Mining and identification of a biosynthetic gene cluster producing xanthocillin analogues from Penicillium chrysogenum MT-40, an endophytic fungus of Huperzia serrata / 生物工程学报

Xanthocillin is a unique natural product with an isonitrile group and shows remarkable antibacterial activity. In this study, the genome of an endophytic fungus Penicillium chrysogenum MT-40 isolated from Huperzia serrata was sequenced, and the gene clusters with the potential to synthesize xanthocillin analogues were mined by local BLAST and various bioinformatics analysis tools. As a result, a biosynthetic gene cluster (named for) responsible for the biosynthesis of xanthocillin analogues was identified by further heterologous expression of the key genes in Aspergillus oryzae NSAR1. Specifically, the ForB catalyzes the synthesis of 2-formamido-3-(4-hydroxyphenyl) acrylic acid, and the ForG catalyzes the dimerization of 2-formamido-3-(4-hydroxyphenyl) acrylic acid to produce the xanthocillin analogue N, N'-(1, 4-bis (4-hydroxyphenyl) buta-1, 3-diene-2, 3-diyl) diformamide. The results reported here provide a reference for further discovery of xanthocillin analogues from fungi.

Optimization of cosmetic formulations development using Box-Behnken design with response surface methodology: physical, sensory and moisturizing properties

Considering the importance of an adequate composition of the formulation in the development of stable, safe and effective cosmetic products, experimental design techniques are tools that can optimize the formulation development process. The objective of this study was to develop topical formulations using the Box-Behnken design with response surface methodology and evaluate its physical, sensory and moisturizing properties. The experimental design used in the first step allowed to identify and to quantify the influence of raw materials, as well as the interaction between them. In the second step, the analysis identified the influence of soy lecithin, the phytantriol and capric acid triglyceride and caprylic on the consistency index, stickiness and greasiness and skin hydration. Cetearyl alcohol, dicetyl phosphate and cetyl phosphate 10EO and acrylates/C10-30 alkylacrylate crosspolymer showed effects in rheological parameters. The addition of soy lecithin had significant effects in terms of consistency index, stickiness, oiliness and immediate moisturizing effects. Phytantriol showed effects on increasing consistency index and oiliness sensation. Thus, the experimental design was shown to be an effective tool for research and development of cosmetics, since it allowed the assessment of the individual and interaction effects of raw materials in the responses: rheological parameters, sensory and clinical efficacy.

Idiosyncratic reaction after injection of polyacrylate - polyalcohol copolymer

ABSTRACT Context: Polyacrylate-polyalcohol copolymer is a synthetic product, non-biodegradable, with low rate of therapeutic failure and lower incidence of reactions at the site of injection, when compared to biodegradable agents. We report an unprecedent, exuberant and persistent inflammatory reaction following injection of that substance. Patient: a 17 years-old patient with vesico-ureteral reflux and complete pyelocaliceal right duplication was submitted to treatment with polyacrylate-polyalcohol copolymer (STING technique). In the seventh day of post-operatory, she presented intense dysuria and hypogastric pain, without laboratory exams alterations; a symptomatic treatment was started. After two months, the symptoms persisted and an ultrasound detected thickening of bladder wall close to the uretero-vesical junction. After that exam, a cystostopic biopsy showed epithelial hyperplasia with increased edema of lamina propria, suggesting an adverse reaction to the polymer. After four months, there was complete remission, but the reflux persisted with the same grade. Hypothesis: This is an unprecedent reaction following injection of this copolymer. The presence of characteristics such as absence of infection, temporal relation between treatment and beginning of symptoms, and detection of epithelial hyperplasia at the local of injection reinforce the hypothesis of association of the substance and adverse reaction. In that patient, important complains motivated early investigation of urinary tract, that confirmed those aspects. Maybe if that reaction had occurred in patients with lower capacity of expression (such as in infants) it would be unnoticed.

