Titanium granules pre-treated with hydrogen peroxide inhibit growth of bacteria associated with post-operative infections in spine surgery

Preparation of a novel antibacterial magnesium carbonate coating on a titanium surface and its in vitro biocompatibility

Magnesium-based coatings have attracted great attention in surface modification of titanium implants due to their superior angiogenic and osteogenic properties. However, their biological effects as a carbonate-based constituent remain unrevealed. In this study, magnesium carbonate coatings were prepared on titanium surfaces under hydrothermal conditions and subsequently treated with hydrogen peroxide. Also, their antibacterial activity and in vitro cell biocompatibility were evaluated. The obtained coatings consisted of nanoparticles without cracks and exhibited excellent adhesion to the substrate. X-ray diffraction (XRD) results indicated pure magnesium carbonate coatings formed on the Ti surface after hydrothermal treatment. After hydrogen peroxide treatment, the phase composition of the coatings had no obvious change. Compared to the untreated coatings, the hydrogen peroxide-treated coatings showed increased surface roughness and hydrophilicity. Co-culture with Staphylococcus aureus (S. aureus) demonstrated that the obtained coatings had good antibacterial activity. In vitro cell culture results showed that the hydrogen peroxide-treated coatings enhanced the viability, proliferation, and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). These findings suggest that this MgCO3-based coating exhibits excellent antibacterial performance and osteogenic potential. Based on the above, this study provides a simple method for preparing titanium implants with dual antibacterial and osteogenic capabilities, holding great promise in clinical applications.

Design and 3D printing of novel titanium spine rods with lower flexural modulus and stiffness profile with optimised imaging compatibility

PURPOSE

To manufacture and test 3D printed novel design titanium spine rods with lower flexural modulus and stiffness compared to standard solid titanium rods for use in metastatic spine tumour surgery (MSTS) and osteoporosis.

METHODS

Novel design titanium spine rods were designed and 3D printed. Three-point bending test was performed to assess mechanical performance of rods, while a French bender was used to assess intraoperative rod contourability. Furthermore, 3D printed spine rods were tested for CT & MR imaging compatibility using phantom setup.

RESULTS

Different spine rod designs generated includes shell, voronoi, gyroid, diamond, weaire-phelan, kelvin, and star. Tests showed 3D printed rods had lower flexural modulus with reduction ranging from 2 to 25% versus standard rod. Shell rods exhibited highest reduction in flexural modulus of 25% (~ 77.4 GPa) and star rod exhibited lowest reduction in flexural modulus of 2% (100.8GPa). 3D printed rod showed reduction in stiffness ranging from 40 to 59%. Shell rod displayed highest reduction in stiffness of 59% (179.9 N/mm) and gyroid had least reduction in stiffness of 40% (~ 259.2 N/mm). Rod bending test showed that except gyroid, other rod designs demonstrated lesser bending difficulty versus standard rod. All 3D printed rods demonstrated improved CT/MR imaging compatibility with reduced artefacts versus standard rod.

CONCLUSION

By utilising novel design approach, we successfully generated a spine rod design portfolio with lower flexural modulus/stiffness profile and better CT/MR imaging compatibility for potential use in MSTS/other conditions such as osteoporosis. Thus, exploration of new rod designs in surgical application could enhance treatment outcome and improve quality of life for patients.

Exogenous Melatonin Enhances Rice Plant Resistance Against Xanthomonas oryzae pv. oryzae

