Antiproliferative Activity and VEGF Expression Reduction in MCF7 and PC-3 Cancer Cells by Paclitaxel and Imatinib Co-encapsulation in Folate-Targeted Liposomes

Folic Acid-Modified Long-Circulating Liposomes Loaded with Sulfasalazine For Targeted Induction of Ferroptosis in Melanoma

Melanoma is a malignant tumor that originates from melanocytes. The incidence of melanoma is increasing worldwide, partially because of its insensitivity to radiotherapy or chemotherapy. Therefore, effective treatments for melanoma are urgently required. In this study, we employed folic acid-modified sulfasalazine long-circulating liposomes (FA-SSZ-Lips) to precisely target drug delivery to melanoma cells, eliciting ferroptosis effectively. The synthesized FA-SSZ-Lips were characterized as small spheres of a double-layer membrane, a particle size of 110.1 nm, and a ζ-potential of -22.8 ± 0.66 mV. FA-SSZ-Lips are effective drug carriers with SSZ-loading ratio and SSZ release rate of 6.2 ± 0.10%, and 72.63 ± 1.40%, respectively. The liposomes enhanced SSZ solubility, and the folic acid modifications increased the liposome targeting to melanoma cells. Compared with SSZ alone, FA-SSZ-Lips more strongly inhibited B16F10 cell growth, significantly disrupted the intracellular redox balance, and induced ferroptosis. After treatment, considerable differences were observed in the tumor volumes between FA-SSZ-Lips and phosphate-buffered saline control groups. The tumor growth-inhibition value of the FA-SSZ-Lips group reached 70.09%. Thus, FA-SSZ-Lips exhibited favorable antitumor effects in vitro and in vivo and are a promising strategy for melanoma treatment.

Insights into Lipid-Based Delivery Nanosystems of Protein-Tyrosine Kinase Inhibitors for Cancer Therapy

According to the WHO, cancer caused almost 10 million deaths worldwide in 2020, i.e., almost one in six deaths. Among the most common are breast, lung, colon and rectal and prostate cancers. Although the diagnosis is more perfect and spectrum of available drugs is large, there is a clear trend of an increase in cancer that ends fatally. A major advance in treatment was the introduction of gentler antineoplastics for targeted therapy-tyrosine kinase inhibitors (TKIs). Although they have undoubtedly revolutionized oncology and hematology, they have significant side effects and limited efficacy. In addition to the design of new TKIs with improved pharmacokinetic and safety profiles, and being more resistant to the development of drug resistance, high expectations are placed on the reformulation of TKIs into various drug delivery lipid-based nanosystems. This review provides an insight into the history of chemotherapy, a brief overview of the development of TKIs for the treatment of cancer and their mechanism of action and summarizes the results of the applications of self-nanoemulsifying drug delivery systems, nanoemulsions, liposomes, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles and nanostructured lipid carriers used as drug delivery systems of TKIs obtained in vitro and in vivo.

Folate-Targeted PEGylated Magnetoliposomes for Hyperthermia-Mediated Controlled Release of Doxorubicin

Doxorubicin (DOX) is a chemotherapeutic agent commonly used for the treatment of solid tumors. However, the cardiotoxicity associated with its prolonged use prevents further adherence and therapeutic efficacy. By encapsulating DOX within a PEGylated liposome, Doxil^® considerably decreased DOX cardiotoxicity. By using thermally sensitive lysolipids in its bilayer composition, ThermoDox^® implemented a heat-induced controlled release of DOX. However, both ThermoDox^® and Doxil^® rely on their passive retention in tumors, depending on their half-lives in blood. Moreover, ThermoDox^® ordinarily depend on invasive radiofrequency-generating metallic probes for local heating. In this study, we prepare, characterize, and evaluate the antitumoral capabilities of DOX-loaded folate-targeted PEGylated magnetoliposomes (DFPML). Unlike ThermoDox^®, DOX delivery via DFPML is mediated by the heat released through dynamic hysteresis losses from magnetothermal converting systems composed by MnFe₂O₄ nanoparticles (NPs) under AC magnetic field excitation—a non-invasive technique designated magnetic hyperthermia (MHT). Moreover, DFPML dismisses the use of thermally sensitive lysolipids, allowing the use of simpler and cheaper alternative lipids. MnFe₂O₄ NPs and DFPML are fully characterized in terms of their size, morphology, polydispersion, magnetic, and magnetothermal properties. About 50% of the DOX load is released from DFPML after 30 min under MHT conditions. Being folate-targeted, in vitro DFPML antitumoral activity is higher (IC₅₀ ≈ 1 μg/ml) for folate receptor-overexpressing B16F10 murine melanoma cells, compared to MCF7 human breast adenocarcinoma cells (IC₅₀ ≈ 4 μg/ml). Taken together, our results indicate that DFPML are strong candidates for folate-targeted anticancer therapies based on DOX controlled release.

