scholarly journals Antibiotic loaded β-tricalcium phosphate/calcium sulfate for antimicrobial potency, prevention and killing efficacy of Pseudomonas aeruginosa and Staphylococcus aureus biofilms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nan Jiang ◽  
Devendra H. Dusane ◽  
Jacob R. Brooks ◽  
Craig P. Delury ◽  
Sean S. Aiken ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Calcium Sulfate ◽  
Bone Graft Substitute ◽  
In Vitro Assays ◽  
In Vivo Experiments ◽  
Orthopaedic Infections ◽  
Clinical Investigations ◽  
Antimicrobial Potency

AbstractThis study investigated the efficacy of a biphasic synthetic β-tricalcium phosphate/calcium sulfate (β-TCP/CS) bone graft substitute for compatibility with vancomycin (V) in combination with tobramycin (T) or gentamicin (G) evidenced by the duration of potency and the prevention and killing efficacies of P. aeruginosa (PAO1) and S. aureus (SAP231) biofilms in in vitro assays. Antibiotic loaded β-TCP/CS beads were compared with antibiotic loaded beads formed from a well characterized synthetic calcium sulfate (CS) bone void filler. β-TCP/CS antibiotic loaded showed antimicrobial potency against PAO1 in a repeated Kirby-Bauer like zone of inhibition assay for 6 days compared to 8 days for CS. However, both bead types showed potency against SAP231 for 40 days. Both formulations loaded with V + T completely prevented biofilm formation (CFU below detection limits) for the 3 days of the experiment with daily fresh inoculum challenges (P < 0.001). In addition, both antibiotic loaded materials and antibiotic combinations significantly reduced the bioburden of pre-grown biofilms by between 3 and 5 logs (P < 0.001) with V + G performing slightly better against PAO1 than V + T. Our data, combined with previous data on osteogenesis suggest that antibiotic loaded β-TCP/CS may have potential to stimulate osteogenesis through acting as a scaffold as well as simultaneously protecting against biofilm infection. Future in vivo experiments and clinical investigations are warranted to more comprehensively evaluate the use of β-TCP/CS in the management of orthopaedic infections.

Potential Anti-inflammatory Sesquiterpene Lactones from Eupatorium lindleyanum

Planta Medica ◽  
2017 ◽  
Vol 84 (02) ◽  
pp. 123-128 ◽  
Author(s):  
Fang Wang ◽  
Huanhuan Zhong ◽  
Shiqi Fang ◽  
Yunfeng Zheng ◽  
Cunyu Li ◽  
...  
Keyword(s):  
Sesquiterpene Lactones ◽  
Folk Medicine ◽  
2D Nmr ◽  
In Vitro Assays ◽  
Raw 264.7 Cells ◽  
Therapeutic Effects ◽  
In Vivo Experiments ◽  
Anti Inflammatory

Abstract Eupatorium lindleyanum has traditionally been used as folk medicine in Asian countries for its therapeutic effects on tracheitis and tonsillitis. Investigation of the anti-inflammatory active constituents from E. lindleyanum led to the isolation of two novel sesquiterpene lactones, named eupalinolide L (1) and eupalinolide M (2), and seven known sesquiterpene lactones (3–9). The structures and configurations of the new compounds were determined on the basis of spectroscopic analysis, especially 2D NMR techniques. In vivo experiments showed that the sesquiterpenes fraction significantly reduced mouse ear edema induced by xylene (18.6%, p < 0.05). In in vitro assays, compounds 1–9 showed excellent anti-inflammatory activities, as they lowered TNF-α and IL-6 levels in lipopolysaccharide-stimulated murine macrophage RAW 264.7 cells (p < 0.001). The above results suggest that the sesquiterpene lactones from E. lindleyanum can be developed as novel potential natural anti-inflammatory agents.

scholarly journals Agent-based modeling of cancer stem cell driven solid tumor growth

2015 ◽  
Author(s):  
Jan T Poleszczuk ◽  
Paul Macklin ◽  
Heiko Enderling
Keyword(s):  
Stem Cell ◽  
Cancer Stem Cell ◽  
Tumor Growth ◽  
Population Level ◽  
In Vitro Assays ◽  
Agent Based ◽  
In Vivo Experiments ◽  
Behavioral Rules

