Abstract
Standard cell culture plastic was surface modified by passive adsorption or covalent attachment of interleukin (IL)-4 and investigated for its ability to induce differentiation of human monocytes into mature dendritic cells, a process dose-dependently regulated by IL-4. Covalent attachment of IL-4 proceeded via anthraquinone photochemistry to introduce amine functionalities at the surface followed by coupling of IL-4 through a bifunctional amine-reactive linker. X-ray photoelectron spectroscopy showed that undesirable multilayer formation of the photoactive compound could be avoided by reaction in water instead of phosphate-buffered saline. Passively adsorbed IL-4 was observed to induce differentiation to dendritic cells, but analysis of cell culture supernatants revealed that leakage of IL-4 into solution could account for the differentiation observed. Covalent attachment resulted in bound IL-4 at similar concentrations to the passive adsorption process, as measured by enzyme-linked immunosorbent assays, and the bound IL-4 did not leak into solution to any measurable extent during cell culture. However, covalently bound IL-4 was incapable of inducing monocyte differentiation. This may be caused by IL-4 denaturation or improper epitope presentation induced by the immobilization process, or by biological irresponsiveness of monocytes to IL-4 in immobilized formats.
| Original language | English |
|---|---|
| Journal | Journal of Biomedical Materials Research. Part A |
| Volume | 96 |
| Issue number | 2 |
| Pages (from-to) | 372-83 |
| Number of pages | 12 |
| ISSN | 1549-3296 |
| DOIs | |
| Publication status | Published - Feb 2011 |
Keywords
- Adsorption
- Anthraquinones
- Cell Culture Techniques
- Cell Differentiation
- Dendritic Cells
- Down-Regulation
- Enzyme-Linked Immunosorbent Assay
- Humans
- Immobilized Proteins
- Interleukin-4
- Monocytes
- Plastics
- Solutions
- Surface Properties
- Triazines
- Up-Regulation
- Journal Article
- Research Support, Non-U.S. Gov't