Bionic structure and blood compatibility of highly oriented homo-epitaxially crystallized poly(l-lactic acid).

A highly oriented poly(l-lactic acid) (PLLA), with a blood vessel-like biomimetic structure, was fabricated using solid-phase hot drawing technology and homo-epitaxial crystallization to improve the mechanical properties and biocompatibility of PLLA. Long chain branched PLLA (LCB-PLLA) was prepared through a two-step ring-opening reaction, and a consequent draw as high as 1000 % was achieved during the hot drawing. The modulus and tensile strength were found to have increased through the formation of oriented shish-kebab like crystals along the drawing direction during processing. Furthermore, PLLA nano-lamellae were formed on the surface of the oriented plates via the introduction of homo-epitaxial crystallization. The high degree of orientation and epitaxial crystallization substantially enhanced the biocompatibility of the PLLA by prolonging clotting time, decreasing the rate of hemolysis, and increasing the cell growth and reproduction of the osteoblasts.

Hierarchical Structures Composed of Cu(OH)2 Nanograss within Directional Microporous Cu for Glucose Sensing.

Cu(OH)2 nanomaterials are widely investigated for non-enzymatic glucose sensors due to their low-cost and excellent performance. Cu(OH)2 nanomaterials usually grow on substrates to form sensor electrodes. Reported works mainly focus on structure adjusting of the Cu(OH)2 nanostructures, while the optimization of substrates is still lacking. In the present work, directional porous Cu (DPC) was applied as the substrate for the growth of Cu(OH)2 nanograss (NG), and hierarchical structures of Cu(OH)2@DPC were prepared by alkaline oxidation. The morphology and microstructure evolution of the prepared hierarchical structures was investigated, and the non-enzymatic glucose sensing performance was evaluated. Cu(OH)2@DPC exhibits enhanced comprehensive non-enzymatic glucose sensing performance compared to the reported ones, which may benefit from both the effective adsorption of the Cu(OH)2 NG with a relatively high surface area and the high solute exchange of the DPC by a channel effect. This work provides new insights into the further improvement of the non-enzymatic glucose sensing performance of Cu(OH)2 nanostructures by optimizing the substrate structure.