Nanotechnology of Tyrosine Kinase Inhibitors in Cancer Therapy: A Perspective

Nanotechnology is an important application in modern cancer therapy. In comparison with conventional drug formulations, nanoparticles ensure better penetration into the tumor mass by exploiting the enhanced permeability and retention effect, longer blood circulation times by a reduced renal excretion and a decrease in side effects and drug accumulation in healthy tissues. The most significant classes of nanoparticles (i.e., liposomes, inorganic and organic nanoparticles) are here discussed with a particular focus on their use as delivery systems for small molecule tyrosine kinase inhibitors (TKIs). A number of these new compounds (e.g., Imatinib, Dasatinib, Ponatinib) have been approved as first-line therapy in different cancer types but their clinical use is limited by poor solubility and oral bioavailability. Consequently, new nanoparticle systems are necessary to ameliorate formulations and reduce toxicity. In this review, some of the most important TKIs are reported, focusing on ongoing clinical studies, and the recent drug delivery systems for these molecules are investigated.

Progresses in polymeric nanoparticles for delivery of tyrosine kinase inhibitors

Tyrosine kinase inhibitors (TKIs), as an important class of chemotherapeutic drugs, induce apoptosis by altering the path of the cellular signal, resulting in cell death. However, some chemotherapeutic drugs have a limited therapeutic index and are usually destructive as well as unpredictable. In addition, the limitation of early diagnosis and inefficiency of some of the drugs in ordinary treatments lead to disease progression and decreases in the survival of cancer patients. For this purpose, various methods have been proposed, among them, nanomedicine has transpired as a modern approach for the treatment of multiple cancers. Over the last two decades, targeted therapy has been developed for cancer-specific cells/tissues and has rather restricted nonselective toxicities. In vivo and in vitro studies demonstrated nanoparticles (NPs), nano-scale drugs, and nano-carriers alone or in combination with other therapeutic, imaging, and theranostic agents would be applied as an effective approach targeting a diversity of malignant tissue. Therefore, using the latest advances in materials science and biomaterials, biology, it has happened that general diagnosis and treatment can be performed. In this review, we indicated the applications of theranostic nano-polymer and nano-liposome to TKIs delivery.

A promising dual-drug targeted delivery system in cancer therapy: nanocomplexes of folate-apoferritin-conjugated cationic solid lipid nanoparticles

Various nano-sized protein and lipid complexes are being investigated as drug delivery systems. The encapsulation of more than one drug in a single nanocomplex carrier could enhance the therapeutic potency and afford synergistic therapeutic effects. In this study, we developed a novel protein-lipid nanocomplex as a controlled drug delivery system for two important cancer drugs, doxorubicin (DOX) and mitoxantrone (MTO). Apoferritin (AFr) functionalized with folic acid (FA) was used to encapsulate DOX to create the targeted protein nanocomplexes (TPNs). The second drug, MTO, was loaded into the cationic solid lipid nanoparticles (cSLN) to form the liposomal drug nanocomplex particles (MTO-cSLNs). Two complexes were then assembled by tight coupling through ionic interactions to obtain the final drug delivery system, the dual-targeted protein-lipid nanocomplexes (DTPLNs). UV-Vis and fluorescence spectroscopy were used for structural characterization of TPNs and DTPLNs. Transmission electron microscopy (TEM) was used for comprehensive analysis of the final DTPLNs. We confirmed that the DTPLNs display desired time-dependent and pH-dependent drug release behaviors. We also demonstrated the improved anti-cancer efficacy of DOX and MTO in their encapsulated DTPLNs as compared to their free forms. Our results provide promising prospects for the application of the DTPLNs as efficient drug delivery systems.

