Poly(N-isopropylacrylamide) based smart nanofibrous scaffolds for use as on-demand delivery systems for oral and dental tissue regeneration.

Stimuli-responsive domains capable of releasing loaded molecules, "on-demand," have garnered increasing attention due to their enhanced delivery, precision targeting, and decreased adverse effects. The development of an on-demand delivery system that can be easily triggered by dental clinicians might have major roles in dental and oral tissue engineering. A series of random graft poly(NIPAm-co-HEMA-Lactate) copolymers were synthesized using 95:5, 85:5, 60:40, and 40:60 ratios of thermosensitive NIPAm and HEMA-poly lactate respectively then electrospun to produce nanofibrous scaffolds loaded with bovine serum albumin (BSA). Cumulative BSA release was assessed at 25C and 37°C. To appraise the use of scaffolds as on-demand delivery systems, they were subjected to thermal changes in the form cooling and warming cycles during which BSA release was monitored. To confirm the triggered releasing ability of the synthesized scaffolds, the copolymer made with 60% NIPAm was selected, based on the results of the release tests, and loaded with bone morphogenetic protein-2 (BMP-2). The loaded scaffolds were placed with mesenchymal-like stem cells (iMSCs) derived from induced pluripotent stem cells (iPSCs), and subjected to temperature alterations. Then, the osteogenic differentiation of iMSCs, which might have resulted from the released protein, was evaluated after 10 days by analyzing runt-related transcription factor 2 (RUNX-2) osteogenic gene expression by the cells using real-time quantitative polymerase chain reaction (qRT-PCR). BSA release profiles showed a burst release at the beginning followed by a more linear pattern at 25°C, and a much slower release at 37°C. The release also decreased when the PNIPAm content decreased in the scaffolds. Thermal triggering led to a step-like release pattern in which the highest release was reported 30 min through the warming cycles. The iMSCs cultivated with scaffolds loaded with BMP-2 and exposed to temperature alteration showed significantly higher RUNX-2 gene expression than cells in the other experimental groups. The synthesized scaffolds are thermo-responsive and could be triggered to deliver biological biomolecules to be used in oral and dental tissue engineering. Thermal stimuli could be simulated by dental clinicians using simple means of cold therapy, for example, cold packs in intraoral accessible sites for specified times.

Biomonitoring of a Nile Delta Lake using benthic foraminifera.

Lake Edku, one of the northern Nile Delta lakes, is a shallow brackish coastal lake subjected to domestic and agricultural effluents via two main drains, El-Khairy and Barsik, in addition to the discharge water of hundreds of fish farms. This study measures the responses of the benthic foraminiferal assemblage to the environmental stressors in Lake Edku. Grain size, organic carbon, and seven potentially toxic elements (Cu, Pb, Zn, Cd, Cr, Ni, and As) were determined in nine short cores (25-35 cm depth). The lake was characterized by vertical increase in mud, organic matter, and concentrations of all metals, particularly in the eastern basin at the vicinity of the drain discharges. This trend coincides with a general decrease in species diversity and increase in deformed specimens. The foraminiferal assemblage was dominated by Ammonia tepida (Cushman), a pollution-tolerant and euryhaline species. This study demonstrates that benthic foraminiferal assemblages provide a reliable pollution proxy in the brackish environments of Nile Delta that can be used in the periodical monitoring of the coastal lakes.

GC/MS Profiling and Ex Vivo Antibacterial Activity of Salvadora persica (Siwak) against Enterococcus faecalis as Intracanal Medicament.

INTRODUCTION: Salvadora persica L. (S. persica, Siwak) has been used for many centuries as oral hygiene tools, particularly in Saudi Arabia. This study aimed to assess the effectiveness of S. persica petroleum ether extract (SPE) as an intracanal bactericidal for endodontic treatment against Enterococcus faecalis. Calcium hydroxide Ca(OH)2 gold standard intracanal medicament was used for comparison. METHODS: The gas chromatography mass spectrometry (GC/MS) analysis was carried out to identify the components of SPE. First, the consistency of SPE was accomplished according to ANSI/ADA specification no 57. Forty-five single-rooted mandibular premolars were infected with that of E. faecalis suspension. Colony-forming units (CFU) were counted before the medicaments' application (CFU-1) and after seven days of their applications (CFU-2). Group I: SPE, Group II: positive control Ca(OH)2, and Group III: saline solution negative control. The microdilution method was applied to determine minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of SPE. RESULTS: Thirty-two compounds were identified (89.09%), with main components of benzyl isothiocyanate (BITC) (33.32%) and steroids (34%). CFU before and after using SPE and Ca(OH)2 recorded a statistically significant reduction in bacterial count (P=0.006) and (P=0.01), respectively. There was an insignificant difference between CFU after using SPE and Ca(OH)2 (P=0.210). On the contrary, comparing both medicaments with the negative control saline group resulted in significant differences, (P=0.001) and (P=0.007), respectively. Moreover, the equality of minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) of SPE is recorded. CONCLUSION: This finding could be referred to the high content of bactericidal BITC in synergism with other antimicrobial components, representing 70.71% of SPE. Thus, SPE is a good candidate as an intracanal medicament, which warrants further investigation.

