States of water, surface and rheological characterisation of a new biohydrogel as articular cartilage substitute

Abstract

PVA based hydrogel was synthesised using, as crosslinking agent, trisodium trimetaphosphate (STMP) and its morphology was modified inducing a microporous structure to obtain potential substitutes for cartilage tissue. The hydrogel was characterised by Infrared Spectroscopy combined with Time of flight mass spectrometry (ToF-SIMS) that confirmed the successful occurrence of crosslinking reaction, the hyphotised crosslinking arm and its homogeneous distribution. The mechanical spectra of the fully hydrated samples confirmed covalently crosslinked systems with a rheological behaviour similar to that of tibial cartilage. Further analysis in terms of water content measurements, thermal stability and cytotoxicity confirmed the applicability of such a hydrogel as cartilage substitute

Biodegradable, anti‐adhesive and tough polyurethane hydrogels crosslinked by triol crosslinkers

“…The storage modulus (G′), loss modulus (G″) and phase angle of PU hydrogels are analyzed as a function of frequency at 37°C. As shown in Figure a, G′ and G″ of all hydrogels are on the same order of magnitude respectively, and G′ is always one order of magnitude higher than G″ of each sample, indicating that all the hydrogels show strong “gel‐like” elastic behavior (Leone, Bidini, Lamponi, & Magnani, ). G′ remains in a certain constant range with the increase of frequency, which indicates stability and structural integrity of each crosslinked hydrogel.…”

Efficacy of collagen and alginate hydrogels for the prevention of rat chondrocyte dedifferentiation

“…They can mimic the native extracellular matrix with compositional and mechanical similarity to cartilage. 25 , 26 The rheological behavior of cell-free hydrogels, as examined by a dynamic mechanical analyzer, revealed that the moderate range of E′ of Alg/Col gel (90 kPa) being similar to that of tibia cartilage (30 ~ 110 kPa) 27 may be favorable for cells to sense and secrete cartilaginous matrix.…”

Continuous multilayered composite hydrogel as osteochondral substitute

“…The reaction mixture was stirred for 2 h. The obtained hydrogel was then layered into a petri dish and the obtained soft film (first layer) was rinsed with large volumes of distilled water until no weight loss could be detected. 11,12 The best nHA/PVA molar ratio was identified through rheological analysis. The sample with the lowest ratio (nHA/PVA 0.010) showed poor rheological properties for the foreseen application.…”

“…Water content. As previously described, 12 the three regimes into which water can be distinguished, namely non-freezing water, bound-freezing water and freezing water (or bulk water) were quantified by DSC. 15 The weight of completely swollen hydrogels (WSG) and the total weight of water inside the network (WH) were detected by TGA.…”

“…The comparison of the termographs of all the hydrogels, reported in Figure 4, highlights a general trend: all the crosslinked matrices showed a lower degree of crystallinity with respect to the native polymer. The treatment to which the polymer is subjected during the crosslinking process, as already reported, 12 drastically decreases the crystallinity due to the breakdown of the pre-established chains order. Accordingly, the PS21 layer shows a very low degree of crystallinity.…”