Yeboah Agnes, Cohen Rick I, Faulknor Renea, Schloss Rene, Yarmush Martin L, Berthiaume Francois
Department of Chemical and Biochemical Engineering, Rutgers University, 98 Brett Road, Piscataway, NJ 08854, USA.
Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ 08854, USA.
J Control Release. 2016 Jun 28;232:238-47. doi: 10.1016/j.jconrel.2016.04.020. Epub 2016 Apr 16.
Chronic skin wounds are characterized by poor re-epithelialization, angiogenesis and granulation. Previous work has demonstrated that topical stromal cell-derived growth factor-1 (SDF1) promotes neovascularization, resulting in faster re-epithelialization of skin wounds in diabetic mice. However, the clinical usefulness of such bioactive peptides is limited because they are rapidly degraded in the wound environment due to high levels of proteases. Here, we describe the development of a recombinant fusion protein comprised of SDF1 and an elastin-like peptide that confers the ability to self-assemble into nanoparticles. The fusion protein and recombinant human SDF1 showed similar binding characteristics, as indicated by the measured equilibrium dissociation constant (Kd) for the binding of free SDF1 or the fusion protein to the CXCR4 receptor. The biological activity of SDF1-ELP, as measured by intracellular calcium release in HL60 cells was dose dependent, and also very similar to that of free SDF1. In contrast, the biological activity of SDF1-ELP in vivo was significantly superior to that of free SDF1. When applied to full thickness skin wounds in diabetic mice, wounds treated with SDF1-ELP nanoparticles were 95% closed by day 21, and fully closed by day 28, while wounds treated with free SDF1, ELP alone, or vehicle were only 80% closed by day 21, and took 42days to fully close. In addition, the SDF1-ELP nanoparticles significantly increased the epidermal and dermal layer of the healed wound, as compared to the other groups. These results indicate that SDF1-ELP fusion protein nanoparticles are promising agents for the treatment of chronic skin wounds.
慢性皮肤伤口的特征是上皮再形成、血管生成和肉芽形成不良。先前的研究表明，局部应用基质细胞衍生生长因子-1（SDF1）可促进新血管形成，从而使糖尿病小鼠皮肤伤口的上皮再形成更快。然而，这类生物活性肽的临床实用性有限，因为它们在伤口环境中由于蛋白酶水平高而迅速降解。在此，我们描述了一种重组融合蛋白的开发，该融合蛋白由SDF1和一种赋予自组装成纳米颗粒能力的弹性蛋白样肽组成。融合蛋白和重组人SDF1表现出相似的结合特性，游离SDF1或融合蛋白与CXCR4受体结合的测量平衡解离常数（Kd）表明了这一点。通过HL60细胞内钙释放测量的SDF1-ELP的生物活性是剂量依赖性的，并且也与游离SDF1非常相似。相比之下，SDF1-ELP在体内的生物活性明显优于游离SDF1。当应用于糖尿病小鼠的全层皮肤伤口时，用SDF1-ELP纳米颗粒处理的伤口在第21天95%闭合，在第28天完全闭合，而用游离SDF1、单独的ELP或赋形剂处理的伤口在第21天仅80%闭合，需要42天才能完全闭合。此外，与其他组相比，SDF1-ELP纳米颗粒显著增加了愈合伤口的表皮和真皮层。这些结果表明，SDF1-ELP融合蛋白纳米颗粒是治疗慢性皮肤伤口的有前景的药物。
