ABSTRACT
The ef‰cacy of orally administered vaccines is generally low due to factors such as degradation of the antigen in the gastrointestinal (GI) tract and low uptake by gut-associated lymphoid tissue (GALT). Peyer’s patches (PPs) are the main target for oral vaccines, which are present in the lower ileum. The intestinal epithelium overlying PPs is specialized to allow the transport of pathogens into the lymphoid tissue. This sampling function is carried out by M-cells [1]. Association of the vaccine with microparticulate drug carrier systems may prevent its degradation in the stomach and the gut and may stimulate M-cells
3.3.2 Antimicrobial Chitosan Derivatives ................................................................... 140 3.3.2.1 Preparation of N-[1-hydroxy-3-(trimethylammonium)propyl]
Chitosan Chloride ................................................................................... 140 3.3.2.2 Antibacterial Activities of HTCC .......................................................... 140
3.3.3 Mechanism of Inhibition ...................................................................................... 141 3.3.3.1 Antibacterium Mechanism of Chitosan and HTCC .......................... 141 3.3.3.2 AFM Characterization ............................................................................ 142 3.3.3.3 Antibacterium Activity of the Schiff Base of Chitosan and
Metallic Ion-Loaded Chitosan Nanoparticles ..................................... 142 3.3.4 Conclusions ............................................................................................................. 143
References ..................................................................................................................................... 143 3.4 Pharmacological Activity ................................................................................................. 144
3.4.1 Antiin©ammatory Activity .................................................................................. 144 3.4.1.1 Cytokine and Chemical Substances Correlated with
In©ammatory Activity ........................................................................... 144 3.4.1.2 Characterization ...................................................................................... 145 3.4.1.3 Function of Chitosan in Antiin©ammatory Activity ......................... 145 3.4.1.4 Antiin©ammatory Activity of COSs .................................................... 146 3.4.1.5 Sustained Release Matrix of Chitosan Microspheres ........................ 146
3.4.2 Antiulcer.................................................................................................................. 149 3.4.2.1 Antiulcer Function of Chitosan ............................................................ 149 3.4.2.2 Promoting Ulcer Healing of Chitosan ................................................. 149 3.4.2.3 Accelerating Pressure Ulcer Cure of Growth Factor-Loaded Chitosan ......................................................................... 150
3.4.3 Fat and Hypocholesteremic Lowering ................................................................ 152 3.4.3.1 Function of Chitosan in Fat and Hypocholesteremic Lowering ...... 152 3.4.3.2 Characterization ...................................................................................... 154
3.4.4 Antitumor ............................................................................................................... 156 3.4.4.1 Antitumor Activity of an LMWC ......................................................... 156 3.4.4.2 Antitumor Activity of Chitosan Nanoparticles .................................. 158 3.4.4.3 Chitosan Colloidal Drug Carrier Systems for Antitumor Activity .... 159 3.4.4.4 Self-Assembly Chitosan Derivatives for Antitumor Activity ........... 162 3.4.4.5 Chitosan Hydrogels for Antitumors .................................................... 169
3.5 Conclusions ......................................................................................................................... 172 References ..................................................................................................................................... 172
to transport the vaccine to the dome of PPs [2-7]. After transport of the microparticles to the dome of PPs, the microparticles are degraded and the vaccine is released into the lymphoid tissue. Following stimulation by an antigen in PPs and its presentation to B-and T-cells, the antigen induces B-and T-cell proliferation and these cells subsequently leave PPs via efferent lymphatics and reach the systemic circulation through the thoracic duct. The uptake ef‰ciency by PPs is mainly dependent on the size of microparticles: particles larger than 10 μm are not internalized by M-cells [8].
