Polyelectrolyte Complex Nanoparticles from Chitosan and Acylated

Subscriber access provided by UNIV OF DURHAM

Article

Polyelectrolyte complex nanoparticles from chitosan and acylated rapeseed cruciferin protein for curcumin delivery Fengzhang Wang, Yijie Yang, Xingrong Ju, Chibuike C Udenigwe, and Rong He J. Agric. Food Chem., Just Accepted Manuscript • DOI: 10.1021/acs.jafc.7b05083 • Publication Date (Web): 16 Feb 2018 Downloaded from http://pubs.acs.org on February 16, 2018

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.

Journal of Agricultural and Food Chemistry 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 29

Journal of Agricultural and Food Chemistry

Polyelectrolyte complex nanoparticles from chitosan and acylated rapeseed cruciferin protein for curcumin delivery Fengzhang Wang1, Yijie Yang1, Xingrong Ju1, Chibuike C. Udenigwe2, Rong He1*

1

College of Food Science and Engineering/Collaborative Innovation Center for Modern Grain

Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China 2

School of Nutrition Sciences, Faculty of Health Sciences, University of Ottawa, 451 Smyth Road,

Ottawa, Ontario, K1H 8M5, Canada

*Corresponding authors: Email: [email protected] (R. He)

ACS Paragon Plus Environment


1

ABSTRACT: Curcumin is a polyphenol that exhibits several biological activities, but its low

2

aqueous solubility results in low bioavailability. To improve curcumin bioavailability, this study has

3

focused on developing polyelectrolyte complexation method to form layer-by-layer assembled

4

nanoparticles, for curcumin delivery, with positively charged chitosan (CS) and negatively charged

5

acylated cruciferin (ACRU), a rapeseed globulin. Nanoparticles (NPs) were prepared from ACRU

6

and CS (2:1) at pH 5.7. Three samples with weight of 5%, 10% and 15% of curcumin, respectively,

7

in ACRU/CS carrier were prepared. To verify the stability of the NPs, encapsulation efficiency and

8

size of the 5% Cur-ACRU/CS NPs were determined at intervals of five days in one month period.

9

Fourier transform infrared spectroscopy (FTIR), X-ray diffraction and differential scanning

10

calorimetry confirmed the electrostatic interaction and hydrogen bond formation between the carrier

11

and core. The result showed that hollow ACRU/CS nanocapsules (ACRU/CS NPs) and curcumin

12

loaded ACRU/CS nanoparticles (Cur-ACRU/CS NPs) were homogenized spherical with average

13

sizes of 200-450 nm and zeta potential of +15 mV. Encapsulation and loading efficiencies were 72%

14

and 5.4%, respectively. In vitro release study using simulated gastro (SGF) and intestinal fluids (SIF)

15

showed controlled release of curcumin in 6 h of exposure. Additionally, the Cur-ACRU/CS NPs are

16

nontoxic to cultured Caco-2 cells and the permeability assay indicated that Cur-ACRU/CS NPs had

17

improved permeability efficiency of free curcumin through the Caco-2 cell monolayer. The findings

18

suggest that ACRU/CS NPs can be used for encapsulation and delivery of curcumin in functional

19

foods.

20 21

KEYWORDS: Rapeseed protein; Curcumin; Chitosan; Nanoencapsulation; Polyelectrolyte

22

complexes


Page 2 of 29

Page 3 of 29


23

INTRODUCTION

24

Many attempts have been made to develop new delivery systems for bioactive compounds. Presently,

25

nanoparticles have been widely used in delivery systems and show great potential in medical,

26

biological and pharmaceutical applications1. Several mechanisms can be used to prepare

27

nanoparticles, such as ionic cross-linking, covalent cross-linking, polyelectrolyte complexation, and

28

self-assembly of hydrophobically modified polysaccharides among others2. Polyelectrolyte

29

complexes are formed from strong electrostatic interactions between oppositely charged polymers as

30

well as other forces such as hydrogen bonding and hydrophobic interactions. This method does not

31

involve the use of organic solvents and cross-linking agents, empowering it an ideal nanocarrier

32

preparation method due to its low cost and low energy requirements and effectiveness3.

