de Paula Márcio, Goissis Gilberto, Martins Virginia Conceição Amaro
Laboratório de Bioquímica/Biomateriais. Departamento de Química e Física Molecular do Instituto de Química de São Carlos, Universidade de São Paulo, Av do Trabalhador Sãocarlense, 400 São Carlos, Sao Paulo, SP, Brazil.
J Mater Sci Mater Med. 2007 Sep;18(9):1683-90. doi: 10.1007/s10856-007-3058-x. Epub 2007 May 5.
The present paper describes the rheological properties of anionic collagen gels and anionic collagen:rhamsan composites gels in the concentration of 0.7, 4 and 6%, estimated to be used as injectable biomaterials for plastic reconstruction. Rheological studies of these gels showed that independently of pH, composition and concentration the viscoelastic behavior was dependent on the frequency, with the storage modulus always greater than the loss modulus (G' > G'' and delta < 45 degrees ). Creep experiments showed that anionic collagen:rhamsan composites equilibrated at pH 7.4 were less elastic and more susceptible to deformation in comparison to gels equilibrated at pH 3.5. Flow experiments indicated that the force needed for the extrusion of anionic collagen:rhamsan composites, in comparison to anionic collagen, was significantly smaller and with a smoother flow, suggesting the association with rhamsan may be a good alternative in the replacement of glutaraldehyde to stabilize the microfibril assembly of commercial collagen gel preparations. Finally, on the basis of dynamic viscosity profiles found for different preparations, some of these composites are potential candidates to be utilized in laryngology.
本文描述了浓度为0.7%、4%和6%的阴离子胶原蛋白凝胶以及阴离子胶原蛋白：鼠李聚糖复合凝胶的流变学特性，这些凝胶预计用作整形重建的可注射生物材料。对这些凝胶的流变学研究表明，无论pH值、组成和浓度如何，粘弹性行为都取决于频率，储能模量总是大于损耗模量（G' > G''且δ < 45°）。蠕变实验表明，与在pH 3.5平衡的凝胶相比，在pH 7.4平衡的阴离子胶原蛋白：鼠李聚糖复合材料弹性较小，更容易变形。流动实验表明，与阴离子胶原蛋白相比，挤出阴离子胶原蛋白：鼠李聚糖复合材料所需的力明显更小，流动更顺畅，这表明与鼠李聚糖结合可能是替代戊二醛以稳定商业胶原蛋白凝胶制剂微纤维组装的良好选择。最后，根据不同制剂的动态粘度曲线，其中一些复合材料有望用于喉科学。
