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Void fillers are required for osseous gaps generated after orthopedic procedures as medial open-wedge high-tibial osteotomy (MOWHTO) to provide sufficient structural support and a rapid osteosynthesis. We developed a novel three-dimensional (3D) printing-based platform technology using the customized 3D scaffolds covered with polycaprolactone (PCL)/β-tri-calcium phosphates (β-TCP)/bone decellularized extracellular matrix (dECM) for use as bone substitute scaffold, which can be effectively exploited to estimate the calculated correction angle with preoperative simulations. PCL/β-TCP/bone dECM scaffolds demonstrated significantly higher cell contain levels in cell seeding efficiency, excellent proliferation capacity, and promotion of early osteogenic differentiation compared with PCL/β-TCP scaffolds. The scaffolds promoted bone mineralization at the early time points of an in vivo study (8 weeks) and exhibited biodegradable properties (38% for 16 weeks). The correction angle measured after osteotomy using 3D printed scaffolds was estimated with high accuracy with low errors (10.3° ± 0.9°) and was not significantly different even in the presence of lateral cortical hinge fractures. The customized 3D scaffold enriched with PCL/β-TCP/bone dECM yielded excellent cell seeding efficiency, proliferation capacity, early osteogenic differentiation, and bone mineralization outcomes. It is expected to solve the disadvantages related to bone union in MOWHTO and to replace autografts in the future. [ABSTRACT FROM AUTHOR]

The inferomedial orbital strut (IOS) is the thin bony junction of the orbital medial wall and floor. Its fracture is common and leads to serious complications, including enophthalmos, globe dystopia and diplopia. However, anatomical restoration of the IOS is challenging owing to reduced structural support; sound anatomical background and accurate implants are therefore essential. The aim of the present study was to incorporate data from cadaveric orbit anatomy into three‐dimensional (3D) printing technology and to reconstruct the complex orbital fracture elaborately. After averaging the data from computed tomography (CT) images of 100 adult cadavers, the dimensions of the IOS were extracted, and a tangent sphere was created using a computer‐aided design program. The curves were compared with the CT data of 10 adult patients from the simulation test. Based on these data, a standardized 3D implant, 1.15 mm thick, was designed using polycaprolactone. The implant was placed in five patients with complex orbital fractures. The radius of the sphere in contact with the orbit, measuring 33.54 mm, was confirmed to be appropriate. A comparison between the normal side volume (V0) and the postoperative volume (Vpost) showed that they were statistically similar. Furthermore, a comparison between V0 and the preoperative volume (Vpre), and Vpost compared with Vpre also showed a statistically significant difference (P < 0.05). On follow‐up, the preoperative ocular symptoms were resolved. The orbital data obtained from 100 cadavers provided standardized orbital anatomy, and 3D printed implants were created. The implants were anatomically accurate with regard to the orbital cavity and adequately covered the simulation model. The implant also showed satisfactory results when applied clinically in actual patients. [ABSTRACT FROM AUTHOR]

Upon bioprinting, cells are mixed with a biomaterial to fabricate a living tissue, thus emphasizing the importance of biomaterials. The biomaterial used in this study was a bio-ink prepared using skin decellularized extracellular matrix (dECM). Skin dECM was extracted by treating the dermis with chemicals and enzymes; the basic structural and functional proteins of the ECM, including collagen, glycosaminoglycans (GAGs), bioreactive materials and growth factors, were preserved, whereas the resident cells that might cause immune rejection or inflammatory responses were removed. The bio-ink based on dECM powder, together with human dermal fibroblasts (HDFs), was loaded into the nozzle of the 3D bioprinter to create the 3D construct. This construct underwent gelation with changing temperature while its shape was maintained for 7 days. The cells showed over 90% viability and proliferation. By analysing the gene expression pattern in the cells of the construct, the skin regenerative mechanism of the bio-ink was verified. Microarray results confirmed that the gene expression related to skin morphology and development had been enhanced because the bioreactive molecules and growth factors, in addition to residual ECM in dECM, provided an optimal condition for the HDFs. [ABSTRACT FROM AUTHOR]

