Modification of halloysite clay nanotubes with various alkyl halides, and their characterization, blood compatibility, biocompatibility, and genotoxicity

Halloysite nanotubes (HNTs) clay were modified with alkyl halides, bromoethane (BrE), bromodecane (BrD), and bromooctadecane (BrOD), respectively. The FT-IR spectra of modified HNTs demonstrated an increase in the intensity of aliphatic -CH2 peaks at 2920 and 2850 cm(-1) proportional to the number of C atoms in the modifying agent confirming the success of chemical modification with corresponding alkyl halides. Surface charge of NaOH treated HNTs, -65.7 +/- 5.1 mV was increased to -37.1 +/- 2.4, -40.6 +/- 5.3, and -44.7 +/- 1.9 mV, respectively upon chemical modification with BrE, BrD, and BrOD. The Surface area of the HNT clays, 43.2 +/- 1.3 m(2)/g was also increased to 59.8 +/- 2.7, 56.9 +/- 2.1, and 47.9 +/- 1.7 m(2)/g for BrE, BrD, and BrOD modified HNT clays, respectively. Base-activated HNT clays at 1 mg/mL concentration found to be nonhemolytic with 3.5 +/- 1.2% hemolysis ratio, whereas HNT-BrOD clays were slightly exceeded hemolytic safety level with 6.6 +/- 0.2% hemolysis induction. Base-activated HNT and HNT-BrOD clays were found to show antithrombogenic character with more than 100% blood clotting indexes,107.6 +/- 1.8, and 106.5 +/- 1.9%, respectively. Cytotoxicity studies of HNTs on L929 fibroblast cells revealed that HNTs in 12.5-200 mu g/mL concentration range were shown dose-dependent cell viability, and above 50% cell viability was maintained at 200 mu g/mL in all forms of HNT based clays administered.

Automated summary

The modification of Halloysite nanotubes (HNTs) clay with alkyl halides resulted in changes in physical and chemical properties, including increased surface charge and surface area. HNT-BrOD clays showed slight hemolytic activity at certain concentrations, while both base-activated HNT and HNT-BrOD clays exhibited antithrombotic characteristics.