3D-Printed Composite Bioceramic Scaffolds for Bone and Cartilage Integrated Regeneration.

Osteoarthritis may result in both cartilage and subchondral bone damage. It is a significant challenge to simultaneously repair cartilage due to the distinct biological properties between cartilage and bone. Here, strontium copper tetrasilicate/ß-tricalcium phosphate (Wesselsite[SrCuSi4O10]/Ca3(PO4)2, WES-TCP) composite scaffolds with different WES contents (1, 2, and 4 wt %) were fabricated via a three-dimensional (3D) printing method for the osteochondral regeneration. The physicochemical properties and biological activities of the scaffolds were systematically investigated. 2WES-TCP (WES-TCP with 2 wt % WES) composite scaffolds not only improved the compressive strength but also enhanced the proliferation of both rabbit bone mesenchymal stem cells (rBMSCs) and chondrocytes, as well as their differentiation. The in vivo study further confirmed that WES-TCP scaffolds significantly promoted the regeneration of both bone and cartilage tissue in rabbit osteochondral defects compared with pure TCP scaffolds owing to the sustained and controlled release of bioactive ions (Si, Cu, and Sr) from bioactive scaffolds. These results show that 3D-printed WES-TCP scaffolds with bilineage bioactivities take full advantage of the bifunctional properties of bioceramics to reconstruct the complex osteochondral interface, which broadens the approach to engineering therapeutic platforms for biomedical applications.

Bioprinted constructs that simulate nerve-bone crosstalk to improve microenvironment for bone repair.

Crosstalk between nerves and bone is essential for bone repair, for which Schwann cells (SCs) are crucial in the regulation of the microenvironment. Considering that exosomes are critical paracrine mediators for intercellular communication that exert important effects in tissue repair, the aim of this study is to confirm the function and molecular mechanisms of Schwann cell-derived exosomes (SC-exos) on bone regeneration and to propose engineered constructs that simulate SC-mediated nerve-bone crosstalk. SCs promoted the proliferation and differentiation of bone marrow mesenchymal stem cells (BMSCs) through exosomes. Subsequent molecular mechanism studies demonstrated that SC-exos promoted BMSC osteogenesis by regulating the TGF-ß signaling pathway via let-7c-5p. Interestingly, SC-exos promoted the migration and tube formation performance of endothelial progenitor cells. Furthermore, the SC-exos@G/S constructs were developed by bioprinting technology that simulated SC-mediated nerve-bone crosstalk and improved the bone regeneration microenvironment by releasing SC-exos, exerting the regulatory effect of SCs in the microenvironment to promote innervation, vascularization, and osteogenesis and thus effectively improving bone repair in a cranial defect model. This study demonstrates the important role and underlying mechanism of SCs in regulating bone regeneration through SC-exos and provides a new engineered strategy for bone repair.

3D bioprinting tumor models mimic the tumor microenvironment for drug screening.

Cancer is a severe threat to human life and health and represents the main cause of death globally. Drug therapy is one of the primary means of treating cancer; however, most anticancer medications do not proceed beyond preclinical testing because the conditions of actual human tumors are not effectively mimicked by traditional tumor models. Hence, bionic in vitro tumor models must be developed to screen for anticancer drugs. Three-dimensional (3D) bioprinting technology can produce structures with built-in spatial and chemical complexity and models with accurately controlled structures, a homogeneous size and morphology, less variation across batches, and a more realistic tumor microenvironment (TME). This technology can also rapidly produce such models for high-throughput anticancer medication testing. This review describes 3D bioprinting methods, the use of bioinks in tumor models, and in vitro tumor model design strategies for building complex tumor microenvironment features using biological 3D printing technology. Moreover, the application of 3D bioprinting in vitro tumor models in drug screening is also discussed.

Regulated macrophage immune microenvironment in 3D printed scaffolds for bone tumor postoperative treatment.

