Agriculture Reference
In-Depth Information
Liposomes have been made for drug delivery for many years and have been
primarily used in pharmaceuticals and cosmetics, but applications in agriculture
and food technology are also described. The use of liposomes in agriculture has
been mainly associated as model membranes of plant organelles, leading to
research in plant ageing, drying and freeze tolerance, and effects of toxins and
pesticides (Taylor et al.
2005
). However, the development of water-soluble lipo-
somes may extend the potential use of antifungal drugs or antibiotics developed for
other purposes for applications in agriculture. A new formulation embedding the
broad-spectrum, water-insoluble, macrolide polyene antibiotic amphotericin B
(AMB) in nanodisks composed of phospholipids and apolipoprotein A-I enhances
antibiotic solubility and confers protection against environmental damage. The
AMB-nanodisks were tested for efficacy against several phytopathogenic fungi
in vitro and on infected living plants of chickpea and wheat. The results confirm
that formulation of AMB increases its effectiveness against phytopathogenic fungi
in vitro and showed some effect against fusarium wilt in chickpea, suggesting the
possibility for its use on infected plants in the field (P´rez-de-Luque et al.
2011
). In
addition, applications in veterinary and animal science have been developed,
increasing the efficiency of drug delivery in farm animals (Kuzma
2010
). However,
the main use of liposomes is associated with the food industry, especially for
protection of substances such as enzymes, vitamins, and antimicrobials, until
their release for improving the food quality (Mozafari et al.
2008
; Malheiros
et al.
2010a
).
The antimicrobial peptide nisin, which is approved for food use in many
countries, has been incorporated in nanometric liposomes, showing effective anti-
microbial activity against important food pathogens (Malheiros et al.
2010a
). A
significant increase of the lag phases of
L. monocytogenes
and
E. coli
O157:H7 was
observed by encapsulation of nisin and EDTA into liposomes, resulting in bacteri-
ostatic inhibition of these pathogens for at least 48 h (Taylor et al.
2008
). The
addition of encapsulated nisin to fluid milk resulted in significant increase of the lag
phase of
L. monocytogenes
Scott A incubated at 5
Cor20
C (Schmidt et al.
2009
).
Likewise, the inhibition of
L. monocytogenes
was achieved in either whole or
skimmed fluid milk added with nanoencapsulated nisin and maintained at 7
Cor
30
C (Malheiros et al.
2010b
). The bacteriocin pediocin PA-1/AcH was also
recently formulated in liposomes, and the antimicrobial activity against several
strains of
Listeria
spp. was demonstrated (Mello et al.
2013
). Although reports in
real food systems are relatively scarce, these studies indicate that nanoparticles
containing antimicrobials can be effective to control foodborne pathogens.
6.3.3 Polymeric Nanoparticles
Polymers have become the major constituents of nanoparticles used for drug
delivery purposes. These nanoparticles can be formed by a polymeric membrane
that encloses a liquid core, referred as nanocapsules. The antimicrobials can be
