Table 4.
Functionalized CNTs and Their Effect on Solubility, Toxicity, and Effective Cellular Internalization Mechanisms
| Functionalized-CNTs | Cell Types | Major Results | Ref. | |
|---|---|---|---|---|
| Solubility | SPAN-MWCNT | – | Weaker π-π bonds between CNTs and SPAN, and high solubility | [170] |
| Pl-PEG-SWCNT | Jurkat cell line | Increase in aqueous solubility by non-covalent functionalization of SWCNTs | [171] | |
| Cellular uptake | MWCNT-FITC | RAW 264.7 murine macrophages - A459 human lung carcinoma cells | Surface modification of CNTs can facilitate effective cellular uptake The ability of f-CNTs to cross the cell membrane of both cells at a 30–50% internalization rate |
[50] |
| Vitamin E TPGS-MWCNT (C6-CNTPC) | A549 cells | Increase in anticancer properties of DTX according to the phagocytosis mechanism of C6-CNTPC | [20] | |
| PEGylated CNT-ABT737 | A549 non-small cell lung cancer cells | Increase mitochondrial targeting with early endosomal escape, increase accumulation of complex in mitochondria and effective released drug | [87] | |
| Toxicity | SWCNT-PEG-THFF | D54MG-EGFP cells | This functional group protects D54MG-EGFP cells while the SWCNT backbone is harmful for these cells | [78] |
| CD-SWCNTs | MCF-7 and HeLa cells | Decreases the toxicity of CNTs and adverse side effects as a FMN drug delivery carrier | [90] | |
| FA- MWCNTs | HeLa cells | FA- MWCNTs are non-toxic to HeLa cells with cell viabilities more than 90% | [99] | |
| CH−β-GP–CNT hybrid hydrogels | 3T3 cells | Hydrogels containing CNTs (0.1%) showed no-toxicity in 3T3 cells with high cell viability | [103] | |
| SWCNT−PB (SPB) | 293T and A549 cells | SPB showed low cytotoxicity to both cell lines and more than an 80% cell viability at a high concentration of 50 μg mL−1 | [121] | |
| SWNT-PEG-PEI- AS1411 aptamer | L929 and AGS cells | This functionalized nanoplex showed low cytotoxicity in cells | [67] | |
| SWNT-PEI conjugates | N2A murine neuroblastoma cells | None of the SWNT-PEI110, and SWNT-PEI110 carriers had major cytotoxicity except SWNT-acyl-PEI1.8 (S1.8), SWNT-acyl-PEI10 (AC10) and SWNT-acyl-PEI25 (AC25) | [127] |
Abbreviations: Pl-PEG, phospholipid-PEG; FA, folic acid; CH, chitosan; β-GP, β-glycerophosphate; PB, PEI−betaine; SPAN, sulfonated polyaniline; FMN, formononetin.