Highly Controlled Diffusion Drug Release from Ureasil–Poly(ethylene oxide)–Na⁺–Montmorillonite Hybrid Hydrogel Nanocomposites

Abstract

In this work, we report the effects of incorporation of variable amounts (1-20 wt %) of sodium montmorillonite (MMT) into a siloxane-poly(ethylene oxide) hybrid hydrogel prepared by the sol-gel route. The aim was to control the nanostructural features of the nanocomposite, improve the release profile of the sodium diclofenac (SDCF) drug, and optimize the swelling behavior of the hydrophilic matrix. The nanoscopic characteristics of the siloxane-cross-linked poly(ethylene oxide) network, the semicrystallinity of the hybrid, and the intercalated or exfoliated structure of the clay were investigated by X-ray diffraction, small-angle X-ray scattering, and differential scanning calorimetry. The correlation between the nanoscopic features of nanocomposites containing different amounts of MMT and the swelling behavior revealed the key role of exfoliated silicate in controlling the water uptake by means of a flow barrier effect. The release of the drug from the nanocomposite displayed a stepped pattern kinetically controlled by the diffusion of SDCF molecules through the mass transport barrier created by the exfoliated silicate. The sustained SDCF release provided by the hybrid hydrogel nanocomposite could be useful for the prolonged treatment of painful conditions, such as arthritis, sprains and strains, gout, migraine, and pain after surgical procedures.

Two-dimensional nanomaterials: fascinating materials in biomedical field

“…Moreover, compared with other vectors, silicate clays are safe and high efficient therapy carriers to validly avoid severe immunological and toxicological responses [92,93]. Recently, Jesus et al [94] constructed a clay-based nanocomposite by incorporating sodium montmorillonite (MMT) into a hybrid hydrogel of siloxane-poly(ethylene oxide) to deliver sodium diclofenac (SDCF). This hybrid hydrogel nanocomposite could realize the sustained release of SDCF, offering the possibility of long-term treatment of arthritis, sprains, gout, migraine, and postoperative pain.…”

Clay-Polymer Nanocomposites Prepared by Reactive Melt Extrusion for Sustained Drug Release

“…Increase in hygroscopicity above a clay-loading threshold was attributed to the nanoclay agglomeration effect [37]. The increase in water permeability can also be explained by the increasing level of nonexfoliated silicate layers that formed tactoids and intercalated structures [55]. Aggregates in the intercalated structure facilitated the diffusion of water molecules via the connecting pathways along the polymer-clay interfacial zones [56].…”

Synthesis of ureasil-polyether film forming materials by using environmentally friendly solvent

“…These hybrids are synthesized and processed through the chemical route known as solgel [9][10][11][12] . During the synthesis of precursors, the usually employed solvent is tetrahydrofuran (THF), which is widely used industrially.…”