Albumin nanocapsules containing fenretinide: pre-clinical evaluation of cytotoxic activity in experimental models of human non-small cell lung cancer

Attempts to Improve Lipophilic Drugs' Solubility and Bioavailability: A Focus on Fenretinide

The development of numerous drugs is often arrested at clinical testing stages, due to their unfavorable biopharmaceutical characteristics. It is the case of fenretinide (4-HPR), a second-generation retinoid, that demonstrated promising in vitro cytotoxic activity against several cancer cell lines. Unfortunately, response rates in early clinical trials with 4-HPR did not confirm the in vitro findings, mainly due to the low bioavailability of the oral capsular formulation that was initially developed. Capsular 4-HPR provided variable and insufficient drug plasma levels attributable to the high hepatic first-pass effect and poor drug water solubility. To improve 4-HPR bioavailability, several approaches have been put forward and tested in preclinical and early-phase clinical trials, demonstrating generally improved plasma levels and minimal systemic toxicities, but also modest antitumor efficacy. The challenge is thus currently still far from being met. To redirect the diminished interest of pharmaceutical companies toward 4-HPR and promote its further clinical development, this manuscript reviewed the attempts made so far by researchers to enhance 4-HPR bioavailability. A comparison of the available data was performed, and future directions were proposed.

Recent advancement on albumin nanoparticles in treating lung carcinoma

With the advancement of nanotechnology, many different forms of nanoparticles (NPs) are created, which specifically enhance anticancer drug delivery to tumor cells. Albumin bio-macromolecule is a flexible protein carrier for the delivery of drugs that is biodegradable, biocompatible, and non-toxic. As a result, it presents itself as an ideal material for developing nanoparticles for anticancer drug delivery. Toxicological investigations demonstrated that this novel drug delivery technique is safe for use in the human population. Furthermore, drug compatibility with the albumin nanoparticle is remarkable. The robust structure of the nanoparticle, high drug encapsulation, and customizable drug release make it a promising carrier option for the treatment of lung cancer. In this review, we summarize human serum albumin and bovine serum albumin in the targeted delivery of anticancer drugs to lung cancer cells.

Therapeutic strategies for non-small cell lung cancer: Experimental models and emerging biomarkers to monitor drug efficacies

While new targeted therapies have considerably changed the treatment and prognosis of non-small cell lung cancer (NSCLC), they are frequently unsuccessful due to primary or acquired resistances. Chemoresistance is a complex process that combines cancer cell intrinsic mechanisms including molecular and genetic abnormalities, aberrant interactions within the tumor microenvironment, and the pharmacokinetic characteristics of each molecule. From a pharmacological point of view, two levers could improve the response to treatment: (i) developing tools to predict the response to chemo- and targeted therapies and (ii) gaining a better understanding of the influence of the tumor microenvironment. Both personalized medicine approaches require the identification of relevant experimental models and biomarkers to understand and fight against chemoresistance mechanisms. After describing the main therapies in NSCLC, the scope of this review will be to identify and to discuss relevant in vitro and ex vivo experimental models that are able to mimic tumors. In addition, the interests of these models in the predictive responses to proposed therapies will be discussed. Finally, this review will evaluate the involvement of novel secreted biomarkers such as tumor DNA or micro RNA in predicting responses to anti-tumor therapies.

Current trends in the use of human serum albumin for drug delivery in cancer

INTRODUCTION

Human serum albumin is the most abundant transport protein in plasma, which has recently been extensively utilized to form nanoparticles for drug delivery in cancer. The primary reason for selecting albumin protein as drug delivery cargo is its excellent biocompatibility, biodegradability, and non-immunogenicity. Moreover, the albumin structure containing three homologous domains constituted of a single polypeptide (585 amino acid) incorporates various hydrophobic drugs by non-covalent interactions. Albumin shows active tumor targeting via their interaction with gp60 and SPARC proteins abundant in the tumor-associated endothelial cells and the tumor microenvironment.

AREAS COVERED

The review discusses the importance of albumin as a drug-carrier system, general procedures to prepare albumin NPs, and the current trends in using albumin-based nanomedicines to deliver various chemotherapeutic agents. The various applications of albumin in the nanomedicines, such as NPs surface modifier and fabrication of hybrid/active-tumor targeted NPs, are delineated based on current trends.

EXPERT OPINION

Nanomedicines have the potential to revolutionize cancer treatment. However, clinical translation is limited majorly due to the lack of suitable nanomaterials offering systemic stability, optimum drug encapsulation, tumor-targeted delivery, sustained drug release, and biocompatibility. The potential of albumin could be explored in nanomedicines fabrication for superior treatment outcomes in cancer.