Ear reconstruction using three‐dimensional (3D) printing technique has been considered as a good substitute for conventional surgery, because it can provide custom‐made 3D framework. However, there are difficulties with its application in clinical use. Researchers have reported 3D scaffolds for ear cartilage regeneration, but the designs of the 3D scaffolds were not appropriate to be used in surgery. Hence, we propose the design of an ideal 3D ear scaffold for use in ear reconstruction surgery. Facial computed tomography (CT) images of the unaffected ear were extracted using a "segmentation" procedure. The selected data were converted to a 3D model and mirrored to create a model of the affected side. The design of 3D model was modified to apply to Nagata's two‐stage surgery. Based on the 3D reconstructed model, a 3D scaffold was 3D printed using polycaprolactone. The 3D scaffold closely resembled the real cartilage framework used in current operations in terms of ear anatomy. To account for skin thickness, the 3D scaffold was made 4 mm smaller than the real ear. Furthermore, 2 mm pores were included to allow the implantation of diced cartilage to promote regeneration of the cartilage. 3D printing technology can overcome the limitations of previous auricular reconstruction methods. Further studies are required to achieve a functional and stable substitute for auricular cartilage and to extend the clinical use of the 3D‐printed construct. Additionally, the ethical and legal issues regarding the transplantation of 3D‐printed constructs and cell culture technologies using human stem cells remain to be solved. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1295–1303, 2019. [ABSTRACT FROM AUTHOR]

This study was undertaken to evaluate the effect of 3D printed polycaprolactone (PCL)/β-tricalcium phosphate (β-TCP) scaffold containing bone demineralized and decellularized extracellular matrix (bdECM) and human recombinant bone morphogenetic protein-2 (rhBMP-2) on bone regeneration. Scaffolds were divided into PCL/β-TCP, PCL/β-TCP/bdECM, and PCL/β-TCP/bdECM/BMP groups. In vitro release kinetics of rhBMP-2 were determined with respect to cell proliferation and osteogenic differentiation. These three reconstructive materials were implanted into 8 mm diameter calvarial bone defect in male Sprague-Dawley rats. Animals were sacrificed four weeks after implantation for micro-CT, histologic, and histomorphometric analyses. The findings obtained were used to calculate new bone volumes (mm3) and new bone areas (%). Excellent cell bioactivity was observed in the PCL/β-TCP/bdECM and PCL/β-TCP/bdECM/BMP groups, and new bone volume and area were significantly higher in the PCL/β-TCP/bdECM/BMP group than in the other groups (p<.05). Within the limitations of this study, bdECM printed PCL/β-TCP scaffolds can reproduce microenvironment for cells and promote adhering and proliferating the cells onto scaffolds. Furthermore, in the rat calvarial defect model, the scaffold which printed rhBMP-2 loaded bdECM stably carries rhBMP-2 and enhances bone regeneration confirming the possibility of bdECM as rhBMP-2 carrier. [ABSTRACT FROM AUTHOR]

Surgical technique using autologs cartilage is considered as the best treatment for cartilage tissue reconstruction, although the burdens of donor site morbidity and surgical complications still remain. The purpose of this study is to apply three-dimensional (3D) cell printing to fabricate a tissue-engineered graft, and evaluate its effects on cartilage reconstruction. A multihead tissue/organ building system is used to print cell-printed scaffold (CPS), then assessed the effect of the CPS on cartilage regeneration in a rabbit ear. The cell viability and functionality of chondrocytes were significantly higher in CPS than in cell-seeded scaffold (CSS) and cell-seeded hybrid scaffold (CSHS) in vitro. CPS was then implanted into a rabbit ear that had an 8 mm-diameter cartilage defect; at 3 months after implantation the CPS had fostered complete cartilage regeneration whereas CSS and autologs cartilage (AC) fostered only incomplete healing. This result demonstrates that cell printing technology can provide an appropriate environment in which encapsulated chondrocytes can survive and differentiate into cartilage tissue in vivo. Moreover, the effects of CPS on cartilage regeneration were even better than those of AC. Therefore, we confirmed the feasibility of CPS as an alternative to AC for auricular reconstruction. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1016-1028, 2017. [ABSTRACT FROM AUTHOR]

