Toxicological Impacts: Nutrition and Nanotechnology. Bernadene Magnuson, Ph.D.

Transcription

1 Toxicological Impacts: Nutrition and Nanotechnology Bernadene Magnuson, Ph.D.

2 Uses and benefits Improved uptake of low bioavailability nutrients or bioactive food compounds Enhance uptake of nutrients in individuals with absorption disorders Alter hydrophobicity/lipophilicity of nutritional fortifications Improved stability and sensory qualities of fortified food

3 Key Points 1. Nutritional products claiming to use nanotechnology are available in the market. 2. Nanotechnology can be used to alter bioavailability of nutrients and bioactives. 3. The potential toxicity of nutrients can be affected by a change in particle size.

4 Examples of products A Nanotechnology Consumer Products Inventory Displaying records 1-10 of 64 for food Includes packaging, appliances, supplements June 20,

5 Nutralease Co-enzyme Q10 (Ubiquinon) Lutein Lycopene Phytosterol (sitosterol) Vitamin D Vitamin E patent pending Nano-sized Self-assembled Liquid Structures (NSSL) vehicles are expanded micelles (~30 nm); fortifying nano-vehicles ( FNVs).

6 Canola Active Nanocapsules in cooking oil to improve bioavailability of nutraceuticals, for example, plant sterols to reduce the body s absorption of cholesterol in the blood. Incorporates phytosterol-filled nanovesicles from Nutralease into canola oil On the market in Israel Shemen Industries Ltd

7 Aquanova, Germany Use nanotechnology to produce micelles to improve solubility of insoluble bioactives to change water/fat solubility of nutrients Vitamins A, C, D, E, K Coenzyme 10 β-carotene, isoflavones, α-lipoic acid, omega fatty acids

8

9 Nano-tea Nano-Green Tea Nano-Dark-Green Tea Nano-White Tea Nano-Black Tea Nano-Yellow Tea Nano-Dark Tea Nano-Selenium Rich White Tea Nano-Selenium Rich Dark Green Tea Nano-Selenium Rich Black Tea Nano-Selenium Rich Green Tea Nano-Selenium Rich Yellow Tea Nano-Selenium Rich Dark Tea

10 NanoGreens10 is formulated with patented "NanoSorb"ô which utilizes nanosized vesicles that spontaneously encapsulate nutraceuticals to maximize availability for absorption by the small intestine! NanoGreens Ingredient list Greens Blend (Proprietary) 2350 mg Barley Grass Juice Powder*, Spirulina*, Chlorella (Japanese soft shell) Phyto-Nutrient Blend (Proprietary) 325 mg Blueberry, Green Tea Extract, Grape Seed Extract, Cranberry, Raspberry, Tart Cherry, Pine Bark Extract, Broccoli, Tomato, Carrot, Spinach, Kale, Brussels Sprout, Bilberry, Elderberry,Pomegranate, Blackberry Isoquercitin/Rutin 50/ mg Raspberry Extract (20% Ellagic Acid) 50 mg Fruit & Vegetable Blend 900 mg Quercitin Ellagic acid Apple*, Carrot*, Mango*, Sweet Potato*, Lemon*, Parsley*, Peach*, Kale*, Broccoli*, Spinach*, Leek*, Beet*, Cranberry* (Quinic Acid 6%) Acerola Cherry Powder* (17.5% Ascorbic Acid) 175 mg Rice Bran Soluble* 2500 mg Aloe Vera Powder Extract* (100:1 freeze dried) 30 mg Green Tea, White Tea (decaffeinated, 50% Polyphenol) 100 mg Polygonum Cuspidatum (15% Resveratrol) 50 mg Oat Beta Glucan* 2200 mg Cinnamon Blend (Proprietary) 50 mg (Cinnamon Extract 8%, Cinnamon Bark Powder) Milk Thistle (20% Silymarin) 50 mg Marigold Extract (5% Lutein with Zeaxanthin) 50 mg Dunaliella Salina (Natural Carotenoids) 100 mg Enzymes (plant-based) 40 mg Alpha Amylase, Bromelain, Cellulase, Galactosidase, Glucoamylase, Hemicellulase, Lipase, Papain, Protease Lecithin (non GMO) 1925 mg Cabbage (Japanese, fermented) 30 mg Lycopene Extract-10% (from tomato) 25 mg Lemon Peel Powder* 25 mg Quinoa Sprout* 90 mg Artichoke Extract (5% Cynarin) 20 mg Atlantic Kelp Powder* (Laminara Digitata) 20 mg Natural flavors (plant-based), stevia, NanoSorb (phospholipids, lipid esters), citric acid.

11 General concerns over nanoscale versus microscale materials Higher exposure per unit mass Small size, large surface area, may result in increased ability to generate Reactive Oxygen Species (ROS) Routes of exposure may differ due to smaller size. E.g. olfactory transport, dermal penetration Different distribution to tissues by virtue of their different size or surface coating/chemistry. E.g. Inflammatory responses induced by fine and ultrafine TiO2 Novel property of nanoscale material may translate into a new mode of action. Nel et al., Science 2006

12 Factors affecting uptake and translocation of orally administered nanoparticles Diameter below 1µm, decreased diameter increased uptake Surface charge non-ionic uptake higher Shape and elasticity no clear shape effect, elasticity increases ability to traverse capillaries Physical and chemical stability Colloidal instability leads to aggregation, chemical stability affects biodegradability and release of encapsulated material Florence, Drug Disc Today 2005

13 Issues regarding nanoparticles for nutrient delivery Safety of the nanoparticle delivery system per se

14 One approach Delivery vehicle not absorbed - Nutralease, Aquanova

15 Toxicity evaluation of void nanoparticle Polymeric particles : NIPAA-M/VP/PEG-A N-isopropylacrylamide/ N-vinyl-2pyrrolidone/ Polyethylene glycol monoacrylate Cytotoxicity to various cancer cell lines Administration to mice twice a week for 3 weeks No change in body weight No gross pathology on necropsy J. Nanobiotechnology, 2007

16 Issues regarding nanoparticles for nutrient delivery Safety of the nanoparticles per se Change in toxicity of nutrient/bioactives due to increased uptake or altered distribution in body Nutrients with known toxicities Compounds that have low bioavailability Impact on nutritional labeling? how calculate %DV if change bioavailability?

