Abstract:
Bioengineering seeks to replicate biological tissues exploiting scaffolds often based on polymeric biomaterials. Digital light processing (DLP) has emerged as a potent technique to fabricate tissue engineering (TE) scaffolds. However, the scarcity of suitable biomaterials with desired physico-chemical properties along with processing capabilities limits DLP\'s potential. Herein, we introduce acrylate-endcapped urethane-based polymers (AUPs) for precise physico-chemical tuning while ensuring optimal computer-aided design/computer-aided manufacturing (CAD/CAM) mimicry. Varying the polymer backbone (i.e. poly(ethylene glycol) (PEG) versus poly(propylene glycol) (PPG)) and photo-crosslinkable endcap (i.e. di-acrylate versus hexa-acrylate), we synthesized a series of photo-crosslinkable materials labeled as UPEG2, UPEG6, UPPG2 and UPPG6. Comprehensive material characterization including physico-chemical and biological evaluations, was followed by a DLP processing parametric study for each material. The impact of the number of acrylate groups per polymer (2 to 6) on the physico-chemical properties was pronounced, as reflected by a reduced swelling, lower water contact angles, accelerated crosslinking kinetics, and increased Young\'s moduli upon increasing the acrylate content. Furthermore, the different polymer backbones also exerted a substantial effect on the properties, including the absence of crystallinity, remarkably reduced swelling behaviors, a slight reduction in Young\'s modulus, and slower crosslinking kinetics for UPPG vs UPEG. The mechanical characteristics of DLP-printed samples showcased the ability to tailor the materials\' stiffness (ranging from 0.4 to 5.3 MPa) by varying endcap chemistry and/or backbone. The in vitro cell assays confirmed biocompatibility of the material as such and the DLP-printed discs. Furthermore, the structural integrity of 3D scaffolds was preserved both in dry and swollen state. By adjusting the backbone chemistry or acrylate content, the post-swelling dimensions could be customized towards the targeted application. This study showcases the potential of these materials offering tailorable properties to serve many biomedical applications such as cartilage TE.
摘要:
生物工程试图利用通常基于聚合物生物材料的支架来复制生物组织。数字光处理(DLP)已成为制造组织工程(TE)支架的有效技术。然而,缺乏具有所需物理化学性质和加工能力的合适生物材料限制了DLP的潜力。在这里,我们引入丙烯酸酯封端的氨基甲酸酯基聚合物(AUP)进行精确的物理化学调整,同时确保最佳的计算机辅助设计/计算机辅助制造(CAD/CAM)模拟。改变聚合物主链(即,聚(乙二醇)(PEG)与聚(丙二醇)(PPG))和可光交联的封端(即,二丙烯酸酯与六丙烯酸酯),我们合成了一系列被标记为UPEG2、UPEG6、UPPG2和UPPG6的光交联材料。全面的材料表征,包括物理化学和生物学评估,然后对每种材料进行DLP处理参数研究。每个聚合物(2至6)的丙烯酸酯基团数量对物理化学性质的影响是明显的,如肿胀减少所反映的,较低的水接触角,加速交联动力学,并在增加丙烯酸酯含量时增加杨氏模量。此外,不同的聚合物骨架也对性能产生了实质性的影响,包括没有结晶度,显著减少肿胀行为,杨氏模量略有降低,UPPG与UPEG的交联动力学较慢。DLP打印样品的机械特性显示了通过改变端盖化学和/或骨架来调整材料刚度(范围从0.4到5.3MPa)的能力。体外细胞测定证实了材料本身和DLP打印的光盘的生物相容性。此外,在干燥和溶胀状态下,3D支架的结构完整性得以保留。通过调节主链化学或丙烯酸酯含量,可以针对目标应用定制膨胀后尺寸。这项研究展示了这些材料的潜力,提供可定制的特性,以服务于许多生物医学应用,如软骨TE。