The 3D printing technique is suitable for patient-specific implant preparation for bone repair after bone tumor resection. However, improving the survival rate due to tumor recurrence remains a challenge for implants. The macrophage polarization induction to M2-type tumor-associated macrophages (TAMs) by the tumor microenvironment is a key factor of immunosuppression and tumor recurrence. In this study, a regenerative scaffold regulating the macrophage immune microenvironment and promoting bone regeneration in a dual-stage process for the postoperative treatment of bone tumors was constructed by binding a colony-stimulating factor 1 receptor (CSF-1R) inhibitor GW2580 onto in situ cosslinked hydroxybutylchitosan (HBC)/oxidized chondroitin sulfate (OCS) hydrogel layer covering a 3D printed calcium phosphate scaffold based on electrostatic interaction. The hydrogel layer on scaffold surface not only supplied abundant sulfonic acid groups for stable loading of the inhibitor, but also acted as the cover mask protecting the bone repair part from exposure to unhealthy growth factors in the microenvironment at the early treatment stage. With local prolonged release of inhibitor being realized via the functional material design, CSF-1R, the main pathway that induces polarization of TAMs, can be efficiently blocked, thus regulating the immunosuppressive microenvironment and inhibiting tumor development at a low therapeutic dose. At the later stage of treatment, calcium phosphate component of the scaffold can facilitate the repair of bone defects caused by tumor excision. In conclusion, the difunctional 3D printed bone repair scaffold regulating immune microenvironment in stages proposed a novel approach for bone tumor postoperative treatment.

Development and Application of Three-Dimensional Bioprinting Scaffold in the Repair of Spinal Cord Injury.

Spinal cord injury (SCI) is a disabling and destructive central nervous system injury that has not yet been successfully treated at this stage. Three-dimensional (3D) bioprinting has become a promising method to produce more biologically complex microstructures, which fabricate living neural constructs with anatomically accurate complex geometries and spatial distributions of neural stem cells, and this is critical in the treatment of SCI. With the development of 3D printing technology and the deepening of research, neural tissue engineering research using different printing methods, bio-inks, and cells to repair SCI has achieved certain results. Although satisfactory results have not yet been achieved, they have provided novel ideas for the clinical treatment of SCI. Considering the potential impact of 3D bioprinting technology on neural studies, this review focuses on 3D bioprinting methods widely used in SCI neural tissue engineering, and the latest technological applications of bioprinting of nerve tissues for the repair of SCI are discussed. In addition to introducing the recent progress, this work also describes the existing limitations and highlights emerging possibilities and future prospects in this field.

Multiscale Hierarchical Architecture-Based Bioactive Scaffolds for Versatile Tissue Engineering.

Artificial construction from tendon to bone remains a formidable challenge in tissue engineering owing to their structural complexity. In this work, bioinspired calcium silicate nanowires and alginate composite hydrogels are utilized as building blocks to construct multiscale hierarchical bioactive scaffolds for versatile tissue engineering from tendon to bone. By integrating 3D printing technology and mechanical stretch post-treatment in a confined condition, the obtained composite hydrogels possess bioinspired reinforcement architectures from nano- to submicron- to microscale with significantly enhanced mechanical properties. The biochemical and topographical cues of the composite hydrogel scaffolds provide much more efficient microenvironment to the rabbit bone mesenchymal stem cells and rabbit tendon stem cells, leading to ordered alignment and improved differentiation. The composite hydrogels markedly promote in vivo tissue regeneration from bone to tendon, especially fibrocartilage transitional tissue. Therefore, such calcium silicate nanowires/alginate composite hydrogels with multiscale hierarchical structures have potential application for tissue regeneration from tendon to bone. This work provides an innovative strategy to construct multiscale hierarchical architecture-based scaffolds for tendon/bone engineering.

Traditional Chinese herbal medicine in treating amenorrhea caused by antipsychotic drugs: Meta-analysis and systematic review.