17 Bioavailability of nano-nutrients Water-soluble vitamin E (Aquanova) Back et al., 2007 Ferric phosphate nanoparticles Rohner et al., 2007 Vitamin E (PEG encapsulated) nanospheres Shea et al., 2005 Selenium - Zhang et al., 2001 Copper - Chen et al., 2006 Zinc - Wang et al., 2006

18 Nanoparticles in the intestine

19 Water-soluble α-tocopherol Bioavailability of water-soluble α-tocopherol (100 IU) was ~50% greater than bioavailability of a commercial fat-soluble α-tocopherol (100 IU) preparation in 14 human subjects given a single oral dose. Back et al., Eur J. Nutr. 2007

20 Bioavailability of ferric phosphate Background nanoparticles in rats Highly bioavailable water-soluble FeSO 4 supplements cause adverse organoleptic changes in foods Low solubility Fe compounds, more stable in foods, less organoleptic change, but poor bioavailability Objective: improve bioavailability of FePO 4 by decreasing particle size to nm Rohner et al., 2007

21 Synthesis of FePO 4 nanoparticles Flame spray pyrolysis used to produce particles varying in diameter and specific surface area A. Large 64.2 nm diam, 32.6 m 2 /g SSA B. Medium 30.5 nm diam, 68.6 m 2 /g SSA C. Small 10.7 nm diam, m 2 /g SSA

22 In vitro solubility test of the 3 FePO4 compounds and FeSO4 at ph 1 Copyright 2007 American Society for Nutrition

23 Dose-response curves: Hb repletion assay in Fe-depleted rats consuming a Fe-def diet or the Fe-def diet fortified with FeSO4, FePO4 small, FePO4 medium, or FePO4 large particles for 15 days

24 Toxicity of FePO 4 nanoparticles Evaluated histology liver, spleen, kidney, stomach, duodenum, jejunum, ileum, colon, pancreas, lymphatic tissue and sternum Special stains for Fe deposits TEM for damage to duodenum mucosa Plasma TBARS for reactive oxygen No evidence of potential toxicity in Fedepleted rats fed FePO 4 nanoparticles for 15 days

25 Summary of findings Nanotechnology can be used to alter form of nutrients such that solubility properties are altered, but physiological properties retained Nanotechnology can improve bioavailability of poorly absorbed nutrients May be beneficial in cases of malabsorption and for improved fortification

26 Background Acute toxicity of copper microand nanoparticles Copper is essential micronutrient Copper toxicity results in hemolysis and liver and kidney damage Objective Compare acute toxicity of oral administration of copper micro- and nano-particles Chen et al., 2006 Tox Lett

27 Test materials Nano-copper average size 23.5 nm (distribution not given); SSA 2.95 x 10 5 cm 2 /g Particle number 1.7 x10 10 /µg Micro-copper average size 17µm (distribution not given); SSA 3.99 x 10 2 cm 2 /g Particle number 44/µg Mice - ICR strain, both sexes, age 8 wks, - single oral gavage, tissues collected 48 h after dosing Chen et al., 2006 Tox Lett

28 Results Group MicroCu 700 mg/kg NanoCu 700 mg/kg Control Vehicle only BUN Cr ALP LD50 (mmol/l) (µmol/l) (IU) (mg/kg) > * 66.0* 186* NA Renal function tests: BUN= Blood urea nitrogen, Cr= Creatinine, Liver damage: ALP=alkaline phosphatase * P<0.05 vs control Chen et al., 2006 Tox Lett

29 Pathological changes in kidney Chen et al., 2006 Tox Lett

30 Pathological changes in kidney Control (a); lower dose group N1 (b); medium dose group N4 (c) and higher dose group N7 (d). A: renal glomerulus and B: Bowman's capsule. Magnification = 100X

31 Pathological changes in the spleen Chen et al., 2006 Tox Lett

32 Pathological changes in the spleen Control (a); groups N1 (b); N4 (c) and N7 (d). A: splenic unit and B: lymphocytes. Magnification = 40X

33 Summary Data do not imply toxicity due to nanoparticle per se, no evidence of uptake of particle The difference in size of Cu particles altered biological effects, likely due to release of Cu ions Comparison of toxicity/biological activity based on SSA (700 fold diff) rather than mg/kg may be more appropriate Demonstrates that cannot assume that non-toxic compounds will remain non-toxic If there is a change in physical properties need to determine if changes biological effects.

34 Conclusions 1. Nutritional products claiming to use nanotechnology are available in the market. 2. Nanotechnology can be used to alter bioavailability of nutrients and bioactives. 3. The potential toxicity of nutrients can be affected by a change in bioavailability and/or particle size.

35 Key References Back EI et al., Eur J Nutr 45(1):1-6 Bisht S et al., J Nanobiotech 17(5):3 Chen Z et al., 2006 Tox Lett 163: Florence AT Drug Disc Today 2:75 Nel A et al., Science 311: Rohner F et al., J Nutr 137: Shea TB et al., J Alzh Dis 7: