OBJECTIVES: Calcium silicate (CSO) is modified to give it photothermal antibacterial properties. Its application potential in tooth mineralization and oral antibacterial is evaluated. METHODS: Based on defect-engineering modification strategy, a series of CSO-T samples (CSO-300, CSO-400, CSO-500, CSO-600) was obtained by introducing oxygen vacancy into CSO through thermal reduction using sodium borohydride. The samples were tested using scanning electron microscopy (SEM), X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet near-infrared absorption spectroscopy, and infrared thermography. The powder samples with the best photothermal performance and the most suitable material concentration (CSO-500, 500 μg/mL) were selected for subsequent experiments. High resolution transmission electron microscopy was used to analyze the microstructure and morphology of the sample, and MTT assay and Calcein AM/PI live/dead cell staining were used to evaluate the toxicity and compatibility of the sample to human oral keratinocytes. Escherichia coli and Staphylococcus aureus were selected for photothermal antibacterial experiments to evaluate their in vitro antibacterial performance. SEM, energy dispersive spectrometer, and micro Vickers hardness tester were used to evaluate the ability of materials to induce in vitro remineralization of detached teeth. RESULTS: Oxygen vacancies changed the crystal type and lattice spacing of CaSiO₃, broadened the light-absorption range, and gave it a good photothermal conversion ability in response to near infrared. Invitro experiments showed that the modified CaSiO₃ could promote the formation of hydroxyapatite on the tooth surface, thereby promoting the remineralization of teeth and improving the teeth hardness. Moreover, it had photothermal antibacterial properties and no cytotoxicity. CONCLUSIONS Defect-modified black calcium silicate has multiple functions, such as promoting tooth remineralization and photothermal bacteriostatic. When combined with the infrared luminescent toothbrush, it can simply and effectively treat tooth enamel erosion and oral bacteriostatic diseases caused by the excessive consumption of carbonated beverages and other daily bad living habits. This combination is expected to achieve the synergic treatment effect of tooth remineralization and oral bacteriostatic through daily cleaning is expected.
Calcium Compounds/pharmacology* ; Silicates/pharmacology* ; Humans ; Staphylococcus aureus/drug effects* ; Tooth Remineralization ; Escherichia coli/drug effects* ; Anti-Bacterial Agents/pharmacology* ; Keratinocytes/drug effects* ; Microscopy, Electron, Scanning

This study compared the biological changes of lipopolysaccharide (LPS)-treated dental pulp (DP) cells directly cultured on mineral trioxide aggregate (MTA) and calcium silicate (CS) cements. DP cells were treated with LPS for 24 h. Then, the LPS-treated DP cells were cultured on MTA or CS cements. Cell viability, cell death mechanism and interleukin (IL)-1β expressions were analysed. A one-way analysis of variance was used to evaluate the significance of the differences between the means. A significantly higher IL-1β expression (2.9-fold) was found for LPS-treated cells (P<0.05) compared with DP cells without LPS treatment at 24 h. Absorbance values of LPS-treated cells cultured on CS cement were higher than a tissue culture plate. A significant difference (P<0.05) in cell viability was observed between cells on CS and MTA cements 24 h after seeding. At 48 h, a high concentration of Si (5 mM) was released from MTA, which induced LPS-treated DP cell apoptosis. The present study demonstrates that CS cement is biocompatible with cultured LPS-treated DP cells. MTA stimulates inflammation in LPS-treated DP cells, which leads to greater IL-1β expression and apoptosis.
Calcium Compounds ; Dental Cements ; Dental Pulp ; drug effects ; metabolism ; Humans ; Inflammation ; chemically induced ; metabolism ; Interleukin-1beta ; metabolism ; Lipopolysaccharides ; pharmacology ; Silicates

OBJECTIVETo study the regulative action of mica monomer powder preparation on the chief and parietal cells as well as G and D cells in the gastric mucosa of the experimental atrophic gastritis (CAG) rats.

METHODSIntervention therapy was given to the experimental CAG rats at three different doses of mica monomer powder preparation to evaluate the changes of chief and parietal cells as well as G and D cells in the gastric mucosa and the histopathological changes of gastric mucosa.

RESULTSMica monomer powder preparation at three different doses could increase the amount of chief and parietal cells as well as G and D cells in gastric mucosa of the experimental CAG rats and alleviate and control the inflammation of gastric mucosa and the atrophy of gastric mucosa glands. Especially, better effects were shown in the mid and high dose groups.

CONCLUSIONMica has the pharmacological action of protecting the gastric mucosa, enhancing blood flow of the gastric mucosa, and consequently improving the inflammatory responses of the gastric mucosa. One of the mechanisms is associated with promoting the secretion of gastric acid and gastric pepsin and regulating the neuroendocrine mechanism including gut hormone secretion (gastrin and somatostatin) by increasing the number of chief and parietal cells as well as G and D cells.

