Objective To investigate the biocompatibility of diamond-like carbon(DLC) coated NickelTitanium shape memory alloy with osteoblasts cultured invitro. Methods Rabbit’s osteoblasts were incubated with DLCcoated NickelTitanium shape memory alloy disks and uncoated ones of equal size for 5 days. The control group（without shape memory alloy in culture media） was performed simultaneously. The cultured cells were counted and graphed. The samples from culture media were collected and the concentrations of alkaline phosphatase (ALP) and nickel（Ni2+） were measured from the 1st to 5th day respectively. Results The proliferation of osteoblasts and the concentration of ALP in both DLC-coated group and control gruop was higher than uncoated group. The proliferation of osteoblasts on the 3rd, 4th, and 5th day in both DLC-coatedgroup and control group was significantly higher than that in the uncoated group(P＜0.05). The concentration of ALP in DLC-coated group on the 2nd, 3rd, and 5th day and in the control group on the 3rd, 4th, and 5th day was significantly higher than that in the uncoated group(P＜0.05). The concentration of Ni2+ on the 3rd, 4th, and 5th day was significantly lower than that in the uncoated group(P＜0.05). Conclusion DLC- coated NickelTitanium shape memory alloys appears to have better biocompatibility with osteoblast cultured in vitro compared to uncoated ones.
Objective To compare the clinical effects of treating prolapse of the cervical intervertebral disc by the Solis cage fusion, the titanium cage fusion or the autogenous iliac crest graft combined with the titanium plate fixation. Methods Sixty-four patients with prolapse of the cervical intervertebral discadmitted to hospital from February 2002 to May 2005 were retrospectively analyzed. In Group A, 20 patients (15 males and 5 females, aged 38.76 years, 30 intervertebral spaces) were treated with the Solis cage fusion, and the preoperative JOAscores were 9-16, averaged 11.4; in Group B, 21 patients (15 males and 6 females,aged 37-78 years, 23 intervertebral spaces) were treated with the titanium cagefusion, and the preoperative JOA scores were 8-13, averaged 10.1; in Group C, 23 patients (18 males and 5 females, aged 32-76 years, 28 intervertebral spaces)were treated with the autogenous iliac crest graft combined with the titanium plate fixation, and the preoperative JOA scores were 9-14, averaged 10.6. The comparative analysis was made among the 3 groups in the following aspects: X-ray exposure time, time working on the iliac bone, operation time, hemorrhage amount，complication incidence after operation, cervical vertebral fusion rate, symptom relief rate, and recovery rate of the JOA score. Results According to the follow-upfor 2-15 months averaged 12 months, the time working on the iliac bone was longer in Group C than in Groups A and B (11.5±2.4 vs 4.1±1.7 minand 4.2±1.9 min, P＜0.05); the operation time was longer in Group C than in Groups A and B (98.3±14.7 min vs 55.5±10.3 min and 56.8±12.6 min, P＜0.05); and the X-ray exposure time was longer in Group C than in Groups A and B (7.8±1.8 min vs 4.3±1.2 min and 4.2±1.3 min, P＜0.05). Also, the hemorrhage amount in Group C was much greater than in Groups A and B (145.8±19.3 ml vs 65.8±10.2 ml and 67.2±12.3 ml,P＜0.05). The postoperative complication rate was lower in Groups A and Bthan in Group C (P＜0.05). There was a significant difference in the complication rate in the cervical region between Group A (5.0%±1.8%) and Group B (14.3%±2.6%,Plt;0.05）. The fusion rate in Groups A and B was 100% 3-4 monthsafteroperation, and there was no difference when compared with that in Group C. The recovery rates of the JOA scores in the three groups were 81.9%±3.2%，78.9%±7.3%, and 76.3%±9.4%, respectively, and there was no significant difference among the three groups. Conclusion The Solis cage fusion has a better therapeutic effect in treating prolapse of the cervical intervertebral disc than the titanium cage fusion and the autogenous iliac crest graft combined with the titanium plate fixation. The Solis cage fusion also makes the operation easier, with a more rapid recovery rate and fewer postoperative complications in the patient.
Objective To investigate the clinical effect of free forearm flap and titanium mesh in repairing maxillary defects. Methods From January 2002 to November 2002,partial maxillectomy or maxillectomy wereperformed in 3 patients with maxillary gingival carcinoma, in 1 patient with palatine mucoepicermoid carcinoma and in 1 patient with maxillary sinus carcinoma. Maxillary defects were reconstructed withfree forearm flaps ranging from 4 cm×5 cm to 6 cm×7 cm and titanium mesh.The effect was estimated by clinical examination, CT and nasopharyngoscope. Results Five cases were followed up 515 months. All the flaps were alive. Facial, alveolar process and palatal contours were restored well. Epithelium was found on the nostril surface of the titanium mesh. The functions of speech and chew were restored well. Conclusion A combination of the free forearm flap and titanium mesh is an ideal method in reconstruction of maxillary defects.
