Biocompatibility investigations of synthetic melanin and melanin analogue for application in bioelectronics

Abstract

Biocompatibility tests were performed for melanin synthesized in water (W‐Mel) and dimethylsulfoxide (D‐Mel) aiming to evaluate its potential for bioelectronics application. In vitro biocompatibility of melanin was assessed using crystal violet assays with fibroblast cells (NIH3T3) cultured with W‐Mel and D‐Mel extracts in various dilutions. The results show that a high concentration of melanin kills the cells. However, after periods of 48 h incubation, cell viability is significantly favored after treatment with D‐Mel at low concentrations (1:16, 1:32 and 1:64), as opposed to treatment with W‐Mel extracts. Cellular adhesion tests show that fibroblast cells adhere to melanin thin films. These results show that D‐Mel may be an interesting material for application in bioelectronic devices targeted for implants. © 2016 Society of Chemical Industry

Structural and optical properties of soluble melanin analogues with enhanced photoluminescence quantum efficiency

“…Notice that DMel‐4P has the lowest grain size, which can be related to the higher DHICA/DHI ratio since it is known that DHICA monomers form smaller and more elongated aggregates . Previous AFM results reported a similar effect in DMel . The higher values of d and D for DMel‐8P on the other hand can be assigned to SO 4 2− trapped inside the macromolecule.…”

“…8,21 Previous AFM results reported a similar effect in DMel. 10,11 The higher values of d and D for DMel-8P on the other hand can be assigned to SO 4 2− trapped inside the macromolecule. The same reasoning can be applied to the differences in absorption spectra observed in Fig.…”

“…1). 6 In DMSO, the synthesis is more controlled producing a homogeneous derivative with higher thermal stability, 3 biocompatibility, 10 proton transport properties 11 and solubility in DMSO which enables the production of homogeneous thin films with good substrate adhesion. 3,9,11,12 In the study presented here, we extended our previous work synthesizing melanin in DMSO under O 2 pressure and evaluated the photoluminescence of the derivatives.…”

High-field/high-frequency EPR spectroscopy on synthetic melanin: on the origin of carbon-centered radicals

“…Sulfonated melanin, whose basic structure is shown in Figure 1(b), behaves closely to standard melanin at X-band CW EPR 38 and has promising properties for bioelectronics applications. 17,[54][55][56][57] The experimental results were interpreted with spectral simulations and density functional theory, throwing light on the g-anisotropy of melanin-based radicals and their possible origin.…”

Advances in applying C–H functionalization and naturally sourced building blocks in organic semiconductor synthesis

“…158 The viability of melanin as implanted bioelectronics has also been examined. 159,160 Moreover, there are reports showing the potential of melanin to be used in batteries. [161][162][163] The applications of melanin as an OSM was also carefully reviewed by Shankar et al 142 Compared to indigo, developments of organic electronics using melanin are still in its early stages.…”