Anti-tumour activity of Mg-6%Ag and Mg-10%Gd alloys in mice with inoculated melanoma

Overview of biodegradable materials for bone repair and osteosarcoma treatment: From bulk to scaffolds

Osteosarcoma, the most common type of malignant bone tumor that affects growing bones in teenagers and children, has become a significant challenge for medical science. The combination of chemotherapy and surgery has been the standard treatment strategy for decades. However, concerns about tumor recurrence and the toxic effects of the drugs continue to drive materials scientists to develop multifunctional scaffolds that can simultaneously support bone regeneration and prevent tumor recurrence. Emergent multifunctional scaffolds have the potential to foster essential and dynamic cellular communication, which can directly target, signal, stimulate, and enhance the body's natural bone repair response. This review emphasizes the mechanisms involved and highlights various technologies and manufacturing processes that align with the capability of these scaffolds to effectively promote bone repair, especially in the presence of osteosarcoma. Additionally, the review summarizes the current state of knowledge regarding scaffolds based on magnesium (Mg), zinc (Zn), and iron (Fe), as well as the antitumor properties of their corrosion products. The review also discusses the therapeutic potential of Mg-, Zn-, and Fe-based materials in inhibiting osteosarcoma cell proliferation. The article elaborates on the main research challenges and prospects of biodegradable materials for bone repair and osteosarcoma treatment.

The Recent Developments of Thermomechanical Processing for Biomedical Mg Alloys and Their Clinical Applications

Magnesium (Mg) alloys have gained much attention for biomedical applications, due to their attractive properties, such as high specific strength, low density, low elasticity modulus, high damping capacity, biodegradation, and relatively good cytocompatibility. However, the biomedical use of Mg alloys also faces several challenges, primarily due to their low corrosion resistance and insufficient strength. Therefore, improving the strength and corrosion resistance of biomedical Mg alloys has become a critical issue. This review briefly summarizes the selection of appropriate alloying elements for biomedical Mg alloys, which is the fundamental factor in determining their microstructure, cytocompatibility, mechanical properties, and corrosion performance. It also discusses typical thermomechanical processing methods, including hot extrusion, hot rolling and hot forging, and examines the influence of deformation mode on microstructure, mechanical properties, and degradation behavior. Specifically, combining different thermomechanical processing methods could be an optimal choice, as it leverages the high efficiency and effectiveness of each method. Finally, the clinical application of biomedical Mg alloys in various fields are summarized and discussed to highlight their potential prospect and corresponding challenges. This review aims to provide insights for the rationale design and development of high-performance biomedical Mg alloys for widespread clinical applications.

Biodegradable Mg-1%Ca alloy inhibits the growth of cervical cancer

The traditional treatment for cervical cancer involves aggressive surgery combined with radiotherapy and chemotherapy. Nevertheless, these treatments have certain limitations and side effects, thus breakthroughs and advances are required in cervical cancer therapy. Magnesium alloy is a promising antitumor biomaterial with excellent biocompatibility and biodegradability. However, the potential effects of magnesium alloy on cervical tumors have not been extensively explored. Recent studies have demonstrated that adding a small amount of calcium to the magnesium matrix can reduce grain size and corrosion rate while providing good biocompatibility. We conductedin vivoandin vitroexperiments to test the antitumor properties of Mg-1%Ca alloys. The results indicated that the Mg-1%Ca alloy released Mg2+and OH-more slowly, inhibited the proliferation of SiHa and HeLa cells, induced apoptosis in tumor cells, disrupted the cytoskeleton, and inhibited cell migration and invasion. At the molecular level, Mg-1%Ca alloy significantly activated the mitochondrial apoptosis pathway and inhibited the MAPK/ERK signaling pathway. In the future, Mg-1%Ca may be employed in the treatment of cervical cancer as a novel adjuvant therapeutic material with anticancer function to prevent the occurrence and progression of cancer proliferation and metastasis.

Hydrogen-Generating Magnesium Alloy Seed Strand Sensitizes Solid Tumors to Iodine-125 Brachytherapy

