Synergistic Effect of Magneto-Mechanical Bioengineered Stem Cells and Magnetic Field to Alleviate Osteoporosis

NIR-Responsive ZIF-8 Metal-Organic Framework Nanohybrids with Photothermal, Antimicrobial, and Osteoinductive Properties to Prevent Implant Infection

Current treatments for bone injuries face notable limitations such as adverse reactions to implant materials and increased risks of infection. There is an essential need for a therapeutic that will address these issues and decrease recovery times. Herein, a multifunctional nanohybrid zinc-based metal-organic framework integrated with gold nanoparticles (Au@ZIF-8) is synthesized to promote antibacterial and osteogenic benefits. Au@ZIF-8 is capable of converting light energy into heat and has demonstrated its ability to increase the surrounding temperature by ≈30 °C. As a result, Au@ZIF-8 has exhibited bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) upon exposure to near-infrared (NIR) irradiation. Concurrently, Au@ZIF-8 sustains the release of zinc ions from the nanohybrid for the potential of bone repair. When combined with a gelatin-based hydrogel, Au@ZIF-8 significantly elevated osteogenic gene expression and promoted preosteoclast differentiation through the sustained zinc ion release, as opposed to a gel-only control. The potential of the multifunctional nanohybrid is further demonstrated as a coating material for titanium orthopedic implants to introduce antibacterial properties and promote osteogenic differentiation of preosteoblasts for bone healing. Given its excellent antibacterial in response to NIR irradiation and osteogenic abilities, Au@ZIF-8 is a promising photothermal therapy for bone injuries.

Electro- and Magneto-Active Biomaterials for Diabetic Tissue Repair: Advantages and Applications

The diabetic tissue repair process is frequently hindered by persistent inflammation, infection risks, and a compromised tissue microenvironment, which lead to delayed wound healing and significantly impact the quality of life for diabetic patients. Electromagnetic biomaterials offer a promising solution by enabling the intelligent detection of diabetic wounds through electric and magnetic effects, while simultaneously improving the pathological microenvironment by reducing oxidative stress, modulating immune responses, and exhibiting antibacterial action. Additionally, these materials inherently promote tissue regeneration by regulating cellular behavior and facilitating vascular and neural repair. Compared to traditional biomaterials, electromagnetic biomaterials provide advantages such as noninvasiveness, deep tissue penetration, intelligent responsiveness, and multi-stimuli synergy, demonstrating significant potential to overcome the challenges of diabetic tissue repair. This review comprehensively examines the superiority of electromagnetic biomaterials in diabetic tissue repair, elucidates the underlying biological mechanisms, and discusses specific design strategies and applications tailored to the pathological characteristics of diabetic wounds, with a focus on skin wound healing and bone defect repair. By addressing current limitations and pursuing multi-faceted strategies, electromagnetic biomaterials hold significant potential to improve clinical outcomes and enhance the quality of life for diabetic patients.

An Integrated Microcurrent Delivery System Facilitates Human Parathyroid Hormone Delivery for Enhancing Osteoanabolic Effect

Human parathyroid hormone (1-34) (PTH) exhibits osteoanabolic and osteocatabolic effects, with shorter plasma exposure times favoring bone formation. Subcutaneous injection (SCI) is the conventional delivery route for PTH but faces low delivery efficiency due to limited passive diffusion and the obstruction of the vascular endothelial barrier, leading to prolonged drug exposure times and reduced osteoanabolic effects. In this work, a microcurrent delivery system (MDS) based on multimicrochannel microneedle arrays (MMAs) is proposed, achieving high efficiency and safety for PTH transdermal delivery. The internal microchannels of the MMAs are fabricated using high-precision 3D printing technology, providing a concentrated and safe electric field that not only accelerates the movement of PTH but also reversibly increases vascular endothelial permeability by regulating the actin cytoskeleton and interendothelial junctions through Ca2+-dependent cAMP signaling, ultimately promoting PTH absorption and shortening exposure times. The MDS enhances the osteoanabolic effect of PTH in an osteoporosis model by inhibiting osteoclast differentiation on the bone surface compared to SCI. Moreover, histopathological analysis of the skin and organs demonstrated the good safety of PTH delivered by MDS in vivo. In addition to PTH, the MDS shows broad prospects for the high-efficiency transdermal delivery of macromolecular drugs.

