All-in-one strategy to develop a near-infrared triggered multifunctional bioactive magnesium phosphate bone cement for bone repair.

Bone cement is widely used in clinical with optimistic filling and mechanical properties. However, the setting time of bone cement is difficult to accurately control, and the existing bone cements exhibit limited therapeutic functionalities. In response to these challenges, we designed and synthesized Nd-doped whitlockite (Nd-WH), endowing bone cement with photothermal-responsive and fluorescence imaging capabilities. The doping amount and photothermal properties of Nd-doped whitlockite were studied, and the composite bone cement was prepared. The results showed that the setting time of bone cement could be regulated by near infrared irradiation, and the multiple functions of promoting osteogenic differentiation, antibacterial and anti-tumor could be realized by adjusting the power and irradiation time of near infrared. By incorporating Nd-doped whitlockite and bone cement, we developed an all-in-one strategy to achieve setting time control, enhanced osteogenic ability, tumor cell clearance, bacterial clearance, and bone tissue regeneration. The optimized physical and mechanical properties of composite bone cement ensure adaptability and plasticity. In vitro and in vivo experiments validated the effectiveness of this bone cement platform for bone repair, tumor cell clearance and bacterial clearance. The universal methods to regulate the setting time and function of bone cement by photothermal effect has potential in orthopedic surgery and is expected to be a breakthrough in the field of bone defect repair. Further research and clinical validation are needed to ensure its safety, efficacy and sustainability. STATEMENT OF SIGNIFICANCE: Bone cement is a valuable clinical material. However, the setting time of bone cement is difficult to control, and the therapeutic function of existing bone cement is limited. Various studies have shown that the bone repair capacity of bone cements can be enhanced by synergistic stimulatory effects in vivo and ex vivo. Unfortunately, most of the existing photothermal conversion materials are non-degradable and poorly biocompatible. This study provides a bone-like photothermal conversion material with photothermal response and fluorescence imaging properties, and constructed a platform for integrated regulation of the setting time of bone cement and diversification of its functions. Therefore, it helps to design multi-functional bone repair materials that are more convenient and effective in clinical operation.

Injectable photocrosslinking spherical hydrogel-encapsulated targeting peptide-modified engineered exosomes for osteoarthritis therapy.

Osteoarthritis (OA) is a common degenerative joint disease urgently needing effective treatments. Bone marrow mesenchymal stromal cell-derived exosomes (Exo) are considered good drug carriers whereas they have limitations such as fast clearance and low retention. This study aimed to overcome the limitations of Exo in drug delivery using multiple strategies. Novel photocrosslinking spherical gelatin methacryloyl hydrogel (GelMA)-encapsulated cartilage affinity WYRGRL (W) peptide-modified engineered Exo were developed for OA treatment and the performance of the engineered Exo (W-Exo@GelMA) loaded with a small inhibitor LRRK2-IN-1 (W-Exo-L@GelMA) was investigated in vitro and in vivo. The W-Exo-L@GelMA showed an effective targeting effect on chondrocytes and a pronounced action on suppressing catabolism and promoting anabolism in vitro. Moreover, W-Exo-L@GelMA remarkably inhibited OA-related inflammation and immune gene expression, rescuing the IL-1ß-induced transcriptomic responses. With enhanced retention in the joint, W-Exo-L@GelMA demonstrated superior anti-OA activity and cartilage repair ability in the OA murine model. The therapeutic effect was validated in the cultured human OA cartilage. In conclusion, photocrosslinking spherical hydrogel-encapsulated targeting peptide-modified engineered Exo exhibit notable potential in OA therapy. Engineering Exo by a series of strategies enhanced the targeting ability and retention and cartilage-targeting and Exo-mediated drug delivery may offer a novel strategy for OA treatment.Clinical trial registration: Not applciable.

Eriocalyxin B ameliorated Crohn's disease-like colitis by restricting M1 macrophage polarization through JAK2/STAT1 signalling.

BACKGROUND AND AIMS: M1 polarization of macrophages in the intestine is an important maintenance factor of the inflammatory response in Crohn's disease (CD). Eriocalyxin B (EriB) is a natural medicine that antagonizes inflammation. Our study aimed to determine the effects of EriB on CD-like colitis in mice, as well as the possible mechanism. METHODS: 2,4,6-trinitrobenzene sulfonic acid (TNBS) mice and Il-10-/- mice were used as CD animal models, and the therapeutic effect of EriB on CD-like colitis in mice was addressed by the disease activity index (DAI) score, weight change, histological analysis and flow cytometry assay. To assess the direct role of EriB in regulating macrophage polarization, bone marrow-derived macrophages (BMDMs) were induced to M1 or M2 polarization separately. Molecular docking simulations and blocking experiments were performed to explore the potential mechanisms by which EriB regulates the macrophage polarization. RESULTS: EriB treatment reduced body weight loss, DAI score and histological score, demonstrating the improvement of colitis symptoms in mice. In vivo and in vitro experiments both showed that EriB decreased the M1 polarization of macrophages, and suppressed the release of proinflammatory cytokines (IL-1ß, TNF-α and IL-6) in mouse colons and BMDMs. The activation of Janus kinase 2/signal transducer and activator of transcription 1 (JAK2/STAT1) signals could be inhibited by EriB, which may be related to the regulation of EriB on M1 polarization. CONCLUSIONS: EriB inhibits the M1 polarization of macrophages by attenuating the JAK2/STAT1 pathway, which partially explains the potential mechanism by which EriB ameliorates colitis in mice, and provides a new regimen for the clinical treatment of CD.

[Effect of miR-199a regulating IGF1 expression on differentiation of osteoblasts under mechanical stimulation].

PURPOSE: To investigate the expression change of microRNA (miR) - 199a in MC3T3-E1 cells stimulated by mechanical stretch and its mechanism of osteogenic differentiation. METHODS: MC3T3-E1 cells cultured in vitro were loaded with 12% stretch for 0, 3, 6, 12 and 24 hours, alkaline phosphatase (ALP) activity was detected by ALP activity test kit, the expressions of osteocalcin (OCN), osteoblast specific transcription factor osterix (OSX), Runt related transcription factor 2 (Runx2) mRNA and miR-199a were detected by real-time fluorescence quantitative PCR. MC3T3-E1 cells were divided into control group, stretch group, stretch + miR-NC group and stretch + miR-199a group, and the expressions of miR-199a, OCN, OSX, Runx2 mRNA and protein and ALP activity were observed after 12% stretch and transfection of miR-199a. Alizarin red S (ARS) staining was used to observe calcium nodule formation ability. The target relationship between miR-199a and insulin like growth factor-1 (IGF1) was detected by double luciferase reporter gene assay; in addition, the effect of miR-199a mimic on IGF1 mRNA and protein expression was detected by real-time fluorescent quantitative PCR and Western blot. SPSS 24.0 software package was used to analyze the data. RESULTS: Compared with those at the time point of 0 h, ALP activity and expression level of OCN, OSX and Runx2 mRNA of MC3T3-E1 cells at 3, 6, 12 and 24 hours after mechanical stretch stimulation were significantly higher, while the expression level of miR-199a was significantly lower(P＜0.05), and the change was most significant at 12 h. Compared with those in the control group, the expression level of miR-199a was significantly lower in the stretch group, while ALP activity, the expression level of OCN, OSX and Runx2 mRNA and protein, calcium nodule formation level were significantly high in the stretch group(P＜0.05); there was no significant difference in the above indexes between the stretch group and stretch + miR-NC group(P＞0.05). Compared with stretch + miR-NC group, the expression level of miR-199a in stretch + miR-199a group was significantly higher; while ALP activity, OCN, OSX, Runx2 mRNA and protein expression level, calcium nodule formation level were significantly lower(P＜0.05). miR-199a could targetedly bind to IGF1, and the expression level of IGF1 mRNA and protein in MC3T3-E1 cells was significantly reduced by miR-199a mimic(P＜0.05). CONCLUSIONS: MiR-199a can inhibit the osteogenic differentiation of MC3T3-E1 cells induced by mechanical stretch stimulation, and its mechanism may be related to the targeted regulation of IGF1 expression.