Preparation and evaluation of blank and doxorubicin loaded poly (acrylic acid) microspheres for embolization / 北京大学学报(医学版)

OBJECTIVE@#To prepare ion exchange doxorubicin-loaded poly (acrylic acid) microspheres (DPMs) and evaluate the properties of these chemoembolic agents.@*METHODS@#Poly (acrylic acid) microspheres (PMs) without drug were prepared by inverse suspension polymerization method and then doxorubicin was loaded by ion exchange mechanism to prepare DPMs. Optical microscope was used to investigate the morphology and particle size distribution of PMs and DPMs; fluorescence microscope and confocal microscope were used to observe the distribution of doxorubicin after drug loading. Elasticities of both the microspheres were evaluated by texture analyzer. High performance liquid chromatography (HPLC) method was established to determine the drug loading behavior of PMs and releasing behavior of DPMs. The in vivo embolic property was evaluated by embolizing the hepatic artery of a rabbit with 0.1 mL of DPMs.@*RESULTS@#PMs and DPMs were both spherical in shape, smooth in surface and dispersed well. Doxorubicin was mainly in the outer area inside of DPMs and distributed evenly. The average particle size of PMs and DPMs were (283±136) μm and (248±149) μm, respectively. PMs and DPMs both had good compression ability with the Young's modulus of (62.63±1.65) kPa and (93.94±1.10) kPa separately. PMs reached the drug loading balance at 12 h, and the entrapment efficiency was greater than 99%. Drug loading of PMs in doxorubicin solution at the concentration of 5.0 g/L and 12.5 g/L was (19.78±0.27) g/L and (49.45±0.37) g/L, respectively. Doxorubicin released slowly from DPMs in PBS and the accumulative release percentages of DPMs with corresponding drug loading were 6.82%±0.02% and 2.83%±0.10% after 24 h, respectively. Arterial angiograms showed that the hepatic artery of the rabbit was successfully embolized with DPMs.@*CONCLUSION@#DPMs with good performance of loading doxorubicin could be a potential embolic agent for transcatheter arterial chemoembolization.

The effects of monomers used in polymeric biomaterials on renal tissue / Efectos de los monómeros de los biomateriales poliméricos utilizados en tejido renal

SUMMARY: Biomaterials are mostly polymers and are used in artificial organ production in contemporary medicine. They are prepared by the polymerization reaction of many monomers. There are many monomers used in biomaterial production. In this study, we investigated whether acrylamide (AAm), methacrylamide (MAAm), N-isopropylacrylamide (NIPAm) and acrylic acid (AAc) used in polymeric biomaterial production had histopathological effects on renal tissue. In the present study, Wistar albino rats weighing ~ 250-300 g were used. Following the intramuscular injections of 1 mL aqueous monomer solutions at 50 mg/kg concentrations, acrylamide group animals were sacrificed at 1st, 2nd and 3rd weeks, the other monomer group animals were sacrificed at 1st, 2nd, 4th and 6th weeks. One mL serum physiologic were injected intramuscularly to the control group animals at the same time intervals with the experimental group animals. After histological follow-up, serial sections were prepared for evaluation under light microscope. In addition, the diameters of glomeruli and glomeruli space (Bowman's space) are measured, and the changes of the values of all groups with the exposure time were investigated. Acrylamide and its derivatives cause glomerular, arteriolar and tubule interstitial damage in the renal tissue. The narrowing glomeruli space, increasing diffuse mesangial matrix and tubular dilation was observed in some groups. In addition, dilatation, dissociation of tubular epithelium, thickening basement membranes and glycogenic vacuolization was also noted. These adverse results may be due to residual monomer. There should be no monomer residue in the polymer used as biomaterials.

