Ifkovits Jamie L, Padera Robert F, Burdick Jason A
Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
Biomed Mater. 2008 Sep;3(3):034104. doi: 10.1088/1748-6041/3/3/034104. Epub 2008 Aug 8.
The development of biodegradable materials with elastomeric properties is beneficial for a variety of applications, including for use in the engineering of soft tissues. Although others have developed biodegradable elastomers, they are restricted by their processing at high temperatures and under vacuum, which limits their fabrication into complex scaffolds. To overcome this, we have modified precursors to a tough biodegradable elastomer, poly(glycerol sebacate) (PGS) with acrylates to impart control over the crosslinking process and allow for more processing options. The acrylated-PGS (Acr-PGS) macromers are capable of crosslinking through free radical initiation mechanisms (e.g., redox and photo-initiated polymerizations). Alterations in the molecular weight and % acrylation of the Acr-PGS led to changes in formed network mechanical properties. In general, Young's modulus increased with % acrylation and the % strain at break increased with molecular weight when the % acrylation was held constant. Based on the mechanical properties, one macromer was further investigated for in vitro and in vivo degradation and biocompatibility. A mild to moderate inflammatory response typical of implantable biodegradable polymers was observed, even when formed as an injectable system with redox initiation. Moreover, fibrous scaffolds of Acr-PGS and a carrier polymer, poly(ethylene oxide), were prepared via an electrospinning and photopolymerization technique and the fiber morphology was dependent on the ratio of these components. This system provides biodegradable polymers with tunable properties and enhanced processing capabilities towards the advancement of approaches in engineering soft tissues.
具有弹性特性的可生物降解材料的开发有利于多种应用,包括用于软组织工程。尽管其他人已经开发出可生物降解的弹性体,但它们受到高温和真空处理的限制,这限制了它们制成复杂的支架。为了克服这一问题,我们用丙烯酸酯对一种坚韧的可生物降解弹性体聚(癸二酸甘油酯)(PGS)的前体进行了改性,以控制交联过程并提供更多的加工选择。丙烯酸化PGS(Acr-PGS)大分子单体能够通过自由基引发机制(如氧化还原和光引发聚合)进行交联。Acr-PGS的分子量和丙烯酸化百分比的变化导致所形成网络的机械性能发生变化。一般来说,当丙烯酸化百分比保持恒定时,杨氏模量随丙烯酸化百分比的增加而增加,断裂应变百分比随分子量的增加而增加。基于这些机械性能,对一种大分子单体进行了进一步的体外和体内降解以及生物相容性研究。即使以氧化还原引发形成可注射系统,也观察到了可植入可生物降解聚合物典型的轻度至中度炎症反应。此外,通过静电纺丝和光聚合技术制备了Acr-PGS和载体聚合物聚环氧乙烷的纤维支架,纤维形态取决于这些组分的比例。该系统为可生物降解聚合物提供了可调谐的性能和增强的加工能力,以推动软组织工程方法的发展。