Mesoporous hollow Fe3O4 nanoparticles regulate the behavior of neuro-associated cells through induction of macrophage polarization in an alternating magnetic field.

Magnetic iron oxide nanoparticles have shown great research value in the field of nerve regeneration because of their characteristics of satisfactory material properties and their ability to be stimulated by an external magnetic field to enhance the function of all aspects. Nevertheless, the impact of magnetic iron oxide nanoparticles on nerve regeneration regulated by macrophage polarization has not been well studied, and it is also not clear whether the introduction of the magnetic field has a further effect. Therefore, mesoporous hollow Fe3O4 nanoparticles (MHFPs) were synthesized. We selected an alternating magnetic field (AMF) because it may confer a stronger effect on MHFPs as compared to a static magnetic field, and then explored the field's ability to induce macrophage polarization. Furthermore, the effects of this regulation on other neuro-associated cells were also explored. Our results suggest that MHFPs can efficiently induce polarization of macrophages at the concentration of 40 µg mL-1, upregulate the expression of related genes and cytokines, and further promote the proliferation of neural stem cells and the subsequent migration of vascular endothelial cells. These effects were significantly enhanced after the application of an AMF. This work also showed that the internalization of particles is the starting point for polarization regulation.

Simultaneous detection of 93 anabolic androgenic steroids in dietary supplements using gas chromatography tandem mass spectrometry.

In recent years, anabolic androgenic steroids (AASs) have been frequently detected as undeclared ingredients in dietary supplements, where the adverse analytical findings (AAFs) were obtained from analysis of athletes' urine samples after ingestion. In our present study, a GC-MS/MS method for simultaneous detection of 93 anabolic steroids was developed. The chromatographic and mass spectrometric conditions were optimized, and selective reaction monitoring (SRM) mode was adopted to obtain the necessary sensitivity. The whole sample analysis process was completed within 23 min, and the limit of detection (LOD) was 0.5-4 ng.g-1 for solid samples and 0.1-0.8 ng.mL-1 for liquid samples. This method was verified according to World Anti-Doping Agency (WADA) regulations. In addition, the method was found to be specific, accurate. The developed method was then applied to a routine analysis of more than 300 liquid and solid dietary supplements, and one testosterone-positive sample was found. Three suspected drugs, (4-hydroxyandrostenedione, DHEA, and 6-Br androstenedione) were found in three dietary supplements obtained from the Internet through the pretreatment method of this study. This study provides a high-throughput method for screening and monitoring the ingredients of supplements and their subsequent harm to public health.

Enhanced proliferation and differentiation of neural stem cells by peptide-containing temperature-sensitive hydrogel scaffold.

Hydrogel has attracted great attention in the past few years as a widely used material for repairing central nerve damage. However, conventional hydrogel bio-scaffold, such as chitosan, gelatin, and sodium alginate, lack sufficient biological activity and have limited nerve repair capabilities. Therefore, to explore biologically active and intelligent hydrogel materials is particularly important and necessary for central nerve repair. Herein, we developed a temperature-sensitive hydrogel grafted with a bioactive peptide IKVAV (Ile-Lys-Val-Ala-Val, IKVAV). The hydrogel was prepared by copolymerization of N-propan-2-ylprop-2-enamide (NIPAM) and AC-PEG-IKVAV copolymers via reversible addition-fracture chain transfer (RAFT) polymerization, using polyethylene glycol (PEGDA) and N, N'-Methylenebisacrylamide (BISAM) as cross-linking agents. The prepared hydrogel scaffold demonstrates a series of excellent properties such as rapid (de)swelling performance, good biocompatibility, regular three-dimensional porous structure, and in particular good biological activity, which can guide cell fate and mediate neuron's differentiation. Therefore, the developed peptide hydrogel scaffold provides a new strategy for designing biomaterials that are widely used in tissue engineering for central nervous system injury.

