Stable and Biocompatible Monodispersion of C60 in Water by

Jan 7, 2019 - Dipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum − Università di Bologna , Via Francesco Selmi, 2 − 40126 Bolo...
0 downloads 0 Views 432KB Size
Subscriber access provided by EKU Libraries

Article

A Stable and Biocompatible Monodispersion of C60 in Water by Peptides. Matteo Di Giosia, Federica Nicolini, Lucia Ferrazzano, Alice Soldà, Francesco Valle, Andrea Cantelli, Tainah Dorina Marforio, Andrea Bottoni, Francesco Zerbetto, Marco Montalti, Stefania Rapino, Alessandra Tolomelli, and Matteo Calvaresi Bioconjugate Chem., Just Accepted Manuscript • DOI: 10.1021/acs.bioconjchem.8b00916 • Publication Date (Web): 07 Jan 2019 Downloaded from http://pubs.acs.org on January 12, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Bioconjugate Chemistry

A Stable and Biocompatible Monodispersion of C60 in Water by Peptides. Matteo Di Giosia,† Federica Nicolini,† Lucia Ferrazzano,† Alice Soldà, † Francesco Valle,‡ Andrea Cantelli,† Tainah Dorina Marforio,† Andrea Bottoni,† Francesco Zerbetto,† Marco Montalti,† Stefania Rapino, † Alessandra Tolomelli,*,† Matteo Calvaresi*,† Dipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum – Università di Bologna, Via Francesco Selmi, 2 – 40126 Bologna, Italy †



Istituto per lo Studio dei Materiali Nanostrutturati, ISMN-CNR, via Gobetti 101, 40129 Bologna, Italy

ABSTRACT: The lack of solubility in water and the formation of aggregates hamper many opportunities of technological exploitation of C60. Here different peptides were designed and synthesized with the aim of dispersing monomolecularly C60 in water. Phenylalanines were used as recognizing moieties, able to interact with C60 through π−π stacking, while a varying number of glycines were used as spacers, to connect the two terminal phenylalanines. The best performance in the dispersion of C60 was obtained with the FGGGF peptidic nanotweezer at a pH of 12. A full characterization of this adduct was carried out. The peptides disperse C60 in water with high efficiency, and the solutions are stable for months both in pure water and in physiological environments. NMR measurements demonstrated the ability of the peptides to interact with C60. AFM measurements showed that C60 is monodispersed. Electrospray ionization mass spectrometry determined a stoichiometry of C60@(FGGGF)4. Molecular dynamics simulations showed that the peptides assemble around the C60 cage, like a candy in its paper wrap, creating a supramolecular host able to accept C60 in the cavity. The peptide-wrapped C60 is fully biocompatible and the C60 “dark toxicity” is eliminated. C60@(FGGGF)4 shows visible light-induced reactive oxygen species (ROS) generation at physiological saline concentrations and reduction of the HeLa cell viability in response to visible light irradiation. INTRODUCTION. Dispersion of fullerenes in water is an essential step for the technological exploitation of C60 in materials science1-11 and nanomedicine.12-18 The unique chemical and physical properties of C60 will not be fully delivered until the lack of solubility of C60 in water is entirely overcome. Four strategies are commonly used to deal with the strong hydrophobicity of C60: i) mechanical dispersion–stabilization of C60. Metastable dispersions of fullerenes are obtained, but mechano-chemical treatment may often determine the surface chemical modification of C60.19 ii) chemical derivatization of the fullerene, by introduction of water-soluble substituents on the C60 cage.2o Soft derivatization processes maintain the tendency of these amphiphilic C60 derivatives to aggregate, while multiple functionalizations efficiently increases C60 solubility in water, but at the same time affects C60 peculiar properties;21 iii) use of dispersants22,23 such as surfactants, block copolymers, amphiphilic polymers, micelles and liposomes. Large quantities of C60 in water are dispersed, but the resulting solutions are polydispersions of fullerene aggregates of different sizes;23,24 iv) fullerene solvation using a supramolecular host.25 This approach produces dispersion of C60 by the synergistic interplay of hydrophobic, CH–, n- and  interactions between host and C60. Different hosts can disperse C60 in water, but the resulting complexes are usually metastable and

subsequent aggregation of the inclusion complex is common,26 especially in physiological environment. In addition, for biological and medical applications of C60, some of the hosts may be toxic and the use of fully biocompatible molecules is highly desirable. Analysis of the C60 hosts shows that two basic design principles are followed, the first is the inclusion of the molecule in a wellsuited lipophilic cavity,25 the second is the construction of bivalent, tweezer-like receptors27 with two units that recognize C60, which are connected through a spacer. The binding constants found for tweezer-like receptors are often comparable to those of the structurally more elaborate macrocyclic-type receptors thus indicating that the molecular tweezers design is an optimal strategy to disperse fullerene.27 Stable dispersions of C60 in water have been recently obtained using proteins.28-53 The interactions between aromatic residues and carbon nanomaterials are crucial for recognition.28,30,53-60 On this basis, we applied a reductionist approach to design peptidic nanotweezeers (PNTs) able to disperse C60 in water. Additional advantages of peptides over traditional supramolecular hosts reside in the fact that peptides are i) fully biocompatible, ii) already used in nanotechnology as supramolecular building blocks, and iii) synthesizable by simple and wellestablished chemistry. Aromatic molecules interact with

ACS Paragon Plus Environment

Bioconjugate Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

C60 through − stacking and the phenyl group is an ideal moiety for chemical recognition, able to interact with C60.

The UV-visible spectrum (Figure 1) of the water solution of C60@FGGGF revealed the distinctive absorption of C60 (267 and 341 nm) together with an absorption band in the

range of 400-550 nm due to the charge transfer from an electron-donor moiety (Phe residue) to C60 with formation of weak donor-acceptor complexes. The appearance of this band is typical of C60 dispersion by proteins/peptides28,29,33 and is due to the charge transfer to C60 from aromatic residues (Phe, Trp, Tyr) that compose the C60 supramolecular host. The 13C NMR (Figure S1) of the water solution of C60@FGGGF revealed the typical chemical shift of fullerene aromatic carbon at 146.1.

