Appropriate biomimetic scaffolds created via 3D bioprinting are promising methods for treating damaged menisci. However, given the unique anatomical structure and complex stress environment of the meniscus, many studies have adopted various techniques to take full advantage of different materials, such as the printing combined with infusion, or electrospining, to chase the biomimetic meniscus, which makes the process complicated to some extent. Some researchers have tried to tackle the challenges only by 3D biopringting, while its alternative materials and models have been constrained. In this study, based on a multilayer biomimetic strategy, we optimized the preparation of meniscus-derived bioink, gelatin methacrylate (GelMA)/meniscal extracellular matrix (MECM), to take printability and cytocompatibility into account together. Subsequently, a customized 3D bioprinting system featuring a dual nozzle + multitemperature printing was used to integrate the advantages of polycaprolactone (PCL) and meniscal fibrocartilage chondrocytes (MFCs)-laden GelMA/MECM bioink to complete the biomimetic meniscal scaffold, which had the best biomimetic features in terms of morphology and components. Furthermore, cell viability, mechanics, biodegradation and tissue formation in vivo were performed to ensure that the scaffold had sufficient feasibility and functionality, thereby providing a reliable basis for its application in tissue engineering.

Human cartilage tissue can be categorized into three types: hyaline cartilage, elastic cartilage and fibrocartilage. Each type of cartilage tissue possesses unique properties and functions, which presents a significant challenge for the regeneration and repair of damaged tissue. Bionics is a discipline in which humans study and imitate nature. A bionic strategy based on comprehensive knowledge of the anatomy and histology of human cartilage is expected to contribute to fundamental study of core elements of tissue repair. Moreover, as a novel tissue-engineered technology, 3D bioprinting has the distinctive advantage of the rapid and precise construction of targeted models. Thus, by selecting suitable materials, cells and cytokines, and by leveraging advanced printing technology and bionic concepts, it becomes possible to simultaneously realize multiple beneficial properties and achieve improved tissue repair. This article provides an overview of key elements involved in the combination of 3D bioprinting and bionic strategies, with a particular focus on recent advances in mimicking different types of cartilage tissue.

Breast cancer is the second leading cause of cancer-related deaths among women worldwide. Many patients suffer from bone metastasis. Sclerostin, a key regulator of normal bone remodeling, is critically involved in osteolytic bone diseases. However, its role in breast cancer bone metastasis remains unknown. Here, we found that sclerostin was overexpressed in breast cancer tumor tissues and cell lines. Inhibition of sclerostin by antibody (Scl-Ab) significantly reduced migration and invasion of MDA-MB-231 and MCF-7 cells in a time- and dose-dependent manner. In xenograft model, sclerostin inhibition improved survival of nude mice and prevented osteolytic lesions resulting from tumor metastasis. Taken together, sclerostin promotes breast cancer cell migration, invasion and bone osteolysis. Inhibition of sclerostin may serve as an efficient strategy for interventions against breast cancer bone metastasis or osteolytic bone diseases.

The rapid advancement of artificial intelligence has brought significant breakthroughs to various medical disciplines，This study aimed to compare perioperative factors and postoperative hip function recovery in primary total hip arthroplasty (THA)by evaluating the use of an artificial intelligence (AI) preoperative planning system versus traditional two-dimensional X-ray planning. A total of 45 eligible patients underwent primary THA at Beijing Shijitan Hospital, Capital Medical University, between July 2022 and August 2022. The patients were randomly assigned to either the experimental group (n = 19) or the control group (n = 26). The experimental group utilized AI planning, while the control group employed traditional two-dimensional X-ray planning. Statistical analysis was performed to compare the accuracy of prosthesis prediction, operation time, intraoperative blood loss, frequency of intraoperative model testing, length of hospital stay, postoperative imaging data, and postoperative hip function scores. These comparisons were made to assess the effects of different preoperative planning methods on perioperative and postoperative hip function recovery. The accuracy of preoperative planning for the acetabular and femoral sides in AI-assisted total hip arthroplasty was 84.2 % and 89.5 %, respectively, which was significantly better than that of the traditional two-dimensional X-ray planning group (P < 0.05). The operation time for AI-assisted total hip arthroplasty was 104.32 ± 18.10 min, which was shorter than that of the traditional two-dimensional X-ray planning group (P < 0.05). At 3 months post-operation, the grade of Harris score for hip function in the AI planning group was significantly better than that in the traditional two-dimensional X-ray planning group (P < 0.05). The average postoperative Harris score of the artificial intelligence group was higher than that of the traditional two-dimensional X-ray planning (P < 0.05). Artificial intelligence-assisted total hip arthroplasty demonstrated superior accuracy in prosthesis prediction, shorter operation time, higher average Harris score at postoperative follow-up, and better hip function recovery at 3 months compared to traditional two-dimensional X-ray planning. III, case-control study.

Osteoporotic fracture is one of the most common bone diseases in middle and old age, as the most serious consequence of osteoporosis. Sclerostin single‐chain antibody fragments (SCL‐scFv) has been proven to promote bone formation by binding to scleroprotein, a natural antagonist of the Wnt pathway, but it is difficult to rule alone due to the weak permeability and immunogenicity. Herein, we prepared poly(lactic‐co‐glycolic acid) (PLGA) microspheres as a sustained‐release vehicle to prolong the activity of SCL‐scFv. The morphology of microspheres were uniform and nearly sphere, loading efficiency and encapsulation efficiency of SCL‐scFv microspheres were 6.28±1.04% and 48.37 ± 8.11 %, respectively. Approximately 90% of the SCL‐scFvs were released from the microspheres over 28 days with initial burst releasing (38%) in the first four days. Sustained release of active SCL‐scFv from microspheres promoted bone marrow mesenchymal stem cells (BMSCs) osteogenic differentiation in vitro and enhanced fracture healing in ovariectomized (OVX) rats by improving bone mass and bone formation in the fracture region. All these findings demonstrate that the microspheres are able to simultaneously achieve localized long‐term SCL‐scFv controlled release and effectively promote bone formation, which provides a promising approach for osteoporotic fracture.