Preclinical validation of a new hybrid molecule loaded in liposomes for melanoma management

Combination of gold nanoparticles with near-infrared light as an alternative approach for melanoma management

Melanoma is the most aggressive type of skin cancer and recently approved drugs are often associated with resistance and significant adverse effects. Therefore, the design of more effective and safe options remains imperative. Photothermal therapy (PTT) using gold nanoparticles (AuNPs) presents a promising and innovative approach. In this work, the efficacy of combining a previously optimized formulation of AuNPs coated with a mixture of hyaluronic and oleic acids (HAOA-AuNPs) with near-infrared (NIR) laser irradiation in melanoma cell lines was explored. Coated and uncoated AuNPs formulations were characterized in physicochemical, morphological and elemental terms. Next, the cellular uptake efficiency as well as antiproliferative activity of the combination of each formulation with laser irradiation was evaluated. Subsequently, HAOA-AuNPs were selected to assess the underlying mechanism of combined therapy by cell cycle and Annexin V/PI assays. An in vivo syngeneic murine melanoma model was also conducted. In vitro studies demonstrated that 24 h after incubation and in the absence of laser, HAOA-AuNPs did not exhibit cytotoxic effects on the melanoma cell lines tested, similar to the laser alone. On the contrary, the combination therapy resulted in a large reduction in cell viability. Furthermore, it has been shown to promote S-phase cell cycle arrest and increase in the percentage of late apoptotic cells. Finally, the in vivo proof-of-concept showed that the intratumoral administration of HAOA-AuNPs followed by three laser irradiations impaired tumor progression. Collectively, AuNP-based PTT holds significant potential to improve treatment efficacy and safety, offering a versatile and potent tool against cancer.

Liposomal Formulation of an Organogold Complex Enhancing Its Activity as Antimelanoma Agent-In Vitro and In Vivo Studies

Background/Objectives: The therapeutic management of melanoma, the most aggressive form of skin cancer, remains challenging. In the search for more effective therapeutic options, metal-based complexes are being investigated for their anticancer properties. Cisplatin was the first clinically approved platinum-based drug and, based on its success, other metals (e.g., gold) are being used to design novel compounds. Methods: the antimelanoma potential of a new organometallic cyclometalated Au(III) complex [[Au(CNOxN)Cl2] (CNOxN = 2-(phenyl-(2-pyridinylmethylene)aminoxy acetic acid))] (ST004) was evaluated in vitro and in vivo. Furthermore, the gold-based complex was incorporated in liposomes to overcome solubility and stability problems, to promote accumulation at melanoma sites and to maximize the therapeutic effect while controlling its reactivity. The antiproliferative activity of ST004 formulations was assessed in murine (B16F10) and human (A375 and MNT-1) melanoma cell lines after 24 and 48 h incubation periods. The proof-of-concept of the antimelanoma properties of ST004 formulations was carried out in subcutaneous and metastatic murine melanoma models. Results: the developed liposomal formulations showed a low mean size (around 100 nm), high homogeneity (with a low polydispersity index) and high incorporation efficiency (51 ± 15%). ST004 formulations exhibited antiproliferative activity with EC50 values in the μmolar range being cell-line- and incubation-period-dependent. On the opposite side, the benchmark antimelanoma compound, dacarbazine (DTIC), presented an EC50 > 100 μM. Cell cycle analysis revealed an arrest in G0/G1 phase for Free-ST004 in all cell lines. In turn, LIP-ST004 led to a G0/G1 halt in B16F10, and to an arrest in S phase in A375 and MNT-1 cells. Preliminary mechanistic studies in human red blood cells suggest that gold-based inhibition of glycerol permeation acts through aquaglyceroporin 3 (AQP3). In a metastatic murine melanoma, a significant reduction in lung metastases in animals receiving LIP-ST004, compared to free gold complex and DTIC, was observed. Conclusion: This study highlights the antimelanoma potential of a new gold-based complex. Additional studies, namely in vivo biodistribution profile and therapeutic validation of this organogold complex in other melanoma models, are expected to be performed in further investigations.