ETHNOPHARMACOLOGICAL RELEVANCE: Amenorrhea caused by antipsychotic drugs is not uncommon in clinical practice, and various treatment strategies are used to treat the condition. Chinese herbal medicine has its own theory for amenorrhea caused by antipsychotic drugs and has developed its own medication methods. AIM OF THE STUDY: To review and conduct meta-analysis of the use of traditional Chinese herbal medicine in treatment of amenorrhea caused by antipsychotic drugs. MATERIALS AND METHODS: A search was conducted across seven Chinese electronic databases (the China National Knowledge Infrastructure (CNKI) database, the China Science and Technology Journal Database, the Wanfang Database, the SinoMed, the Foreign Medical Literature Retrieval Service(FMRS), the Chinese University of Hong Kong Library, the Airiti Library), and the following English databases: MEDLINE, PreMEDLINE, OLD MEDLINE、Publisher Supplied Citation in pubmed; JBI EBP Database, EBM Reviews, Embase, OVID Emcare, Ovid MEDLINE(R), Maternity & Infant Care Database(MIDIRS), APA PsycInfo in OVID, and Cochrane Database of Systematic Reviews (Cochrane Reviews), Database of Abstracts of Reviews of Effects (Other Reviews), Cochrane Central Register of Controlled Trials (Clinical Trials),The Cochrane Methodology Register (Method Studies), Health Technology Assessment Database (Technology Assessments), NHS Economic Evaluation Database (Economic Evaluations) in Cochrane Library; and four databases (Science Direct, ProQuest, Web of Science, and Scopus) in official website using common standards and inclusion/exclusion criteria. The remaining reports were used for preliminary studies. Due to inconsistencies in control groups, randomized controlled trials and articles that combined with other drugs were also excluded. This study is a META analysis of a single rate. RESULTS: Initial screening returned 912 potentially relevant publications in all databases. After subsequent filtering, a total of 18 articles were included in the analysis. The overall effectiveness for treatment amenorrhea caused by antipsychotic drugs using traditional Chinese herbal medicine was 0.91, with 95% confidence interval of 0.89-0.93. Notably in most studies, the time needed to achieve this level of effectiveness was relatively long, usually in excess of three months. Although a satisfactory verification of an improvement in menstrual cycling takes time, the long treatment duration is a downside. Our analysis revealed that the following Chinese herbal remedies were most common: Danggui (Angelica sinensis (Oliv.) Diels), Chuanxiong (Ligusticum striatum DC.), Taoren (Prunus persica (L.) Batsch), Honghua (Carthamus tinctorius L.), Gancao (Glycyrrhiza uralensis Fisch.), Fuling ((Fungus) Poria cocos (Schw.) Wolf), Baizhu (Atractylodes macrocephala Koidz.), Xiangfu (Cyperus rotundus L.), Chaihu (Bupleurum chinense DC.), Shudihuang (Rehmannia glutinosa (Gaertn.) DC.(Processed), Baishao (Cynanchum otophyllum C.K.Schneid.) CONCLUSIONS: Chinese herbal medicine can effectively treat amenorrhea caused by psychiatric drugs, although it takes a long time to achieve satisfactory effectiveness. More research is needed to better understand different aspects of Chinese herbal medicine use in treatment of this particular medical condition.

TRIM59 promotes osteosarcoma progression via activation of STAT3.

Osteosarcoma (OS) is a common, highly malignant bone tumor. Tripartite motif-containing protein 59 (TRIM59) has been identified as a potential oncogenic protein involved in the initiation and progression of various human carcinomas. Nonetheless, the possible roles and molecular mechanisms of action of TRIM59 in OS remain unclear. In this study, we found that TRIM59 expression levels were frequently upregulated in OS tissues and cell lines. TRIM59 knockdown significantly suppressed the proliferation, migration, and invasion of OS cells and promoted OS cell apoptosis, whereas TRIM59 overexpression had the opposite effects. In vivo experiments demonstrated that TRIM59 knockdown suppressed OS tumor growth and metastasis in vivo. Furthermore, we found that TRIM59 directly interacted with phospho-STAT3 in OS cells. The downregulation of STAT3 levels attenuated TRIM59-induced cell proliferation and invasion. Taken together, our results indicate that TRIM59 promoted OS progression via STAT3 activation. Therefore, our study may provide a novel therapeutic target for OS.

