The development of magnesium-based biomaterials in bone tissue engineering: A review

Development of modified MgO/biochar composite for chemical adsorption enhancement to cleanup fluoride-contaminated groundwater

Fluoride contamination in groundwater has become a global environmental issue. Magnesium oxide (MgO) has demonstrated effectiveness as an adsorbent in treating fluoride pollution in groundwater. However, its use in powder and fine granular form often results in losses during the adsorption process, posing challenges for post-treatment recovery and potentially causing secondary environmental pollution. In this study, two novel fluoride adsorbents [rice husk (RH) and spent coffee grounds (SCG)-based magnesium oxide (MgO) biochar composites (MgO/RH and MgO/SCG)] were developed to cleanup fluoride-polluted groundwater. During the adsorbent synthesis process, RH and SCG biochar were pyrolyzed at 500 °C and modified by calcination using MgO. Both MgO/RH and MgO/SCG surfaces exhibited abundant pore structures and formed MgO crystal phases. Batch experiments results show that when the MgO/RH and MgO/SCG material dosages were 1 g/L, fluoride removal rates reached 80% and 86% respectively. The isotherms and kinetics of fluoride adsorption with MgO/RH and MgO/SCG followed the Langmuir isotherm equation and pseudo-second-order kinetic model. The maximum fluoride adsorption capacities of MgO/RH and MgO/SCG were 63.47 mg/g and 141.98 mg/g, respectively, indicating these materials used mono-layer adsorption mechanism for fluoride adsorption. The addition of MgO into the pores of porous adsorbent materials effectively increased their reactive sites and enhanced the adsorption performance of carbon materials. Particularly, SCG biochar had a richer pore structure than RH biochar, providing a larger contact surface area, facilitating the effective dispersion and doping of MgO into the pores. Therefore, MgO/SCG composite exhibited excellent fluoride adsorption properties in water, indicating the potential for developing a new type of MgO-modified SCG adsorbent material with green prospects. This composite effectively mitigated fluoride contamination, reducing the fluoride concentration in groundwater. Both RH and SCG are agricultural and food waste by-products, thus offering the opportunity to significantly reduce production, operation, and maintenance costs.

Mg-Sr-Ca containing bioactive glass nanoparticles hydrogel modified mineralized collagen scaffold for bone repair

The aim of this study is to explore the therapeutic effects of Mg-Sr-Ca containing bioactive glass nanoparticles sodium alginate hydrogel modified mineralized collagen scaffold (Mg-Sr-Ca-BGNs-SA-MC) on the repair of osteoporotic bone defect. During the study, Mg-Sr-Ca containing bioactive glass nanoparticles (Mg-Sr-Ca-BGNs) were synthesized using the sol-gel method, and the Mg-Sr-Ca-BGNs-SA-MC scaffold was synthesized by a simple method. The Mg-Sr-Ca-BGNs and the Mg-Sr-Ca-BGNs-SA-MC scaffold were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The elements of Mg, Sr, Ca and Si were effectively integrated into Mg-Sr-Ca-BGNs. SEM analysis revealed the presence of Mg-Sr-Ca-BGNs on the scaffold's surface. Furthermore, the cytotoxicity of the scaffolds were assessed using a live/dead assay. The result of the live/dead assay demonstrated that the scaffold materials were non-toxic to cell growth. More importantly, the in vivo study indicated that implanted scaffold promoted tissue regeneration and integration with newly formed bone. Overall, the Mg-Sr-Ca-BGNs-SA-MC scaffold is suitable for guided bone regeneration and beneficial to repair of osteoporotic bone defects.

Design of bone scaffolds with calcium phosphate and its derivatives by 3D printing: A review

Tissue engineering is a fascinating field that combines biology, engineering, and medicine to create artificial tissues and organs. It involves using living cells, biomaterials, and bioengineering techniques to develop functional tissues that can be used to replace or repair damaged or diseased organs in the human body. The process typically starts by obtaining cells from the patient or a donor. These cells are then cultured and grown in a laboratory under controlled conditions. Scaffold materials, such as biodegradable polymers or natural extracellular matrices, are used to provide support and structure for the growing cells. 3D bone scaffolds are a fascinating application within the field of tissue engineering. These scaffolds are designed to mimic the structure and properties of natural bone tissue and serve as a temporary framework for new bone growth. The main purpose of a 3D bone scaffold is to provide mechanical support to the surrounding cells and guide their growth in a specific direction. It acts as a template, encouraging the formation of new bone tissue by providing a framework for cells to attach, proliferate, and differentiate. These scaffolds are typically fabricated using biocompatible materials like ceramics, polymers, or a combination of both. The choice of material depends on factors such as strength, biodegradability, and the ability to facilitate cell adhesion and growth. Advanced techniques like 3D printing have revolutionized the fabrication process of these scaffolds. Using precise layer-by-layer deposition, it allows for the creation of complex, patient-specific geometries, mimicking the intricacies of natural bone structure. This article offers a brief overview of the latest developments in the research and development of 3D printing techniques for creating scaffolds used in bone tissue engineering.

Bioactive elements manipulate bone regeneration

While bone tissue is known for its inherent regenerative abilities, various pathological conditions and trauma can disrupt its meticulously regulated processes of bone formation and resorption. Bone tissue engineering aims to replicate the extracellular matrix of bone tissue as well as the sophisticated biochemical mechanisms crucial for effective regeneration. Traditionally, the field has relied on external agents like growth factors and pharmaceuticals to modulate these processes. Although efficacious in certain scenarios, this strategy is compromised by limitations such as safety issues and the transient nature of the compound release and half-life. Conversely, bioactive elements such as zinc (Zn), magnesium (Mg) and silicon (Si), have garnered increasing interest for their therapeutic benefits, superior stability, and reduced biotic risks. Moreover, these elements are often incorporated into biomaterials that function as multifaceted bioactive components, facilitating bone regeneration via release on-demand. By elucidating the mechanistic roles and therapeutic efficacy of the bioactive elements, this review aims to establish bioactive elements as a robust and clinically viable strategy for advanced bone regeneration.