Functionalized Liposome and Albumin-Based Systems as Carriers for Poorly Water-Soluble Anticancer Drugs: An Updated Review

Cancer is one of the leading causes of death worldwide. In the available treatments, chemotherapy is one of the most used, but has several associated problems, namely the high toxicity to normal cells and the resistance acquired by cancer cells to the therapeutic agents. The scientific community has been battling against this disease, developing new strategies and new potential chemotherapeutic agents. However, new drugs often exhibit poor solubility in water, which led researchers to develop functionalized nanosystems to carry and, specifically deliver, the drugs to cancer cells, targeting overexpressed receptors, proteins, and organelles. Thus, this review is focused on the recent developments of functionalized nanosystems used to carry poorly water-soluble drugs, with special emphasis on liposomes and albumin-based nanosystems, two major classes of organic nanocarriers with formulations already approved by the U.S. Food and Drug Administration (FDA) for cancer therapeutics.

Curcumin delivery by modified biosourced carbon-based nanoparticles

Aim: To prepare a novel hybrid system for the controlled release and delivery of curcumin (CUR). Methods: A method for the ultrasound-assisted fabrication of protein-modified nanosized graphene oxide-like carbon-based nanoparticles (CBNPs) was developed. After being modified with bovine serum albumin (BSA), CUR was loaded onto the synthesized hybrid (labeled CBNPs@BSA-CUR). The structure and properties of the synthesized nanoparticles were elucidated using transmission electron microscopy (TEM), atomic force microscopy (AFM), ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS) methods. Results: CBNPs@BSA-CUR showed pH sensitivity and were calculated as controlled CUR release behavior. The drug-free system exhibited good biocompatibility and was nontoxic. However, CBNPs@BSA-CUR showed acceptable antiproliferative ability against MCF-7 breast cancer cells. Conclusion: CBNPs@BSA-CUR could be considered a highly promising nontoxic nanocarrier for the delivery of CUR with good biosafety.

Enhanced nuclear gene delivery via integrating and streamlining intracellular pathway

The essential challenge of gene therapy is to develop safe and efficient vectors that escort genes to target sites. However, due to the cumbersome workflow of gene transfection into cells, successive gene loss occurs. This leads to considerable reductions in nuclear gene uptake, eventually causing low gene expression. Herein, we designed a gene vector named CA₃S₂ (C: N,N'-cystamine-bis-acrylamide [CBA], A: agmatine dihydrochloride [Agm], S: 4-(2-aminoethyl) benzenesulfonamide [ABS]) with excellent gene transfection ability. This vector can promote gene delivery to the nucleus via enhanced endoplasmic reticulum (ER) targeting through integrating and streamlining of the complex intracellular pathway. Briefly, ABS endowed CA₃S₂/DNA nanoparticles with not only a natural ER-targeting tendency attributed to the caveolae-mediated pathway but also direct receptor-binding capacity on the ER surface. Agm enabled CA₃S₂ to enhance lysosomal escape and nuclear uptake ability. The gene delivery efficiency of CA₃S₂ was significantly better than that of polyethyleneimine 25K (PEI 25K). Therefore, CA₃S₂ is a promising gene carrier, and the ER-targeting strategy involving intracellular pathway integration and streamlining has potential for gene therapy.

The development of human serum albumin-based drugs and relevant fusion proteins for cancer therapy

Human serum albumin (HSA)-based therapeutics have attracted tremendous attention in the development of anticancer agents. The versatile properties of HSA make HSA-based therapeutics possess improved pharmacokinetics, extended circulation half-life, enhanced efficacy, reduced toxicity, etc. Generally, the HSA-based therapeutics systems can be divided into four categories, i.e. HSA-drug nanoparticles, HSA-drug conjugates, HSA-binding prodrugs, and HSA-based recombinant fusion proteins: the latter mainly include antibody (domain)- and cytokine- fusion proteins. Advances in this area revealed the advantages of HSA-based systems in the development of tumor site-oriented therapeutics, partly referring to the enhanced penetration and retention (EPR) effect and the intensive macropinocytosis. Accordingly, a variety of technical platforms for the design and preparation of HSA-based therapeutics have been reported. Major strategies and directions for the drug development were discussed; those include (1) Tumor-site oriented drug delivery and enhanced drug retention, (2) Tumor-site prodrug release and activation, (3) Cancer cell bound intensive drug internalization, and (4) Tumor microenvironment (TME) directed immunomodulation. Notably, the multimodal HSA-based approach is promising for the development of tumor-oriented therapeutics for cancer therapy.

