Low-level laser therapy with different irradiation methods modulated the response of bone marrow mesenchymal stem cells in vitro.

Low-level laser therapy (LLLT) also known as photobiomodulation is a treatment to change cellular biological activity. The exact effects of LLLT remain unclear due to the different irradiation protocols. The purpose of this study was to investigate the effects of LLLT by three different irradiation methods on the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro. BMSCs were inoculated in 24-well plates and then irradiated or not (control) with a laser using three different irradiation methods. The irradiation methods were spot irradiation, covering irradiation, and scanning irradiation according to different spot areas (0.07 cm2 or 1.96 cm2) and irradiation areas (0.35 cm2 or 1.96 cm2), respectively. The laser was applied three times at energy densities of 4 J/cm2. The cell proliferation by CCK-8. ALP activity assay, alizarin red, and quantitative real-time polymerase chain reaction (RT-PCR) were performed to assess osteogenic differentiation and mineralization. Increases in cell proliferation was obvious following irradiation, especially for covering irradiation. The ALP activity was significantly increased in irradiated groups compared with non-irradiated control. The level of mineralization was obviously improved following irradiation, particularly for covering irradiation. RT-PCR detected significantly higher expression of ALP, OPN, OCN, and RUNX-2 in the group covering than in the others, and control is the lowest. The presented results indicate that the biostimulative effects of LLLT on BMSCs was influenced by t he irradiation method, and the covering irradiation is more favorable method to promote the proliferation and osteogenic differentiation of BMSCs.

Erratum to "Evaluation of the Mechanism of Modified Lingguizhugan Decoction in the Treatment of Nonalcoholic Fatty Liver Disease".

[This corrects the article DOI: 10.1155/2022/4576679.].

Fabrication and in vitro evaluation of 3D printed porous silicate substituted calcium phosphate scaffolds for bone tissue engineering.

Silicate-substituted calcium phosphate (Si-CaP) ceramics, alternative materials for autogenous bone grafting, exhibit excellent osteoinductivity, osteoconductivity, biocompatibility, and biodegradability; thus, they have been widely used for treating bone defects. However, the limited control over the spatial structure and weak mechanical properties of conventional Si-CaP ceramics hinder their wide application. Here, we used digital light processing (DLP) printing technology to fabricate a novel porous 3D printed Si-CaP scaffold to enhance the scaffold properties. Scanning electron microscopy, compression tests, and computational fluid dynamics simulations of the 3D printed Si-CaP scaffolds revealed a uniform spatial structure, appropriate mechanical properties, and effective interior permeability. Furthermore, compared to Si-CaP groups, 3D printed Si-CaP groups exhibited sustained release of silicon (Si), calcium (Ca), and phosphorus (P) ions. Furthermore, 3D printed Si-CaP groups had more comprehensive and persistent osteogenic effects due to increased osteogenic factor expression and calcium deposition. Our results show that the 3D printed Si-CaP scaffold successfully improved bone marrow mesenchymal stem cells (BMSCs) adhesion, proliferation, and osteogenic differentiation and possessed a distinct apatite mineralization ability. Overall, with the help of DLP printing technology, Si-CaP ceramic materials facilitate the fabrication of ideal bone tissue engineering scaffolds with essential elements, providing a promising approach for bone regeneration.

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.

Damnacanthal isolated from morinda species inhibited ovarian cancer cell proliferation and migration through activating autophagy.

