In vitro assessment of interaction between lidocaine hydrochloride and irrigating solutions on root canal dentin: a scanning electron microscope study / Evaluación in vitro de la interacción entre el clorhidrato de lidocaína y las soluciones de irrigación en la dentina del conducto radicular: un estudio con microscopio electrónico de barrid

Aim: To investigate the precipitate formed from the interaction between 2% lidocaine hydrochloride with adrenaline (LA) with 2.5% sodium hypochlorite (NaOCl) and 0.2% chitosan nanoparticles on root canal dentin, using scanning electron microscopy (SEM). Material and Methods: Sixty mandibular premolars were decoronated, and the root length standardised. The specimens were randomly distributed into the following groups: Group 1 (control): 2% LA mixed with sterile water without root canal instrumentation, Group 2: 2% LA with 2.5% NaOCl in water without root canal instrumentation, and Group 3: 2% LA with 0.2% chitosan nanoparticles in water without root canal instrumentation. Teeth specimens were split and subjected to SEM analysis at cervical, middle, and apical root thirds. On observing precipitate formation in Group 2, 10 premolars were decoronated and treated with 2% LA and 2.5% NaOCl and subjected to root canal instrumentation. Results: Group 1 and Group 3 showed patent dentinal tubules and no precipitate formation. Group 2 showed precipitate blocking dentinal tubules in all the three sections, and the precipitate could not be removed completely after cleaning and shaping. Conclusion: NaOCl forms an insoluble precipitate on interaction with local anaesthetic solution that cannot be removed after chemo-mechanical preparation. Chitosan nanoparticles do not form any such precipitate and show patent dentinal tubules. Hence, chitosan can be used as a flushing irrigant.

Objetivo: Investigar el precipitado formado a partir de la interacción entre el clorhidrato de lidocaína al 2% con adrenalina (LA), el hipoclorito de sodio al 2,5% (NaOCl) y nanopartículas de quitosano al 0,2% en la dentina del conducto radicular, mediante microscopía electrónica de barrido (SEM). Material y Métodos: Se decoraron 60 premolares mandibulares y se estandarizó la longitud de la raíz. Los especímenes se distribuyeron aleatoriamente en los siguientes grupos: Grupo 1 (control): 2% la que fue mezclado con agua estéril sin instrumentación del conducto radicular, Grupo 2: 2% LA con 2,5% de NaOCl sin instrumentación del conducto radicular y Grupo 3: 2 % LA con 0,2% de nanopartículas de quitosano sin instrumentación del conducto radicular. Las muestras de dientes se dividieron y se sometieron a análisis SEM en los tercios radiculares cervical, medio y apical. Al observar la formación de precipitado en el Grupo 2, 10 premolares fueron decorados y tratados con LA al 2% y NaOCl al 2,5% y sometidos a instrumentación de conductos radiculares. Resultado: El Grupo 1 y el Grupo 3 mostraron túbulos dentinarios permeables y sin formación de precipitados. El grupo 2 mostró precipitado que bloqueaba los túbulos dentinarios en las tres secciones, y el precipitado no se pudo eliminar por completo después de limpieza y conformación. Conclusión: el NaOCl forma un precipitado insoluble al interactuar con la solución anestésica local que no se puede eliminar después de la preparación quimiomecánica. Las nanopartículas de quitosano no forman ningún precipitado de este tipo y muestran túbulos dentinarios permeables. Por lo tanto, el quitosano se puede utilizar como irrigante para el lavado.

Synthesis and characterization of chitosan-PVA hydrogel containing PEGylated recombinant epidermal growth factor on cell culture for wound healing substitute

