194
to the presence of nitrogen, cationicity, capacity to form polyelectrolyte complexes,
pH sensitivity, bioadhesive ability, solubility, absorbability, controllable biodegradability and mucoadhesive properties consequently allowing the polymer to become
water soluble after formation of carboxylate salts such as formate, acetate, lactate,
malate, citrate, glyoxylate, pyruvate, glycolate and ascorbate. All the above properties satisfy its need for use in sustained and controlled release including non- viral
vector for DNA gene and drug delivery. Native chitosan was replaced by some
chemical and biological modifications to enhance susceptibility to degradation by
nucleases of their cargo, improve cellular membrane permeability, solubility at
physiological pH and consequently increasing colloidal stability, specificity and
enabling formation of polyelectrolte complexes in gene delivery. Chemical modifications have been a strong tool to control interaction of chitosan with drugs for
enhanced load capability, upgrade bulk properties and to outfitter release profile of
nanoparticles. The esterification degree, acetyl-glucosamine, source and isolation
technique determine the composition and molar mass. Chitosan is insoluble at
higher pH and soluble at easily acidic pH. It has been used as an antioxidant, antimicrobial agent in various formulation and for target delivery of bioactives. This
positively charged gum has miscellaneous biotic activities e.g. antitumor activity,
immune enhancing effect, antibacterial, antifungal properties and used for delivery
of anticancer drugs, antibacterial drugs, antifungal drugs, anti-inflammatory drugs,
protein/peptides as well as for DNA/gene delivery. Chitosan capsules are not very
often used as they do not increase the viability of probiotic cells but chitosan is
mostly used as a coating or a shell. Various modification techniques (physical and
chemical) or a combination of chitosan with other hydrocolloids have been employed
to extend its biopolymer functional properties. The covalent crosslinking has been
widely used for the preparation of chitosan nanoparticles from early times. The
intermolecular crosslinking of chitosan nanoparticles was done by the use of water
soluble condensation agents of carbodiimide, natural dicarboxylic acid and tricarboxylic acids (Succinic acid, mailic acid, tartaric acid and citric acid). In this case,
production of chitosan nanoparticles was due to reaction between carboxylic group
of natural acids and amino groups of chitosan. The nanoparticle produced by reaction between carboxylic group of natural acids and pendant amino groups of chitosan group were stable in aqueous media at low pH, neutral and mild alkaline
conditions. The toxicity of glutraaldehyde on cell viability, limits its use as a crosslinking agent in the field of drug delivery. Tripolyphosphate (TPP) has been widely
used as polyanion crosslinker in various studies and was first used for synthesis of
chitosan nanoparticles. The combination of chitosan and tripolyphosphate (TPP)
form a gel by ionic interaction between positively charged amino groups of chitosan
and negatively charged counter ions of TPP and has widely been used for targeted
and controlled release of bioactives and drugs. Chitosan and its derivatives have
been widely used as ion removal, fiber forming, in cosmetics, for gene and drug
delivery. The production of nanoparticle chitosan reveals biological effects like
higher antitumor activity and is because of membrane disruption and apoptosis
inducing activity for cancer cells.
P. Chatur et al.
to the presence of nitrogen, cationicity, capacity to form polyelectrolyte complexes,
pH sensitivity, bioadhesive ability, solubility, absorbability, controllable biodegradability and mucoadhesive properties consequently allowing the polymer to become
water soluble after formation of carboxylate salts such as formate, acetate, lactate,
malate, citrate, glyoxylate, pyruvate, glycolate and ascorbate. All the above properties satisfy its need for use in sustained and controlled release including non- viral
vector for DNA gene and drug delivery. Native chitosan was replaced by some
chemical and biological modifications to enhance susceptibility to degradation by
nucleases of their cargo, improve cellular membrane permeability, solubility at
physiological pH and consequently increasing colloidal stability, specificity and
enabling formation of polyelectrolte complexes in gene delivery. Chemical modifications have been a strong tool to control interaction of chitosan with drugs for
enhanced load capability, upgrade bulk properties and to outfitter release profile of
nanoparticles. The esterification degree, acetyl-glucosamine, source and isolation
technique determine the composition and molar mass. Chitosan is insoluble at
higher pH and soluble at easily acidic pH. It has been used as an antioxidant, antimicrobial agent in various formulation and for target delivery of bioactives. This
positively charged gum has miscellaneous biotic activities e.g. antitumor activity,
immune enhancing effect, antibacterial, antifungal properties and used for delivery
of anticancer drugs, antibacterial drugs, antifungal drugs, anti-inflammatory drugs,
protein/peptides as well as for DNA/gene delivery. Chitosan capsules are not very
often used as they do not increase the viability of probiotic cells but chitosan is
mostly used as a coating or a shell. Various modification techniques (physical and
chemical) or a combination of chitosan with other hydrocolloids have been employed
to extend its biopolymer functional properties. The covalent crosslinking has been
widely used for the preparation of chitosan nanoparticles from early times. The
intermolecular crosslinking of chitosan nanoparticles was done by the use of water
soluble condensation agents of carbodiimide, natural dicarboxylic acid and tricarboxylic acids (Succinic acid, mailic acid, tartaric acid and citric acid). In this case,
production of chitosan nanoparticles was due to reaction between carboxylic group
of natural acids and amino groups of chitosan. The nanoparticle produced by reaction between carboxylic group of natural acids and pendant amino groups of chitosan group were stable in aqueous media at low pH, neutral and mild alkaline
conditions. The toxicity of glutraaldehyde on cell viability, limits its use as a crosslinking agent in the field of drug delivery. Tripolyphosphate (TPP) has been widely
used as polyanion crosslinker in various studies and was first used for synthesis of
chitosan nanoparticles. The combination of chitosan and tripolyphosphate (TPP)
form a gel by ionic interaction between positively charged amino groups of chitosan
and negatively charged counter ions of TPP and has widely been used for targeted
and controlled release of bioactives and drugs. Chitosan and its derivatives have
been widely used as ion removal, fiber forming, in cosmetics, for gene and drug
delivery. The production of nanoparticle chitosan reveals biological effects like
higher antitumor activity and is because of membrane disruption and apoptosis
inducing activity for cancer cells.
P. Chatur et al.