MedMat

MOFs with enhanced photothermal and photocatalytic effects for rapid sterilization

Yue Luo, Xiangmei Liu — Mon, 16 May 2022 00:00:00 +0800

Background: Antibiotics commonly used to treat bacterial infections in clinical practice can lead to the creation of drug-resistant bacteria, which are more difficult to eradicate. Therefore, there is an urgent need to develop a new antibacterial agent and antibacterial means that will not make bacteria resistant to resistance.

Methods: We synthesized MoO42-/PCN-222 composites using a simple hydrothermal and electrostatic adsorption methods. We characterized the successful synthesis of the material by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). Then we tested the photocatalytic and photothermal properties of the materials, and finally we evaluated the antibacterial properties of the materials against Staphylococcus aureus by the spread plate method.

Results: The results showed that MoO42+/PCN-222 composite had excellent antibacterial properties, and 20MoO42+/PCN-222 could kill 94.05% of Staphylococcus aureus under 660 nm light irradiation for 10 minutes.

Conclusions: In this article, we synthesized MoO42-/PCN-222 composites by a simple hydrothermal and electrostatic bonding method. The material has excellent photocatalytic and photothermal effects, so the composite material has excellent killing effect on S. aureus. We believe this work can provide new insights for the application of PCN-222 based materials.

Preparation of Doxorubicin-loaded Polylactic acid/graphene oxide nanofibrous membranes with different structures by electrospinning for cancer therapy

Mon, 16 May 2022 00:00:00 +0800

Background: Intravenous administration is still often used as adjuvant therapy after breast cancer resection, with toxic side effects. It is important to find a method of local administration to avoid the high cytotoxicity.

Methods: In the paper, a series of polylactic acid (PLA)-based nanofibers loaded with Doxorubicin (DOX) by blended and coaxial electrospinning were prepared to localize anticancer.

Results: Scanning electron microscope (SEM) shows that all nanofibers have smooth surfaces and uniform diameters, and DOX is uniformly dispersed in the fibers.

Conclusions: All electrospun fibers can effectively relieve the release of DOX and possess the ability to kill cells, and the ability of coaxial spinning is better than that of blended spinning.

ZnO nanorod arrays on Ti implant for self-antibacterial application

Jun Li, Xiangmei Liu — Mon, 16 May 2022 00:00:00 +0800

Background: Implant-related infection will inhibit implant-bone osteointegration, even resulting in an unavoidable second surgery in severe cases. Therefore, developing artificial implant materials with effective self-antibacterial ability by surface engineering is central to overcome implant-related infection.

Methods: Herein, the ZnO nanorod arrays were prepared on Ti implant by atomic layer deposition and hydrothermal growth method.

Results: The obtained ZnO nanorod arrays grow preferentially along the near-perpendicular direction, displaying hexagonal prisms with an average diameter of about80 nm. Notably, the ZnO nanorod arrays show the high antibacterial rate of 99.39% ± 0.27% against S. aureus. The possible antibacterial mechanisms of ZnO nanorods are discussed.

Conclusions: In summary, the self-antibacterial ZnO nanorod arrays on Ti implant have great potential in implant-related infection application. This work provided the insight into the self-antibacterial therapy of Ti implant by surface engineering.

TiB particle-stimulated nucleation of recrystallization behavior in a novel Ti-Mo-Fe biomedical titanium alloy

Hanzhao Qin, Li Ma, Chenglin Li — Mon, 16 May 2022 00:00:00 +0800

Background: Beta titanium alloys are widely used in biomedical implants because of their high strength and low modulus, for example, Ti-Mo-Fe based alloys exhibit superior mechanical properties and are good condidates for bone implants. A novel biomedical Ti-9.2Mo-2Fe-0.1B (wt.%) beta titanium alloy was developed for biomedical purpose. Therefore, in this study, we investigated the microstrucural evolution of the novel alloy in the early stage of annealing to understand its static recrystallization behavior.

Methods: The alloy samples were cold compressed and then subjected to a beta solution treatment for a short time. The microstructural and textural evolution at the early-stage of static recrystallization were investigated by using electron backscatter diffraction (EBSD) technique.

Results: EBSD observations reveal that new grains/subgrians are nucleated in particles deformation zones that were the beta matrix and twins surrounded with TiB particles. High angle grain boundaries were formed between the recystallized grains and subgrains via various lattice rotation. The recrystallized microstructures exhibited weakened textures in the beta solution-treated Ti-9.2Mo-2Fe-0.1B alloy.

Conclusions: The PSN mechanism is the main recrystallization mechanism in the early stage of static recrystallization. Multiple grains/subgrains are nucleated in the matrix and twins in the vicinty of TiB particles by the lattice rotation. The random rotation leads to formation of large angle grain boundaries and weaken recystallization textures.

Preface of MedMat

Yanglong Hou — Mon, 16 May 2022 00:00:00 +0800