Three-dimensional (3D) printing is a rapidly emerging technology that promises to transform tissue engineering into a commercially successful biomedical industry. However, the use of robotic bioprinters alone is not sufficient for disease treatment. This study aimed to report the combined application of 3D scanning and 3D printing for treating bone and cartilage defects. Three different kinds of defect models were created to mimic three orthopedic diseases: large segmental defects of long bones, free-form fracture of femoral condyle, and International Cartilage Repair Society grade IV chondral lesion. Feasibility of in situ 3D bioprinting for these diseases was explored. The 3D digital models of samples with defects and corresponding healthy parts were obtained using high-resolution 3D scanning. The Boolean operation was used to achieve the shape of the defects, and then the target geometries were imported in a 3D bioprinter. Two kinds of photopolymerized hydrogels were synthesized as bioinks. Finally, the defects of bone and cartilage were restored perfectly in situ using 3D bioprinting. The results of this study suggested that 3D scanning and 3D bioprinting could provide another strategy for tissue engineering and regenerative medicine.
In this study, we designed a polyvinyl alcohol (PVA)alginate based hydrogel and evaluated its cytocompatibility and printability. The samples were fabricated by 3D printing using a freeze-thaw process. The scanning electron microscope, material testing machine, rheometer, and cell counting kit-8 assay were used to examine the morphology, mechanical properties, rheological properties, and cytocompatiblity of the scaffolds, respectively. The mechanical strength, cytocompatiblity, crosslinking time, and printability were remarkably improved with the use of PVA. To sum up, our data suggest that hybrid bioink is more appropriate for precise 3D bioprinting due to its rapid prototyping capability and better cytocompatibility.
BackgroundTo explore the therapeutic effect and the biomechanical mechanism of 3D printing individualized heel cup in treating of plantar heel pain.MethodsThe clinical effect was evaluated by plantar pressure analysis and pain assessment in participants. Its biomechanical mechanism of protecting the plantar heel was explored using finite element simulation.ResultsThe individualized heel cup could support and protect the osseous structure and soft tissue of plantar heel while walking and jogging, as well as significantly reduce the self-reported pain after being worn for 4 weeks. The nylon heel cup could alter the load concentration of the heel as well as decrease the load affected on plantar fascia and calcaneus bone. It also provided an obvious support for heel pad.ConclusionTo summarize, the 3D printed individualized heel cup can be used as an effective method for the treatment of plantar heel pain.
Background: The pelvic ring fractures (PRF) are commonly induced by the high-energy impact and will lead to unstable and sever injures. This study is aimed to explore the stability of anterior external fixation in treating pelvis fracture and evaluate the possibility for these kinds of patients to reduce bedridden time.Methods: A patient with Tile B3 pelvis fracture was chosen in the research and the corresponding digital model was reconstructed according to the CT images and 3D scanning. Four angles of pelvis under vertical compression were employed in the finite element (FE) analyses. The stress distribution and micro-motion displacement were calculated to validate the instability of pelvis.Results: The stress applied on the pelvis was ranged from 4.296 to 8.364 MPa in all postures. The stress applied on pins was less than 7.011 MPa during reclining, and reached 28.29 MPa when standing. The micro-motion displacement in reclining posture was ranged from 0.005 to 0.087 mm. The value increased to more than 1mm in standing posture.Conclusions: It was safety for patients with pelvis fracture to sit vertical or recline on the bed during nursing or having treatment, but standing or walking will generate inappropriate micro-motion. The existence of external fixation can reduce the possibility of complications caused by long-term bedridden.
It was aimed to report 5 cases of pharyngeal hairy polyps, and to summarize the characteristics combined with literature review.
Five cases with pathological diagnosis of pharyngeal hair polyps were diagnosed and treated in our department from June, 2006 to October, 2016, and retrospective analysis of their clinical data was performed. Among the 5 cases, there were 1 male and 4 female, with the age of 2 days to 26 months old. After birth, these patients were accompanied by stridor, difficulty breathing, snoring, feeding difficulties, and slow weight gain.
Gray mass in the stem original from the pharynx was found in all 5 cases, with the surface hair-covering. The polyp resections were performed under general anesthesia, with the complete removal of polyp along the pars basilaris during surgery smoothly. The operation during was 5 to 20 minute, with an average of 12 minute, and there was little hemorrhage during operation. Symptoms disappeared completely after the surgery, and follow-up was performed for 1 year without recurrence shown.
Pharyngeal hairy polyp is a rare non-malignant clinical disease, mainly caused by symptoms in respiratory tract obstruction. Complete removal of polyps along the pars basilaris is an effective treatment, with no recurrence case reported after surgery.
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