Swelling characteristics and biocompatibility of ionic liquid based hydrogels for biomedical applications

Abstract

Polymers are commonly used in medical device manufacturing, e.g. for drug delivery systems, bone substitutes and stent coatings. Especially hydrogels exhibit very promising properties in this field. Hence, the development of new hydrogel systems for customized application is of great interest, especially regarding the swelling behavior and mechanical properties as well as the biocompatibility. The aim of this work was the preparation and investigation of various polyelectrolyte and poly-ionic liquid based hydrogels accessible by radical polymerization. The obtained polymers were covalently crosslinked with N,N'-methylenebisacrylamide (MBAA) or different lengths of poly(ethyleneglycol)diacrylate (PEGDA). The effect of different crosslinker-to-monomer ratios has been examined. In addition to the compression curves and the maximum degree of swelling, the biocompatibility with L929 mouse fibroblasts of these materials was determined in direct cell seeding experiments and the outcome for the different hydrogels was compared.

Ion Exchange Controlled Drug Release from Polymerized Ionic Liquids

“…[23] In addition, the high water content and their physicochemical similarity to extracellular matrix are often a reasons for the outstanding biocompatibility of hydrogels. [15,23] This can be reflected in the successful in vivo use or the amount of studies in vitro in several applications, for example their use in the peritoneum or as artificial tissue for balloon catheter. [24,25] Hydrogels are also tunable in their deformability, have a high load tolerance, and can even adapt to the applied surface.…”

“…The MAESO 3 and MAETMA hydrogels were synthesized by radical polymerization as previously described by our group. [15] In brief, the monomer and the corresponding amount of the crosslinker N,N′-methylenebis(acrylamide) (MBAA) (2 mol%) were dissolved in deionized water (DW), to adjust the total monomer concentration to the required value (2 mol L −1 ). Subsequently, APS solution was added (0.1 mol%).…”

“…In one of our previous works we already examined the mechanical properties of hydrogels not being sterilized. [15] These values were used for a comparison with sterilized hydrogels. The comparison of stress-strain curves of polyMAESO 3 with MBAA and poly(ethylene glycol) diacrylate (PEGDA 250) is presented in Figure 7a comparing a crosslinker being not sterilized versus being sterilized.…”

“…Furthermore, the hydrogels presented proved to be mechanically deformable paired with a certain mechanical resilience, which is promising regarding an optimal distribution in complex cavities. [15] In our work, we focus on a possible application example for the treatment of glaucoma since this disease is of great social relevance. Furthermore, the site of action is easily accessible for minimal invasive surgeries.…”

“…[10,11] Some remarkable hydrogel characteristics are, for instance, stimulus sensitivity, swelling capability, antimicrobial activity, high biocompatibility, resistance to rheological stress even up to self-healing capabilities and many more. [12][13][14][15] Furthermore, hydrogels impress by dint of various synthesizable physical forms, including…”