Zhao Ling, Zhang Zhibing
Centre for Formulation Engineering, Chemical Engineering, School of Engineering, University of Birmingham, Edgbaston, Birmingham, UK.
Artif Cells Blood Substit Immobil Biotechnol. 2004 Feb;32(1):25-40. doi: 10.1081/bio-120028666.
The mechanical properties of biocompatible microparticles including alginate microspheres and alginate-chitosan microcapsules with different wall thickness were determined using a micromanipulation technique. Single microparticles with diameters of 20-60 microm were compressed to a given deformation and held, and compressed to rupture at different speeds. The corresponding force imposed on them was measured simultaneously by a force transducer. Results showed that the force imposed on these particles increased when they were compressed, but relaxed significantly when they were held. For alginate microspheres, the faster the compression speed was, the greater the force being imposed on them at a given deformation. Alginate-chitosan microcapsules showed less force relaxation when they were held, compared with alginate microspheres. The thicker their wall was, the less significant force relaxation the microcapsules exhibited. The mean rupture force of alginate microspheres increased with the compression speed, but this effect in general became less for alginate-chitosan microcapsules, which depended on their wall thickness. However, the deformation at rupture for all three samples was independent of the compression speed. On average, the alginate-chitosan microcapsules were bigger than alginate microspheres and had a greater rupture force.
采用微操纵技术测定了具有不同壁厚的生物相容性微粒（包括海藻酸钠微球和海藻酸钠 - 壳聚糖微胶囊）的力学性能。将直径为20 - 60微米的单个微粒压缩至给定变形并保持，然后以不同速度压缩至破裂。力传感器同时测量施加在它们上面的相应力。结果表明，这些微粒在被压缩时所受的力增加，但在保持时力会显著松弛。对于海藻酸钠微球，压缩速度越快，在给定变形下施加在它们上面的力就越大。与海藻酸钠微球相比，海藻酸钠 - 壳聚糖微胶囊在保持时力的松弛较小。其壁越厚，微胶囊表现出的力松弛越不明显。海藻酸钠微球的平均破裂力随压缩速度增加，但对于海藻酸钠 - 壳聚糖微胶囊，这种影响总体上变小，这取决于它们的壁厚。然而，所有三个样品的破裂变形与压缩速度无关。平均而言，海藻酸钠 - 壳聚糖微胶囊比海藻酸钠微球更大，并且具有更大的破裂力。
