Fatty acid is a potential agent for bone tissue induction: In vitro and in vivo approach

Unraveling the molecular and immunological landscape: Exploring signaling pathways in osteoporosis

Osteoporosis, characterized by compromised bone density and microarchitecture, represents a significant global health challenge, particularly in aging populations. This comprehensive review delves into the intricate signaling pathways implicated in the pathogenesis of osteoporosis, providing valuable insights into the pivotal role of signal transduction in maintaining bone homeostasis. The exploration encompasses cellular signaling pathways such as Wnt, Notch, JAK/STAT, NF-κB, and TGF-β, all of which play crucial roles in bone remodeling. The dysregulation of these pathways is a contributing factor to osteoporosis, necessitating a profound understanding of their complexities to unveil the molecular mechanisms underlying bone loss. The review highlights the pathological significance of disrupted signaling in osteoporosis, emphasizing how these deviations impact the functionality of osteoblasts and osteoclasts, ultimately resulting in heightened bone resorption and compromised bone formation. A nuanced analysis of the intricate crosstalk between these pathways is provided to underscore their relevance in the pathophysiology of osteoporosis. Furthermore, the study addresses some of the most crucial long non-coding RNAs (lncRNAs) associated with osteoporosis, adding an additional layer of academic depth to the exploration of immune system involvement in various types of osteoporosis. Finally, we propose that SKP1 can serve as a potential biomarker in osteoporosis.

Effects of Sapindus mukorossi Seed Oil on Bone Healing Efficiency: An Animal Study

Natural products have attracted great interest in the development of tissue engineering. Recent studies have demonstrated that unsaturated fatty acids found in natural plant seed oil may exhibit positive osteogenic effects; however, few in vivo studies have focused on the use of plant seed oil for bone regeneration. The aim of this study is to investigate the effects of seed oil found in Sapindus mukorossi (S. mukorossi) on the osteogenic differentiation of mesenchymal stem cells and bone growth in artificial bone defects in vivo. In this study, Wharton-jelly-derived mesenchymal stem cells (WJMSCs) were co-cultured with S. mukorossi seed oil. Cellular osteogenic capacity was assessed using Alizarin Red S staining. Real-time PCR was carried out to evaluate ALP and OCN gene expression. The potential of S. mukorossi seed oil to enhance bone growth was assessed using an animal model. Four 6 mm circular defects were prepared at the parietal bone of New Zealand white rabbits. The defects were filled with hydrogel and hydrogel-S. mukorossi seed oil, respectively. Quantitative analysis of micro-computed tomography (Micro-CT) and histological images was conducted to compare differences in osteogenesis between oil-treated and untreated samples. Although our results showed no significant differences in viability between WJMSCs treated with and without S. mukorossi seed oil, under osteogenic conditions, S. mukorossi seed oil facilitated an increase in mineralized nodule secretion and upregulated the expression of ALP and OCN genes in the cells (p < 0.05). In the animal study, both micro-CT and histological evaluations revealed that new bone formation in artificial bone defects treated with S. mukorossi seed oil were nearly doubled compared to control defects (p < 0.05) after 4 weeks of healing. Based on these findings, it is reasonable to suggest that S. mukorossi seed oil holds promise as a potential candidate for enhancing bone healing efficiency in bone tissue engineering.

Protaetia brevitarsis Extract Attenuates RANKL-Induced Osteoclastogenesis by Inhibiting the JNK/NF-κB/PLCγ2 Signaling Pathway