BACKGROUND: Ovarian cancer is a very common gynecological malignant tumor. Natural products are important sources of chemotherapy drugs for ovarian cancer. Damnacanthal is an anthraquinone derivative with anti-cancer pharmacological properties. OBJECTIVE: This study aimed to investigate the mechanisms underlying damnacanthal's effects against ovarian cancer. METHODS: In vitro experiments, CCK8, colony formation and flow cytometry assays were used to evaluate the anti-ovarian cancer effect of damnacanthal on SKVO3 and A2780 cells. The wound healing tests and the transwell invasion assays were used to detect the migration and infiltration of ovarian cancer cells. Western Blot assays and immunofluorescence staining were used to measure autophagy levels. In vivo experiments, the anti-ovarian cancer effect of damnacanthal was further evaluated in a xenograft nude mouse model of SKVO3 cells. RESULTS: Damnacanthal induced significant cell death and apoptosis, as well as significant inhibition in migration and invasion, in SKVO3 and A2780 cells, Furthermore, damnacanthal induced cell cycle arrest by increasing the protein levels of p27Kip1 and decreasing cyclin D1 levels. In addition, damnacanthal induced a significant accumulation of autophagosomes, accompanied with an increase in LC3II protein levels, and a decrease in p62 protein levels. 3-methyladenine, an autophagy formation inhibitor, significantly mitigated the damnacanthal-induced apoptosis and migration hindrance, as well as the decline in cell viability. Furthermore, the inactivation of ERK and its downstream effector mTOR signaling pathways, rather than Akt or P38 pathway, were involved in damnacanthal's activation in autophagy. In addition, TBHQ, an ERK activator, significantly inhibited damnacanthal-boosted LC3 II levels and autophagosome accumulation, and reversed damnacanthal-induced cell death, apoptosis, cell cycle arrest and migration hindrance. Finally, the anti-ovarian cancer effect of damnacanthal was confirmed in the orthotopic xenograft model of SKVO3 cells in nude mice, with tumor growth being significantly inhibited comparably to the efficacy of cisplatin. Damnacanthal was also synergistic with cisplatin and showed inhibition in cisplatin-resistant ovarian cancer cells. CONCLUSION: Damnacanthal inhibited the growth of ovarian cancer via the ERK/mTOR/autophagy signaling cascade, indicating that it may be a potential anti-ovarian cancer drug candidate.

Evaluation of the Mechanism of Modified Lingguizhugan Decoction in the Treatment of Nonalcoholic Fatty Liver Disease.

Nonalcoholic steatohepatitis (NASH) may develop into cirrhosis and liver cancer, which imposes a great burden to individuals and society. Lingguizhugan decoction is a commonly used dampness dispelling medication in traditional Chinese medicine and is often used to treat those with phlegm and retained fluid from various causes and pathogeneses. The objective of this study was to explore the effect and mechanism of modified Lingguizhugan decoction (MLGZG) on lipid metabolism and the inflammatory response to identify a theoretical basis to promote its clinical application in NASH therapy. After treatment with MLGZG for 8 weeks, the weight of high-fat-diet (HFD)-fed NASH rats was significantly higher than that of rats in the normal group, and the weights in each dose group were significantly lower than those in the model group. The treatment groups (low, medium, and high doses) had different degrees of improvement in the changes in hepatocyte tissue structure, steatosis, and inflammatory infiltration. Compared with that in the normal group, the expression of TNF receptor-associated factor-3 (TRAF-3) and nuclear factor κB (NFκB) in the model group significantly increased to varying degrees. Compared with the NASH group, the treatment groups (low, middle, and high doses) showed modified lipid metabolism gene expression and decreased inflammatory factor expression levels. Modified Lingguizhugan decoction can improve the general condition of rats with nonalcoholic fatty liver disease by reducing the expression levels of TRAF3, NF-κB, the Toll-like receptor 4 (TLR-4) pathway, and related proteins, as well as the expression levels of lipid metabolism genes and cytokines.

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.

Current development of integrated web servers for preclinical safety and pharmacokinetics assessments in drug development.

In drug development, preclinical safety and pharmacokinetics assessments of candidate drugs to ensure the safety profile are a must. While in vivo and in vitro tests are traditionally used, experimental determinations have disadvantages, as they are usually time-consuming and costly. In silico predictions of these preclinical endpoints have each been developed in the past decades. However, only a few web-based tools have integrated different models to provide a simple one-step platform to help researchers thoroughly evaluate potential drug candidates. To efficiently achieve this approach, a platform for preclinical evaluation must not only predict key ADMET (absorption, distribution, metabolism, excretion and toxicity) properties but also provide some guidance on structural modifications to improve the undesired properties. In this review, we organized and compared several existing integrated web servers that can be adopted in preclinical drug development projects to evaluate the subject of interest. We also introduced our new web server, Virtual Rat, as an alternative choice to profile the properties of drug candidates. In Virtual Rat, we provide not only predictions of important ADMET properties but also possible reasons as to why the model made those structural predictions. Multiple models were implemented into Virtual Rat, including models for predicting human ether-a-go-go-related gene (hERG) inhibition, cytochrome P450 (CYP) inhibition, mutagenicity (Ames test), blood-brain barrier penetration, cytotoxicity and Caco-2 permeability. Virtual Rat is free and has been made publicly available at https://virtualrat.cmdm.tw/.

Characterisation of mechanical and surface properties of novel biomimetic interpenetrating alumina-polycarbonate composite materials.

