In Situ Growth of a Metal–Organic Framework on Graphene Oxide for the Chemo-Photothermal Therapy of Bacterial Infection in Bone Repair

Abstract

Bacterial infection with high morbidity (>30%) seriously affects the defect’s healing after bone transplantation. To this end, chemotherapy and photothermal therapy have been utilized for antibacterial treatment owing to their high selectivity and minimal toxicity. However, they also face several dilemmas. For example, bacterial biofilms prevented the penetration of antibacterial agents and local temperatures (over 70 °C) caused by the photothermal therapy damaged normal tissue. Herein, a co-dispersion nanosystem with chemo-photothermal function was constructed via the in situ growth of zeolitic imidazolate framework-8 (ZIF-8) on graphene oxide (GO) nanosheets. In this nanosystem, GO generates a local temperature (∼50 °C) to increase the permeability of a bacterial biofilm under near-infrared laser irradiation. Then, Zn ions released by ZIF-8 seized this chance to react with the bacterial membrane and inactivate it, thus realizing efficient sterilization in a low-temperature environment. This antibacterial system was incorporated into a poly-l-lactic acid scaffold for bone repair. Results showed that the scaffold showed a high antibacterial rate of 85% against both Escherichia coli and Staphylococcus aureus. In vitro cell tests showed that the scaffold promoted cell proliferation.

Closed-Loop Recycling of Carbon Fiber-Reinforced Composites Enabled by a Dual-Dynamic Cross-linked Epoxy Network

“…This result illustrated that these short and strong intermolecular HBs were more favorable to generate between imidazole and −OH. Through calculation, the interaction energy was approximately 24.4666 kcal/mol, which was consistent with that reported in the literature . This interaction was further proved by wavefunction analysis (Figure e,f).…”

“…Through calculation, the interaction energy was approximately 24.4666 kcal/mol, which was consistent with that reported in the literature. 41 This interaction was further proved by wavefunction analysis (Figure 3e,f). As a new visual method, the independent gradient model based on Hirshfeld partition (IGMH) analyses can colorfully visualize the position and intensity of intermolecular and intramolecular interactions.…”

Construction of magnetic nanochains to achieve magnetic energy coupling in scaffold

“…4 a. The pore size of the scaffold was 800 ± 50 μm, which was proven to be beneficial to cell adhesion and climbing growth [ 31 , 32 ]. The phase composition of the scaffolds was assessed using XRD (Fig.…”

Highly Dispersed Cu Produced by Mechanical Stress-Activated Redox Reaction to Establish Galvanic Corrosion in Fe Implant

“…The bactericidal behavior was conducted by the plate counting method using Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) bacterial strains, since they were common bacteria associated with implantrelated infections. 24,25 The bacterial strains were incubated in a lysogeny broth (LB) medium at 37 °C for 12 h in a shaker incubator. The obtained bacteria suspension was shaken for 10 min to achieve complete mixing and then diluted with LB media 10 4 times.…”