Protaetia brevitarsis (PB)-derived bioactive substances have been used as food and medicine in many Asian countries because of their antioxidant, antidiabetic, anti-cancer, and hepatoprotective properties. However, the effect of PB extracts (PBE) on osteoclast differentiation is unclear. In this study, we investigated the effect of PBE on RANKL-induced osteoclastogenesis in mouse bone marrow-derived macrophages (BMMs). To investigate the cytotoxicity of PBE, the viability of BMMs was confirmed via MTT assay. Tartrate-resistant acid phosphatase (TRAP) staining and pit assays were performed to confirm the inhibitory effect of PBE on osteoclast differentiation and bone resorption. The expression levels of osteoclast differentiation-related genes and proteins were evaluated using quantitative real-time PCR and Western blotting. PBE attenuated osteoclastogenesis in BMMs in TRAP and pit assays without cytotoxicity. The expression levels of osteoclast marker genes and proteins induced by RANKL were decreased after PBE treatment. PBE suppressed osteoclastogenesis by inhibiting the RANKL-induced activated JNK/NF-κB/PLCγ2 signaling pathway and the expression of NFATc1 and c-Fos. Collectively, these results suggest that PBE could be a potential therapeutic strategy or functional product for osteoclast-related bone disease.

The hepatitis B virus promotes the progression of non-alcoholic fatty liver disease through incomplete autophagy

Hepatitis B virus (HBV) infection is still a serious public health problem. In recent years, with the increasing incidence of chronic hepatitis B (CHB) combined with nonalcoholic fatty liver disease (NAFLD), a more in-depth exploration of the pathogenesis of CHB combined with NAFLD is required. HBV can induce autophagy and use to increase replication. The removal of fat by autophagy, also known as lipophagy, is also currently considered an alternative pathway for lipid metabolism in liver cells. This degradation of autophagy prevents hepatotoxicity and steatosis. However, it is not known whether there is a correlation between HBV-related autophagy and the progression of NAFLD. We explored how HBV affects disease progression in NAFLD should be " and determined whether it is associated with HBV-associated autophagy. In this study, we constructed HBV-TG mouse high-fat diet (HFD) models and controls, and the results showed that the presence of HBV promoted the occurrence of NAFLD. We also demonstrated that HBV promotes lipid droplet accumulation in hepatocytes using HBV-stable expression cell lines HepG2.2.15 and AML12-HBV. In addition, this study also found that exogenous OA supplementation reduced HBV replication. We further studied the mechanism and found that HBV-related autophagy can promote the absorption of liver cells to lipid droplets. It can reduce the decomposition of lipid droplets by inhibiting the function of autophagolysosome, and eventually lead to the accumulation of lipid droplets in hepatocytes. In a word, HBV promotes the progression of NAFLD by increasing lipid accumulation in hepatocytes through incomplete autophagy.

Regenerative repair of full thickness skin wound assisted by dual crosslinking percolative gel casting maneuvered alginate hydrogel embedded with honey ghee blend resembles standard cutaneous properties

We report synergism in scarless cutaneous wound repair by alginate hydrogel (HGSAG) embedded with an optimized blend of characterized Jamun honey and characterized indigenously prepared ghee. Thorough screening and characterization of honey and ghee are carried out followed by obtaining a novel dual crosslinking percolative gel casting fabrication method to come up with HGSAG showing superior chemical stability, and mechanical strength (Nanoindentation study; lowest stiffness: 0.71 ± 0.19 μN/nm), and surface morphology (SEM; highest roughness: 0.13 ± 0.04 μm) to other variants. In vitro swelling study and degradation behavior study show intermediate swelling (swelling index: 0.59 ± 0.008 in 98 h) and required restricted degradation (PBS: 73.38 ± 0.55%, DMEM: 83.48 ± 0.69% in 10 days) for HGSAG which is necessary for providing nutrients to cells and in vivo therapeutic efficacy. We observe the remarkable antibacterial efficacy of HGSAG against Staphylococcus mutans and Escherichia coli. This particular substrate also shows decent 3T3 fibroblasts viability, cell-cell communication followed by cell-matrix interaction, and proliferation compared to other variants. Molecular gene expression studies by quantitative RT-PCR technique reveal strong upregulation of collagen I, CD26, and TGF-β3 while downregulation in the case of TGF-β1 which eventually substantiates scarless wound healing potential of HGSAG. Wound closure kinetics is most rapidly and successfully underpinned by HGSAG while compared to other alternatives including marketed healing patches. Regular close monitoring using histopathological studies and real-time imaging by Swept-Source Optical Coherence Tomography of in vivo wound model treated with HGSAG come up with the fascinating result of scarless healing (HGSAG treated epithelial thickness: 62.96 ± 0.67 μm, unwounded akin epithelial thickness: 62.56 ± 0.34 μm) within 12 days of wounding. Thus, the work highlights modified and stabilized alginate hydrogel embedded with honey and ghee blend as a potential scarless full-thickness cutaneous wound healing bio-scaffold.

