Enhanced mechanical and cell adhesive properties of photo-crosslinked PEG hydrogels by incorporation of gelatin in the networks

Abstract

Although synthetic polymers may have suitable physicochemical properties for biomedical applications, biological properties are generally lacking. Poly(ethylene glycol) (PEG) is a frequently used polymer for the preparation of hydrogels. Due to its hydrophilic character, however, cellular interactions with PEG hydrogels are minimal or absent. To improve the cell adhesive properties of PEG hydrogels, we developed hybrid hydrogels based on PEG and the natural polymer gelatin. PEG dimethacrylate (PEG-dMA) and gelatin methacrylate (GelMA) macromers were prepared, which were photo-crosslinked in water in different ratios (75:25, 50:50 and 25:75 % (v/v)). The obtained hybrid networks showed macrophase separation, which could be prevented by photo-crosslinking in 0.5 % (v/v) acetic acid in water. The toughness of 50:50 % PEG-dMA:GelMA hydrogels prepared in 0.5 % acetic acid was 2.5 times higher than that of single polymer hydrogels made of PEG-dMA or GelMA. Hybrid hydrogels crosslinked in 0.5 % acetic acid supported the proliferation of human mesenchymal stem cells to the same extent as compared to 100 % gelatin hydrogel, whereas the cells did not proliferate on 100 % PEG hydrogel. In conclusion, our results show that both the cell adhesive and mechanical properties of a photocrosslinked PEG network can be improved by incorporation of gelatin in the network.

Expanding and optimizing 3D bioprinting capabilities using complementary network bioinks

“…In the cases of thiol-ene reaction bioinks (GelAGE, HANB, and PEGNB), dithiothreitol (DTT) was included as a crosslinker. For PEG-based bioink preparation, a minimal amount of acetic acid was introduced to avoid phase separation when mixing with 5 wt % gelatin, a protocol adapted from the literature ( 41 ). At neutral pH, aqueous mixtures of gelatin and PEG will form a liquid-liquid phase-separated system when the critical concentration of either gelatin or PEG is exceeded.…”

Attenuating Fibrotic Markers of Patient-Derived Dermal Fibroblasts by Thiolated Lignin Composites

“…As shown in Figure 3a, viscosities of fGel were 0.6 Pa•s (40 mg/mL) and 3.2 Pa•s (200 mg/mL), while those of fGelMA were 0.5 Pa•s (40 mg/mL) and 1.14 Pa•s (200 mg/mL) at room temperatures. Due to such low viscosity at room temperature, we were able to form composites including gelatin without adding acetic acid 52 or heating 53 in the cases of applying porcine gelatin. As shown in Figure S3 (Supplementary Information), the viscosity of porcine GelMA (180 mg/mL) was several orders of magnitude higher than that of fGelMA (200 mg/mL).…”

Attenuating Fibrotic Markers of Patient-Derived Dermal Fibroblasts by Thiolated Lignin Composites

“…As shown in Figure 3 a, viscosities of fGel were 0.6 Pa s (40 mg/mL) and 3.2 Pa s (200 mg/mL), whereas those of fGelMA were 0.5 Pa s (40 mg/mL) and 1.14 Pa s (200 mg/mL) at room temperature. Because of such low viscosity at room temperature, we were able to form composites including gelatin without adding acetic acid 32 or heating 33 in the cases of applying porcine gelatin. As shown in Figure S5 , the viscosity of porcine GelMA (pGelMA, 180 mg/mL) was several orders of magnitude higher than that of fGelMA (200 mg/mL).…”