Scheme 1. Peptidic nanotweezeer (PNT) structures

RESULTS AND DISCUSSION. The choice as a recognition moiety fell on the phenylalanine (F) amino acidic residue while glycine (G) oligomers, Glyn (n=0-3), were selected as suitable spacers for holding the two recognizing units at the appropriate distance to bind C60 (Scheme 1). We synthesized FF, FGF, FGGF and FGGGF peptides where the terminal phenylalanine residues act as functional ligands while the glycine sequence acts as a spacer to regulate the distances between the two recognition moieties. Standard Fmocsolid phase peptide synthesis protocols were used to synthesize the four PNTs (see SI). The structures were purified by HPLC and confirmed by NMR and MS. The C60@PNT complexes were prepared using the same approach previously described for proteins.28-31 Briefly, C60 powder was sonicated, using a probe tip sonicator, in a solution of PNT. After sonication the solution was centrifuged, and the supernatant collected. The experiment was performed at different pH values (2, 7, 12) because the PNTs offer the additional advantage, with respect to the non-peptidic hosts, of a tuning of their charge state as a function of pH (PNTs are positively charged at pH 2, zwitterionic at pH 7, and negatively charged at pH 12). The presence of C60 in the water solutions was demonstrated by UV-Vis spectroscopy and 13C NMR.

In Figure 1, the results obtained by using different PNTs at various pH’s are reported. The formation of peptide-C60 supramolecular structures does not result from a single intermolecular non-covalent interactions, but pertains to the synergistic effect of various terms, including hydrogenbonding, – stacking, electrostatic, hydrophobic, and van der Waals interactions.61,62 The host-guest interaction is mainly driven by thermodynamics, but kinetics has a critical role in the structural modulation and function integration.61,62 In addition, host-guest interaction is regulated also by host-host and guest-guest tendency to self-assembly, in particular when the interactions involve peptides and C60, that show a high tendency to selfassembly. Many factors regulate the formation of C60peptide adducts. In this paper we deeply investigated the role of the pH of the solution that affects i) the global charge of the peptide, and ii) the formation of hydrogenbonds, that regulate the peptide-peptide process of selfassembly. Other factors such as temperature, that strongly affects hydrogen-bonding and hydrophobic interactions, or ionic strength that has a great impact on electrostatic interactions, can play important roles. A high pH plays a crucial role for the effective dispersion of C60. At low pH, positively charged peptides tend to disperse large aggregations of C60. The surface of C60 aggregates is negatively charged63 and positively charged peptides tend to absorb onto the C60 aggregated. At neutral pH, peptides are zwitterionic and peptides (in particular phenylalanine based peptides) have a natural tendency to self-assembly. For these pH’s, peptide-peptide interactions are favored over peptide-C60 interactions. At high pH, negatively charged peptides are able to disaggregate the C60 clusters, that are negatively charged,63 favoring monodispersion of C60 and their stability in water. The best performance in the dispersion of C60 was obtained with the FGGGF peptidic nanotweezer at a pH of 12. A full characterization of this adduct was carried out.

Figure 1. left: UV-visible spectra of FGGGF (solid line) and C60@FGGGF (dotted line); right: Quantitative dispersion of C60 by PNTs at the different pH’s, (white histograms pH 2; gray histograms pH 7; black histograms pH 12) measuring the absorbance at 341 nm.

Stability of C60@FGGGF hybrids. The analysis of the stability of the C60@FGGGF complex at different pH’s shows that the solution is perfectly stable from pH 6.5 to pH 12, while is metastable at pH lower than 4, where aggregation occurs in the timescale of a week (Figure 2a). More importantly, the C60@FGGGF complex is stable at physiological saline concentrations, (Figure 2b), while usually C60 dispersed by -cyclodextrins or nC60 rapidly

ACS Paragon Plus Environment

Page 2 of 9

Page 3 of 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Bioconjugate Chemistry precipitate.26 The C60@FGGGF solutions are stable for months both in water and in in PBS.

Figure 2. left: Absorbance measured at 341 nm of C60@FGGGF sample, upon pH variation, after 1day (black) and 1week (gray); right: UV-visible spectra of C60@FGGGF in water (black line) and in PBS (red line).

AFM imaging of C60@FGGGF hybrids. Dispersion of C60 in water is a necessary but not sufficient condition for C60 applications because the photophysical/photochemical properties of C6064-66 and its toxicity66-68 depend strictly on the nature of the fullerene dispersion. To study the aggregation state of C60@FGGGF, direct observation of the complex was conducted using atomic force microscopy (AFM) (Figure 3). The AFM images of a solution of C60@FGGGF drop-cast on a fleshly-cleaved mica surface show dot-like structure. From the height distribution analysis of the AFM images (Figure 3) a monodisperse state of C60, wrapped by peptides is visible. Control experiments were carried out using solutions of peptides at the same concentrations, that gave barely visible topographic signal.