OBJECTIVE: To determine the mechanical and surface characteristics of two novel biomimetic interpenetrating phase alumina-polycarbonate (Al2O3-PC) composite materials, comprising aligned honeycomb-like porous ceramic preforms infiltrated with polycarbonate polymer. METHOD: Two composite materials were produced and characterised. Each comprised a porous structure with a ceramic-rich (polymer-poor) top layer, graduated through to a more porous ceramic-poor (polymer-rich) bottom layer. In addition, pure polycarbonate and dense alumina specimens were subjected to the same characterisation namely: density, compression, three-point bend, hardness, surface loss and surface roughness testing. Scanning electron microscopy and micro computerised tomography were employed for structural examination. RESULTS: Three-dimensional aligned honeycomb-like ceramic structures were produced and full interpenetration of the polymer phase was observed using MicroCT. Depending on the ceramic volume in the initial aqueous ceramic suspension, the density of the final interpenetrating composites ranged from 2.64 to 3.01g/cm3, compressive strength ranged from 192.43 to 274.91MPa, flexural strength from 105.54 to 148.47MPa, fracture toughness from 2.17 to 3.11MPa.m½, hardness from 0.82 to 1.52GPa, surface loss from 0.71 to 1.40µm and surface roughness, following tooth brushing, from 0.70 to 0.99µm. Composite specimens showed characteristic properties part way between enamel and polycarbonate. SIGNIFICANCE: There was a correlation between the initial solid ceramic loading in the aqueous suspension, used to produce the porous ceramic scaffolds, and the subsequent characteristic properties of the composite materials. These novel composites show potential as aesthetic orthodontic bracket materials, as their properties fit part way between those of ceramic, enamel and polycarbonate.

Antinociceptive Effects of Shenling Baizhu through PI3K-Akt-mTOR Signaling Pathway in a Mouse Model of Bone Metastasis with Small-Cell Lung Cancer.

Shenling Baizhu additive powder (SLBZ-AP), a formulation of a variety of natural medicinal plants, has clinical efficacy in treating cancers in previous studies. We explored the effect of SLBZ-AP in bone metastasis of lung cancer (BMLC) mice, and the possible mechanism involved was further investigated in the present study. Mice model of BMLC was made and treated with SLBZ-AP. Pain behavioral tests were performed to explore the effect on BMLC-induced pain in mice. TUNEL staining was used to investigate apoptosis. The mRNA expression of markers in the PI3K/Akt/mTOR pathway was measured by qPCR, and protein expression was detected by western blotting and immunohistochemistry analysis. SLBZ-AP relieved BMLC-induced pain and prolonged animals' survival, promoted cell apoptosis in the marrow from the tibia of BMLC mice, and inhibited mRNA and protein expression of AKT, mTOR, P70S6, and VEGF, as well as protein expression of p-AKT, p-mTOR, p-P70S6, and VEGF upregulation in the marrow of tibia induced by BMLC, an effect which was similar to rapamycin. Our results suggested that SLBZ-AP may have antinociceptive effect and prolong survival of BMLC mice at least partially by inhibiting cell proliferation and promoting apoptosis through the PI3K/Akt/mTOR signaling pathway. SLBZ-AP may be a potential candidate for BMLC therapy.

The effect of green tea supplementation on obesity: A systematic review and dose-response meta-analysis of randomized controlled trials.

The effects of green tea (GT) in obese subjects have been evaluated in different studies, but no consensus has been obtained due to the heterogeneity of the results. The dosage, the type of extract, and the duration of the intervention are the main contributors to the heterogeneity of the results. Therefore, the present systematic review and meta-analysis aimed to evaluate the efficacy and dose-response relationship of GT. Several databases were searched from inception to September 2019 to identify clinical trials that examined the influence of GT supplements on obesity indices in humans. Combined results using the random-effects model indicated that body weight (WMD: -1.78 kg, 95% CI: -2.80, -0.75, p = .001) and body mass index (BMI) (WMD: -0.65 kg/m2 , 95% CI: -1.04, -0.25, p = .001) did change significantly following GT administration. The reduction in waist circumference (WC) after GT consumption was significant in subjects in trials employing GT ≥800 mg/day (WMD: -2.06 cm) and with a treatment duration <12 weeks (WMD: -2.39 cm). Following the dose-response evaluation, GT intake did alter body weight, with a more important reduction when the GT dosage was <500 mg/day and the treatment duration was of 12 weeks. The results of present meta-analysis study support the use of GT for the improvement of obesity indices. Thus, we suggest that the use of GT can be combined with a balanced and healthy diet and regular physical exercise in the management of obese patients.