Objectives Polycaprolactone (PCL) is an U.S. Food and Drug Administration-approved synthetic biodegradable polymer and is easily fabricated into three-dimensional (3D) structures. In this study, the 3D-printed PCL implant for nasal augmentation was further evaluated for its suitability for nasal surgeries such as septoplasty and rhinoplasty. Methods Ten New Zealand White rabbits were included and divided into study and sham groups (7 and 3, respectively). A lateral incision was made on the nasal dorsum and a pocket formed in the subperichondrial plane between the upper lateral cartilage and nasal septum. Polycaprolactone was fabricated based on 3D printing technology into a 0.8 × 0.8-cm rectangular shape for use as a nasal implant. The material was inserted as a septal extension graft and sutured with alar cartilage for nasal reshaping. The implants were harvested 4, 8, and 12 weeks after implantation and evaluated by gross morphological assessment and histological examination. Results The initial shape of the implant was unchanged in all cases, and no definitive postoperative complications were seen over the 3-month period. Gross morphological evaluation confirmed that implants remained in their initial location without migration or extrusion. Histologic evaluations showed that the implant architectures were maintained with excellent fibrovascular ingrowth and minimal inflammatory reactions. Conclusion Polycaprolactone can be used for nasal reconstruction such as nasal augmentation. Polycaprolactone is easy to work with and will avoid the increased operative time and morbidity associated with autograft harvesting. Therefore, PCL implants designed by 3D printing can serve as clinically biocompatible materials in craniofacial reconstruction in the future. Level of Evidence NA. Laryngoscope, 127:1036-1043, 2017 [ABSTRACT FROM AUTHOR]

When large engineered tissue structures are used to achieve tissue regeneration, formation of vasculature is an essential process. We report a technique that combines 3D printing with spatial and temporal control of dual growth factors to prevascularize bone tissue. Human dental pulp stem cells (DPSCs) that have both osteogenic and vasculogenic potential were printed with bone morphogenetic protein-2 (BMP-2) in the peripheral zone of the 3D printed construct, and with the vascular endothelial growth factor (VEGF) in the central zone, in which a hypoxic area forms. The structure was implanted in the back of a mouse and tissue regeneration was assessed after 28 d. Microvessels were newly formed in the hypoxic area of the printed large volume structure, and angiogenesis from the host tissue was also observed. Bone regeneration was faster in prevascularized structures than in nonvascularized structures. The 3D-printed prevascularized structure could be a promising approach to overcome the size limitation of tissue implants and to enhance bone regeneration. [ABSTRACT FROM AUTHOR]

Fabrication of a three-dimensional (3D) scaffold with increased mechanical strength may be an essential requirement for more advanced bone tissue engineering scaffolds. Various material- and chemical-based approaches have been explored to enhance the mechanical properties of engineered bone tissue scaffolds. In this study, the effects of pore architecture and stacking direction on the mechanical and cell proliferation properties of a scaffold were investigated. The 3D scaffold was prepared using solid freeform fabrication technology with a multihead deposition system. Various types of scaffolds with different pore architectures (lattice, stagger, and triangle types) and stacking directions (horizontal and vertical directions) were fabricated with a blend of polycaprolactone and poly lactic-co-glycolic acid. In compression tests, the triangle-type scaffold was the strongest among the experimental groups. Stacking direction affected the mechanical properties of scaffolds. An in vitro cell counting kit-8 assay showed no significant differences in optical density depending on the different pore architectures and stacking directions. In conclusion, mechanical properties of scaffolds can be enhanced by controlling pore architecture and stacking direction. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012. [ABSTRACT FROM AUTHOR]

(1) Background: In the present study, we evaluated the efficacy of a 3D-printed, patient-specific polycaprolactone/beta tricalcium phosphate (PCL/β-TCP) scaffold in the treatment of complex zygomatico-maxillary defects. (2) Methods: We evaluated eight patients who underwent immediate or delayed maxillary reconstruction with patient-specific PCL implants between December 2019 and June 2021. The efficacy of these techniques was assessed using the volume and density analysis of computed tomography data obtained before surgery and six months after surgery. (3) Results: Patients underwent maxillary reconstruction with the 3D-printed PCL/β-TCP scaffold based on various reconstructive techniques, including bone graft, fasciocutaneous free flaps, and fat graft. In the volume analysis, satisfactory volume conformity was achieved between the preoperative simulation and actual implant volume with a mean volume conformity of 79.71%, ranging from 70.89% to 86.31%. The ratio of de novo bone formation to total implant volume (bone volume fraction) was satisfactory with a mean bone fraction volume of 23.34%, ranging from 7.81% to 66.21%. Mean tissue density in the region of interest was 188.84 HU, ranging from 151.48 HU to 291.74 HU. (4) Conclusions: The combined use of the PCL/β-TCP scaffold with virtual surgical simulation and 3D printing techniques may replace traditional non-absorbable implants in the future owing to its accuracy and biocompatible properties. [ABSTRACT FROM AUTHOR]

