Influence of Pore Size and Surface Functionalization of Mesoporous Silica Nanoparticles on the Solubility and Antioxidant Activity of Confined Coenzyme Q10

Coenzyme Q10 is a potent antioxidant that plays an important role in the maintenance of various biochemical pathways of the body and has a wide range of therapeutic applications. However, it has low aqueous solubility and oral bioavailability. Mesoporous silica nanoparticles (MCM-41 and SBA-15 types) exhibiting varying pore sizes and modified with phosphonate and amino groups were used to study the influence of pore structure and surface chemistry on the solubility, in vitro release profile, and intracellular ROS inhibition activity of coenzyme Q10. The particles were thoroughly characterized to confirm the morphology, size, pore profile, functionalization, and drug loading. Surface modification with phosphonate functional groups was found to have the strongest impact on the solubility enhancement of coenzyme Q10 when compared to that of pristine and amino-modified particles. Phosphonate-modified MCM-41 nanoparticles (i.e., MCM-41-PO₃) induced significantly higher coenzyme Q10 solubility than the other particles studied. Furthermore, MCM-41-PO₃ led to a twofold decrease in ROS generation in human chondrocyte cells (C28/I2), compared to the free drug in a DMSO/DMEM mixture. The results confirmed the significant contribution of small pore size and negative surface charge of MSNs that enable coenzyme Q10 confinement to allow enhanced drug solubility and antioxidant activity.

Albumin-Coated Mesoporous Silica Nanoparticles of Docetaxel: Preparation, Characterization, and Pharmacokinetic Evaluation

The potential of albumin-coated hollow mesoporous silica nanoparticles (A-HMSNs) to optimize the chemotherapeutic efficacy of docetaxel (DTX) was explored. The synthesized A-DTX-HMSNs had a nanometric size range, offered large surface area with numerous pores, and offered high drug entrapment and loading, that is, 79.18% ± 1.4% and 19.11% ± 1.30%, respectively. Fourier transform infrared spectroscopy and differential scanning calorimetry studies confirmed drug loading and the presence of albumin onto the developed systems, and the drug release followed Higuchi profile. A-HMSNs significantly enhanced the pharmacokinetic profile of DTX by eightfold vis-à-vis the pure DTX. The enhanced plasma levels (C_max, T_max, area under the curve), prolonged drug release, long circulation time, lower clearance, hemocompatability, and substantially higher drug loading offered by these nanocarriers inherit promise of a safer and efficacious formulation of DTX.

Peptide Functionalization of Gold Nanoparticles for the Detection of Carcinoembryonic Antigen in Blood Plasma via SPR-Based Biosensor

Nanoparticles functionalized with specific biological recognition molecules play a major role for sensor response enhancement in surface plasmon resonance (SPR) based biosensors. The functionalization procedure of such nanoparticles is crucial, since it influences their interactions with the environment and determines their applicability to biomolecular detection in complex matrices. In this work we show how the ζ-potential (Zpot) of bio-functionalized gold spherical NPs (Bio-NPs) is related to the SPR sensor response enhancement of an immune-sandwich-assay for the detection of the carcinoembryonic antigen (CEA), a cancer marker for colorectal carcinomas. In particular, we prepare bio-functional nanoparticles by varying the amount of peptide (either streptavidin or antibody against CEA) bound on their surface. Specific and non-specific sensor responses, reproducibility, and colloidal stability of those bio-functional nanoparticles are measured via SPR and compared to ζ-potential values. Those parameters are first measured in buffer solution, then measured again when the surface of the biosensor is exposed to blood plasma, and finally when the nanoparticles are immersed in blood plasma and flowed overnight on the biosensor. We found that ζ-potential values can guide the design of bio-functional NPs with improved binding efficiency and reduced non-specific sensor response, suitable reproducibility and colloidal stability, even in complex matrixes like blood plasma.