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It is of significance to construct the immunomodulatory and osteogenic microenvironment for three dimension (3D) regeneration of bone tissues. 3D scaffolds, with various chemical composition, macroporous structure and surface characteristics offer a beneficial microenvironment for bone tissue regeneration. However, there is a gap between the well-ordered surface microstructure of bioceramic scaffolds and immune microenvironment for bone regeneration. In this study, a gear-inspired 3D scaffold with well-ordered surface microstructure was successfully prepared through a modified extrusion-based 3D printing strategy for immunomodulation and bone regeneration. The prepared gear-inspired scaffolds could induce M2 phenotype polarization of macrophages and further promoted osteogenic differentiation of bone mesenchymal stem cells in vitro. The subsequent in vivo study demonstrated that the gear-inspired scaffolds were able to attenuate inflammation and further promote new bone formation. The study develops a facile strategy to construct well-ordered surface microstructure which plays a key role in 3D immunomodulatory and osteogenic microenvironment for bone tissue engineering and regenerative medicine. • A gear-inspired 3D bioceramic scaffold with highly well-ordered surface microstructure was successfully fabricated through a modified extrusion-based 3D printing technique. • The size and shape of the highly well-ordered microstructure could be readily modulated. • Taking advantage of good inducing effect of the well-ordered microstructure, the gear-inspired scaffold could be used as a satisfactory biomaterial, which could induce M2 phenotype polarization of macrophages and further promoted osteogenic differentiation of bone mesenchymal stem cells in vitro. • The gear-inspired scaffold could construct 3D immunomodulatory microenvironment to significantly attenuate inflammation and further promote new bone formation in vivo. [Display omitted] [ABSTRACT FROM AUTHOR]

Three-dimensional (3D)-printed scaffolds are widely used in tissue engineering to help regenerate critical-sized bone defects. However, conventional scaffolds possess relatively simple porous structures that limit the delivery of oxygen and nutrients to cells, leading to insufficient bone regeneration. Accordingly, in the present study, perfusable and permeable polycaprolactone scaffolds with highly interconnected hollow-pipe structures that mimic natural micro-vascular networks are prepared by an indirect one-pot 3D-printing method. In vitro experiments demonstrate that hollow-pipe-structured (HPS) scaffolds promote cell attachment, proliferation, osteogenesis and angiogenesis compared to the normal non-hollow-pipe-structured scaffolds. Furthermore, in vivo studies reveal that HPS scaffolds enhance bone regeneration and vascularization in rabbit bone defects, as observed at 8 and 12 weeks, respectively. Thus, the fabricated HPS scaffolds are promising candidates for the repair of critical-sized bone defects. [ABSTRACT FROM AUTHOR]

Background. For unicompartmental knee arthroplasty (UKA), accurate alignment of the limb is crucial. This study is aimed at investigating the efficacy and safety of a three-dimensional printed patient-customized guiding template (3DGT) for UKA. Methods. A total of 22 patients receiving UKA were randomly divided into the 3DGT-UKA group (n = 11) and traditional UKA group (T-UKA group; n = 11). In the 3DGT-UKA group, the line and angle of osteotomy were decided on a 3D image of the limb reconstructed from imaging data; a guiding template was then designed and printed out. The patients in the T-UKA group underwent conventional UKA. Prosthesis size, operation time, postoperative drainage, hip–knee angle (HKA), pain, and Hospital for Special Surgery (HSS) scores were recorded at day 1, week 1, month 1, and month 3 after surgery. Results. There was no significant difference in the size of prostheses between the preoperatively designed and actually used in the 3DGT-UKA group (p > 0.05). HKA was comparable in 3DGT-UKA and T-UKA patients. Operation time was shorter (53.6 ± 6.4 minutes vs. 75.8 ± 7.1 minutes) and wound drainage was less (93.2 ± 3.9 mL vs. 85.2 ± 3.0 mL) in 3DGT-UKA than in T-UKA (p < 0.05). Hospital stay was shorter in the 3DGT-UKA group. The 3DGT-UKA group had a lower VAS score on day 1, week 1, and month 1 and a higher HSS score on week 1 and month 1 after surgery. No varus/valgus deformity or prosthesis loosening was observed in either group at the final follow-up. Conclusion. The 3D-printed patient-customized guiding template may help decrease operation time, decrease blood loss, and improve short-term clinical outcomes in patients undergoing UKA surgery. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate the feasibility of an individual navigation template for the deep pin position on the iliac crest, based on digital design and 3D printing technology.Methods: The preoperative CT images of 8 patients with pelvic fractures were collected. The data were reconstructed using a 3D imaging reconstruction workstation. An individual navigation template for the deep pin position on the iliac crest was designed on a virtual 3D model. The individual drill template and the solid pelvic model were produced using the 3D printing technology. The individual drill template was used for intraoperative deep pin position on the iliac crest after the preoperative simulation was completed.Results: Thirty-two external fixator pins were inserted using the individual drill template. The average depth of pins was 84.82 mm. The trajectories were appropriate based on the postoperative X-ray and CT scan. No significant difference in the entry point, convergence angle, and caudal angle of the pins were noted before and after the operation (all P > 0.05). Finite element analysis indicated that the deep external fixator pin position could more reasonably distribute the stress in the cortical and spongy bones in the pelvis. All patients could perform partial weight-bearing activity 6 weeks postoperatively. No loosening and rupture of the pin, infection, and no damage of blood vessels and nervous tissue were found during the entire follow-up period.Conclusions: The individual drill template technique is an improvement of the traditional technique, which could increase precision and the depth of pin position. In addition, good mechanical stability and low risk of pin-related complications occurred due to the individual drill template, which makes the external fixation technique a potential alternative. [ABSTRACT FROM AUTHOR]

