Synthesis of ordered mesoporous silica MCM-41 with controlled morphology for potential application in controlled drug delivery systems

Abstract

MCM-41 is one of the most studied mesoporous ceramics for drug delivery systems. Its high specific surface area and mesoporosity allow high adsorption capacity. Even though there are many studies published in the biomedical field, there are no reports of commercial applications of MCM-41 so far. One of the possible justifications is the lack of morphological control during conventional synthesis. Therefore, modifications in the reaction parameters of the MCM-41 conventional synthesis were tested in this paper, aiming to obtain particles with reduced diameter and agglomeration. It was observed that both the increase in the water molar proportion and the decrease in the stirring time resulted in particles with reduced size. Furthermore, the control of the tetraethyl orthosilicate (TEOS) dropping rate and the addition of triethylamine (TEA) improved the dispersion of the system, but they also decreased the particle size, and therefore van der Waals interactions promoted re-agglomeration.

Biodiesel production on bench scale from different sources of waste oils by using NiZn magnetic heterogeneous nanocatalyst

“…Studies report that the presence of mesoporous improves the performance of the catalyst since the diffusion of FFA inside and outside the catalyst is facilitated by the presence of mesoporos 16,68 . Finally, for P / P 0 above 0.8, the adsorbed volume may be attributed to the filling of the voids between the particles that can be considered as porosity 41,69 . The formation of an isotherm with a well‐defined hysteresis loop, as observed in this work, can be attributed to the capillary condensation that occurs because of the delay in pore condensation.…”

Evaluation of mesostructured silica materials with different structures and morphologies as carriers for quercetin and naringin encapsulation

“…2c). Therefore, this was the least optimum ratio, because as the concentration of carrier increased, the adsorption capacity of MSU-2 was reduced, as explained above for SBA-15 [20,[55][56][57][58]. Regarding the other ratios, although they had similar encapsulation efficiency, the silica/analyte ratio 1:5 clearly showed higher adsorption capacity than the silica/analyte ratio 1:1 (Fig.…”

“…2 Adsorption (loading) kinetics obtained for quercetin and naringin using different mesostructured silicas as carriers at different silica/analyte ratios. Ratio 5:1 = 250 mg silica/50 mg analyte; ratio 1:1 = 50 mg silica/50 mg analyte; ratio 1:5 = 10 mg silica/50 mg analyte [58]. Consequently, this prevents free access of the analytes to the entire surface or the entry of the pores of the material when there is a high number of silica particles in the media, which hinders the mass transfer process to the internal parts of the agglomerates.…”

Silica‐Based Nanoparticles as Drug Delivery Vehicles for Prostate Cancer Treatment

“…These materials needs further modification and downsizing for increasing the blood circulation time for cancer therapy and taking advantage of the EPR effect. [100][101][102][103] Several modifications of this process have since been developed with the discovery of other mesoporous materials with different structures including SBA-15, KIT-6, KIT-5, SBA-1. [104][105][106][107][108][109] The size, shape and porosities are controlled by a slight variation of synthesis procedures and the use of different surfactant templates.…”

“…While MCM‐41 based materials are popular for drug delivery especially in oral delivery routes, the only drawback of the MCM‐41 and other families of materials synthesized initially was the irregular shape, polydispersity, lack of stable dispersion and large size of the particles. These materials needs further modification and downsizing for increasing the blood circulation time for cancer therapy and taking advantage of the EPR effect [100–103] . Several modifications of this process have since been developed with the discovery of other mesoporous materials with different structures including SBA‐15, KIT‐6, KIT‐5, SBA‐1 [104–109] .…”