Poly-ϵ-caprolactone scaffold as staple-line reinforcement of rectal anastomosis: an experimental piglet study.

PURPOSE: Rectal anastomoses have a persisting high incidence of anastomotic leakage. This study aimed to assess whether the use of a poly-ϵ-caprolactone (PCL) scaffold as reinforcement of a circular stapled rectal anastomosis could increase tensile strength and improve healing compared to a control in a piglet model. METHOD: Twenty weaned female piglets received a stapled rectal anastomosis and were randomised to either reinforcement with PCL scaffold (intervention) or no reinforcement (control). On postoperative day five the anastomosis was subjected to a tensile strength test followed by a histological examination to evaluate the wound healing according to the Verhofstad scoring. RESULTS: The tensile strength test showed no significant difference between the two groups, but histological evaluation revealed significant impaired wound healing in the intervention group. CONCLUSION: The incorporation of a PCL scaffold into a circular stapled rectal anastomosis did not increase anastomotic tensile strength in piglets and indicated an impaired histologically assessed wound healing.

Extracting lignin from sugarcane bagasse for methylene blue and hexavalent chromium adsorption in textile wastewater: a facile, green, and sustainable approach.

This study presents the process of extracting lignin from sugarcane bagasse collected in the Mekong Delta, Vietnam by the alkali method. NaOH has been used as an effective, environmentally friendly chemical to enhance the extraction process. The obtained lignin was applied for methylene blue (MB) and hexavalent chromium (Cr(vi)) removal. Factors influencing lignin extraction and adsorption processes of MB and Cr(vi) were investigated, showcasing the sustainable reusability of lignin extracted from sugarcane bagasse. Lignin characterization was also carried out by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) techniques. The results showed that the extracted lignin content reached 38.61% under optimal conditions (NaOH concentration of 10%, reaction temperature of 90 °C and reaction time of 90 min). The adsorption efficiency and capacity of lignin reached 90.90% and 9.09 mg g-1 for MB and 80.10% and 28.04 mg g-1 for Cr(vi), respectively, under optimum adsorption conditions (pH, adsorption time, initial methylene blue concentration, and used lignin content). The adsorption process obeyed Langmuir adsorption and was principally physical adsorption. These findings prove sugarcane bagasse based lignin as a cheap and efficient adsorbent for MB and Cr(vi) removal, which contributes to the utilization of the abundant agricultural by-product for wastewater treatment.

Rational design of novel diaryl ether-linked benzimidazole derivatives as potent and selective BACE1 inhibitors.

Due to the large size and high flexibility of the catalytic active site of BACE1 enzyme, the development of nonpeptide inhibitors with optimal pharmacological properties is still highly demanding. In this work, we have discovered 2-aminobenzimidazole-containg ether scaffolds having potent and selective inhibitory potentials against BACE1 enzyme. We have synthesized novel 29 compounds and optimization of aryl linker region resulted in highly potent BACE1 inhibitory activities with EC50 values of 0.05-2.71 µM. The aryloxy-phenyl analogs 20j showed the EC50 value as low as 0.07 µM in the enzyme assay, whereas, the benzyloxyphenyl dervative 24b was comparatively less effective in the enzyme assay. But interestingly the latter was more effective in the cell assay (EC50 value 1.2 µM). While comparing synthesized derivatives in the cell assay using PC12-APPSW cell, compound 27f appeared as the most potent BACE1 inhibitor having EC50 value 0.7 µM. This scaffold also showed high selectivity over BACE2 enzyme and cathepsin D. Furthermore, the research findings were bolstered through the incorporation of molecular docking, molecular dynamics, and DFT studies. We firmly believe that these discoveries will pave the way for the development of a novel class of small-molecule selective BACE1 inhibitors.

Stable biogenic silver nanoparticles from Syzygium nervosum bud extract for enhanced catalytic, antibacterial and antifungal properties.