33

Curcumin is a hydrophobic polyphenolic compound isolated from Curcuma longa that exhibits

34

strong antioxidant, anti-inflammatory, antimicrobial and anticancer activities4-6. Nevertheless, its low

35

aqueous solubility, chemical instability, poor oral bioavailability and rapid clearance limit its

36

application in therapeutics and the food industry7. A variety of nanoparticles has been studied as

37

potential vehicles for delivering curcumin through different routes in the body. In recent years, food

38

grade proteins, such as zein8, kafirin9, legumin and casein10 are popularly used for curcumin

39

nanoencapsulation. However, low loading efficiency and fast release of the encapsulated compound

40

are still observed. To address this challenge, acylated cruciferin and chitosan were used in this study

41

to encapsulate curcumin to improve its oral bioavailability.

42

Cruciferin, a natural storage protein derived from rapeseed, is an ideal material for delivery of

43

nutrients due to its well-balanced essential amino acids composition, good emulsifying and gelling

44

properties11, 12. Cruciferin is composed of six subunits with an isoelectric point (pI) of around 7.2 and

45

a molecular weight of 300 kDa. Although cruciferin is not completely soluble in water, its structure

46

can be modified (e.g. by succinic acid anhydride treatment) to improve its solubility. There is a

47

dearth of information on the use of rapeseed proteins in delivering bioactive compounds. In this



48

study, polyelectrolyte method was used for encapsulation and this involved static interaction between

49

positively charged chitosan and negatively charged cruciferin to form a shell to encapsulate

50

curcumin.

51

Several studies have utilized polysaccharides such as cyclodextrin13, starch14, cellulose15,

52

hyaluronic acid16 and calcium carbonate17 to produce nanoparticles. Chitosan, a positively charged

53

polyelectrolyte, has been widely used to encapsulate biomaterials destined for delivery because of its

54

unique chemical properties such as biodegradability, biocompatibility, low toxicity and mucosal

55

adhesion, which favor the absorption and bioavailability of the encapsulated materials18-20.

56

The objective of this study was to prepare hybrid nanoparticles by polyelectrolyte method using

57

chitosan and modified cruciferin as the shell and curcumin as the core, for enhancing the

58

bioavailability of curcumin. Formulations of both hollow nanoparticles and curcumin-loaded

59

nanoparticles were characterized in terms of particle size distribution, zeta potential, loading and

60

encapsulation efficiency, and morphology. The encapsulation process was monitored by

61

spectroscopy and calorimetry techniques to identify the driving forces in nanoparticle formation. In

62

addition, in vitro release study was conducted in simulated gastrointestinal conditions to evaluate the

63

controlled release of free curcumin from the ACRU/CS carrier. Caco-2 cells were also used to

64

evaluate cellular uptake, cytotoxicity and transport efficiency of the nanoparticles.

65

MATERIALS AND METHODS

66

Materials. Curcumin (85% purity) was purchased from DingBei Biological Company (Nanjing,

67

China). Chitosan (99% purity, with medium molecular weight) and succinic acid anhydride were

68

purchased from Sigma Aldrich (St. Louis, MO, USA). Rapeseed protein was extracted from Brassica

69

napus, which was a gift from Donghai Oil Industry (Nantong, China). Caco-2 cells were provided by

70

Food Technology Department at Nanjing Agricultural University, China. Dulbecco’s modified Eagle

71

medium (DMEM) and fetal bovine serum (FBS) were purchased from Life Technologies (Carlsbad,

72

CA, USA). Phosphate buffer (PBS, pH 7.2-7.4), Hank’s balanced salt solution (HBSS) and MTT


Page 4 of 29

Page 5 of 29


73

(3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetra-zolium bromide) were purchased from Solarbio

74

Science and Technology Co., Ltd. (Beijing, China).

75

Preparation of cruciferin. Cruciferin, a globular rapeseed protein, was extracted using the

76

previously reported method21 with some modifications. Briefly, an aqueous slurry of defatted

77

rapeseed meal (1: 10, w/v) was adjusted to pH 11 with 1 M NaOH, stirred for 4 h and centrifuged at

78

12,000 rpm for 20 min at 4°C. The supernatant was passed through an ultrafiltration membrane with

79

a molecular weight cut-off (MWCO) of 100 kDa using an ultrafiltration system (UFSC 40001, U.S.)

80

under constant nitrogen passage of 60 psi. Then the retentate (>100 kDa) and the permeate (

Polyelectrolyte Complex Nanoparticles from Chitosan and Acylated

Recommend Documents