Computational modeling of tumor growth has become an invaluable tool to simulate complex cell-cell interactions and emerging population-level dynamics. Agent-based models are commonly used to describe the behavior and interaction of individual cells in different environments. Behavioral rules can be informed and calibrated by in vitro assays, and emerging population-level dynamics may be validated with both in vitro and in vivo experiments. Here, we describe the design and implementation of a lattice-based agent-based model of cancer stem cell driven tumor growth.

scholarly journals Silicate/zinc-substituted strontium apatite coating improves the osteoinductive properties of β-tricalcium phosphate bone graft substitute

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hironori Sugimoto ◽  
Yusuke Inagaki ◽  
Akira Furukawa ◽  
Tsutomu Kira ◽  
Sachiko Kawasaki ◽  
...  
Keyword(s):  
Bone Graft ◽  
Mrna Expression ◽  
Tricalcium Phosphate ◽  
Bone Graft Substitute ◽  
Allogeneic Bone ◽  
Qrt Pcr ◽  
Alp Activity ◽  
Apatite Coating

Abstract Background β-Tricalcium phosphate (β-TCP) is a popular synthetic bone graft substitute with excellent osteoconductive properties and bioabsorbability. However, its osteoinductive properties are inferior to those of autologous or allogeneic bone. Trace elements such as strontium (Sr), silica (Si), and zinc (Zn) have been reported to promote osteogenesis in materials. In this study, we aimed to determine whether a Si/Zn-substituted Sr apatite coating of β-TCP could enhance osteoinductive properties. Methods The apatite-coated β-TCP disks were prepared using nanoparticle suspensions of silicate-substituted Sr apatite (SrSiP) or silicate- and Zn-co-substituted Sr apatite (SrZnSiP). Bone marrow mesenchymal cells (BMSCs) from rat femur were cultured and subsequently seeded at a density of 1.0 × 106/cm2 onto apatite-coated and non-coated β-TCP disks. In vitro, the β-TCP disks were then placed in osteogenic medium, and lactate dehydrogenase (LDH) activity was measured from supernatants after culture for 2 days. Additionally, after culture for 14 days, the mRNA expression of genes encoding osteocalcin (OC), alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP-2), and vascular endothelial growth factor (VEGF) was evaluated by qRT-PCR. In vivo, the β-TCP disks were transplanted subcutaneously into rats that were sacrificed after 4 weeks. Then, the harvested disks were evaluated biochemically (ALP activity, OC content, mRNA expression of OC, ALP, BMP-2, and VEGF measured by qRT-PCR), radiologically, and histologically. Results Significantly higher mRNA expression of almost all evaluated osteogenic and angiogenic genes was observed in the SrZnSiP and SrSiP groups than in the non-coated group, with no significant cytotoxicity elicited by the apatite coating in vitro. Moreover, in vivo, the SrZnSiP and SrSiP groups showed significantly higher osteogenic and angiogenic gene expression and higher ALP activity and OC content than the non-coated group (P < 0.05). Radiological and histopathological findings revealed abundant bone formation in the apatite-coated group. Conclusions Our findings indicate that apatite coating of β-TCP improves osteoinductive properties without inducing significant cytotoxicity.

Host Defence Cryptides from Human Apolipoproteins: Applications in Medicinal Chemistry

2020 ◽  
Vol 20 (14) ◽  
pp. 1324-1337 ◽  
Author(s):  
Rosa Gaglione ◽  
Elio Pizzo ◽  
Eugenio Notomista ◽  
Cesar de la Fuente-Nunez ◽  
Angela Arciello
Keyword(s):  
Bioactive Peptides ◽  
Biological Activities ◽  
Host Defence ◽  
New Drugs ◽  
In Vitro Assays ◽  
Protein Cleavage ◽  
Anticancer Activities ◽  
In Vivo Experiments

Several eukaryotic proteins with defined physiological roles may act as precursors of cryptic bioactive peptides released upon protein cleavage by the host and/or bacterial proteases. Based on this, the term “cryptome” has been used to define the unique portion of the proteome encompassing proteins with the ability to generate bioactive peptides (cryptides) and proteins (crypteins) upon proteolytic cleavage. Hence, the cryptome represents a source of peptides with potential pharmacological interest. Among eukaryotic precursor proteins, human apolipoproteins play an important role, since promising bioactive peptides have been identified and characterized from apolipoproteins E, B, and A-I sequences. Human apolipoproteins derived peptides have been shown to exhibit antibacterial, anti-biofilm, antiviral, anti-inflammatory, anti-atherogenic, antioxidant, or anticancer activities in in vitro assays and, in some cases, also in in vivo experiments on animal models. The most interesting Host Defence Peptides (HDPs) identified thus far in human apolipoproteins are described here with a focus on their biological activities applicable to biomedicine. Altogether, reported evidence clearly indicates that cryptic peptides represent promising templates for the generation of new drugs and therapeutics against infectious diseases.