In the present study, the biosynthesis of stable silver nanoparticles (BioAgNPs) was accomplished successfully for the first time by using an aqueous extract derived from the buds of Syzygium nervosum (SN) as both a reducing and a stabilizing agent. Transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HR-TEM) investigations revealed that the biosynthesized BioAgNPs were predominantly spherical with an average size of 10-30 nm. It was found that the outstanding stability of the BioAgNPs colloidal solution was assigned to the additive effect of the surrounding protective organic layer and the highly negatively charged surface of the nanoparticles. Consequently, good antibacterial activity was demonstrated by the colloidal BioAgNPs solution against four distinct bacterial strains, including Gram-positive S. aureus and B. subtilis as well as Gram-negative E. coli and S. typhi. Interestingly, the biosynthesized BioAgNPs displayed greater antibacterial activity even when tested at low doses against Gram-negative S. typhi. In addition, the biogenic AgNPs demonstrated a significant level of catalytic activity in the process of converting 2-NP, 3-NP, and 4-NP into aminophenols within 15 min, with reaction rate constants of 9.0 × 10-4, 10 × 10-4, and 9.0 × 10-4 s-1, respectively. BioAgNPs formulations were assessed against anthracnose disease in tea plants and were found to be as effective as the positive control at a dose of 20-fold dilution, but less effective at a dose of 30-fold dilution. Both doses of BioAgNPs formulations significantly suppressed Colletotrichum camelliae (anthracnose disease) without affecting the growth of the tea plants.

Desmodinosides A-E: New Flavonoid C-glycosides from Desmodium heterocarpon var. stigosum with hepatoprotective and antifungal activity.

Five new flavonoid C-glycosides named desmodinosides A-E (1-5) and one known compound, apigenin 6-C-ß-d-xylopyranosyl-2''-O-ß-D-glucopyranoside (6) have been isolated from the methanol extract of the aerial parts of Desmodium heterocarpon var. stigosum. These compounds were determined by 1D and 2D-NMR and HR-MS spectroscopies. The methanol extract of this plant, in particular, demonstrated hepatoprotection and antifungal inhibition. This extract has a remarkable hepatoprotection and activity-dose response with an EC50 of 43.07 µg/mL. The hepatoprotective effect on human liver hepatoma cells (HepG2) of the isolated flavonoid C-glycosides 1-6 was observed. Desmodinosides A-C (1-3) were found to exhibit moderate hepatoprotective activity on HepG2 cells. Of these, compound 2 showed the best hepatoprotective activity with an EC50 value of 74.12 µg/mL. While compounds 1 and 3 displayed EC50 values of 271.21 and 211.99 µg/mL, respectively. Quercetin, a positive control, also caused an EC50 value of 36.42 µg/mL. In addition to having hepatoprotective effect, the methanol extract had an inhibitory effect on the growth of oomycete; it inhibited Phytophthora infestans with IC50 of 13.3 µg/mL and IC90 of 78.7 µg/mL. The oomycete inhibition was directly attributed to compounds 5 and 6, which significantly inhibited P. infestans with IC50 values of 27.4 and 24.7 µg/mL, respectively. Both 5 and 6 and methanol extract were active against P. infestanse in a dose-dependent manner. Our study demonstrated for the first time the new flavonoid C-glycosides from D. heterocarpon var. stigosum and their novel pharmacological properties. The study findings also suggest the plant extract and its metabolites could be used as a new botanical source of bioactive compounds.

Characterization of thymol derivatives from Eupatorium fortunei Turcz. aerial parts.

From the aerial parts of Eupatorium fortunei, four thymol derivatives (1-4) were isolated and structurally elucidated by NMR and mass spectroscopic methods. Of which, a new dimeric thymol derivative (1) was characterized and its absolute configuration was established by electronic circular dichroism quantum method. In addition, the 1D and 2D NMR as well as HR-ESI mass spectral data of 2 were provided for the first time. Compounds 2-4 were evaluated for their inhibitory activity against α-glucosidase and acetylcholinesterase enzymes. All tested compounds showed weak inhibition at the concentration range of 1-256 µg/mL in both enzymatic assays.

Chemical constituents of Desmodium triflorum and their antifungal activity against various phytopathogenic fungi.

