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Natural polysaccharides and their derivatives represent a group
of polymers widely used in pharmaceuticals and biomedicine for
the controlled release of drugs. Polysaccharides have several advantages over synthetic biopolymers to be used as a raw material for
the synthesis of new drug delivery systems. These materials are
nontoxic, and have good biocompatibility and low production
cost. Furthermore, polysaccharides are used for nanoparticle coating and are attractive candidates for biomedical applications
because of their biocompatibility and biodegradability. In addition,
the nanoparticles coated with polysaccharides are not recognized
by the phagocytic system. Since polysaccharides are hydrophilic
polymers, they induce system stability in the bloodstream and they
can lengthen the life span in the body and therefore increase the
absorption of encapsulated drugs. Thus, a combined use of polysaccharides with synthetic water-soluble polymers leads to the production of materials with improved biochemical and mechanical
properties [6–9].
With about 10
11
tons of cellulose growing and disappearing
annually, cellulose is the most common organic polymer in earth, a
poly-dispersed linear homopolymer consisting of region- and
enantioselective β-1,4 glycosidic-linked D-glucose units. In our
work, we use two derivatives of cellulose: cellulose succinate (CS)
and hydroxypropyl cellulose (HPC). CS is a pH-sensitive polymer
that is synthesized in solid phase at 398 K, without the use of solvents, only by using the melting point of succinic anhydride [10,
11]. HPC is a nonionic biodegradable polysaccharide, derivative of
cellulose which is a thermosensitive polymer, with a low critical
solution temperature in water (LCST) observed at 41 °C [12].
Chitosan is compatible with the biological tissues and does not
cause allergic reactions. It is biodegradable as it is cleaved by
enzymes in harmless products (amino sugar) which are completely
absorbed by the human body without causing side effects [13].
Chitosan possesses pharmacological properties such as hypocholesterolemic action, enhances healing of wounds, helps in the treatment of stomach ulcer, and has antimicrobial action [14, 15].
In the last years, searching the literature it can be realized that
there is an increase of publications related to drug delivery systems
based on polysaccharides. However, only few of the publications
are focusing on systems based on cellulose. In addition these publications do not focus particularly on pharmaceutical formulations
for specific diseases with in vitro and/or in vivo applications.
2 Materials
1. Polysaccharides: Powdered cellulose, MW = 78,000–
98,000 g/mol, was purchased from Riedel de Haen Ag Seelze—
Hannover. The medium molecular weight chitosan,
Aikaterini-Foteini Metaxa et al.
Natural polysaccharides and their derivatives represent a group
of polymers widely used in pharmaceuticals and biomedicine for
the controlled release of drugs. Polysaccharides have several advantages over synthetic biopolymers to be used as a raw material for
the synthesis of new drug delivery systems. These materials are
nontoxic, and have good biocompatibility and low production
cost. Furthermore, polysaccharides are used for nanoparticle coating and are attractive candidates for biomedical applications
because of their biocompatibility and biodegradability. In addition,
the nanoparticles coated with polysaccharides are not recognized
by the phagocytic system. Since polysaccharides are hydrophilic
polymers, they induce system stability in the bloodstream and they
can lengthen the life span in the body and therefore increase the
absorption of encapsulated drugs. Thus, a combined use of polysaccharides with synthetic water-soluble polymers leads to the production of materials with improved biochemical and mechanical
properties [6–9].
With about 10
11
tons of cellulose growing and disappearing
annually, cellulose is the most common organic polymer in earth, a
poly-dispersed linear homopolymer consisting of region- and
enantioselective β-1,4 glycosidic-linked D-glucose units. In our
work, we use two derivatives of cellulose: cellulose succinate (CS)
and hydroxypropyl cellulose (HPC). CS is a pH-sensitive polymer
that is synthesized in solid phase at 398 K, without the use of solvents, only by using the melting point of succinic anhydride [10,
11]. HPC is a nonionic biodegradable polysaccharide, derivative of
cellulose which is a thermosensitive polymer, with a low critical
solution temperature in water (LCST) observed at 41 °C [12].
Chitosan is compatible with the biological tissues and does not
cause allergic reactions. It is biodegradable as it is cleaved by
enzymes in harmless products (amino sugar) which are completely
absorbed by the human body without causing side effects [13].
Chitosan possesses pharmacological properties such as hypocholesterolemic action, enhances healing of wounds, helps in the treatment of stomach ulcer, and has antimicrobial action [14, 15].
In the last years, searching the literature it can be realized that
there is an increase of publications related to drug delivery systems
based on polysaccharides. However, only few of the publications
are focusing on systems based on cellulose. In addition these publications do not focus particularly on pharmaceutical formulations
for specific diseases with in vitro and/or in vivo applications.
2 Materials
1. Polysaccharides: Powdered cellulose, MW = 78,000–
98,000 g/mol, was purchased from Riedel de Haen Ag Seelze—
Hannover. The medium molecular weight chitosan,
Aikaterini-Foteini Metaxa et al.