Resolution of inflammation in bone regeneration: From understandings to therapeutic applications

Impaired bone healing occurs in 5-10% of cases following injury, leading to a significant economic and clinical impact. While an inflammatory response upon injury is necessary to facilitate healing, its resolution is critical for bone tissue repair as elevated acute or chronic inflammation is associated with impaired healing in patients and animal models. This process is governed by important crosstalk between immune cells through mediators that contribute to resolution of inflammation in the local healing environment. Approaches modulating the initial inflammatory phase followed by its resolution leads to a pro-regenerative environment for bone regeneration. In this review, we discuss the role of inflammation in bone repair, the negative impact of dysregulated inflammation on bone tissue regeneration, and how timely resolution of inflammation is necessary to achieve normal healing. We will discuss applications of biomaterials to treat large bone defects with a specific focus on resolution of inflammation to modulate the immune environment following bone injury, and their observed functional benefits. We conclude the review by discussing future strategies that could lead to the realization of anti-inflammatory therapeutics for bone tissue repair.

Biomaterials and Adipose-Derived Mesenchymal Stem Cells for Regenerative Medicine: A Systematic Review

The use of biological templates for the suitable growth of adipose-derived mesenchymal stem cells (AD-MSC) and “neo-tissue” construction has exponentially increased over the last years. The bioengineered scaffolds still have a prominent and biocompatible framework playing a role in tissue regeneration. In order to supply AD-MSCs, biomaterials, as the stem cell niche, are more often supplemented by or stimulate molecular signals that allow differentiation events into several strains, besides their secretion of cytokines and effects of immunomodulation. This systematic review aims to highlight the details of the integration of several types of biomaterials used in association with AD-MSCs, collecting notorious and basic data of in vitro and in vivo assays, taking into account the relevance of the interference of the cell lineage origin and handling cell line protocols for both the replacement and repairing of damaged tissues or organs in clinical application. Our group analyzed the quality and results of the 98 articles selected from PubMed, Scopus and Web of Science. A total of 97% of the articles retrieved demonstrated the potential in clinical applications. The synthetic polymers were the most used biomaterials associated with AD-MSCs and almost half of the selected articles were applied on bone regeneration.

Double-Controlled Release of Poorly Water-Soluble Paliperidone Palmitate from Self-Assembled Albumin-Oleic Acid Nanoparticles in PLGA in situ Forming Implant

Purpose

To investigate the effects of solvents on the formation of self-assembled nanonization of albumin-oleic acid conjugates (AOCs) using a solvent exchange mechanism for the construction of in situ forming implants (ISFI).

Methods

A poorly water-soluble drug, paliperidone palmitate (PPP), was chosen as the model drug. AOC was synthesized with the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) reaction. Dichloromethane, tetrahydrofuran, ethanol, N-methyl-2-pyrrolidone, dimethyl sulfoxide, and deionized water were selected to investigate the formation of self-assembled AOC nanoparticles (AONs). The volume ratios of organic solvents against water could determine the miscibility, injectability, and in situ nanonizing capability without aggregation.

Results

As the polarity of the organic solvents increased, the AONs exhibited a spherical shape, and the larger the volume of the solvent, the smaller the size of the AONs. To use AOC in ISFI for controlled release of PPP, poly(d,l-lactide-co-glycolide) (PLGA) was combined with the AOC in 2 mL of N-methyl-2-pyrrolidone and water solution (1.8/0.2 ratio). The release rates of all formulations exhibited similar curve patterns overall but were more controlled in decreasing order as follows: AOC, PLGA, and AOC/PLGA for 14 days.