Aluminum Silicates ; pharmacology ; Animals ; Cell Count ; Chief Cells, Gastric ; drug effects ; pathology ; Chronic Disease ; Gastric Mucosa ; drug effects ; pathology ; Gastrin-Secreting Cells ; drug effects ; pathology ; Gastritis, Atrophic ; pathology ; Inflammation ; Parietal Cells, Gastric ; drug effects ; pathology ; Powders ; Rats ; Rats, Sprague-Dawley ; Somatostatin-Secreting Cells ; drug effects ; pathology

OBJECTIVETo develop antibacterial coatings for orthopedic implants with a sustained release of drugs.

METHODSWollastonite coatings were deposited on the titanium substrates by an atmospheric plasma spray system. After soaking in weight percent of 5% AgNO(3) solution for 24 h, the wollastonite coatings loading silver were obtained. Gentamicin were loaded on the wollastonite coatings by collagen grafting process. The release rates of drugs from wollastonite coatings were investigated by the in vitro solution soaking test. One strain of S. aureus was used in zone of inhibition test to evaluate the antibacterial properties of drug loaded wollastonite coatings, and the cell culture test was used to evaluate their cytotoxicity.

RESULTSSilver and gentamicin loaded wollastonite coatings were successfully prepared. The release of silver ions from the silver loaded wollastonite coatings lasted 50 d in deionized water, effectively inhibiting the growth of S. aureus for 40 d. While an initial burst release of gentamicin was found during the in vitro solution soaking test. The gentamicin released from gentamicin loaded wollastonite coatings can inhibit the growth of S. aureus for 18 d. Both the two kinds of antibacterial wollastonite coatings showed no adverse effect on cellular adhesion, proliferation and alkaline phosphatase expression.

CONCLUSIONSCompared with gentamicin loaded wollastonite coatings, silver loaded wollastonite coatings may have more promising clinical applications due to the even and long-time antibacterial agent release.

Anti-Bacterial Agents ; pharmacology ; Calcium Compounds ; Cells, Cultured ; Coated Materials, Biocompatible ; pharmacology ; Gentamicins ; pharmacology ; Materials Testing ; Microbial Sensitivity Tests ; Osteoblasts ; cytology ; drug effects ; Silicates ; Silver ; pharmacology

OBJECTIVETo research the regulative effect of mica monomer granule preparation on the expression of gene associated with cancer in gastric mucosa tissue of experimental chronic atrophic gastritis (CAG) rats.

METHODTo treat experimental CAG rats using mica monomer granule preparation with three different dosage-high, moderate and low level respectively. To observe the expression changes of mutant antioncogene-p53 gene-protein, oncogene p21, antioncogene p16 and anti-apoptosis gene bcl-2 in gastric mucosa of CAG rats by two-step ways of EnVision system in immunohistochemical method.

RESULTThere was the tendency that mica monomer granule preparation with three different dosage could decrease the expression of p53 as well as p21, and mica had the obvious regulative effects on deletion of p16 and high-expression of bcl-2. It could also alleviate the inflammation of gastric mucosa and promote the regeneration of gland.

CONCLUSIONThe treatment and reversion action of mica on chronic atrophic gastritis is probably related with the regulative effect on the expression of gene associated with cancer.

Aluminum Silicates ; administration & dosage ; pharmacology ; Animals ; Cyclin-Dependent Kinase Inhibitor p16 ; metabolism ; Dose-Response Relationship, Drug ; Gastric Mucosa ; metabolism ; pathology ; Gastritis, Atrophic ; metabolism ; pathology ; Materia Medica ; administration & dosage ; pharmacology ; Oncogene Protein p21(ras) ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tumor Suppressor Protein p53 ; metabolism ; Tumor Suppressor Proteins ; metabolism

OBJECTIVETo examine the efficacy of Muscovite on acetic acid-induced ulcerative colitis in rats, and to research the mechanisms of intestinal mucosal protection.

METHODUlcerative colitis was induced in rats by intracolonic injection of 2 mL of 7% acetic acid. Rats were treated with three different doses of the Muscovite and SASP at random by intracolonic injecion, the normal saline was considered as control group. The rats were sacrificed and the colons were excised and opened longitudinally. Under a dissecting microscope, gross findings were observed and scored. MPO activity was assayed by spectrophotometry in colonic mucosa.

RESULTGross finding showed that multiple ulcer with diameter more than 1 cm, surrounded with erosion, erythematous and edema in the proximal colon in ulcerative coltis. The colon from Muscovite treatment group were histopatholgically normal, with slight erosion, erythematous and edema. The colon in SASP group had small ulceration and severe erosion and edema. The score of gloss change were significant lower in Muscovite groups than that in normal saline group (P < 0.01). There were necrosis and exfoliation of mucosa, multiple cystic dilation of mucosa gland, and large number of and inflammation attenuated in Muscovite groups. There nerutrophils and vessel infiltration in ulcerative colitis. The ulceration disappeared were erosion in mucosa and inflammatory cell infiltrating into submucosa in SASP group. Compared with normal saline group, the pathological scale were significant decreased in Muscovite and SASP groups (P < 0.05). The MPO activity was significant increased in colitis tissue compared with normal group (P < 0.001). After administrating with Muscovite or SASP, the level of MPO were significant decreased (P < 0.01).

