injectable devices for gadolinium neutron capture therapy. The accumulation of
drug-loaded chitosan nanoparticles in tumour cells (L929 fibroblast cultured cells
as model) was 100–200 times higher in comparison to dimeglumine gadopenteate
aqueous solution (a magnetic resonance contrast agent). These findings indicated
the higher affinity of chitosan nanoparticles to tumour cells, thus contributing to the
long retention of gadolinium in tumour tissue and leading to suppression of tumour
growth in in vivo studies. The nanoparticles have recently been regarded as
promising carriers in breaching the epithelial and enzymatic barriers to enhance
the bioavailability of biomolecules. Surface-modified triglyceride nanoparticles,
using chitosan for salmon calcitonin delivery, have been developed and showed that
chitosan could be formed around the triglyceride nanoparticles by simple incubation of the lipid cores in chitosan solution, due to the high affinity of chitosan for the
lipid core, to provide a continuous and slow release of the associated peptide.
Recently, chitosan nanoparticles have been coated to enhance their stability and
to prevent immediate desorption in body fluids, including gastrointestinal fluids.
Sodium alginate was used as a coating material. In vitro release studies showed that
the presence of an alginate layer around the nanoparticles was able to prevent a
burst release of loaded model antigen and to improve the stability of the
nanoparticles in simulated gastrointestinal fluid. Liposomes have been coated by
chitosans to enhance their stability for oral administration of peptide drugs. It was
found that the chitosan-coated liposomes are more penetrative into the intestinal
mucosa and have higher retentive properties than non-coated liposomes.
The emergence of bioactive food compounds (neutraceuticals) with health
benefits provides an excellent opportunity to improve public health. The
incorporation of bioactive compounds, such as peptides and vitamins, into food
systems holds much promise in the development of innovative functional foods that
may have physiological benefits or reduce the risk of diseases. Compared to
pharmaceutical applications, little work has been done on the encapsulation
properties of chitosan nanoparticles for the oral administration of neutraceuticals
in healthy food. More recently, chitosan has been identified as a versatile biopolymer for a broad range of health and food applications because of its safety and nontoxicity in human beings. Because chitosan matrix is not stable at very low pH,
modifications to the chitosan micro- or nanoparticles might be able to protect them.
6.4 Applications of Alginate Nanoparticles
6.4.1 Alginate Nanoparticles as Antituberculosis Drug Carriers
An alginate-based nanoparticulate delivery system was developed for frontline
antituberculosis drugs (rifampicin, isoniazid, pyrazinamide and ethambutol). Alginate nanoparticles were prepared by controlled cation-induced gelification and
administered orally to mice. The drug levels were analysed by high performance
liquid chromatography (HPLC) in plasma and tissues. The therapeutic efficacy was
Biopolymeric Micro- and Nanoparticles: Preparation, Characterization and. . .
291
drug-loaded chitosan nanoparticles in tumour cells (L929 fibroblast cultured cells
as model) was 100–200 times higher in comparison to dimeglumine gadopenteate
aqueous solution (a magnetic resonance contrast agent). These findings indicated
the higher affinity of chitosan nanoparticles to tumour cells, thus contributing to the
long retention of gadolinium in tumour tissue and leading to suppression of tumour
growth in in vivo studies. The nanoparticles have recently been regarded as
promising carriers in breaching the epithelial and enzymatic barriers to enhance
the bioavailability of biomolecules. Surface-modified triglyceride nanoparticles,
using chitosan for salmon calcitonin delivery, have been developed and showed that
chitosan could be formed around the triglyceride nanoparticles by simple incubation of the lipid cores in chitosan solution, due to the high affinity of chitosan for the
lipid core, to provide a continuous and slow release of the associated peptide.
Recently, chitosan nanoparticles have been coated to enhance their stability and
to prevent immediate desorption in body fluids, including gastrointestinal fluids.
Sodium alginate was used as a coating material. In vitro release studies showed that
the presence of an alginate layer around the nanoparticles was able to prevent a
burst release of loaded model antigen and to improve the stability of the
nanoparticles in simulated gastrointestinal fluid. Liposomes have been coated by
chitosans to enhance their stability for oral administration of peptide drugs. It was
found that the chitosan-coated liposomes are more penetrative into the intestinal
mucosa and have higher retentive properties than non-coated liposomes.
The emergence of bioactive food compounds (neutraceuticals) with health
benefits provides an excellent opportunity to improve public health. The
incorporation of bioactive compounds, such as peptides and vitamins, into food
systems holds much promise in the development of innovative functional foods that
may have physiological benefits or reduce the risk of diseases. Compared to
pharmaceutical applications, little work has been done on the encapsulation
properties of chitosan nanoparticles for the oral administration of neutraceuticals
in healthy food. More recently, chitosan has been identified as a versatile biopolymer for a broad range of health and food applications because of its safety and nontoxicity in human beings. Because chitosan matrix is not stable at very low pH,
modifications to the chitosan micro- or nanoparticles might be able to protect them.
6.4 Applications of Alginate Nanoparticles
6.4.1 Alginate Nanoparticles as Antituberculosis Drug Carriers
An alginate-based nanoparticulate delivery system was developed for frontline
antituberculosis drugs (rifampicin, isoniazid, pyrazinamide and ethambutol). Alginate nanoparticles were prepared by controlled cation-induced gelification and
administered orally to mice. The drug levels were analysed by high performance
liquid chromatography (HPLC) in plasma and tissues. The therapeutic efficacy was
Biopolymeric Micro- and Nanoparticles: Preparation, Characterization and. . .
291