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.

Tissue Engineering Strategies for Peripheral Nerve Regeneration.

A peripheral nerve injury (PNI) has severe and profound effects on the life of a patient. The therapeutic approach remains one of the most challenging clinical problems. In recent years, many constructive nerve regeneration schemes are proposed at home and abroad. Nerve tissue engineering plays an important role. It develops an ideal nerve substitute called artificial nerve. Given the complexity of nerve regeneration, this review summarizes the pathophysiology and tissue-engineered repairing strategies of the PNI. Moreover, we discussed the scaffolds and seed cells for neural tissue engineering. Furthermore, we have emphasized the role of 3D printing in tissue engineering.

Application of modified mini-clinical evaluation exercise in the cultivation of orthopaedic students.

OBJECTIVE: To apply the mini-clinical evaluation exercise (Mini-CEX) to orthopaedics and check its influence on clinical operational abilities and thinking abilities. METHODS: The original Mini-CEX was modified to fit orthopaedics, and another Mini-CEX was established to test interns' clinical operational abilities. A total of 39 interns had to complete two types of Mini-CEX twice, once at the beginning and once at the end of the internship. Clinical supervisors collected all the scores and analysed the differences in the average scores between the first and second assessments. The interns were divided into Qualified teacher group and Excellent teacher group according to their Mini-CEX scores. RESULTS: The results of the Mini-CEX examination of the two groups were compared. Researchers found a significant difference between the two assessments on seven domains (all P < 0.05). The scores at the end were higher than those at the beginning, which indicated that the interns' clinical thinking and operational abilities had improved. The average scores of the interns in the Excellent teacher group were significantly higher than those of interns in the Qualified teacher group. CONCLUSIONS: The modified Mini-CEX is suitable for orthopaedic education and could help cultivate interns' clinical thinking ability.

Development and Application of 3D Bioprinted Scaffolds Supporting Induced Pluripotent Stem Cells.

Three-dimensional (3D) bioprinting is a revolutionary technology that replicates 3D functional living tissue scaffolds in vitro by controlling the layer-by-layer deposition of biomaterials and enables highly precise positioning of cells. With the development of this technology, more advanced research on the mechanisms of tissue morphogenesis, clinical drug screening, and organ regeneration may be pursued. Because of their self-renewal characteristics and multidirectional differentiation potential, induced pluripotent stem cells (iPSCs) have outstanding advantages in stem cell research and applications. In this review, we discuss the advantages of different bioinks containing human iPSCs that are fabricated by using 3D bioprinting. In particular, we focus on the ability of these bioinks to support iPSCs and promote their proliferation and differentiation. In addition, we summarize the applications of 3D bioprinting with iPSC-containing bioinks and put forward new views on the current research status.

Evaluation of Interleukin-4-Loaded Sodium Alginate-Chitosan Microspheres for Their Support of Microvascularization in Engineered Tissues.

Defects in the formation of microvascular networks, which provide oxygen and nutrients to cells, are the main reason for the engraftment failure of clinically applicable engineered tissues. Inflammatory responses and immunomodulation can promote the vascularization of the engineered tissues. We developed a capillary construct composed of a gelatin methacrylate-based cell-laden hydrogel framework complexed with interleukin-4 (IL-4)-loaded alginate-chitosan (AC) microspheres and endothelial progenitor cells (EPCs) and RAW264.7 macrophages as model cells. The AC microspheres maintained and guided the EPCs through electrostatic adhesion, facilitating the formation of microvascular networks. The IL-4-loaded microspheres promoted the polarization of the macrophages into the M2 type, leading to a reduction in pro-inflammatory factors and enhancement of the vascularization. Hematoxylin and eosin staining and immunohistochemical analysis revealed that, without IL-4 or AC microspheres, the scaffold was less effective in angiogenesis. We provide an alternative and promising approach for constructing vascularized tissues.