Abstract The aim of the current study was to assess the physicochemical characteristics and wound healing activity of chitosan-polyvinyl alcohol (PVA) crosslinked hydrogel containing recombinant human epidermal growth factor (rh-EGF) or recombinant mouse epidermal growth factor (rm-EGF). The hydrogels were prepared and analyses were made of the morphological properties, viscosity, water absorption capacity, mechanical and bio-adhesive properties. The viscosity of the formulations varied between 14.400 - 48.500 cPs, with the greatest viscosity values determined in K2 formulation. F2 formulation showed the highest water absorption capacity. According to the studies of the mechanical properties, H2 formulation (0.153±0.018 N.mm) showed the greatest adhesiveness and E2 (0.245±0.001 mj/cm2) formulation, the highest bio-adhesion values. Hydrogels were cytocompatible considering in vitro cell viability values of over 76% on human keratinocyte cells (HaCaT, CVCL-0038) and of over 84% on human fibroblast cells (NIH 3T3, CRL-1658) used as a model cell line. According to the BrdU cell proliferation results, B1 (197.82±2.48%) formulation showed the greatest NIH 3T3 and C1 (167.43±5.89%) formulation exhibited the highest HaCaT cell proliferation ability. In addition, the scratch closure assay was performed to assess the wound healing efficiency of formulation and the results obtained in the study showed that F2 formulation including PEGylated rh-EGF had a highly effective role.

Production of 4-Ipomeanol, an anticancer agent from the root tubers and rhizogenic callus of Ipomoea batatas Lam.: A Comparative study.

A comparative study was done on the production of 4-ipomeanol from root tubers of Ipomoea batatas and its rhizogenic callus. Best callusing response was obtained on MS medium supplemented with 11 µM NAA (α-Naphthaleneacetic acid) and 1 µM KIN (Kinetin). Effect of various elicitors (Fusarium solani, chitin and chitosan) on the production of 4-ipomeanol was studied. Methanol extract of the samples were purified by column chromatography and detected using TLC. Identification of 4-ipomeanol was confirmed using HPLC and quantified spectrophotometrically. A mass spectrum was recorded to confirm the presence of 4-ipomeanol. The calli grown under chitin produced highest (6.61mg g-1) amount of 4-ipomeanol. This is the first report on in vitro production of 4-ipomeanol from I. batatas. Since 4-ipomeanol is reported to be present only in I. batatas, this study would help in standardizing protocols for large scale production without affecting its natural flora.

Efecto del quitosano en el desarrollo in vitro de rhizopus stolonifer ehrenb: fr) vuill en dos medios de cultivo / Effect of chitosan on the in vitro developtment of rhizopus stolonifer (ehrenb: fr) vuill on two culture medium

En este trabajo se evaluó el efecto antifúngico del quitosano (0; 0,5; 1,0; 1,5; 2,0 mg mL-1) en el desarrollo in vitro (crecimiento micelial, formación de cuerpos fructíferos, esporulación, germinación y liberación de proteínas) de Rhizopus stolonifer en dos medios de cultivo (papa dextrosa agar y medio mínimo). Los resultados obtenidos demostraron que el quitosano inhibió el crecimiento micelial de R. stolonifer en ambos medios de cultivo. El mayor índice antifúngico se observó en el medio papa dextrosa agar. El quitosano no afectó la formación de los cuerpos fructíferos de R. stolonifer en los medios estudiados. La esporulación y la germinación de las esporas se afectaron en ambos medios de cultivo por efecto de quitosano, siendo más notable en el medio medio mínimo. Se demostró la liberación de proteínas por efecto del quitosano en medio mínimo y caldo papa dextrosa. En general, en este estudio se evidenció el efecto antifúngico del quitosano en el desarrollo in vitro de Rhizopus stolonifer con independencia del medio de cultivo empleado. Sin embargo, en medio medio mínimo podrían observarse mejor los efectos antifúngicos del quitosano.

In this work the antifungal effect of chitosan (0, 0.5, 1.0, 1.5, 2.0 mg mL-1) on the in vitro development (mycelial growth, fruit bodies formation, sporulation, germination and proteins release) of Rhizopus stolonifer on two culture medium (Potato Dextrose Agar and Minimal medium) was evaluated. The obtained results demonstrated that chitosan inhibited the mycelial growth of R. stolonifer in both culture medium. The highest antifungal effect was observed on potato dextrose agar medium. Chitosan was not affected the fruit bodies formation of R. stolonifer on the studied medium. Sporulation and spore germination were affected in both culture mediun by effect of chitosan, it was more noticeable in minimal medium. It was demonstrated proteins release by effect of chitosan in minimal medium and potato dextrose broth medium. In general, in this study it was showed the antifungal effect of chitosan on in vitro development of Rhizopus stolonifer regardless of the culture medium used. However, in minimal medium could be observed best the antifungal effects of chitosan.