Figure 3. AFM image of C60@FGGGF complex. left: top view, scale bar 100 nm; right: height distribution analysis of the AFM image

The AFM analysis is repeated also in the hydrated state (Figure S2) and confirms the results on dried mica, even if with a lower resolution due to the slight drift of the objects in the hydrated state. NMR characterization of C60@FGGGF hybrids. Direct proof for the formation of C60 complexes is obtained through NMR spectroscopy. We compared experiments on samples of the free peptide before and after complexation with C60. 1H NMR provides evidence of presence of supramolecular non-covalent interactions by chemical shift perturbation. Diffusion-Ordered NMR Spectroscopy, DOSY, provides evidence of complexation by variation of the translational diffusion coefficient of the peptide. Superimposition of the 1H NMR spectra, reported in Figure 4, shows a significant perturbation of the signals of the N-

terminal phenylalanine residue. The -proton chemical shift is de-shielded going from 4.19 ppm to 4.26 ppm ( = 0.07 ppm),

Figure 4. Superimposition of the 1H NMR spectra for FGGGF (red line) and C60@FGGGFn complex (cyan line).

and the -protons chemical shift moves from 3.17 ppm to 3.21 ppm ( = 0.04 ppm). At basic conditions, the Cterminal phenylalanine is negatively charged, so that it points toward the water solution, while the N-terminal phenylalanine is neutral and interacts strongly with the C60 cage. This structural arrangement is crucial to explain the data in Figure 2. In fact, the presence of a negatively charged carboxylate is critical for the stability of the C60@FGGGF hybrids. When the carboxylate group is negatively charged, it provides the necessary electrostatic repulsion to prevent aggregation/flocculation of the C60@FGGGF hybrids, while when it is neutral (pH below 4.7 for a carboxylate group) the aggregation process starts. Upon C60 binding, DOSY experiments showed an increase of 0.54 10-10m2s-1 of the translational diffusion coefficient of the FGGGF peptide (from 3.38 10-10m2s-1 to 3.92 10-10m2s-1). Such change agrees with those reported for small molecule-C60 complexes.69,70 Determination of the stoichiometry of C60@FGGGF hybrids. Based on the absorption spectra of FGGGF and C60 in water, a 4:1 stoichiometry is estimated (see SI for details). The stoichiometry of the C60@FGGGF complex was confirmed by electrospray ionization (ESI) mass spectrometry. ESI-MS analyses were carried out on FGGGF and C60@FGGGF solutions at a pH value of 12. The ESI-MS spectra of C60@FGGGF solutions (see Figure S3) shows a peak at m/z +4 = 664.0, under positive ionization conditions, corresponding to a complex of four FGGGF and a C60 (See MS fragmentation tables, Table S1 and S2 in the SI), while the peptidic signals remain similar. Larger aggregates of C60 might not “fly” in the ESI-MS under these conditions, but AFM images clearly excluded the possibility of greater aggregates. Molecular Dynamic simulation of C60@(FGGGF)4 hybrids. Molecular dynamics simulations in explicit solvent, followed by MM-GBSA analysis, were carried out to determine the geometry and the thermodynamic of binding between the peptides and C60. The peptides assemble around the C60 cage, like in a wrapped candy, creating a supramolecular cavity able to host the C60 molecule. The supramolecular structure is formed also thanks to intermolecular interaction between different

ACS Paragon Plus Environment

Bioconjugate Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

peptides, forming a -sheet like structure, (see for example in Figure 5a yellow and green peptides), that seals C60 and shields the hydrophobic fullerene cage from the water molecules. The average radius of C60@(FGGGF)4 calculated from molecular dynamics simulation (1.2 ± 0.1 nm) is in agreement with the calculated average height of C60@(FGGGF)4 measured by AFM that is 1.3 ± 0.4nm. The interaction energy (ΔGbinding) between C60 and the supramolecular host is 27.1 kcal mol-1, a very high value if compared to the 18.5 kcal mol-1 calculated using the same methodology for the interaction between lysozyme and C60.55

C60@(FGGGF)4 was estimated using the absorbance band at 341 nm. The peroxides concentration generated during irradiation (Figure 6) is plotted as the difference between the signals of the irradiated C60@(FGGGF)4 samples and that of the reference, i.e. C60@(FGGGF)4 at the same concentration, taken in dark. It appears that the generated peroxides are proportional to the concentration of C60@(FGGGF)4. The linear trend of peroxide production, as a function of C60@(FGGGF)4 concentration, supports the assignment of a monodispersed state of C60 molecules in solution. ROS production efficiency depends on C60 aggregation state. Aggregation deactivates the electronically excited states of photosensitizers, drastically decreasing the lifetime of the long-lived triplet excited state and consequently reducing the ROS production efficiency.

Figure 5. a) Geometry of the most stable conformation calculated by MM-GBSA analysis for the C60@FGGGF4 complex. b) Energy components of ΔGbinding.

In fact, the more flexible peptides, respect to a structured protein binding pocket, are able to wrap better around the C60 cage, maximizing the van der Waals interactions. Analysis of the binding components of the energy (Figure 5b) shows that van der Waals interactions are the driving force to the binding (-48.9 kcal mol−1). It is important underline that in the MM-GBSA calculations scheme, π-π interactions are included in the van der Waals term. Also hydrophobic effect, i.e., nonpolar solvation, assist the binding, (-4.9 kcal mol−1), while polar solvation (13.0 kcal mol-1) and entropy (13.8 kcal mol-1) are detrimental to the binding and their contribution is positive. ROS generation ability of C60@(FGGGF)4 in PBS buffer. C60 shows a significant visible light-induced generation of reactive oxygen species (ROS), that can be exploited in photodynamic therapy (PDT).66,71-75 However, the use of C60 molecules as photosensitizers still presents important restrictions in its application due to the: i) dependency of ROS production efficiency to the C60 aggregation state;64,65 ii) “dark toxicity” of C60 aggregates.66,76-78 The possibility of using monodispersed C60@(FGGGF)4 may overcome the current limitations. To evaluate quantitatively the photosensitizing ability of C60@(FGGGF)4, the Amplex Red assay was used to measure the generation of peroxides upon irradiation with visible light. The Amplex Red assay relies on the 1:1 stoichiometric reaction of the colorless, nonfluorescent Amplex Red (Nacetyl-3,7-dihydroxyphenoxazine) with peroxides, to form colored, fluorescent resorufin, catalyzed by horseradish peroxidase (HRP). The ability of C60@(FGGGF)4 to generate peroxides in PBS at different concentrations was investigated (Figure 6). The concentration of