HPLC/MSn Profiling and Healing Activity of a Muco-Adhesive Formula of Salvadora persica against Acetic Acid-Induced Oral Ulcer in Rats.

Salvadora persica L. (S. persica, Siwak) is an ethnic plant that is widely used for improving oral hygiene. This study aimed to provide a phytochemical profiling of S. persica ethyl acetate fraction (SPEAF) and to evaluate the healing activity of a muco-adhesive formula of the fraction against acetic acid-induced oral ulcers in rats. HPLC-ESI-QTOF-MS-MS analysis of SPEAF resulted in the tentative identification of 56 metabolites containing fatty acids (23%), urea derivatives (10.5%) and sulphur compounds (10%), in addition to several amides, polyphenols and organic acids (6.5%, 5% and 2%, respectively). For the first time, 19 compounds were identified from S. persica. In vitro and in vivo experiments indicated that the extract is non-toxic. SPEAF exhibited superior healing activities compared to both the negative and positive control groups on days 7 and 14 of tongue ulcer induction. This was confirmed by histopathological examinations of haematoxylin and eosin-stained (H&E) and Masson's trichrome-stained tongue sections. Moreover, SPEAF showed potent anti-inflammatory activities, as evidenced by the inhibited expression of interleukin-6 (IL-6) and tumour necrosis alpha (TNF-α). Moreover, SPEAF exhibited potent antioxidant activity, as it prevented malondialdehyde (MDA) accumulation, reduced glutathione (GSH) depletion and superoxide dismutase (SOD) exhaustion. SPEAF significantly enhanced hydroxyproline tongue content and upregulated collagen type I alpha 1 (Col1A1) mRNA expression. SPEAF also improved angiogenesis, as shown by the increased mRNA expression of the angiopoietin-1 (Ang-1). In conclusion, S. persica has a wide range of secondary metabolites and ameliorates acetic acid-induced tongue ulcers in rats. This can be attributed, at least partly, to its anti-inflammatory, antioxidant, procollagen and angiogenic activities. These findings provide support and validity for the use of S. persica as a traditional and conventional treatment for oral disorders.

Effect of anodization and alkali-heat treatment on the bioactivity of titanium implant material (an in vitro study).

OBJECTIVE: This study was aimed to assess the effect of anodized and alkali-heat surface treatment on the bioactivity of titanium alloy (Ti-6Al-4V) after immersion in Hank's solution for 7 days. MATERIALS AND METHODS: Fifteen titanium alloy samples were used in this study. The samples were divided into three groups (five for each), five samples were anodized in 1M H3PO4 at constant voltage value of 20 v and another five samples were alkali-treated in 5 M NaOH solution for 25 min at temperature 60°C followed by heat treatment at 600°C for 1 h. All samples were then immersed in Hank's solution for 7 days to assess the effect of surface modifications on the bioactivity of titanium alloy. The different treated surfaces and control one were characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transformation infra-red spectroscopy. Statistical analysis was performed with PASW Statistics 18.0(®) (Predictive Analytics Software). RESULTS: Anodization of Ti-alloy samples (Group B) led to the formation of bioactive titanium oxide anatase phase and PO4 (3-) group on the surface. The alkali-heat treatment of titanium alloy samples (Group C) leads to the formation of bioactive titania hydrogel and supplied sodium ions. The reaction between the Ti sample and NaOH alkaline solution resulted in the formation of a layer of amorphous sodium titania on the Ti surface, and this layer can induce apatite deposition. CONCLUSIONS: The surface roughness and surface chemistry had an excellent ability to induce bioactivity of titanium alloy. The anodization in H3PO4 produced anatase titanium oxide on the surface with phosphate originated from electrolytes changed the surface topography and allowed formation of calcium-phosphate.

