Multifunctional polymer drug loading system with pH-sensitive, fluorescent and targeting property

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Nanotechnology

Background:

• Chitosan-based drug delivery systems offer biocompatibility and biodegradability.
• Developing multifunctional drug carriers with pH-sensitivity, fluorescence, and targeting capabilities is crucial for targeted cancer therapy.

Purpose of the Study:

• To fabricate a multifunctional drug loading system based on modified chitosan.
• To incorporate pH-sensitivity, fluorescence, and targeting moieties into the chitosan carrier.
• To evaluate the drug encapsulation efficiency and release profile of the developed system.

Main Methods:

• Synthesis of amphipathic N-octyl-N'-(2-carboxyl-cyclohexamethenyl) chitosan (OCCC).
• Modification of OCCC with folic acid (FA) and thiazole orange (TO) via polyethylene glycol (PEG) linkers.
• Characterization of chemical structure and properties using FT-IR, elemental analysis, DSC, UV-vis, and fluorescence spectroscopy.
• Encapsulation of 5-fluorouracil and assessment of drug release under varying pH conditions.

Main Results:

• Successful synthesis and characterization of the TO-PEG-OCCC-PEG-FA multifunctional system.
• Achieved high encapsulation efficiency of 42.76% for 5-fluorouracil at a concentration of 10mg/mL.
• Demonstrated excellent pH-sensitive drug release, with up to 95% release within 4 hours in an acidic environment (pH=4.0), while remaining stable at physiological pH (pH=7.4).

Conclusions:

• The fabricated multifunctional chitosan micelle is a promising pH-sensitive, fluorescent, and targeted drug delivery vehicle.
• The system exhibits efficient drug loading and controlled release, particularly under acidic conditions characteristic of tumor microenvironments.
• This advanced drug delivery system holds potential for enhanced cancer therapy applications.