Figure 6. Peroxides generated upon visible light irradiation using different concentrations of C60@(FGGGF)4

When C60 aggregates are present, the aggregation state of C60 is usually concentration dependent.64,65 At higher concentrations, there should be formation of larger aggregates, decreasing ROS production.64,65 On the opposite, whenC60 is present as a monomer, there should be, as observed experimentally, a monotonic increase in the peroxide concentration. The definitive evidence for the existence of C60 as a monomer can be provided by measuring the yield of singlet oxygen generation by the C60@(FGGGF)4.The quantum yield (QY) of singlet oxygen generation by C60@(FGGGF)4 was determined by measuring the near-infrared phosphorescence spectra originated by the spin-forbidden radiative deactivation of the lowest singlet electronic excited state to the triplet electronic ground state of oxygen and by comparing it with the standard: Bengal Rose (BR,QY=0.75 in D2O solution).79 The phosphorescence spectra of the C60@(FGGGF)4 and of the reference BR, both with the same absorbance at the excitation wavelength (exc=514 nm) and buffered at pH 7.4, are shown in Figure 7. In perfect accordance with previous works, the singlet oxygen emission sensitized by Bengal Rose shows a maximum at ≈1270 nm,80 while the emission generated by C60@(FGGGF)4 is shifted of ≈10 nm toward longer wavelengths. This shift is caused by the different local properties of the environment where singlet excited state is formed.81 According to the spectra of Figure 7, the measured quantum yield for the C60@(FGGGF)4 is

ACS Paragon Plus Environment

Page 4 of 9

Page 5 of 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Bioconjugate Chemistry 0.71, very close to that of BR, a molecule which is considered as one of the best photosensitizers for singlet oxygen generation. The yield of singlet oxygen is very high, confirming the high performances of C60@(FGGGF)4 in the visible light-induced generation of ROS and indirectly its existence as a monomer in solution.

manner, when irradiated (Figure 8). The results show that the cell mortality rate is related to the concentration of the photosensitizer present in the cell medium during incubation. As the concentration of C60@(FGGGF)4 increases, the cell mortality increases, confirming the ability of C60@(FGGGF)4 to generate ROS in a concentration-dependent manner. CONCLUSION For the first time a C60 monodispersion, stable in physiological environments, was obtained by wrapping C60 cage with peptides. The C60@(FGGGF)4 host-guest complex satisfies all the crucial requirements for the dispersion of fullerene in water: i) high solubility and stability of the C60 adduct, ii) monodispersion of C60, iii) high ΔGbinding, iv) dispersion by a biocompatible host.

Figure 7. Emission spectra from singlet oxygen generated upon excitation at 514 nm for solutions with the same absorbance (514 nm) of Rose Bengale (red line) and C60@(FGGGF)4 (black line).

Determination of cytotoxicity and phototoxicity upon visible light irradiation of C60@(FGGGF)4 hybrids in HeLa cells To assess in vitro the cytotoxicity of C60@(FGGGF)4 and phototoxicity upon irradiation, the ability of the hybrid to inhibit growth and induce cell death in dark condition and upon photoexcitation with visible light was tested. HeLa cells, a highly proliferative in vitro human cancer model, were used. Figure 8 shows that no significative reduction in cell viability was observed for HeLa cells in dark conditions, even at high C60 concentration (50 M). The C60@(FGGGF)4 hybrids are perfectly biocompatible and do not show “dark toxicity”.

The absence of dark toxicity of the C60@(FGGGF)4 and the preservation of the photophysical properties of C60, including the ability to generate ROS upon irradiation, indicate the potential of this hybrid as an innovative agent for photodynamic therapy. The peptidic nature of the host will allow its easy functionalization without modify the pristine fullerene, opening new and exciting opportunities for technological applications of the peptide-C60 hybrid such as the controlled assembly of C60 on surfaces,82,83 the targeting of C60 molecules to selected cells84,85 or the use of multicomponent self-assembled peptide materials for PDT.86-88

ASSOCIATED CONTENT Supporting Information. 13C spectra of FGGGF and C60@FGGGF; AFM image of C60@FGGGF complex in hydrated state, ESI-MS of FGGGF and C60@FGGGF; Experimental Section and Computational details. The Supporting Information is available free of charge on the ACS Publications website. AUTHOR INFORMATION Corresponding Author

* [email protected] (A. T.); * [email protected] (M. C.)

ACKNOWLEDGMENT Matteo Di Giosia was supported by a FIRC-AIRC fellowship for Italy (id. 22318). This study was supported by the Italian Ministry of Education, University and Research (MIUR), SIR Programme no. RBSI149ZN9−BIOTAXI funded to MC. Figure 8. Effect on cell viability upon photoirradiation. Samples in dark conditions (black bars) or upon visible light irradiation (grey bars) at different C60@(FGGGF)4 concentrations. Each value represents the ± mean value standard deviation (SD) of three replicates.

