# Novel Chitosan Derivatives and Their Multifaceted Biological Applications
## 3 Biological Applications of ChDs
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Novel Chitosan Derivative Type** & \
\begin{tabular}{c} **Biological** \\ **Application** \\ \end{tabular} &
\begin{tabular}{c} **Bio-Functionality** \\ \end{tabular} & **Reference** \\ \hline Novel films based on & Antioxidant & Stronger antioxidant properties than chitosan & \\ sulfonamide-chitosan derivatives & Swelling Ratio & and other film derivatives. & [109] \\ \hline Amino-pyridine & & Highest swelling ratio & \\ functionalized chitosan & & Stronger radical (DPPH and hydroxyl) & \\ quaternary ammonium & Antioxidant & scavenging activity than chitosan. & [110] \\ derivatives & & & \\ \hline Double quaternized & Antioxidant & Stronger radical (DPPH, hydroxyl, and & \\ chitosan derivatives & & superoxide) scavenging activity. & [111] \\ \hline Chitosan derivatives with & & Higher radical (DPPH, hydroxyl, and & \\
1,2,3-Triazolium & Antioxidant & superoxide) scavenging activity than chitosan. & [112] \\ \hline Pyridylurea-functionalized & Antioxidant & Enhanced antioxidant activity than & \\ chitosan derivatives & Cytotoxicity & N-pyridylurea chitosan derivatives. & [113] \\ \cline{2-3}  & Cytotoxicity & Low cytotoxicity to I 292 cells. & \\ \hline Carboxymethyl chitosan & Antioxidant & Higher antioxidant activities. & [114] \\ derivatives & Cytotoxicity & Viability of I292 cells not affected. & [114] \\ with thiourea salts & & & \\ \hline N, O-selenized N-(2-carboxytyl) & Antioxidant & Strong antioxidant properties & \\ chitosan 1, 2 and 3 & Cytotoxicity & Caco-2 cell viability unaffected & [115] \\ \hline Water-soluble chitosan with & & & \\
4-fluorescein-carboxaldehyde/N- & Bio-imaging & Used to detect of Fe3+ in water and living & [116] \\ methyl-carbazole-3-aldehyde & & MCF-7 cells. & [116] \\ \hline Chitosan with phenolic & & & \\ hydroxyl groups & Cytotoxicity & Low toxicity to L929 cells. & [117] \\ \hline Oligo-chitosan & & & \\ N,O-carboxymethylchitosan & Cytotoxicity & Excellent cytocompatibility and cell viability. & [118] \\ N-carboxymethyl-chitosan & & & \\ \hline Water soluble phosphonium & & Low toxicity to L92 cell lines & \\ chitosan derivatives & Cytotoxicity & (mouse fibroblasts). & [119] \\ \hline Norcantharidin-conjugated & & Conjugate 1 was more cytotoxic to the human & \\ chitosan conjugate 1 & & gastric cancer cell line (MGC80-3) than & [120] \\ Norcantharidin-conjugated & & conjugate 2. & \\ chitosan conjugate 2 & & & \\ \hline Raloxifene–chitosan conjugate & & & \\ (Run 3 and 6) & Cytotoxicity & Both low toxicity to MCF-7 cells. & [121] \\ \hline Thiolated methylated N-(4-N,N- & & \\ dimethylaminobenzbenzyl) chitosan & Cytotoxicity & Did not affect the viability of human & \\ \hline Aminophosphionate-containing & & embryonic kidney 293 cells. & [122] \\ chitosan polymer derivatives & & & \\ \hline N-mPEG-N-octyl-O-sulfate & & & \\ chitosan derivatives & Drug delivery & The highest paclitaxel (3.94 mg/mL) was & [124] \\ \hline Novel films based on & Antioxidant & Stronger antioxidant properties than chitosan & \\ sulfonamide-chitosan derivatives & & and other film derivatives. & [109] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Antioxidant, cytotoxic, drug delivery applications of various novel chitosan derivatives.