Refluxed in acid nitric followed by thionyl chloride and then functionalized with PEG diamine
Doxorubicin (DOX) and fluorescein isothocyanate (FITC) as fluorescence labelling probes
Covalent
Human adenocarcinoma cells (HeLa), human hepatocellular carcinoma cells (HepG2) and human leukemia cells (K562)
The PEGylated MWCNTs penetrated into mammalian cells without damage plasma membrane and its accumulation did not affect cell proliferation as well as cell cycle distribution. It was found to accumulate in the multidrug-resistant cancer cells as efficient as in the sensitive cancer cells.
The f-SWCNTs were observed mostly accumulated in the cytoplasm, particularly near the mitochondria and in the Golgi bodies and cytoplasmic vacuoles of the f-SWCNTs treated cells.
Oxidized in concentrated sulfuric acid/nitric acid mixture and further functionalized with cationic polymer polyethylenimine (PEI)
Paclitaxel (PTX), folic acid (FA) as targeting ligand and QDs
Noncovalent/covalent
HeLa cells and human umbilical vein endothelial cells (HUVEC)
The f-MWCNTs-PTX enhanced cytotoxicity capability significantly and exhibited high targeting ability with good aqueous solubility and biocompatibility.
The obtained f-DOX-FA-CHI-SWCNTs demonstrated high therapeutic payloads and thus, it can kill the cancer cells effectively by releasing DOX at the reduced pH environment.
Functionalized with carboxylic acid followed by encapsulation with FA-conjugated CHI
DOX
Noncovalent
None
The conjugate demonstrated good stability in aqueous medium due to the encapsulation of CHI and exhibited the characteristics of both targeted and controlled release functions.
Oxidized in oleum and nitric acid and subsequently functionalized with methoxy (PEG) amine
PTX
Non-covalent
It was found that the conjugate was not acutely toxic, primarily accumulated in the liver and spleen and proved to be stable and effective both in vitro and in vivo.
Purified using sulfuric acid/nitric acid mixture and further functionalized with polycitric acid-polyethylene glycol-polycitric acid (PCA-PEG-PCA) linear-dendritic copolymers
Cisplatin (cis-diamminedichloroplatinum) (CDDP)
Noncovalent
Murine colon adenocarcinoma tumor cancer cells (C26)
The synthesized conjugate was able to be introduced into the colon cancer cells and kill the cells effectively.
Oxidized in concentrated sulfuric acid and nitric acid, followed by conjugation with iron nanoparticles
DOX and FA
Covalent
HeLa cells
The DOX/FA-MWCNT@Fe had a sufficient load capacity (32 g/mg) and a prolonged release property assisted by near infrared radiation. It also demonstrated both biologically (active) and magnetically (passive) targeting capabilities toward HeLa cells in vitro with ca. 6-fold higher delivery efficiency of DOX than free DOX.
Oxidized in nitric acid and sulfuric acid mixture and subsequently functionalized by 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG2000) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[maleimide(polyethylene glycol)-2000] (DSPE-PEG2000-MAL)
DOX and angiopep-2 as targeting ligand
Noncovalent
Brain capillary endothelial cells (BCEC) and glioma cells (C6)
The conjugate showed a better anti-glioma effect and a lower cardiac toxicity compared to DOX.
Carboxylation, acylation and followed by amidation process to obtain amine terminated MWCNTs
DOX and targeting moiety D--tocopheryl PEG 1000 succinate (vitamin E TPGS)
Noncovalent
Human breast cancer cells (MCF-7)
The formulation demonstrated enhanced cytotoxicity and mostly taken up by the cancer cells via endocytosis mechanism. It has longer survival span (44 days) compared to untargeted formulation (23 days) and free DOX (18 days).
The system can deliver a large amount of drug into cells and further preventing potential cytotoxicity effects of CNTs when administered at high dosage.
Acid oxidation in nitric acid and sulfuric acid mixture
CHI, bovine serum albumin (BSA) and FITC
Noncovalent
HeLa cells
The conjugate obtained good stability and dispersity in aqueous solution over 30 days. It is biocompatible with HeLa cells in which the cell viability is 81% after incubation with concentration 100 g mL−1 for 24 h incubation. BSA immobilization efficiency was found to be improved by 0.8 times and cellular toxicity was decreased by 50% compared with carboxylated MWCNTs.
Poly(acrylic acid) was grafted on MWCNTs through free radical polymerization
DOX, FA and iron oxide magnetic nanoparticles
Noncovalent
Human glioblastoma cells (U87)
The system demonstrated enhanced cytotoxicity toward U87 cells compared with free DOX. It was taken up by U87 cells with subsequent intracellular release of DOX, followed by transport of DOX into the nucleus leaving the nanocarrier in the cytoplasm.
Acid oxidation in nitric acid and sulfuric acid mixture
None
Covalent
Primary human umbilical vein endothelial cells (HUVE)
The f-SWCNTs had limited toxicity for HUVE cells in vitro and therefore, it could be used as a potential nanocarrier of antiangiogenic drugs for targeting the vasculature.
Phospholipids (PL) were covalently conjugated to hyaluronan (HA) via amine-coupling chemistry to obtain PL-HA conjugate
Noncovalent
Murine macrophages (RAW 264.7) and the epithelial colon adenocarcinoma cells (HCT 116)
The findings showed that the CNTs-PL-HA internalized into macrophages and exhibited low cytotoxicity. Furthermore, it did not induce pro-inflammatory cytokines or mitochondrial toxicity with leukocytes in contrast to non-modified CNTs.
Acid oxidation in nitric acid and sulfuric acid mixture
Carvedilol (CAR) and PAMAM dendrimers
Covalent
None
PAMAM-MWCNTs enhanced the drug-loading capacity as well as drug dissolution significantly and, hence, it could be developed as potential nanocarrier for poorly water-soluble drug.