Review
Nanoencapsulation of food ingredients using lipid based delivery systems

https://doi.org/10.1016/j.tifs.2011.08.003Get rights and content

Nanoencapsulation allows protection of the sensitive bioactive food ingredients from unfavorable environmental conditions, eradication of incompatibilities, solubilization, or masking of unpleasant taste or odor. This paper reviews the present state of the art of lipid based carriers including nanoemulsions, nanoliposomes, solid lipid nanoparticles (SLNs) and novel generation of encapsulation system namely nanostructure lipid carriers (NLCs) regarding their production method, physicochemical properties, functionalities, stabilization techniques, potential advantages and limitations and delivery mechanisms. In the last section, mathematical models for predication of bioactive release kinetics from lipid based nanocarriers, which can be applied for optimization of encapsulation systems, are presented and some future developments in the area of nanoencapsulation are discussed.

Introduction

Nanotechnology is defined as creation, utilization and manipulation of materials, devices or systems in the nanometer scale (smaller than 100 nm). In recent years nanotechnology has found innumerable applications in different food industries (Aguilera et al., 2008, Fathi and Mohebbi, 2010, Neethirajan and Jayas, 2010, Rizvi et al., 2010, Sanguansri and Augustin, 2006). Some potential applications of this technology in nanoencapsulation and delivery of bioactive components have been documented in pharmaceutics, as well as cosmetics and food sciences (Farokhzad and Langer, 2009, Liu et al., 2008, Müller et al., 2007, Sagalowicz et al., 2006, Shah et al., 2007, Shimoni, 2009). Delivery system is defined as one in which a bioactive material is entrapped in a carrier to control the rate of bioactive release. Nanocarriers can protect a bioactive component from unfavorable environmental conditions e.g. oxidation and pH and enzymes degradation (Fang and Bhandari, 2010, Ghosh et al., 2009, Zimet and Livney, 2009). Nanocarriers provide more surface area and have the potential to enhance solubility, improve bioavailability and ameliorate controlled release and targeting of the encapsulated food ingredients, in comparison to micro-size carriers (Mozafari, 2006a, Weiss et al., 2009).

Generally two controlled release mechanisms (Fig. 1) can be observed during delivery of a bioactive (Lakkis, 2007). (i) Delayed release, which is a mechanism by which the release of a bioactive substance is delayed from a bounded “lag time” up to a point when/where its release is preferred and is no longer obstructed. This mechanism could be used for flavor release in ready-meals, color release in beverages or protection of nutrition compounds in gastric condition and their release in the intestine. (ii) Sustained release, which is a mechanism engineered to keep constant concentration of a bioactive at its target site. This system can be employed for extending the release of the encapsulated material, including flavor or certain drugs such as insulin, in chewing gum. Many variables overshadow bioactive release of the encapsulated material. These include shape and dimensions of carrier, bioactive diffusivity and solubility in encapsulant and environmental media, erosion rate, polymorphism status of lipid based carriers, porosity and tortuosity, bioactive ratio between carrier and aqueous medium, encapsulation load (weight ratio of encapsulant to lipid) and loading efficiency (weight ratio entrapped to free encapsulant) and pH value of the medium (Barat et al., 2008, Briones and Sato, 2010, Jalsenjak, 1992, Sant et al., 2005, Siepmann et al., 2002, Yang and Washington, 2006, Zhang et al., 2003). Having a high encapsulation efficiency is always favorable, albeit encapsulation load more than 50% is not proper due to increase risk of bioactive leakage in case of more surface defect (Madene, Jacquot, Scher, & Desobry, 2006).

Typically, food applicable nanocarrier systems can be carbohydrate, protein or lipid based. Despite of different advantages of carbohydrate and protein based nanocapsules, they do not have potential of fully scale up due to requirement of applying different complicated chemical or heat treatments which cannot be completely controlled. On the other hand, lipid based nanocarriers have possibility of industrial production and bear advantage of more encapsulation efficiency and low toxicity. In this paper we will provide an overview of recent developments in different aspects (e.g. production methods, physicochemical properties, stabilization techniques, release mechanisms, advantages and disadvantages) of four famous lipid based carriers namely nanoemulsions, nanoliposomes, solid lipid nanoparticles (SLNs) and nanostructure lipid carriers (NLCs) (Table 1). In the last section of the paper, mathematical models for predication of bioactive release kinetics of lipid based nanocarriers are presented.

