An attempt to maintain the three-dimensional space into restorative sites through the conveniently pack porous fillers are general used strategy. Advancement in the manufacturing protective shells in the scaffolds, which would be filled with brittle ceramic grafts for the development of highly connective pores provides the approach to solve crack problem for generating the tissues. Therefore, multilayered braided and alkalized poly(lactic acid) (PLA) composites with calcium phosphate bone cement (CPC) were synthesized and compared. The PLA/CPC composites were divided into various groups according to a series of heat-treatment temperatures (100-190 °C) and periods (1-3 h) and then characterized. The effects of 24-h immersion on the strength decay resistance of the samples were compared. Results showed that the residual oil capped on the surfaces of alkalized PLA braid was removed, and the structure was unaltered. However, the reduced tensile stress of alkalized PLA braids was due to ester-group formation by hydrolysis. Mechanical test results of PLA/CPC composites showed that the strength significantly increased after heat treatment, except when the heating temperature was higher than the PLA melting point at approximately 160-170 °C. The degree of PLA after recrystallization became higher than that of unheated composites, thereby leading to reduced strength and toughness of the specimen. Braiding fibers of biodegradable PLA reinforced and toughened the structure particularly of the extra-brittle material of thin-sheet CPC after implantation.

Composites comprising a braided poly(lactic) acid (PLA) filament and calcium phosphate bone cement (CPC) were inferred to maintain space and to pack porous fillers into restorative sites. Composites of alkalized multilayer-PLA braids and CPC (PLA/CPC) were divided into various groups according to a series of heat-treatment periods that lasted for 60, 90, 120, 150, and 180 min at 160℃; subsequently, these composites were characterized. Strength decays of samples were also compared after 24 h immersion in Hanks’s physiological solution. Results showed that the PLA/CPC specimens were toughened after treatment at 160℃ for 120 min. Furthermore, the moduli of PLA/CPC groups increased significantly when the heating time was more than 150 min; this effect was generated by the cold crystallization within the PLA filaments. The reduced stress in the composites after immersion was attributed to the fibers that protruded from the scaffold surface and to hydrolysis. The mechanical test results for the PLA/CPC composites indicated that the toughening effect was strengthened significantly under prolonged heat treatment, especially when the heating time was longer than 150 min. The cold crystallization degree of PLA increased, thereby enhancing the strength and toughness of a specimen before immersion. Thus, PLA/CPC composites can be used to simulate potential bone functions as well as to maintain three-dimensional spaces and pack porous fillers into restorative sites conveniently.