Construction of Biomimetic Tissues with Anisotropic Structures via Stepwise Algorithm-Assisted Bioprinting.

Tissue-specific natural anisotropic microstructures play an important role in the normal functioning of tissues, yet they remain difficult to construct by current printing techniques. Herein, a stepwise algorithm-assisted bioprinting technology for the construction of biomimetic tissues with a customizable anisotropic microstructure by combining the Adaptive Mesh Generation algorithm and the Greedy Search algorithm is developed. Based on the mechanical topology optimization design mechanism, the Adaptive Mesh Generation algorithm can generate controllable anisotropic mesh patterns with the minimum free energy in plane models according to tissue-specific requirements. Subsequently, the Greedy Search algorithm can program the generated pattern data into optimized printing paths, effectively avoiding structural deformations caused by the multiple stacking of materials and reducing the printing time. The developed bioprinting technique is suitable for various types of bioinks including polymers, hydrogels, and organic/inorganic complexes. After combining with a calcium phosphorus bioink, the compound algorithm-assisted bioprinting technique successfully customizes femurs with biomimetic chemical compositions, anisotropic microstructures, and biological properties, demonstrating its effectiveness. Additionally, algorithm-assisted bioprinting is generally suitable for most commercial extrusion bioprinters that function in the geometric code (G-code) drive mode. Therefore, the algorithm-assisted extrusion bioprinting technology offers an intelligent manufacturing strategy for the customization of anisotropic microstructures in biomimetic tissues.

Electrospun Nanofibers for Cancer Therapy.

Lately, a remarkable progress has been recorded in the field of electrospinning for the preparation of numerous types of nanofiber scaffolds. These scaffolds present some remarkable features including high loading capacity and encapsulation efficiency, superficial area and porosity, potential for modification, structure for the co-delivery of various therapies, and cost-effectiveness. Their present and future applications for cancer diagnosis and treatment are promising and pioneering. In this chapter we provide a comprehensive overview of electrospun nanofibers (ESNFs) applications in cancer diagnosis and treatment, covering diverse types of drug-loaded electrospun nanofibers.

Engineered Customizable Microvessels for Progressive Vascularization in Large Regenerative Implants.

Inspired by the rapid angiogenesis of natural microvessels in vivo, engineered customizable microvessels (ECMVs) are developed which can naturally angiogenic sprout and induce vascular network formation via combing a celluar coaxial microfluidic extrusion technique with microsurgery post-process. ECMVs can be used for customization of primarily pre-vascularized soft tissue regenerative implants with personalized shape and vascular density with the aid of sacrificial printing technology. After collaborating with surrounding cells, ECMVs angiogenic sprouted and formed daughter vascular networks. Through techniques such as injection and suturing, ECMVs can also be introduced into large bone repair implants for pre-vascularization and osteogenesis promotion. Furthermore, the microvessel networks with personalized shapes are customized by connecting the coaxial microfluidic system to a 3D printer. It is further demonstrated that the vascularization promotion and anastomose with host vessels of the ECMVs in vivo. Thus, ECMVs provide a simple engineering strategy for rapid vascularization of clinically large regenerative soft/hard tissue implants.