Section snippets

Nanoemulsions

Nanoemulsions (also known as miniemulsions or submicron emulsions) are nanoscale droplets of multiphase colloidal dispersions formed by dispersing of one liquid in another immiscible liquid by physical share-induced rupturing (Liu et al., 2006, Mason et al., 2006, Meleson et al., 2004, Russel et al., 1989). Different size ranges have been reported in the literature for nanoemulsions; e.g. less than 100 nm (Guo et al., 2007, Porras et al., 2008, Shakeel and Ramadan, 2010), 10–100 nm (

Modeling bioactive release of nanoscale delivery systems

Towards augmenting the controlled delivery systems, mathematical modeling of the release process plays an important role as it demonstrates the mechanism(s) of bioactive release, provides a scenario for the optimization of the carrier systems and avoids excessive experimentation. Generally, the bioactive release is governed by one or combination of three different mechanisms, i.e. (i) diffusion; (ii) erosion; and (iii) swelling. However, the two latter ones are more likely to occur in

Concluding and future remarks

Despite the strong upsurge in the investigations of nano-delivery systems and proven role of nanoencapsulation in enhancing bioavailability, solubility and protection of food ingredients, there is no comprehensive information on different aspects of lipid-based nanocarriers. In this paper we attempted to provide an overview of latter developments of four lipid based encapsulation systems namely nanoemulsions, liposomes, solid lipid nanoparticles and nanostructure lipid carriers. Recent studies

References (187)

  • A. Chonn et al.

    Recent advances in liposome technologies and their applications for systemic gene delivery

    Advanced Drug Delivery Reviews

    (1998)
  • J.S. Colas et al.

    Microscopical investigations of nisin-loaded nanoliposomes prepared by Mozafari method and their bacterial targeting

    Micron

    (2007)
  • L.M. Crowe et al.

    Prevention of fusion and leakage in freeze-dried liposomes by carbohydrates

    Biochimica et Biophysica Acta (BBA) - Biomembranes

    (1986)
  • L. Cruz et al.

    Diffusion and mathematical modeling of release profiles from nanocarriers

    International Journal of Pharmaceutics

    (2006)
  • J.-Y. Fang et al.

    Lipid nanoparticles as vehicles for topical psoralen delivery: Solid lipid nanoparticles (SLN) versus nanostructured lipid carriers (NLC)

    European Journal of Pharmaceutics and Biopharmaceutics

    (2008)
  • Z. Fang et al.

    Encapsulation of polyphenols - a review

    Trends in Food Science & Technology

    (2010)
  • C. Freitas et al.

    Spray-drying of solid lipid nanoparticles (SLN)

    European Journal of Pharmaceutics and Biopharmaceutics

    (1998)
  • A. Ghosh et al.

    Nanoencapsulation of quercetin enhances its dietary efficacy in combating arsenic-induced oxidative damage in liver and brain of rats

    Life Sciences

    (2009)
  • Z.S. Haidar et al.

    Protein release kinetics for coreeshell hybrid nanoparticles based on the layer-by-layer assembly of alginate and chitosan on liposomes

    Biomaterials

    (2008)
  • T. Hamouda et al.

    A novel surfactant nanoemulsion with a unique non-irritant topical antimicrobial activity against bacteria, enveloped viruses and fungi

    Microbiological Research

    (2001)
  • H. Hayashi et al.

    Temperature-controlled release property of phospholipid vesicles bearing a thermo-sensitive polymer

    Biochimica et Biophysica Acta (BBA) - Biomembranes

    (1996)
  • A. Heikal et al.

    The stabilisation of purified, reconstituted P-glycoprotein by freeze drying with disaccharides

    Cryobiology

    (2009)
  • T. Helgason et al.

    Effect of surfactant surface coverage on formation of solid lipid nanoparticles (SLN)

    Journal of Colloid and Interface Science

    (2009)
  • J.V.L. Henry et al.

    The influence of phospholipids and food proteins on the size and stability of model sub-micron emulsions

    Food Hydrocolloids

    (2010)
  • T. Higuchi

    Mechanism of sustained-action medication: theoretical analysis of rate of release of solid drugs dispersed in solid matrices

    Journal of Pharmaceutical Sciences

    (1963)
  • A. Huwiler et al.