In contrast, the presence of C60@(FGGGF)4 caused an increase of the mortality of HeLa cells in a dose dependent

REFERENCES (1) Prato, M. (1997) [60]Fullerene Chemistry for Materials Science Applications. J. Mater. Chem. 7, 1097-1109. (2) Wudl, F. (2002) Fullerene Materials. J. Mater. Chem. 12, 1959-1963. (3) Montellano López, A., Mateo-Alonso, A., Prato, M. (2011)

ACS Paragon Plus Environment

Bioconjugate Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Materials Chemistry of Fullerene C60 Derivatives. J. Mater. Chem. 21, 1305-1318. (4) Guldi, D. M., Illescas, B. M., Atienza, C. M., Wielopolski, M., Martín N. (2009) Fullerene for Organic Electronics. Chem. Soc. Rev. 38, 1587-1597. (5) Bonifazi, D., Enger, O., Diederich, F. (2007) Supramolecular [60]Fullerene Chemistry on Surfaces. Chem. Soc. Rev. 36, 390-414. (6) Babu, S. S., Möhwald, H., Nakanishi, T. (2010) Recent Progress in Morphology Control of Supramolecular Fullerene Assemblies and its Applications. Chem. Soc. Rev. 39, 4021-4035. (7) Kirner, S.; Sekita, M.; Guldi, D. M. (2014) 25th Anniversary Article: 25 Years of Fullerene Research in Electron Transfer Chemistry. Adv. Mater. 26, 1482-1493. (8) A. Mateo-Alonso, D. M. Guldi, F. Paolucci, M. Prato, (2007) Fullerenes: Multitask Components in Molecular Machinery. Angew. Chem. Int. Ed. 46, 8120-8126. (9) Sherigara, B. S.; Kutner, W.; D’Souza, F. (2003) Electrocatalytic Properties and Sensor Applications of Fullerenes and Carbon Nanotubes. Electroanalysis 15, 753-772. (10) Nierengarten, J.-F. (2004) Chemical Modification of C60 for Materials Science Applications. New J. Chem. 28, 1177-1191. (11) Collavini, S.; Delgado, J. L. (2018) Fullerenes: The Stars of Photovoltaics. Sustainable Energy Fuels, DOI:10.1039/C8SE00254A. (12) Goodarzi, S.; Da Ros, T.; Conde, J.; Sefat, F.; Mozafari, M. (2017) Fullerene: Biomedical Engineers Get to Revisit an Old Friend. Mater. Today 20, 460-480. (13) Nakamura, E., Isobe, H. (2003) Functionalized Fullerenes in Water. The First 10 Years of Their Chemistry, Biology, and Nanoscience. Acc. Chem. Res. 36, 807-815. (14) Castro, E., Garcia, A. H., Zavala, G., Echegoyen, L. (2017) Fullerenes in Biology and Medicine. J. Mater. Chem. B 5, 65236535. (15) Dellinger, A., Zhou, Z., Connor, J., Madhankumar, A., Pamujula, S., Sayes, C. M., Kepley, C. L., (2013) Application of Fullerenes in Nanomedicine: An Update. Nanomedicine 8, 11911208. (16) R. Partha, J. L. Conyers, (2009) Biomedical Applications of Functionalized Fullerene-Based Nanomaterials. Int. J. Nanomedicine 4, 261-275. (17) Bosi, S.; Da Ros, T.; Spalluto, G.; Prato, M. (2003) Fullerene Derivatives: An Attractive Tool for Biological Applications. Eur. J. Med. Chem. 38, 913-923. (18) Montellano, A., Da Ros, T., Bianco, A., Prato, M. (2011) Fullerene C60 as a Multifunctional System for Drug and Gene Delivery Nanoscale, 2011, 3, 4035-4041. (19) Todorovic Markovic, B., Jokanovic, V., Jovanovic, S., Kleut, D., Dramicanin, M., Markovic, Z. (2009) Surface Chemical Modification of Fullerene by Mechanochemical Treatment. Appl. Surf. Sci. 255, 7537-7541. (20) Hirsch, A., Brettreich, M. (2005) Fullerenes: Chemistry and Reactions; Wiley-VCH Verlag GmbH & Co. KGaA: Weinheim, Germany. (21) Guldi, D. M., Prato, M. (2000) Excited-State Properties of C60 Fullerene Derivatives. Acc. Chem. Res. 33, 695-703. (22) Ikeda, A. (2013) Water-Soluble Fullerenes Using Solubilizing Agents, and Their Applications. J. Incl. Phenom. Macrocycl. Chem. 77, 49-65. (23) Dallavalle, M., Leonzio, M., Calvaresi, M., Zerbetto, F. (2014) Explaining Fullerene Dispersion by using Micellar Solutions. ChemPhysChem 15, 2998-3005. (24) Torres, V. M., Posa, M., Srdjenovic, B., Simplício, A. L. (2011) Solubilization of Fullerene C60 in Micellar Solutions of Different Solubilizers. Colloids Surf. B 82, 46-53.

