Wahl Denys A, Sachlos Eleftherios, Liu Chaozong, Czernuszka Jan T
Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK.
J Mater Sci Mater Med. 2007 Feb;18(2):201-9. doi: 10.1007/s10856-006-0682-9.
Scaffolds are an important aspect of the tissue engineering approach to tissue regeneration. This study shows that it is possible to manufacture scaffolds from type I collagen with or without hydroxyapatite (HA) by critical point drying. The mean pore sizes of the scaffolds can be altered from 44 to 135 microm depending on the precise processing conditions. Such pore sizes span the range that is likely to be required for specific cells. The mechanical properties of the scaffolds have been measured and behave as expected of foam structures. The degradation rate of the scaffolds by collagenase is independent of pore size. Dehydrothermal treatment (DHT), a common method of physically crosslinking collagen, was found to denature the collagen at a temperature of 120 degrees C resulting in a decrease in the scaffold's resistance to collagenase. Hybrid scaffold structures have also been manufactured, which have the potential to be used in the generation of multi-tissue interfaces. Microchannels are neatly incorporated via an indirect solid freeform fabrication (SFF) process, which could aid in reducing the different constraints commonly observed with other scaffolds.
支架是组织工程学中组织再生方法的一个重要方面。本研究表明，通过临界点干燥，有可能用或不用羟基磷灰石（HA）从I型胶原蛋白制造支架。根据精确的加工条件，支架的平均孔径可从44微米改变到135微米。这样的孔径范围涵盖了特定细胞可能需要的范围。已对支架的力学性能进行了测量，其表现符合泡沫结构的预期。支架被胶原酶降解的速率与孔径无关。发现脱氢热处理（DHT）这种物理交联胶原蛋白的常用方法在120摄氏度的温度下会使胶原蛋白变性，导致支架对胶原酶的抗性降低。还制造了混合支架结构，其有可能用于多组织界面的生成。微通道通过间接实体自由成型制造（SFF）工艺巧妙地整合在一起，这有助于减少其他支架常见的不同限制。