ObjectiveTo study the effect of titanium particles on the proliferation, differentiation, and cytomorphology of osteoblasts, and to explore the possible internal relations and mechanism. MethodsCalvarial osteoblasts were separated from 10 newborn Sprague Dawley rats by repeated enzyme digestion, and were cultured in vitro. The cells were identified by alkaline phosphatase (ALP) staining and alizarin red staining. The cells at passage 3 were cultured with titanium particles culture medium at concentrations of 0.01, 0.05, 0.1, 0.5, and 1 mg/mL (0.01, 0.05, 0.1, 0.5, and 1 mg/mL groups). The absorbance (A) values were detected by cell counting kit 8 at 7 days after cultured to compare the effect of titanium particles at different concentrations on proliferation, and median lethal concentration was screened out. The expression of collagen type I was detected by ELISA to observe the effect of titanium particles on differentiation. The osteoblasts co-cultured with titanium particles of median lethal concentration (experimental group) for 7 days, and double fluorescence staining with FITC-phalloidine and propidium iodide was performed. The cytomorphology variation of osteoblasts after swallowing titanium particles was observed under laser scanning confocal microscope. The osteoblasts at passage 3 cultured with culture medium without titanium particles served as control group. ResultsThe cultured cells were identified as osteoblasts by ALP staining and alizarin red staining. Different concentrations of titanium particles could inhibit osteoblasts proliferation and differentiation in varying degrees, showing significant difference when compared with the control group at 7 days after culture (P<0.05). The cell proliferation and differentiation were decreased with increased titanium particles concentration; significant differences were found between the other groups (P<0.05) except 0.01 and 0.05 mg/mL groups (P>0.05). The median lethal concentration of titanium particles was 0.5 mg/mL. Laser scanning confocal microscope showed cellular shrinking, microfilaments distortion, pseudopodia contraction of osteoblasts that swallowed titanium particles in the experimental group. ConclusionTitanium particles can inhibit proliferation and differentiation of osteoblasts. The effect may be related to variation of cytomorphology after swallowing titanium particles.
Objective To evaluate the reliability and the advantageof canal laminoplasty with laminoplasty over laminectomy for treatment of lumbar spinal stenosis.Methods From June 2000 to September 2004, the titanium miniplate fixation technique was applied to re-implantation of the vertebral lamina in the lumbar spine. The vertebral lamina was made with a specially made osteotome and a special technique in 18 patients with lumbar spinal stenosis. Results The patients were followed up for 1 yr and 8 mon on average (range, 3 mon4 yr and 3 mon) and were observed to have a bony fusion of the re-implanted lamina 3-9 months postoperatively. There was no nonunion, displacement of the re-implanted lamina, overgrowth of the anterior bone edge of osteotomy, recompression of the nerves or instability of the lumbar spine. Conclusion The result demonstrates that canal laminoplasty with the titanium miniplate re-implantation of the vertebral lamina in lumbar spine can restore the normal anatomy, keep stability of the spine, and avoid adhesion and scar in the canal.
In recent years, bone implant materials such as titanium and titanium alloys have been widely used in the biomedical field due to their excellent mechanical properties and good biocompatibility. However, in clinical practice, bacterial adhesion to the material surface and postoperative infection issues may lead to implantation failure. Based on the antibacterial mechanism, this review elaborated on the antibacterial surface design of titanium implants from the aspects of anti-bacterial adhesion, contact sterilization and photocontrol sterilization. Surface modification of titanium or titanium-based alloy implants with different techniques can inhibit bacteria and promote osseointegration. Thus, the application range of multifunctional titanium-based implants in the field of orthopedics will be expanded.
This paper aims to explore the effect of electrical stimulation of triboelectric nanogenerators (TENGs) on the osteogenic and other biological behaviors of mouse embryonic osteoblast precursor cells (MC3T3-E1 cells) on titanium surfaces. First, an origami-type TENG was fabricated, and its electrical output performance was tested. The optimal current of the generator and the feasibility of the experiment were verified by the CCK-8 assay and scratch assay. At the optimal current, the osteogenic conditions of the cells in each group were determined by quantitative analysis of the total protein content, alkaline phosphatase (ALP) activity, and alizarin red staining (ARS) on the titanium surface. Finally, the adhesion and spreading of cells on the titanium surface after electrical stimulation were observed. The results showed that the TENG had good electrical output performance, with an open-circuit voltage of 65 V and a short-circuit current of 42 μA. Compared with the rest of the current, a current strength of 30 μA significantly improved cell proliferation and migration, osteogenesis, and adhesion and spreading capabilities. The above results confirm the safety and operability of TENG in biomedical applications, laying the foundation for future TENG applications in reducing the time of bone integration around titanium implants after surgery.