Detection of Prostate Cancer Antigen 3 and Prostate Cancer Susceptibility Candidate in Non-DRE Urine Improves Diagnosis of Prostate Cancer in Chinese Population.

Although prostate biopsy is the gold standard for the diagnosis of prostate cancer, it also leads to high incidence of negative biopsies and the diagnosis of clinically low-risk prostate cancer and the subsequent overtreatment. It remains an unmet need to discover new biomarkers in order to defer the unnecessary biopsies in clinical practice. In this study, we described a new method, LBXexo score, to measure the urine exosomal PCA3/PRAC expression from non-DRE urine as a noninvasive diagnosis to improve the detection rate in Chinese population with a low serum PSA level. First-voided urine samples were collected to isolate exosomes, and exosomal RNAs of PCA3 and PRAC were measured by quantitative reverse transcription PCR. A significant increase in exoPCA3/PRAC was observed in both any-grade and high-grade prostate cancer groups when compared with the biopsy-negative group. Receiver-operating characteristic curve analyses showed that the LBXexo score significantly improved diagnostic performance in predicting biopsy results, with AUCs of 0.723 (p=0.017) and 0.736 (p=0.038) for any-grade and high-grade (GS ≥ 7) prostate cancer, respectively. For high-grade cancer, LBXexo had the negative and positive predictive values of 100% and 27.59%, respectively, and could potentially avoid unnecessary biopsy. This is the first report in Chinese population that demonstrates the predictive value of the exosomal expression of PCA3 and PRAC derived from non-DRE urine in predicting prostate biopsy outcomes. It could be used in clinical practice to make a better informed biopsy decision and avoid unnecessary biopsies in Chinese population.

Citric acid modification of a polymer exhibits antioxidant and anti-inflammatory properties in stem cells and tissues.

Biomaterials can be used as carriers of antioxidant or drug to the oxidative injury site of tissue and decrease intracellular oxidative stress levels, however, low dosage delivery or unstable molecular structure of antioxidant or drug limited the long-term sustained release. A chemically stable antioxidant molecule is essential to serve as antioxidant structure components of biomaterials that may provide the relatively high antioxidant content and persisting local antioxidant release with the degradation of materials. In this study, we used citric acid modified polyvinyl alcohol (PVA-C) as a model biomaterial to investigate the role of citric acid on the material stimulated antioxidant and anti-inflammatory effects. In cellular-based assays, PVA-C extracts showed a protective effects on bone marrow mesenchymal stem cells (BMSCs) under oxidative stress. It could enhance the antiapoptotic ability of stem cells by inhibiting reactive oxygen species. Further studies revealed that PVA-C extracts upregulated the nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) and superoxide dismutase [Mn] (SOD2). in vivo animal assays, PVA-C extracts showed significant inhibitory effects on the oxidative stress and inflammatory reaction which were induced by lipopolysaccharide (LPS). These findings suggest that the citric acid modified polymer can regulate the redox signaling of stem cells and tissues by the release of citric acid from materials, leading to enhanced oxidative stress-induced degenerative diseases and inflammatory diseases therapy.

In vitro and in vivo mechanism of hepatocellular carcinoma inhibition by ß-TCP nanoparticles.

