Practical synthesis and characterization of mannose-modified chitosan

Area of Science:

• Biomaterials Science
• Organic Chemistry
• Polymer Chemistry

Background:

• Chitosan is a versatile biopolymer with numerous applications.
• Modifying chitosan enhances its properties for specific uses.
• Mannose conjugation can improve chitosan's biological interactions.

Purpose of the Study:

• To develop a practical laboratory synthesis for mannose-modified chitosan (Man-chitosan).
• To characterize the synthesized Man-chitosan and assess its properties.
• To evaluate the cytotoxicity of Man-chitosan for potential biomedical applications.

Main Methods:

• Reductive amination reaction between chitosan and mannose.
• Characterization using (1)H NMR, ESI-MS, FT-IR, and TGA.
• Elemental analysis for degree of substitution determination.
• MTT assay for cytotoxicity assessment against HepG-2 and SMMC-7721 cells.

Main Results:

• Successful synthesis of Man-chitosan with a yield of 47-52%.
• Confirmation of mannose conjugation to chitosan via an alkane chain bridge (CH(2)CH(2)) using FT-IR and (1)H NMR.
• Mannose grafting slightly reduced chitosan's thermal stability.
• Man-chitosan exhibited low cytotoxicity against tested liver cancer cell lines.

Conclusions:

• A practical and controllable laboratory method for Man-chitosan synthesis was established.
• The synthesized Man-chitosan is structurally confirmed and exhibits favorable low cytotoxicity.
• Man-chitosan presents potential for development in biomedical fields, particularly where biocompatibility is crucial.