Topography-driven bionano-interactions on colloidal silica nanoparticles

Abstract

We report here that the surface topography of colloidal mesoporous silica nanoparticles (MSNs) plays a key role on their bionano-interactions by driving the adsorption of biomolecules on the nanoparticle through a matching mechanism between the surface cavities characteristics and the biomolecules stereochemistry. This conclusion was drawn by analyzing the biophysicochemical properties of colloidal MSNs in the presence of single biomolecules, such as alginate or bovine serum albumin (BSA), as well as dispersed in a complex biofluid, such as human blood plasma. When dispersed in phosphate buffered saline media containing alginate or BSA, monodisperse spherical MSNs interact with linear biopolymers such as alginate and with a globular protein such as bovine serum albumin (BSA) independently of the surface charge sign (i.e. positive or negative), thus leading to a decrease in the surface energy and to the colloidal stabilization of these nanoparticles. In contrast, silica nanoparticles with irregular surface topographies are not colloidally stabilized in the presence of alginate but they are electrosterically stabilized by BSA through a sorption mechanism that implies reversible conformation changes of the protein, as evidenced by circular dichroism (CD). The match between the biomolecule size and stereochemistry with the nanoparticle surface cavities characteristics reflects on the nanoparticle surface area that is accessible for each biomolecule to interact and stabilize any non-rigid nanoparticles. On the other hand, in contact with variety of biomolecules such as those present in blood plasma (55%), MSNs are colloidally stabilized regardless of the topography and surface charge, although the identity of the protein corona responsible for this stabilization is influenced by the surface topography and surface charge. Therefore, the biofluid in which nanoparticles are introduced plays an important role on their physicochemical behavior synergistically with their inherent characteristics (e.g., surface topography).

Monitoring the Hemolytic Effect of Mesoporous Silica Nanoparticles after Human Blood Protein Corona Formation

“…human plasma), the negative charge observed in the zeta potential assays indicates a preference for the adsorption of negative charged proteins on the nanoparticles. This physicochemical tendency was previously observed for silica nanoparticles of this kind 24. The zeta potential value of MSN‐SiOH (bare) in PBS solution is –12.2 mV ± 1.9.…”

“…This result is related to the fact that the protein adsorption will change the surface microchemical environment of the nanoparticle completely, thus constituting a major element in the final biological identity of the nanoparticle 23. This adsorption also has a strong relation with the surface features of the nanoparticle, such as charge and topography, as well as with the physicochemical characteristics of the protein in solution, which are utterly related to the molecular structure, weight, chain length, and stereochemistry of the protein 7,24. Considering the last aspects, the influence of different proteins [human serum albumin (HSA), human plasma (HP), human hemoglobin (Hb), and RBC lysate (HL)] on the hemolytic activity of MSN‐SiOH after the formation of the protein corona was evaluated.…”

Silver Nanocoatings at Large Length Scales: Influence of the AgNPs Morphology and Capping Agents on the Coating Chemical Stability and Antimicrobial Effect

“…[6][7][8]49 The attractive interactions (mainly van der Waals) may overcome possible electrostatic repulsion between the AgNPs and the substrate surface, since the latter had, to some extent, negatively charged groups covering the surface (by the deprotonation of silanol groups at neutral pH). 8,50,51 The predominance of these types of interactions over electrostatic repulsion has previously been observed for an adsorbate (i.e. peptide molecules) when its concentration is above a certain threshold.…”

“…In the particular case of biogenic AgNPs (Ag-Glutinis and Ag-Mucilaginosa), the colloidal stabilization by steric/electrosteric mechanisms must also be accounted due to the presence of macromolecules in the protein corona. 8,48 Assessment of the AgNPs coatings at multiple scales with LF X-ray imaging…”

“…electrostatic, hydrophobic, hydrogen bonds and van der Waals) between the nanoparticles and solid surfaces. [6][7][8] Essentially, bio-AgNPs are formed from interaction mechanisms ruled by proteins present in the bacterial/ fungal extract or filtrate, which drive the bio-AgNPs' nucleation → growth → colloidal stabilization steps. 2,9,10 At the end of the kinetic process, a protein corona phase on the bio-AgNPs provides a long-term colloidal stability.…”