RESUMEN: Los biomateriales en su mayoría son polímeros utilizados en la producción de órganos artificiales en la medicina contemporánea. Éstos son preparados mediante la reacción de polimerización de varios monómeros. Existe una gran cantidad de monómeros usados en la producción de biomateriales. En este estudio se investigó si la acrilamida (AAm), la metacrilamida (MAAm), la N-isopropilacrilamida (NIPAm) y el ácido acrílico (AAc) utilizados en la producción de biomateriales poliméricos tuvieron efectos histopatológicos en el tejido renal. En el presente estudio, se utilizaron ratas Wistar albinas que pesaban 250-300 g. Después de las inyecciones intramusculares (1 ml) de soluciones acuosas de monómero a concentraciones de 50 mg / kg, los animales del grupo de la acrilamida se sacrificaron a la 1ª, 2ª y 3ª semanas, los otros animales del grupo monómero se sacrificaron a las 1ª, 2ª, 4ª y 6ª semanas. Se inyectaron intramuscularmente 1 ml de suero fisiológico a los animales del grupo control en los mismos intervalos de tiempo que los animales del grupo experimental. Después del análisis histológico, se prepararon secciones en serie para su evaluación bajo microscopio óptico. Además, se midieron los diámetros de los glomérulos y el espacio glomerular, y se investigaron los cambios de los valores de todos los grupos con el tiempo de exposición. La acrilamida y sus derivados causaron daño intersticial glomerular, arteriolar y tubular en el tejido renal. El estrechamiento del espacio de los glomérulos, el aumento de la matriz mesangial difusa y la dilatación tubular se observó en algunos grupos. Además, también se observó dilatación, disociación del epitelio tubular, membranas basales espesantes y vacuolización glicogénica. Estos resultados adversos pueden deberse al monómero residual. No debe haber residuo de monómero en el polímero utilizado como biomateriales.

The outcomes of two different bulking agents (dextranomer hyaluronic acid copolymer and polyacrylate-polyalcohol copolymer) in the treatment of primary vesico-ureteral reflux

ABSTRACT Purpose Subureteral injection of bulking agents in the endoscopic treatment of vesicoureteral reflux is widely accepted therapy with high success rates. Although the grade of vesicoureteric reflux and experience of surgeon is the mainstay of this success, the characteristics of augmenting substances may have an effect particularly in the long term. In this retrospective study, we aimed to evaluate the clinical outcomes of the endoscopic treatment of vesicoureteric reflux (VUR) with two different bulking agents: Dextranomer/hyaluronic acid copolymer (Dx/HA) and Polyacrylate polyalcohol copolymer (PPC). Materials and Methods A total 80 patients (49 girls and 31 boys) aged 1-12 years (mean age 5.3 years) underwent endoscopic subureteral injection for correction of VUR last six years. The patients were assigned to two groups: subureteral injections of Dx/HA (45 patients and 57 ureters) and PPC (35 patients and 45 ureters). VUR was grade II in 27 ureters, grade III in 35, grade IV in 22 and grade V in 18 ureters. Results VUR was resolved in 38 (66.6%) of 57 ureters and this equates to VUR correction in 33 (73.3%) of the 45 patients in Dx/HA group. In PPC group, overall success rate was 88.8% (of 40 in 45 ureters). Thus, Thus, this equates to VUR correction in 31 (88.5%) of the 35 patients. Conclusions Our short term data show that two different bulking agent injections provide a high level of reflux resolution and this study revealed that success rate of PPC was significantly higher than Dx/HA with less material.

Water and Physiological Saline to Prevent the Formation of P-Chloroaniline / Agua y Suero Fisiológico para Prevenir la Formación de Paracloroanilina

This study determined if p-chloroaniline (PCA) can be minimized by using distilled water and physiological saline solution following sodium hypochlorite but before chlorhexidine. Hypochlorite 5%, 0.5%, 0.05%, 0.005% and 0.0005% dissolved in 0.9% NaCl and in distilled water were mixed with 2% chlorhexidine for the formation of PCA. The PCA was determined using UV-VISIBLE spectrometry, with spectral curve was determined the wavelength of maximum absorption of PCA. Formed PCA absorbance was measured between 0.025%, 0.02%, 0.015%, 0.01%, 0.005% and 0.0025% hypochlorite and 2% chlorhexidine. 2% chlorhexidine and hypochlorite with physiological saline form a white precipitate which prevents the measurement of PCA. Colored PCA is formed with 0.05%, 0.005% hypochlorite aqueous dilutions and 2% chlorhexidine. The lwavelength of maximum absorption obtained was 470 nm and absorbance of PCA showed a linear decrease. 0.005% NaClO produces the least amount of PCA. The best solvent to prevent the formation of PCA during the interaction of sodium hypochlorite with chlorhexidine is distilled water.