The Protective Effect of Different Polar Solvent Extracts of Er Miao San on Rats with Adjuvant Arthritis.

OBJECTIVE: The aim of this study was to evaluate the antiarthritic effects of different polar solvent extracts of Er Miao San (EMS) on model rats with adjuvant arthritis (AA) and screen the effective pats of EMS in the treatment of arthritis. METHODS: Four different polar solvent extracts of EMS such as petroleum ether (PE), methylene chloride (CH2Cl2), ethyl acetate (EtOAc), and n-butanol (n-butanol (. RESULTS: Administration of EtOAc and CH2Cl2 parts remarkably inhibited the paw swelling, decreased the index of arthritis, decreased the body weight loss, and improved the changes of histopathology. Furthermore, the concentrations of proinflammatory cytokines (TNF-α, IL-1ß, and IL-6) were significantly lower, while the anti-inflammatory cytokine (IL-10) was remarkably higher compared with that in the model group. And the result of UHPLC analysis indicated that the effective parts of EMS contain berberine and atractylodin. CONCLUSIONS: EtOAc and CH2Cl2 are the effective parts of EMS that can improve arthritis. In particular, berberine and atractylodin may be responsible for the antiarthritic activity of EMS. This research provided pharmacological and chemical foundation for the application of EMS in treating rheumatoid arthritis (RA).

Anti-Inflammatory Effects of Different Elution Fractions of Er-Miao-San on Acute Inflammation Induced by Carrageenan in Rat Paw Tissue.

BACKGROUND Er-Miao-San (EMS) is used in traditional Chinese medicine. This study aimed to investigate the effect of different elution fractions of EMS on acute inflammation induced by carrageenan in the rat paw and the possible mechanisms of action. MATERIAL AND METHODS Different aqueous fractions of EMS added to an AB-8 macroporous resin column and eluted with 0, 30%, 60%, and 90% ethanol. The content of berberine was evaluated by ultra-performance liquid chromatography (UPLC). Following injection of carrageenan and elution fractions of EMS into the rat paw, the volume of edema, levels of prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1ß, and IL-10 in the rat tissue were quantified by enzyme-linked immunosorbent assay (ELISA). Myeloperoxidase (MPO) activity and nitric oxide (NO) levels were measured by spectrophotometry. RESULTS The 60% and 90% ethanol elution fractions of EMS contained berberine, and both inhibited edema after carrageenan injection, with inhibitory rates of 31.04-40.86% and 48.84-52.18%, respectively, and with a significant reduction in MPO activity and NO production. The 60% ethanol elution fraction of EMS significantly decreased IL-1ß levels and increased IL-10 levels, and the 30%, 60%, and 90% ethanol EMS elution fractions considerably reduced the levels of TNF-alpha. The 60% and 90% ethanol EMS elution fractions significantly reduced PGE2 levels in the rat paw. CONCLUSIONS The 60% and 90% ethanol elution fractions of EMS had an anti-inflammatory effect following injection of carrageenan in the rat paw.

Fabrication and characterisation of a novel biomimetic anisotropic ceramic/polymer-infiltrated composite material.

OBJECTIVE: To fabricate and characterise a novel biomimetic composite material consisting of aligned porous ceramic preforms infiltrated with polymer. METHOD: Freeze-casting was used to fabricate and control the microstructure and porosity of ceramic preforms, which were subsequently infiltrated with 40-50% by volume UDMA-TEGDMA polymer. The composite materials were then subjected to characterisation, namely density, compression, three-point bend, hardness and fracture toughness testing. Samples were also subjected to scanning electron microscopy and computerised tomography (Micro-CT). RESULTS: Three-dimensional aligned honeycomb-like ceramic structures were produced and full interpenetration of the polymer phase was observed using micro-CT. Depending on the volume fraction of the ceramic preform, the density of the final composite ranged from 2.92 to 3.36g/cm3, compressive strength ranged from 206.26 to 253.97MPa, flexural strength from 97.73 to 145.65MPa, hardness ranged from 1.46 to 1.62GPa, and fracture toughness from 3.91 to 4.86MPam1/2. SIGNIFICANCE: Freeze-casting provides a novel method to engineer composite materials with a unique aligned honeycomb-like interpenetrating structure, consisting of two continuous phases, inorganic and organic. There was a correlation between the ceramic fraction and the subsequent, density, strength, hardness and fracture toughness of the composite material.