3D bio-printed biphasic scaffolds with dual modification of silk fibroin for the integrated repair of osteochondral defects.

Repair of osteochondral defects is still a challenge, especially the regeneration of hyaline cartilage. Parathyroid hormone (PTH) can inhibit the hypertrophy of chondrocytes to maintain the phenotype of hyaline cartilage. Here, we aimed to construct a bio-printed biphasic scaffold with a mechanical gradient based on dual modification of silk fibroin (SF) for the integrated repair of osteochondral defects. Briefly, SF was grafted with PTH (SF-PTH) and covalently immobilized with methacrylic anhydride (SF-MA), respectively. Next, gelatin methacryloyl (GM) mixed with SF-PTH or SF-MA was used as a bio-ink for articular cartilage and subchondral bone regeneration. Finally, the GM + SF-PTH/GM + SF-MA osteochondral biphasic scaffold was constructed using 3D bioprinting technology, and implanted in a rabbit osteochondral defect model. In this study, the SF-PTH bio-ink was synthesized for the first time. In vitro results indicated that the GM + SF-MA bio-ink had good mechanical properties, while the GM + SF-PTH bio-ink inhibited the hypertrophy of chondrocytes and was beneficial for the production of hyaline cartilage extracellular matrix. Importantly, an integrated GM + SF-PTH/GM + SF-MA biphasic scaffold with a mechanical gradient was successfully constructed. The results in vivo demonstrated that the GM + SF-PTH/GM + SF-MA scaffold could promote the regeneration of osteochondral defects and maintain the phenotype of hyaline cartilage to a large extent. Collectively, our results indicate that the integrated GM + SF-PTH/GM + SF-MA biphasic scaffold constructed by 3D bioprinting is expected to become a new strategy for the treatment of osteochondral defects.

Combining PD-1 Inhibitor with VEGF/VEGFR2 Inhibitor in Chemotherapy: Report of a Patient with End-Stage Cholangiocarcinoma and Review of Literature.

BACKGROUND: Cholangiocarcinoma is the second-largest liver cancer, and develops from the biliary epithelium, where it discretely progresses. Unfortunately, many patients miss the opportunity of performing surgery when diagnosed with cholangiocarcinoma, and due to its chemotherapeutic insensitivity, its control has always been considered difficult. OBJECTIVE: Here, we present a case of stage 4 cholangiocarcinoma being controlled by the combination of chemotherapy with PD-1 and VEGF/VEGFR2 inhibitors. CASE PRESENTATION: The patient is a 58-year-old male who was diagnosed with a progressed cholangiocarcinoma 2 years ago. From the beginning, metastases were discovered in multiple places, and the patient was unsuccessfully treated with 3 chemotherapy regimens. Therefore, a new therapeutic method was considered, and that involved the testing of a new combination of chemotherapy with PD-1 and VEGF/VEGFR2 inhibitors. RESULTS: After 6 courses of treatment with this combination, the patient's lesions became smaller and stable. CONCLUSION: Our case highlights the possibility of combining chemotherapy with PD-1 and VEGF/ VEGFR2 inhibitors for the treatment of cholangiocarcinoma patients. This combination may herald new hope for patients who run out of regimens.

Three-dimensional bioprinting of multicell-laden scaffolds containing bone morphogenic protein-4 for promoting M2 macrophage polarization and accelerating bone defect repair in diabetes mellitus.

