Osteoporosis remission via an anti-inflammaging effect by icariin activated autophagy

Identification of chemical components and metabolites in rats after oral administration of Epimedium-Astragalus granule pair by liquid chromatography-high resolution mass spectrometry combined with diagnostic fragment ions and mass defect filtering

Herbal pairs are combinations of two relatively fixed herbs that are frequently used in clinical practice to achieve specific therapeutic effect. Epimedium and Astragalus are frequently used together in clinical settings. However, there is a lack of an in-depth understanding of the active components of these herbs in vivo. In this study, a method based on ultra-high-performance liquid chromatography coupled to high resolution mass spectrometry together with diagnostic fragment ions (DFIs) mass defect filtering (MDF) was developed to systematically screen and identify the chemical ingredients presenting in Epimedium-Astragalus granule pair (EAGP) and the absorbed components and their metabolites in rat plasma following oral administration. Using accurate mass determination, mass defect filtering and diagnostic fragment ion screening strategies, a total of eighty-five ingredients were identified in EAGP. By comparing the total ion chromatograms obtained from dosed rat plasma, blank rat plasma and EAGP solution, a total of forty-six compounds were detected in dosed rat plasma, including twenty-five prototypes and twenty-one metabolites. Among these, seventeen parent compounds were derived from Epimedium and eight were from Astragalus. These metabolites were associated with ononin (M1, M2, M9 M10 and M17), calycosin-7-O-β-D-glucoside (M6, M7, M8 and M13), icariin (M3, M4, M5, M11, M14, M15, M18, M19, M20 and M21) and methylnissolin (M12). The metabolic pathways included hydroxylation, demethylation, deglycosylation and glucuronidation. This study elucidated the potential pharmacologically active components of EAGP and provided essential data for the further study on its pharmacological materials basis and mechanism of action.

Icariin Supplementation Alleviates Cognitive Impairment Induced by d-Galactose via Modulation of the Gut-Brain Axis

Aging-related cognitive impairment seriously diminishes individuals' life quality. Icariin (ICA), a natural flavonoid separated from the herb Epimedium, is applied in the food industry to bolster immunity and cognitive function in Chinese culture, demonstrating considerable potential in alleviating aging-related cognitive impairment. However, the mechanisms by which ICA mitigates aging-related cognitive impairment have yet to be elucidated. In the study, an 8 week ICA administration strongly improved spatial learning and memory ability, reduced neural damage, and restored hippocampal mitochondrial ultrastructure in mice subjected to d-galactose (d-gal) induction. Mechanically, ICA alleviated colonic pathology and upregulated the expression of tight junction proteins. Moreover, ICA reshaped microbial composition, enriched short-chain fatty acid (SCFA)-producing genera, and upregulated microbiota-derived SCFA contents. Additionally, ICA enhanced cognitively related anti-inflammatory properties and antioxidant capacity. Intriguingly, SCFAs regulated by ICA mitigated mitochondrial dysfunction in vitro, namely, reversing inflammatory cytokine levels and antioxidant capacity, elevating ATP contents, and mitochondrial membrane potential. Furthermore, SCFAs regulated by ICA alleviated mitochondrial dysfunction by enhancing the oxidative phosphorylation pathway and upregulating mRNA expression of genes related to mitochondrial respiratory chain, thus improving cognitive function. The findings suggest that ICA alleviates d-gal-induced cognitive impairment via modulation of the gut-brain axis and mitochondrial function. The investigation underscores the potential therapeutic benefits of incorporating an ICA-enriched diet for cognitive enhancement.

Changing landscape of hematopoietic and mesenchymal cells and their interactions during aging and in age-related skeletal pathologies

Aging profoundly impacts mesenchymal and hematopoietic lineage cells, including their progenitors-the skeletal stem cells (SSCs) and hematopoietic stem cells (HSCs), respectively. SSCs are crucial for skeletal development, homeostasis, and regeneration, maintaining bone integrity by differentiating into osteoblasts, adipocytes, and other lineages that contribute to the bone marrow (BM) microenvironment. Meanwhile, HSCs sustain hematopoiesis and immune function. With aging, SSCs and HSCs undergo significant functional decline, partly driven by cellular senescence-a hallmark of aging characterized by irreversible growth arrest, secretion of pro-inflammatory factors (senescence associated secretory phenotype, SASP), and impaired regenerative potential. In SSCs, senescence skews lineage commitment toward adipogenesis at the expense of osteogenesis, contributing to increased bone marrow adiposity , reduced bone quality, and osteoporosis. Similarly, aged HSCs exhibit diminished self-renewal, biased differentiation, and heightened inflammation, compromising hematopoietic output and immune function. In this review, we examine the age-related cellular and molecular changes in SSCs and HSCs, their lineage decisions in the aging microenvironment, and the interplay between skeletal and hematopoietic compartments. We also discuss the role of senescence-driven alterations in BM homeostasis and how targeting cellular aging mechanisms may offer therapeutic strategies for mitigating age-related skeletal and hematopoietic decline.

Remodeling the Senescent Microenvironment for Promoting Osteoporotic Tendon-to-Bone Healing via Synergizing Senolytic Quercetin and Aligned Nanowire-Structured Hydrogels

Osteoporotic tendon-to-bone healing remains a major challenge, as cellular senescence disrupts tissue regeneration and impairs repair outcomes. Although the role of cellular senescence in rotator cuff repair is increasingly recognized, current strategies often overlook the complex pathological context, particularly the dual impacts of senescence on both bone marrow-derived mesenchymal stem cells (BMSCs) and tendon-derived stem cells (TDSCs). This gap hampers effective tendon-to-bone healing and integration, especially under osteoporotic conditions. Herein, a composite hydrogel system, quercetin-loaded aligned ultralong hydroxyapatite nanowire/gelatin-hyaluronic acid hydrogel (Que-AHNW/GH), has been developed to address these challenges. By integrating senolytic quercetin as a biological cue with highly aligned ultralong hydroxyapatite (HAP) nanowires as a topographical cue, the system remodels the senescent microenvironment, alleviating senescence in both BMSCs and TDSCs and promoting osteogenesis and tenogenesis. Que-AHNW/GH suppresses the PI3K/AKT pathway, enhances autophagy, and reduces senescence in both cell types. In vivo, Que-AHNW/GH improves bone tunnel regeneration, tendon repair, and tendon-to-bone integration in osteoporotic rats with rotator cuff injury. This system enhances biomechanical strength and gait performance and demonstrates excellent biosafety. These findings highlight the promising potential of Que-AHNW/GH as a multifunctional biomaterial for effectively promoting senescence-related tendon-to-bone healing, offering a promising solution for treating osteoporotic tendon-to-bone injuries.