NP-StructurePredictor: Prediction of Unknown Natural Products in Plant Mixtures.

Identification of the individual chemical constituents of a mixture, especially solutions extracted from medicinal plants, is a time-consuming task. The identification results are often limited by challenges such as the development of separation methods and the availability of known reference standards. A novel structure elucidation system, NP-StructurePredictor, is presented and used to accelerate the process of identifying chemical structures in a mixture based on a branch and bound algorithm combined with a large collection of natural product databases. NP-StructurePredictor requires only targeted molecular weights calculated from a list of m/z values from liquid chromatography-mass spectrometry (LC-MS) experiments as input information to predict the chemical structures of individual components matching the weights in a mixture. NP-StructurePredictor also provides the predicted structures with statistically calculated probabilities so that the most likely chemical structures of the natural products and their analogs can be proposed accordingly. Four data sets consisting of different Chinese herbs with mixtures containing known compounds were selected for validation studies, and all their components were correctly identified and highly predicted using NP-StructurePredictor. NP-StructurePredictor demonstrated its applicability for predicting the chemical structures of novel compounds by returning highly accurate results from four different validation case studies.

The effect of treatment with α-glycosidases from Bacteroides fragilis on the survival of rat erythrocytes in the circulation.

BACKGROUND: It has been demonstrated recently that α1,3-galactosidase from Bacteroides fragilis can efficiently convert human group B red blood cells (RBC) to group O cells. In addition, in vitro data indicated that the enzymatic conversion process did not affect the physiological or metabolic parameters of the RBC. The aim of this study was to investigate the lifespan of enzyme- treated RBC in vivo in the circulation. MATERIALS AND METHODS: This was an experimental, randomised study. The rat was selected as the experimental subject because it expresses α-1,3galactosyl on its RBC. The efficiency of Galα1,3Gal epitope removal from RBC treated with α1,3-galactosidase was tested before the transfusion experiment to track the survival of RBC in the circulation. The animals were divided into three groups and injected via the tail vein with native, mock-treated or enzyme-treated RBC labelled with fluorescein isothiocyanate. The survival rates of the fluorescently labelled RBC were monitored by flow cytometry. RESULTS: Flow cytometry showed that α-galactosidase (0.02 mg/mL for RBC with a haematocrit of 30%) efficiently removed Galα1,3Gal epitopes from rat erythrocytes, although small amounts of remaining Galα1,3Gal epitopes were still detected. The in vivo data demonstrated that the half-life of enzyme-treated RBC was a little shorter than that of native RBC. However, the 24-hour survival fractions of native, mock-treated and enzyme-treated RBC were virtually identical. Most importantly, the enzyme-treated RBC, like the native RBC, were still detectable 35 days after transfusion. DISCUSSION: Our results indicate that α-glycosidase treatment had little effect on the in vivo survival kinetics of RBC. These data add further support to the feasibility of translating enzymatic conversion technology into clinical practice.

[Determination of theacrine in rat plasma by RP-HPLC].

OBJECTIVE: To establish a method for the determination of theacrine in rat plasma after ig. administration of theacrine. METHOD: Blood sample was taken timely from the eyes canthus of rats. Plasma was isolated and the protein was precipitated by ethyl acetate. Then the plasma concentration of theacrine was determined with RP-HPLC. Caffeine was used as the internal standard. The chromatographic conditions were as follows: Phenomenex Luna C18 (4.6 mm x 250 mm, 5 microm) at 25 degrees C, a mixture of methanol-water (25: 75) as the mobile phase, at the flow rate of 1.0 mL x min(-1) and the detection wavelength of 290 nm. RESULT: The linear range of theacrine was 0.5-100 mg x L(-1) (R2 = 0.998 9). The lower limit of quantification was 0.5 mg x L(-1). The intra-day RSD was 1.49% 4.40% and inter-day RSD was 0.80% -10.27%. The average extraction recoveries of theacrine were 90.3% -95.8% at concentrations of 0.5, 5.0, 50 mg x L(-1). The main pharmacokinetic parameters after ig. administration of theacrine at concentration of 30 mg x kg(-1) were as follow: C(max) (35.45 +/- 30 2.68) mg x L(-1), t(max) (0.51 +/- 0.13) h, t1/2 (3.13 +/- 1.37) h, AUC(0-infinity) (2.65.39 +/- 94.71) mg x L(-1) x h. CONCLUSION: The method has been confirmed to be simple, stable, reproducible and with high specificity, and can be used for the pharmacokinetic study of theacrine in rats.