The effect of plasma surface treatment on the bioactivity of titanium implant materials (in vitro).

BACKGROUND: The surface of an implantable biomaterial plays a very important role in determining the biocompatibility, osteoinduction, and osteointegration of implants because it is in intimate contact with the host bone and soft tissues. OBJECTIVE: This study was aimed to assess the effect of plasma surface treatment on the bioactivity of titanium alloy (Ti-6Al-4V). MATERIALS AND METHODS: Fifteen titanium alloy samples were used in this study. The samples were divided into three groups (with five samples in each group). Five samples were kept untreated and served as control (group A). Another five plasma samples were sprayed for nitrogen ion implantation on their surfaces (group B) and the last five samples were pre-etched with acid before plasma treatment (group C). All the investigated samples were immersed for 7 days in Hank's balanced salt solution (HBSS) which was used as a simulating body fluid (SBF) at pH 7.4 and 37°C. HBSS was renewed every 3 days. The different surfaces were characterized by X-ray diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDXA), and Fourier Transformation Infrared Spectroscopy (FTIR). RESULTS: Nitriding of Ti-alloy samples via plasma nitrogen ion implantation increased the bioactivity of titanium. Moreover, the surface topography affected the chemical structure of the formed apatite. Increasing the surface roughness enhanced the bioactivity of the implant material. CONCLUSIONS: Nitridation can be exploited as an effective way to promote the formation of bone-like material on the implant surface.

Chemical and biological evaluation of Egyptian Nile Tilapia (Oreochromis niloticas) fish scale collagen.

Collagen is considered to be one of the most useful biomaterials with different medical applications. However, collagen properties differ from one source to another. The aim of this study was to extract, purify, characterize and perform preliminary biological evaluation of type I collagen from scales of Egyptian Nile Tilapia. Pepsin-solubilized collagen (PSC) was successfully prepared from Nile Tilapia fish scale waste. Lyophilized collagen was dissolved in dilute HCl to form acidic collagen solutions (ACS) which was neutralized to form gel. To confirm the biocompatibility of the produced gel, baby hamster kidney (BHK-21) fibroblast cells were seeded onto a 3D collagen gel (0.3% and 0.5%, w/v). The results of an SDS-PAGE test showed that the extracted collagens were type I collagen, with α chain composition of (α1)2α2. Thermal analysis showed that the denaturation temperature was 32 °C. X-ray diffraction (XRD) analysis and Fourier-transform infrared spectra (FTIR) showed that the extracted collagen had a triple helix structure. Active proliferation of BHK-21 cells with no signs of toxicity was evident with both collagen gel concentrations tested. The results show that Nile Tilapia scales can be an effective source of collagen extraction that could be used as a potential biomaterial in biomedical applications.

Treatment of wastewater containing arsenic using Rhazya stricta as a new adsorbent.

The effective removal of heavy metals from aqueous wastes is among the most important issues for many industrialized countries. Removal of arsenic (As) from aqueous solutions was studied using Rhazia stricta biomass. The batch experiments are carried out to investigate the effect of the significant process parameters such as pH, contact time, solute concentration and adsorbent dose. The optimum pH required for maximum adsorption was found to be 5. The equilibrium data for the adsorption of As(V) on R. stricta are tested with various adsorption isotherm models such as Langmuir, Freundlich, Tempkin and Generalized equation. Results indicate the following order to fit the isotherm: Langmuir (1 and 2) > Tempkin > Generalized form > Freundlich. A comparison of two kinetic models showed that our data fitted well to the Elovich model.

Heavy metal biomonitoring and phytoremediation potentialities of aquatic macrophytes in River Nile.

