ObjectiveTo explore the effectiveness of a new point contact pedicle navigation template (referred to as “new navigation template” for simplicity) in assisting screw implantation in scoliosis correction surgery. MethodsTwenty-five patients with scoliosis, who met the selection criteria between February 2020 and February 2023, were selected as the trial group. During the scoliosis correction surgery, the three-dimensional printed new navigation template was used to assist in screw implantation. Fifty patients who had undergone screw implantation with traditional free-hand implantation technique between February 2019 and February 2023 were matched according to the inclusion and exclusion criteria as the control group. There was no significant difference between the two groups (P>0.05) in terms of gender, age, disease duration, Cobb angle on the coronal plane of the main curve, Cobb angle at the Bending position of the main curve, the position of the apical vertebrae of the main curve, and the number of vertebrae with the pedicle diameter lower than 50%/75% of the national average, and the number of patients whose apical vertebrae rotation exceeded 40°. The number of fused vertebrae, the number of pedicle screws, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were compared between the two groups. The occurrence of implant complications was observed. Based on the X-ray films at 2 weeks after operation, the pedicle screw grading was recorded, the accuracy of the implant and the main curvature correction rate were calculated. ResultsBoth groups successfully completed the surgeries. Among them, the trial group implanted 267 screws and fused 177 vertebrae; the control group implanted 523 screws and fused 358 vertebrae. There was no significant difference between the two groups (P>0.05) in terms of the number of fused vertebrae, the number of pedicle screws, the pedicle screw grading and accuracy, and the main curvature correction rate. However, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were significantly lower in trial group than in control group (P<0.05). There was no complications related to screws implantation during or after operation in the two groups. ConclusionThe new navigation template is suitable for all kinds of deformed vertebral lamina and articular process, which not only improves the accuracy of screw implantation, but also reduces the difficulty of operation, shortens the operation time, and reduces intraoperative bleeding.
ObjectiveTo explore the feasibility of three-dimensional (3D) bioprinted adipose-derived stem cells (ADSCs) combined with gelatin methacryloyl (GelMA) to construct tissue engineered cartilage.MethodsAdipose tissue voluntarily donated by liposuction patients was collected to isolate and culture human ADSCs (hADSCs). The third generation cells were mixed with GelMA hydrogel and photoinitiator to make biological ink. The hADSCs-GelMA composite scaffold was prepared by 3D bioprinting technology, and it was observed in general, and observed by scanning electron microscope after cultured for 1 day and chondrogenic induction culture for 14 days. After cultured for 1, 4, and 7 days, the composite scaffolds were taken for live/dead cell staining to observe cell survival rate; and cell counting kit 8 (CCK-8) method was used to detect cell proliferation. The composite scaffold samples cultured in cartilage induction for 14 days were taken as the experimental group, and the composite scaffolds cultured in complete medium for 14 days were used as the control group. Real-time fluorescent quantitative PCR (qRT-PCR) was performed to detect cartilage formation. The relative expression levels of the mRNA of cartilage matrix gene [(aggrecan, ACAN)], chondrogenic regulatory factor (SOX9), cartilage-specific gene [collagen type Ⅱ A1 (COLⅡA1)], and cartilage hypertrophy marker gene [collagen type ⅩA1 (COLⅩA1)] were detected. The 3D bioprinted hADSCs-GelMA composite scaffold (experimental group) and the blank GelMA hydrogel scaffold without cells (control group) cultured for 14 days of chondrogenesis were implanted into the subcutaneous pockets of the back of nude mice respectively, and the materials were taken after 4 weeks, and gross observation, Safranin O staining, Alcian blue staining, and collagen type Ⅱ immunohistochemical staining were performed to observe the cartilage formation in the composite scaffold.ResultsMacroscope and scanning electron microscope observations showed that the hADSCs-GelMA composite scaffolds had a stable and regular structure. The cell viability could be maintained at 80%-90% at 1, 4, and 7 days after printing, and the differences between different time points were significant (P<0.05). The results of CCK-8 experiment showed that the cells in the scaffold showed continuous proliferation after printing. After 14 days of chondrogenic induction and culture on the composite scaffold, the expressions of ACAN, SOX9, and COLⅡA1 were significantly up-regulated (P<0.05), the expression of COLⅩA1 was significantly down-regulated (P<0.05). The scaffold was taken out at 4 weeks after implantation. The structure of the scaffold was complete and clear. Histological and immunohistochemical results showed that cartilage matrix and collagen type Ⅱ were deposited, and there was cartilage lacuna formation, which confirmed the formation of cartilage tissue.ConclusionThe 3D bioprinted hADSCs-GelMA composite scaffold has a stable 3D structure and high cell viability, and can be induced differentiation into cartilage tissue, which can be used to construct tissue engineered cartilage in vivo and in vitro.