Totally Biodegradable and Osteoconductive Composite Material Consisting of Polyhydroxybutyrate and Tricalcium Phosphate for Bone Tissue Repair

2008 ◽  
Vol 47-50 ◽  
pp. 1395-1398
Author(s):  
Ya Liu ◽  
Min Wang
Keyword(s):  
Composite Material ◽  
Bone Tissue ◽  
Tricalcium Phosphate ◽  
Tissue Repair ◽  
Scanning Calorimetry ◽  
Electron Microscopic ◽  
In Vivo Experiments ◽  
Composite Production

Totally biodegradable and osteoconductive composite material consisting of polyhydroxybutyrate (PHB) and β-tricalcium phosphate (β-TCP) was manufactured for bone tissue repair. The composite production process was optimized with the help of differential scanning calorimetry (DSC) analyses. Thermogravimetric analyses (TGA) indicated that intended compositions for TCP/PHB composite could be achieved through this manufacturing route. Scanning electron microscopic (SEM) examinations revealed that TCP/PHB composite containing up to 40 vol.% of β-TCP had satisfactory distribution of micron-sized TCP particles in the composite. The good-quality composite will be further investigated in in vitro and in vivo experiments.

scholarly journals Bacillus-based products for management of kiwifruit bacterial canker

2021 ◽  
Vol 60 (2) ◽  
pp. 215-228
Author(s):  
Enrico BIONDI ◽  
Lorenzo GALLIPOLI ◽  
Angelo MAZZAGLIA ◽  
Set Perez FUENTEALBA ◽  
Nemanja KUZMANOVIĆ ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Control Strategies ◽  
In Vitro Assays ◽  
Bacterial Canker ◽  
Streptomycin Sulphate ◽  
In Vivo Experiments ◽  
Ca 50 ◽  
Pathogen Populations

Pseudomonas syringae pv. actinidiae is an important pathogen of kiwifruit (Actinidia deliciosa), and bacterial canker of this host is managed by monitoring and chemical control strategies. The efficacy of the bio-pesticides Amylo-X® (based on Bacillus amyloliquefaciens subsp. plantarum strain D747) and Serenade Max® (strain QST713 of B. subtilis) was evaluated by in vitro and in vivo experiments. Both antagonists inhibited different biovars of the pathogen in in vitro assays; QST713 was more efficient than D747. The two Bacillus strains also colonized A. deliciosa flowers (c. 105-7 cfu per flower) up to 96 h after inoculation. D747 persisted on leaves (c. 104-6 cfu cm-2) up to 4 weeks after inoculation, during 2 years in Emilia Romagna and Latium regions of Italy. On flowers, the antagonists reduced pathogen populations, compared to untreated (control) flowers. On A. deliciosa and A. chinensis plants under controlled conditions, Amylo-X® reduced severity of bacterial canker, providing ca. 50% relative protection on A. deliciosa and 70% on A. chinensis. Serenade Max® was less effective, giving 0% relative protection on A. deliciosa and 40% on A. chinensis. In a field trial, on A. deliciosa plants, Amylo-X® reduced the severity of bacterial canker on leaves, providing ca. 40% relative protection. The sensitivity of both antagonistic strains to streptomycin sulphate was confirmed by testing the most used concentration where antibiotics are approved for management of bacterial pathogens.

scholarly journals Silicate/zinc-substituted strontium apatite coating improves the osteoinductive properties of β-tricalcium phosphate bone graft substitute

2021 ◽  
Author(s):  
Hironori Sugimoto ◽  
Yusuke Inagaki ◽  
Akira Furukawa ◽  
Tsutomu Kira ◽  
Sachiko Kawasaki ◽  
...  
Keyword(s):  
Bone Graft ◽  
Mrna Expression ◽  
Tricalcium Phosphate ◽  
Bone Graft Substitute ◽  
Allogeneic Bone ◽  
Qrt Pcr ◽  
Alp Activity ◽  
Apatite Coating

