Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280, Plouzané, France.
UMR CNRS 6027, IRDL, Université de Bretagne Occidentale, 29200, Brest, France.
Mar Biotechnol (NY). 2022 Aug;24(4):801-819. doi: 10.1007/s10126-022-10150-y. Epub 2022 Aug 1.
Marine animal by-products of the food industry are a great source of valuable biomolecules. Skins and bones are rich in collagen, a protein with various applications in food, cosmetic, healthcare, and medical industries in its native form or partially hydrolyzed (gelatin). Salmon gelatin is a candidate of interest due to its high biomass production available through salmon consumption, its biodegradability, and its high biocompatibility. However, its low mechanical and thermal properties can be an obstacle for various applications requiring cohesive material. Thus, gelatin modification by cross-linking is necessary. Enzymatic cross-linking by microbial transglutaminase (MTG) is preferred to chemical cross-linking to avoid the formation of potentially cytotoxic residues. In this work, the potential of salmon skin gelatin was investigated, in a comparative study with porcine gelatin, and an enzymatic versus chemical cross-linking analysis. For this purpose, the two cross-linking methods were applied to produce three-dimensional, porous, and mechanically reinforced hydrogels and sponges with different MTG ratios (2%, 5%, and 10% w/w gelatin). Their biochemical, rheological, and structural properties were characterized, as well as the stability of the material, including the degree of syneresis and the water-binding capacity. The results showed that gelatin enzymatically cross-linked produced material with high cross-linking densities over 70% of free amines. The MTG addition seemed to play a crucial role, as shown by the increase in mechanical and thermal resistances with the production of a cohesive material stable above 40 °C for at least 7 days and comparable to porcine and chemically cross-linked gelatins. Two prototypes were obtained with similar thermal resistances but different microstructures and viscoelastic properties, due to different formation dynamics of the covalent network. Considering these results, the enzymatically cross-linked salmon gelatin is a relevant candidate as a biopolymer for the production of matrix for a wide range of biotechnological applications such as food packaging, cosmetic patch, wound healing dressing, or tissue substitute.
海洋动物副产品是有价值生物分子的重要来源。皮肤和骨骼富含胶原蛋白，这种蛋白质在其天然形式或部分水解（明胶）形式下，具有在食品、化妆品、保健和医疗行业的各种应用。由于鲑鱼消费产生的高生物质产量、可生物降解性和高生物相容性，鲑鱼明胶是一种很有前途的候选物。然而，其机械和热性能低可能成为各种需要粘性材料的应用的障碍。因此，需要通过交联来改性明胶。与化学交联相比，微生物转谷氨酰胺酶（MTG）的酶交联更可取，以避免形成潜在的细胞毒性残留物。在这项工作中，鲑鱼皮明胶的潜力在与猪明胶的比较研究中进行了研究，并对酶交联与化学交联进行了分析。为此，将这两种交联方法应用于生产具有不同 MTG 比（明胶的 2%、5%和 10%w/w）的三维多孔机械增强水凝胶和海绵。对其生化、流变和结构特性以及材料的稳定性（包括离浆度和结合水能力）进行了表征。结果表明，酶交联的明胶产生了交联密度超过 70%游离胺的高交联密度材料。MTG 的添加似乎起着至关重要的作用，这表现在机械和热阻力的增加，产生了一种在至少 7 天内稳定在 40°C 以上的粘性材料，与猪明胶和化学交联明胶相当。由于共价网络的形成动力学不同，获得了两种具有相似热阻力但微观结构和粘弹性特性不同的原型。考虑到这些结果，酶交联的鲑鱼明胶是一种相关的生物聚合物候选物，可用于生产各种生物技术应用的基质，例如食品包装、化妆品贴剂、伤口愈合敷料或组织替代物。