Objective To detect the value of three-dimensional (3D) ultrasound diagnosis in common ocular fundus diseases. Methods Two-dimensional (2D) images of 38 patients with common ocular fundus diseases were three-dimensionally reconstructed via 3D ultrasound workstation. The 3D images reflecting the ocular diseases were analyzed. Result In 38 patients with common ocular fundus diseases, there was vitreous hemorrhage in 16 patients, retinal detachment in 12, choroidal detachment in 5, and intraocular space occupying lesion in 5. Compared with the 2D images, 3D reconstructed images reflect the lesions more intuitionistically, displayed the relationship between the lesions and the peripheral tissues more clearly, and revealed the blood flow more specifically. During a scanning examination, 3D reconstructed technology provided the diagnostic information of section of X, Y and Z axises simultaneously which shortened the time of examination; the condition of any point of lesions and the relation between the lesion and the peripheral tissues could be gotten by the tools like cut and chop provided by 3D imaging software itself, which avoided detecting the same lesion with different angles and lays and proved the diagnostic efficacy. Conclusions 3D ultrasound diagnosis is better than 2D in diagnosis of vitreous, retina, choroid, and intraocular space occupying lesion. 3D ultrasound diagnosis is a complementarity for the 2D one, and the Z axis changes the former observational angles which may provide the new way of precise diagnosis. (Chin J Ocul Fundus Dis, 2005, 21: 381-383)
Objective To review the research progress of in-situ three dimensional (3D) bio-printing technology in the repair of bone and cartilage injuries. Methods Literature on the application of in-situ 3D bio-printing technology to repair bone and cartilage injuries at home and abroad in recent years was reviewed, analyzed, and summarized. Results As a new tissue engineering technology, in-situ 3D bio-printing technology is mainly applied to repair bone, cartilage, and skin tissue injuries. By combining biomaterials, bioactive substances, and cells, tissue is printed directly at the site of injury or defect. At present, the research on the technology mainly focuses on printing mode, bio-ink, and printing technology; the application research in the field of bone and cartilage mainly focuses on pre-vascularization, adjusting the composition of bio-ink, improving scaffold structure, printing technology, loading drugs, cells, and bioactive factors, so as to promote tissue injury repair. Conclusion Multiple animal experiments have confirmed that in-situ 3D bio-printing technology can construct bone and cartilage tissue grafts in a real-time, rapid, and minimally invasive manner. In the future, it is necessary to continue to develop bio-inks suitable for specific tissue grafts, as well as combine with robotics, fusion imaging, and computer-aided medicine to improve printing efficiency.
The β-secretase is one of prospective targets against Alzheimer's disease (AD). A three-dimensional quantitative structure-activity relationship (3D-QSAR) model of Hydroethylamines (HEAs) as β-secretase inhibitors was established using Topomer CoMFA. The multiple correlation coefficient of fitting, cross validation and external validation were r2=0.928, qloo2=0.605 and rpred2=0.626, respectively. The 3D-QSAR model was used to search R groups from ZINC database as the source of structural fragments. As a result, a series of R groups with relatively high activity contribution was obtained to design a total of 15 new compounds, with higher activity than that of the template molecule. The molecular docking was employed to study the interaction mode between the new compounds as ligands and β-secretase as receptors, displaying that hydrogen bond and hydrophobicity played important roles in the binding affinity between the new compounds and β-secretase. The results showed that Topomer CoMFA and Topomer Search could be effectively used to screen and design new molecules of HEAs as β-secretase inhibitors, and the designed compounds could provide new candidates for drug design targeting AD.
Tricalcium phosphate (TCP) is one of the most widely used bioceramics for constructing bone tissue engineering scaffold. The three-dimensional (3D) printed TCP scaffold has precise and controllable pore structure, while with the limitation of insufficient mechanical properties. In this study, we investigated the effect of sintering temperature on the mechanical properties of 3D-printed TCP scaffolds in detail, due to the important role of the sintering process on the mechanical properties of bioceramic scaffolds. The morphology, mass and volume shrinkage, porosity, mechanical properties and degradation property of the scaffold was studied. The results showed that the scaffold sintered at 1 150℃ had the maximum volume shrinkage, the minimum porosity and optimal mechanical strength, with the compressive strength of (6.52 ± 0.84) MPa and the compressive modulus of (100.08 ± 18.6) MPa, which could meet the requirements of human cancellous bone. In addition, the 1 150℃ sintered scaffold degraded most slowly in the acidic environment compared to the scaffolds sintered at the other temperatures, demonstrating its optimal mechanical stability over long-term implantation. The scaffold can support bone mesenchymal stem cells (BMSCs) adherence and rapid proliferation and has good biocompatibility. In summary, this paper optimizes the sintering process of 3D printed TCP scaffold and improves its mechanical properties, which lays a foundation for its application as a load-bearing bone.