Este estudio determinó si la p-cloroanilina (PCA) puede ser minimizada mediante el uso de agua destilada y solución salina fisiológica seguido de la aplicación de hipoclorito de sodio, previo a la aplicación de clorhexidina. Hipoclorito al 5%, 0,5%, 0,05%, 0,005% y 0,0005% fue disuelto en 0,9% de NaCl y en agua destilada se mezcló con 2% de clorhexidina para la formación de PCA. El PCA se determinó mediante espectrometría UV-Visible, y con curva espectral se determinó la longitud de onda máxima del PCA. La absorbancia del PCA formado se midió con 0,025%, 0,02%, 0,015%, 0,01%, 0,005% y 0,0025% de hipoclorito y 2% de clorhexidina. La combinación de 2% de clorhexidina e hipoclorito en solución salina fisiológica forman un precipitado blanco que impide la medición del PCA. El PCA coloreado es formado con 0,05%, 0,005% diluciones acuosas de hipoclorito y 2% de clorhexidina. La longitud de onda máxima obtenida fue de 470 nm y la absorbancia del PCA mostró una disminución lineal. NaClO al 0,005% produce menor cantidad de PCA. El mejor disolvente para evitar la formación de PCA durante la interacción de hipoclorito de sodio con clorhexidina es agua destilada.

Influence of formulation technique on acrylate methacrylate copolymer modified paracetamol matrix tablets

This work was designed to evaluate the influence of various methods such as dry granulation [DG], wet granulation [using the polymer in an ethanolic solution [WGO] or aqueous dispersion [WGA] and solid dispersion [SD] techniques, on properties of paracetamol matrix tablets prepared using varying concentrations of acrylate methacrylate copolymer. Tablet properties were investigated using official and unofficial standards. Drug dissolution profile assessed at pH 1.2 was studied spectrophotometrically at lambda[max] of 245 nm. With the use of various kinetic models, the release mechanism of the drug was analyzed. The parameters, maximum amount of drug release [m[infinity]] at time t[infinity] were obtained, m[infinity] was >/= 91.36 %, while t[infinity] was >/= 4.5 h. The release rate constant [k] for DG tablets was 15.61 h[-1], while, WGO, WGA and SD tablets were 12.90, 11.03 and 10.75 h[-1] respectively. The matrix tablets, which exhibited marked retardation in drug release displayed a Higuchi square root of time model [R[2] > 0.98]. The mechanism through which the drug was released was governed by Fickian diffusion release [n values < 0.5]. The performance of the drug was affected by the formulation technique in the order of SD > WGO > WGA > DG

investigation into the drug release from ibuprofen matrix tablets with ethylcellulose and some poly-acrylate polymers

This study was performed to achieve sustained-release Ibuprofen matrix tablets with a zero-order release kinetic while most of the previous formulations have shown Higuchi release kinetic. Considering the results from previous studies, ethyl cellulose, Carbopol 934P, Carbopol 974P, and Pemulen TR-1 were used at different amounts for preparation of the tablets by direct compression. The release profiles were studied in a two-stage release test using nonlinear regression analysis. Carbopols 934P and 974P could not sustain the release adequately while Pemulen TR-1 had too strong sustaining effect. Therefore, combination formulations were considered and studied. The release profiles of ethyl cellulose formulation and the combination formulation consisting Carbopol 934P and Pemulen TR-1 best fitted in Higuchi model, although the zero-order model was not completely rejected. However, the kinetic model of release from the combination formulation consisting Carbopol 974P and Pemulen TR-1 changed to zero-order indicating the most constant release rate among formulations. This was speculated to be due to some erosion of the gel, as well as some interaction of the hydrophobic chain of Pemulen TR-1 with Ibuprofen. Therefore, this formulation is suggested for directly compressed sustained-release matrix tablets of Ibuprofen with a more constant release rate.

