Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
J Biomed Mater Res A. 2013 Apr;101(4):1095-102. doi: 10.1002/jbm.a.34400. Epub 2012 Sep 24.
The objective of the present in vitro study was to investigate cardiomyocyte functions, specifically their adhesion and proliferation, on injectable scaffolds containing RNT (rosette nanotubes) and CNF (carbon nanofibers) in a pHEMA (poly(2-hydroxyethyl methacrylate)) hydrogel to determine their potential for myocardial tissue engineering applications. RNTs are novel biocompatible nanomaterials assembled from synthetic analogs of DNA bases guanine and cytosine that self-assemble within minutes when placed in aqueous solutions at body temperatures. These materials could potentially improve cardiomyocyte functions and solidification time of pHEMA and CNF composites. Because heart tissue is conductive, CNFs were added to pHEMA to increase the composite's conductivity. Our results showed that cardiomyocyte density increased after 4 h, 1 day, and 3 days with greater amounts of CNFs and greater amounts of RNTs in pHEMA (up to 10 mg mL(-1) CNFs and 0.05 mg mL(-1) RNTs). Factors that may have increased cardiomyocyte functions include greater wettability, conductivity, and an increase in surface nanoroughness with greater amounts of CNFs and RNTs. In effect, contact angles measured on the surface of the composites decreased while the conductivity and surface roughness increased as CNFs and RNTs content increased. Lastly, the ultimate tensile modulus decreased for composites with greater amounts of CNFs. In summary, the properties of these injectable composites make them promising candidates for myocardial tissue engineering applications and should be further studied.
本体外研究的目的是研究含有 RNT（玫瑰花结纳米管）和 CNF（碳纳米纤维）的可注射支架对心肌细胞功能的影响，特别是其黏附和增殖能力，以确定它们在心肌组织工程应用中的潜力。RNTs 是一种新型的生物相容性纳米材料，由 DNA 碱基鸟嘌呤和胞嘧啶的合成类似物组装而成，当放置在体温下的水溶液中时，它们会在几分钟内自行组装。这些材料有可能改善心肌细胞的功能和 pHEMA 与 CNF 复合材料的凝固时间。由于心脏组织具有导电性，因此在 pHEMA 中添加了 CNF 以提高复合材料的导电性。我们的研究结果表明，随着 pHEMA 中 CNF 含量和 RNTs 含量的增加（高达 10mg/mL 的 CNF 和 0.05mg/mL 的 RNTs），心肌细胞密度在 4 小时、1 天和 3 天后增加。可能增加心肌细胞功能的因素包括更大的润湿性、导电性和随着 CNF 和 RNTs 含量增加而增加的表面纳米粗糙度。实际上，随着复合材料中 CNF 和 RNTs 含量的增加，测量的表面接触角降低，而导电性和表面粗糙度增加。最后，随着 CNF 含量的增加，复合材料的极限拉伸模量降低。总之，这些可注射复合材料的特性使它们成为心肌组织工程应用的有前途的候选材料，应该进一步研究。
