Construction and characterization of adjustable stiffness hydrogels based on gelatin methacryloyl
10.3760/cma.j.cn114453-20240528-00144
- VernacularTitle:基于甲基丙烯酰化明胶的可调刚度水凝胶构建与表征
- Author:
Yanjun FENG
1
;
Xia LIU
;
Haiyue JIANG
Author Information
1. 中国医学科学院北京协和医学院整形外科医院外耳整形再造中心，北京 100144
- Keywords:
Hydrogel;
Stiffness;
Gelatin methacryloyl
- From:
Chinese Journal of Plastic Surgery
2024;40(11):1149-1156
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To construct adjustable stiffness hydrogels based on gelatin methacryloyl (GelMA), in order to better simulate the growth environment under physiological conditions.Methods:SYLGARD 184 silicone rubber was used to prepare adjustable stiffness hydrogels. The stiffness values of the adjustable stiffness hydrogels prepared with GelMA of different grafting rates (30%, 60%, 90%) at various concentrations (5%, 10%, 15%) were quantified using Young’s modulus. Based on the result, the optimal grafting rate GelMA was selected as the material for constructing the adjustable stiffness hydrogels. The relationship between the concentration (2%, 3%, 5%, 6%, 8%, 10%, 15%) of 90% grafting rate (GM90) and the stiffness after photopolymerization was determined by measuring the Young’s modulus of GelMA at different concentrations and fitting the data. Three groups of suitable concentrations were chosen to construct three different stiffness hydrogels. After soaking in phosphate-buffered saline for 48 hours, various samples underwent biomechanical measurements, internal pore structure observation, atomic force microscopy to measure parameters such as Young’s modulus, pore size and surface roughness. Rheological tests were carried out, curves were drawn according to the energy storage modulus and loss modulus, and shear frequencies of the intersection points of the two curves were observed at each concentration to evaluate the ability of hydrogel to maintain its morphology. Data analysis was performed using GraphPad Prism 8.0.2 software. Quantitative data were expressed as Mean±SD, and one-way ANOVA was used for comparison among multiple groups, and LSD method was used for pairwise comparison. Statistical significance was set at P<0.05. Results:Increasing the grafting rate and concentration of GelMA hydrogels effectively enhanced their stiffness. GelMA with a GM90 provided a broader range of stiffness, making it suitable for constructing the adjustable stiffness hydrogels. Fitting curves of GM90 concentrations and stiffness after photopolymerization showed that at concentrations of 2%, 6%, and 15%, GelMA could mimic the stiffness of various tissues of human. Therefore, these three concentrations were selected for subsequent experiments. The Young’s modulus of GM90 at concentrations of 15%, 6% and 2% were (98.43±7.71), (14.57±1.62), and (2.11±0.32) kPa, respectively, with statistically significant differences between each pair of groups ( P<0.01). The pore sizes were (41.32±3.51), (3.26±0.33), and (1.21±0.11) μm, respectively, showing significant differences between each pair of groups ( P<0.01). Surface roughness values were (48.15±2.65), (22.65±1.78), and (24.12±1.43) nm, respectively, with 15% concentration showing significantly higher roughness than the 2% and 6% concentrations ( P<0.01), while there was no significant difference between the 2% and 6% concentrations ( P>0.05). Rheological testing indicated that as the concentration decreased, the shear frequency at the crossover point of the storage modulus and loss modulus of GM90 hydrogels decreased, >100, 30 and 18 Hz, respectively. The result showed that the solid form of GM90 hydrogel with 15% concentration was more stable, while the hydrogel with 2% concentration had better fluidity. Conclusion:Adjusting the grafting rate and concentration can regulate the stiffness of GelMA hydrogels. GelMA hydrogels with a 90% grafting rate provide a wide range of stiffness, making them ideal materials for constructing hydrogels with adjustable stiffness. At concentrations of 2%, 6%, and 15%, GM90 exhibited different mechanical properties and internal structures.