Conclusion

A combined formulation of AOC and PLGA was found to effectively control the initial burst release of the drug.

Oleuropein-Laded Ufasomes Improve the Nutraceutical Efficacy

Ufasomes are unsaturated fatty acid liposomes made up of oleic and linoleic acids, natural components required in various biological processes. This kind of nanocarrier is characterized by a simple and dynamic structure and is able to improve the bioavailability of unsaturated fatty acids. The aim of this investigation was to evaluate ufasomes as natural compound delivery systems to deliver oleuropein and improve its antioxidant activity. Oleuropein is a phenolic compound mainly present in olives and olive oil, with several biological properties, such as the antioxidant activity. However, to improve their biological activity, antioxidant compounds should be able to cross cell membranes and uniformly incorporate in cells. Because of the great similarity between their constituents and cell membranes, ufasomes could be advantageous carriers for oleuropein delivery. The physico-chemical characteristics of ufasomes were investigated. A regular shape was shown by transmission electron microscopy studies, while the mean sizes were dependent on the ufasomes composition. In vitro studies highlighted that empty ufasomes did not lead to cell mortality at the tested concentrations and a good carrier internalization in CaCo-2 cells, further studies in vitro studies demonstrated that oleuropein-loaded ufasomes were able to enhance the antioxidant activity of the free active substance making this carrier a suitable one for nutraceutical application.

Decellularized bone matrix/oleoyl chitosan derived supramolecular injectable hydrogel promotes efficient bone integration

Hydrogels derived from decellularized extracellular matrix (ECM) have been widely used as a bioactive matrix for facilitating functional bone tissue regeneration. However, its poor mechanical strength and fast degradation restricts the extensive use for clinical application. Herein, we present a crosslinked decellularized bone ECM (DBM) and fatty acid modified chitosan (oleoyl chitosan, OC) based biohybrid hydrogel (DBM/OC) for delivering human amnion-derived stem cells (HAMSCs) for bone regeneration. DBM/OC hydrogel were benchmarked against collagen-I/OC (Col-I/OC) based hydrogel in terms of their morphological characteristics, rheological analysis, and biological performances. DBM/OC hydrogel with its endogenous growth factors recapitulates the nanofibrillar 3D tissue microenvironment with improved mechanical strength and also exhibited antimicrobial potential along with superior proliferation/differentiation ability. HAMSCs encapsulation potential of DBM/OC hydrogel was established by well spread cytoskeleton morphology post 14 days of cultivation. Further, ex-vivo chick chorioallantoic membrane (CAM) assay revealed excellent neovascularization potential of DBM/OC hydrogel. Subcutaneously implanted DBM/OC hydrogel did not trigger any severe immune response or infection in the host after 21 days. Also, DBM/OC hydrogels and HAMSCs encapsulated DBM/OC hydrogels were implanted at the tibial defect in a rabbit model to assess the bone regeneration ability. Quantitative micro-CT and histomorphological analysis demonstrated that HAMSCs encapsulated DBM/OC hydrogel can support more mature mineralized bone formation at the defect area compared to DBM/OC hydrogel or SHAM. These findings manifested the efficacy of DBM/OC hydrogel as a functional cell-delivery vehicle and osteoinductive template to accelerate bone regeneration.

Distinguish fatty acids impact survival, differentiation and cellular function of periodontal ligament fibroblasts

Alveolar bone (AB) remodeling is necessary for the adaption to mechanical stimuli occurring during mastication and orthodontic tooth movement (OTM). Thereby, bone degradation and assembly are strongly regulated processes that can be altered in obese patients. Further, increased fatty acids (FA) serum levels affect bone remodeling cells and we, therefore, investigated whether they also influence the function of periodontal ligament fibroblast (PdLF). PdLF are a major cell type regulating the differentiation and function of osteoblasts and osteoclasts localized in the AB. We stimulated human PdLF (HPdLF) in vitro with palmitic (PA) or oleic acid (OA) and analyzed their metabolic activity, growth, survival and expression of osteogenic markers and calcium deposits. Our results emphasize that PA increased cell death of HPdLF, whereas OA induced their osteoblastic differentiation. Moreover, quantitative expression analysis of OPG and RANKL revealed altered levels in mechanically stimulated PA-treated HPdLF. Furthermore, osteoclasts stimulated with culture medium of mechanical stressed FA-treated HPdLF revealed significant changes in cell differentiation upon FA-treatment. For the first time, our results highlight a potential role of specific FA in the function of HPdLF-modulated AB remodeling and help to elucidate the complex interplay of bone metabolism, mechanical stimulation and obesity-induced alterations.

