Wound Biology Group, Cardiff Institute of Tissue Engineering and Repair, Tissue Engineering and Reparative Dentistry, School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, UK.
Mol Pharm. 2010 Jun 7;7(3):699-707. doi: 10.1021/mp9002656.
We recently developed a bioresponsive dextrin-recombinant human epidermal growth factor (rhEGF) conjugate as a polymer therapeutic with potential for use in the promotion of tissue repair. The aim of these studies was to use patient-derived wound fluid and fibroblasts to evaluate its potential for further development as a treatment for chronic wounds, such as venous leg ulceration, a growing clinical challenge in the aging population. First, the levels of EGF (ELISA assay), alpha-amylase and elastase (enzyme assays) were measured in patient-derived acute and chronic wound fluid. EGF was detected in acute, but not in chronic wound fluid. alpha-Amylase concentrations were higher in acute (188 IU/L), compared to chronic wound fluid (52 IU/L), but both were in the range of human serum levels. Although elastase was present in chronic wound fluid (2.1 +/- 1.2 RFU/min), none was detected in acute wound fluid. Dextrin-rhEGF incubation in chronic wound fluid led to endogenous alpha-amylase-mediated release of rhEGF (ELISA) that was maximal at 48 h. When the migration of HaCaT keratinocytes and of human fibroblasts (isolated from patient-matched, normal skin and chronic dermal wounds) was studied in vitro using the scratch wound assay, enhanced cell migration was observed in response to both free rhEGF and alpha-amylase-activated dextrin-rhEGF conjugate compared to controls. In addition, fibroblasts displayed increased proliferation (normal dermal fibroblasts approximately 160%; chronic wound fibroblasts approximately 140%) following incubation (72 h) with dextrin-rhEGF that had been exposed to physiological levels of alpha-amylase (93 IU/L). These results suggest further preclinical in vivo evaluation of dextrin-rhEGF is warranted to determine whether conjugate pharmacokinetics and rhEGF liberation into such a complex and aggressive environment can still lead to bioactivity.
我们最近开发了一种响应生物的糊精-重组人表皮生长因子（rhEGF）缀合物，作为一种聚合物治疗剂，具有促进组织修复的潜力。这些研究的目的是使用患者来源的伤口液和成纤维细胞来评估其作为治疗慢性伤口（如静脉性腿部溃疡）的进一步开发潜力，静脉性腿部溃疡是老龄化人口中日益严重的临床挑战。首先，使用酶联免疫吸附测定（ELISA 测定）测量患者来源的急性和慢性伤口液中的 EGF（表皮生长因子）、α-淀粉酶和弹性蛋白酶（酶测定）水平。在急性伤口液中检测到 EGF，但在慢性伤口液中未检测到。与慢性伤口液（52 IU/L）相比，急性伤口液中α-淀粉酶浓度更高（188 IU/L），但均在人血清水平范围内。尽管弹性蛋白酶存在于慢性伤口液中（2.1 +/- 1.2 RFU/min），但在急性伤口液中未检测到。糊精-rhEGF 在慢性伤口液中的孵育导致内源性α-淀粉酶介导的 rhEGF 释放（ELISA），在 48 小时达到最大值。当使用划痕伤口测定法在体外研究 HaCaT 角质形成细胞和人成纤维细胞（从患者匹配的正常皮肤和慢性皮肤伤口中分离）的迁移时，与对照相比，观察到游离 rhEGF 和α-淀粉酶激活的糊精-rhEGF 缀合物均能增强细胞迁移。此外，与对照相比，孵育（72 小时）暴露于生理水平α-淀粉酶（93 IU/L）的糊精-rhEGF 的成纤维细胞显示出增殖增加（正常真皮成纤维细胞约增加 160%；慢性伤口成纤维细胞约增加 140%）。这些结果表明，需要进一步进行体内药代动力学研究和 rhEGF 释放到这种复杂和侵袭性环境中的研究，以确定缀合物的药代动力学和 rhEGF 释放是否仍能导致生物活性。