ObjectiveTo review antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants, so as to provide reference for subsequent research. MethodsThe related research literature on antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants in recent years was reviewed, and the research progress was summarized based on different kinds of antibacterial substances and osteogenic active substances. ResultsAt present, the antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants includes: ① Combined coating strategy of antibiotics and osteogenic active substances. It is characterized in that antibiotics can be directly released around titanium-based implants, which can improve the bioavailability of drugs and reduce systemic toxicity. ② Combined coating strategy of antimicrobial peptides and osteogenic active substances. The antibacterial peptides have a wide antibacterial spectrum, and bacteria are not easy to produce drug resistance to them. ③ Combined coating strategy of inorganic antibacterial agent and osteogenic active substances. Metal ions or metal nanoparticles antibacterial agents have broad-spectrum antibacterial properties and various antibacterial mechanisms, but their high-dose application usually has cytotoxicity, so they are often combined with substances that osteogenic activity to reduce or eliminate cytotoxicity. In addition, inorganic coatings such as silicon nitride, calcium silicate, and graphene also have good antibacterial and osteogenic properties. ④ Combined coating strategy of metal organic frameworks/osteogenic active substances. The high specific surface area and porosity of metal organic frameworks can effectively package and transport antibacterial substances and bioactive molecules. ⑤ Combined coating strategy of organic substances/osteogenic active substancecs. Quaternary ammonium compounds, polyethylene glycol, N-haloamine, and other organic compounds have good antibacterial properties, and are often combined with hydroxyapatite and other substances that osteogenic activity. ConclusionThe factors that affect the antibacterial and osteogenesis properties of titanium-based implants mainly include the structure and types of antibacterial substances, the structure and types of osteogenesis substances, and the coating process. At present, there is a lack of clinical verification of various strategies for antibacterial/osteogenesis dual-functional surface modification of titanium-based implants. The optimal combination, ratio, dose-effect mechanism, and corresponding coating preparation process of antibacterial substances and bone-active substances are needed to be constantly studied and improved.
Objective To investigate the effect and safety of the anterior uncovertebral joint resection in treatment of cervical spondylotic myelopathy accompanied by radiculopathy. Methods From March 2002 toJuly 2004, 9 patients (5 males, 4 females; aged 38-66) with cervical spondylotic myelopathy accompanied by radiculopathy underwent the anterior uncovertebral joint resection and discectomy using the titanium cage implantation. There were 6 unilateral and 3 bilateral compressed nerve roots. Results During the follow-up for 3-16 months, CT scanning or X-ray films revealed thatall the patients improved with an enlargement of the intervertebral foramen, and MRI demonstrated that compression of the spinal cord and nerve roots vanished.Seven patients had a relief in the radicular pain although the other 2 still had a residual pain. All the patients improved to some extent in symptoms of myelopathy. No patient suffered vertebral artery injury during the operation. Conclusion The uncovertebral joint resection can directly decompressthe nerve roots. The key to avoidance of an injury to the vertebral artery is agood understanding of the regional anatomy and a good performance of the operation.
ObjectiveTo investigate the effects of micro/nano-structure and antimicrobial peptides (AMPs) on antibacterial properties of titanium (Ti) metallic surface.MethodsTi disks were treated via sandblasted large-grit acid-etched (SLA) and alkali-heat treatment (AHT) to build the micro/nano-structure, on which AMPs were spin-coated with a certain amount (10, 30, 50, 70, and 90 μg). Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) were used to observe the surface structure and characterize the surface elements (i.e. contents of C, N, O, and Ti). Ti disks loaded with AMPs of difference amounts were co-cultured with Staphylococcus aureus (S. aureus) for 24 hours. After that, the formation and dimension of antibacterial circle were measured. Furthermore, the Ti disks treated with different approaches (untreated, SLA treatment, SLA+THA treatment, and 90 μg AMPs-loaded samples) were co-cultured with S. aureus and Escherichia coli (E.coli) for 3 hours, bacterial adhesion on the disks were evaluated by using SEM. The antibacterial performances in solution were quantitatively evaluated by immersing the Ti disks in bacterial solutions and measuring the absorbance (A) values.ResultsIt was found that the nanoporous structure could be easily constructed by SLA+AHT approach. After spin-coating AMPs, the nanopores with the diameter less than 200 nm were almost covered. According to the element analysis, with the increase of AMPs, the C content gradually increased; the N content was not detected until AMPs amount reached 70 μg on the disks. The diameter of antibacterial circle clearly depended on the AMPs amount. The Ti disks loaded with 90 μg AMPs had significantly larger antibacterial circles than the other Ti disks (P<0.05). Based on the SEM observation, the Ti disks loaded with 90 μg AMPs has the least bacterial attachment compared with the other Ti disks (P<0.05). TheA value of bacterial solution immersed with the Ti disks loaded with 90 μg AMPs was much lower than the other Ti disks (P<0.05).ConclusionThe approach of micro/nano-structure and AMPs can improve the antibacterial properties of Ti metallic surface.