In the course of finding new antifungal natural compounds against plant pathogens, the methanol extract of Desmodium triflorum was investigated phytochemically. From n-butanol-soluble fraction, seven compounds (1-7) were isolated and structurally elucidated. Of which, six compounds belong to flavone 6- or 8-C-glycoside class (1-6). Three major compounds (1-3) exhibited moderate in vitro antifungal activity against Sclerotium rolfsii, Fusarium oxysporum f. sp. cubense, and Phytophthora palmivora. Compound 1 (IC50 = 162.1 µg/mL) was most active against S. rolfsii in a dose-dependent manner. At 300 µg/mL, compounds 1 and 2 significantly inhibited P. palmivora, whereas compound 3 lacked effectiveness. In addition, the nanoemulsion of the methanol extract with a droplet size of 12.2 nm displayed an excellent inhibition against S. rolfsii and P. palmivora compared with the normal extract. The presence of 1 (0.846%) and 2 (0.759%) in the methanol extract may attribute to the antifungal activity of D. triflorum. These results proved the potential of D. triflorum and its C-glycoside flavonoids against phytopathogenic fungi for the first time. Besides, an enhancement in the effectiveness of nanoemulsion containing D. triflorum extract against the fungi was confirmed. The structural characteristics of 1 and 2 could be considered to develop new fungicidal substances in the future.

Anti-multiple myeloma potential of resynthesized belinostat derivatives: an experimental study on cytotoxic activity, drug combination, and docking studies.

Multiple myeloma is a deadly cancer that is a complex and multifactorial disease. In the present study, 12 belinostat derivatives (four resynthesized and eight new), HDAC inhibitors, were resynthesized via either Knoevenagel condensation, or Wittig reaction, or Heck reaction. Then an evaluation of the antiproliferative activities against myeloma cells MOPC-315 was carried out. Amongst them, compound 7f was the most bioactive compound with an IC50 of 0.090 ± 0.016 µM, being 3.5-fold more potent than the reference belinostat (IC50 = 0.318 ± 0.049 µM). Furthermore, we also confirmed the inhibitory activity of 7f in a cellular model. Additionally, we found that the inhibitory activity of 7f against histone deacetylase 6 catalytic activity (HDAC6) is more potent than that of belinostat. Finally, we observed the strong synergistic interaction between the derivative 7f and the proteasome bortezomib inhibitor (CI = 0.26), while belinostat and bortezomib showed synergism with a CI value of 0.36. Taken together, the above results suggest that 7f is a promising HDAC inhibitor deserving further investigation.

Clerodane Diterpenoids Identified from Polyalthia longifolia Showing Antifungal Activity against Plant Pathogens.

In the search for new natural resources showing plant disease control effects, we found that the methanol extract of Polyalthia longifolia suppressed fungal disease development in plants. To identify the bioactive substances, the methanol extract of P. longifolia was extracted by organic solvents, and consequently, four new 2-oxo-clerodane diterpenes (1-4), a new 4(3 → 2)-abeo-clerodane diterpene (5), together with ten known compounds (6-16) were isolated and identified from the extracts. Of the new compounds, compound 2 showed a broad spectrum of antifungal activity with moderated minimum inhibitory concentration (MIC) values in a range of 50-100 µg/mL against tested fungal pathogens. Considering with the known compounds, compound 6 showed the most potent antifungal activity with an MIC value in the range of 6.3-12.5 µg/mL. When compound 6 was evaluated for an in vivo antifungal activity against rice blast, tomato late blight, and pepper anthracnose, compound 6 reduced the plant disease by at least 60% compared to the untreated control at concentrations of 250 and 500 µg/mL. Together, our results suggested that the methanol extract of twigs and leaves of P. longifolia and its major compound 6 could be used as a source for the development of eco-friendly plant protection agents.

Comparison of the effect of argon, hydrogen, and nitrogen gases on the reduced graphene oxide-hydroxyapatite nanocomposites characteristics.

In this study, the effect of the argon, nitrogen, and hydrogen gases on the final properties of the reduced graphene oxide- hydroxyapatite nanocomposites synthesized by gas injected hydrothermal method was investigated. Four samples were synthesized, which in the first sample the pressure was controlled by volume change at a constant concentration. In subsequent samples, the pressure inside the autoclave was adjusted by the injecting gases. The initial pressure of the injected gases was 10 bar and the final pressure considered was 25 bar. The synthesized powders were consolidated at 950 °C and 2 MPa by spark plasma sintering method. The final samples were subjected to Vickers indentation analysis. The findings of this study indicate that the injection of argon, hydrogen, and nitrogen gases improved the mechanical properties of the nanocomposites. Injection of gases increased the crystallinity and particle size of hydroxyapatite, and this increase was greater for nitrogen gas than for others. Injection of these gases increased the rate of graphene oxide reduction and in this case the effect of nitrogen gas was greater than the others.

