3D Bioprinted Tissue-Engineered Bone with Enhanced Mechanical Strength and Bioactivities: Accelerating Bone Defect Repair through Sequential Immunomodulatory Properties.

In this study, a new-generation tissue-engineered bone capable of temporally regulating the immune response, balancing proinflammatory and anti-inflammatory activities, and facilitating bone regeneration and repair to address the challenges of delayed healing and nonunion in large-sized bone defects, is innovatively developed. Using the innovative techniques including multiphysics-assisted combined decellularization, side-chain biochemical modification, and sterile freeze-drying, a novel photocurable extracellular matrix hydrogel, methacrylated bone-derived decellularized extracellular matrix (bdECM-MA), is synthesized. After incorporating the bdECM-MA with silicon-substituted calcium phosphate and bone marrow mesenchymal stem cells, the tissue-engineered bone is fabricated through digital light processing 3D bioprinting. This study provides in vitro confirmation that the engineered bone maintains high cellular viability while achieving MPa-level mechanical strength. Moreover, this engineered bone exhibits excellent osteogenesis, angiogenesis, and immunomodulatory functions. One of the molecular mechanisms of the immunomodulatory function involves the inhibition of the p38-MAPK pathway. A pioneering in vivo discovery is that the natural biomaterial-based tissue-engineered bone demonstrates sequential immunomodulatory properties that activate proinflammatory and anti-inflammatory responses in succession, significantly accelerating the repair of bone defects. This study provides a new research basis and an effective method for developing autogenous bone substitute materials and treating large-sized bone defects.

The Masquelet induced membrane technique with PRP-FG-nHA/PA66 scaffold can heal a rat large femoral bone defect.

BACKGROUND: Masquelet membrane induction technology is one of the treatment strategies for large bone defect (LBD). However, the angiogenesis ability of induced membrane decreases with time and autologous bone grafting is associated with donor site morbidity. This study investigates if the PRP-FG-nHA/PA66 scaffold can be used as a spacer instead of PMMA to improve the angiogenesis ability of induced membrane and reduce the amount of autologous bone graft. METHODS: Platelet rich plasma (PRP) was prepared and PRP-FG-nHA/PA66 scaffold was synthesized and observed. The sustained release of VEGFA and porosity of the scaffold were analyzed. We established a femur LBD model in male SD rats. 55 rats were randomly divided into four groups depending on the spacer filled in the defect area. "Defect only" group (n = 10), "PMMA" group (n = 15), "PRP-nHA/PA66" group (n = 15) and "PRP-FG-nHA/PA66" group (n = 15 ). At 6 weeks, the spacers were removed and the defects were grafted. The induced membrane and bone were collected and stained. The bone formation was detected by micro-CT and the callus union was scored on a three point system. RESULTS: The PRP-FG-nHA/PA66 scaffold was porosity and could maintain a high concentration of VEGFA after 30 days of preparation. The induced membrane in PRP-FG-nHA/PA66 group was thinner than PMMA, but the vessel density was higher.The weight of autogenous bone grafted in PRP-FG-nHA/PA66 group was significantly smaller than that of PMMA group. In PRP-FG-nHA/PA66 group, the bone defect was morphologically repaired. CONCLUSION: The study showed that PRP-FG-nHA/PA66 scaffold can significantly reduce the amount of autologous bone graft, and can achieve similar bone defect repair effect as PMMA. Our findings provide some reference and theoretical support for the treatment of large segmental bone defects in humans.

A Hybrid Heuristic-Exact Optimization for Large-Scale Home Health Care Problem.

During the COVID-19 pandemic, numerous people experiencing illness or senescence choose to receive home health care (HHC) services. However, a rapid increase in patients makes it a challenge to reasonably allocate nurses to provide HHC services under the condition of a paucity of nurse resources and patient time window constraints. To solve the large-scale HHC problem, a hybrid heuristic-exact optimization algorithm is proposed with three novel contributions. Firstly, a framework of hybrid heuristic-exact optimization is designed to solve the large-scale problem where a reasonable solution is difficult to obtain under constraints. Secondly, a multi-objective mixed-integer linear programming modelization is formulated to get a more diverse nurse assignment. Finally, an improved branch and bound algorithm is proposed to speed up computation for the large-scale problem. Computational results on different HHC instances from 25 to 1000 patients demonstrate that the proposed algorithm can optimize the HHC problem with more than 100 patients and can provide various assignments for different numbers of nurses, which the common algorithm cannot optimize.

