Drug delivery systems for oral disease applications

Abstract There are many restrictions on topical medications for the oral cavity. Various factors affect the topical application of drugs in the oral cavity, an open and complex environment. The complex physical and chemical environment of the oral cavity, such as saliva and food, will influence the effect of free drugs. Therefore, drug delivery systems have served as supporting structures or as carriers loading active ingredients, such as antimicrobial agents and growth factors (GFs), to promote antibacterial properties, tissue regeneration, and engineering for drug diffusion. These drug delivery systems are considered in the prevention and treatment of dental caries, periodontal disease, periapical disease, the delivery of anesthetic drugs, etc. These carrier materials are designed in different ways for clinical application, including nanoparticles, hydrogels, nanofibers, films, and scaffolds. This review aimed to summarize the advantages and disadvantages of different carrier materials. We discuss synthesis methods and their application scope to provide new perspectives for the development and preparation of more favorable and effective local oral drug delivery systems.

Regulation mechanism of rnc gene on Streptococcus mutans environmental tolerance and its mechanism / 口腔疾病防治

Objective @#To study the changes of acid resistance, oxidation resistance and high osmotic pressure resistance of Streptococcus mutans after knockout of rnc gene and its possible regulatory mechanism.@*Methods@#Through PCR ligation mutagenesis, an rnc knockout mutant (Smurnc) was constructed. Acid tolerance, oxidation tolerance and high osmotic pressure tolerance were compared between Smurnc and the wild strain respectively. Real-time RT-PCR was used to verify the changes in expression of stress tolerance related genes at the transcriptional level.@*Results @#When rnc gene was knocked out, the acid tolerance (χ2=13.464, P=0.001) and oxidation tolerance (χ2=4.505, P=0.048) of Streptococcus mutans was significantly decreased, but the high osmotic pressure tolerance was significantly increased (χ2=11.971, P=0.001). Expression of stress tolerance related genes luxS and ropA (0.64 and 0.51 times expression of the wild strain) had been significantly downregulated (P<0.001). Expression of htrA and brpA (1.56 and 1.80 times expression of the wild strain) had been significantly upregulated (P<0.001).@*Conclusion @#The deletion of rnc gene affects the expression of the environmental tolerance related genes of Streptococcus mutans, which reduces its acid resistance and oxidation resistance, and enhances its tolerance to hypertonic pressure.

Exopolysaccharide dispelled by calcium hydroxide with volatile vehicles related to bactericidal effect for root canal medication

ABSTRACT Objective: Enterococcus faecalis is the dominant microbial species responsible for persistent apical periodontitis with ability to deeply penetrate into the dentin. Exopolysaccharides (EPS) contribute to the pathogenicity and antibiotic resistance of E. faecalis. Our aim was to investigate the antimicrobial activity of calcium hydroxide (CH), camphorated parachlorophenol (CMCP), and chlorhexidine (CHX) against E. faecalis in dentinal tubules. Material and Methods: Decoronated single-canal human teeth and semicylindrical dentin blocks were incubated with E. faecalis for 3 weeks. Samples were randomly assigned to six medication groups for 1 week (n=10 per group): CH + 40% glycerin-water solution (1:1, wt/vol); CMCP; 2% CHX; CH + CMCP (1:1, wt/vol); CH + CMCP (2:3, wt/vol); and saline. Bacterial samples were collected and assayed for colony-forming units. After dentin blocks were split longitudinally, confocal laser scanning microscopy was used to assess the proportion of viable bacteria and EPS production in dentin. Results: CMCP exhibited the best antimicrobial activity, while CH was the least sensitive against E. faecalis (p<0.05). CHX showed similar antimicrobial properties to CH + CMCP (1:1, wt/vol) (p>0.05). CH combined with CMCP inhibited EPS synthesis by E. faecalis, which sensitized biofilms to antibacterial substances. Moreover, increasing concentrations of CMCP decreased EPS matrix formation, which effectively sensitized biofilms to disinfection agents. Conclusion: The EPS matrix dispelled by CH paste with CMCP may be related to its bactericidal effect; the visualization and analysis of EPS formation and microbial colonization in dentin may be a useful approach to verify medicaments for antimicrobial therapy.