An alternative hybrid lipid nanosystem combining cytotoxic and magnetic properties as a tool to potentiate antitumor effect of 5-fluorouracil

AIMS

Colorectal cancer is the third most frequent type of cancer and the second leading cause of cancer-related deaths worldwide. The majority of cases are diagnosed at a later stage, leading to the need for more aggressive treatments such as chemotherapy. 5-Fluorouracil (5-FU), known for its high cytotoxic properties has emerged as a chemotherapeutic agent. However, it presents several drawbacks such as lack of specificity and short half-life. To reduce these drawbacks, several strategies have been designed namely chemical modification or association to drug delivery systems.

MATERIALS AND METHODS

Current research was focused on the design, physicochemical characterization and in vitro evaluation of a lipid-based system loaded with 5-FU. Furthermore, aiming to maximize preferential targeting and release at tumour sites, a hybrid lipid-based system, combining both therapeutic and magnetic properties was developed and validated. For this purpose, liposomes co-loaded with 5-FU and iron oxide (II, III) nanoparticles were accomplished.

KEY FINDINGS

The characterization of the developed nanoformulation was performed in terms of incorporation parameters, mean size and surface charge. In vitro studies assessed in a murine colon cancer cell line confirmed that 5-FU antiproliferative activity was preserved after incorporation in liposomes. In same model, iron oxide (II, III) nanoparticles did not exhibit cytotoxic properties. Additionally, the presence of these nanoparticles was shown to confer magnetic properties to the liposomes, allowing them to respond to external magnetic fields.

SIGNIFICANCE

Overall, a lipid nanosystem loading a chemotherapeutic agent displaying magnetic characteristics was successfully designed and physicochemically characterized, for further in vivo applications.

Panobinostat-loaded folate targeted liposomes as a promising drug delivery system for treatment of canine B-cell lymphoma

Introduction

Cancer is a major public health problem with over 19 million cases reported in 2020. Similarly to humans, dogs are also largely affected by cancer, with non-Hodgkin's lymphoma (NHL) among the most common cancers in both species. Comparative medicine has the potential to accelerate the development of new therapeutic options in oncology by leveraging commonalities between diseases affecting both humans and animals. Within this context, in the present study, we investigated the potential of panobinostat (Pan)-loaded folate-targeted PEGylated liposomes (FA-PEG-Pan-Lip) for the treatment of canine B-cell lymphoma, while contributing to new perspectives in comparative oncology.

Methods and results

Two formulations were developed, namely: PEG-Pan-Lip and FA-PEG-Pan-Lip. Firstly, folate receptor expression in the CLBL-1 canine B-cell lymphoma cell line was assessed. After confirming receptor expression, both Pan-loaded formulations (PEG-Pan-Lip, FA-PEG-Pan-Lip) demonstrated dose-dependent inhibitory effects on CLBL-1 cell proliferation. The FA-PEG-Pan-Lip formulation (IC50 = 10.9 ± 0.03 nM) showed higher cytotoxicity than the non-targeted PEG-Pan-Lip formulation (IC50 = 12.9 ± 0.03 nM) and the free panobinostat (Pan) compound (IC50 = 18.32±0.03 nM). Moreover, mechanistically, both Pan-containing formulations induced acetylation of H3 histone and apoptosis. Flow cytometry and immunofluorescence analysis of intracellular uptake of rhodamine-labeled liposome formulations in CLBL-1 cells confirmed cellular internalization of PEG-Lip and FA-PEG-Lip formulations and higher uptake profile for the latter. Biodistribution studies of both radiolabeled formulations in CD1 and SCID mice revealed a rapid clearance from the major organs and a 1.6-fold enhancement of tumor uptake at 24 h for 111In-FA-PEG-Pan-Lip (2.2 ± 0.1 %ID/g of tumor) compared to 111In-PEG-Pan-Lip formulation (1.2±0.2 %ID/g of tumor).