Eradication of a Mature Methicillin-Resistant Staphylococcus aureus (MRSA) Biofilm From Acrylic Surfaces

Methicillin-resistant Staphylococcus aureus (MRSA) can grow as structured biofilm in different surfaces, including oral mucosa and denture surfaces. Such biofilms can be released into the oral fluids and aspirated, causing systemic infections such as aspiration pneumonia. This study evaluated the efficacy of two disinfectant solutions and microwave irradiation in disinfecting acrylic specimens contaminated with MRSA biofilm. Thirty-six acrylic specimens were made, sterilized and contaminated with MRSA (107 cfu/mL). After incubation (37 °C/48 h), the specimens were divided into 4 groups: not disinfected (positive control); soaking in 1% sodium hypochlorite for 10 min; soaking in 2% chlorhexidine gluconate for 10 min; and irradiating by microwave for 3 min at 650 W. The viability of cells was evaluated by XTT reduction method. All specimens from the positive control group showed biofilm formation after 48 h incubation. The mean absorbance value of the control specimens was 1.58 (OD at 492 nm). No evidence of biofilm formation was observed on specimens after the disinfection methods. Disinfection by soaking in 1% sodium hypochlorite and 2% chlorhexidine gluconate and irradiating by microwaves resulted in 100% reduction of MRSA biofilm metabolism. The use of chemical solutions and microwave irradiation was shown to be effective for eradicating mature MRSA biofilms on acrylic resin specimens.

Staphylococcus aureus resistente à meticilina (MRSA, do inglês methicillin-resistant Staphylococcus aureus) pode crescer como biofilme estruturado em diferentes superfícies, incluindo mucosa bucal e superfícies de próteses. Estes biofilmes podem se dispersar nos fluidos orais e ser aspirados, causando infecções sistêmicas, como a pneumonia aspirativa. Este estudo avaliou a eficácia de duas soluções desinfetantes e irradiação por microondas na desinfecção de corpos-de-prova acrílicos contaminados com biofilme de MRSA. Trinta e seis espécimes de resina acrílica foram fabricados, esterilizados e contaminados com MRSA (107 ufc/mL). Após a incubação (37 °C/48 h), os espécimes foram divididos em quatro grupos: não desinfetados (controle positivo); imersos em hipoclorito de sódio 1% por 10 min; imersos em gluconato de clorexidina 2% por 10 min e irradiados por microondas durante 3 min a 650 W. A viabilidade das células foi avaliada pelo método de redução de XTT. Todos os espécimes do grupo controle apresentaram formação de biofilme após 48 h de incubação. O valor médio de absorbância destes espécimes foi de 1.58 (OD a 492 nm). Nenhuma evidência de formação de biofilme foi observada em todas as amostras desinfetadas. A desinfecção em hipoclorito de sódio 1%, gluconato de clorexidina 2% e irradiação em microondas resultou em 100% de redução do metabolismo do biofilme de MRSA. O uso de soluções químicas e irradiação em microondas mostrou-se eficaz na eliminação do biofilme maduro de MRSA sobre corpos-de-prova de resina acrílica.

Progress in biotransformation of bio-based lactic acid / 生物工程学报

Fermentative production of lactic acid, an important bio-based chemicals, has made considerable progress. In addition to the food industry and production of polylactic acid, lactic acid also can be used as an important platform chemical for the production of acrylic acid, pyruvic acid, 1,2-propanediol, and lactic acid esters. This article summarizes the recent progress in biocatalytic production of lactic acid derivatives by dehydration, dehydrogenation, reduction, and esterification. Trends in the biotransformation of lactic acid are also discussed.

The effects of surface glazing materials on dental sealant surface hardness and roughness / 대한구강보건학회지

OBJECTIVES: To assess the effect of glazing materials with different sealants on sealant surface roughness and surface hardness. METHODS: Ultraseal XT(TM) sealant (group 1) and 3M Concise(TM) sealant (group 2) were applied on the buccal surfaces of 26 bicuspid teeth per group. The buccal surface of each tooth was then divided into two half surfaces for 52 halves per group. BisCover LV(TM) glaze was applied to one of the two buccal half surfaces of randomly selected 13 teeth per group. For the other remaining 13 teeth per group, we applied Fortify(TM) glaze to one of the two half surfaces. The remaining 26 buccal half surfaces per group covered with sealant only, did not receive any glaze. The surface roughness and hardness of each sample was measured, and the average value of the three measurements from the individual sample was calculated. The sample surfaces were also observed by scanning an electron microscopy. RESULTS: Two-way ANOVA with surface roughness and hardness as the individual dependent variables identified a statistically significant interaction between the sealants and glazing materials. BisCover LV lowered Ultraseal XT surface roughness and application of surface glazing materials on 3M Concise promoted the hardness. Micro-cracks were identified on the surface in no glaze compared to being less in any glaze. CONCLUSIONS: Surface glaze material could improve the surface roughness and hardness of the selected pit and fissure sealant material. Such a sealant-reinforcing procedure, involving surface glazing, may be clinically useful.