Acid-responsive aggregated carrot-derived nanoantioxidants alleviate oxidative stress and restore osteoblast activity

BACKGROUND

Excessive generation of reactive oxygen species is a hallmark of the osteoporotic bone microenvironment, which leads to the damage of mitochondrial function and the deactivation of osteoblasts. Fruits and vegetables are rich sources of antioxidants, which play a key role in scavenging free radicals and maintaining the body's homeostasis.

RESULTS

Herein, we have developed a type of vesicle coming from carrots as nanoantioxidants to counteract oxidative stress and restore the vitality of osteoblasts for reversing osteoporosis. Nanovesicles are derived from carrot juice using a straightforward extrusion method, resulting in stable membrane structures containing various lipids and homologous active phytochemicals. Nanovesicles can maintain stable structures under normal physiological conditions (pH 7.4) and transform into aggregates in response to the acidic extracellular pH of osteoporosis (pH 4.0). As anticipated, nanovesicles can passively target and aggregate to osteoporotic bone, ease oxidative stress, restore mitochondrial function, promote osteoblastogenesis, and reduce bone loss in osteoporotic mice.

CONCLUSIONS

This work presents the first demonstration of nanovesicles derived from carrots as novel nanoantioxidants to realize the long-awaited osteogenesis, contributing to the exploration of a brand-new idea for reversing osteoporosis.

Directional Mushroom-Derived Scaffold for Microenvironment Regulation in Infected Bone Defects

Infected bone defects are a common clinical condition, but conventional treatments often fail to achieve the desired outcomes, including addressing antibiotic resistance and preventing nonunion complications. In the presented study, a functionalized decellularized mushroom stem scaffold is developed composed of its naturally aligned channels, Zn2+/curcumin MOFs, hydroxyapatite minerals, and icariin. In vitro, It is found that functionalized acellular mushroom stem scaffold can control bacterial infections through Zn2+/curcumin MOFs. The naturally aligned channels guide bone mesenchymal stem cells (BMSCs) migration, and the components adsorbed on the acellular substrate further promote the migration of BMSCs. Moreover, these functional components further accelerated the polarization of M2 macrophage and osteogenic differentiation of BMSCs. In vivo, the functionalized decellularized mushroom stem scaffold cleared infected bacteria within 3 days, induced extracellular matrix secretion and alignment, and promoted new bone formation to cover defects within 8 weeks. The functionalized decellularized mushroom stem scaffold provides a promising strategy for treating infectious bone defects.

Rejuvenation of Bone Marrow Mesenchymal Stem Cells: Mechanisms and Their Application in Senile Osteoporosis Treatment

Bone marrow mesenchymal stromal cells (BM-MSCs) are multipotent cells present in bone marrow; they play a crucial role in the process of bone formation. Cellular senescence is defined as a stable state of cell cycle arrest that impairs the functioning of cells. Research has shown that aging triggers a state of senescence in BM-MSCs, leading to a reduced capacity for osteogenic differentiation and the accumulation of senescent cells, which can accelerate the onset of various diseases. Therefore, it is essential to explore mechanisms and strategies for the rejuvenation of senescent BM-MSCs. Senile osteoporosis (SOP) is a metabolic bone disease characterized by reduced bone formation. The senescence of BM-MSCs is considered one of the most important factors in the occurrence and development of SOP. Therefore, the rejuvenation of BM-MSCs for the treatment of SOP represents a promising strategy. This work provides a summary of the functional alterations observed in senescent BM-MSCs and a systematic review of the mechanisms that facilitate the rejuvenation of senescent BM-MSCs. Additionally, we analyze the progress in and the limitations associated with the application of rejuvenated senescent BM-MSCs to treat SOP, with the aim of providing new insights for the prevention and treatment of SOP.

Biomimetic Extracellular Vesicles Containing Biominerals for Targeted Osteoporosis Therapy

Osteoporosis (OP) is a systemic skeletal disorder characterized by decreased bone mineral density and a heightened risk of fractures. Therapies for OP have primarily focused on balancing bone formation and bone resorption, but enhancing the remineralization of osteoporotic bone is also a key strategy for effective repair. Recent insights into biomineralization mechanisms have highlighted the essential role of mineral-containing extracellular vesicles (EVs) secreted by osteoblasts in promoting bone marrow mesenchymal stromal/stem cell (BMSC) differentiation and initiating matrix mineralization. Drawing from these principles, we developed a biomimetic approach to replicate the structure and function of the osteoblast-derived EVs by engineering biomimetic mitochondrial minerals with bone marrow homing cell membranes (CMs). This bone-targeted biomimetic system exhibits excellent biocompatibility, enhancing osteogenic differentiation and stimulating angiogenesis by regulating cellular energy metabolism. Additionally, the CM-coated structure shows affinity for collagen fibrils, effectively enhancing intrafibrillar collagen mineralization, thereby facilitating osteoporotic bone repair. Overall, the biomimetic system offers a safe and efficient therapeutic alternative, positioning it as a platform for bone tissue engineering and regenerative medicine.

Cellular senescence: A new perspective on the suppression of periodontitis (Review)

Cellular senescence, characterized by cell cycle arrest, can result in tissue dysfunction when senescent cells persist and accumulate. Periodontitis, a chronic inflammatory condition caused by the interaction between bacteria and the immune system of the host, primarily manifests as damage to periodontal tissues. Aging and inflammation are interlinked processes that exacerbate each other. The progression of localized chronic periodontal inflammation is often accelerated in conjunction with tissue and organ aging. The presence of senescent cells and release of inflammatory cytokines, immune modulators, growth factors and proteases that are associated with the senescence‑associated secretory phenotype contribute to the deterioration of periodontal tissues. The present review aimed to elucidate the mechanisms of cellular senescence and its potential impact on periodontitis, offering novel insights for modulating the inflammatory microenvironment of periodontal tissues.