Bone formation and growth are crucial for treating bone fractures. Improving bone-reconstruction methods using autologous bone and synthetic implants can reduce the recovery time. Here, we investigated three treatments using two different materials, a bone-derived decellularized extracellular matrix (bdECM) and β-tricalcium phosphate (β-TCP), individually and in combination, as osteogenic promoter between bone and 3D-printed polycaprolactone scaffold (6-mm diameter) in rat calvarial defects (8-mm critical diameter). The materials were tested with a human pre-osteoblast cell line (MG63) to determine the effects of the osteogenic promoter on bone formation in vitro. A polycaprolactone (PCL) scaffold with a porous structure was placed at the center of the in vivo rat calvarial defects. The gap between the defective bone and PCL scaffold was filled with each material. Animals were sacrificed four weeks post-implantation, and skull samples were preserved for analysis. The preserved samples were scanned by micro-computed tomography and analyzed histologically to examine the clinical benefits of the materials. The bdECM–β-TCP mixture showed faster bone formation and a lower inflammatory response in the rats. Therefore, our results imply that a bdECM–β-TCP mixture is an ideal osteogenic promoter for treating fractures. [ABSTRACT FROM AUTHOR]

The three-dimensional (3D) cell-printing technique has been identified as a new biofabrication platform because of its ability to locate living cells in pre-defined spatial locations with scaffolds and various growth factors. Osseointegrated dental implants have been regarded as very reliable and have long-term reliability. However, host defense mechanisms against infections and micro-movements have been known to be impaired around a dental implant because of the lack of a periodontal ligament. In this study, we fabricated a hybrid artificial organ with a periodontal ligament on the surface of titanium using 3D printing technology. CEMP-1, a known cementogenic factor, was enhanced in vitro. In animal experiments, when the hybrid artificial organ was transplanted to the calvarial defect model, it was observed that the amount of connective tissue increased. 3D-printed hybrid artificial organs can be used with dental implants, establishing physiological tooth functions, including the ability to react to mechanical stimuli and the ability to resist infections. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) printing is perceived as an innovative tool for change in tissue engineering and regenerative medicine based on research outcomes on the development of artificial organs and tissues. With advances in such technology, research is underway into 3D-printed artificial scaffolds for tissue recovery and regeneration. In this study, we fabricated artificial scaffolds by coating bone demineralized and decellularized extracellular matrix (bdECM) onto existing 3D-printed polycaprolactone/tricalcium phosphate (PCL/TCP) to enhance osteoconductivity and osteoinductivity. After injecting adipose-derived stem cells (ADSCs) in an aggregate form found to be effective in previous studies, we examined the effects of the scaffold on ossification during mandibular reconstruction in beagle dogs. Ten beagles were divided into two groups: group A (PCL/TCP/bdECM + ADSC injection; n = 5) and group B (PCL/TCP/bdECM; n = 5). The results were analyzed four and eight weeks after intervention. Computed tomography (CT) findings showed that group A had more diffuse osteoblast tissue than group B. Evidence of infection or immune rejection was not detected following histological examination. Goldner trichrome (G/T) staining revealed rich ossification in scaffold pores. ColI, Osteocalcin, and Runx2 gene expressions were determined using real-time polymerase chain reaction. Group A showed greater expression of these genes. Through Western blotting, group A showed a greater expression of genes that encode ColI, Osteocalcin, and Runx2 proteins. In conclusion, intervention group A, in which the beagles received the additional ADSC injection together with the 3D-printed PCL/TCP coated with bdECM, showed improved mandibular ossification in and around the pores of the scaffold. [ABSTRACT FROM AUTHOR]