Bio-Applications of Multifunctional Melanin Nanoparticles: From Nanomedicine to Nanocosmetics

Abstract

Bioinspired nanomaterials are ideal components for nanomedicine, by virtue of their expected biocompatibility or even complete lack of toxicity. Natural and artificial melanin-based nanoparticles (MNP), including polydopamine nanoparticles (PDA NP), excel for their extraordinary combination of additional optical, electronic, chemical, photophysical, and photochemical properties. Thanks to these features, melanin plays an important multifunctional role in the design of new platforms for nanomedicine where this material works not only as a mechanical support or scaffold, but as an active component for imaging, even multimodal, and simple or synergistic therapy. The number of examples of bio-applications of MNP increased dramatically in the last decade. Here, we review the most recent ones, focusing on the multiplicity of functions that melanin performs in theranostics platforms with increasing complexity. For the sake of clarity, we start analyzing briefly the main properties of melanin and its derivative as well as main natural sources and synthetic methods, moving to imaging application from mono-modal (fluorescence, photoacoustic, and magnetic resonance) to multi-modal, and then to mono-therapy (drug delivery, anti-oxidant, photothermal, and photodynamic), and finally to theranostics and synergistic therapies, including gene- and immuno- in combination to photothermal and photodynamic. Nanomedicine aims not only at the treatment of diseases, but also to their prevention, and melanin in nature performs a protective action, in the form of nanopigment, against UV-Vis radiations and oxidants. With these functions being at the border between nanomedicine and cosmetics nanotechnology, recently examples of applications of artificial MNP in cosmetics are increasing, paving the road to the birth of the new science of nanocosmetics. In the last part of this review, we summarize and discuss these important recent results that establish evidence of the interconnection between nanomedicine and cosmetics nanotechnology.

Synergistic Effect Induced by Gold Nanoparticles with Polyphenols Shell during Thermal Therapy: Macrophage Inflammatory Response and Cancer Cell Death Assessment

“…On the other hand, the HSP-70 induction was strongly reduced to 2.3 ng/mL and 3 ng/mL by the heat and NP treatment in SH-SY5Y and MCF-7 ( Figure 8 m,n). These results are in agreement with previous works, where NPs-polyphenols were used in cancer cells [ 93 , 94 ] and triggered the release of the HSP family, followed by the activation of anti-tumoral pathways [ 95 ]. In our work, the synergic effect of Au, polyphenols, and heat enhanced the inactivation of HSP-70, a critical aspect in cancer therapy applications.…”

Applications of Melanin and Melanin-Like Nanoparticles in Cancer Therapy: A Review of Recent Advances

“…The large physicochemical variety of properties of melanin along with its inherent biocompatibility have inspired scientists to design novel melanin-like nanoparticles for diverse fields ranging from nanomedicine to nanocosmetics [ 45 ]. Melanin applications in photothermal therapy (PTT) and delivery drug systems have sparked attention in the field of cancer therapy.…”

“…Melanin is an excellent candidate for drug delivery system given its biocompatibility, biodegradability, high loading efficiency, and the possibility of manipulating both binding and release of drugs [ 45 ]. Due to such unique features, melanin is under development as a carrier for antigenic peptides in vaccines.…”

“…Due to such unique features, melanin is under development as a carrier for antigenic peptides in vaccines. Peptides are widely used as an antigen source because of their low toxicity, low cost, and the presence of direct functional T-cell epitopes [ 45 ]. However, free peptides rapidly reach the systemic circulation after subcutaneous injection and only a small portion of the injected dose is captured by antigen-presenting cells (APCs).…”

The Nanosystems Involved in Treating Lung Cancer

“…Another interesting approach suggests the combination of inorganic materials using the PDT technique. Porphyrin-silica nanoparticles may be such an example, which proved to be useful due to both intense their fluorescence (that may be suitable for cell labelling) and sufficient reactive oxygen species (ROS) generation to inhibit tumor growth [ 196 ].…”