Zein Nanoparticles Uptake by Hydroponically Grown Soybean Plants

Nov 17, 2017 - Environmental Science & Technology. Masters-Waage, Morris, Lloyd, Shaw, Mosselmans, Boothman, Bots, Rizoulis, Livens, and Law. 2017 51 ...
2 downloads 14 Views 1MB Size
Subscriber access provided by READING UNIV

Article

Zein nanoparticles uptake by hydroponically grown soybean plants Kurt Ristroph, Carlos E Astete, Ede Bodoki, and Cristina M. Sabliov Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.7b03923 • Publication Date (Web): 17 Nov 2017 Downloaded from http://pubs.acs.org on November 18, 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.

Environmental Science & Technology 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 26

Environmental Science & Technology



ACS Paragon Plus Environment

Environmental Science & Technology

1

Zein nanoparticles uptake by hydroponically

2

grown soybean plants

3

Kurt D. Ristroph, Carlos E. Astete, Ede Bodoki, and Cristina M. Sabliov*

4

141 E. B. Doran Bldg, Department of Biological and Agricultural Engineering

5

Louisiana State University and LSU Agricultural Center

6

Baton Rouge, LA 70803

7 8

Email: [email protected]

9

KEYWORDS Polymeric nanoparticles, nanodelivery systems, zein, nanoparticle plant interaction, nanoparticle

Page 2 of 26

10

uptake kinetics

11

ABSTRACT: In the interest of developing and characterizing a polymeric nanoparticle pesticide

12

delivery vehicle to soybeans, zein nanoparticle (ZNP) uptake by the roots and biodistribution to

13

the leaves of soybean plants was measured. Zein was tagged with fluorescein isothiocyanate

14

(FITC) and made into nanoparticles (135±3 nm diameter. 0.202±0.034 PDI and 81±4 mV zeta-

15

potential at pH 6) using an emulsion-diffusion method. After ten days of hydroponic exposure,

16

association between particles and roots of plants was found to vary based on bulk nanoparticle

17

concentration. While 0.37 mg NP/mg dry weight were detected in roots immersed in 0.88 mg

18

NP/ml nanoparticle suspension, 0.58 mg NP/mg dry weight associated with roots immersed in a

19

high dose nanoparticle suspension of 1.75 mg NP/ml at 10 days. Nanoparticle root uptake

20

followed second order kinetics. A small amount of increased fluorescence was detected in the 1

ACS Paragon Plus Environment

Page 3 of 26

Environmental Science & Technology

21

hydroponically exposed plant’s leaves, suggesting that either small amounts of particles or other

22

fluorescent contaminants of zein were up taken by the roots and bio-distributed within the plant.

23

To the authors’ knowledge, this is the first study in which the uptake and time-dependent

24

association between polymeric nanoparticles and soybeans are quantified.

25 26

1. INTRODUCTION

27

In general, concerns over fate and impact of engineered nanoparticles (ENPs) made of

28

biodegradable chemical components such as zein, a corn protein, are significantly lower than

29

concerns over the use of inorganic metallic and metal oxide ENPs, which are often perceived as

30

potentially toxic.1 It is therefore not surprising that most reports investigating ENP impact on

31

plants as measured by germination, root elongation, and growth have focused on inorganic

32

nanoparticles. Studies of inorganic NPs environmental fate have provided insights on particle

33

accumulation in plants and soil, crucial for further use of these materials in agriculture. What is

34

known at this point is that plants can uptake ENPs through roots and leaves, but the uptake

35

mechanisms are poorly understood, even for inorganic ENPs.2 It has been proposed that ENPs

36

can penetrate the root epidermis and endodermis to access the xylem vessel and further

37

translocate to the aerial parts of the plant. The leaves can internalize ENPs through the leaf

38

stoma, which allows ENPs to reach the vascular system of the plant, with subsequent transport to

39

other tissues through the phloem.3-6

40

The data available for inorganic nanoparticles suggests that ENPs size, surface charge, functional

41

groups, type of plant, stage of plant growth, and exposure duration can all affect the amount of

42

ENPs internalized by plants;7-12 such findings are expected to hold true for organic nanoparticles 2

ACS Paragon Plus Environment

Environmental Science & Technology

Page 4 of 26

43

as well. The literature is diverse, and comparisons between studies are difficult given the

44

multitude of plants, conditions, and types of particles tested. A few trends can be identified for

45

inorganic nanoparticles. 1. ENP-plant interaction is very much a function of plant type. For

46

example, translocation of gold NPs was higher in rice and ryegrass compared to pumpkin and

47

radish.13 The internalization of 38 nm CeO2 NPs by maize was not significant,14 while 37 nm

48

Fe3O4 NPs, a similar primary particle size, were transported through pumpkin plants15 2. Size of

49

the ENPs plays an important role. Nanoparticles of sizes ranging from very small (