Discussion

In summary, our results provide new data validating Pan-loaded folate liposomes as a promising targeted drug delivery system for the treatment of canine B-cell lymphoma and open innovative perspectives for comparative oncology.

A step forward on the in vitro and in vivo assessment of a novel nanomedicine against melanoma

Melanoma is the most aggressive form of skin cancer, with increasing incidence and mortality rates. To overcome current treatment limitations, a hybrid molecule (HM) combining a triazene and a ʟ-tyrosine analogue, was recently synthesized, incorporated in long blood circulating liposomes (LIP HM) and validated in an immunocompetent melanoma model. The present work constitutes a step forward in the therapeutic assessment of HM formulations. Here, human melanoma cells, A375 and MNT-1, were used and dacarbazine (DTIC), a triazene drug clinically available as first-line treatment for melanoma, constituted the positive control. In cell cycle analysis, A375 cells, after 24-h incubation with HM (60 μM) and DTIC (70 μM), resulted in a 1.2 fold increase (related to control) in the percentage of cells in G0/G1 phase. The therapeutic activity was evaluated in a human murine melanoma model (subcutaneously injected with A375 cells) to most closely resemble the human pathology. Animals treated with LIP HM exhibited the highest antimelanoma effect resulting in a 6-, 5- and 4-fold reduction on tumor volume compared to negative control, Free HM and DTIC groups, respectively. No toxic side effects were detected. Overall, these results constitute another step forward in the validation of the antimelanoma activity of LIP HM, using a murine model that more accurately simulates the pathology that occurs in human patients.

Safety of Gold Nanoparticles: From In Vitro to In Vivo Testing Array Checklist

In recent years, gold nanoparticles (AuNPs) have aroused the interest of many researchers due to their unique physicochemical and optical properties. AuNPs are being explored in a variety of biomedical fields, either in diagnostics or therapy, particularly for localized thermal ablation of cancer cells after light irradiation. Besides the promising therapeutic potential of AuNPs, their safety constitutes a highly important issue for any medicine or medical device. For this reason, in the present work, the production and characterization of physicochemical properties and morphology of AuNPs coated with two different materials (hyaluronic and oleic acids (HAOA) and bovine serum albumin (BSA)) were firstly performed. Based on the above importantly referred issue, the in vitro safety of developed AuNPs was evaluated in healthy keratinocytes, human melanoma, breast, pancreatic and glioblastoma cancer cells, as well as in a three-dimensional human skin model. Ex vivo and in vivo biosafety assays using, respectively, human red blood cells and Artemia salina were also carried out. HAOA-AuNPs were selected for in vivo acute toxicity and biodistribution studies in healthy Balb/c mice. Histopathological analysis showed no significant signs of toxicity for the tested formulations. Overall, several techniques were developed in order to characterize the AuNPs and evaluate their safety. All these results support their use for biomedical applications.

Advancing Medicine with Lipid-Based Nanosystems-The Successful Case of Liposomes

Nanomedicine, a promising area of medicine, employs nanosized tools for the diagnosis, prevention, and treatment of disease. Particularly, liposomes, lipid-based nanovesicles, are currently one of the most successful nanosystems, with extensive applications in the clinic and an increasing pipeline of products in preclinical and clinical development. These versatile nanotechnological tools are biocompatible and biodegradable, and can load a variety of molecules and, ultimately, improve the therapeutic performance of drugs while minimizing undesired side effects. In this review, we provide a brief description on liposomes' composition and classification and mainly focus on their clinical use in various areas, including disease management (e.g., cancer, fungal and bacterial infections, ocular pathologies), analgesia, vaccination, diagnostics, and immunosuppression in organ transplantation. Herein are described examples of current liposomal products already in the clinic, as well as the most recent clinical trials involving liposomes as effective and safe nanomedicine tools.