The repair of large-area irregular bone defects is one of the complex problems in orthopedic clinical treatment. The bone repair scaffolds currently studied include electrospun membrane, hydrogel, bone cement, 3D printed bone tissue scaffolds, etc., among which 3D printed polymer-based scaffolds Bone scaffolds are the most promising for clinical applications. This is because 3D printing is modeled based on the im-aging results of actual bone defects so that the printed scaffolds can perfectly fit the bone defect, and the printed components can be adjusted to promote Osteogenesis. This review introduces a variety of 3D printing technologies and bone healing processes, reviews previous studies on the characteristics of commonly used natural or synthetic polymers, and clinical applications of 3D printed bone tissue scaffolds, analyzes and elaborates the characteristics of ideal bone tissue scaffolds, from t he progress of 3D printing bone tissue scaffolds were summarized in many aspects. The challenges and potential prospects in this direction were discussed.

The anticoagulation and hemostatic properties of blood-contacting materials are opposite lines of research, but their realization mechanisms are inspired by each other. Contact between blood and implantable biomaterials is a classic problem in tribological research, as both antithrombotic and hemostatic materials are closely associated with this problem. Thrombus formation on the surfaces of blood-contacting biomedical devices can detrimentally affect their performance and patient life, so specific surface functionalization is required. Currently, intensive research has focused on the development of super-lubricated or super-hydrophobic coatings, as well as coatings that deliver antithrombotic drugs. In addition, hemostatic biomaterials with porous structures, biochemical substances, and strongly adhesive hydrogels can be used to achieve rapid and effective hemostasis via physical or biochemical mechanisms. This article reviews methods of preparing anticoagulant coatings on material surfaces and the current status of rapid hemostatic materials. It also summarizes fundamental concepts for the design and synthesis of anticoagulant and hemostatic materials by discussing thrombosis and hemostasis mechanisms in biomedical devices and normal organisms. Because there are relatively few reports reviewing the progress in surface-functionalized design for anticoagulation and hemostasis, it is anticipated that this review can provide a useful summary of the applications of both bio-adhesion and bio-lubrication techniques in the field of biomedical engineering.

It is a great challenge to achieve robustly bonded, fully covered, and nanoscaled coating on the surface of electrospun nanofibers. Herein, we develop a controllable, facile, and versatile strategy to in-situ grow superlubricated nano-skin (SLNS) on the single electrospun nanofiber. Specifically, zwitterionic polymer chains are generated from the nanofiber subsurface in an inside-out way, which consequently form a robust network interpenetrating with the polymeric chains of the nanofiber matrix. The nanofibers with SLNS are superlubricated with the coefficient of friction (COF) lower than 0.025, which is about 16-fold of reduction than the original nanofibers. The time-COF plot is very stable after 12, 000 cycles of friction test, and no abrasion is observed. Additionally, the developed nanofibrous membranes possess favorable tensile property and biocompatibility. Furthermore, the nanofibrous membranes with SLNS achieve prevention of post-operative adhesion, which is confirmed in both rat tendon adhesion model and abdominal adhesion model. Compared with clinically-used antiadhesive membranes such as Interceed and DK-film, our nanofibrous membranes are not only more effective but also have the advantage of lower production cost. Therefore, this study demonstrates a potential of the superlubricated nanofibrous membranes in-situ grown based on a SLNS strategy for achieving prevention of post-operative adhesion in clinics.

After abdominopelvic surgery, there are 90-93% of patients who develop postoperative adhesions. Post-operative adhesions can occur after various surgical procedures, which not only cause a series of complications but also increase the economic burden of patients. Based on the US FDA rules, anti-adhesive products need to be deeply evaluated for their bio-functionality in animal models before clinic entrance. However, to date, there are few literatures systematically summarizing the establish approaches and evaluation standards of various post-operative adhesion animal models. Therefore, according to the importance of knowledge related to in vivo animal models, in this manuscript, the occurrence mechanism of post-operative adhesion is systematically reviewed, which is followed by summarizing the construction methods of animal adhesion models at different organs, and then the common evaluation indicators including adhesion scores and histological characterization are listed. This review is a reference to the in vivo characterizations of anti-adhesive materials.

After cardiac surgery, tissue damage to the heart may cause adhesion between heart and its surrounding tissues. Post‐operative cardiac adhesion may lead to limited normal cardiac function, decreased quality of cardiac surgery, and increased risk of major bleeding during reoperation. Therefore, it is necessary to develop an effective anti‐adhesion therapy to overcome cardiac adhesion. An injectable polyzwitterionic lubricant is developed to prevent adhesion between the heart and surrounding tissues and to maintain normal pumping function of the heart. This lubricant is evaluated in a rat heart adhesion model. Poly (2‐methacryloyloxyethyl phosphorylcholine) (i.e., PMPC) polymers are successfully prepared via free radical polymerization of monomer MPC, and the optimal lubricating performance, biocompatibility both in vitro and in vivo is demonstrated. Besides, a rat heart adhesion model is conducted to evaluate the bio‐functionality of lubricated PMPC. The results prove that PMPC is a promising lubricant for complete adhesion‐prevention. The injectable polyzwitterionic lubricant shows excellent lubricating properties and biocompatibility and can effectively prevent cardiac adhesion.