Improving the mechanical behavior of reduced graphene oxide/hydroxyapatite nanocomposites using gas injection into powders synthesis autoclave.

In this study, we show the synthesis of reduced graphene oxide/hydroxyapatite (rGO/HA) composites using a hydrothermal autoclave with argon-15% hydrogen gas injection. This both increases the hydrothermal pressure and uses hydrogen as a reductive agent in the process. The synthesized powders were then consolidated with spark plasma sintering method. The analysis of the consolidated samples included Vickers Indentation technique and cell viability. The results showed that injected gases in the autoclave produced powders with a higher crystallinity compared to synthesis without the gases. Also, hydrogen gas led to increased reduction of GO. The microscopic analysis confirmed existing graphene sheets with folding and wrinkling in the powders and indicated that various preferential directions played a role in the growth of hydroxyapatite crystals. The results showed that in general, graphene sheets increased the mechanical properties of HA. In the samples synthesized with injected gases, this increase was more significant. Interface analysis results indicate that reduced graphene oxide (rGO)/HA interface is likely coherent. These nanocomposites were biocompatible and showed some hydrophobicity compared to pure HA.

Control of root-knot nematodes using Waltheria indica producing 4-quinolone alkaloids.

BACKGROUND: Waltheria indica exhibited strong nematocidal activity against Meloidogyne incognita, a causal agent of root-knot nematode disease. This study aimed to characterize the nematocidal metabolites and to evaluate the efficacy of the formulated extract of W. indica in the biological control of M. incognita under both pot and field conditions. RESULTS: Three 4-quinolone alkaloids, 5'-methoxywaltherione A, waltherione A and waltherione C, were isolated and characterized as nematocidal metabolites. 5'-Methoxywaltherione A and waltherione A caused high mortality in juveniles of Meloidogyne arenaria, Meloidogyne hapla, M. incognita and Bursaphelenchus xylophilus, whereas waltherione C exhibited significant nematocidal activity against only root-knot nematodes. In pot experiments, application of a wettable powder-type formulation of the ethyl acetate extract of W. indica (W. indica WP20) at 26.7, 53.4 and 106.8 mg a.i. kg-1 soil significantly reduced the formation of galls and egg masses on the roots of tomato plants in a dose-dependent manner. In addition, application of 20 mg a.i. per plant W. indica WP20 effectively reduced gall formation on the roots of melon plants and population density of nematode in soil compared with untreated control under field conditions. CONCLUSION: W. indica can be used as an effective botanical nematicide in the eco-friendly control of root-knot nematode disease. © 2019 Society of Chemical Industry.

Identification of novel compounds, oleanane- and ursane-type triterpene glycosides, from Trevesia palmata: their biocontrol activity against phytopathogenic fungi.

Plants contain a number of bioactive compounds that exhibit antimicrobial activity, which can be recognized as an important source of agrochemicals for plant disease control. As part of our search for new antimicrobial agents from natural sources, we found that a crude methanol extract of Trevesia palmata exhibited a promising antifungal activity against phytopathogenic fungi, such as Magnaporthe oryzae and Botrytis cinerea. Furthermore, based on activity-guided fractionation, we isolated five antifungal compounds from the methanol extract of T. palmata: two new triterpene glycosides (TPGs), TPG1 (hederagenin-3-O-ß-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranoside) and TPG5 (3-O-α-L-rhamnopyranosyl asiatic acid), along with three known TPGs (TPG2 [macranthoside A], TPG3 [α-hederin], and TPG4 [ilekudinoside D]). The chemical structures of the TPGs were determined by spectroscopic analyses and by comparison with literature data. An in vitro antifungal bioassay revealed that except for TPG4 (ilekudinoside D; IC50 >256 µg/ml), the other TPGs exhibited strong antifungal activities against the rice blast pathogen M. oryzae with IC50 values ranging from 2-5 µg/ml. In particular, when the plants were treated with compound TPG1 (500 µg/ml), disease control values against rice blast, tomato grey mold, tomato late blight, and wheat leaf rust were 84, 82, 88, and 70%, respectively, compared to the non-treatment control. Considering the in vitro and in vivo antifungal activities of the TPGs and the T. palmata methanol extracts, our results suggest that T. palmata can be a useful source to develop new natural fungicides.

