3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics of University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Zona Industrial da Gandra, Barco, Guimarães, 4805-017, Portugal.
ICVS/3B's - PT Government Associated Laboratory, Braga/, Guimarães, Portugal.
Macromol Biosci. 2021 Apr;21(4):e2000425. doi: 10.1002/mabi.202000425. Epub 2021 Feb 1.
Hydrogels, being capable of mimicking the extracellular matrix composition of tissues, are greatly used as artificial matrices in tissue engineering applications. In this study, the generation of horseradish peroxidase (HRP)-crosslinked silk fibroin (SF) hydrogels, using calcium peroxide as oxidizer is reported. The proposed fast forming calcium-containing SF hydrogels spontaneously undergo SF conformational changes from random coil to β-sheet during time, exhibiting ionic, and pH stimuli responsiveness. In vitro response shows calcium-containing SF hydrogels' encapsulation properties and their ability to promote SaOs-2 tumor cells death after 10 days of culturing, upon complete β-sheet conformation transition. Calcium-containing SF hydrogels' angiogenic potential investigated in an in ovo chick chorioallantoic membrane (CAM) assay, show a high number of converging blood vessels as compared to the negative control, although no endothelial cells infiltration is observed. The in vivo response evaluated in subcutaneous implantation in CD1 and nude NCD1 mice shows that calcium-containing SF hydrogels are stable up to 6 weeks after implantation. However, an increased number of dead cells are also present in the surrounding tissue. The results suggest the potential of calcium-containing SF hydrogels to be used as novel in situ therapeutics for bone cancer treatment applications, particularly to osteosarcoma.
水凝胶能够模拟组织细胞外基质的组成，因此被广泛用作组织工程应用中的人工基质。在这项研究中，报道了使用过氧化钙作为氧化剂生成辣根过氧化物酶（HRP）交联丝素蛋白（SF）水凝胶。所提出的快速形成含钙 SF 水凝胶在时间内会自发地经历 SF 构象从无规卷曲到β-折叠的变化，表现出离子和 pH 刺激响应性。体外反应表明，含钙 SF 水凝胶具有包封性能，并能够在培养 10 天后促进 SaOs-2 肿瘤细胞死亡，此时完全发生了β-折叠构象转变。在鸡胚绒毛尿囊膜（CAM）试验中研究了含钙 SF 水凝胶的血管生成潜力，与阴性对照相比，其汇聚血管的数量较多，尽管没有观察到内皮细胞浸润。在 CD1 和裸鼠 NCD1 皮下植入的体内反应表明，植入后 6 周内含钙 SF 水凝胶是稳定的。然而，周围组织中也存在更多的死亡细胞。这些结果表明，含钙 SF 水凝胶具有作为骨癌治疗应用的新型原位治疗剂的潜力，特别是对骨肉瘤。
