Hamada Yoshitaka, Katoh Shinsuke, Hibino Naohito, Kosaka Hirohumi, Hamada Daisuke, Yasui Natsuo
Department of Orthopedics, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan.
J Hand Surg Am. 2006 Apr;31(4):530-40. doi: 10.1016/j.jhsa.2005.12.003.
We developed a monofilament nylon thread that can release various growth factors to enhance intrinsic reparative processes after flexor tendon injury. We evaluated the properties of this thread in vitro and in vivo.
Nylon threads were coated with gelatin that subsequently was cross-linked in glutaraldehyde. The thread was soaked in basic fibroblast growth factor (bFGF) solution (400 microg/mL). Exogenous bFGF in the thread was released constantly over the course of 1 week. The biologic activity of bFGF and the biomechanical strength of the thread were examined in vitro and its efficacy was investigated in an in vivo rabbit tendon repair model after early flexion exercises. The sutured sites were examined histologically (hematoxylin-eosin, immunohistochemistry, in situ hybridization), biochemically (Western blot test), and biomechanically (ultimate load) after surgery.
This gelatin-coated thread absorbed iodine 125-labeled bFGF in a time-dependent manner. The total amount of bFGF absorbed by the thread within the tendon tissue was between 3 and 15 mug depending on the concentration of bFGF solution. Basic fibroblast growth factor protein was delivered selectively-not in the surrounding scar but in the repaired tendon-for 3 weeks. Histologic analysis showed that the cellular density at the repaired site increased in accordance with the expression of bFGF messenger RNA and protein in the tendon. Endogenous bFGF expression seemed to be enhanced transiently by exogenous bFGF during the first few weeks. The epitenon showed a vigorous fibroblastic response to the coated thread and the ultimate load also was increased significantly at 3 weeks after surgery.
This bFGF-coated nylon suture gave excellent results in delivering a drug selectively to tendon; it also induced an increase of biomechanical strength and a thickening of the epitenon layer in vivo during a 3-week period, thereby accelerating cellular proliferation, initially peripherally and later centrally. This system may become a therapeutic tool to be used in hand surgery.
我们研发了一种单丝尼龙线，其能够释放多种生长因子，以增强屈肌腱损伤后的内在修复过程。我们在体外和体内评估了这种线的特性。
尼龙线用明胶包被，随后在戊二醛中交联。将线浸泡在碱性成纤维细胞生长因子（bFGF）溶液（400微克/毫升）中。线中的外源性bFGF在1周的时间内持续释放。在体外检测bFGF的生物活性和线的生物力学强度，并在早期进行屈曲练习后的体内兔肌腱修复模型中研究其疗效。术后对缝合部位进行组织学（苏木精-伊红染色、免疫组织化学、原位杂交）、生化（蛋白质印迹试验）和生物力学（极限负荷）检查。
这种明胶包被的线以时间依赖性方式吸收碘125标记的bFGF。根据bFGF溶液的浓度，肌腱组织中线吸收的bFGF总量在3至15微克之间。碱性成纤维细胞生长因子蛋白在3周内选择性地传递至修复的肌腱而非周围瘢痕中。组织学分析表明，修复部位的细胞密度随着肌腱中bFGF信使核糖核酸和蛋白的表达而增加。在最初几周，外源性bFGF似乎短暂增强了内源性bFGF的表达。腱外膜对包被的线表现出强烈的成纤维细胞反应，并且在术后3周极限负荷也显著增加。
这种bFGF包被的尼龙缝线在将药物选择性地递送至肌腱方面取得了优异的效果；它还在3周内诱导体内生物力学强度增加和腱外膜层增厚，从而加速细胞增殖，最初是外周增殖，随后是中央增殖。该系统可能成为手外科手术中使用的一种治疗工具。