Rice bacterial blight (BB), caused by Xanthomonas oryzae pv. oryzae, is one of the most serious diseases of rice. In this study we found that exogenous melatonin can increase rice resistance to BB. Treatment of rice plants with exogenous melatonin (20 µg/ml) increased nitrate reductase, nitric oxide synthase, and peroxidase activity, enabling high intracellular concentrations of melatonin, nitric oxide, and H₂O₂. The expression of NPR1, a key regulator in the salicylic acid signaling pathway, was upregulated more than 10-fold when the plants were challenged with melatonin. Similarly, the messenger RNA level of PDF1.2, a jasmonic acid-induced defense marker, was 15 times higher in the treated plants than in the control plants. Moreover, three pathogenesis-related proteins, PR1b, PR8a, and PR9, were upregulated 20-fold in the presence of melatonin. The application of melatonin (100 µg/ml) to soil-grown rice reduced the incidence of BB by 86.21%. Taken together, these results not only provide a better understanding of melatonin-mediated innate immunity to X. oryzae pv. oryzae in rice but also represent a promising cultivation strategy to protect rice against X. oryzae pv. oryzae infection.

[Effect of hydrogen peroxide on anti-infection and reducing postoperative drainage in multi-segmental lumbar surgery]

Objective

To investigate the effect of hydrogen peroxide on anti-infection and reducing postoperative drainage in multi-segmental lumbar surgery.

Methods

A clinical data of 510 patients with multi-segmental lumbar degenerative diseases who were treated with surgery between January 2017 and January 2018 was retrospectively analyzed. In study group, the incisions of 230 cases were washed with hydrogen peroxide before suture. In control group, the incisions of 280 cases were washed with normal saline before suture. There was no significant difference in gender, age, lesion type, disease duration, operative segment, and other clinical data between the two groups ( P>0.05). The operation time, intraoperative blood loss, postoperative drainage volume, and postoperative incidence of infection were recorded and compared between the two groups. The Centers for Disease Control and Prevention (CDC) standard was used to evaluate infection, which was divided into superficial infection and deep infection.

Results

All operations completed successfully. There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05). The postoperative drainage volume in the study group was significantly less than that in the control group ( t=-2.990, P=0.005). A total of 13 patients developed infection after operation, including 10 cases of superficial infection (2 cases in the study group and 8 cases in the control group) with the infection time of (7.3±1.5) days, and 3 cases of deep infection (all in the control group) with the infection time of (16.6±3.1) days. The incidences of superficial and deep infections in the study group were lower than those in the control group, but there was no significant difference between the two groups ( χ ²=2.595, P=0.123; P=0.256). All the superficial infections were Staphylococcus aureus infection and recovered after active dressing change. Among the patients with deep infections, 2 cases were infected by Staphylococcus aureus and 1 case was infected by Escherichia coli; and the incisions healed after being washed and sutured thoroughly, and active dressing change.

Conclusion

The incidence of postoperative infection and postoperative drainage volume can be reduced by washing the incision with hydrogen peroxide in multi-segmental lumbar surgery.

Oxygen Embolism and Pneumocephalus After Hydrogen Peroxide Application During Minimally Invasive Transforaminal Lumbar Interbody Fusion Surgery: A Case Report and Literature Review

BACKGROUND

Hydrogen peroxide (H₂O₂) solution is commonly used to irrigate wounds because of its hemostatic and antiseptic properties. Previous studies suggest that H₂O₂ can result in toxicity to keratinocytes and fibroblasts, but complications after H₂O₂ application, including oxygen embolism, which is one of the most severe, have rarely been reported.

CASE DESCRIPTION

A 40-year-old woman was diagnosed with L4-5 lumbar spinal stenosis and subsequently underwent minimally invasive transforaminal lumbar interbody fusion treatment at another hospital. Hypotension, hypoxia, and a decrease in end-tidal carbon dioxide pressure occurred immediately after H₂O₂ irrigation. After the operation, she was able to be extubated but remained comatose. Postoperative computed tomography scan revealed intracranial air trapping in the right frontal lobe and multiple cerebral infarction foci.

CONCLUSIONS

When using a knee-prone surgical position or in cases of dural laceration, the application of undiluted H₂O₂ solution should be avoided, especially in a surgical wound within a closed cavity. When hypotension, hypoxia, and a decrease in end-tidal carbon dioxide pressure occur immediately after H₂O₂ irrigation, oxygen embolism should be strongly suspected.