Laponite as carrier for controlled in vitro delivery of dexamethasone in vitreous humor models

Abstract

Laponite clay is able to retain dexamethasone by simple physisorption, presumably accomplished by hydrogen bonding formation and/or complexation with sodium counterions, as shown by solid state NMR. The physisorption can be somehow modulated by changing the solvent in the adsorption process. This simple system is able to deliver dexamethasone in a controlled manner to solutions used as models for vitreous humor. The proven biocompatibility of laponite as well as its transparency in the gel state, together with the simplicity of the preparation method, makes this system suitable for future in vivo tests of ophthalmic treatment.

Monitoring New Long-Lasting Intravitreal Formulation for Glaucoma with Vitreous Images Using Optical Coherence Tomography

“…A short in vitro study was performed to compare with the results obtained in the in vivo study. A model for vitreous humour (VHM) formed by sodium hialuronate in saline solution was chosen as medium for release, and the procedure was analogous to our precedent study with the DEX/LAP system [23], with equilibration of the BRI/LAP formulation in the VHM for 24 h, centrifugation to separate the liquid phase with the released BRI for analysis and re-suspension of the solid in a new batch of VHM. As can be seen in Figure 8, the released amount was higher in the first extractions, indicating the presence of a fraction of BRI loosely bound to LAP, whereas the released amount in the successive extractions is much lower, corresponding to the BRI fraction more tightly bound to LAP.…”

2D Nanoclay for Biomedical Applications: Regenerative Medicine, Therapeutic Delivery, and Additive Manufacturing

“…The process of intercalating drug molecules within the interlayer space of nanoclay has also been studied for a variety of different small molecules, including dexamethasone, [168] tetracycline, [169] and itraconazole [170] . For example, nanoclay-based hydrogels have shown to entrap glucocorticoid such as dexamethasone to induce bone regeneration in craniofacial defect.…”

Loading of Indocyanine Green within Polydopamine-Coated Laponite Nanodisks for Targeted Cancer Photothermal and Photodynamic Therapy

“…Laponite (Na + 0.7 [(Si 8 Mg 5.5 Li 0.3 )O 20 (OH) 4 ] − 0.7 , LAP) is a kind of synthetic nanoclay with potential applications in biomedical fields due to its specific structure, good biocompatibility and biodegradability [ 24 ]. In the drug delivery field especially, the layered structure of LAP nanodisks (25 nm in diameter and 0.92 nm in thickness) provides sufficient space to encapsulate drug molecules [ 25 ]. In our previous work, the anticancer drug doxorubicin (DOX) was loaded in LAP with a high drug-loading efficiency of 94.3%, and the LAP/DOX nanoparticles formed exhibited more enhanced inhibition effect in cell proliferation than free DOX due to its nanosize [ 24 ].…”