Infiltration of laponite: An effective approach to improve the mechanical properties and thermostability of collagen hydrogel

Abstract

Rapid aggregate precipitation of collagen and laponite in solution restricted the development of corresponding hybrid materials. Herein, a facile method of immerging collagen hydrogel into laponite dispersion was adopted to prepare hybrid collagen/laponite hydrogel, avoiding the precipitation. Collagen hydrogel shrunk and water content decreased dramatically after laponite solution treatment. According to the images of Scanning electron microscopy and energy dispersive system, the uniformly dispersed laponite in collagen hydrogel was observed, demonstrating infiltration of laponite into collagen hydrogel. X-ray photoelectron spectroscopy results revealed that coordination bonds generated between magnesium in laponite and collagen. Thermogravimetric analysis and Differential scanning calorimetry results displayed thermal decomposition temperature of collagen hydrogel increased from 321 to 342 C, and denaturation temperature rose from 43.8 to 50.8 C after laponite infiltration. Rheological and compressive tests showed the elastic modulus, fracture stress, compressive modulus and rupture point of hydrogel treated by 10% laponite were 695.2 Pa, 253.3 kPa, 13.5 kPa and 76.7%, respectively, which were about 3.5, 5.5, 45.0, and 1.4 times larger than those of pristine collagen hydrogel. Besides, enzyme degraded rate of collagen was decelerated, and the hydrogel was still nontoxic with the infiltration of laponite. The promising data demonstrated infiltration of laponite was an effective way to fabricate collagen/laponite hybrid materials with desirable properties.

Fluorescent assay for acetylcholinesterase activity and inhibitor screening based on lanthanide organic/inorganic hybrid materials

“…As shown in Fig. 1c, the FTIR spectra of Lap as well as Eu(DPA) 3 @Lap show the signals centered at 3436 and 1007 cm −1 , which could be assigned to the -OH bending vibration and -Si-Ostretching vibration, respectively, 21 demonstrating the presence of Lap in our material. The FTIR spectrum of Eu(DPA) 3 @Lap lacks the characteristic absorbance of DPA at 1700 cm −1 , which is attributed to the -COOH group stretching vibration, indicating the successful coordination between the -COOH group and Eu.…”

Collagen-Laponite Nanoclay Hydrogels for Tumor Spheroid Growth

“…In agreement with our results, Li et al showed the enhancement of mechanical properties of a 5 mg/mL cattle skin collagen hydrogel at different Laponite concentration addition. They showed that the elastic modulus, fracture stress, compression modulus, and rupture point of hydrogel treated by 10% LapNC were 695.2 Pa, 253.3 kPa, 13.5 kPa, and 76.7%, respectively, which were about 3.5, 5.5, 45.0, and 1.4 times larger than those of regular collagen-based hydrogel …”

“…They showed that the elastic modulus, fracture stress, compression modulus, and rupture point of hydrogel treated by 10% LapNC were 695.2 Pa, 253.3 kPa, 13.5 kPa, and 76.7%, respectively, which were about 3.5, 5.5, 45.0, and 1.4 times larger than those of regular collagen-based hydrogel. 36 …”

“…They showed that the elastic modulus, fracture stress, compression modulus, and rupture point of hydrogel treated by 10% LapNC were 695.2 Pa, 253.3 kPa, 13.5 kPa, and 76.7%, respectively, which were about 3.5, 5.5, 45.0, and 1.4 times larger than those of regular collagen-based hydrogel. 36 This enhancement of mechanical properties due to the addition of nanoclays to the hydrogel could be used for different purposes. For instance, to promote osteogenic differentiation of mesenchymal stem cells in vitro, it has been reported that human bone marrow stem cells seeded onto surfaces coated with air-dried Laponite films (2.5 mg/mL) possess a higher osteogenic capacity at week 3.…”

Laponite-Based Nanocomposite Hydrogels for Drug Delivery Applications

“…Becher et al showed IC50 values of approximately 0.5–1.5 mg/mL Laponite when incubated with HeLa or MCF-7 cells [ 88 ]. Li et al reported Laponite concentrations of up to 10% w / v (100 mg/mL) showed insignificant changes in the cellular viability of pre-osteoblastic MC3T3-E1 cells [ 89 ]. Therefore, the range of IC50 values of Laponite varies rather considerably.…”