Sousa M P, Cleymand F, Mano J F
3B's Research Group-Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal. ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal. Present address: Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
Biomed Mater. 2016 May 20;11(3):035008. doi: 10.1088/1748-6041/11/3/035008.
Freestanding multilayered films were obtained using layer-by-layer (LbL) technology from the assembly of natural polyelectrolytes, namely chitosan (CHT) and chondroitin sulfate (CS). The morphology and the transparency of the membranes were evaluated. The influence of genipin (1 and 2 mg ml(-1)), a naturally-derived crosslinker agent, was also investigated in the control of the mechanical properties of the CHT/CS membranes. The water uptake ability can be tailored by changing the crosslinker concentration that also controls the Young's modulus and ultimate tensile strength. The maximum extension tends to decrease upon crosslinking with the highest genipin concentration, compromising the elastic properties of CHT/CS membranes: nevertheless, when using a lower genipin concentration, the ultimate tensile stress is similar to the non-crosslinked one, but exhibits a significantly higher modulus. Moreover, the crosslinked multilayer membranes exhibited shape memory properties, through a simple hydration action. The in vitro biological assays showed better L929 cell adhesion and proliferation when using the crosslinked membranes and confirmed the non-cytotoxicity of the developed CHT/CS membranes. Within this research work, we were able to construct freestanding biomimetic multilayer structures with tailored swelling, mechanical and biological properties that could find applicability in a variety of biomedical applications.
通过层层（LbL）技术，由天然聚电解质壳聚糖（CHT）和硫酸软骨素（CS）组装获得了独立的多层膜。对膜的形态和透明度进行了评估。还研究了天然衍生的交联剂京尼平（1和2 mg ml(-1)）对CHT/CS膜力学性能的影响。通过改变交联剂浓度可以调整吸水能力，而交联剂浓度也控制着杨氏模量和极限拉伸强度。与最高浓度的京尼平交联时，最大伸长率趋于降低，这会损害CHT/CS膜的弹性性能：然而，当使用较低浓度的京尼平时，极限拉伸应力与未交联的膜相似，但模量显著更高。此外，通过简单的水合作用，交联多层膜表现出形状记忆特性。体外生物学试验表明，使用交联膜时L929细胞的粘附和增殖情况更好，并证实了所制备的CHT/CS膜无细胞毒性。在这项研究工作中，我们能够构建具有定制的膨胀、力学和生物学特性的独立仿生多层结构，这些结构可在多种生物医学应用中找到适用性。
