Comparison of the mucoadhesive properties of thiolated polyacrylic acid to thiolated polyallylamine

Light-controllable viscoelastic properties of a photolabile carboxybetaine ester-based polymer with mucus and cellulose sulfate

“…1. The obtained results were comparable to those observed for common mucus-CBE polymer systems based on poly(acrylic) acid [56,57].…”

“…Through investigation of the viscoelastic properties, the interactions of polymer-based samples with both mucus and cellulose sulfate substrates were evaluated. The rheological synergism was in the same range as that with polyallylamine acid [56] or other systems based on chitosan [57]. Moreover, the viscoelastic properties can be modulated, and the interactions with both substrates were suppressed by UV light due to presence of the photolyzable ester group in CBE, which makes this approach more attractive.…”

“…As can be seen, ΔG′/G′ becomes higher with increasing polymer content and exhibits rheological synergism above a concentration of 1 wt.%. Furthermore, above a sample of concentration of 4 wt.%, ΔG′/G′ rapidly increases from 0.2 to 4; this increase is connected to the critical polymer concentration in the systems, which provides significantly enhanced interactions of the polymer chains with mucus compared with those observed for other polymer systems, such as polyallylamine [56] and chitosan-based [57] systems and decreased interactions compared with those of polyacrylic acid [58]. For the sample consisting of the photolyzed polymer, ΔG´/G´slightly increases with the polymer content.…”

2,2′Dithiodinicotinyl ligands: Key to more reactive thiomers

“…Duggan et al made the same observation regarding the different texture between thiolated and unmodified test disks. While thiolated PAA samples remained a solid tablet, unmodified samples turned completely into a jelly mass (Duggan et al, 2016b). As the tablets are applied directly on the mucosa, the enhanced mucoadhesion is in this experimental setup most likely primarily based on the higher activity of thiol groups due to double preactivation and on the changed swelling behavior, whereas the stability towards oxidation is of minor importance.…”

Nanoparticles Loaded Thermoresponsive In Situ Gel for Ocular Antibiotic Delivery against Bacterial Keratitis

“…Recently, biopolymer-based NPs have gained in popularity and interest due to their unique enhanced bioavailability, biodegradability, and sustained release effects in ophthalmic drug delivery [ 31 ]. Gelatin is one of the most widely used natural biopolymers due to its easy and low-cost availability, the presence of large active groups, mucoadhesion, biocompatibility, and biodegradable nature [ 32 , 33 , 34 , 35 , 36 ]. However, the problem with gelatin-based NPs is their need to use cross linkers [ 31 , 32 ], which usually have the potential for reactivity and toxicity [ 37 ].…”