(25) Canevet, D., Pérez, E. M., Martín, N. (2011) Wraparound Hosts for Fullerenes: Tailored Macrocycles and Cages. Angew. Chemie Int. Ed. 50, 9248-9259. (26) Van Guyse, J. F. R., de la Rosa, V. R., Hoogenboom, R. (2018) Mechanochemical Preparation of Stable Sub-100 nm Cyclodextrin: Buckminsterfullerene (C60) Nanoparticles by Electrostatic or Steric Stabilization Chem. Eur. J. 24, 2758-2766. (27) Pérez, E. M., Martín, N. (2010) Molecular Tweezers for Fullerenes. Pure Appl. Chem. 82, 523-533. (28) Calvaresi, M.; Arnesano, F.; Bonacchi, S.; Bottoni, A.; Calò, V.; Conte, S.; Falini, G.; Fermani, S.; Losacco, M.; Montalti, M.; Natile, G.; Prodi, L.; Sparla, F.; Zerbetto, F. (2014) C60@Lysozyme: Direct Observation by Nuclear Magnetic Resonance of a 1:1 Fullerene Protein Adduct. ACS Nano 8, 1871-1877. (29) Soldà, A.; Cantelli, A.; Di Giosia, M.; Montalti, M.; Zerbetto, F.; Rapino, S.; Calvaresi, M. (2017) C60@Lysozyme: A New Photosensitizing Agent for Photodynamic Therapy. J. Mater. Chem. B 5, 6608-6615. (30) Di Giosia, M.; Valle, F.; Cantelli, A.; Bottoni, A.; Zerbetto, F.; Calvaresi, M. (2018) C60 Bioconjugation with Proteins: Towards a Palette of Carriers for All pH Ranges. Materials 11, 691. (31) Di Giosia, M.; Bomans, P. H. ; Bottoni, A.; Cantelli, A.; Falini, G.; Franchi, P.; Guarracino, G.; Friedrich, H.; Lucarini, M.; Paolucci, F.; Rapino, S.; Sommerdijk, N. A. J. M.; Soldà, A.; Valle, F.; Zerbetto, F.; Calvaresi, M. (2018) Proteins as Supramolecular Hosts For C60: A True Solution of C60 in Water. Nanoscale 10, 9908-9916. (32) Hasunuma,N., Kawakami, M., Hiramatsu, H., Nakabayashi, T. (2018) Preparation and Photo-Induced Activities of Watersoluble Amyloid -C60 Complexes. RSC Adv. 8, 1784717853. (33) Kim, K.-H., Ko, D.-K., Kim, Y.-T., Kim, N. H., Paul, J. Zhang, S.-Q., Murray, C. B., Acharya, R., DeGrado, W. F., Kim, Y. H., Grigoryan, G. (2016) Protein-Directed Self-Assembly of a Fullerene Crystal. Nat. Commun. 7, 11429 (34) Vance, S. J., Desai, V., Smith, B. O., Kennedy M. W., Cooper, A. (2016) Aqueous Solubilization of C60 Fullerene by Natural Protein Surfactants, Latherin and Ranaspumin-2. Biophys. Chem. 214–215, 27-32. (35) Zanzoni, S., Ceccon, A., Assfalg, M., Singh, R. K., Fushman, D., D’Onofrio, M. (2015) Polyhydroxylated [60]Fullerene Binds Specifically to Functional Recognition Sites on a Monomeric and a Dimeric Ubiquitin. Nanoscale 7, 7197−7205. (36) Miao, Y., Xu, J., Shen, Y., Chen, L., Bian, Y., Hu, Y., Zhou, W., Zheng, F., Man, N., Shen, Y., Zhang, Y., Wang, M., Wen, L. (2014) Nanoparticle as Signaling Protein Mimic: Robust Structural and Functional Modulation of CaMKII upon Specific Binding to Fullerene C60 Nanocrystals. ACS Nano 8, 6131−6144. (37) Chen, P., Seabrook, S. A., Epa, V. C., Kurabayashi, K., Barnard, A. S., Winkler, D. A., Kirby, J. K., Ke, P. C. (2014) Contrasting Effects of Nanoparticle Binding on Protein Denaturation. J. Phys. Chem. C 118, 22069. (38) Zhen, M., Zheng, J., Ye, L., Li, S., Jin, C., Li, K., Qiu, D., Han, H., Shu, C., Yang, Y., Wang, C. (2012) Maximizing the Relaxivity of Gd-Complex by Synergistic Effect of HSA and Carboxylfullerene. ACS Appl. Mater. Interfaces 4, 3724−3729. (39) Wu, H., Lin, L., Wang, P., Jiang, S., Dai, Z., Zou, X. (2011) Solubilization of Pristine Fullerene by the Unfolding Mechanism of Bovine Serum Albumin for Cytotoxic Application. Chem. Commun. 47, 10659−10661. (40) Ratnikova, T. A., Govindan, P. N., Salonen, E., Ke, P. C. (2011) In Vitro Polymerization of Microtubules with a Fullerene Derivative. ACS Nano 5, 6306−6314. (41) Maoyong, S., Guibin, J., Junfa, Y., Hailin, W. (2010) Inhibition of Polymerase Activity by Pristine Fullerene Nanoparticles Can Be Mitigated by Abundant Proteins. Chem. Commun. 46, 1404-1406.