    Physiology and pathophysiology of sphingolipid metabolism and signaling

    Biochimica ET Biophysica Acta

    (2000)
  • K. Iwanaga et al.

    Application of surface-coated liposomes for oral delivery of peptide: effect of coating the liposome’s surface on the GI transit of insulin

    Journal of Pharmaceutical Sciences

    (1999)
  • S.M. Jafari et al.

    Nano-particle encapsulation of fish oil by spray drying

    Food Research International

    (2008)
  • J. Jaiswal et al.

    Preparation of biodegradable cyclosporinenanoparticles by high-pressure emulsification-solvent evaporation process

    Journal of Controlled Release

    (2004)
  • J.-P. Jee et al.

    Stabilization of all-trans retinol by loading lipophilic antioxidants in solid lipid nanoparticles

    European Journal of Pharmaceutics and Biopharmaceutics

    (2006)
  • V. Jenning et al.

    Vitamin A-loaded solid lipid nanoparticles for topical use: drug release properties

    Journal of Controlled Release

    (2000)
  • S. Kentish et al.

    The use of ultrasonics for nanoemulsion preparation

    Innovative Food Science and Emerging Technologies

    (2008)
  • K. Khosravi-Darani et al.

    The role of high-resolution imaging in the evaluation of nanosystems for bioactive encapsulation and targeted nanotherapy

    Micron

    (2007)
  • U. Klinkesorn et al.

    Influence of chitosan on stability and lipase digestibility of lecithin-stabilized tuna oil-in-water emulsions

    Food Chemistry

    (2009)
  • K. Kono et al.

    Temperature-sensitive liposomes: liposomes bearing poly (N-isopropylacrylamide)

    Journal of Controlled Release

    (1994)
  • K. Kono et al.

    Thermosensitive polymer-modified liposomes that release contents around physiological temperature

    Biochimica et Biophysica Acta (BBA) - Biomembranes

    (1999)
  • S. Lee et al.

    Fabrication of protein-stabilized nanoemulsions using a combined homogenization and amphiphilic solvent dissolution/evaporation approach

    Food Hydrocolloids

    (2010)
  • T.S.H. Leong et al.

    Minimising oil droplet size using ultrasonic emulsification

    Ultrasonics Sonochemistry

    (2009)
  • H. Li et al.

    Polyethylene glycol-coated liposomes for oral delivery of recombinant human epidermal growth factor

    International Journal of Pharmaceutics

    (2003)
  • N. Li et al.

    Liposome coated with low molecular weight chitosan and its potential use in ocular drug delivery

    International Journal of Pharmaceutics

    (2009)
  • S.J. Lim et al.

    Formulation parameters determining the physicochemical characteristics of solid lipid nanoparticles loaded with all-trans retinoic acid

    International Journal of Pharmecutical

    (2002)
  • A. Lippacher et al.

    Liquid and semisolid SLN(TM) dispersions for topical application: rheological characterization

    European Journal of Pharmaceutics and Biopharmaceutics

    (2004)
  • A. Lippacher et al.

    Semisolid SLN(TM) dispersions for topical application: influence of formulation and production parameters on viscoelastic properties

    European Journal of Pharmaceutics and Biopharmaceutics

    (2002)
  • W. Liu et al.

    Formation and stability of paraffin oil-in-water nano-emulsions prepared by the emulsion inversion point method

    Journal of Colloid and Interface Science

    (2006)
  • Z. Liu et al.

    Polysaccharides-based nanoparticles as drug delivery systems

    Advanced Drug Delivery Reviews

    (2008)
  • Y.L. Lo et al.

    Liposomes and disaccharides as carriers in spray-dried powder formulations of superoxide dismutase

    Journal of Controlled Release

    (2004)
  • R.M. Mainardes et al.

    PLGA nanoparticles containing praziquantel: effect of formulation variables on size distribution

    International Journal of Pharmaceutics

    (2005)
  • T.J. Mason

    Industrial sonochemistry: potential and practicality

    Ultrasonics

    (1992)
  • G. Maulucci et al.

    Particle size distribution in DMPC vesicle solutions undergoing different sonication times

    Biophysical Journal

    (2005)
  • D.J. McClements et al.

    Structured emulsion-based delivery systems: controlling the digestion and release of lipophilic food components

    Advances in Colloid and Interface Science

    (2010)
  • Cited by (519)

    View all citing articles on Scopus
    View full text