The Combination of Platelet Rich Plasma Gel, Human Umbilical Mesenchymal Stem Cells and Nanohydroxyapatite/polyamide 66 Promotes Angiogenesis and Bone Regeneration in Large Bone Defect.

BACKGROUND: In the present study, a novel tissue engineering bone graft including platelet rich plasma gel (PRP gel), human umbilical mesenchymal stem cells (HUMSCs) and nanohydroxyapatite/polyamide 66 (nHA-PA66) was constructed. We explored whether the composite scaffolds could enhance the angiogenesis and bone repair capacity in rat femoral large bone defect (LBD). This study aimed to provide evidence for the clinical application of the composite scaffold in LBD treatment. METHODS: PRP was prepared, the platelets and growth factors were measured. HUMSCs were isolated and identified. the osteogenic capacity of PRP in vitro was measured. Then HUMSCs-PRP-gel/nHA-PA66 composite scaffolds were synthesized and observed. The proliferation and osteogenesis differentiation of HUMSCs on the composite scaffold was measured. The angiogenic capacity of PRP in vitro was measured by capillary-like tube formation assay. Finally, the angiogenesis and bone repair capacity of the composite scaffolds was measured in rat LBD. RESULTS: PRP contained high level of platelets and growth factors after activation, and promoted osteogenic and angiogenic differentiation in vitro. The HUMSCs-PRP-gel/nHA-PA66 composite scaffold was porosity and promoted the proliferation and osteogenesis differentiation of HUMSCs. At 12th weeks, more micro-vessels and new bone were formed around the composite scaffolds compared with other groups, the defect was almost repaired. CONCLUSION: Our study for the first time identified that the combination of PRP gel, HUMSCs and nHA-PA66 scaffold could significantly promote angiogenesis and bone regeneration in rat LBD, which may have implications for its further application in clinical LBD treatment.

Silicon-substituted calcium phosphate promotes osteogenic-angiogenic coupling by activating the TLR4/PI3K/AKT signaling axis.

Silicon-substituted calcium phosphate (Si-CaP) is a promising bioactive material for bone tissue engineering. The mechanism of Si-CaP regulates osteogenic-angiogenic coupling during bone regeneration has not been fully elucidated. In this study, we screened the targets of Si-CaP and osteogenic-angiogenic coupling. 83 common genes were regarded as key targets for Si-CaP regulation of the osteogenic-angiogenic coupling. Then, we performed protein-protein interaction analysis, GO and KEGG enrichment analysis of these 83 targets to further predict their molecular mechanism. Our results showed that Si-CaP treatment could regulate the osteogenic-angiogenic coupling by up-regulating the expression of Toll-like receptor 4 (TLR4), and the phosphorylation of AKT which in turn activating the PI3K/AKT signaling pathway, promoting the expression of RUNX2, OPN, VEGF. In addition, we also found that TLR4 siRNA treatment could block the PI3K/AKT signaling pathway, while inhibiting the promoting effect of Si-CaP. However, although LY294002 can achieve the same inhibitory effect as TLR4 siRNA by blocking the PI3K/AKT signaling pathway, it could not affect the expression of TLR4. This indicates that TLR4 is an upstream activator of PI3K/AKT signaling pathway. These results are highly consistent with the prediction of bioinformatics. In conclusion, we have elucidated the role of TLR4/PI3K/AKT signaling axis in Si-CaP mediated osteogenic-angiogenic coupling for the first time. This study provides new data onto the regulatory role and molecular mechanism of Si-CaP in the process of osteogenic-angiogenic coupling, which strongly supports its wide application for bone tissue engineering.

The potential mechanism of Fructus Ligustri Lucidi promoting osteogenetic differentiation of bone marrow mesenchymal stem cells based on network pharmacology, molecular docking and experimental identification.

