Selective targeting of melanoma by PEG-masked protein-based multifunctional nanoparticles

Abstract

Background: Nanoparticle-based systems are promising for the development of imaging and therapeutic agents. The main advantage of nanoparticles over traditional systems lies in the possibility of loading multiple functionalities onto a single molecule, which are useful for therapeutic and/or diagnostic purposes. These functionalities include targeting moieties which are able to recognize receptors overexpressed by specific cells and tissues. However, targeted delivery of nanoparticles requires an accurate system design. We present here a rationally designed, genetically engineered, and chemically modified protein-based nanoplatform for cell/tissue-specific targeting. Methods: Our nanoparticle constructs were based on the heavy chain of the human protein ferritin (HFt), a highly symmetrical assembly of 24 subunits enclosing a hollow cavity. HFt-based nanoparticles were produced using both genetic engineering and chemical functionalization methods to impart several functionalities, ie, the α-melanocyte-stimulating hormone peptide as a melanoma-targeting moiety, stabilizing and HFt-masking polyethylene glycol molecules, rhodamine fluorophores, and magnetic resonance imaging agents. The constructs produced were extensively characterized by a number of physicochemical techniques, and assayed for selective melanoma-targeting in vitro and in vivo. Results: Our HFt-based nanoparticle constructs functionalized with the α-melanocytestimulating hormone peptide moiety and polyethylene glycol molecules were specifically taken up by melanoma cells but not by other cancer cell types in vitro. Moreover, experiments in melanoma-bearing mice indicate that these constructs have an excellent tumor-targeting profile and a long circulation time in vivo. Conclusion: By masking human HFt with polyethylene glycol and targeting it with an α-melanocyte-stimulating hormone peptide, we developed an HFt-based melanoma-targeting nanoplatform for application in melanoma diagnosis and treatment. These results could be of general interest, because the same strategy can be exploited to develop ad hoc nanoplatforms for specific delivery towards any cell/tissue type for which a suitable targeting moiety is available. Keywords: multifunctional nanoparticles, ferritin, nanoplatform, cancer-targeting, melanoma IntroductionDevelopment of multifunctional nanoparticles for nanomedicine applications, such as cell/tissue-specific delivery, biomedical imaging and therapy, has recently gained wide popularity. [1][2][3][4] Various types of materials, including synthetic polymers and lipids, have been increasingly utilized as platforms for nanoparticle synthesis. 1,5 Despite the large number of bioconjugation techniques available, the attainment of multifunctional nanoprobes endowed with desired bioactivity, targeting specificity, and stability remains a challenge. Approaches using protein-cage structures, such as proteins belonging to the ferritin family, are novel and very promising. 6,7 Apoferritin is a highly symmetrical multimeric protein consisting of 2...

Targeting of BRAF resistant melanoma via extracellular matrix metalloproteinase inducer receptor

“…Two different groups have attempted cell-specific targeting of melanoma cells in vivo, demonstrating methods that could potentially reduce systemic toxicity in chemotherapeutic drug delivery. Alpha-melanocyte stimulating hormone has been conjugated to human ferritin nanoparticles; this approach demonstrated in vivo melanoma tumor-accumulation at 24 hours (31). Another group used EP1, a monoclonal antibody to the human melanoma-specific antigen CSPG4, conjugated to a single ferritin cage and encapsulating cisplatin (32).…”

Ferritin-based nanomedicine for disease treatment

“…Vannucci et al. [ 86 ] incubated ferritin with methoxypolyethylene glycol maleimide to prepare PEGylated ferritin nanocage, which showed more persistent circulation. Kang et al.…”

“…[ 89 ] fused RGD4C peptide, ligand of α v β 3 integrins upregulated on tumor vasculature, to the N-terminal of human H-ferritin subunit, incorporating it on the exterior surface of ferritin, which resulted in enhanced melanoma targeting ability. α-melanocyte-stimulating hormone peptide was also fused to the N-terminal of ferritin subunit and displayed at the outer surface, which significantly enhanced ferritin’s ability to target melanoma [ 86 ]. Lee et al.…”

Functionalizing Ferritin Nanoparticles for Vaccine Development

“…By adding targeting moieties to the external surface of ferritin, the encapsulated molecules can be delivered in a site-specific manner. Additionally, the outer surface of ferritin can be engineered to impart increased circulatory half-life (e.g., PEG [ 69 ], PAS polypeptides [ 70 ]) and, most importantly, to trigger specific cellular responses (e.g., antigens, antibodies, nucleotides) [ 14 ]. In the following sections, functionalization of the outer surface of ferritin will be thoroughly described since this interface enables antigen presentation for the development of ferritin-based vaccines ( Figure 3 ).…”