Recent Advances in Carbon Nanotubes for Nervous Tissue Regeneration

Table 1

Toxicity study of various carbon nanotubes solubilization and functionalisation schemes of biological interest.

Small molecules as solubilizing agents	Toxicity	Reference
Tetrahydrofuran	Tumorigen, mutagen	[71]
Dichlorocarbene	Harmful	[71]
Anthracene	Possible tumor promoter	[72]
Pyrene	Carcinogenic, mutagenic	[73]
Zn-porphyrin	Unknown, likely safe	[74]
Phenylethyl alcohol	Topical irritant	[75]
n-octyl-β-d-glucoside	Unknown	[76]
n-decanoyl-N-methylglucamide	Unknown	[76]
Triaminopyrimidine	Unknown	[77]
Lysophosphatidylcholine	Unknown	[77]
Barbituric acid	Not pharmacologically active	[78]
Sodium cholate	Unknown	[76]
Taurine	Safe up to ∼28.57 mg/mL	[79]
Thiolated organosilane	Unknown	[80]
Macromolecules as solubilizing agents	Toxicity	Reference
Chitosan	Mostly safe	[81]
Helical amylase	Unknown	[82]
Poly(phenyleneethynylene)	Possible antimicrobial properties	[83]
Poly(aminobenzene sulfonic acid)	Hazardous to blood, nervous system, liver	[84]
PAA	Severely irritating and corrosive	[85]
PEG	Acute oral and dermal	[84]
Sulfonated polyaniline	Unknown	[86]
Functionalisation approach	Toxicity	Reference
MWCNT-NH3^+	Weak transient inflammatory response on glial cells	[87]
^13C enriched SWCNTs + Tween-80 1%	Moderate (mouse lungs and liver), biodistribution study	[88]
PEG-modified SWCNTs	Mostly safe (spinal cord injury)	[89]
[^111In]DTPA-MWCNTs	Not determined (blood-brain barrier in vitro model)	[90]
PEG-oligodeoxynucleotide (CpG)	Mostly safe (glioma tumor model)	[91]

PEG: polyethylene glycol; PAA: poly(acrylic acid); DTPA: diethylenetriaminepentaacetic acid.