Development of organic-inorganic polymeric film formers for controlled drug release and wound care

Film forming polymeric systems represents a new and unexplored technology of systems forskin or wounds protection and for controlled drug release. The aim of this work was to study the use of polymeric organic-inorganic ureasil-polyether hybrids synthesized by the sol-gel process as film forming system containing silver sulfadiazine as model drug. The film formationtime can be controlled by changing the precursor/catalyst ratio used during the step of hydrolysis and condensations. The results showed that the precursor/catalyst proportion influences both the visual characteristics and time required to form the film. The precursor/catalyst ratio equal to 20.8 m/v was considered ideal due to promote the homogeneous and transparent film formation in less than 5 minutes. The release profile of sulfadiazine is dependent on the characteristics of the matrixes: matrix more hydrophobic as ureasil-POP provided a slowed released mainly due to the low swelling of the matrix. The more hydrophilic ureasil-POE matrix presents a large capacity to swell and favors the faster release of the drug. The set of results showed the possibility of future use of these systems for treating wounds caused by burns.

Novel solid state nitric oxide sensor using siloxane-poly (oxypropylene) (PPO)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fracture resistance of simulated immature teeth after different intra-radicular treatments

The aim of this study was to evaluate the fracture resistance of simulated immature teeth after different intra-radicular treatments. Crowns and roots of bovine incisors were cut transversally and removed to simulate immature teeth. Root canal preparation and flaring were performed using a bur in crown-apex and apex-crown direction. The samples were distributed into 5 groups (n=10): Positive control (PoC) - no root canal flaring or filling; Negative control (NeC) - teeth were sectioned and their root canals were flared; Direct anatomical glass fiber post (RaP) - #2 Reforpost main glass fiber post relined with composite resin; Double tapered conical glass fiber posts (ExP) - #3 Exacto glass fiber post; and #2 Reforpost main glass fiber + Reforpin accessory glass fiber posts (RrP). In RaP, ExP and RrP, 4.0-mm apical plugs were done with MTA Angelus. The specimens were embedded in polystyrene resin inside cylinders and the periodontal ligament was simulated with a polyether-based impression material. The specimens were submitted to compressive fracture strength test (0.5 mm/min at 135° relative to the long axis of the tooth) in a servo-hydraulic mechanical testing machine MTS 810. Data were subjected to one-way ANOVA and Dunnett's C or Tukey's tests (α=0.05). The control groups (PoC and NeC) showed lower fracture strength than the experimental groups. NeC presented the lowest resistance and ExP presented the highest resistance among the experimental groups. The flaring procedures produced a detrimental effect on the fracture resistance of the bovine teeth. Glass fiber intra-radicular posts increased significantly the fracture resistance of simulated immature teeth.

O impacto do preparo, da cerâmica e do contato oclusal na distribuição de tensões em facetas

Pós-graduação em Odontologia Restauradora - ICT

Influência da geometria oclusal e material restaurador na carga para fratura e distribuição de tensões em coroas totais

Pós-graduação em Odontologia Restauradora - ICT

Avaliação dos parâmetros tempo, corrente e pressão na soldagem por resistência elétrica de compósitos PEI/fibras contínuas: influência na resistência mecânica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of preservative effectiveness of liquid crystalline systems with retinyl palmitate by the challenge test and D-value

The objective of this work was to evaluate the preservative effectiveness of liquid crystalline systems containing retynil palmitate (RP) by the challenge test (CT) and D-value. A system was developed containing water, silicon glycol copolymer, and polyether functional siloxane with 1% RP added. The analyses were carried out by methods in the U.S. Pharmacopeia (USP 31, 2008) using the microorganisms Escherichia coli, Staphylococcus aureus,Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger. The CT showed that after 7 days, all microorganisms were eliminated except A. niger, which maintained viability for at least 28 days after inoculation. Moreover, the microorganisms E. coli, P. aeruginosa, S. aureus, C. albicans and A. niger presented different growth behaviors, evidenced by differences among the D-values calculated. It was concluded that the CT and D-value were efficient methods for evaluation of the preservative property of these formulations.

Influência do comprimento do pino de fibra de vidro na resistência à fratura de raízes fragilizadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)