Biomechanical evaluation of annulus fibrosus repair with scaffold and soft anchors in an ex vivo porcine model.

INTRODUCTION: Altered biomechanical properties, due to intervertebral disc (IVD) degeneration and missing nucleus fibrosus, could be thought as one of the reasons for the back pain many herniation patients experience after surgery. It has been suggested to repair annulus fibrosus (AF) to restore stability and allow nucleus pulposus (NP) replacement and furthermore prevent reherniation. The aim of this study was to evaluate a new method for closing a defect in AF for use in herniation surgery. METHODS: Our repair method combines a polycaprolactone (PCL) scaffold plugging herniation and soft anchors to secure the plug. Ex vivo biomechanical testing was carried out in nine porcine lumbar motion segments. Flexion-extension, lateral bending and rotation were repeated three times: first in healthy specimens, second with a full thickness circular defect applied, and third time with the specimens repaired. Finally push out tests were performed to check whether the plug would remain in. RESULTS: Tests showed that applying a defect to the AF increases the range of motion (ROM), neutral zone (NZ) and neutral zone stiffness (NZS). In flexion/extension it was found significant for ROM, NZ, and NZS. For lateral bending and rotation a significant increase in ROM occurred. After AF repair ROM, NZ and NZS were normalized. All plugs remained in the AF during push out test up until 4000 N, but NP was squeezed out through the pores of the scaffold. DISCUSSION: A defect in the AF changes the biomechanical properties in the motion segment, changes that point to instability. Repairing the defect with a PCL plug and soft anchors brought the biomechanical behavior back to native state. This concept is promising and might be a viable way to repair the IVD after surgery.

Calcium-MicroRNA Complex-Functionalized Nanotubular Implant Surface for Highly Efficient Transfection and Enhanced Osteogenesis of Mesenchymal Stem Cells.

Controlling mesenchymal stem cell (MSC) differentiation by RNA interference (RNAi) is a promising approach for next-generation regenerative medicine. However, efficient delivery of RNAi therapeutics is still a limiting factor. In this study, we have developed a simple, biocompatible, and highly effective delivery method of small RNA therapeutics into human MSCs (hMSCs) from an implant surface by calcium ions. First, we demonstrated that simple Ca/siRNA targeting green fluorescent protein (GFP) nanocomplexes were able to efficiently silence GFP in GFP-expressing hMSCs with adequate Ca2+ concentration (>5 mM). In addition, a single transfection could obtain a long-lasting silencing effect for more than 2 weeks. All three of the main endocytosis pathways (clathrin- and caveolin-mediated endocytosis and macropinocytosis) were involved in the internalization of the Ca/siRNA complexes by MSCs, and macropinocytosis plays the most dominant role. Furthermore, the Ca/siRNA complexes could be efficiently loaded onto the titanium implant surface when pretreated with anodization to create a nanotube (NT) layer. Because of the hydrophilic property of the NT surface, the Ca/siRNA was quickly loaded (less than 4 h) with high efficiency (nearly 100%), forming an even amorphous coating. The Ca/siRNA-coated NT surface showed an initial burst release of 80% of the siRNA complexes over 2 h, which is adequate to achieve robust gene silencing of attached hMSCs. To demonstrate the therapeutic potential of our Ca/siRNA coating technology, Ca/antimiR-138 complexes were loaded on to the NT surface, which strongly enhanced the osteogenic differentiation of hMSCs. In conclusion, our findings suggest that Ca2+ is an effective and biocompatible carrier to deliver small RNA therapeutics into hMSCs, both in solution and from functionalized surfaces, which provides a novel approach to control the MSC differentiation and tissue regeneration.