Radioactive iodine-125 (125I) seed implantation, a brachytherapy technique, effectively kills tumor cells via X-rays and gamma rays, serving as an alternative therapeutic option following the failure of frontline treatments for various solid tumors. However, tumor radioresistance limits its efficacy. Hydrogen gas has anticancer properties and can enhance the efficacy of immunotherapy. However, its role in radiotherapy sensitization has rarely been reported. Many current hydrogen delivery methods involve hydrogen-generating nanomaterials, such as magnesium-based nanomaterials. This study introduces an AZ31 magnesium alloy 125I seed strand (termed AMASS) with pH-dependent slow-release hydrogen characteristics and excellent mechanical properties. AMASS can be implanted into tumors via minimally invasive surgery, releasing hydrogen around the 125I seeds. In vitro experiments showed that hydrogen from AMASS degradation significantly inhibited tumor proliferation, increased apoptosis, disrupted redox homeostasis and mitochondrial membrane potential, reduced adenosine triphosphate levels, and induced DNA damage due to 125I radiation. In mouse xenograft and rabbit liver tumor models, hydrogen from AMASS showed superior therapeutic effects compared with 125I seeds alone, with no noticeable side effects. In addition, AMASS has a uniform radiation dose distribution and simple implantation. Therefore, hydrogen from AMASS enhanced 125I seed efficacy, supporting the further promotion and application of 125I seed implantation in cancer therapy.

Mg alloys with antitumor and anticorrosion properties for orthopedic oncology: A review from mechanisms to application strategies

As a primary malignant bone cancer, osteosarcoma (OS) poses a great threat to human health and is still a huge challenge for clinicians. At present, surgical resection is the main treatment strategy for OS. However, surgical intervention will result in a large bone defect, and some tumor cells remaining around the excised bone tissue often lead to the recurrence and metastasis of OS. Biomedical Mg-based materials have been widely employed as orthopedic implants in bone defect reconstruction, and, especially, they can eradicate the residual OS cells due to the antitumor activities of their degradation products. Nevertheless, the fast corrosion rate of Mg alloys has greatly limited their application scope in the biomedical field, and the improvement of the corrosion resistance will impair the antitumor effects, which mainly arise from their rapid corrosion. Hence, it is vital to balance the corrosion resistance and the antitumor activities of Mg alloys. The presented review systematically discussed the potential antitumor mechanisms of three corrosion products of Mg alloys. Moreover, several strategies to simultaneously enhance the anticorrosion properties and antitumor effects of Mg alloys were also proposed.

Evaluation of the biocompatibility, antibacterial and anticancer effects of a novel nano-structured Fe-Mn-based biodegradable alloys in-vitro study

Scientific backgrounds

Development of nanostructured biodegradable alloys has generated a great deal of interest in the recent years as they offer promising bioactive materials for reconstruction of bony defects following traumatic fractures or surgical excision of tumors.

Objectives

The aim of the current study was to investigate the biocompatibility of Iron-Manganese -based alloys (Fe-Mn) with addition of copper (Cu), Tungsten (W) and cobalt (Co) to obtain 3 different alloys namely, Fe-Mn-Cu, Fe-Mn-W, and Fe-Mn-Co on normal oral epithelial cell line,and their possible anticancer effect on MG-63: osteosarcoma cell line.

Materials and methods

The sulforhodamine B (SRB) assay was used to assess cell viability percentage of both cell lines after exposure to discs of the proposed experimental alloys. Moreover, the antibacterial effect of such alloys against Escherichia coli (E. coli) was tested using disc diffusion susceptibility (Kirby-Bauer method) and colony suspension method.

Results

The cell viability percentage of oral epithelial cell line showed a significant increase in all the experimental groups in comparison to the control group. The highest percentage was observed in Fe-Mn-Co group, followed by Fe-Mn-W then Fe-Mn-Cu, at 24 and 72-h intervals, respectively. While the cell viability percentage of osteosarcoma cell line showed significant increase in all the experimental groups at 24-h intervals, it showed a significant drop in all the study groups at 72-h intervals. The lowest percentage was observed in Fe-Mn-Cu group, followed by Fe-Mn-W then Fe-Mn-Co. Moreover, all the examined study groups didn't show any inhibition zones against E. coli reference culture.

Conclusions

The novel nanostructured biodegradable Fe-Mn-Cu, Fe-Mn-W, and Fe-Mn-Co metal alloys exhibit good biocompatibility on oral epithelial cell lines with the enhancement of cell proliferation in a time-dependent manner that favors bone regeneration. On the other hand, all the alloys manifested possible anticancer activity against MG-63: osteosarcoma cell line. Furthermore, our study sheds the light on the importance of Co, W and Cu as promising alloying elements. However, the antibacterial activity of the examined alloys is still questionable.

Clinical relevance

The novel nanostructured biodegradable Fe-Mn-Cu, Fe-Mn-W, and Fe-Mn-Co metal alloys offer promising bioactive materials for reconstruction of bony defects following traumatic fractures or surgical excision of tumors, In addition, they could be excellent alternatives for undegradable or non-resorbable alloys that are commonly used. Moreover, they could be used as beneficial 3D printing materials to obtain patient-specific medical implants that favor bone regeneration in addition to manufacturing of plates and screws suitable for fracture fixation.