Owing to the different biological properties of articular cartilage and subchondral bone, it remains significant challenge to construct a bi-lineage constructive scaffold. In this study, manganese (Mn)-doped β-TCP (Mn-TCP) scaffolds with varied Mn contents are prepared by a 3D-printing technology. The effects of Mn on the physicochemical properties, bioactivity, and corresponding mechanism for stimulating osteochondral regeneration are systematically investigated. The incorporation of Mn into β-TCP lowers the lattices parameters and crystallization temperatures, but improves the scaffold density and compressive strength. The ionic products from Mn-TCP significantly improve the proliferation of both rabbit chondrocytes and mesenchymal stem cells (rBMSCs), as well as promote the differentiation of chondrocytes and rBMSCs. The in vivo study shows that Mn-TCP scaffolds distinctly improve the regeneration of subchondral bone and cartilage tissues as compared to TCP scaffolds, upon transplantation in rabbit osteochondral defects for 8 and 12 weeks. The mechanism is closely related to the Mn2+ ions significantly stimulated the proliferation and differentiation of chondrocytes through activating HIF pathway and protected chondrocytes from the inflammatory osteoarthritis environment by activating autophagy. These findings suggest that 3D-printing of Mn-containing scaffolds with improved physicochemical properties and bilineage bioactivities represents an intelligent strategy for regenerating osteochondral defects. [ABSTRACT FROM AUTHOR]

Adv. Funct. Mater.2017, 27, 1703117 DOI: 10.1002/adfm.201703117 The above article, first published online on 31 July 2017 in Wiley Online Library (https://doi.org/10.1002/adfm.201703117) and corrected on 19 March 2019 (https://doi.org/10.1002/adfm.201900376) has been retracted by agreement with the authors, the journal Editor‐in‐Chief, and Wiley‐VCH Verlag GmbH & Co. KGaA. The retraction has been agreed upon due to several flawed figures as published in the article, containing duplicate images, which calls the validity of these data into question. Reference C. Deng, Q. Yao, C. Feng, J. Li, L. Wang, G. Cheng, M. Shi, L. Chen, J. Chang, C. Wu, Adv. Funct. Mater.2017, 27, 1703117. [ABSTRACT FROM AUTHOR]

