Subscriber access provided by READING UNIV
Article
Natural Honeycomb Flavone Chrysin (5 7-dihydroxyflavone) Reduced Graphene Oxide Nanosheets Fabrication for Improved Bactericidal and Skin Regeneration Sathishkumar G, Premkumar P, Pradeep K Jha, Jeyaraj M, Manikandan K, Asif Mohammed Khan M, and Sivaramakrishnan S ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/ acssuschemeng.7b02603 • Publication Date (Web): 27 Oct 2017 Downloaded from http://pubs.acs.org on November 1, 2017
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 free 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 accessible to all readers and 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.
ACS Sustainable Chemistry & Engineering 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 50
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
ACS Sustainable Chemistry & Engineering
1
Natural Honeycomb Flavone Chrysin (5 7-
2
dihydroxyflavone) Reduced Graphene Oxide Nanosheets
3
Fabrication for Improved Bactericidal and Skin
4
Regeneration
5 6
Sathishkumar G†, Premkumar P§, Pradeep K Jha‡, Jeyaraj M⊥, Manikandan K∥, Asif Mohammed
7
Khan M†, Sivaramakrishnan S†*
8 9 10 11 12 13 14 15 16 17 18 19
†
Department of Biotechnology, Bharathidasan University, Tiruchirappalli-620024, Tamilnadu, India. § Department of Biochemistry, Bharathidasan University, Tiruchirappalli-620024, Tamilnadu, India. ‡ School of Medical Science and Technology, Indian Institute of Technology, Kharagpur-721302, West Bengal, India. ⊥National Centre for Nanosciences and Nanotechnology, University of Madras, Guindy campus, Chennai 600025, India. ∥Nonlinear Optical Materials Laboratory, School of Physics, Bharathidasan University, Tiruchirappalli-620024, Tamilnadu, India.
20 21 22 23 24 25
Corresponding author*
26
Tel: 0431-2407086: Fax: 0431-2407045
27
Email:
[email protected] (S.Sivaramakrishnan)
28
ACS Paragon Plus Environment
ACS Sustainable Chemistry & Engineering
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
29
ABSTRACT
30
Functionalization of the biocompounds on nanomaterials surface will decrease their
31
detrimental side effects and escapes them from immunological rejection. In this study, we
32
developed a sustainable green chemistry route to fabricate natural honeycomb flavone chrysin (5,
33
7-dihydroxyflavone ChR) reduced graphene oxide nanosheets (ChR-rGONSs) using a simple
34
experimental set-up. The hydroxyl (O-H) functional group of ChR wires the reduction and
35
generation of functionalized ChR-rGONSs, and it was characterized through Raman, Fourier
36
transform infrared (FT-IR) and X-ray photo electron (XPS) spectroscopic analysis. Effective
37
reduction of graphene oxide (GO) into ChR-rGONSs was further revealed with X-ray Diffraction
38
(XRD), atomic force microscope (AFM), field emission scanning electron microscopic (FE-
39
SEM) measurements. Using the high resolution transmission electron microscopic (HR-TEM)
40
images, Zeta potential, and Energy dispersive X-ray spectroscopic (EDAX) analysis we have
41
shown the fine morphological features, surface charge and stableness of fabricated ChR-
42
rGONSs. Thermo-stable properties of ChR-rGONSs were much greater than ChR and GO. In
43
disc diffusion study, the ChR-rGONSs showed an excellent inhibitory action against 11 bacterial
44
pathogens comparatively with raw graphite (G), free ChR and GO which clearly depicts their
45
enhanced antimicrobial value. Moreover, in vivo studies were proved that the ChR-rGONSs
46
promotes rapid skin regeneration and wound closure action relatively with other treatments such
47
as raw-G, GO, and free ChR. The ChR-rGONSs were exhibited no signs of toxicity against
48
treated animal model, also causes less RBCs lysis which represents their biocompatibility for
49
direct wound dressing and other regenerative medicine applications.
50
ACS Paragon Plus Environment
Page 2 of 50
Page 3 of 50
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
ACS Sustainable Chemistry & Engineering
51
KEYWORDS: Green chemistry, Chrysin (5, 7-dihydroxyflavone ChR), Reduced graphene
52
oxide, Wound healing, Bactericidal, X-ray Photoelectron Spectroscopy
53
ACS Paragon Plus Environment
ACS Sustainable Chemistry & Engineering
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
54
INTRODUCTION
55
Multifaceted two-dimensional (2D) graphene sheet bonded with sp2 carbon atoms was
56
considered as an important nanomaterial because of its outstanding optical, electronic,
57
mechanical, and catalytic properties1. Especially, the Graphene oxide (GO) possess unique
58
operative physical, chemical and biological properties, as it possess oxygenated functional
59
groups2. Also, the GO was receiving huge importance on account of its easy availability,
60
dispersity, flexibility for chemical reaction, tunable surface chemistry and a high-level
61
biocompatibility. This prominent material was employed for wide spectrum of biomedical
62
applications such as biosensing3, drug/gene delivery4, phototherapy5, imaging6, tissue
63
engineering7, regenerative medicine8 and theranostics9. Reduced GO (rGO) nanosheets
64
hybridized with oxygen-containing chemical groups have gained colossal interests because of
65
their exclusive surface properties. The active functional groups such as epoxy, hydroxyl, and
66
carboxyl makes GO an important nanomaterial to carry the active ‘payloads’ such as drugs and
67
molecules10.