Sequential delivery of IL-10 and icariin using nanoparticle/hydrogel hybrid system for prompting bone defect repair

The treatment of large bone defects remains challenging due to the lack of spatiotemporal management of the immune microenvironment, inflammation response and bone remodeling. To address these issues, we designed and developed a nanoparticle/hydrogel hybrid system that can achieve the combined and sequential delivery of an anti-inflammatory factor (IL-10) and osteogenic drug (icariin, ICA). A photopolymerizable composite hydrogel was prepared by combining gelatin methacryloyl (GelMA) and heparin-based acrylated hyaluronic acid (HA) hydrogels containing IL-10, and poly(dl-lactide-co-glycolide) (PLGA)-HA nanoparticles loaded with ICA were incorporated into the composite hydrogels. The nanoparticle/hydrogel hybrid system demonstrates an array of features including mechanical strength, injectability and photo-crosslinking. The rapid release of IL-10 from the hydrogel effectively exerts immunomodulatory activity, whereas the long-term sustained release of icariin from the PLGA-HA nanoparticles significantly triggers the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Notably, the combined delivery of IL-10 and ICA from the hybrid system exhibit a synergistic effect for bone remodeling in a critical cranial defect rat model. Our findings indicate the importance of the immunomodulatory microenvironment and osteogenic differentiation for high-quality skull remodeling, and thus the dual-factor releasing nanoparticle/hydrogel hybrid system could be a promising candidate for repairing bone defects.

Honeycomb Bionic Graphene Oxide Quantum Dot/Layered Double Hydroxide Composite Nanocoating Promotes Osteoporotic Bone Regeneration via Activating Mitophagy

Abnormal osteogenic and remodeling microenvironment due to osteoblast apoptosis are the primary causes of delayed fracture healing in osteoporotic patients. Magnesium (Mg) alloys exhibit biodegradability and appropriate elastic moduli for bone defects in osteoporosis, but the effect on the local bone remodeling disorder is still insufficient. Inspired by the "honeycomb," layered double hydroxide (LDH) with regular traps with graphene oxide quantum dots (GOQDs) inlayed is constructed by pulsed electrodeposition to generate GOQD/LDH composite nanocoatings on the surfaces of Mg alloy substrates. The honeycomb bionic multi-layer stereoscopic structure shows good regulation of the degradation of Mg alloy for the support of healing time required for osteoporotic bone defect. Within its lattice, the local microenvironment conducive to osteogenesis is provided by both the rescue effect of GOQD and LDH. The osteoblast apoptosis is rescued due to the activation of mitophagy to clear dysfunctional mitochondria, where the upregulation of BNIP3 phosphorylation played a key role. The osteoporotic rat model of femoral defects confirmed the improvement of bone regeneration and osseointegration of GOQD/LDH coating. In summary, honeycomb bionic composite nanocoatings with controllable degradation and excellent pro-osteogenic performance demonstrated a promising design strategy on Mg alloy implants in the therapy of osteoporotic bone defects.

Tailoring surface stiffness to modulate senescent macrophage immunomodulation: Implications for osteo-/angio-genesis in aged bone regeneration

The application of biomaterials in bone regeneration is a prevalent clinical practice. However, its efficacy in elderly patients remains suboptimal, necessitating further advancements. While biomaterial properties are known to orchestrate macrophage (MΦ) polarization and local immune responses, the role of biomaterial cues, specifically stiffness, in directing the senescent macrophage (S-MΦ) is still poorly understood. This study aimed to elucidate the role of substrate stiffness in modulating the immunomodulatory properties of S-MΦ and their role in osteo-immunomodulation. Our results demonstrated that employing collagen-coated polyacrylamide hydrogels with varying stiffness values (18, 76, and 295 kPa) as model materials, the high-stiffness hydrogel (295 kPa) steered S-MΦs towards a pro-inflammatory M1 phenotype, while hydrogels with lower stiffness (18 and 76 kPa) promoted an anti-inflammatory M2 phenotype. The immune microenvironment created by S-MΦs promoted the bioactivities of senescent endothelial cells (S-ECs) and senescent bone marrow mesenchymal stem cells BMSCs (S-BMSCs). Furthermore, the M2 S-MΦs, particularly incubated on the 76 kPa hydrogel matrices, significantly enhanced the ability of angiogenesis of S-ECs and osteogenic differentiation of S-BMSCs, which are crucial and interrelated processes in bone healing. This modulation aided in reducing the accumulation of reactive oxygen species in S-ECs and S-BMSCs, thereby significantly contributing to the repair and regeneration of aged bone tissue.

Zoledronic Acid Inhibits Lipopolysaccharide-Induced Osteoclastogenesis by Suppressing Macrophage NLRP3-Mediated Autophagy Pathway

INTRODUCTION

Inflammatory factors leading to bone loss significantly increase the risk of tooth loosening or implantation failure. Zoledronic acid (ZOL) is a widely used medication for effectively inhibiting excessive bone destruction, but its effect on alleviating inflammatory bone loss remains to be elucidated. In this study, we investigated whether ZOL alleviates inflammatory bone resorption through immunomodulatory effect.

METHODS

The viability of the cells was evaluated by Cell Counting Kit 8 (CCK8) assay. Osteoclast (OC) differentiation and function were determined by tartrate-resistant acid phosphatase (TRAP) staining and bone resorption pits assays, respectively. Autophagosomes and actin ring structures of OC were observed using transmission electron microscopy (TEM) and F-actin ring staining, respectively. The microstructure in mice maxillary alveolar bone model was observed by micro computed tomography (Miro-CT). Reverse transcription-quantitative PCR (RT-qPCR) to detect the mRNA expression of osteoclast-related genes and Western blot (WB) analysis to evaluate the protein expression levels of autophagy-related proteins and the NOD-like receptor family pyrin domain-containing protein 3 (NLRP3)-related proteins in pre-OCs.

RESULTS

The findings indicated that ZOL hindered lipopolysaccharide (LPS)-mediated OC differentiation, formation, bone resorption activity and autophagosome levels. Furthermore, ZOL diminished the expression of genes associated with OC. And the expression of proteins ATG7, LC3II, Beclin1, NLRP3-related proteins and tumor necrosis factor-α (TNF-α) protein were markedly decreased while P62 was increased, especially in the 1 μM ZOL group or MCC950 + ZOL group.