Abstract Background: β-Tricalcium phosphate (β-TCP) is a popular synthetic bone graft substitute with excellent osteoconductive properties and bioabsorbability. However, its osteoinductive properties are inferior to those of autologous or allogeneic bone. Trace elements such as strontium (Sr), silica (Si), and zinc (Zn) have been reported to promote osteogenesis in materials. In this study, we aimed to determine whether a Si/Zn-substituted Sr apatite coating of β-TCP could enhance osteoinductive properties.Methods: The apatite-coated β-TCP disks were prepared using nanoparticle suspensions of silicate-substituted Sr apatite (SrSiP) or silicate- and Zn-co-substituted Sr apatite (SrZnSiP).Bone marrow mesenchymal cells (BMSCs) from rat femur were cultured and subsequently seeded at a density of 1.0 × 106/cm2 onto apatite-coated and non-coated β-TCP disks.In vitro, the β-TCP disks were then placed in osteogenic medium, and lactate dehydrogenase (LDH) activity was measured from supernatants after culture for 2 days. Additionally, after culture for 14 days, the mRNA expression of genes encoding osteocalcin (OC), alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP-2), and vascular endothelial growth factor (VEGF) was evaluated by qRT-PCR. In vivo, the β-TCP disks were transplanted subcutaneously into rats that were sacrificed after 4 weeks. Then, the harvested disks were evaluated biochemically (ALP activity, OC content, mRNA expression of OC, ALP, BMP-2, and VEGF measured by qRT-PCR), radiologically, and histologically.Results: Significantly higher mRNA expression of almost all evaluated osteogenic and angiogenic genes was observed in the SrZnSiP and SrSiP groups than in the non-coated group, with no significant cytotoxicity elicited by the apatite coating in vitro. Moreover, in vivo, the SrZnSiP and SrSiP groups showed significantly higher osteogenic and angiogenic gene expression and higher ALP activity and OC content than the non-coated group (P < 0.05). Radiological and histopathological findings revealed abundant bone formation in the apatite-coated group.Conclusions: Our findings indicate that apatite coating of β-TCP improves osteoinductive properties without inducing significant cytotoxicity.

scholarly journals Ca2+ Flux: Searching for a Role in Efferocytosis of Apoptotic Cells in Atherosclerosis

2019 ◽  
Vol 8 (12) ◽  
pp. 2047 ◽  
Author(s):  
Amir Tajbakhsh ◽  
Petri T. Kovanen ◽  
Mahdi Rezaee ◽  
Maciej Banach ◽  
Amirhossein Sahebkar
Keyword(s):  
Actin Polymerization ◽  
Foam Cell ◽  
Foam Cells ◽  
In Vivo Experiments ◽  
Clinical Complications ◽  
Clinical Investigations ◽  
Atherosclerotic Cardiovascular Diseases

In atherosclerosis, macrophages in the arterial wall ingest plasma lipoprotein-derived lipids and become lipid-filled foam cells with a limited lifespan. Thus, efficient removal of apoptotic foam cells by efferocytic macrophages is vital to preventing the dying foam cells from forming a large necrotic lipid core, which, otherwise, would render the atherosclerotic plaque vulnerable to rupture and would cause clinical complications. Ca2+ plays a role in macrophage migration, survival, and foam cell generation. Importantly, in efferocytic macrophages, Ca2+ induces actin polymerization, thereby promoting the formation of a phagocytic cup necessary for efferocytosis. Moreover, in the efferocytic macrophages, Ca2+ enhances the secretion of anti-inflammatory cytokines. Various Ca2+ antagonists have been seminal for the demonstration of the role of Ca2+ in the multiple steps of efferocytosis by macrophages. Moreover, in vitro and in vivo experiments and clinical investigations have revealed the capability of Ca2+ antagonists in attenuating the development of atherosclerotic plaques by interfering with the deposition of lipids in macrophages and by reducing plaque calcification. However, the regulation of cellular Ca2+ fluxes in the processes of efferocytic clearance of apoptotic foam cells and in the extracellular calcification in atherosclerosis remains unknown. Here, we attempted to unravel the molecular links between Ca2+ and efferocytosis in atherosclerosis and to evaluate cellular Ca2+ fluxes as potential treatment targets in atherosclerotic cardiovascular diseases.