Three-dimensional (3D) printing is a low-cost, high-efficiency production method, which can reduce the current cost and increase the profitability of skin repair material industry nowadays, and develop products with better performance. The 3D printing technology commonly used in the preparation of skin repair materials includes fused deposition molding technology and 3D bioprinting technology. Fused deposition molding technology has the advantages of simple and light equipment, but insufficient material selection. 3D bioprinting technology has more materials to choose from, but the equipment is cumbersome and expensive. In recent years, research on both technologies has focused on the development and application of materials. This article details the principles of fused deposition modeling and 3D bioprinting, research advances in wound dressings and tissue engineering skin production, and future developments in 3D printing on skin tissue repair, including cosmetic restoration and biomimetic tissue engineering. Also, this review prospects the development of 3D printing technology in skin tissue repairment.
A method of ultrasonic simulation based on the FIELD II software platform for carotid artery plaque was proposed according to the analysis for geometrical shape, tissue characteristics and acoustic properties of carotid artery plaques in clinic, and then a simulation system was developed by using the MATLAB graphical user interface (GUI). In the simulation and development, a three-dimensional geometric model of blood vessel with plaques was set up by using the metaball implicit surface technique, and a tissue model was established based on the scatterers with spatial position of gamma random distribution. Comparison of the statistical and geometrical characteristics from simulated ultrasound B-mode images with those based on clinical ones and preset values, the results fully demonstrated the effectiveness of the simulation methods and system.
Objective To explore the effectiveness of computer-aided technology in the treatment of primary elbow osteoarthritis combined with stiffness under arthroscopy. Methods The clinical data of 32 patients with primary elbow osteoarthritis combined with stiffness between June 2018 and December 2020 were retrospectively analyzed. There were 22 males and 10 females with an average age of 53.4 years (range, 31-71 years). X-ray film and three-dimensional CT examinations showed osteophytes of varying degrees in the elbow joint. Loose bodies existed in 16 cases, and there were 7 cases combined with ulnar nerve entrapment syndrome. The median symptom duration was 2.5 years (range, 3 months to 22.5 years). The location of bone impingement from 0° extension to 140° flexion of the elbow joint was simulated by computer-aided technology before operation and a three-dimensional printed model was used to visualize the amount and scope of impinging osteophytes removal from the anterior and posterior elbow joint to accurately guide the operation. Meanwhile, the effect of elbow joint release and impinging osteophytes removal was examined visually under arthroscopy. The visual analogue scale (VAS) score, Mayo elbow performance score (MEPS), and elbow range of motion (extension, flexion, extension and flexion) were compared between before and after operation to evaluate elbow function. Results The mean operation time was 108 minutes (range, 50-160 minutes). All 32 patients were followed up 9-18 months with an average of 12.5 months. There was no other complication such as infection, nervous system injury, joint cavity effusion, and heterotopic ossification, except 2 cases with postoperative joint contracture at 3 weeks after operation due to the failure to persist in regular functional exercises. Loose bodies of elbow and impinging osteophytes were removed completely for all patients, and functional recovery was satisfactory. At last follow-up, VAS score, MEPS score, extension, flexion, flexion and extension range of motion significantly improved when compared with preoperative ones (P<0.05). Conclusion Arthroscopic treatment of primary elbow osteoarthritis combined with stiffness using computer-aided technology can significantly reduce pain, achieve satisfactory functional recovery and reliable effectiveness.
ObjectiveTo investigate effect of preoperative three-dimensional anorectal endosonography (3D-AREUS) in anal fistula surgery.MethodsA total of 100 patients with anal fistula who were admitted to the Chaoyang Central Hospital from December 2017 to December 2018 were included prospectively, then were randomly divided into ultrasound group and control group with 50 cases in each group. The preoperative examination was performed by 3D-AREUS in the ultrasound group, and preoperative routine examination, finger examination or probe exploration were performed in the control group. The postoperative recurrence and anal functions were compared between the two groups.ResultsThere were no statistically significant differences in the gender, age, body mass index, anal surgery history, preoperative anal function, etc. between the two groups (P>0.05). The detection rate of branch fistulas in the ultrasound group was significantly higher than that in the control group (P=0.025). For the patients with complex anal fistula, compared with the control group, the location accuracy rate of internal opening was higher (P=0.014), the change value of preoperative and postoperative fecal incontinence score was lower (P=0.039), anorectal pressure status (resting pressure of anal canal, anal systolic pressure, and length of anal high pressure zone) were lower (P<0.05) in the ultrasound group; For the patients with simple anal fistula, which had no significant differences between the ultrasound group and control group (P>0.05). There were 4 cases of recurrence in each group.ConclusionsFor complex anal fistula, preoperative 3D-AREUS could clarify position of internal opening, presence of branching fistula, and the relationship between fistula and sphincter, so as to make accurate surgical plans, reduce secondary injuries, and retain postoperative anal function of patients.