A Study Of The Physicochemical Properties Of Dense And Mesoporous Silica Nanoparticles That Impact Protein Adsorption From Biological Fluids

At the intersection of materials chemistry and biology, biomaterials have been successfully employed in an array of medical applications. From diagnostic tools to targeted drug delivery, the modular physical and chemical properties of these materials provide numerous applications. For example, porous nanoparticles have been widely integrated as vehicles to carry chemotherapeutics to localized tumor sites. By encapsulating these cytotoxic compounds within a porous framework, the commonly associated adverse side effects of conventional chemotherapeutics, such as Doxorubicin, have been greatly reduced. One such material, mesoporous silica, has received widespread attention due to its excellent biocompatibility, high surface area to mass ratio, tunable pore diameters and volumes, and robust surface chemistry. However, recent studies have demonstrated that exposing silica nanoparticles, and other synthetic materials, to biological milieu envelops the particles in layers of proteins and biomolecules. The resulting protein coat, known as the protein corona , has been shown to have profound effects on bioavailability, cellular targeting, and cytotoxicity. Thus, in order to develop safe and effective particle-based therapies, it is of utmost importance to establish a more thorough understanding of this process. To examine how changes in surface chemistry influence protein adsorption, monodisperse, spherical mesoporous silica nanoparticles, ca. 50 nm, were modified with a variety of surface functionalizations, -NH2, -COOH, and -PEG. Exposing these materials to biological fluid revealed drastically different protein fingerprints, suggesting a strong correlation between the surface chemistry and the identity and composition of the protein corona. Quantification of the protein corona, i.e. mg protein/mg particles, was then achieved by performing thermogravimetric analysis. These values, in concert with spectral counts obtained by shotgun proteomics, illustrates a method for quantifying individual proteins present in the corona. Spherical, silica particles of varying diameters, 70-900 nm, were then synthesized to investigate how particle diameter may affect the biomolecular identity of the protein corona. Applying the previously described methods, it was found that mesoporous particles exhibit a higher affinity for low-molecular weight proteins compared to dense silica particles of similar diameters. Finally, stochastic optical reconstruction microscopy (STORM) was used to map protein adsorption/diffusion throughout as-prepared (pore diameter ~ 30 Å) .and large pore (pore diameter \u3e 60 Å) mesoporous silica particles. By collecting three-dimensional data on the protein-adsorbed materials, a sphere-fitting algorithm could be applied to determine the center and radius of the host particle. This calculation demonstrated that the depth by which specific proteins diffused into the porous framework was a function of both the protein\u27s molecular weight as well as the pore diameter

Effect of surface properties in protein corona development on mesoporous silica nanoparticles

[EN] The composition of the protein corona formed on mesoporous silica nanoparticles with several surface modifications was characterized. Low MW serum proteins were preferentially adsorbed, and PEGylated nanoparticles did not adsorb protein regardless of PEG chain length.The authors are thankful for financial support by the Spanish Ministry of Economy and Competiveness (projects SEV-2012-0267, MAT2012-39290-C02-02 and IPT-2012-0574-300000) and by the University of Vermont.Clemments, AM.; Muniesa Lajara, C.; Landry, CC.; Botella Asuncion, P. (2014). Effect of surface properties in protein corona development on mesoporous silica nanoparticles. RSC Advances. 4(55):29134-29138. https://doi.org/10.1039/c4ra03277bS291342913845

Protein Corona over Mesoporous Silica Nanoparticles: Influence of the Pore Diameter on Competitive Adsorption and Application to Prostate Cancer Diagnostics

[EN] Diagnostic tests based on proteomics analysis can have significant advantages over more traditional biochemical tests. However, low molecular weight (MW) protein biomarkers are difficult to identify by standard mass spectrometric analysis, as they are usually present at low concentrations and are masked by more abundant resident proteins. We have previously shown that mesoporous silica nanoparticles are able to capture a predominantly low MW protein fraction from the serum, as compared to the protein corona (PC) adsorbed onto dense silica nanoparticles. In this study, we begin by further investigating this effect using liquid chromatography-mass spectrometry (LC-MS)/MS and thermogravimetric analysis (TGA) to compare the MW of the proteins in the coronas of mesoporous silica nanoparticles with the same particle size but different pore diameters. Next, we examine the process by which two proteins, one small and one large, adsorb onto these mesoporous silica nanoparticles to establish a theory of why the corona becomes enriched in low MW proteins. Finally, we use this information to develop a novel system for the diagnosis of prostate cancer. An elastic net statistical model was applied to LC-MS/MS protein coronas from the serum of 22 cancer patients, identifying proteins specific to each patient group. These studies help to explain why low MW proteins predominate in the coronas of mesoporous silica nanoparticles, and they illustrate the ability of this information to supplement more traditional diagnostic tests.Financial support from the University of Vermont, the Spanish Ministry of Economy and Competitiveness (projects TEC2016-80976-R and SEV-2016-0683), and the Generalitat Valenciana (project PROMETEO/2017/060), is gratefully acknowledged. We thank Dr. Jaime Font de Mora for his assistance in the clinical sample collection and Dr. David Herva ' s for the statistical study supervision. We also appreciate the assistance of the electron microscopy service of the Universitat Politecnica de Valencia.Vidaurre Agut, CM.; Rivero-Buceta, EM.; Romaní-Cubells, E.; Clemments, AM.; Vera Donoso, CD.; Landry, C.; Botella Asuncion, P. (2019). Protein Corona over Mesoporous Silica Nanoparticles: Influence of the Pore Diameter on Competitive Adsorption and Application to Prostate Cancer Diagnostics. ACS Omega. 4(5):8852-8861. https://doi.org/10.1021/acsomega.9b00460S885288614