68
Conventional methodologies to fabricate rGO nanosheets were involved with the
69
utilization of toxic chemical reductants like hydrazines and sodium borohydride11. Most of these
70
reducing agents and their resultant by-products were unsafe to environment as well as life forms,
71
which makes them not suitable for scaled-up production and further bio-related applications12.
72
Therefore, there was a growing demand to find an alternative facile green chemistry route for
73
reduced GONSs fabrication. Diverse new and eco-friendlier reducing agents such as, vitamin
74
C13,14, amino acids15, alkyl amines16, sugar17, glucose18, bovine serum albumin19, hydrogen-rich
75
water20, metal nanoparticles21 and powders22, supercritical alcohols23, polyphenols of green
76
tea24,25, ginseng26, bacteria27,28, baker’s yeast29, wild carrot root30, and phytoextract31 were
ACS Paragon Plus Environment
Page 4 of 50
Page 5 of 50
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
ACS Sustainable Chemistry & Engineering
77
reported as the potential replacement of toxic reductants. Apart from this, few other sustainable
78
methods to fabricate reduced GO nanosheets were flash photo reduction32, laser reduction33,
79
catalytic34 and photocatalytic35-41. However, understanding the mechanism of reduction and
80
toxicological insights of bio-based rGONSs were very much important for their applications. As
81
for as our knowledge this might be the maiden report where a single dietary flavone Chrysin (5,
82
7- dihydroxyflavone ChR) has been utilized to convert GO into sole rGO nanosheets, also it
83
represents a comprehensive view on the mechanistic aspects of green chemistry synthesis.
84
Natural bioactive dietary flavone Chrysin (5, 7- dihydroxyflavone ChR) was commonly
85
found in different bio entities including honeycomb and propolis owns remarkable antimicrobial,
86
anti-inflammatory, antioxidant, anticancer, hepatoprotective and anti-diabetic effects42. It was
87
widely consumed as a steroid supplement by male bodybuilders for large muscle development,
88
because it hinders the participation of aromatase in estrogens biosynthesis. An interesting
89
advantage of ChR was it actively scavenges the free-radicals and act against various factors of
90
aging related disorders43,44. The anti-inflammatory activity of ChR was noteworthy, as it holds an
91
ability to suppress the Cyclooxygenase-2 enzyme level45.
92
Nevertheless, ChR possesses diverse biological activities it always suffers with certain
93
limitations such as poor solubility, bioavailability and dose-limiting detrimental side effects46. In
94
general, flavones were well known for their extraordinary antioxidant potentials due to the active
95
hydroxyl and ketone functional groups. They also holds an ability to combat against oxidative
96
stress associated diseases like cancer, diabetes, cardiovascular and neurological disorders47.
97
Surface functionalization or capping of these active flavonoids with nano-graphene oxide sheets
98
will eventually improve their solubility, cellular permeability, bioavailability and compatibility
99
for value added biomedical applications.
ACS Paragon Plus Environment
ACS Sustainable Chemistry & Engineering
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
100
Wound healing and remodeling comprises with a number of intrinsic cell as well as
101
molecular cascades which ensues in four major stages such as hemostatic, inflammatory, re-
102
epithelialization or proliferative and restoration48. The pathological process of skin regeneration
103
begins with epidermis and keratinocytes reproduction followed by the contraction of
104
extracellular matrix (ECM). Presence of valuable flavonoids such as chrysin, kaempferol,
105
apigenin, pinocembrin, galangin, hesperetin, and quercetin in the honey and its by-products
106
significantly upsurges the ECM components at initial stages of wound repair. Also, it triggers the
107
production of a major cytokine i.e. transforming growth factor beta (TGF-β) which partakes an
108
important role in hemostasis and inflammation49. Generally, Oxygen was considered as the major
109
requirement to disinfect wounds, fuel hauling, redox signals, and actively participates in repair
110
cascade of physical trauma50. Hence, in this work we present a facile green chemistry method to
111
fabricate ChR-rGONSs using the honeycomb flavone Chrysin (5 7-dihydroxyflavone) for
112
biomedical applications.
113 114
EXPERIMENTAL DETAILS
115
Materials
116
Graphite flakes