CONCLUSIONS

ZOL has a certain immunomodulatory effect that exhibits anti-inflammatory properties at lower concentrations, which can weaken LPS-induced OCs differentiation and function, and NLRP3-mediated autophagy pathway may participate in this process.

Icariin-Enhanced Osteoclast-Derived Exosomes Promote Repair of Infected Bone Defects by Regulating Osteoclast and Osteoblast Communication

Background

Infected bone defects pose a challenging clinical issue due to an imbalance of osteoclasts (OC) and osteoblasts (OB). Exosomes are crucial for intercellular signaling of OC and OB in bone repair. Icariin, has been shown to regulate the balance between OC and OB. However, the specific mechanisms by which icariin influences exosomes derived from osteoclasts, and subsequently impacts osteoblast activity, remain unclear. This study aims to investigate the effects of icariin-treated osteoclast-derived exosomes (ICA-OC-Exo) on osteoblast function and bone repair in cases of infected bone defects.

Methods

We investigated the exosome profile and localization of multivesicular bodies (MVB) and quantification of intraluminal vesicles (ILVs) in osteoclasts by using transmission electron microscopy. Additionally, the expressions of Rab27A and MITF, which are associated with exosome release, were determined through immunofluorescence staining and Western blot. The profiling of exosomal miRNA expression was conducted via miRNA-sequencing. The effects of ICA-OC-Exo on osteoblast differentiation were determined using RT-qPCR, Western blot, alkaline phosphatase staining. Additionally, ICA-OC-Exo was administered into the localized bone defect of the infected bone rat models, and bone formation was assessed using Micro-CT.

Results

Icariin increased the presence of MVBs in the cytoplasm through modulation of the MITF/Rab27A signaling pathway, resulting in higher number of ICA-OC-Exo compared to OC-Exo. Additionally, miR-331-3p expression in ICA-OC-Exo was found to be elevated compared to OC-Exo. ICA-OC-Exo was observed to stimulate osteoblast function by targeting FGF23, reducing DKK1, and subsequently upregulating ALP. In the in vivo study, ICA-OC-Exo exhibited the capacity to enhance bone healing at the site of a local bone defect following anti-infection treatment.

Conclusion

Icariin enhanced the quantification of OC-Exo and the expression of miRNA-331-3p in OC-Exo, leading to the regulation of osteoblast function via activation of the miRNA-331-3p/FGF23/DKK1 pathway. ICA-OC-Exo demonstrated potential clinical applicability in bone repair of infected bone defects.

Qiang Jin Mixture Promotes Osteogenic Differentiation of MC3T3-E1 Cells via BMP2/Smads Pathway and its Network Pharmacology Study

The study aimed to explore the potential of QiangJin mixture (QJM), a Chinese herbal compound prescription, in regulating MC3T3-E1 cell differentiation and to analyze the ingredients and therapeutic targets of QJM against osteoporosis based on network pharmacology. MC3T3-E1 cells were incubated with different concentrations of QJM-contained rat serum (5, 10, or 20%). After 14 days of cell culture, Alizarin Red staining was performed to assess the mineralization ability of osteoblasts. RT-qPCR was used to measure mRNA levels of osteogenesis-related genes. Western blot was conducted to measure protein levels of factors related to the BMP2/Smads pathway. Functional and pathway enrichment of overlapping targets for QJM and osteoporosis were analyzed using gene ontology and KEGG analyses. As shown by experimental results, QJM-contained serum led to calcium deposition, increased expression levels of osteogenesis-related genes, and activated BMP2/Smad/Runx2 signaling in MC3T3-E1 cells. A total of 125 active compounds and 162 disease-related targets were identified. The core targets were MAPK8, TP53, ESR1, STAT3, MAPK3, IL6, NFKB1, JUN, MAPK1 and AKT1. In conclusion, QJM promotes the osteogenic differentiation of MC3T3-E1 cells by activating the BMP2/Smads signaling. Additionally, QJM is an anti-osteoporotic mixture by regulating diverse therapeutic targets and signaling pathways.

Macrophage iron dyshomeostasis promotes aging-related renal fibrosis

Renal aging, marked by the accumulation of senescent cells and chronic low-grade inflammation, leads to renal interstitial fibrosis and impaired function. In this study, we investigate the role of macrophages, a key regulator of inflammation, in renal aging by analyzing kidney single-cell RNA sequencing data of C57BL/6J mice from 8 weeks to 24 months. Our findings elucidate the dynamic changes in the proportion of kidney cell types during renal aging and reveal that increased macrophage infiltration contributes to chronic low-grade inflammation, with these macrophages exhibiting senescence and activation of ferroptosis signaling. CellChat analysis indicates enhanced communications between macrophages and tubular cells during aging. Suppressing ferroptosis alleviates macrophage-mediated tubular partial epithelial-mesenchymal transition in vitro, thereby mitigating the expression of fibrosis-related genes. Using SCENIC analysis, we infer Stat1 as a key age-related transcription factor promoting iron dyshomeostasis and ferroptosis in macrophages by regulating the expression of Pcbp1, an iron chaperone protein that inhibits ferroptosis. Furthermore, through virtual screening and molecular docking from a library of anti-aging compounds, we construct a docking model targeting Pcbp1, which indicates that the natural small molecule compound Rutin can suppress macrophage senescence and ferroptosis by preserving Pcbp1. In summary, our study underscores the crucial role of macrophage iron dyshomeostasis and ferroptosis in renal aging. Our results also suggest Pcbp1 as an intervention target in aging-related renal fibrosis and highlight Rutin as a potential therapeutic agent in mitigating age-related renal chronic low-grade inflammation and fibrosis.

