De Maeseneer Tess, Van Damme Lana, Aktan Merve Kübra, Braem Annabel, Moldenaers Paula, Van Vlierberghe Sandra, Cardinaels Ruth
Soft Matter, Rheology and Technology, Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200J Box 2424, 3001 Leuven, Belgium.
Polymer Chemistry & Biomaterials Group, Centre of Macromolecular Chemistry, Department of Organic and Macromolecular Chemistry, Ghent University (UGent), Krijgslaan 281, S4-Bis, 9000 Ghent, Belgium.
Gels. 2024 Feb 26;10(3):167. doi: 10.3390/gels10030167.
The tissue engineering field is currently advancing towards minimally invasive procedures to reconstruct soft tissue defects. In this regard, injectable hydrogels are viewed as excellent scaffold candidates to support and promote the growth of encapsulated cells. Cross-linked gelatin methacryloyl (GelMA) gels have received substantial attention due to their extracellular matrix-mimicking properties. In particular, GelMA microgels were recently identified as interesting scaffold materials since the pores in between the microgel particles allow good cell movement and nutrient diffusion. The current work reports on a novel microgel preparation procedure in which a bulk GelMA hydrogel is ground into powder particles. These particles can be easily transformed into a microgel by swelling them in a suitable solvent. The rheological properties of the microgel are independent of the particle size and remain stable at body temperature, with only a minor reversible reduction in elastic modulus correlated to the unfolding of physical cross-links at elevated temperatures. Salts reduce the elastic modulus of the microgel network due to a deswelling of the particles, in addition to triple helix denaturation. The microgels are suited for clinical use, as proven by their excellent cytocompatibility. The latter is confirmed by the superior proliferation of encapsulated adipose tissue-derived stem cells in the microgel compared to the bulk hydrogel. Moreover, microgels made from the smallest particles are easily injected through a 20G needle, allowing a minimally invasive delivery. Hence, the current work reveals that powdered cross-linked GelMA is an excellent candidate to serve as an injectable hydrogel for adipose tissue engineering.
组织工程领域目前正朝着采用微创手术来修复软组织缺损的方向发展。在这方面，可注射水凝胶被视为支持和促进包封细胞生长的理想支架候选材料。交联甲基丙烯酸明胶（GelMA）水凝胶因其模仿细胞外基质的特性而受到广泛关注。特别是，GelMA微凝胶最近被认为是有趣的支架材料，因为微凝胶颗粒之间的孔隙有利于细胞移动和营养物质扩散。目前的工作报道了一种新型的微凝胶制备方法，即将块状GelMA水凝胶研磨成粉末颗粒。通过在合适的溶剂中溶胀，这些颗粒可以很容易地转化为微凝胶。微凝胶的流变特性与粒径无关，并且在体温下保持稳定，仅在高温下弹性模量有轻微的可逆降低，这与物理交联的展开有关。除了三螺旋变性外，盐还会由于颗粒的去溶胀而降低微凝胶网络的弹性模量。微凝胶具有优异的细胞相容性，证明其适用于临床应用。与块状水凝胶相比，微凝胶中包封的脂肪组织来源干细胞的增殖优势证实了这一点。此外，由最小颗粒制成的微凝胶很容易通过20G针头注射，实现微创给药。因此，目前的工作表明，粉末状交联GelMA是用于脂肪组织工程的可注射水凝胶的理想候选材料。
