Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
Department of Bioengineering, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
ACS Appl Bio Mater. 2023 Nov 20;6(11):4613-4619. doi: 10.1021/acsabm.3c00378. Epub 2023 Jul 19.
Gelatin hydrogels are used as three-dimensional cell scaffolds and can be prepared using various methods. One widely accepted approach involves crosslinking gelatin amino groups with poly(ethylene glycol) (PEG) modified with -hydroxysuccinimide ester (PEG-NHS). This method enables the encapsulation of live cells within the hydrogels and also facilitates the adhesion of the hydrogel to biological tissues by crosslinking their surface amino groups. Consequently, these hydrogels are valuable tools for immobilizing cells that secrete beneficial substances in vivo. However, the application of gelatin hydrogels is limited due to the requirement for several minutes to solidify under conditions of neutral pH and polymer concentrations suitable for live cells. This limitation makes it impractical for use with biological tissues, which have complex shapes or inclined surfaces, restricting its application to semi-closed spaces. In this study, we propose a tissue-adhesive hydrogel that can be sprayed and immobilized with live cells on biological tissue surfaces. This hydrogel system combines two components: (1) gelatin/PEG-NHS hydrogels and (2) instantaneously solidifying PEG hydrogels. The sprayed hydrogel solidified within 5 s after dispensing while maintaining the adhesive properties of the PEG-NHS component. The resulting hydrogels exhibited protein permeability, and the viability of encapsulated human mesenchymal stem/stromal cells (hMSCs) remained above 90% for at least 7 days. This developed hydrogel system represents a promising approach for immobilizing live cells on tissue surfaces with complex shapes.
明胶水凝胶可用作三维细胞支架，可通过各种方法制备。一种广泛接受的方法是用 -羟基琥珀酰亚胺酯（PEG-NHS）修饰的聚乙二醇（PEG）交联明胶的氨基。这种方法可以将活细胞封装在水凝胶中，并通过交联其表面氨基使水凝胶与生物组织黏附。因此，这些水凝胶是固定在体内分泌有益物质的细胞的有价值的工具。然而，由于在适合活细胞的中性 pH 值和聚合物浓度条件下需要几分钟才能凝固，因此明胶水凝胶的应用受到限制。这一限制使得它不适用于具有复杂形状或倾斜表面的生物组织，限制了其在半封闭空间中的应用。在这项研究中，我们提出了一种可以在生物组织表面喷涂和固定活细胞的组织黏附水凝胶。该水凝胶系统由两部分组成：（1）明胶/PEG-NHS 水凝胶和（2）瞬间凝固的 PEG 水凝胶。喷涂的水凝胶在分配后 5 秒内固化，同时保持 PEG-NHS 成分的黏附性。所得水凝胶表现出蛋白质渗透性，封装的人间充质干细胞/基质细胞（hMSCs）的活力至少在 7 天内保持在 90%以上。这种开发的水凝胶系统代表了一种在具有复杂形状的组织表面固定活细胞的有前途的方法。
