Abstract
The surface charge of a biomaterial represents a promising tool to direct cellular behavior, which is crucial for therapeutic approaches in regenerative medicine. To expand the understanding of how the material surface charge affects protein adsorption and mesenchymal stem cell behavior, differently charged surfaces with zeta potentials spanning from −25 mV to +15 mV were fabricated by the conjugation of poly(amidoamine) to alginate-based hydrogels. We showed that the increase of the biomaterials surface charge resulted in enhanced quantities of biologically available, surface-attached proteins. Since different surface charges were equalized after protein adsorption, mesenchymal stem cells interacted rather with diverse protein compositions instead of different surface features. Besides an enhanced cell attachment to increasingly positively charged surfaces, the cell spreading area and the expression of adhesion-related genes integrin α5 and tensin 1 were found to be increased after adhesion. Moreover, first results indicate a potential impact of the surface charge on mesenchymal stem cell differentiation towards bone and fat cells. The improved understanding of surface charge-related cell behavior has significant impact on the design of biomedical devices and artificial organs.
Highlights
In the last years, interfaces between biomaterials and cells gained increasingly in importance for a wide range of medical and pharmaceutical applications
After proteins attached to differently charged surfaces, the zeta potentials of all treated surfaces were equalized at −8.01 ± 2.38 mV (Fig. 1b)
Charged surfaces were fabricated by the conjugation of PAMAM to alginate-based hydrogels and enabled extensive studies regarding the effect of surface charges on protein adsorption and cell behavior of mesenchymal stem cells (MSCs)
Summary
Interfaces between biomaterials and cells gained increasingly in importance for a wide range of medical and pharmaceutical applications (reviewed in [1, 2]). Cells do not interact with the surface alone but rather with surface-attached proteins through direct binding to receptors within the cellular membrane [3]. Besides surface characteristics such as wettability [4], topography [5] and chemistry [6], the material surface charge is associated as a 105 Page 2 of 13. Since proteins and cell membranes are net negatively charged due to the presence of phospholipids, proteins and polysaccharide conjugates [16], appropriate surface charges for cell-matrix contacts are net positive
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