Adaptive covalently assembled thymopentin/hyaluronic acid based anti-inflammatory drug carrier with injectability and controlled release

Developing bioactive delivery carriers with anti-inflammatory functions, long-term administration, and controlled release of multiple drugs is highly desirable owing to disease persistence over an extended period. In this study, a dynamically induced covalent assembly approach was used to fabricate thymopentin (TP5)-based carrier particles (TGCP) with biocompatibility and autofluorescence. The size and dispersibility of TGCP can be modulated by non-covalent interactions with hyaluronic acid (HA), endowing the system with excellent injectability and synergistic anti-inflammatory activity. Interestingly, the carrier can load a wide range of guest molecules with varying solubilities and achieve controlled gradient release in pathological and physiological environments. In addition, traditional Chinese-medicine-loaded TGCP/HA can effectively reduce the level of the inflammatory factor IL-6, indicating its potential anti-inflammatory properties. The TP5/HA-based material possesses excellent carrier properties and immunoreactivity, making it attractive for reducing inflammation at disease sites and long-term drug delivery in various chronic diseases.

Small intestine submucosa decorated 3D printed scaffold accelerated diabetic bone regeneration by ameliorating the microenvironment

The 3D printed scaffolds constructed from polymers have shown significant potential in the field of bone defect regeneration. However, the efficacy of these scaffolds can be markedly reduced in certain pathological conditions like diabetes, where an altered inflammatory microenvironment and diminished small blood vessels complicate the integration of these polymers with the host tissue. In this study, the bioactivity of a 3D-printed poly(lactide-co-glycolide) (PLGA) scaffold is enhanced through the integration of hydroxyapatite (HA), icariin (ICA), and small intestine submucosa (SIS), a form of decellularized extracellular matrix (dECM). The decoration of SIS on the 3D-printed PLGA/HA/ICA scaffold not only improves the mechanical and degradative performance, but also extends the release of ICA from the scaffold. Both in vitro and in vivo studies demonstrate that this functionalized scaffold mitigates the persistent inflammatory conditions characteristic of diabetic bone defects through inducing macrophages towards the M2 phenotype. Additionally, the scaffold promotes angiogenesis by enhancing the migration and tube formation of vascular cells. Furthermore, the synergistic effects of ICA and SIS with the HA scaffolds contribute to the superior osteogenic induction capabilities. This functionalization approach holds significant promise in advancing the treatment of bone defects within the diabetic population, paving a step forward in the application of polymer-based 3D printing technologies in regenerative medicine.

Icariin alleviates oxygen-induced retinopathy by targeting microglia hexokinase 2

Retinopathy of prematurity (ROP) is a retinal disease-causing retinal neovascularization that can lead to blindness. Oxygen-induced retinopathy (OIR) is a widely used ROP animal model. Icariin (ICA) has anti-oxidative and anti-inflammation properties; however, whether ICA has a regulatory effect on OIR remains unclear. In this study, ICA alleviated pathological neovascularization, microglial activation and blood-retina barrier (BRB) damage in vivo. Further results indicated that endothelial cell tube formation, migration and proliferation were restored by ICA treatment in vitro. Proteomic microarrays and molecular mimicry revealed that ICA can directly bind to hexokinase 2 (HK2) and decrease HK2 protein expression in vivo and in vitro. In addition, ICA inhibited the AKT/mTOR/HIF1α pathway activation. The effects of ICA on pathological neovascularization, microglial activation and BRB damage disappeared after HK2 overexpression in vivo. Similarly, the endothelial cell function was revised after HK2 overexpression. HK2 overexpression reversed ICA-induced AKT/mTOR/HIF1α pathway inhibition in vivo and in vitro. Therefore, ICA prevented pathological angiogenesis in OIR in an HK2-dependent manner, implicating ICA as a potential therapeutic agent for ROP.

Insight of Chinese Herbal Medicine in Treating Osteoporosis: Achievements from 2013 to 2023

Osteoporosis is the most common bone metabolic disease, and it is becoming increasingly common as the global population ages. Osteoporosis and its complications, such as fractures and pain, negatively affect patient quality of life and easily lead to disability, placing enormous burdens on society. Although several anti-osteoporosis drugs are currently available, many adverse reactions have been observed during the long-term application of these drugs. Therefore, safer and more useful medications are urgently needed to replace those currently available. Chinese herbal medicine has been extensively used to treat osteoporosis, and the current literature confirms that such medicines have anti-osteoporosis effects, are safe, and have minimal side effects. Thus, Chinese herbal medicines are natural alternatives to pharmaceutical approaches to treating osteoporosis, and these medicines must be further developed and utilized. In this article, we review the mechanisms underlying the anti-osteoporosis effects of single herbal extracts and traditional Chinese medicine (TCM) formulas that have been elucidated since 2013, providing key evidence and support for future research on the anti-osteoporosis effects of Chinese herbal medicines. In addition, due to the complexity of the ingredients in Chinese herbal medicine, more thorough investigations are needed to determine the specific ingredients that are effective in osteoporosis treatment. Therefore, identifying the effective ingredients of Chinese herbal medicines will be a necessary focus in laboratory research and clinical application.

Enhancing osteoporosis treatment using a targeted, sustained-release drug delivery system based on macrocyclic amphiphile

Osteoporosis, a prevalent systemic bone metabolic disorder, primarily affects postmenopausal women and is characterized by increased bone fragility and a heightened risk of fractures. The efficacy of current osteoporosis treatments is often limited by non-specific drug targeting and undesirable off-target skeletal side effects. To address this challenge, we have developed a novel hydroxyapatite-responsive drug delivery system. This system utilizes a self-assembled p-phosphonatocalix[4]arene tetradodecyl ether (PC4A12C), engineered to specifically target and sustain the release of osteoporosis medication at sites of bone remodeling. Our focus centers on icariin (ICA), a drug known for its potent osteogenic properties and minimal adverse effects. In vitro, ICA-loaded PC4A12C (ICA@PC4A12C) demonstrated enhanced proliferation, differentiation, and mineralization in bone marrow mesenchymal stem cells (BMSCs). In vivo, ICA@PC4A12C exhibited superior efficacy in specifically targeting bone tissue, ensuring a controlled and slow release of icariin directly within the bone environment. In an osteoporosis mouse model, treatment with ICA@PC4A12C showed notable enhancement in osteogenic activity and a significant increase in bone density compared to ICA alone. These results demonstrate the potential of PC4A12C as an effective drug carrier in the development of advanced antiosteoporotic drug delivery systems.