ACS Paragon Plus Environment

Page 6 of 9

Page 7 of 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Bioconjugate Chemistry (42) Innocenti, A., Durdagi, S., Doostdar, N., Strom, A. T., Barron, A. R., Supuran, C. T. (2010) Nanoscale Enzyme Inhibitors: Fullerenes Inhibit Carbonic Anhydrase by Occluding the Active Site Entrance. Bioorg. Med. Chem. 18, 2822−2828. (43) Durdagi, S., Supuran, C. T., Strom, T. A., Doostdar, N., Kumar, M. K., Barron, A. R., Mavromoustakos, T., Papadopoulos, M. G. (2009) In Silico Drug Screening Approach for the Design of Magic Bullets: A Successful Example with Anti-HIV Fullerene Derivatized Amino Acids. J. Chem. Inf. Model. 49, 1139−1143. (44) Yang, S.-T., Wang, H., Guo, L., Gao, Y., Liu, Y., Cao, A. (2008) Interaction of Fullerenol with Lysozyme Investigated by Experimental and Computational Approaches. Nanotechnology 19, 395101. (45) Zhang, X., Shu, C., Xie, L., Wang, C., Zhang, Y., Xiang, J., Li, L., Tang, Y. (2007) Protein Conformation Changes Induced by a Novel Organophosphate-Containing Water-Soluble Derivative of a C60 Fullerene Nanoparticle. J. Phys. Chem. C 111, 14327−14333. (46) Qu, X., Komatsu, T., Sato, T., Glatter, O., Horinouchi, H., Kobayashi, K., Tsuchida, A. (2008) Structure, Photophysical Property, and Cytotoxicity of Human Serum Albumin Complexed with Tris(dicarboxymethylene)[60]Fullerene. Bioconjugate Chem. 19, 1556–1560 (47) Belgorodsky, B., Fadeev, L., Kolsenik, J., Gozin, M. (2007) Biodelivery of a Fullerene Derivative. Bioconjugate Chem. 18, 10951100. (48) Pastorin, G., Marchesan, S., Hoebeke, J., Da Ros, T., EhretSabatier, L., Briand, J.-P., Prato, M., Bianco, A. (2006) Design and Activity of Cationic Fullerene Derivatives as Inhibitors of Acetylcholinesterase. Org. Biomol. Chem. 4, 2556−2562. (49) Belgorodsky, B., Fadeev, L., Kolsenik, J., Gozin, M. (2006) Formation of a Soluble Stable Complex between Pristine C60Fullerene and a Native Blood Protein. ChemBioChem 7, 1783−1789. (50) Belgorodsky, B.; Fadeev, L.; Ittah, V.; Benyamini, H.; Zelner, S.; Huppert, D.; Kotlyar, A. B.; Gozin, M. Formation and Characterization of Stable Human Serum Albumin−Tris-malonic Acid [C60]Fullerene Complex. Bioconjugate Chem. 2005, 16, 1058−1062. (51) Mashino, T., Shimotohno, K., Ikegami, N., Nishikawa, D., Okuda, K., Takahashi, K., Nakamura, S., Mochizuki, M. (2005) Human Immunodeficiency Virus-Reverse Transcriptase Inhibition and Hepatitis C Virus RNA-Dependent RNA Polymerase Inhibition Activities of Fullerene Derivatives. Bioorg. Med. Chem. Lett. 15, 1107-1109. (52) Park, K. H., Chhowalla, M., Iqbal, Z., Sesti, F. (2003) SingleWalled Carbon Nanotubes are a New Class of Ion Channel Blockers. J. Biol. Chem. 278, 50212−50216. (53) Liu, Y., Yan, B., Winkler, D. A., Fu, J., Zhang, A. (2017) Competitive Inhibition Mechanism of Acetylcholinesterase without Catalytic Active Site Interaction: Study on Functionalized C60 Nanoparticles via in Vitro and in Silico Assays. ACS Appl. Mater. Interfaces 9, 18626-18638. (54) Calvaresi, M., Furini, S., Domene, C., Bottoni, A., Zerbetto, F. (2015) Blocking the Passage: C60 Geometrically Clogs K+ Channels. ACS Nano 9, 4827-4834. (55) Calvaresi, M., Bottoni, A., Zerbetto, F. (2015) Thermodynamics of Binding Between Proteins and Carbon Nanoparticles: The Case of C60@Lysozyme. J. Phys. Chem. C 119, 28077-28082. (56) L. Ahmed, B. Rasulev, S. Kar, P. Krupa, M. A. Mozolewskae, J. Leszczynski, Inhibitors or Toxins? (2017) Large Library TargetSpecific Screening of Fullerene-Based Nanoparticles for Drug Design Purpose. Nanoscale 9, 10263-10276. (57) Calvaresi, M., Zerbetto, F. (2010) Baiting Proteins with C60 ACS Nano 4, 2283-2299. (58) Benyamini, H., Shulman-Peleg, A., Wolfson, H. J.; Belgorodsky, B.; Fadeev, L., Gozin, M. (2006) Interaction of C60-

Fullerene and Carboxyfullerene with Proteins: Docking and Binding Site Alignment. Bioconjugate Chem. 17, 378-386. (59) Trozzi, F., Marforio, T. D., Bottoni, A., Zerbetto, F., Calvaresi, M. (2017) Engineering the Fullerene-protein Interface by Computational Design: The Sum is More than its Parts. Isr. J. Chem. 57, 547-552. (60) De Leo, F., Magistrato, A., Bonifazi, D. (2015) Interfacing Proteins with Graphitic Nanomaterials: From Spontaneous Attraction to Tailored Assemblies. Chem. Soc. Rev. 44, 6916-6953. (61) Wang, J., Liu, K., Xing, R., Yan, X.(2016) Peptide SelfAssembly: Thermodynamics and Kinetics. Chem. Soc. Rev. 45, 5589-5604 (62) Yuan, C., Li, S., Zou, Q., Ren, Y., Yan, X. (2017) Multiscale Simulations for Understanding the Evolution and Mechanism of Hierarchical Peptide Self-Assembly. Phys. Chem. Chem. Phys. 19, 23614-23631 (63) Deguchi, S., Alargova, R. G., Tsujii, K. (2001) Stable Dispersions of Fullerenes, C60 and C70, in Water. Preparation and Characterization. Langmuir 17, 6013-6017 (64) Hotze, E. M., Labille, J., Alvarez, p., Wiesner, M. R. (2008) Mechanisms of Photochemistry and Reactive Oxygen Production by Fullerene Suspensions in Water. Environ. Sci. Technol., 2008, 42, 4175–4180. (65) Lee, J., Fortner, J. D., Hughes, H. B., Kim, J.-H. (2007) Photochemical Production of Reactive Oxygen Species by C60 in the Aqueous Phase During UV Irradiation. Environ. Sci. Technol. 41, 2529–2535 (66) Trpkovic, A., Todorovic-Markovic, B., Trajkovic, V. (2012) Toxicity of Pristine Versus Functionalized Fullerenes: Mechanisms of Cell Damage and the Role of Oxidative Stress. Arch. Toxicol. 86, 1809-1827. (67) Lyon, D. Y., Adams, L. K., Falkner, J. C., Alvarez, P. J. J. (2006) Antibacterial Activity of Fullerene Water Suspensions:  Effects of Preparation Method and Particle Size. Environ. Sci. Technol. 40, 4360–4366 (68) Chae, S.-R., Badireddy, A. R., Budarz, J. F., Lin, S., Xiao, Y., Therezien, M., Wiesner, M. R. (2010) Heterogeneities in Fullerene Nanoparticle Aggregates Affecting Reactivity, Bioactivity, and Transport, ACS Nano 4, 5011-5018. (69) Prylutskyy, Y. I., Evstigneev, M. P., Pashkova, I. S., Wyrzykowski, D., Woziwodzka, A., Gotunski, G., Piosik, J., Cherepanov, V. V., Ritterg, U. (2014) Characterization of C60 Fullerene Complexation with Antibiotic Doxorubicin. Phys. Chem. Chem. Phys. 16, 23164-23172. (70) Mosunov, A. A., Pashkova, I. S., Sidorova, M., Pronozin, A., Lantushenko, A. O., Prylutskyy, Y. I., Parkinson, J. A., Evstigneev, M. P. (2017) Determination of the Equilibrium Constant of C60 Fullerene Binding with Drug Molecules. Phys. Chem. Chem. Phys. 19, 6777-6784. (71) Markovic, Z., Trajkovic, V. (2008) Biomedical Potential of the Reactive Oxygen Species Generation and Quenching by Fullerenes (C60). Biomaterials 29, 3561-3573. (72) Burlaka, A. P., Sidorik, Y. P., Pryluska, S. V., Matyshevska, O. P., Colub, O. A., Prylutskyy, Y. I., Scharff, P. (2004) Catalytic System of the Reactive Oxygen Species on the C60 Fullerene Basis. Exp. Oncol. 26, 326-327. (73) Mroza, P., Tegosa, G. P., Galic, H., Whartonc, T., Sarnad, T., Hamblin, M. R. (2007) Photodynamic Therapy with Fullerenes. Photochem. Photobiol. Sci. 6, 1139-1149. (74) Hamblin, M. R. (2018) Fullerenes as Photosensitizers in Photodynamic Therapy: Pros and Cons. Photochem. Photobiol. Sci., DOI:10.1039/C8PP00195B. (75) Antok, D., Sugikawa, K., Ikeda, A. (2018) Photodynamic Activity of Fullerene Derivatives Water-Solubilized by Natural Product-Based Solubilizing Agents. Chem. Eur. J. DOI:10.1002/chem.201803657.

