Using an energetic ion beam, the team produced carbon nanotube arrays possessing similar microstructures, but vastly different surface hydrophilicity. This novel material provides a new platform for studying the complex interactions between biomolecules (for example, proteins) and carrier systems, and facilitates the design and development of advanced drug-delivery systems.

Retention and release

As shown in the images above, the pristine carbon nanotube arrays were superhydrophilic, but became superhydrophobic after energetic ion bombardment. When both arrays were used as carriers, the researchers found that the superhydrophilic versions retained a larger amount of rhBMP-2 than the superhydrophobic ones.

Use of a poloxamer diffusion layer on top of the loaded rhBMP-2 delayed the large initial burst that was commonly observed in conventional carriers and resulted in a greater total amount of rhBMP-2 released from both surfaces. Additionally, it was found that rhBMP-2 bound to the superhydrophilic carbon nanotube arrays remained bioactive while it denatured on the superhydrophobic arrays.

These properties could be considered for future development of next-generation drug-, gene- and protein-delivery systems to maximize their performance.

Full details can be found in the journal Nanotechnology.