Moglia Robert S, Robinson Jennifer L, Muschenborn Andrea D, Touchet Tyler J, Maitland Duncan J, Cosgriff-Hernandez Elizabeth
Department of Biomedical Engineering, Texas A&M University, College Station, Texas, 77843-3120, U.S.A.
Polymer (Guildf). 2014 Jan 14;56(1):426-434. doi: 10.1016/j.polymer.2013.09.009.
Injury caused by trauma, burns, surgery, or disease often results in soft tissue loss leading to impaired function and permanent disfiguration. Tissue engineering aims to overcome the lack of viable donor tissue by fabricating synthetic scaffolds with the requisite properties and bioactive cues to regenerate these tissues. Biomaterial scaffolds designed to match soft tissue modulus and strength should also retain the elastomeric and fatigue-resistant properties of the tissue. Of particular design importance is the interconnected porous structure of the scaffold needed to support tissue growth by facilitating mass transport. Adequate mass transport is especially true for newly implanted scaffolds that lack vasculature to provide nutrient flux. Common scaffold fabrication strategies often utilize toxic solvents and high temperatures or pressures to achieve the desired porosity. In this study, a polymerized medium internal phase emulsion (polyMIPE) is used to generate an injectable graft that cures to a porous foam at body temperature without toxic solvents. These poly(ester urethane urea) scaffolds possess elastomeric properties with tunable compressive moduli (20-200 kPa) and strengths (4-60 kPa) as well as high recovery after the first conditioning cycle (97-99%). The resultant pore architecture was highly interconnected with large voids (0.5-2 mm) from carbon dioxide generation surrounded by water-templated pores (50-300 μm). The ability to modulate both scaffold pore architecture and mechanical properties by altering emulsion chemistry was demonstrated. Permeability and form factor were experimentally measured to determine the effects of polyMIPE composition on pore interconnectivity. Finally, initial human mesenchymal stem cell (hMSC) cytocompatibility testing supported the use of these candidate scaffolds in regenerative applications. Overall, these injectable polyMIPE foams show strong promise as a biomaterial scaffold for soft tissue repair.
由创伤、烧伤、手术或疾病引起的损伤通常会导致软组织缺失，进而导致功能受损和永久性毁容。组织工程旨在通过制造具有必要特性和生物活性线索的合成支架来再生这些组织，从而克服可用供体组织的不足。设计用于匹配软组织模量和强度的生物材料支架还应保留组织的弹性和抗疲劳特性。支架的相互连接的多孔结构对于通过促进物质运输来支持组织生长尤为重要。对于缺乏血管系统以提供营养通量的新植入支架而言，充足的物质运输尤为关键。常见的支架制造策略通常使用有毒溶剂以及高温或高压来实现所需的孔隙率。在本研究中，聚合的中相乳液（polyMIPE）被用于生成一种可注射移植物，该移植物在体温下固化为多孔泡沫，且无需使用有毒溶剂。这些聚（酯脲尿素）支架具有弹性特性，其压缩模量（20 - 200 kPa）和强度（4 - 60 kPa）可调，并且在第一个调节周期后具有高恢复率（97 - 99%）。所得的孔结构高度相互连接，由二氧化碳产生的大孔隙（0.5 - 2 mm）被水模板化孔隙（50 - 300 μm）包围。通过改变乳液化学组成来调节支架孔结构和力学性能的能力得到了证实。通过实验测量渗透率和形状因子以确定polyMIPE组成对孔连通性的影响。最后，初始的人间充质干细胞（hMSC）细胞相容性测试支持了这些候选支架在再生应用中的使用。总体而言，这些可注射的polyMIPE泡沫作为软组织修复的生物材料支架显示出巨大的前景。
