Glycated chitosan as a new non-toxic immunological stimulant.
Chitosan is capable of stimulating immune responses. However, because chitosan is not water soluble, it has limited biological applications. By attaching galactose molecules to the chitosan molecules, a new water-soluble compound, glycated chitosan (GC), was synthesized. GC was designed for immune stimulations in combination with phototherapies in the treatment of metastatic tumors. To investigate the possible toxicity of GC, cultures of normal and tumor cells were incubated with GC of different concentrations and the cell viabilities were determined. For in vivo studies, GC solution was fed or injected to animals and its toxicity was determined through observations of animals and histological examinations of vital organs. No toxic effects of GC were observed in cultured cells or in animal studies. In addition, the immunological effect of GC was investigated through its stimulation of TNFalpha secretion by macrophages in vitro. In vivo studies showed enhancement of the survival of laser immunotherapy-treated rats bearing metastatic mammary tumors. Our in vitro and in vivo results indicated that GC was a strong immunological stimulant. Its non-toxic nature and immunological activity make GC a potential immunoadjuvant for treatment of metastatic tumors.
Song
Sheng
S
MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, South China Normal University, Guangzhou, China.
Zhou
Feifan
F
Nordquist
Robert E
RE
Carubelli
Raoul
R
Liu
Hong
H
Chen
Wei R
WR
D000276:Adjuvants, Immunologic / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D048271:Chitosan / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology*; D005260:Female; D005690:Galactose / Q000737:chemistry; D007208:Indocyanine Green / Q000494:pharmacology; D053685:Laser Therapy; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D008325:Mammary Neoplasms, Experimental / Q000628:therapy; D051379:Mice; D010789:Phototherapy; D051381:Rats; D011920:Rats, Inbred WF; D012995:Solubility; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D000276:Adjuvants, Immunologic; D014409:Tumor Necrosis Factor-alpha; C121252:glycated chitosan; D048271:Chitosan; D007208:Indocyanine Green; D005690:Galactose