Recent advances in polymer shell oily-core nanocapsules for drug-delivery applications

Polymeric nanocapsules are vesicular drug-delivery systems composed of an inner oily reservoir surrounded by polymeric membranes. Nanocapsules have various advantages over other nanovesicular systems such as providing controlled drug release properties. We discuss the recent advances in polymeric shell oily-core nanocapsules, illustrating the different types of polymers used and their implementation. Nanocapsules can be utilized for many purposes, especially encapsulation of highly lipophilic drugs. They have been shown to have variable applications, especially in cancer therapy, due to the ability of the polymeric shell to direct the loaded drugs to their target sites, as well as their high internalization efficacy. Those productive applications guaranteed their high potential as drug-delivery systems. However, their clinical development is still in an early stage.

Human Serum Albumin as Multifunctional Nanocarrier for Cancer Therapy

Human serum albumin or simply called albumin is a flexible protein employed as a carrier in the fabrication of albumin-based nanocarriers (ANCs) for the administration of cancer therapeutics. Albumin can contribute enhanced tumour specificity, reduced drug induced cytotoxicity and retain concentration of the therapeutically active agent such as drug, peptide, protein, and gene for a prolonged time duration. Nevertheless, apart from cancer management, ANCs are also employed in the diagnosis, imaging, and multimodal cancer therapy. This article figures out salient characteristics, design as well as categories of ANCs in the context of their application in cancer management. In addition, this review article discusses the fabrication methods of ANCs, use of ANCs in gene, cancer, and multimodal therapy along with cancer diagnosis and imaging. Lastly, this review also briefly discusses about (ANCs) formulations, commercial products, and those under clinical testing.

Three-Dimensional Spheroids as In Vitro Preclinical Models for Cancer Research

Most cancer biologists still rely on conventional two-dimensional (2D) monolayer culture techniques to test in vitro anti-tumor drugs prior to in vivo testing. However, the vast majority of promising preclinical drugs have no or weak efficacy in real patients with tumors, thereby delaying the discovery of successful therapeutics. This is because 2D culture lacks cell–cell contacts and natural tumor microenvironment, important in tumor signaling and drug response, thereby resulting in a reduced malignant phenotype compared to the real tumor. In this sense, three-dimensional (3D) cultures of cancer cells that better recapitulate in vivo cell environments emerged as scientifically accurate and low cost cancer models for preclinical screening and testing of new drug candidates before moving to expensive and time-consuming animal models. Here, we provide a comprehensive overview of 3D tumor systems and highlight the strategies for spheroid construction and evaluation tools of targeted therapies, focusing on their applicability in cancer research. Examples of the applicability of 3D culture for the evaluation of the therapeutic efficacy of nanomedicines are discussed.

A Cationic Nanomicellar Complex of the Quaternary Amphiphilic Amine RC16+ with Fenretinide as a New Multitasking System for Antitumor Therapy

OBJECTIVES

This study investigated the antitumor effect of a new nanomicellar complex obtained by combining the antitumor agent fenretinide with a quaternary amphiphilic amine RC16+ also endowed with antitumor activity.

METHODS

The complex (Fen-RC16+) strongly improved the aqueous solubility of fenretinide (from 1,71 ± 0.08 µg/ml, pure fenretinide to 1500 ± 164 µg /ml, Fen-RC16+ complex) and provided a cytotoxic effect on SH-SY5Y neuroblastoma cell lines resulting from the intrinsic activity of both the complex components. Moreover, the mean size of the nanomicellar complex (ranging from 20 ± 1.97 nm to 40 ± 3.05 nm) was suitable for accumulation to the tumor site by the enhanced permeability and retention effect and the positive charge provided by the quaternary RC16+ induced adsorption of the complex on the tumor cell surface improving the intracellular concentration of fenretinide.

RESULTS

All these characteristics made the Fen-RC16+ complex a multitasking system for antitumor therapy.

CONCLUSION

Indeed its in vivo activity, evaluated on SH-SY5Y xenografts, was strong, and the tumor growth did not resume after the treatment withdrawal.

