liposomes against сervical cancer cells in vitro

Multi-targeted approaches for inhibition of сervical cancer cells in vitro were developed by implementing two different strategies and drug combination for creation of new therapeutic target agents and for nanotechnological-enhancement of intracellular delivery. New 2-benzimidazolylquinoxalines derivatives were synthesized and characterized by combining two different pharmacophores - benzimidazole and quinoxaline rings directly bonded in their structures. Spectrophotometric technique for determination of content of compounds in various media was developed to evaluate their solubility in water and micellar solutions of surfactants. The bioavailability of poorly water-soluble 2-benzimidazolylquinoxalines was improved by PEGylated liposomes as antitumor drug delivery carriers. 2-benzimidazolylquinoxalines-loaded PEGylated liposomes, with size close to 100 nm and negative zeta potential ranging from -13 mV to -27 mV, were time-stable at room temperature. The design of liposomal formulations for improving cellular uptake and in vitro antitumor efficacy was performed by modification of liposome surface with the new arginine surfactant. The cell viability of 2-benzimidazolylquinoxalines-loaded arginine liposomes on human cancer M-Hela cells was 16% at the concentration 0.15 mg/ml. Moreover, these liposomes showed a lower toxicity (40%) against normal human Gang liver cells both at the lowest and highest tested concentrations.

A novel strategy to achieve effective drug delivery: exploit cells as carrier combined with nanoparticles

Cell-mediated drug delivery systems employ specific cells as drug vehicles to deliver drugs to targeted sites. Therapeutics or imaging agents are loaded into these cells and then released in diseased sites. These specific cells mainly include red blood cells, leukocytes, stem cells and so on. The cell acts as a Trojan horse to transfer the drug from circulating blood to the diseased tissue. In such a system, these cells keep their original properties, which allow them to mimic the migration behavior of specific cells to carry drug to the targeted site after in vivo administration. This strategy elegantly combines the advantages of both carriers, i.e. the adjustability of nanoparticles (NPs) and the natural functions of active cells, which therefore provides a new perspective to challenge current obstacles in drug delivery. This review will describe a fundamental understanding of these cell-based drug delivery systems, and discuss the great potential of combinational application of cell carrier and NPs.

Applications of label-free, quantitative phase holographic imaging cytometry to the development of multi-specific nanoscale pharmaceutical formulations

A label-free, high content, time-lapse holographic imaging system was applied to studies in pharmaceutical compound development. Multiple fields of cellular images are obtained over typically several day evaluations within standard CO2 incubators. Events are segmented to obtain population data of cellular features, which are displayed in scattergrams and histograms. Cell tracking is accomplished, accompanied by Cartesian plots of cell movement, as well as plots of cell features vs. time in novel 4-D displays of X position, Y position, time, and cell thickness. Our review of the instrument validation data includes 1) tracking of Giant HeLa cells, which may be undergoing neosis, a process of tumor stem cell generation; 2) tracking the effects of cell cycle related toxic agents on cell lines; 3) using MicroRNAs to reverse the polarization state in macrophages to induce tumor cell killing; 4) development of liposomal nanoformulations to overcome Multi-Drug Resistance (MDR) in ovarian cancer cells; and 5) development of dual sensitive micelles to specifically target matrix metalloproteinase 2 (MMP2) over-expressing cell lines. © 2017 International Society for Advancement of Cytometry.

Protein-lipid nanohybrids as emerging platforms for drug and gene delivery: Challenges and outcomes

Nanoparticulate drug delivery systems have been long used to deliver a vast range of drugs and bioactives owing to their ability to demonstrate novel physical, chemical, and/or biological properties. An exponential growth has spurred in research and development of these nanocarriers which led to the evolution of a great number of diverse nanosystems including liposomes, nanoemulsions, solid lipid nanoparticles (SLNs), micelles, dendrimers, polymeric nanoparticles (NPs), metallic NPs, and carbon nanotubes. Among them, lipid-based nanocarriers have made the largest progress whether commercially or under development. Despite this progress, these lipid-based nanocarriers suffer from several limitations that led to the development of many protein-coated lipid nanocarriers. To less extent, protein-based nanocarriers suffer from limitations that led to the fabrication of some lipid bilayer enveloping protein nanocarriers. This review discusses in-depth some limitations associated with the lipid-based or protein-based nanocarriers and the fruitful outcomes brought by protein-lipid hybridization. Also discussed are the various hybridization techniques utilized to formulate these protein-lipid nanohybrids and the mechanisms involved in the drug loading process.

Reversal of Chemoresistance in Ovarian Cancer by Co-Delivery of a P-Glycoprotein Inhibitor and Paclitaxel in a Liposomal Platform

The overexpression of permeability-glycoprotein (P-gp), an ABC transporter involved in the cellular exclusion of chemotherapeutic drugs, is a major factor in paclitaxel-resistant ovarian cancer. However, in clinical trials, co-administration of P-gp inhibitors and anticancer drugs has not resulted in the efficient reversal of drug resistance. To improve administration, we encapsulated the third-generation P-gp inhibitor tariquidar (XR-9576, XR), alone or in combination with paclitaxel (PCT) in liposomes (LP). After optimization, the liposomes demonstrated favorable physicochemical properties and the ability to reverse chemoresistance in experiments using chemosensitive/chemoresistant ovarian cancer cell line pairs. Analyzing publicly available datasets, we found that overexpression of P-gp in ovarian cancer is associated with a shorter progression-free and overall survival. In vitro, LP(XR) significantly increased the cellular retention of rhodamine 123, a P-gp substrate. LP(XR,PCT) synergistically inhibited cell viability, blocked proliferation, and caused G₂-M arrest in paclitaxel-resistant SKOV3-TR and HeyA8-MDR cell lines overexpressing P-gp. Holographic imaging cytometry revealed that LP(XR,PCT) treatment of SKOV3-TR cells induced almost complete mitotic arrest, whereas laser scanning cytometry showed that the treatment induced apoptosis. In proof-of-concept preclinical studies, LP(XR,PCT), when compared with LP(PCT), significantly reduced tumor weight (43.2% vs. 16.9%, P = 0.0007) and number of metastases (44.4% vs. 2.8%, P = 0.012) in mice bearing orthotopic HeyA8-MDR ovarian tumors. In the xenografts, LP(XR,PCT) efficiently induced apoptosis and impaired proliferation. Our findings suggest that co-delivery of a P-gp inhibitor and paclitaxel using a liposomal platform can sensitize paclitaxel-resistant ovarian cancer cells to paclitaxel. LP(XR,PCT) should be considered for clinical testing in patients with P-gp-overexpressing tumors. Mol Cancer Ther; 15(10); 2282-93. ©2016 AACR.