Development and validation of a rapid RP-HPLC method for simultaneous quantification of paclitaxel and cetuximab in immunoliposomes

The development of rational therapies against complex diseases, such as cancer, has increased in the past few years due to the advances of 'omics' technologies. Concomitantly, several efforts have been made to design sophisticated drug delivery systems in order to increase specificity and drug accumulation in tumor sites. The complexity of these drug delivery systems highlights the need for suitable analytical methods to determine encapsulation/conjugation efficiency of drugs and molecules responsible for the targeted delivery. Therefore, this study focuses on the development and validation of a RP-HPLC-DAD methodology for concurrent quantification of paclitaxel (PTX) and cetuximab (CTX) in immunoliposomes. Chromatographic separation was achieved using a wide pore C₈ column, and a gradient mobile phase consisting of 0.1% trifluoroacetic acid (TFA) in Milli-Q water/acetonitrile/isopropanol with a flow rate of 1 mL min^-1. Drug peaks were fully separated and detected at 280 nm using UV detector. The method was validated according to ICH and FDA guidelines in terms of specificity and forced degradation studies, system suitability, linearity, limit of detection, limit of quantification, repeatability, intermediate precision, accuracy, robustness, and short-term stability. The developed method was linear over the concentration range of 37.5-150 μg mL^-1 of PTX and 75-300 μg mL^-1 of CTX. All parameters evaluated satisfied the acceptance criteria, according to both FDA and ICH guidelines. The applicability of the analytical method was assessed following the development of PTX-loaded immunoliposomes conjugated with CTX. Thus, the present study shows a novel, simple, stability-indicating and suitable method to quantify simultaneously PTX and CTX in immunoliposomes.

Single- versus Dual-Targeted Nanoparticles with Folic Acid and Biotin for Anticancer Drug Delivery

Cancer is one of the major causes of death worldwide and its treatment remains very challenging. The effectiveness of cancer therapy significantly depends upon tumour-specific delivery of the drug. Nanoparticle drug delivery systems have been developed to avoid the side effects of the conventional chemotherapy. However, according to the most recent recommendations, future nanomedicine should be focused mainly on active targeting of nanocarriers based on ligand-receptor recognition, which may show better efficacy than passive targeting in human cancer therapy. Nevertheless, the efficacy of single-ligand nanomedicines is still limited due to the complexity of the tumour microenvironment. Thus, the NPs are improved toward an additional functionality, e.g., pH-sensitivity (advanced single-targeted NPs). Moreover, dual-targeted nanoparticles which contain two different types of targeting agents on the same drug delivery system are developed. The advanced single-targeted NPs and dual-targeted nanocarriers present superior properties related to cell selectivity, cellular uptake and cytotoxicity toward cancer cells than conventional drug, non-targeted systems and single-targeted systems without additional functionality. Folic acid and biotin are used as targeting ligands for cancer chemotherapy, since they are available, inexpensive, nontoxic, nonimmunogenic and easy to modify. These ligands are used in both, single- and dual-targeted systems although the latter are still a novel approach. This review presents the recent achievements in the development of single- or dual-targeted nanoparticles for anticancer drug delivery.

Novel Strategies for Targeting Prostate Cancer

Prostate cancer (PCa) is a worldwide issue, with a rapid increase in its occurrence and mortality. Over the years, various strategies have been implemented to overcome the hurdles that exist in the treatment of PCa. Consistently, there is a change in opinion about the methodologies in clinical trial that have engrossed towards the treatment of PCa. Currently, there is a need to resolve these newly recognized challenges by developing newer rational targeting systems. The ongoing clinical protocol for the therapy using different targeting systems is undertaken followed by local targeting to cancer site. A number of new drug targeting systems like liposomes, nanoemulsions, magnetic nanoparticles (MNPs), solid lipid nanoparticles, drug-peptide conjugate systems, drug-antibody conjugate systems, epigenetic and gene therapy approaches, and therapeutic aptamers are being developed to suit this protocol. Recent advancements in the treatment of PCa with various nanocarriers have been reported with respect to newly identified biological barriers and intended to solve the contexts. This review encompasses the input of nanotechnology in particular targeting of PCa which might escape the lifethreatening side effects and potentially contribute to bring fruitful clinical outcomes.