Critical-sized bone defect repair in patients with diabetes mellitus remains a challenge in clinical treatment because of dysfunction of macrophage polarization and the inflammatory microenvironment in the bone defect region. Three-dimensional (3D) bioprinted scaffolds loaded with live cells and bioactive factors can improve cell viability and the inflammatory microenvironment and further accelerating bone repair. Here, we used modified bioinks comprising gelatin, gelatin methacryloyl (GelMA), and 4-arm poly (ethylene glycol) acrylate (PEG) to fabricate 3D bioprinted scaffolds containing BMSCs, RAW264.7 macrophages, and BMP-4-loaded mesoporous silica nanoparticles (MSNs). Addition of MSNs effectively improved the mechanical strength of GelMA/gelatin/PEG scaffolds. Moreover, MSNs sustainably released BMP-4 for long-term effectiveness. In 3D bioprinted scaffolds, BMP-4 promoted the polarization of RAW264.7 to M2 macrophages, which secrete anti-inflammatory factors and thereby reduce the levels of pro-inflammatory factors. BMP-4 released from MSNs and BMP-2 secreted from M2 macrophages collectively stimulated the osteogenic differentiation of BMSCs in the 3D bioprinted scaffolds. Furthermore, in calvarial critical-size defect models of diabetic rats, 3D bioprinted scaffolds loaded with MSNs/BMP-4 induced M2 macrophage polarization and improved the inflammatory microenvironment. And 3D bioprinted scaffolds with MSNs/BMP-4, BMSCs, and RAW264.7 cells significantly accelerated bone repair. In conclusion, our results indicated that implanting 3D bioprinted scaffolds containing MSNs/BMP-4, BMSCs, and RAW264.7 cells in bone defects may be an effective method for improving diabetic bone repair, owing to the direct effects of BMP-4 on promoting osteogenesis of BMSCs and regulating M2 type macrophage polarization to improve the inflammatory microenvironment and secrete BMP-2.

Bifunctional, Copper-Doped, Mesoporous Silica Nanosphere-Modified, Bioceramic Scaffolds for Bone Tumor Therapy.

In the traditional surgical intervention procedure, residual tumor cells may potentially cause tumor recurrence. In addition, large bone defects caused by surgery are difficult to self-repair. Thus, it is necessary to design a bioactive scaffold that can not only kill residual tumor cells but also promote bone defect regeneration simultaneously. Here, we successfully developed Cu-containing mesoporous silica nanosphere-modified ß-tricalcium phosphate (Cu-MSN-TCP) scaffolds, with uniform and dense nanolayers with spherical morphology via 3D printing and spin coating. The scaffolds exhibited coating time- and laser power density-dependent photothermal performance, which favored the effective killing of tumor cells under near-infrared laser irradiation. Furthermore, the prepared scaffolds favored the proliferation and attachment of rabbit bone marrow-derived mesenchymal stem cells and stimulated the gene expression of osteogenic markers. Overall, Cu-MSN-TCP scaffolds can be considered for complete eradication of residual bone tumor cells and simultaneous healing of large bone defects, which may provide a novel and effective strategy for bone tumor therapy. In the future, such Cu-MSN-TCP scaffolds may function as carriers of anti-cancer drugs or immune checkpoint inhibitors in chemo-/photothermal or immune-/photothermal therapy of bone tumors, favoring for effective treatment.

LncZEB1-AS1 regulates hepatocellular carcinoma bone metastasis via regulation of the miR-302b-EGFR-PI3K-AKT axis.

In patients with hepatocellular carcinoma (HCC), disease progression and associated bone metastasis (BM) can markedly reduce quality of life. While the long non-coding RNA (lncRNA) zinc finger E-box binding homeobox 1 antisense 1 (ZEB1-AS1) has been shown to function as a key regulator of oncogenic processes in HCC and other tumor types, whether it plays a role in controlling HCC BM remains to be established. In the current study, we detected the significant upregulation of lncZEB1-AS1 in HCC tissues, and we found this expression to be associated with BM progression. When we knocked down this lncRNA in HCC cells, we found that this significantly reduced their migratory, invasive, and metastatic activity both in vitro and in vivo. At a mechanistic level, we found that lncZEB1-AS1 was able to target miR-302b and to thereby increase PI3K-AKT pathway activation and EGFR expression, resulting in the enhanced expression of downstream matrix metalloproteinase genes in HCC cells. In summary, our results provide novel evidence that lncZEB1-AS1 can promote HCC BM through a mechanism dependent upon the activation of PI3K-AKT signaling, thus highlighting a potentially novel therapeutic avenue for the treatment of such metastatic progression in HCC patients.