Value of CT angiography in reducing the risk of hemorrhage associated with mini-percutaneous nephrolithotomy

ABSTRACTPurpose:To evaluate the clinical value of computed tomography angiography (CTA) in reducing the risk of hemorrhage associated with mini-percutaneous nephrolithotomy (PCNL).Materials and Methods:A total of 158 patients with renal or ureter stones who had undergone mini-percutaneous nephrolithotomy were retrospectively enrolled into this study from May of 2011 to April of 2014. Group 1 (65 patients) underwent computed tomography angiography, and Group 2 (93 patients) underwent non-contrast CT. The clinical characteristics of the patients and hemorrhagic complications were recorded. The hematologic complications (transfusion rate, and preoperative and postoperative hemoglobin values) were assessed.Results:There were no statistically significant differences in age, body mass index(BMI), stone diameter, operative time, stone-free rate, and hospital stay between the 2 groups. In group 2, 1 patient (1.1%) developed a renal arteriovenous fistula and was treated with embolus therapy. In addition, Group 2 showed significantly drop in hemoglobin (3.6 g/dL vs. 2.4 g/dL, respectively; P <0.001) and more transfusions (9.7% vs. 1.5%, respectively; P <0.05) compared with Group 1.Conclusion:The study showed that patients who underwent computed tomography angiography prior to percutaneous nephrolithotomy had lower drop of hemoglobin and needed less transfusions. These findings may suggest that the use of computed tomography angiography may reduce the risk of bleeding during percutaneous nephrolithotomy.

Evaluation and new classification of alveolar bone dehiscences using cone-beam computed tomography in vivo / Evaluación y nueva clasificación de las dehicencias del hueso alveolar mediante tomografía computadorizada de haz cónico in vivo

Alveolar bone dehiscences, which were "V" shaped defects related the margin of the alveolar bone, were common findings in different populations and decreased bony support of teeth. It was difficult to detect dehiscence during direct clinical examination. All of the previous studies on the prevalence of dehiscences were based on dry human skulls. In the current article, we evaluated the prevalence of dehiscences occurring naturally in a Chinese subpopulation, and prepared a classification of dehiscences using cone-beam computed tomography (CBCT). The high prevalence rate of dehiscences and different characteristics of each category suggest that it would be helpful for clinicians who perform periodontal surgery, endodontic surgery, implant surgery or orthodontic treatment to understand which teeth are most often associated with such bony defects, and to consider the effect of severe dehiscences on their diagnosis and treatment plan.

Las dehiscencias óseas alveolares, con forma de "V" en el margen del hueso alveolar, son hallazgos comunes en diferentes poblaciones y provocan una disminución del soporte óseo de los dientes. La dehiscencia fue difícil de identificar durante la exploración clínica directa. Todos los estudios anteriores sobre la prevalencia de dehiscencia se basaron en cráneos humanos secos. En el presente artículo, se evaluó la prevalencia de dehiscencia natural ocurrido en una subpoblación de China. Realizamos una clasificación de las dehiscencias mediante tomografía computarizada cone-beam (TCCB). La alta prevalencia de dehiscencias y las diferentes características de cada categoría sugieren que esta clasificación sería de gran ayuda para los médicos que realizan cirugía periodontal, endodóntica, cirugía de implantes o tratamiento de ortodoncia, permitiendo informar sobre que dientes están más frecuentemente asociados con tales defectos óseos, y poder considerar los efectos severos de las dehiscencias severas en el diagnóstico y el plan de tratamiento.

Lingual radicular rift valley in a mandibular right first premolar root: report of a rare case and review of the literature / Surco radicular lingual en la raíces del primer premolar mandibular derecho: reporte de un raro caso y revisión de la literatura

Irregular root configurations which often challenge the requirements of successful root canal treatments are always misleading doctors to incorrect clinical judgments and treatment planning. In this article we describe a rare case of CBCT C-shaped mandibular premolar with a huge area of invagination measuring 6 mm ´ 3 mm, which we termed a "radicular rift valley" from a 76-year-old man. Considering the complex process of differential diagnosis, the overall status of disease condition and the will of the patient we proposed five treatment plans and finally conservatively chose plan B composed of both RCT and periapical scaling. A related literature review is also added into this article to describe the whole situation of root invagination, to stress the importance of the vigilance of diagnosis and to provide reference views for future similar diseases.

Las configuraciones radiculares irregulares que a menudo desafían las exigencias de un tratamiento de canal radicular exitoso, son siempre engañosas llevando al especialista a juicios clínicos y planificación de tratamientos erróneos. En este artículo se describe, en un hombre de 76 años de edad, un raro caso de un premolar mandibular que mediante CBCT se observa la forma de C con un área enorme de invaginación midiendo 6 mm x 3 mm, lo que hemos denominado un "Rift valley radicular ". Teniendo en cuenta el complejo proceso de diagnóstico diferencial, el estado general de enfermedad y la voluntad del paciente, se propusieron cinco planes de tratamiento y, finalmente, se eligió el plan B conservador compuesto por el tratamiento del canal radicular y tratamiento periapical. Una revisión de la literatura relacionada se añade en este artículo para describir las situación de invaginación radicular, haciendo hincapié en la importancia del diagnóstico y para proporcionar referencias para enfermedades similares futuras.