Methacrylated Carboxymethyl Chitosan Scaffold Containing Icariin-Loaded Short Fibers for Antibacterial, Hemostasis, and Bone Regeneration

Bone defects typically result in bone nonunion, delayed or nonhealing, and localized dysfunction, and commonly used clinical treatments (i.e., autologous and allogeneic grafts) have limited results. The multifunctional bone tissue engineering scaffold provides a new treatment for the repair of bone defects. Herein, a three-dimensional porous composite scaffold with stable mechanical support, effective antibacterial and hemostasis properties, and the ability to promote the rapid repair of bone defects was synthesized using methacrylated carboxymethyl chitosan and icariin-loaded poly-l-lactide/gelatin short fibers (M-CMCS-SFs). Icariin-loaded SFs in the M-CMCS scaffold resulted in the sustained release of osteogenic agents, which was beneficial for mechanical reinforcement. Both the porous structure and the use of chitosan facilitate the effective absorption of blood and fluid exudates. Moreover, its superior antibacterial properties could prevent the occurrence of inflammation and infection. When cultured with bone mesenchymal stem cells, the composite scaffold showed a promotion in osteogenic differentiation. Taken together, such a multifunctional composite scaffold showed comprehensive performance in antibacterial, hemostasis, and bone regeneration, thus holding promising potential in the repair of bone defects and related medical treatments.

Epimedium Linn: A Comprehensive Review of Phytochemistry, Pharmacology, Clinical Applications and Quality Control

Epimedium genus is a traditional Chinese medicine, which has functions of tonifying kidney and yang, strengthening tendons and bones, dispelling wind and emoving dampness. It is mainly used for the treatment of impotence and spermatorrhea, osteoporosis, Parkinson's, Alzheimer's, and cardiovascular diseases. The aim of this review is to provide a systematic summary of the phytochemistry, pharmacology, and clinical applications of the Epimedium Linn. In this paper, the relevant literature on Epimedium Linn. was collected from 1987 to the present day, and more than 274 chemical constituents, including flavonoids, phenylpropanoids, lignans, phenanthrenes, and others, were isolated from this genus. Modern pharmacological studies have shown that Epimedium Linn. has osteoprotective, neuroprotective, cardiovascular protective, and immune enhancing pharmacological effects. In addition, Epimedium Linn. has been commonly used to treat osteoporosis, erectile dysfunction, hypertension and cardiovascular disease. In this paper, the distribution of resources, chemical compositions, pharmacological effects, clinical applications and quality control of Epimedium Linn. are progressed to provide a reference for further research and development of the resources of this genus.

Age-related alveolar bone maladaptation in adult orthodontics: finding new ways out

Compared with teenage patients, adult patients generally show a slower rate of tooth movement and more pronounced alveolar bone loss during orthodontic treatment, indicating the maladaptation of alveolar bone homeostasis under orthodontic force. However, this phenomenon is not well-elucidated to date, leading to increased treatment difficulties and unsatisfactory treatment outcomes in adult orthodontics. Aiming to provide a comprehensive knowledge and further inspire insightful understanding towards this issue, this review summarizes the current evidence and underlying mechanisms. The age-related abatements in mechanosensing and mechanotransduction in adult cells and periodontal tissue may contribute to retarded and unbalanced bone metabolism, thus hindering alveolar bone reconstruction during orthodontic treatment. To this end, periodontal surgery, physical and chemical cues are being developed to reactivate or rejuvenate the aging periodontium and restore the dynamic equilibrium of orthodontic-mediated alveolar bone metabolism. We anticipate that this review will present a general overview of the role that aging plays in orthodontic alveolar bone metabolism and shed new light on the prospective ways out of the impasse.

The SPI1/SMAD5 cascade in the promoting effect of icariin on osteogenic differentiation of MC3T3-E1 cells: a mechanism study

BACKGROUND

Dysregulation of osteogenic differentiation is a crucial event during osteoporosis. The bioactive phytochemical icariin has become an anti-osteoporosis candidate. Here, we elucidated the mechanisms underlying the promoting function of icariin in osteogenic differentiation.

METHODS

Murine pre-osteoblast MC3T3-E1 cells were stimulated with dexamethasone (DEX) to induce osteogenic differentiation, which was evaluated by an Alizarin Red staining assay and ALP activity measurement. The mRNA amounts of SPI1 and SMAD5 were detected by real-time quantitative PCR. Expression analysis of proteins, including osteogenic markers (OPN, OCN and RUNX2) and autophagy-associated proteins (LC3, Beclin-1, and ATG5), was performed by immunoblotting. The binding of SPI1 and the SMAD5 promoter was predicted by the Jaspar2024 algorithm and confirmed by chromatin immunoprecipitation (ChIP) experiments. The regulation of SPI1 in SMAD5 was examined by luciferase assays.

RESULTS

During osteogenic differentiation of MC3T3-E1 cells, SPI1 and SMAD5 were upregulated. Functionally, SPI1 overexpression enhanced autophagy and osteogenic differentiation of MC3T3-E1 cells, while SMAD5 downregulation exhibited opposite effects. Mechanistically, SPI1 could enhance SMAD5 transcription and expression. Downregulation of SMAD5 also reversed SPI1 overexpression-induced autophagy and osteogenic differentiation in MC3T3-E1 cells. In MC3T3-E1 cells under DEX stimulation, icariin increased SMAD5 expression by upregulating SPI1. Furthermore, icariin could attenuate SPI1 depletion-imposed inhibition of autophagy and osteogenic differentiation of MC3T3-E1 cells.

CONCLUSION

Our findings demonstrate that the SPI1/SMAD5 cascade, with the ability to enhance osteogenic differentiation, underlies the promoting effect of icariin on osteogenic differentiation of MC3T3-E1 cells.

Regulation of bone homeostasis by traditional Chinese medicine active scaffolds and enhancement for the osteoporosis bone regeneration

ETHNOPHARMACOLOGICAL RELEVANCE

The active ingredients of traditional Chinese medicine (TCM), such as naringin (NG), Eucommiol, isopsoralen, icariin, Astragalus polysaccharides, and chondroitin sulfate, contained in Drynariae Rhizoma, Eucommiae Cortex, Psoralea corylifolia, Herba Epimedii, Astragalus radix and deer antler, are considered promising candidates for enhancing the healing of osteoporotic defects due to their outstanding bone homeostasis regulating properties. They are commonly used to activate bone repair scaffolds.