The concentrations of Cd, Cu, Pb, and Zn in sediments, water, and different plant organs of six aquatic vascular plant species, Ceratophyllum demersum L. Echinochloa pyramidalis (Lam.) Hitchc. & Chase; Eichhornia crassipes (Mart.) Solms-Laub; Myriophyllum spicatum L.; Phragmites australis (Cav.) Trin. ex Steud; and Typha domingensis (Pers.) Poir. ex Steud, growing naturally in the Nile system (Sohag Governorate), were investigated. The aim was to define which species and which plant organs exhibit the greatest accumulation and evaluate whether these species could be usefully employed in biomonitoring and phytoremediation programs. The recorded metals in water samples were above the standard levels of both US Environmental Protection Agency and Egyptian Environmental Affairs Agency except for Pb. The concentrations of heavy metals in water, sediments, and plants possess the same trend: Zn > Cu > Pb > Cd which reflects the biomonitoring potentialities of the investigated plant species. Generally, the variation of heavy element concentrations in water and sediments in relation to site and season, as assessed by two-way repeated measured ANOVA, was significant (p < 0.05). However, insignificant variations were observed in the concentrations of Pb and Cd in sediments in relation to season and of Cu and Zn in relation to site. Results also showed that the selectivity of the heavy elements for the investigated plants varied significantly (p < 0.05) with species variation. The accumulation capability of the investigated species could be arranged according to this pattern: C. demersum > E. crassipes > M. spicatum > E. pyramidalis > T. domingensis > P. australis. On the basis of the element concentrations, roots of all the studied species contain higher concentrations of Cu and Zn than shoots while leaves usually acquire the highest concentrations of Pb. Cd concentrations among different plant organs are comparable except in M. spicatum where the highest Cd concentrations were recorded in the leaves. Our results also demonstrated that all the studied species can accumulate more than 1,450-fold the concentration of the investigated heavy elements in water rendering them of interest for use in phytoremediation studies of polluted waters. Given the absence of systematic water quality monitoring, heavy elements in plants, rather than sediments, provide a cost-effective means for assessing heavy element accumulation in aquatic systems during plant organ lifespan.

3D cell culture opens new dimensions in cell-based assays.

3D cell culture technologies have revolutionized our understanding of cellular behavior, both in culture and in vivo, but adoption by cell-based screening groups has been slow owing to problems of consistency, scale and cost. The evolving field of high content screening technologies will, however, require a rethinking of 3D cell culture adoption to ensure the next generation of cells provide relevant in vivo-like data. Three current technologies are presented in this review: membranes, sponges/gels and microcarriers. A short history of these technologies and unique research applications are discussed. Also, the technologies are evaluated for usefulness in modern automated cell-based screening equipment.

Metal pollution records in core sediments of some Red Sea coastal areas, Kingdom of Saudi Arabia.

In the last three decades, the industrial and human activities in the coastal area of Saudi Arabia have increased dramatically and resulted in the continuous invasion of different types of pollutants including heavy metals. Seven sediment cores were collected from three major industrialized areas; Jeddah, Rabigh and Yanbu, along the coast of Saudi Arabia to determine the spatial and temporal distribution of metals and to assess the magnitude of pollution and their potential biological effects. Sediments were analyzed for texture, calcium carbonate contents, organic matter and metals (Al, Fe, Mn, Cd, Cr, Cu, Ni, Pb and Zn). Some metals like, Cr, Mn, Ni and Zn, were enriched in the upper 15 cm of core samples (recent deposition of sediments). Cadmium concentrations showed high fluctuations with depth and reverse pattern to that for Al, Fe and Mn which indicated land based sources of this element to the studied areas. Elevated concentrations of lead were recorded in the bottom layers of cores in Jeddah that indicated the most dramatic increase in usage of gasoline in early 1970s. The calculated contamination factors (CF's) were found in the following sequences: Cd > Pb > Ni > Cu > Zn > Cr > Mn for all studied areas. Results of Pollution Load Index (PLI) revealed that Jeddah is the most polluted area, followed by Rabigh while Yanbu is the least contaminated area. Except for Ni, the concentrations of most metals in the majority of sediment samples were believed to be safe for living organisms. As no data were available on the concentration of metals in core sediments in the coastal area of Saudi Arabia, the results of this study would serve as a baseline against which future anthropogenic effects can be assessed.

Hydroxyapatite-electroplated cp-titanium implant and its bone integration potentiality: an in vivo study.

