Preparation and characterization of a stereocomplex of poly(lactide-co-ε-caprolactone)/tricalcium phosphate biocomposite using supercritical fluid technology

Abstract

Absorbable materials are attractive for internal fracture fixation devices. They have advantages in the reduction of stress shielding, secondary operations for removal are no longer required, and the risks of complications are reduced [1]. Biopolymers such as polylactide, poly(glycolic acid), poly(!-caprolactone), and their copolymers attract great attention due to their biodegradability and biocompatibility. The major limitation of those materials is that their mechanical properties (as strength, toughness, elastic modulus) are lower than the mechanical properties of cortical bones. Abstract. A novel biocomposite material from a stereocomplex of poly (L-lactide-co-!-caprolactone) (PLLCL) and poly (D-lactide-co-!-caprolactone) (PDLCL) and inorganic tricalcium phosphate (TCP) was prepared by supercritical fluid method. Both pristine and poly (L-lactide)-grafted-TCP (PLLA-g-TCP) were used. PLLA-g-TCP was produced by ringopening polymerization of L-lactide in the presence of surface-activated TCP. Infrared (IR) spectroscopy and scanning electron microscopic (SEM) images confirm the attachment of PLLA onto the activated TCP surface. The stereocomplex formation of biocomposite was confirmed by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The biocomposite containing PLLA-g-TCP has higher stereocomplex degree and more homogeneous TCP distribution compared to the biocomposite containing pristine TCP. The presence of PLLA-g-TCP in the stereocomplex PLLCL-PDLCL (s-PDLCL) enhance the stereocomplex degree up to a certain content and also supports the homogeneous TCP dispersion in the stereocomplex matrix. These phenomena support the improvement in mechanical properties of the s-PDLCL composite the optimum content of PLLA-g-TCP being 10%. The biocomposites containing TCP materials are promising materials for biomedical application, especially for bone tissue engineering.

Development of Stereocomplex Polylactide Nanocomposites as an Advanced Class of Biomaterials—A Review

“…s-PLA can be obtained from a mixture of PLA homopolymers [ 2 , 3 , 4 , 5 , 14 , 16 , 19 , 20 , 21 , 22 , 26 , 27 , 28 ] copolymers, [ 9 , 28 , 29 , 30 , 35 ] and branched structures [ 23 , 36 ]. Structural modification affects the properties of synthesized s-PLA materials, including their crystallinity, morphology, stability, degradability, and mechanical properties [ 6 , 23 , 28 , 32 , 36 , 37 , 38 ].…”

“…Because of its biodegradability and sustainability, PLA is a promising material for replacing non-degradable materials. By combining stereocomplexation and nanocomposite approaches to generate stereo-nano PLA, the synergistic effect of both approaches is expected to enhance the properties of the materials and create the opportunity for its use in advanced performance applications [ 19 , 28 , 29 , 30 ]. The development of stereo-nano PLA enables the design and modification of biodegradables materials so that an eco-friendly product with high-performance, specially designed, and engineered properties is achieved.…”

Supercritical fluid technology parameters affecting size and behavior of stereocomplex polylactide particles and their composites

“…Our research group has also researched many studies for a fast and facile approach of SCF technology on various perspectives [15,16,18,20,21]. Furthermore, these sc-PLA particles can be used as filler to make composites with a biodegradable PLLA matrix of the same composition [22][23][24][25]. Thus, controlling the size and behavior of sc-PLA particles after stereocomplexation is very important to extend their possible applications.…”