Solitary Fibrous Tumor in Bladder: A Case Report / 华中科技大学学报（医学）（英德文版）

Solitary fibrous tumor (SFT) in bladder is extremely rare. In this study, we reported one case of bladder SFT and reviewed the only ten cases of the disease that had been reported so far. The patient suffered from residual urine sensation and urethral pain. Cystoscopy revealed a 7-cm protruding mass at the dome of the bladder, and bladder mucosa biopsy showed normal differentiation of the bladder mucosa with a small amount of inflammatory cells. Radical resection of the tumor was performed in this patient. Pathological examination found uniform, haphazardly arranged spindle cells, the majority of which were CD34-positive and Vimentin-positive and proved that the mass was a solitary fibrous tumor. Within a period of 9 months of follow-up, no reoccurrence was found.

Multiple dens evaginatus of premolars and molars in Chinese dentition: a case report and literature review / 国际口腔科学杂志·英文版

Dens evaginatus (DE) is a dental anomaly that occurs as an accessory tubercle on the occlusal or lingual surface of a tooth. The authors provide a literature review and report a rare case in which DE occurs on multiple mandibular premolars and maxillary molars. The patient is a 26-year-old Chinese woman, with a chief complaint of gingival bleeding. DE affecting teeth 17, 27, 35, and 45 was found during clinical examination. For treatment of the patient, we reduced the opposing occluding teeth, while undertaking progressive grinding of the tubercles for six months. We followed-up for a year. This suggests the importance of examining for multiple DE during clinical practice.

Exression Pattern of Testis-specific Expressed Gene 2 in Cryptorchidism Model and Its Role in Apoptosis of Spermatogenic Cells / 华中科技大学学报（医学）（英德文版）

In our previous study,we identified a novel testis-specific expressed gene 2(TSEG-2)from mouse testis.To further investigate its functions,35 male Balb/c mice(8 weeks old)were divided into cryptorchidism group(n=20),sham group(n=10),and control group(n=5).In cryptorchidism group,the right testes were anchored to the inner lateral abdominal wall.In situ hybridization(ISH)was applied to measure the localization of TSEG-2 in mouse testis.Real-time quantitative PCR was performed to detect the expression of TSEG-2 gene.Meanwhile,under the mediation of polyethylenimine(PEI),the recombinant vector pEGFP-TSEG-2(n=5)or empty vector(mock,n=5)was transfected into the testis of male mice.The transfection efficiencies were measured under a fluorescence microscope.The apoptosis of spermatogenic cells was detected by terminal deoxynuleotidyl-mediated nick end labeling(TUNEL).The results showed that TSEG-2 was expressed in convoluted seminiferous tubules,more precisely,in spermatogonia and spermatocytes.As compared with sham and control groups,the TSEG-2 transcription was significantly enhanced(P<0.05)and was correlated with apoptosis of spermatogenic cells in cryptorchid testes(P<0.05).PEI was efficient in mediating transfection of TSEG-2 into seminiferous tubules of testis.One week post-transfection,intratesticular injection of TSEG-2 resulted in increased apoptosis of spermatogenic cells in vivo (P<0.05).These results indicate that TSEG-2 may participate in the apoptosis of spermatogenic cells and the pathogenesis of cryptorchidism.

Expression and significance of TGF-β1 in nasal polyps / 临床耳鼻咽喉头颈外科杂志

Objective:To study the expression and significance of transforming growth factor-β1 (TGF-β1) in nasal polyps.Method:Expression of TGF-β1 in nasal polyps from 34 patients and middle turbinates from 30 patients with deviation of nasal septum were prospectively studied with immunohistochemistry.Each tissue section was observed under optical microscope.Result:①The TGF-β1 positivity in extracellular matrix and in cells in the stroma was significantly higher in nasal polyps than in middle turbinates (P＜0.01).②The distribution and shape of TGF-β1 expressing cells in nasal polyps was similar to that of eosinophil,their positivities were significantly correlative (P＜0.05).③The positivity of TGF-β1 did not correlate with clinical type of nasal polyps (P＞0.05),eosinophil infiltration correlated significantly with clinical type of nasal polyps(P＜0.05).Conclusion:①The TGF-β1 may contribute to some of the pathologic changes observed in nasal polyps,such as thickening of the epithelial basement membrane and stromal fibrosis.②Eosinophils in nasal polyps represent a major source of TGF-β1.③Eosinophils infiltration may play a prominent role in the development and recurrence of nasal polyps.