PURPOSE: This study was designed to precipitate hydroxyapatite coating on the surface of commercially pure titanium (cpTi) implants using an electroplating technique. After characterization of the hydroxyapatite coating, the bone-implant interface and bone integration of both cpTi and hydroxyapatite-coated implants were assessed. MATERIALS: Twenty implants were divided equally into 2 main groups (n = 10). Ten cpTi implants were utilized as received, while the others were hydroxyapatite coated and then sterilized. The implants of both groups were inserted in the tibiae of New Zealand rabbits. The purity and crystallinity of the hydroxyapatite coat were characterized using x-ray diffraction. A scanning electron microscope examined the grain morphology. Profilometer evaluated the surface texture before and after sterilization. Histological examination using a scanning electron microscope was performed to qualify osseointegration of the regenerated bone and measure the gap distance at the bone-implant interface. RESULTS: Pure crystalline hydroxyapatite precipitate of thickness (range 69-78 microm) and rough surface (2.7 +/- 0.2 microm) compared to smooth cpTi (1.3 +/- 0.5 microm). The gamma-radiation sterilization resulted in finer grains and insignificant smoother surface. Histological examination of the cpTi implant exhibited less bone regeneration with few and less dense bone trabeculae, and gap distance was significantly high (1.29 +/- 0.51 microm). Meanwhile, the hydroxyapatite-coated implant showed a recognizable amount of bone regeneration with more and denser bone trabeculae, and gap distance ranged from 0 to 1.32 microm. CONCLUSIONS: The employed technique provided a thin and uniform pure crystalline hydroxyapatite coating. The characterization of the precipitated film is promising for clinically successful long-term bone fixation.

Activation in vagal afferents and central autonomic pathways: early responses to intestinal infection with Campylobacter jejuni.

Abundant evidence now supports the idea that multiple pathways or mechanisms underlie communication from the immune system to the brain. The presence of a variety of mechanisms suggests that they may each contribute something different to immunosensory signaling. For instance, brain mediated immune signal transduction is dependent upon the presence of circulating mediators whereas peripheral sensory nerves are more likely to be important early on in an infection, prior to elevation of circulating cytokines, or in local infections within the terminal fields of these nerves. To test the hypothesis that local infection in the gut activates vagal sensory neurons, we assessed expression of the neuronal activation marker c-Fos in neurons in the vagal sensory ganglia and in the primary sensory relay nucleus for the vagus, the nucleus of the solitary tract (nTS) in mice treated orally either with saline or live Campylobacter jejuni (C. jejuni). Male CF1 mice were inoculated orally with either C. jejuni or saline, and c-Fos expression in the vagal sensory neurons and brain 4-12 h later was assessed via immunohistochemistry. Oral inoculation with C. jejuni led to a significant increase in c-Fos expression in neurons bilaterally in the vagal ganglia, in the absence of elevated levels of circulating pro-inflammatory cytokines. C. jejuni treatment activated neurons in the nTS, as well as in brain regions associated with primary viscerosensory pathways and the central autonomic network. These findings provide evidence that peripheral sensory neurons contribute an early signal to the brain regarding potential pathogens.

Reversible inactivation of the dorsal vagal complex blocks lipopolysaccharide-induced social withdrawal and c-Fos expression in central autonomic nuclei.

Peripheral administration of lipopolysaccharide (LPS), a potent activator of the immune system, induces symptoms of behavioral depression, such as social withdrawal, concommitant with increases in c-Fos expression in central autonomic network nuclei. Previous studies implicated vagal visceral sensory nerves in transduction of immune-related signals relevant to for the induction of social withdrawal, a symptom of behavioral depression. Vagal sensory nerves terminate in the dorsal vagal complex (DVC) of the brainstem, a region that functions to integrate visceral signals and may also play a role in modulating arousal and affect. The objective of the current study was to determine whether the DVC contributes to immunosensory pathways driving symptoms of social withdrawal associated with LPS-induced behavioral depression, using a reversible lesion technique to temporarily inactivate the DVC. To assess the effects of DVC inactivation on LPS-induced social withdrawal and the subsequent changes in brain activation, we used behavioral assessment of social withdrawal, and analyzed c-Fos expression, a marker of neuronal activation, in the central nucleus of the amygdala (CEA), bed nucleus of the stria terminalis (BST), hypothalamic paraventricular nucleus (PVN), and ventromendial preoptic area (VMPO). Two hours following intraperitoneal LPS injection, there was a significant increase in c-Fos immunoreactivity in forebrain regions in animals treated with LPS. DVC inactivation completely blocked LPS-induced social withdrawal and dramatically reduced LPS-induced Fos expression in all four forebrain regions assessed. Collectively, these findings support the idea that the DVC acts as an immune-behavior interface between the peripheral stimuli and brain areas involved in modulating social behavior.