scholarly journals Chemoattraction of Neoplastic Glial Cells with CXCL10, CCL2 and CCL11 as a Paradigm for a Promising Therapeutic Approach for Primary Brain Tumors

2021 ◽  
Vol 22 (22) ◽  
pp. 12150
Author(s):  
Laurence Déry ◽  
Gabriel Charest ◽  
Brigitte Guérin ◽  
Mohsen Akbari ◽  
David Fortin
Keyword(s):  
Brain Tumors ◽  
Tumor Cells ◽  
Therapeutic Approach ◽  
Brain Parenchyma ◽  
In Vitro Assays ◽  
Primary Brain Tumors ◽  
In Vivo Experiments ◽  
Promising Therapeutic Approach

Chemoattraction is a normal and essential process, but it can also be involved in tumorigenesis. This phenomenon plays a key role in glioblastoma (GBM). The GBM tumor cells are extremely difficult to eradicate, due to their strong capacity to migrate into the brain parenchyma. Consequently, a complete resection of the tumor is rarely a possibility, and recurrence is inevitable. To overcome this problem, we proposed to exploit this behavior by using three chemoattractants: CXCL10, CCL2 and CCL11, released by a biodegradable hydrogel (GlioGel) to produce a migration of tumor cells toward a therapeutic trap. To investigate this hypothesis, the agarose drop assay was used to test the chemoattraction capacity of these three chemokines on murine F98 and human U87MG cell lines. We then studied the potency of this approach in vivo in the well-established syngeneic F98-Fischer glioma-bearing rat model using GlioGel containing different mixtures of the chemoattractants. In vitro assays resulted in an invasive cell rate 2-fold higher when chemokines were present in the environment. In vivo experiments demonstrated the capacity of these specific chemoattractants to strongly attract neoplastic glioblastoma cells. The use of this strong locomotion ability to our end is a promising avenue in the establishment of a new therapeutic approach in the treatment of primary brain tumors.

scholarly journals PIAS1 alleviates diabetic peripheral neuropathy through SUMOlation of PPAR-γ and miR-124-induced downregulation of EZH2/STAT3

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zixin Hou ◽  
Ji Chen ◽  
Huan Yang ◽  
Xiaoling Hu ◽  
Fengrui Yang
Keyword(s):  
Peripheral Neuropathy ◽  
Schwann Cells ◽  
Diabetic Peripheral Neuropathy ◽  
Nerve Tissue ◽  
In Vitro Assays ◽  
In Vivo Experiments ◽  
Ppar Γ ◽  
Gene Reporter Assay

AbstractDiabetic peripheral neuropathy (DPN) is a frequently occurring chronic complication of diabetes. In this study, we aim to explore the regulatory mechanism of protein inhibitor of activated STAT1 (PIAS1) in DPN in terms of autophagy and apoptosis of Schwann cells. The SUMOlation of PPAR-γ by PIAS1 was examined, and ChIP was performed to verify the binding of PPAR-γ to miR-124 promoter region. Dual-luciferase gene reporter assay was used to validate the binding affinity between miR-124 and EZH2/STAT3. Following loss‐ and gain‐of-function experiments, in vitro assays in high glucose-treated Schwann cells (SC4) and in vivo assays in db/db and ob/ob mice were performed to detect the effects of PIAS1 on autophagy and apoptosis of Schwann cells as well as symptoms of DPN by regulating the PPAR-γ-miR-124-EZH2/STAT3. The expression of PIAS1, PPAR-γ, and miR-124 was downregulated in the sciatic nerve tissue of diabetic mice. PIAS1 enhanced the expression of PPAR-γ through direct binding and SUMOlation of PPAR-γ. PPAR-γ enhanced the expression of miR-124 by enhancing the promoter activity of miR-124. Furthermore, miR-124 targeted and inversely modulated EZH2 and STAT3, promoting the autophagy of Schwann cells and inhibiting their apoptosis. In vivo experiments further substantiated that PIAS1 could promote the autophagy and inhibit the apoptosis of Schwann cells through the PPAR-γ-miR-124-EZH2/STAT3 axis. In conclusion, PIAS1 promoted SUMOlation of PPAR-γ to stabilize PPAR-γ expression, which upregulated miR-124 to inactivate EZH2/STAT3, thereby inhibiting apoptosis and promoting autophagy of Schwann cells to suppress the development of DPN.

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