Antifungal activity of sterols and dipsacus saponins isolated from Dipsacus asper roots against phytopathogenic fungi.

The in vivo antifungal activity of crude extracts of Dipsacus asper roots was evaluated against the phytopathogenic fungi Botrytis cinerea, Colletotrichum coccodes, Blumeria graminis f. sp. hordei, Magnaporthe grisea, Phytophthora infestans, Puccinia recondita and Rhizoctonia solani using a whole-plant assay method. Ethyl acetate and acetone extracts, at 1000µg/mL, suppressed the development of tomato gray mold (TGM) and tomato late blight (TLB) by 90%. Through bioassay-guided isolation, five antifungal substances were isolated from the D. asper roots and identified as ß-sitosterol (1), campesterol (2), stigmasterol (3), cauloside A (4) and a novel dipsacus saponin, named colchiside (3-O-ß-d-xylopyranosyl-23-O-ß-d-glucopyranosyl-28-O-ß-d-(6-O-acetyl)-glucopyranosyl hederagenin) (5). Of those, cauloside A (4) displayed the greatest antifungal efficacy against rice blast, TGM and TLB. Colchiside (5) moderately suppressed the development of TLB, but exhibited little effect against the other diseases. The synergistic effects of the isolated compounds against TLB were also assessed. Synergistic and additive interactions were observed between several of the sterol compounds. This study indicated that the crude extracts of, and bioactive substances from, the roots of D. asper suppress TGM and TLB. In addition, cauloside A (4) and colchiside (5) could be used as antifungal lead compounds.

Characterization and mechanisms of anti-influenza virus metabolites isolated from the Vietnamese medicinal plant Polygonum chinense.

BACKGROUND: Polygonum chinense Linn. is a common medicinal plant in Southeast Asia and has been used in traditional medicine in Vietnam. The plant contains phytochemicals with various biological properties; however, its antiviral effect has not yet been demonstrated. This study was aimed to evaluate the anti-influenza virus activity of crude extracts of P. chinense, to characterize antiviral metabolites therefrom and to investigate their mechanisms of antiviral action. METHODS: The methanol (MeOH) extract and organic solvent layers of P. chinense were prepared by extraction and partition with relevant solvents. The ethyl acetate (EtOAc) layer showing antiviral activity was chromatographed repeatedly on SiO2 and Sephadex LH-20 columns to give eight pure metabolites. Their chemical structures were determined by NMR and MS spectral data. Anti-influenza virus activity of the eight metabolites against virus strains A/Puerto Rico/8/34 (H1N1, PR8), A/Hong Kong/8/68 (H3N2, HK) and B/Lee/40 (Lee) was evaluated on the basis of cytopathic effect (CPE) and plaque inhibition assays. Time-of-addition, confocal microscopy and neuraminidase inhibition assay were performed for mode-of-action studies of active ingredients. RESULTS: The MeOH extract of P. chinense showed anti-influenza virus activity with EC50 values ranging from 38.4 to 55.5 µg/mL in a CPE inhibition assay. Among the eight pure metabolites isolated from P. chinense, ellagic acid (PC5), methyl gallate (PC7) and caffeic acid (PC8) significantly inhibited viral replication in a dose-dependent manner in both plaque inhibition and CPE inhibition assays with EC50 values ranging from 14.7 to 81.1 µg/mL and CC50 values higher than 300 µg/mL. Mode-of-action studies suggested that PC5 and PC7 suppress virus entry into or replication in cells, while PC8 targets influenza viral neuraminidase, even oseltamivir-resistant one. CONCLUSION: These results demonstrated that P. chinense and its metabolites possess effective anti-influenza virus activities. The botanical materials of P. chinense could be a promising multitargeted inhibitor of influenza A and B viruses and applied to development of a novel herbal medicine.

Dental pulp-derived stromal cells exhibit a higher osteogenic potency than bone marrow-derived stromal cells in vitro and in a porcine critical-size bone defect model.