AIM OF THE REVIEW

Bone repair scaffolds are inadequate to meet the demands of osteoporotic defect healing due to the lack of regulation of bone homeostasis. Therefore, selecting bone scaffolds activated with TCM to improve the therapeutic effect of repairing osteoporotic bone defects.

MATERIALS AND METHODS

To gather information on bone scaffold activated by traditional Chinese medicine, we conducted a thorough search of several scientific databases, including Google Scholar, Web of Science, Scifinder, Baidu Scholar, PubMed, and China National Knowledge Infrastructure (CNKI).

RESULTS

This review discusses the mechanism of TCM active ingredients in regulating bone homeostasis, including stimulating bone formation and inhibiting bone resorption process and the healing mechanism of traditional bone repair scaffolds activated by them for osteoporotic defect healing.

CONCLUSION

In general, the introduction of TCM active ingredients provides a novel therapeutic approach for modulating bone homeostasis and facilitating osteoporotic defect healing, and also offers a new strategy for design of other unconventional bone defect healing materials.

Bone-Targeted Supramolecular Nanoagonist Assembled by Accurate Ratiometric Herbal-Derived Therapeutics for Osteoporosis Reversal

Developing novel strategies for defeating osteoporosis has become a world-wide challenge with the aging of the population. In this work, novel supramolecular nanoagonists (NAs), constructed from alkaloids and phenolic acids, emerge as a carrier-free nanotherapy for efficacious osteoporosis treatment. These precision nanoagonists are formed through the self-assembly of berberine (BER) and chlorogenic acid (CGA), utilizing noncovalent electrostatic, π-π, and hydrophobic interactions. This assembly results in a 100% drug loading capacity and stable nanostructure. Furthermore, the resulting weights and proportions of CGA and BER within the NAs are meticulously controlled with strong consistency when the CGA/BER assembly feed ratio is altered from 1:1 to 1:4. As anticipated, our NAs themselves could passively target osteoporotic bone tissues following prolonged blood circulation, modulate Wnt signaling, regulate osteogenic differentiation, and ameliorate bone loss in ovariectomy-induced osteoporotic mice. We hope this work will open a new strategy to design efficient herbal-derived Wnt NAs for dealing with intractable osteoporosis.

Promoting osteogenesis and bone regeneration employing icariin-loaded nanoplatforms

There is an increasing demand for innovative strategies that effectively promote osteogenesis and enhance bone regeneration. The critical process of bone regeneration involves the transformation of mesenchymal stromal cells into osteoblasts and the subsequent mineralization of the extracellular matrix, making up the complex mechanism of osteogenesis. Icariin's diverse pharmacological properties, such as anti-inflammatory, anti-oxidant, and osteogenic effects, have attracted considerable attention in biomedical research. Icariin, known for its ability to stimulate bone formation, has been found to encourage the transformation of mesenchymal stromal cells into osteoblasts and improve the subsequent process of mineralization. Several studies have demonstrated the osteogenic effects of icariin, which can be attributed to its hormone-like function. It has been found to induce the expression of BMP-2 and BMP-4 mRNAs in osteoblasts and significantly upregulate Osx at low doses. Additionally, icariin promotes bone formation by stimulating the expression of pre-osteoblastic genes like Osx, RUNX2, and collagen type I. However, icariin needs to be effectively delivered to bone to perform such promising functions.Encapsulating icariin within nanoplatforms holds significant promise for promoting osteogenesis and bone regeneration through a range of intricate biological effects. When encapsulated in nanofibers or nanoparticles, icariin exerts its effects directly at the cellular level. Recalling that inflammation is a critical factor influencing bone regeneration, icariin's anti-inflammatory effects can be harnessed and amplified when encapsulated in nanoplatforms. Also, while cell adhesion and cell migration are pivotal stages of tissue regeneration, icariin-loaded nanoplatforms contribute to these processes by providing a supportive matrix for cellular attachment and movement. This review comprehensively discusses icariin-loaded nanoplatforms used for bone regeneration and osteogenesis, further presenting where the field needs to go before icariin can be used clinically.

Smart osteoclasts targeted nanomedicine based on amorphous CaCO3 for effective osteoporosis reversal

BACKGROUND

Osteoporosis is characterized by an imbalance in bone homeostasis, resulting in the excessive dissolution of bone minerals due to the acidified microenvironment mediated by overactive osteoclasts. Oroxylin A (ORO), a natural flavonoid, has shown potential in reversing osteoporosis by inhibiting osteoclast-mediated bone resorption. The limited water solubility and lack of targeting specificity hinder the effective accumulation of Oroxylin A within the pathological environment of osteoporosis.

RESULTS

Osteoclasts' microenvironment-responsive nanoparticles are prepared by incorporating Oroxylin A with amorphous calcium carbonate (ACC) and coated with glutamic acid hexapeptide-modified phospholipids, aiming at reinforcing the drug delivery efficiency as well as therapeutic effect. The obtained smart nanoparticles, coined as OAPLG, could instantly neutralize acid and release Oroxylin A in the extracellular microenvironment of osteoclasts. The combination of Oroxylin A and ACC synergistically inhibits osteoclast formation and activity, leading to a significant reversal of systemic bone loss in the ovariectomized mice model.

CONCLUSION

The work highlights an intelligent nanoplatform based on ACC for spatiotemporally controlled release of lipophilic drugs, and illustrates prominent therapeutic promise against osteoporosis.

Targeting bone homeostasis regulation: potential of traditional Chinese medicine flavonoids in the treatment of osteoporosis

Osteoporosis is a systemic metabolic disease characterized by disrupted bone formation/resorption and homeostasis. Flavonoids extracted from traditional Chinese medicinal plants regulate bone homeostasis by intervening in differentiating bone marrow mesenchymal stem cells, balancing the bone immune system, inhibiting oxidative stress response, and reversing iron overload. The target molecules and signaling pathways, such as Wnt/β-catenin and OPG/RANKL/RANK, directly affect osteoblast/osteoclast activity, exhibiting significant potential in the treatment of OP. Therefore, this study presents a systematic review of the recent literature to provide comprehensive information on the traditional Chinese medicine flavonoids involved in the regulation of bone homeostasis. Also, the molecular mechanisms and pharmacological uses of these metabolites are summarized, and their clinical translation and development potential are discussed.

