Therapeutic potential of a copper complex loaded in pH-sensitive long circulating liposomes for colon cancer management

Copyright © 2021 Elsevier B.V. All rights reserved..

Colorectal carcinoma is a complex malignancy and current therapies are hampered by systemic toxicity and tumor resistance to treatment. In the field of cancer therapy, copper (Cu) compounds hold great promise, with some reaching clinical trials. However, the anticancer potential of Cu complexes has not yet been fully disclosed due to speciation in biological systems, leading to inactivation and/or potential side effects. This is the case of the widely studied Cu(II) complexes featuring phenanthroline ligands, with potent antiproliferative effects in vitro, but often failing in vivo. Aiming to overcome these limitations and maximize its anticancer effects in vivo, the Cu(II) complex (Cu(1,10-phenanthroline)Cl2) (Cuphen), displaying IC50 values <6 μM against different tumor cell lines, was loaded in long circulating liposomes with pH-sensitive properties (F1, DMPC:CHEMS:DSPE-PEG; F2, DOPE:CHEMS:DMPC:DSPE-PEG). This enabled a pH-dependent Cuphen release, with F1 and F2 releasing 36/78% and 47/94% of Cuphen at pH 6/4.5, respectively. The so formed nanoformulations preserved Cuphen effects towards cancer cell lines, with F2 presenting IC50 of 2.7 μM and 4.9 μM towards colon cancer CT-26 and HCT-116 cells, respectively. Additional in vitro studies confirmed that Cuphen antiproliferative activity towards colon cancer cells does not rely on cell cycle effect. Furthermore, in these cells, Cuphen reduced glycerol permeation and impaired cell migration. At 24 h incubation, wound closure was reduced by Cuphen, with migration values of 29% vs 54% (control) and 45% (1,10-phenanthroline) in CT-26 cells, and 33% vs ~44% (control and 1,10-phenanthroline) in HCT-116 cells. These effects were probably due to inhibition of aquaglyceroporins, membrane water and glycerol channels that are often abnormally expressed in tumors. In a syngeneic murine colon cancer model, F2 significantly reduced tumor progression, compared to the control group and to mice treated with free Cuphen or with the ligand, 1,10-phenanthroline, without eliciting toxic side effects. F2 led to a tumor volume reduction of ca. 50%. This was confirmed by RTV analysis, where F2 reached a value of 1.3 vs 4.4 (Control), 5.8 (Phen) and 3.8 (free Cuphen). These results clearly demonstrated the important role of the Cu(II) for the observed biological activity that was maximized following the association to a lipid-based nanosystem. Overall, this study represents a step forward in the development of pH-sensitive nanotherapeutic strategies of metallodrugs for colon cancer management.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:599

Enthalten in:

International journal of pharmaceutics - 599(2021) vom: 15. Apr., Seite 120463

Sprache:

Englisch

Beteiligte Personen:

Pinho, Jacinta O [VerfasserIn]
da Silva, Inês V [VerfasserIn]
Amaral, Joana D [VerfasserIn]
Rodrigues, Cecília M P [VerfasserIn]
Casini, Angela [VerfasserIn]
Soveral, Graça [VerfasserIn]
Gaspar, M Manuela [VerfasserIn]

Links:

Volltext

Themen:

789U1901C5
Antineoplastic Agents
Aquaporins
Copper
Copper complexes
In vitro studies
Journal Article
Liposomes
Metallodrugs
Murine colon cancer model
PH-sensitive liposomes

Anmerkungen:

Date Completed 17.06.2021

Date Revised 17.06.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.ijpharm.2021.120463

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM322683262