The lack of traditional bioactivity in zirconia (ZrO 2) and limitations in the personalization capabilities of conventional manufacturing processes pose significant challenges for alveolar bone defect repair. This study aims to investigate whether ZrO 2 /CSi-Mgx scaffolds, produced by combining magnesium-doped calcium silicate (CSi–Mg) as a doping phase with ZrO 2 as the matrix, using projection-based 3D printing (3DPP) technology, exhibit favorable biocompatibility and mechanical properties at low sintering temperatures. The effect of CSi–Mg content (x%), pore structure and heating temperature on the strength of scaffolds were investigated systematically. Incorporation of CSi–Mg could readily adjust the sintering properties of the ZrO 2 scaffolds and the scaffolds with low (10–20 %) CSi–Mg possess much higher strength (74–92 MPa) after 1150 °C. Meanwhile, the ZrO 2 /CSi–Mg10 scaffolds with Triply periodic minimum surfaces (TPMS) pore structure had a compression strength of over 92 MPa and maintained a respectable strength (63 MPa) even after immersion in Tris buffer for 6 weeks. Concurrently, cellular experiments showed that incorporation of CSi–Mg could enhance cellular adhesion, proliferation, and migration of the ZrO 2 scaffolds and also promote the osteogenic property of the scaffolds. In conclusion, the ZrO 2 /CSi–Mg10 scaffold with TPMS pore structure showcases remarkable mechanical performance and bioactivity, holding the potential to facilitate in-situ bone regeneration within the alveolar bone. [ABSTRACT FROM AUTHOR]

Abstract It is difficult to achieve self-healing outcoming for the osteochondral defects caused by degenerative diseases. The simultaneous regeneration of both cartilage and subchondral bone tissues is an effective therapeutic strategy for osteochondral defects. However, it is challenging to design a single type of bioscaffold with suitable ionic components and beneficial osteo/chondral-stimulation ability for regeneration of osteochondral defects. In this study, we successfully synthesized a pure-phase lithium calcium silicate (Li 2 Ca 4 Si 4 O 13 , L 2 C 4 S 4) bioceramic by a sol-gel method, and further prepared L 2 C 4 S 4 scaffolds by using a 3D-printing method. The compressive strength of L 2 C 4 S 4 scaffolds could be well controlled in the range of 15–40 MPa when pore size varied from 170 to 400 μm. L 2 C 4 S 4 scaffolds have been demonstrated to possess controlled biodegradability and good apatite-mineralization ability. At a certain concentration range, the ionic products from L 2 C 4 S 4 significantly stimulated the proliferation and maturation of chondrocytes, as well as promoted the osteogenic differentiation of rBMSCs. L 2 C 4 S 4 scaffolds simultaneously promoted the regeneration of both cartilage and subchondral bone as compared to pure β-TCP scaffolds in rabbit osteochondral defects. These findings suggest that 3D-printed L 2 C 4 S 4 scaffolds with such specific ionic combination, high mechanical strength and good degradability as well as dual bioactivities, represent a promising biomaterial for osteochondral interface reconstruction. Graphical abstract 3D-printed Li 2 Ca 4 Si 4 O 13 scaffolds possess dual bioactivities and can biologically fulfill the requirements of both cartilage and subchondral bone interface reconstruction, which represents a feasible strategy for osteochondral reconstruction. Image 1 [ABSTRACT FROM AUTHOR]

[Display omitted] • Customized magnesium-doped wollastonite/nano-hydroxyapatite bioceramic scaffolds with precise porous structures were fabricated by 3D printing and coating technique. • Composite bioceramic scaffold with 15 μm coating thickness exhibited the highest mechanical properties. • Nano-hydroxyapatite coating can effectively inhibite the proliferation of human osteosarcoma cells. • Composite bioceramic scaffold had significantly enhanced osteogenic induction on Rat bone marrow stem cells. It is still a major challenge to remove tumor cells and fill bone defects after tumor resection. Combined with the 3D printing technology, the composite bioceramics scaffolds were fabricated with interconnected porous magnesium-doped wollastonite (CSi-Mg) scaffolds as the architecture and nano-hydroxyapatite (n -HA) as the surface. The influence of manufacturing process on the n -HA layer thickness and degradation performance, biological performance and anti-tumor performance of the composite scaffolds were investigated. The n -HA surface layer could effectively retard the degradation rate of CSi-Mg scaffolds and maintain high mechanical strength (over 90 MPa) after immersion in simulated body fluid for 3 weeks. Meanwhile, CSi-Mg/n-HA3 scaffold induced about 50 % of cell death for human osteosarcoma cells (MG-63) in vitro. CSi-Mg/ n -HAx (x = 1, 3) scaffolds could improve the osteogenic performance of Rat BMSC. These findings demonstrate that the bioceramic composite scaffold with high strength, good osteogenic performance and anti-tumor performance is promising for the treatment of tissue injury after resection of osteosarcoma. [ABSTRACT FROM AUTHOR]