Varisized 3D-Printed Lunate for Kienböck's Disease in Different Stages: Preliminary Results.

OBJECTIVE: To evaluate the feasibility of arthroplasty with varisized three-dimensional(3D) printing lunate prosthesis for the treatment of advanced Kienböck's disease (KD). METHODS: From 2016 November to 2018 September, a retrospective study was performed for the patients of KD in our hospital. Five patients (two males, three females) were included in this study. The mean age of the patients at the time of surgery was 51.6 years (range, 37-64 years). Varisized prosthesis identical to the live model in a ratio of 1:0.85, 1:1, and 1:1.1 were fabricated by 3D printing. All patients (one in Lichtman IIIA stage, two in Lichtman IIIB stage, one in Lichtman IIIC stage, and one in Lichtman IV stage) were treated with lunate excision and 3D printing prosthetic arthroplasty. Visual analog scale score (VAS), the active movement of wrist (extension, flexion) and strength were assessed preoperatively and postoperatively. The Mayo Modified Wrist Score (MMWS), Disabilities of the Arm, Shoulder and Hand (DASH) Score, and patient's satisfaction were evaluated during the follow-up. RESULTS: Prosthesis identical to the live model in a ratio of 1:0.85 or 1:1 were chosen for arthroplasty. The mean operation time (range, 45 to 56 min) was 51.8 ± 4.44 min. Follow-up time ranged from 11 months to 33 months with the mean value of 19.4 months. The mean extension range of the wrist significantly increased from preoperative 44° ± 9.6° to postoperative 60° ± 3.5° (P < 0.05). The mean flexion range of the wrist significantly increased from preoperative 40° ± 10.6° to postoperative 51° ± 6.5° (P < 0.05). The active movement of wrist and strength were improved significantly in all patients. VAS was significantly reduced from 7.3 preoperatively to 0.2 at the follow-up visit (P < 0.05). The mean DASH score was 10 (range, 7.2-14.2), and the mean MMWS was 79 (range, 70-90). There were no incision infection. All patients were satisfied with the treatment. CONCLUSIONS: For patients suffering advanced Kienböck's disease, lunate excision followed by 3D printing prosthetic arthroplasty can reconstruct the anatomical structure of the carpal tunnel, alleviate pain, and improve wrist movement.

Patient-specific Scaffolds with a Biomimetic Gradient Environment for Articular Cartilage-Subchondral Bone Regeneration.

Functional articular repair is known to be hampered by tissue degradation, which occurs in the defective local inflammatory environment that is also characterized by disrupted angiogenesis. The advanced fabrication of scaffolds with designed chemical and physical cues, which provide a biomimetic environment for tissue regeneration, holds considerable promise to circumvent the problem and thus allows functional articular repair. Herein, we developed scaffolds with controllable shapes with hydroxybutyl chitosan (HBC) and oxidized chondroitin sulfate (OCS) hydrogels, whose chemical composition was similar to that of the cartilage extracellular matrix (ECM). By optimizing the concentration of OCS, the functional cross-linker, we achieved a hydrogel promoting proliferation, adhesion, and ECM formation of chondrocytes and inhibiting tube formation of endothelial cells. Using a hydration procedure and bioactivation of mesenchymal stem cells (MSCs), we obtained mesoporous silicate-doped calcium phosphate cement (MS/CPC) scaffolds with a bioactive surface similar to that of bones, with improved osteogenesis and vascularization properties. Personalized cartilage-subchondral repair scaffolds with stable combination were successfully fabricated based on the self-cross-linking properties of the Schiff-based HBC/OCS hydrogel and the macroporous structure of MS/CPC scaffolds with the aid of a 3D printing technique. This study proposes a strategy to design individualized tissue repair biomimetic gradient scaffolds. Further assessments of their osteochondral defect repair properties in vivo should be performed.