No abstract

In recent years, Bioprinting technologies have been advancing at the convergence of automation, digitalization, and new tissue engineering (TE) approaches, In-situ bioprinting may be favored during certain situations for skin wound healing. The main advantage of in-situ printing is that the printed wound surface has good adhesion, namely the print of dressing can full fill the defect out of the wound, can adapt to different positions (joints) of the different types of wounds. In addition, the free deposition of materials and the properties of materials are well combined with the wound surface in the printing process, sticking to the wound surface and reducing the pain caused to the injured by the process. Handheld device to achieve in-situ printing, simplifies the surgical process, portable, easy to operate, can be used in emergency scenarios. Moreover, wound healing is a dynamic and complex process that contains several sequential phases. Rapid hemostasis and continuous bacteriostasis have always been problems in wound healing. Here, we firstly propose a hand-held device that combines multiple processes (spray, extrusion, electrospinning) and is oriented to accurate wound management. Secondly, we used this device to achieved the stable film formation of a variety of materials, and has the key functions of hemostasis, bacteriostasis and promoting healing. Finally, we highlight the potential of this device for wound healing applications.

As the largest organ of the human body, the skin has a complex multi-layered structure. The composition of the skin includes cells, extracellular matrix (ECM), vascular networks, and other appendages....

The diameter of most blood vessels in cardiovascular and peripheral vascular system is less than 6 mm. Because the inner diameter of such vessels is small, a built-in stent often leads to thrombosis and other problems. It is an important goal to replace it directly with artificial vessels. This paper creatively proposed a preparation method of a small-diameter artificial vascular graft which can form a controllable microstructure on the inner wall and realize a multi-material composite. On the one hand, the inner wall of blood vessels containing direct writing structure is constructed by electrostatic direct writing and micro-imprinting technology to regulate cell behavior and promote endothelialization; on the other hand, the outer wall of blood vessels was prepared by electrospinning PCL to ensure the stability of mechanical properties of composite grafts. By optimizing the key parameters of the graft, a small-diameter artificial blood vessel with controllable microstructure on the inner wall is finally prepared. The corresponding performance characterization experimental results show that it has advantages in structure, mechanical properties, and promoting endothelialization.

Skin is one of the largest and most important organs in the human body. When faced with a large, full-thickness skin burn, there is not enough healthy skin to graft. In this case, we can replace our skin with biomaterials. Due to its characteristics of water permeability, antibacterial properties, biocompatibility, self-debridement, and so on, the hydrogel is undoubtedly a better alternative material. Among the methods of hydrogel preparation, in situ material molding has attracted a lot of attention for its unique advantages. Here, we proposed an in situ forming process based on transfer printing and verified the feasibility of the transfer printing process using a three-axis platform. The in situ molding equipment was designed to realize the in situ material transfer process, which prepared the conditions for the subsequent process optimization, cell experiment verification, and animal experiment.