Stabilisation of SWNTs by alkyl-sulfate chitosan derivatives of different molecular weight: towards the preparation of hybrids with anticoagulant properties.
We have previously demonstrated that chitosan derivative N-octyl-O-sulfate chitosan (NOSC), which presents important pharmacological properties, can suspend single walled carbon nanotubes (SWNTs) up to 20 times more effectively than other chitosan derivatives in an aqueous environment. In an attempt to further investigate the impact of different molecular weights of chitosan to the solubilization and anticoagulant properties of these hybrids an array of NOSC derivatives varying their molecular weight (low, medium and high respectively) was synthesised and characterised by means of FT-IR spectroscopy, NMR spectroscopy and thermal gravimetric analysis (TGA). Microwave and nitric acid purified SWNTs, characterised by FT-IR spectroscopy, transmission electron microscopy (TEM) and Raman spectroscopy, were colloidally stabilised by these polymers and their anticoagulant activity was assessed. The results revealed that the low molecular weight NOSC coated SWNTs exhibit the highest activity when 0.5 mg mL(-1) NOSC solutions are used, activity which is similar to that of the free polymer. Preliminary studies by exposure of these hybrids to Brine Shrimp (Artemia) cysts revealed no effect on the viability of sub-adult Artemia. Our findings suggest the possibility of tailoring these nanomaterials to bear the required properties for application as biocompatible building blocks for nanodevices including biosensors and biomaterials.
School of Pharmacy and Biomedical Sciences, University of Portsmouth, St. Michael's Building, White Swan Road, Portsmouth, PO1 2DT, UK.
Dimitrios G
DG
Fatouros
Kieron
K
Power
Omar
O
Kadir
Imre
I
Dékány
Spyros N
SN
Yannopoulos
Nikolaos
N
Bouropoulos
Aristides
A
Bakandritsos
Milan D
MD
Antonijevic
George D
GD
Zouganelis
Marta
M
Roldo
D000925:Anticoagulants / Q000138:chemical synthesis / Q000494:pharmacology; D001777:Blood Coagulation / Q000187:drug effects*; D048271:Chitosan / Q000737:chemistry* / Q000494:pharmacology*; D005079:Excipients / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008970:Molecular Weight; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size
D000925:Anticoagulants; D005079:Excipients; D037742:Nanotubes, Carbon; D048271:Chitosan