CONCLUSIONMuscovite has the effect of mucosal protection by attenuating the inflammation of colonic mucosa and decreasing the activity of MPO.

Acetic Acid ; Aluminum Silicates ; pharmacology ; Animals ; Colitis, Ulcerative ; chemically induced ; enzymology ; pathology ; Colon ; enzymology ; pathology ; Intestinal Mucosa ; enzymology ; pathology ; Male ; Materia Medica ; pharmacology ; Peroxidase ; metabolism ; Protective Agents ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo explore the effect of muscovite on the quality of gastric ulcer healing.

METHODGastric ulcers were produced in male rats by serosal application of acetic acid. Rats were gavaged for 14 days with saline, omeprazole and muscovite starting 3 days after ulcer induction. Then the tissue and blood samples were obtained and measured.

RESULTIn the muscovite group, restored mucosa thickness increased, cystically dilated glands decreased, microvessels in connective tissue increased, the secretion of mucus, hexosamine, PGE2, EGF, bFGF were enhanced, and the express of EGFR was stronger.

CONCLUSIONMuscovite can promote the gastric ulcer healing and improve the quality of gastric ulcer healing.

Aluminum Silicates ; pharmacology ; Animals ; Dinoprostone ; blood ; Fibroblast Growth Factor 2 ; metabolism ; Gastric Mucosa ; pathology ; physiopathology ; Hexosamines ; metabolism ; Male ; Materia Medica ; pharmacology ; Mucus ; secretion ; Rats ; Rats, Wistar ; Receptor, Epidermal Growth Factor ; metabolism ; Stomach Ulcer ; chemically induced ; pathology ; physiopathology

OBJECTIVETo explore the mechanisms of muscovite gastric mucosal protective effect.

METHODRat model of chronic gastritis were used. After gastric mucosal injury was induced, the rats were divided into 6 groups and were treated with different drugs. 2 weeks later, the tissue and blood samples were obtained and measured.

RESULTThe general conditions, the observations under macroscopy, microscope and electron microscope of the middle and high dose of muscovite groups resembled those of the normal group. Their PH levels were higher than those of the model group, and the rates of intestinal metaplasia were lower, but the PGE2 level of the middle dose of muscovite group was the highest.

CONCLUSIONMuscovite can be adsorbed on the surface of the gastric mucosa. It has gastric mucosal protective effect by improving excretion of mucus and synthesis of PGE2 in gastric mucosa, restraining gastric acid, reversing of intestinal metaplasia and decreasing inflammation cells.

Aluminum Compounds ; pharmacology ; Animals ; Dinoprostone ; blood ; Gastric Juice ; chemistry ; Gastric Mucosa ; pathology ; ultrastructure ; Gastritis ; blood ; chemically induced ; pathology ; Hydrogen-Ion Concentration ; Materia Medica ; pharmacology ; Microscopy, Electron, Scanning ; Potassium Compounds ; pharmacology ; Protective Agents ; pharmacology ; Rats ; Rats, Wistar ; Silicates ; pharmacology ; Sodium Salicylate

OBJECTIVETo study regulative action of mica monomer granule preparation on gastrin (GAS), somatostatin (SS) and G cells as well as D cells of gastric mucosa in experimental chronic atrophic gastritis (CAG) rat.

METHODCAG rats were treated with mica monomer granule preparation with three different dosages--high, moderate and low level respectively. Changes of blood serum GAS, blood plasma SS and G cells as well as D cells of gastric mucosa in CAG rats were observed and detected with ELISA method, RIA method and immunocytochemistry method.

RESULTMica monomer granule of three different dosages could increase the quantity of G cells as well as D cells of gastric mucosa and the concentration of blood serum GAS and decrease the content of blood plasma SS in CAG rat at different level respectively. It was more effective in high and moderate dosage groups.

CONCLUSIONMica has the pharmacological action of protecting gastric mucosa, promoting the palingenesis of gastric gland and enhancing blood stream of gastric mucosa consequently to abate the inflammation reaction of gastric mucosa. Its effective mechanism is associated with the neuroendocrine regulative mechanism of promoting the secretion of gastric acid and gastric pepsin by increasing the amount of G cells as well as D cells and the concentration of blood serum GAS, and reducing inhibiting action on GAS secretion and enhancing the secretion of GAS by decreasing the content of SS.

Aluminum Silicates ; administration & dosage ; pharmacology ; Animals ; Dose-Response Relationship, Drug ; Gastric Mucosa ; pathology ; Gastrin-Secreting Cells ; drug effects ; Gastrins ; blood ; Gastritis, Atrophic ; blood ; pathology ; Materia Medica ; administration & dosage ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Somatostatin ; blood ; Somatostatin-Secreting Cells ; drug effects