Poly(L-Glutamic Acid)-Based Brush Copolymers: Fabrication, Self-assembly, and Evaluation as Efficient Nanocarriers for Cationic Protein Drug Delivery

Protein drugs were considered to be the first choice to treat many human diseases, but their clinical application was usually limited by their short half-life and lack of validated targeted therapy. Here, a series of folate-functionalized poly(ethylene glycol)-b-(poly(2-aminoethyl-L-glutamate)-g-poly(L-glutamic acid))s (FA-PEG-b-(PELG-g-PLGA)s) were designed as tumor-targeted carriers for cationic protein delivery. Compared with traditional copolymers consisting of PEG and linear charged hydrophilic blocks, FA-PEG-b-(PELG-g-PLGA) with brush-like polyelectrolyte segments were beneficial to improving their electrostatic interactions with loading protein molecules, thus increasing drug-loading stability and protecting encapsulated proteins from degradation. The designed polymer brushes could efficiently encapsulate cytochrome C (CytC), a cationic model protein, to form polyion complex (PIC) micelles with an average particle size of approximately 200 nm. An in vitro drug release study showed that the drug-loading stability of the formed PIC micelles was largely improved. The functionalization of the block copolymer carriers with a targeting folate group enhanced the tumor cell growth inhibition and total apoptotic rates induced by CytC. Our results shed light on the unique advantages of brush-like polymer carriers in delivering cationic proteins, and the poly(L-glutamic acid)-based linear-brush diblock copolymers could be applied as a versatile delivery platform for molecular targeting in cancer therapy.

Surface engineering of nanomaterials with phospholipid-polyethylene glycol-derived functional conjugates for molecular imaging and targeted therapy

In recent years, phospholipid-polyethylene glycol-derived functional conjugates have been widely employed to decorate different nanomaterials, due to their excellent biocompatibility, long blood circulation characteristics, and specific targeting capability. Numerous in vivo studies have demonstrated that nanomedicines peripherally engineered with phospholipid-polyethylene glycol-derived functional conjugates show significantly increased selective and efficient internalization by target cells/tissues. Targeting moieties including small-molecule ligands, peptides, proteins, and antibodies are generally conjugated onto PEGylated phospholipids to decorate liposomes, micelles, hybrid nanoparticles, nanocomplexes, and nanoemulsions for targeted delivery of diagnostic and therapeutic agents to diseased sites. In this review, the synthesis methods of phospholipid-polyethylene glycol-derived functional conjugates, biophysicochemical properties of nanomedicines decorated with these conjugates, factors dominating their targeting efficiency, as well as their applications for in vivo molecular imaging and targeted therapy were summarized and discussed.

Formulation Strategies for Folate-Targeted Liposomes and Their Biomedical Applications

The folate receptor (FR) is a tumor-associated antigen that can bind with folic acid (FA) and its conjugates with high affinity and ingests the bound molecules inside the cell via the endocytic mechanism. A wide variety of payloads can be delivered to FR-overexpressed cells using folate as the ligand, ranging from small drug molecules to large DNA-containing macromolecules. A broad range of folate attached liposomes have been proven to be highly effective as the targeted delivery system. For the rational design of folate-targeted liposomes, an intense conceptual understanding combining chemical and biomedical points of view is necessary because of the interdisciplinary nature of the field. The fabrication of the folate-conjugated liposomes basically involves the attachment of FA with phospholipids, cholesterol or peptides before liposomal formulation. The present review aims to provide detailed information about the design and fabrication of folate-conjugated liposomes using FA attached uncleavable/cleavable phospholipids, cholesterol or peptides. Advances in the area of folate-targeted liposomes and their biomedical applications have also been discussed.