Quantification of Uptake and Localization of Bovine Serum Albumin-Stabilized Single-Wall Carbon Nanotubes in Different Human Cell Types

Single-wall carbon nanotubes (SWCNTs) possess many unique, inherent properties that make them attractive materials for application in medical and biological technologies. Development of concentrated SWCNT dispersions of isolated nanotubes that retain SWCNTs' inherent properties with minimal negative cellular effects is essential to fully realize the potential of SWCNTs in biotechnology. It is shown that bovine serum albumin (BSA), a common and well-characterized model blood serum protein, can individually disperse SWCNTs at concentrations of up to 0.3 mg mL(-1) while retaining SWCNTs' optical properties. Uptake into human mesenchymal stem cells (hMSC) and HeLa cells is quantified, revealing strikingly high concentrations of 86 +/- 33 x 10(6) and 21 +/- 13 x 10(6) SWCNTs per cell, respectively, without any apparent acute deleterious cellular effects. Through high-resolution confocal Raman spectroscopy and imaging, it is established that SWCNT-BSAs are preferentially localized intracellularly, especially in the cytoplasm of both hMSCs and HeLa cells. The uptake and localization results demonstrate the efficacy of BSA as a biocompatible dispersant and a mediator of bioactivity. BSA is widely available and inexpensive, which make these concentrated, highly-dispersed, noncovalently modified SWCNT-BSAs suitable for the development of SWCNT-based biotechnologies.