Background: Studies have showed that nanoparticles have a certain anti-cancer activity and can inhibit many kinds of cancer cells. ß-tricalcium phosphate nanoparticles (nano-ß-TCP) displays better biodegradation, but the application and mechanism of nano-ß-TCP in anti-cancer activity are still not clear. Purpose: The objective of this study was to synthesize nano-ß-TCP and investigate its inhibitory properties and mechanism on hepatocellular carcinoma (HepG2) cells in vitro and in vivo. Methods: Nano-ß-TCP was synthesized using ethanol-water system and characterized. The effects of nano-ß-TCP on cell viability, cell uptake, intracellular oxidative stress (ROS), cell cycle and apoptosis were also investigated with HepG2 cells and human hepatocyte cells (L-02). Intratumoral injection of nano-ß-TCP was performed on the xenograft liver cancer model to explore the inhibitory effect and mechanism of nano-ß-TCP on liver tumors. Results: In vitro results revealed that nano-ß-TCP caused reduced cell viability of HepG2 cells in a time-and dose-dependent manner. Nano-ß-TCP was internalized through endocytosis and degraded in cells, resulting in obvious increase of the intracellular Ca2+ and PO4 3- ions. Nano-ß-TCP induced cancer cells to produce ROS and induced apoptosis of tumor cells by an apoptotic signaling pathways both in extrinsic and intrinsic pathway. In addition, nano-ß-TCP blocked cell cycle of HepG2 cells in G0/G1 phase and disturbed expression of some related cyclins. In vivo results showed that 40 mg/kg of nano-ß-TCP had no significant toxic side effects, but could effectively suppress hepatocellular carcinoma growth. Conclusion: These findings revealed the anticancer effect of nano-ß-TCP and also clarified the mechanism of its inhibitory effect on hepatocellular carcinoma.

Manipulating Mesenchymal Stem Cells Differentiation Under Sinusoidal Electromagnetic Fields Using Intracellular Superparamagnetic Nanoparticles.

In this study, hollow mesoporous ferrite nanoparticles (HMFNs) were prepared. It showed a spherical morphology with a diameter about 320 nm, with a negatively charged surface, and with a great superparamagnetic property. Negative charge attribute to the free -OH group of the HMFNs shell, which improved nanoparticles hydrophilic and biocompatibility. Superparamagnetic property could avoids particle agglomeration. The particles were shown to be internalized into the bone marrow mesenchymal stem cells (BMSCs) in vitro. We found that the intracellular HMFNs can improve the osteogenic differentiation of BMSCs in the presence of an electromagnetic fields. To determine the optimal intensity of the sinusoidal electromagnetic field (SEMF), the exposure levels of 50 Hz SEMF in the range of 0∼4 mTs (60 min/day) were utilized to investigate its effects on the proliferation and osteogenic differentiation of rat BMSCs. The result showed that the 1 mT and 2 mT SEMF stimulated the BMSCs proliferation significantly. The internalized HMFNs in conjunction with SEMF exposure enhanced the osteogenic differentiation, as evidenced by elevated alkaline phosphatase activity, calcium deposition, and the expression protein levels of the expression profile of osteopontin, osteocalcin and runt-related transcription factor 2. We believe that the electromagnetic fields can manipulate osteogenic differentiation of BMSCs using intracellular superparamagnetic nanoparticles.

A prediction model for blood-brain barrier permeation and analysis on its parameter biologically.

The objective of this paper is to build a reliable model based on the artificial neural network (ANN) for predicting the blood-brain barrier (BBB) permeability and reveal the effects of the molecular descriptor on the BBB permeability. Eight descriptors including high-affinity P-gp substrate probability and plasma protein binding ratio are selected to develop the model. The three layers feedforward neural network (8-5-1) is employed for the prediction of logBB. By analyzing the experimental results, polar surface area (PSA) seems to be the most important factor for BBB permeability. Different from traditional view, the Abraham's hydrogen-bond basicity (HBB) can make a positive contribution to logBB in rational range. The experimental results show that the ANN based model with eight selected descriptors as inputs can achieve good performance for logBB prediction, and the results of sensitivity analysis can be confirmed by the present biological and chemical research.