Multifaceted Roles of Caveolin-1 in Lung Cancer: A New Investigation Focused on Tumor Occurrence, Development and Therapy

Lung cancer is one of the most common and malignant cancers with extremely high morbidity and mortality in both males and females. Although traditional lung cancer treatments are fast progressing, there are still limitations. Caveolin-1 (Cav-1), a main component of caveolae, participates in multiple cellular events such as immune responses, endocytosis, membrane trafficking, cellular signaling and cancer progression. It has been found tightly associated with lung cancer cell proliferation, migration, apoptosis resistance and drug resistance. In addition to this, multiple bioactive molecules have been confirmed to target Cav-1 to carry on their anti-tumor functions in lung cancers. Cav-1 can also be a predictor for lung cancer patients’ prognosis. In this review, we have summarized the valuable research on Cav-1 and lung cancer in recent years and discussed the multifaceted roles of Cav-1 on lung cancer occurrence, development and therapy, hoping to provide new insights into lung cancer treatment.

A Novel Nanomicellar Combination of Fenretinide and Lenalidomide Shows Marked Antitumor Activity in a Neuroblastoma Xenograft Model

Purpose

Currently >50% of high-risk neuroblastoma (NB) patients, despite intensive therapy and initial partial or complete response, develop recurrent NB due to the persistence of minimal residual disease (MRD) that is resistant to conventional antitumor drugs. Indeed, their low therapeutic index prevents drug-dose escalation and protracted administration schedules, as would be required for MRD treatment. Thus, more effective and less toxic therapies are urgently needed for the management of MRD. To address this aim, we evaluated a new combination of fenretinide and lenalidomide, both endowed with antitumor activity and low-toxicity profiles. New nanomicelles were prepared as carriers for this combination to maximize bioavailability and accumulation at the tumor site because of the enhanced permeability and retention (EPR) effect.

Experimental design

New nanomicelles containing the fenretinide–lenalidomide combination (FLnMs) were prepared by a one-step method, providing high drug encapsulation and micelle dimensions suitable for tumor accumulation. Their administration to mice bearing human NB xenografts allowed us to evaluate their efficacy in comparison with the nanomicelles containing fenretinide alone (FnMs).

Results

Treatment by FLnMs significantly decreased the tumor growth of NB xenografts. FLnMs were more active than FnMs despite comparable fenretinide concentrations in tumors, and lenalidomide alone did not show cytotoxic activity in vitro against NB cells. The tumor mass at the end of treatment with FLnMs was predominantly necrotic, with a decreased Ki-67 proliferation index.

Conclusion

FLnMs provided superior antitumor efficacy in NB xenografts compared to FnMs. The enhanced efficacy of the combination was likely due to the antiangiogenic effect of lenalidomide added to the cytotoxic effect of fenretinide. This new nanomicellar combination is characterized by a low-toxicity profile and offers a novel therapeutic option for the treatment of high-risk tumors where the persistence of MRD requires repeated administrations of therapeutic agents over long periods of time to avoid recurrent disease.

A novel oral micellar fenretinide formulation with enhanced bioavailability and antitumour activity against multiple tumours from cancer stem cells

Background

An increasing number of anticancer agents has been proposed in recent years with the attempt to overcome treatment-resistant cancer cells and particularly cancer stem cells (CSC), the major culprits for tumour resistance and recurrence. However, a huge obstacle to treatment success is the ineffective delivery of drugs within the tumour environment due to limited solubility, short circulation time or inconsistent stability of compounds that, together with concomitant dose-limiting systemic toxicity, contribute to hamper the achievement of therapeutic drug concentrations. The synthetic retinoid Fenretinide (4-hydroxy (phenyl)retinamide; 4-HPR) formerly emerged as a promising anticancer agent based on pre-clinical and clinical studies. However, a major limitation of fenretinide is traditionally represented by its poor aqueous solubility/bioavailability due to its hydrophobic nature, that undermined the clinical success of previous clinical trials.

Methods

Here, we developed a novel nano-micellar fenretinide formulation called bionanofenretinide (Bio-nFeR), based on drug encapsulation in an ion-pair stabilized lipid matrix, with the aim to raise fenretinide bioavailability and antitumour efficacy.

Results

Bio-nFeR displayed marked antitumour activity against lung, colon and melanoma CSC both in vitro and in tumour xenografts, in absence of mice toxicity. Bio-nFeR is suitable for oral administration, reaching therapeutic concentrations within tumours and an unprecedented therapeutic activity in vivo as single agent.

Conclusion

Altogether, our results indicate Bio-nFeR as a novel anticancer agent with low toxicity and high activity against tumourigenic cells, potentially useful for the treatment of solid tumours of multiple origin.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1383-9) contains supplementary material, which is available to authorized users.

