Quantitative interpretation of PAMAM dendrimers adsorption on silica surface

Understanding the dendrimer-solid support interaction is of great importance for dendrimer-based drug delivery system design. The maximum surface coverage on a hydrophilic silica surface was determined using the quartz crystal microbalance with dissipation monitoring (QCM-D) and multi-parametric surface plasmon resonance (MP-SPR) methods: the adsorption process depends on ionic strength and pH of solutions. The effectiveness of G6 adsorption is mainly determined by the range of electrostatic inter-dendrimer interactions and dendrimer-silica surface interactions. Changes in ionic strength have a strong effect on the binding affinity of dendrimers to the surface. The trends in the binding affinity and the surface saturation amount correspond well with the degree of change of protonation of the adsorbed molecules. The development of new research techniques makes it possible to attain a more profound understanding of the self-assembling behaviour of dendrimers. The comparison of QCM-D and MP-SPR allowed the estimation that the dendrimer film contains approximately 70% water. These results indicate that 6th generation PAMAM dendrimers form very hydrated films on silica surfaces. In this case the number of water molecules associated per dendrimer molecule varied from 10,450 to 9,200. The hydration of dendrimer films seems to be a crucial aspect of their implementation. This data confirmed that dendrimers are very promising candidates for many biological applications.

Publication year: 2017
Authors: Tokarczyk K., Jachimska B

J. Haber Institute of Catalysis and Surface Chemistry, PAS, Niezapominajek 8, 30-239 Cracow, Poland

Published in: Journal of Colloid and Interface Science, 2017 Vol. 503, p. 86-94
DOI: 10.1016/j.jcis.2017.05.002


bound mass dendrimer-solid support interaction drug delivery effect of ionic strength effect of pH LayerSolver macromolecules adsorption PAMAM dendrimers binding QCM SiO2 sensor slide surface coverage water content


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