Folic acid (FA) based conjugate systems are frequently used in anticancer drug delivery because of its increased potential for internalization by receptor mediated endocytosis into the cancer cells. The conjugation reaction between conjugating polymer and FA depends on many reaction parameters that affect the degree of conjugation. In this study, an approach to synthesize FA-chitosan (CS) conjugate system was undertaken.
FA-chitosan (CS) conjugate system based on carbodiimide chemistry was developed by conjugating the free carboxyl group of folic acid moiety and primary amine group of CS. Two parameters were optimized: (i) reaction duration [4 to 48 h] and (ii) concentration of N-hydroxysuccinimide [0.25-1.00 g] to know their effect on percentage of conjugation. The conjugate formed was confirmed by FT-IR, and percentage conjugation of FA was analyzed by UV spectroscopy. The highly conjugated FA-CS system was further characterized by XRD, DSC and TGA. The morphology and bio-compatibility parameters were also studied by SEM and MTT assay, respectively.
We found that conjugation was efficient when the reaction duration and NHS concentration were ≥24 h and 0.75 g, respectively. The bio-conjugate system formed was more amorphous as confirmed by XRD, DSC and TGA analysis. The conjugated material did not exhibit any cytotoxicity in HeLa cells.
The results showed a potential to be used this material in anti-cancer drug delivery application.
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All authors have declared no conflicts of interest.