Therapeutic potentials and modulatory mechanisms of fatty acids in bone

Bone metabolism is a lifelong process that includes bone formation and resorption. Osteoblasts and osteoclasts are the predominant cell types associated with bone metabolism, which is facilitated by other cells such as bone marrow mesenchymal stem cells (BMMSCs), osteocytes and chondrocytes. As an important component in our daily diet, fatty acids are mainly categorized as long‐chain fatty acids including polyunsaturated fatty acids (LCPUFAs), monounsaturated fatty acids (LCMUFAs), saturated fatty acids (LCSFAs), medium‐/short‐chain fatty acids (MCFAs/SCFAs) as well as their metabolites. Fatty acids are closely associated with bone metabolism and associated bone disorders. In this review, we summarized the important roles and potential therapeutic implications of fatty acids in multiple bone disorders, reviewed the diverse range of critical effects displayed by fatty acids on bone metabolism, and elucidated their modulatory roles and mechanisms on specific bone cell types. The evidence supporting close implications of fatty acids in bone metabolism and disorders suggests fatty acids as potential therapeutic and nutritional agents for the treatment and prevention of metabolic bone diseases.

Drug Leaching Properties of Vancomycin Loaded Mesoporous Hydroxyapatite as Bone Substitutes

Infections after bone reconstructive surgery become an authentic therapeutic and economic issue when it comes to a modern health care system. In general; infected bone defects are regarded as contraindications for bone grafting. Since the pathogens develop a biofilm on the inner surface of the bone; local delivery of antibiotics becomes more important. The present work focuses on the synthesis of Mesoporous Hydroxyapatite (MPHAP) loaded with drug Vancomycin (Van) and to investigate its loading and leaching ability in phosphate buffer solution (PBS), to be used for post-operative infections. The effect of pore size on MPHAP was analyzed using different fatty acids as organic modifiers. The impacts of various fatty acids chain length on the morphology and pore size were studied. A simple impregnation technique with optimized conditions ensured a high antibiotic loading (up to 0.476 + 0.0135 mg/mL), with a complete in vitro release obtained within 50 h.

Differential effects of reticulophagy and mitophagy on nonalcoholic fatty liver disease

Autophagy affects the pathological progression of non-alcoholic fatty liver disease (NAFLD); however, the precise role of autophagy in NAFLD remains unclear. In this study, we want to identify the role of autophagy including reticulophagy and mitophagy in NAFLD pathogenesis. When HepG2 cells were treated with 400 μM oleic acid (OA), increased reticulophagy was induced 8 h after treatment, which correlated with an anti-apoptotic response as shown by the activation of the PI3K/AKT pathway, an increase in BCL-2 expression, and the downregulation of OA-induced lipotoxicity. When treated with OA for 24 h, DRAM expression-dependent mitophagy resulted in increased apoptosis in HepG2 cells. Inhibition of reticulophagy aggravated and increased lipotoxicity-induced apoptosis 8 h after treatment; however, the inhibition of mitophagy decreased hepatocyte apoptosis after 24 h of OA treatment. Results from the analysis of patient liver samples showed that autophagic flux increased in patients with mild or severe NAFL. PI3K/AKT phosphorylation was observed only in samples from patients with low-grade steatosis, whereas DRAM expression was increased in samples from patients with high-grade steatosis. Together, our results demonstrate that reticulophagy and mitophagy are independent, sequential events that influence NAFLD progression, which opens new avenues for investigating new therapeutics in NAFLD.