Recent studies have shown that the differentiation of bone marrow mesenchymal stem cells (BMSCs) into osteogenic lineages can promotes bone formation and maintains bone homeostasis, which has become a promising therapeutic strategy for skeletal diseases such as osteoporosis. Fructus Ligustri Lucidi (FLL) has been widely used for the treatment of osteoporosis and other orthopedic diseases for thousands of years. However, whether FLL plays an anti-osteoporosis role in promoting the osteogenic differentiation of BMSCs, as well as its active components, targets, and specific molecular mechanisms, has not been fully elucidated. First, we obtained 13 active ingredients of FLL from the Traditional Chinese Medicine Systems Pharmacology (TCSMP) database, and four active ingredients without any target were excluded. Subsequently, 102 common drug-disease targets were subjected to protein-protein interaction (PPI) analysis, Gene Oncology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The results of the three analyses were highly consistent, indicating that FLL promoted the osteogenic differentiation of BMSCs by activating the PI3K/AKT signaling pathway. Finally, we validated previous predictions using in vitro experiments, such as alkaline phosphatase (ALP) staining, alizarin red staining (ARS), and western blot analysis of osteogenic-related proteins. The organic combination of network pharmacological predictions with in vitro experimental validation comprehensively confirmed the reliability of FLL in promoting osteogenic differentiation of BMSCs. This study provides a strong theoretical support for the specific molecular mechanism and clinical application of FLL in the treatment of bone formation deficiency.

Simultaneous determination of actinides and 90Sr in large-size soil and sediment samples.

A simultaneous analytical method for sequential separation and determination of actinides and 90Sr in large-size environmental samples has been developed. In this method, successive co-precipitation steps were firstly conducted to remove matrix elements, then sequential column separation method was applied for simultaneous separation and purification of actinides and 90Sr/90Y. By using vacuum box technology, the total analytical time was minimized and batch processing allowed analyzing 12 samples in four days. The activity of 90Sr was obtained immediately by measuring its daughter radionuclide (90Y) with triple-to-double coincidence ratio (TDCR) Cherenkov counting, while the concentrations of Pu isotopes and 241Am could be measured by alpha spectrometry and mass spectrometric techniques. The overall recoveries of Pu, Am, Sr and Y were higher than 70% for the entire procedure, while the recovery ratios of Sr/Y were between 0.95 and 1.04 before chromatographic separation. The developed method was verified using 20 g and 50 g of environmental soil samples spiked with certified reference materials IAEA-384 or IAEA-385 and standard solution of 90Sr/90Y, and good agreement between the expected values and measured results has been achieved.

Therapeutic effects of Panax notoginseng saponins in rheumatoid arthritis: network pharmacology and experimental validation.

Panax notoginseng saponins (PNS) have been reported to have good anti-inflammatory effects. However, the anti-inflammatory effect mechanism in rheumatoid arthritis (RA) remains unknown. The focus of this research was to investigate the molecular mechanism of PNS in the treatment of RA. The primary active components of PNS were tested utilizing the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and Analysis Platform based on oral bioavailability and drug-likeness. The target databases for knee osteoarthritis were created using GeneCards and Online Mendelian Inheritance in Man (OMIM). The visual interactive network structure 'active component - action target - illness' was created using Cytoscape software. A protein interaction network was built, and associated protein interactions were analyzed using the STRING database. The key targets were analyzed using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) biological process enrichment analyses. The effects of PNS on cell growth were studied in human umbilical vein endothelial cells (HUVECs) treated with various doses of PNS, and the optimum concentration of PNS was identified. PNS was studied for its implication on angiogenesis and migration. The active components of PNS had 114 common targets, including cell metabolism and apoptosis, according to the network analysis. The therapeutic effects of the PNS components were suggested to be mediated through apoptotic and cytokine signaling pathways. In vitro, PNS therapy boosted HUVEC proliferation. Wound healing, Boyden chamber and tube formation tests suggested that PNS may increase HUVEC activity and capillary-like tube branching. This study clarified that for the treatment of RA, PNS has multisystem, multicomponent, and multitargeted properties.

Inflammatory Response, a Key Pathophysiological Mechanism of Obesity-Induced Depression.

In recent years, with the acceleration of life rhythm and the increase of social competition, the incidence of obesity and depression has been increasing, which has seriously affected the quality of life and health of people. Obesity and depression, two seemingly unrelated physical and psychological diseases, in fact, are closely related: obese people are more likely to have depression than nonobese ones. We have reviewed and analyzed the relevant research literature and found that the inflammatory response plays a key role in obesity-induced depression. This article will discuss in detail the inflammatory mechanisms by which obesity induces depression.