| AVS 59th Annual International Symposium and Exhibition | |
| Biomaterial Interfaces | Monday Sessions |
| Session BI-MoM |
| Session: | Surfaces to Control Cell Response |
| Presenter: | R. Ogaki, Aarhus University, Denmark |
| Authors: | R. Ogaki, Aarhus University, Denmark O. Zoffmann Andersen, Aarhus University, Denmark K. Kolind, Aarhus University, Denmark D.C.E. Kraft, Aarhus University, Denmark M. Foss, Aarhus University, Denmark |
| Correspondent: | Click to Email |
Development of long-term stable surfaces that resist bio-adhesion continues to stimulate the field of biomedical and biological research. While numerous strategies have been developed over the last several decades, the challenge remains in the creation of surfaces that can provide long-term ‘zero’ bio-adhesion from a variety of biological entities that spans lengths scales from biomolecules to cells. Although the physical and chemical properties of the resisting surface itself are important in achieving this ultimate goal, assessing the extent of bio-adhesion must be accompanied by detailed surface analysis via highly sensitive analytical techniques.
We have recently discovered that increasing the temperature alone during the assembly process of poly-l-lysine grafted poly (ethylene glycol) (PLL-g-PEG) results in the formation of highly dense PLL-g-PEG brush coating. The PLL-g-PEG surfaces prepared at various temperatures (20 to 80 °C) have been characterized by X-ray photoelectron spectroscopy (XPS). The PLL-g-PEG surfaces prepared at the ‘standard’ temperature of 20 °C are found to be comparable to the previously reported literatures. Interestingly, the surfaces prepared at 80°C have shown the highest surface grafted density of PLL-g-PEG, with ~ 4 times denser than those prepared at 20 °C.
The degree of cell and protein adhesions on these surfaces has been stringently determined using cell culture and serum/blood adsorption assays combined with XPS and time of flight secondary ion mass spectrometry (ToF-SIMS). The temperature-induced PLL-g-PEG surfaces have achieved ‘zero’ cell adhesions from three different types of mammalian cells for at least 36 days. In addition, XPS and ToF-SIMS analysis have confirmed near-zero protein adsorptions from 10% serum/MEM (at least 36 days), whole undiluted blood (at least 24 hrs) and undiluted serum (at least 24 hrs) with the surfaces being pre-incubated in high ionic strength buffer (2.4 M NaCl for 24 hrs).
The outcome of the rigorous bio-resistance tests presented here highlights the critical importance of processing temperature on the surface graft density of electrostatically driven PLL-g-PEG. The temperature induced assembly process can be effectively and easily implemented for a range of biomedical and biotechnological applications.