Preparation of Poly(acrylic acid) Hydrogel by Radiation Crosslinking and Its Application for Mucoadhesives

Abstract

Abstract:A mucoadhesive drug delivery system can improve the effectiveness of a drug by maintaining the drug concentration and allowing targeting and localization of the drug at a specific site. Acrylic-based hydrogels have been used extensively as a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, poly(acrylic acid) was selected to prepare the bioadhesive hydrogel adhering to mucosal surfaces using a radiation process. Poly(acrylic acid) was dissolved in water to a prepare poly(acrylic acid) solution, and the solution was then irradiated by an electron beam at up to 75 kGy to make hydrogels. Their physical properties, such as gel percent, swelling percent and adhesive strength to mucosal surfaces, were investigated. Triamcinolone acetonide was used as a model drug. The dried poly(acrylic acid) film was dipped in a 0.1 wt% triamcinolone acetonide solution in ethanol, and then dried at 25 °C. The release of triamcinolone acetonide was determined at different time intervals, and UV (Ultraviolet)-Vis spectroscopy was used to determine the released concentration of triamcinolone acetonide at 238 nm. It was shown that poly(acrylic acid)-based drug carriers were successfully prepared for use in a bioadhesive drug delivery system.

Detailed mechanism of aniline nucleation into more conductive nanofibers

“…6. This was in agreement with previous study [39] which resulted the higher concentration of AA decreases swelling degree due to stronger crosslinking yield. In our knowledge, the stronger À ÀCOOHÁ Á ÁHOOCÀ À bonding between PAA chains leads to lower wettability.…”

“…In our knowledge, the stronger À ÀCOOHÁ Á ÁHOOCÀ À bonding between PAA chains leads to lower wettability. However, the less flexibility of PAA chains was reported as the main reason of lower swelling [39]. In gradient pH, as acidity decreases, electrostatic repulsion between carboxylic groups enhances due to lower H+ concentration and higher number of charged carboxylate terminates.…”

A macrophage/fibroblast co-culture system using a cell migration chamber to study inflammatory effects of biomaterials

“…Data represent mean ± SD, n P 3, ⁄ p < 0.05. sessed the highest and lowest potential to induce inflammatory responses, respectively. These findings suggest that the hydrophilic/anionic COOH groups represent a low pro-inflammatory potential, which is also supported by the use of hydrogel-based coatings composed of poly(acrylic acid), developed to modulate events associated with inflammation after implantation [75][76][77][78], or hydrophilic/anionic hydrogel coatings that significantly reduced the tissue responses in drug delivery and neural electrode applications [77,79,80]. More important, however, is the obvious advantage of the co-culture system of macrophages and fibroblasts presented here to mimic autocrine, paracrine and juxtacrine signals exchange during biomaterial contact in one system.…”

Single-step process to improve the mechanical properties of carbon nanotube yarn

“…The radiolysis of water molecules present in the system plays an important role in the crosslinking process. The hydroxyl radicals originating from the water attack the polymer chain grafted on the CNT yarn walls, resulting in the formation of radicals, which will form crosslinks between the polymer molecules [42]. …”

“…The improved mechanical properties are attributed to formation of crosslinks among the polymer grafted onto the surface. The PAA can form crosslinks by anhydride formation [42]. In an acid solution, the recombination process becomes very fast and crosslinking dominates over scission.…”