Albumin Nanovectors in Cancer Therapy and Imaging

Albumin nanovectors represent one of the most promising carriers recently generated because of the cost-effectiveness of their fabrication, biocompatibility, safety, and versatility in delivering hydrophilic and hydrophobic therapeutics and diagnostic agents. In this review, we describe and discuss the recent advances in how this technology has been harnessed for drug delivery in cancer, evaluating the commonly used synthesis protocols and considering the key factors that determine the biological transport and the effectiveness of such technology. With this in mind, we highlight how clinical and experimental albumin-based delivery nanoplatforms may be designed for tackling tumor progression or improving the currently established diagnostic procedures.

Anticancer drug discovery using multicellular tumor spheroid models

INTRODUCTION

Despite the increasing financial outlay on cancer research and drug discovery, many advanced cancers remain incurable. One possible strategy for increasing the approval rate of new anticancer drugs for use in clinical practice could be represented by three-dimensional (3D) tumor models on which to perform in vitro drug screening. There is a general consensus among the scientific community that 3D tumor models more closely recapitulate the complexity of tumor tissue architecture and biology than bi-dimensional cell cultures. In a 3D context, cells are connected to each other through tissue junctions and show proliferative and metabolic gradients that resemble the intricate milieu of organs and tumors. Areas covered: The present review focuses on available techniques for generating tumor spheroids and discusses current and future applications in the field of drug discovery. The article is based on literature obtained from PubMed. Expert opinion: Given the relative simplicity of spheroid models with respect to clinical tumors, we must be careful not to overestimate the reliability of their drug-response prediction capacity. The next challenge is to combine our knowledge of co-culture methodologies with high-content imaging and advanced microfluidic technologies to improve the readout and biomimetic potential of spheroid-based models.

Impact of albumin based approaches in nanomedicine: Imaging, targeting and drug delivery

A major challenge in the field of nanomedicine is to transform laboratory innovations into commercially successful clinical products. In this campaign, a variety of nanoenabled approaches have been designed and investigated for their role in biomedical applications. The advantages associated with the unique structure of albumin imparts it with the ability to interact with variety of molecules, while the functional groups present on their surface provide base for large number of modifications making it as an ideal nanocarrier system. So far, a variety of albumin based nanoenabled approaches have been intensively exploited for effective diagnosis and personalized medicine, among them some have successfully completed their journey from lab bench to marketed products. This review focuses on the recent most promising advancement in the field of albumin based nanoenabled approaches for various biomedical applications and their potential use in cancer diagnosis and therapy.

Results of a phase I-II study of fenretinide and rituximab for patients with indolent B-cell lymphoma and mantle cell lymphoma

Fenretinide, a synthetic retinoid, induces apoptotic cell death in B-cell non-Hodgkin lymphoma (B-NHL) and acts synergistically with rituximab in preclinical models. We report results from a phase I-II study of fenretinide with rituximab for B-NHLs. Eligible diagnoses included indolent B-NHL or mantle cell lymphoma. The phase I design de-escalated from fenretinide at 900 mg/m² PO BID for days 1-5 of a 7-day cycle. The phase II portion added 375 mg/m² IV rituximab weekly on weeks 5-9 then every 3 months. Fenretinide was continued until progression or intolerance. Thirty-two patients were treated: 7 in phase I, and 25 in phase II of the trial. No dose-limiting toxicities were observed. The phase II component utilized fenretinide 900 mg/m² twice daily with rituximab. The most common treatment-related adverse events of grade 3 or higher were rash (n = 3) and neutropenia (n = 3). Responses were seen in 6 (24%) patients on the phase II study, with a median duration of response of 47 months (95% confidence interval, 2-56). The combination of fenretinide and rituximab was well tolerated, yielded a modest overall response rate, but with prolonged remission durations. Further study should focus on identifying the responsive subset of B-NHL.

3D tumor spheroid models for in vitro therapeutic screening: a systematic approach to enhance the biological relevance of data obtained

The potential of a spheroid tumor model composed of cells in different proliferative and metabolic states for the development of new anticancer strategies has been amply demonstrated. However, there is little or no information in the literature on the problems of reproducibility of data originating from experiments using 3D models. Our analyses, carried out using a novel open source software capable of performing an automatic image analysis of 3D tumor colonies, showed that a number of morphology parameters affect the response of large spheroids to treatment. In particular, we found that both spheroid volume and shape may be a source of variability. We also compared some commercially available viability assays specifically designed for 3D models. In conclusion, our data indicate the need for a pre-selection of tumor spheroids of homogeneous volume and shape to reduce data variability to a minimum before use in a cytotoxicity test. In addition, we identified and validated a cytotoxicity test capable of providing meaningful data on the damage induced in large tumor spheroids of up to diameter in 650 μm by different kinds of treatments.