Impact of surface biofunctionalization strategies on key effector cells response in polyacrylamide hydrogels for bone regeneration

Despite the clinical prevalence of various bone defect repair materials, a full understanding of their influence on bone repair and regeneration remains elusive. This study focuses on poly(acrylamide) (PAAm) hydrogels, popular 2D model substrates, which have regulable mechanical properties within physiological. However, their bio-inert nature requires surface biofunctionalization to enhance cell-material interactions and facilitate the study of bone repair mechanisms. We utilized PAAm hydrogels of varying stiffness (18, 76 and 295 kPa), employed sulfosuccinimidyl-6-(4'-azido-2'-nitropheny-lamino) hexanoate (sulfo-SANPAH) and N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride/N-hydroxysuccinimidyl acrylate (EDC/NHS) as crosslinkers, and cultured macrophages, endothelial cells, and bone mesenchymal stem cells on these hydrogels. Our findings indicated that sulfo-SANPAH's crosslinking efficiency surpassed that of EDC/NHS, irrespective of pore size and stiffness. Importantly, we observed that the stiffness and surface biofunctionalization method of hydrogels significantly impacted cell adhesion and proliferation. The collagen-modified hydrogels by EDC/NHS strategy failed to support the normal biological behavior of bone mesenchymal stem cells and hindered endothelial cell spreading. In contrast, these modified hydrogels by the sulfo-SANPAH method showed good cytocompatibility with the three types of cells. This study underscores the critical role of appropriate conjugation strategies for PAAm hydrogels, providing valuable insights for hydrogel surface modification in bone repair and regeneration research.

Astragaloside IV alleviates macrophage senescence and d-galactose-induced bone loss in mice through STING/NF-κB pathway

BACKGROUND

Senile osteoporosis (SOP) is an age-related metabolic bone disease that currently lacks specific therapeutic interventions. Thus, this study aimed to investigate the effect of Astragaloside IV (AS-IV) on macrophage senescence, bone marrow mesenchymal stem cell (BMSC) osteogenesis, and SOP progression.

METHODS

A senescent macrophage model was established and treated with varying concentrations of AS-IV. Cell activity was measured using the CCK8 assay. The senescence levels of macrophages were evaluated through β-galactosidase staining, PCR, and immunofluorescence. Macrophage mitochondrial function was assessed using ROS and JC-1 staining. Macrophage polarization was evaluated through PCR, Western blot, and immunofluorescence. The inhibitory effects of AS-IV on macrophage senescence were investigated using Western blot analysis. Furthermore, the effects of macrophage conditioned medium (CM) on BMSCs osteogenic were detected using ALP, alizarin red, and PCR.

RESULTS

AS-IV inhibited macrophage senescence and M1 polarization, alleviated mitochondrial dysfunction, and promoted M2 polarization. Mechanistically, it suppressed the STING/NF-κB pathway in H2O2-activated macrophages. Conversely, the STING agonist c-di-GMP reversed the effects of AS-IV on macrophage senescence. Additionally, AS-IV-induced macrophage CM promoted BMSC osteogenic differentiation. In vivo, AS-IV treatment ameliorated aberrant bone microstructure and bone mass loss in the SOP mouse model, inhibited macrophage senescence, and promoted M2 polarization.

CONCLUSIONS

By modulating the STING/NF-κB signaling pathway, AS-IV potentially inhibited macrophage senescence and stimulated osteogenic differentiation of BMSCs, thus exerting an anti-osteoporotic effect. Consequently, AS-IV may serve as an effective therapeutic candidate for the treatment of osteoporosis.

Anti-aging effects of icariin and the underlying mechanisms: A mini-review

Aging is an extremely intricate and progressive phenomenon that is implicated in many physiological and pathological conditions. Icariin (ICA) is the main active ingredient of Epimedium and has exhibited multiple bioactivities, such as anti-tumor, neuroprotective, antioxidant, anti-inflammatory, and anti-aging properties. ICA could extend healthspan in both invertebrate and vertebrate models. In this review, the roles of ICA in protection from declined reproductive function, neurodegeneration, osteoporosis, aging intestinal microecology, and senescence of cardiovascular system will be summarized. Furthermore, the underlying mechanisms of ICA-mediated anti-aging effects will be introduced. Finally, we will discuss some key aspects that constrain the usage of ICA in clinical practice and the corresponding strategies to solve these issues.

Icariin-loaded 3D-printed porous Ti6Al4V reconstruction rods for the treatment of necrotic femoral heads

Avascular necrosis of the femoral head is a prevalent hip joint disease. Due to the damage and destruction of the blood supply of the femoral head, the ischemic necrosis of bone cells and bone marrow leads to the structural changes and the collapse of the femoral head. In this study, an icariin-loaded 3D-printed porous Ti6Al4V reconstruction rod (referred to as reconstruction rod) was prepared by 3D printing technology. The mechanical validity of the reconstruction rod was verified by finite element analysis. Through infilling of mercapto hyaluronic acid hydrogel containing icariin into the porous structure, the loading of icariin was achieved. The biological efficacy of the reconstruction rod was confirmed through in vitro cell experiments, which demonstrated its ability to enhance MC3T3-E1 cell proliferation and facilitate cellular adhesion and spreading. The therapeutic efficacy of the reconstruction rod was validated in vivo through a femoral head necrosis model using animal experiments. The results demonstrated that the reconstruction rod facilitated osteogenesis and neovascularization, leading to effective osseointegration between bone and implant. This study provides innovative strategy for the treatment of early avascular necrosis of the femoral head. STATEMENT OF SIGNIFICANCE: The bioactivity of medical titanium alloy implants plays an important role in bone tissue engineering. This study proposed a medicine and device integrated designed porous Ti6Al4V reconstruction rod for avascular necrosis of the femoral head, whose macroscopic structure was customized by selective laser melting. The bionic porous structure of the reconstruction rod promoted the growth of bone tissue and formed an effective interface integration. Meanwhile, the loaded icariin promoted new bone and vascular regeneration, and increased the bone mass and bone density. Therefore, the implantation of reconstruction rod interfered with the further development of necrosis and provided a positive therapeutic effect. This study provides innovative strategies for the treatment of early avascular necrosis of femoral head.