Mechano-Responsive Biomaterials for Bone Organoid Construction

Mechanical force is essential for bone development, bone homeostasis, and bone fracture healing. In the past few decades, various biomaterials have been developed to provide mechanical signals that mimic the natural bone microenvironment, thereby promoting bone regeneration. Bone organoids, emerging as a novel research approach, are 3D micro-bone tissues that possess the ability to self-renew and self-organize, exhibiting biomimetic spatial characteristics. Incorporating mechano-responsive biomaterials in the construction of bone organoids presents a promising avenue for simulating the mechanical bone microenvironment. Therefore, this review commences by elucidating the impact of mechanical force on bone health, encompassing both cellular interactions and alterations in bone structure. Furthermore, the most recent applications of mechano-responsive biomaterials within the realm of bone tissue engineering are highlighted. Three different types of mechano-responsive biomaterials are introduced with a focus on their responsive mechanisms, construction strategies, and efficacy in facilitating bone regeneration. Based on a comprehensive overview, the prospective utilization and future challenges of mechano-responsive biomaterials in the construction of bone organoids are discussed. As bone organoid technology advances, these biomaterials are poised to become powerful tools in bone regeneration.

Radiofrequency Electromagnetic and Pulsed Magnetic Fields Protected the Kidney Against Lipopolysaccharide-Induced Acute Systemic Inflammation, Oxidative Stress, and Apoptosis by Regulating the IL-6/HIF1α/eNOS and Bcl2/Bax/Cas-9 Pathways

Background/Objectives: Sepsis-associated acute kidney injury caused by lipopolysaccharide (LPS) is related to hypoxia, amplification of the inflammatory response, oxidative stress, mitochondrial dysfunction, and apoptosis. This study aims to explore the protective effects of a radiofrequency electromagnetic field (RF-EMF) and a pulsed magnetic field (PMF) on acute kidney injury in rats. Materials and methods: Forty female Wistar albino rats were randomly divided into five groups (each containing eight rats): control, LPS, RF-EMF, PMF, and RF-EMF + PMF groups. Six hours after LPS application, blood and tissues were removed for histopathological, immunohistochemical, biochemical, and genetic analysis. Results: Histopathological findings, caspase-3, inducible nitric oxide synthase and tumor necrosis factor-alpha immunoexpressions, total oxidant status and oxidative stress index levels, and interleukin-6, hypoxia-inducible factor alpha, Bcl-2-associated X protein, and caspase 9 gene expression in kidney tissue and blood urine nitrogen and creatinine levels in blood were increased, whereas endothelial nitric oxide synthase and B-cell lymphoma 2 gene expression were decreased in the LPS groups. Both RF-EMF and PMF reversed all these findings and recovered renal tissues. Conclusions: Noninvasive, nontoxic, low-cost PMF and RF-EMF, both single and combined, have been demonstrated to have renoprotective anti-inflammatory, antioxidant, and antiapoptotic effects.

Magnetic Hydroxyapatite Nanoparticles in Regenerative Medicine and Nanomedicine

This review focuses on the latest advancements in magnetic hydroxyapatite (mHA) nanoparticles and their potential applications in nanomedicine and regenerative medicine. mHA nanoparticles have gained significant interest over the last few years for their great potential, offering advanced multi-therapeutic strategies because of their biocompatibility, bioactivity, and unique physicochemical features, enabling on-demand activation and control. The most relevant synthetic methods to obtain magnetic apatite-based materials, either in the form of iron-doped HA nanoparticles showing intrinsic magnetic properties or composite/hybrid compounds between HA and superparamagnetic metal oxide nanoparticles, are described as highlighting structure-property correlations. Following this, this review discusses the application of various magnetic hydroxyapatite nanomaterials in bone regeneration and nanomedicine. Finally, novel perspectives are investigated with respect to the ability of mHA nanoparticles to improve nanocarriers with homogeneous structures to promote multifunctional biological applications, such as cell stimulation and instruction, antimicrobial activity, and drug release with on-demand triggering.