ACS Paragon Plus Environment

Bioconjugate Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(76) Sayes, C. M., Fortner, J. D., Guo, W., Lyon, D., Boyd, A. M., Ausman, K. D., Tao, Y. J., Sitharaman, B., Wilson, L. J., Hughes, J. B., West, J. L., Colvin, V. L. (2004) The Differential Cytotoxicity of Water-Soluble Fullerenes. Nano Lett. 4, 1881-1887. (77) Isakovic, A.; Markovic, Z.; Todorovic-Markovic, B.; Nikolic, N., Vranjes-Djuric, S., Mirkovic, M., Dramicanin, M., Harhaji, L., Raicevic, N., Nikolic, Z., Trajkovic, V. (2006) Distinct Cytotoxic Mechanisms of Pristine versus Hydroxylated Fullerene. Toxicol. Sci. 91, 173-183, (78) Markovic, Z., Todorovic-Markovic, B., Kleut, D., Nikolic, N., Vranjes-Djuric, S., Misirkic, M., Vucicevic, L., Janjetovic, K., Isakovic, A., Harhaji, L., Babic-Stojic, B., Dramicanina, M., Trajkovic, V. (2007) The Mechanism of Cell-Damaging Reactive Oxygen Generation by Colloidal Fullerenes. Biomaterials 28, 54375448. (79) Bilski, P., Dabestani, R., Chignell, C. F. (1991) Influence of Cationic Surfactant on the Photoprocesses of Eosine and Rose Bengal in Aqueous Solution. J. Phys. Chem. 95, 5784-5791 (80) Bromberg, A., Foote, C. S. (1989) Solvent Shift of Singlet Oxygen Emission Wavelength. J. Phys. Chem. 93, 3968-3969 (81) Macpherson, A. N., Truscott, T. G., Turner, P. H. (1994) Fourier-Transform Luminescence Spectroscopy of Solvated Singlet Oxygen. J. Chem. Soc. Faraday Trans. 90, 1065-1072 (82) Fujii, S., Morita, T., Kimura, S. (2007) Fabrication of Langmuir–Blodgett Film of a Fullerene Derivative with a Cyclic Peptide as an Anchor. Bioconjugate Chem. 18, 1855-1859. (83) Nednoor, P., Capaccio, M., Gavalas, V. G., Meier, M. S., Anthony, J. E., Bachas, L. G. (2004) Hybrid Nanoparticles Based

on Organized Protein Immobilization on Fullerenes. Bioconjugate Chem. 15, 12-15 (84) Ashcroft, J. M., Tsyboulski, D. A., Hartman, K. B., Zakharian, T. Y., Marks, J. W., Weisman, R. B., Rosenblum, M. G., Wilson, L. J. (2006) Fullerene (C60) Immunoconjugates: Interaction of Water-Soluble C60 Derivatives with the Murine Anti-gp240 Melanoma Antibody. Chem. Commun. 0, 3004-3006. (85) Barron, A. R. (2016) [60]Fullerene-Peptides: Bio-Nano Conjugates With Structural and Chemical Diversity. J. Enzyme Inhib. Med. Chem. 31, 164-176. (86) Liu, K., Xing, R., Zou, Q., Ma, G., Mçhwald, H., Yan, X. (2016) Simple Peptide-Tuned Self-Assembly of Photosensitizers towards Anticancer Photodynamic Therapy Angew. Chem. Int. Ed. 55, 3036 –3039 (87) Abbas, M., Zou, Q., Li, S., Yan, X. (2017) Self-Assembled Peptide- and Protein-Based Nanomaterials for Antitumor Photodynamic and Photothermal Therapy. Adv. Mater. 29, 1605021 (88) Li, S., Zou, Q., Li, Y., Yuan, C., Xing, R., Yan, X. (2018) Smart Peptide-Based Supramolecular Photodynamic MetalloNanodrugs Designed by Multicomponent Coordination SelfAssembly. J. Am. Chem. Soc. 140, 10794−10802.

ACS Paragon Plus Environment

Page 8 of 9

Page 9 of 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Bioconjugate Chemistry

Table of Contents artwork

ACS Paragon Plus Environment

9