Watarai Akira, Schirmer Lucas, Thönes Stephan, Freudenberg Uwe, Werner Carsten, Simon Jan C, Anderegg Ulf
Department of Dermatology, Venereology and Allergology, Leipzig University, Germany; Department of Dermatology, Kitasato University School of Medicine, Japan.
Leibniz Institute of Polymer Research, Technical University of Dresden, Germany.
Acta Biomater. 2015 Oct;25:65-75. doi: 10.1016/j.actbio.2015.07.036. Epub 2015 Jul 26.
Hydrogels are promising biomaterials that can adapt easily to complex tissue entities. Furthermore, chemical modifications enable these hydrogels to become an instructive biomaterial to a variety of cell types. Human dermal fibroblasts play a pivotal role during wound healing, especially for the synthesis of novel dermal tissue replacing the primary fibrin clot. Thus, the control of growth and differentiation of dermal fibroblasts is important to modulate wound healing. In here, we utilized a versatile starPEG-heparin hydrogel platform that can be independently adjusted with respect to mechanical and biochemical properties for cultivating human dermal fibroblasts. Cell-based remodeling of the artificial matrix was ensured by using matrix metalloprotease (MMP) cleavable crosslinker peptides. Attachment and proliferation of fibroblasts on starPEG-heparin hydrogels of differing stiffness, density of pro-adhesive RGD peptides and MMP cleavable peptide linkers were tested. Binding and release of human TGFβ1 as well as biological effect of the pre-adsorbed growth factor on fibroblast gene expression and myofibroblast differentiation were investigated. Hydrogels containing RGD peptides supported fibroblast attachment, spreading, proliferation matrix deposition and remodeling compared to hydrogels without any modifications. Reversibly conjugated TGFβ1 was demonstrated to be constantly released from starPEG-heparin hydrogels for several days and capable of inducing myofibroblast differentiation of fibroblasts as determined by induction of collagen type I, ED-A-Fibronectin expression and incorporation of alpha smooth muscle actin and palladin into F-actin stress fibers. Taken together, customized starPEG-heparin hydrogels could be of value to promote dermal wound healing by stimulating growth and differentiation of human dermal fibroblasts.
The increasing number of people of advanced age within the population results in an increasing demand for the treatment of non-healing wounds. Hydrogels are promising biomaterials for the temporary closure of large tissue defects: They can adapt to complex tissue geometry and can be engineered for specific tissue needs. We used a starPEG-heparin hydrogel platform that can be independently adjusted to mechanical and biochemical characteristics. We investigated how these hydrogels can support attachment, proliferation and differentiation of dermal fibroblasts. After introducing adhesive peptides these hydrogels support cell attachment and proliferation. Moreover, TGFβ - an essential growth and differentiation factor for fibroblasts - can be immobilized reversibly and functionally on these hydrogels. Thus, starPEG-heparin hydrogels could be developed to bioactive temporary wound dressings.
水凝胶是很有前景的生物材料，能够轻松适应复杂的组织实体。此外，化学修饰能使这些水凝胶成为针对多种细胞类型的具有指导作用的生物材料。人皮肤成纤维细胞在伤口愈合过程中起关键作用，尤其是在合成替代最初纤维蛋白凝块的新型真皮组织方面。因此，控制皮肤成纤维细胞的生长和分化对于调节伤口愈合很重要。在此，我们利用了一种通用的星型聚乙二醇-肝素水凝胶平台，该平台可在机械和生化特性方面独立调节，用于培养人皮肤成纤维细胞。通过使用基质金属蛋白酶（MMP）可裂解的交联肽确保了人工基质基于细胞的重塑。测试了成纤维细胞在不同硬度、促黏附RGD肽密度和MMP可裂解肽连接体的星型聚乙二醇-肝素水凝胶上的附着和增殖情况。研究了人转化生长因子β1（TGFβ1）的结合与释放以及预吸附的生长因子对成纤维细胞基因表达和肌成纤维细胞分化的生物学效应。与未作任何修饰的水凝胶相比，含有RGD肽的水凝胶支持成纤维细胞的附着、铺展、增殖、基质沉积和重塑。经证实，可逆结合的TGFβ1可从星型聚乙二醇-肝素水凝胶中持续释放数天，并能够通过诱导I型胶原蛋白、ED-A-纤连蛋白表达以及将α平滑肌肌动蛋白和帕拉丁掺入F-肌动蛋白应力纤维来诱导成纤维细胞向肌成纤维细胞分化。综上所述，定制的星型聚乙二醇-肝素水凝胶通过刺激人皮肤成纤维细胞的生长和分化，可能对促进真皮伤口愈合具有重要价值。
人口中高龄人群数量的增加导致对不愈合伤口治疗的需求不断增长。水凝胶是用于临时封闭大组织缺损的很有前景的生物材料：它们能适应复杂的组织几何形状，并且可以根据特定组织需求进行设计。我们使用了一种可在机械和生化特性方面独立调节的星型聚乙二醇-肝素水凝胶平台。我们研究了这些水凝胶如何支持皮肤成纤维细胞的附着、增殖和分化。引入黏附肽后，这些水凝胶支持细胞附着和增殖。此外，TGFβ（成纤维细胞重要的生长和分化因子）可以可逆且功能性地固定在这些水凝胶上。因此，星型聚乙二醇-肝素水凝胶可被开发成生物活性临时伤口敷料。
