Intraparticle Transport and Release of Dextran in Silica Spheres with Cylindrical Mesopores

Abstract

The transport of oligomeric molecules in silica spheres with cylindrical mesopores has been quantified and related to the structural features of the spherical particles and the interactions at the solid-liquid interface. An emulsion-solvent evaporation method was used to produce silica spheres having cylindrical mesopores with an average pore diameter of 6.5 nm. The transport of dextran molecules (fluorescently tagged) with molecular weights of 3000 and 10,000 g/mol was quantified using confocal laser scanning microscopy (CLSM). The intraparticle concentration profiles in the dextran-containing spheres were flat at all times, suggesting that the release is not isotropic and not limited by diffusion. The release of dextran into the solution is characterized by an initial burst, followed by long-term sustained release. The release follows a logarithmic time dependency, which was rationalized by coupling concentration-dependent effective diffusion constants with adsorption/desorption.

Ordered Mesoporous Polymer−Silica Hybrid Nanoparticles as Vehicles for the Intracellular Controlled Release of Macromolecules

“…30 This is still smaller than the pore diameter of PMAA/ SBA-15 PSN (11.7 nm), which is thus sufficient to permit diffusion of 40 kDa FITC-Dextran molecules inside the mesopores of PSNs. 31,32 As shown in Figure 3a, the S BET is the BET specific surface area calculated in the range of relative pressures from 0.05 to 0.2; V t is the total pore volume calculated at the relative pressure of about 0.95; w BJH is the diameter of mesopores calculated using the BJH method. b Hydrodynamic particle size from dynamic light scattering (DLS) measurements.…”

“…The estimated hydrodynamic diameter of 40 kDa FITC-Dextran is approximately 8 nm . This is still smaller than the pore diameter of PMAA/SBA-15 PSN (11.7 nm), which is thus sufficient to permit diffusion of 40 kDa FITC-Dextran molecules inside the mesopores of PSNs. , As shown in Figure a, the adsorption ability of the PSN material for FITC-Dextran was dependent on the pH of the loading suspension. Low pH solutions (pH < 5) lead to high loading of FITC-Dextran into the PSNs.…”

“…30 This is still smaller than the pore diameter of PMAA/ SBA-15 PSN (11.7 nm), which is thus sufficient to permit diffusion of 40 kDa FITC-Dextran molecules inside the mesopores of PSNs. 31,32 As shown in Figure 3a, the…”

Load–release of small and macromolecules from elastomers with reversible gyroid mesoporosity

“…(A similar slow release has been observed for dextran out of mesoporous silica.) 34 In methanol, however, the corresponding time was 7 min and comparable to the time scale of single SDS molecules' uninterrupted diffusion along the pores, without adsorption onto the pore walls. 24 The short release time scale for d-PEG and d-SDS out of the present collapsing nanoporous 1,2-PB is therefore hinting to diffusion without adsorption as the dominating regime of release.…”

Colloidal shuttles for programmable cargo transport

“…This is key to establish the non-equilibrium conditions that drive vital functions in living organisms 4 . Controlling cargo transport 5 and the spatial distribution of particles and molecules 6 , 7 in thermal systems can be a powerful tool to manipulate the chemical environment in modern analytical technologies 8 for medical diagnosis 9 and drug discovery, such as organ-on-a-chip devices 10 – 13 .…”