Embossing of micropatterned ceramics and their cellular response.

The aim of this work is to investigate the use of microtopographies in providing physical cues to modulate the cellular response of human mesenchymal stem cells on ceramics. Two microgrooved patterns (100 µm/50 µm, 10 µm/10 µm groove/pitch) were transcribed reversely onto alumina green ceramic tapes via an embossing technique followed by sintering. Characterization of the micropatterned alumina surfaces and their cellular response was carried out. Spread and polygonal cell morphologies were observed on the wider groove (50 µm/100 µm) surface. Cells seeded onto the narrow groove (10 µm/10 µm) surface aligned themselves alongside the grooves, resulting in more elongated cell morphology. More osteoid matrix nodules shown by osteopontin and osteocalcin biomarkers were detected on the larger grooved surfaces after cell culture of 21 days, indicating a greater level of osteogenicity. This study has shown that micropatterned wider groove (50 µm) topographies are more suitable surfaces for improving osseointegration of ceramic implants.

Fabrication and characterization of biomimetic ceramic/polymer composite materials for dental restoration.

OBJECTIVE: Conventional dental composites with randomly dispersed inorganic particles within a polymer matrix fail to recapitulate the aligned and anisotropic structure of the dentin and enamel. The aim of the study was to produce a biomimetic composite consisting of a ceramic preform with graded and continuously aligned open pores, infiltrated with epoxy resin. METHODS: The freeze casting technique was used to obtain the hierarchically structured architecture of the ceramic preforms. Optical and scanning electron microscopy (SEM) and differential thermal analysis and thermogravimetry (TG-DTA) were used to characterize the samples. Three point bending test and compression test were also performed. RESULTS: All analysis confirmed that the biomimetic composite was characterized by a multi-level hierarchical structure along the freezing direction. In the bottom layers close to the cooling plate (up to 2mm thick), a randomly packed ceramic with closed pores were formed, which resulted in incomplete infiltration with resin and resultant poor mechanical propertiesof the composite. Above 2mm, all ceramic samples showed an aligned structure with an increasing lamellae spacing (wavelength) and a decreasing wall thickness. Mechanical tests showed that the properties of the composites made from ceramic preforms above 2mm from cooling plate are similar to those of the dentin. SIGNIFICANCE: The fabrication processing reported in this work offers a viable route for the fabrication of biomimetic composites, which could be potentially used in a range of dental restorations to compete with the current dental composites and ceramics.

Electrospun biomimetic scaffold of hydroxyapatite/chitosan supports enhanced osteogenic differentiation of mMSCs.

Engaging functional biomaterial scaffolds to regulate stem cell differentiation has drawn a great deal of attention in the tissue engineering and regenerative medicine community. In this study, biomimetic composite nanofibrous scaffolds of hydroxyapatite/chitosan (HAp/CTS) were prepared to investigate their capacity for inducing murine mesenchymal stem cells (mMSCs) to differentiate into the osteogenic lineage, in the absence and presence of an osteogenic supplementation (i.e., ascorbic acid, ß-glycerol phosphate, and dexamethasone), respectively. Using electrospun chitosan (CTS) nanofibrous scaffolds as the control, cell morphology, growth, specific osteogenic genes expression, and quantified proteins secretion on the HAp/CTS scaffolds were sequentially examined and assessed. It appeared that the HAp/CTS scaffolds supported better attachment and proliferation of the mMSCs. Most noteworthy was that in the absence of the osteogenic supplementation, expression of osteogenic genes including collagen I (Col I), runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), and osteocalcin (OCN) were significantly upregulated in mMSCs cultured on the HAp/CTS nanofibrous scaffolds. Also increased secretion of the osteogenesis protein markers of alkaline phosphatase and collagen confirmed that the HAp/CTS nanofibrous scaffold markedly promoted the osteogenic commitment in the mMSCs. Moreover, the presence of osteogenic supplementation proved an enhanced efficacy of mMSC osteogenesis on the HAp/CTS nanofibrous scaffolds. Collectively, this study demonstrated that the biomimetic nanofibrous HAp/CTS scaffolds could support and enhance the adhesion, proliferation, and particularly osteogenic differentiation of the mMSCs. It also substantiated the potential of using biomimetic nanofibrous scaffolds of HAp/CTS for functional bone repair and regeneration applications.