Effect of different surface penetrating sealants on the roughness of a nanofiller composite resin

This study evaluated the effectiveness of different sealants applied to a nanofiller composite resin. Forty specimens of Filtek Z-350 were obtained after inserting the material in a 6x3 mm stainless steel mold followed by light activation for 20 s. The groups were divided (n=10) according to the surface treatment applied: Control group (no surface treatment), Fortify, Fortify Plus and Biscover LV. The specimens were subjected to simulated toothbrushing using a 200 g load and 250 strokes/min to simulate 1 week, 1, 3 and 6 months and 1 and 3 years in the mouth, considering 10,000 cycles equivalent to 1 year of toothbrushing. Oral-B soft-bristle-tip toothbrush heads and Colgate Total dentifrice at a 1:2 water-dilution were used. After each simulated time, surface roughness was assessed in random triplicate readings. The data were submitted to two-way ANOVA and Tukey's test at a 95% confidence level. The specimens were observed under scanning electron microscopy (SEM) after each toothbrushing cycle. The control group was not significantly different (p>0.05) from the other groups, except for Fortify Plus (p<0.05), which was rougher. No significant differences (p>0.05) were observed at the 1-month assessment between the experimental and control groups. Fortify and Fortify Plus presented a rougher surface over time, differing from the baseline (p<0.05). Biscover LV did not differ (p>0.05) from the baseline at any time. None of the experimental groups showed a significantly better performance (p>0.05) than the control group at any time. SEM confirmed the differences found during the roughness testing. Surface penetrating sealants did not improve the roughness of nanofiller composite resin.

Este estudo avaliou a efetividade de diferentes selantes aplicados a uma resina nanoparticulada. Quarenta espécimes de Filtek Z-350 foram obtidos depois da inserção do material em um molde de aço inoxidável seguido por fotoativação por 20 s. Os grupos foram divididos (n=10) de acordo com o tratamento superficial aplicado: Grupo controle (sem tratamento superficial), Fortify, Fortify Plus ou Biscover LV. Os espécimes foram submetidos a escovação simulada usando uma carga de 200 g e 250 ciclos/min para simular 1 semana, 1, 3 e 6 meses e 1 e 3 anos, considerando que 10.000 ciclos equivalem a um ano de escovação. Escovas Oral-B de cabeça macia e dentifrício Colgate Total diluído a 1:2 em água foram utilizados. Depois de cada período de simulação, a rugosidade superficial foi medida em triplicata. Os dados foram submetidos à ANOVA de dois fatores e ao teste de Tukey com nível de 95% de confiança. Os espécimes foram observados em microscopia eletrônica de varredura (MEV) depois de cada ciclo de escovação. O grupo controle não foi diferente (p>0,05) que os outros grupos, exceto pelo Fortify Plus (p<0,05), que foi mais rugoso. Nenhuma diferença (p>0,05) foi observada em 1 mês de simulação entre os grupos experimentais e o controle. Fortify e Fortify Plus apresentaram rugosidade regular com o tempo, diferindo da inicial em todos os tempos. Nenhum dos grupos selados mostrou melhor desempenho (p>0,05) que o grupo controle em qualquer um dos tempos. MEV ressaltou as diferenças encontradas durante o teste de rugosidade. Selantes de penetração de superfície não melhoram a rugosidade da resina nanoparticulada.

effect of linear PEI on characteristics and transfection efficiency of PEI-based cationic nanoliposomes