INTRODUCTION: The osteogenic differentiation of bone marrow-derived mesenchymal stromal cells (BMSCs) was compared with that of dental pulp-derived stromal cells (DPSCs) in vitro and in a pig calvaria critical-size bone defect model. METHODS: BMSCs and DPSCs were extracted from the tibia bone marrow and the molar teeth of each pig, respectively. BMSCs and DPSCs were cultured in monolayer and on a three-dimensional (3D) polycaprolactone (PCL) - hyaluronic acid - tricalcium phosphate (HT-PCL) scaffold. Population doubling (PD), alkaline phosphatase (ALP) activity, and calcium deposition were measured in monolayer. In the 3D culture ALP activity, DNA content, and calcium deposition were evaluated. Six non-penetrating critical-size defects were made in each calvarium of 14 pigs. Three paired sub-studies were conducted: (1) empty defects vs. HT-PCL scaffolds; (2) PCL scaffolds vs. HT-PCL scaffolds; and (3) autologous BMSCs on HT-PCL scaffolds vs. autologous DPSCs on HT-PCL scaffolds. The observation time was five weeks. Bone volume fractions (BV/TV) were assessed with micro-computed tomography (µCT) and histomorphometry. RESULTS AND DISCUSSION: The results from the in vitro study revealed a higher ALP activity and calcium deposition of the DPSC cultures compared with BMSC cultures. Significantly more bone was present in the HT-PCL group than in both the pure PCL scaffold group and the empty defect group in vivo. DPSCs generated more bone than BMSCs when seeded on HT-PCL. In conclusion, DPSCs exhibited a higher osteogenic potential compared with BMSCs both in vitro and in vivo, making it a potential cell source for future bone tissue engineering.

In vitro antibacterial activity of selected medicinal plants traditionally used in Vietnam against human pathogenic bacteria.

BACKGROUND: Medicinal plants are widely used for the treatment of different infectious diseases. Infectious diseases caused by bacteria have a large impact on public health. This study aimed to determine the in vitro antibacterial activity of the medicinal plants traditionally used in Vietnam against the bacterial strains associated with infectious diseases. METHODS: Methanol extracts of twelve Vietnamese medicinal plants were tested for their antibacterial activity against five bacterial species including Gram-positive bacteria (Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) using the broth microdilution method. RESULTS: All the plant extracts showed antibacterial activity, especially against Gram-positive bacteria (Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus). Baeckea frutescens extract revealed a potent activity against the Gram-positive bacteria with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 62.5 µg/ml. High activity against all the three Gram-positive bacteria was also observed for the extracts of Cratoxylum formosum ssp. pruniflorum, Pogostemon cablin, and Pedilanthus tithymaloides with MICs of 125, 125 and 250 µg/ml and MBCs of 125-250, 125-250 and 250-500 µg/ml, respectively. The extracts of C. formosum ssp. pruniflorum and P. tithymaloides showed a broad-spectrum antibacterial activity against all the bacteria tested with the MICs of 125-2,000 µg/ml. CONCLUSION: This study indicates clear evidence supporting the traditional use of the plants in treating infectious diseases related to bacteria. In particular, these plant species showed moderate to high antibacterial activity against the Gram-positive bacteria tested.

Topography-Guided Proliferation: Distinct Surface Microtopography Increases Proliferation of Chondrocytes In Vitro.

Chondrocyte-based cartilage repair techniques require control of articular chondrocyte expansion ex vivo. Articular chondrocytes have limited availability, and prolonged culturing to obtain a cell number sufficient for clinical use often results in phenotypic alterations and increased costs. In this study, we applied a screening library consisting of micrometer-sized topographical features, termed biosurface structure array (BSSA), to identify specific topographical microstructures affecting the proliferation of human chondrocytes in passage 1 (P1) or 2 (P2). The BSSA library comprised 10 patterns and 16 combinations of pillar size (X) and interpillar gap size (Y). Specific microstructures significantly increased the chondrocytes' proliferative responsiveness in term of patterns, X and Y for P2 compared with P1. The P1 and P2 chondrocytes responded independently to similar patterns after 4 days of culturing, whereas only chondrocytes at P2 responded to specific microstructures with Y = 1 µm and X = 2, 4 µm by a 2.3- and 4.4-fold increased proliferation, respectively. In conclusion, these findings indicate that specific surface topographies promote chondrocyte proliferation and may, indeed, be a tool to control the behavior of chondrocytes in vitro.