The development of efficient and safe carrier system to transfer DNA into cells is essential in non-viral gene therapy. The aim of the present study was to evaluate the effect of linear polyetheneimine [lPEI] [2500 Da] on the physicochemical and biological properties of lipopolyplexes constructed from liposomes and lPEI. Different lipopolymers were synthesized from lPEI and acrylate derivatives. Nanocarriers were composed of the lipids [DOPE, DPPE and DOTAP] and the synthesized lipopolymers. After characterization of the prepared vectors by determination of size and zeta potential, transfection activity was tested in Neuro2A cells. Ethidium bromide and MTT test were used to evaluate the DNA condensation ability and cytotoxicity of vectors, respectively. Vector's size ranged from 95 to 337 nm and they had positive charge. The differences in DNA binding properties of lipopolyplexes were not significant. Among lipids, DOTAP showed better impact on transfection efficiency. The highest transfection activity was achieved by liposomal formulation consist of DOTAP and lipopolymer composed of lPEI and hexyl acrylate. The lipopolyplexes showed minimum cytotoxicity to the cultured cells in vitro. The results of study confirmed that it is possible to improve gene expression using lipopolyplexes

effect of resin coating technique on shear bond strength

The purpose of this study was to investigate the shear bond strength of metal discs luted to dentine using Resin Coating Technique. In this study the adhesives used were dentine bonding agents, namely, Clearfil SE Bond and Syntac Sprint which were applied one week prior to cementation of Cobalt Chromium [Co-Cr] alloy discs to determine if there was any increase in the bond strengths when later luted using Panavia F and Variolink II. Thus there were four test groups with twelve teeth in each group i.e. Group I:Panavia F, Group II: Clearfil SE Bond I Panavia F, Group III: Variolink Hand Group IV: Syntac Sprint I Variolinkll. The mean shear bond strengths for the four test groups were recorded and the data were compared. It was found that the bond strengths increased significantly with the coating of the dentine bonding agents

Formulation development and Theological studies of palatable cefetamet pivoxil hydrochloride dry powder suspension

Because of its intense bitter taste and susceptibility to moisture Cefetamet Pivoxil [CPH] is presently available only in the form of tablet. The aim of this study was to develop taste masked CPH dry powder suspension. Methods employed for formulations were: a] Film coating of CPH using Eudragit El00 and subsequent adsorption on different carriers such as spray-dried lactose, sodium starch glycolate and spray-dried mannitol and b] Complexation of CPH with three different ion exchange resins indion 234 amberlite IRP64 and amberlite IRP69. Taste viz evaluation as recognized by volunteers revealed that coating with Eudragit El00 and subsequent adsorption on different carriers do not mask the bitter taste of the drug. Suspensions prepared using amberlite IRP64 and amberlite IRP69 were extremely palatable with no bitter after taste. They showed pseudoplastic flow behavior and were too viscous even after shearing for sufficient duration of time and exhibited poor pourability. The suspension made with indion 234 was palatable with slight or no bitter after taste. It demonstrated plastic flow with negligible thixotropy. It had moderate viscosity at rest and could be poured after a reasonable amount of shaking. CPH dry powder suspensions were very unstable under different conditions except under refrigeration. A 5% degradation of drug was occurred in reconstituted suspension in 4 days period when stored at room temperature. Dry powder suspension prepared with indion 234 having 5% overages was stable even after 4th day of reconstitution and palatable with slight or no bitter after taste

Preparation, characterization and release of verapamil hydrochloride from polycaprolactone/ acrylic acid [PCL/AA] hydrogels

In this study pH sensitive, biocompatible and controlled released hydrgels were prepared and their localized drug delivery effect was analyzed. Polycaprolactone and acrylic acid [PCL/AA] were reacted by free radical polymerization and developed inter penetrating polymeric network [IPN] hydrogels. Benzylperoxide was used as initiator and N, N methylenebisacrylamide [NNMBisAm] was employed as a cross-linking agent. Different concentrations of monomer, polymer and cross-linking agent were used and the reaction parameters were optimized. The obtained PCL/AA hydrogels were fully characterized by Fourier transform infrared spectroscopy [FT-IR], scanning electron microscopy [SEM], and thermogravimetric analysis [TGA] that determined the polymer structure, its morphology and strength respectively. Verapamil, a calcium channel blocker was loaded by incubation of polymerization method. Controlled release Verapamil hydrogel was developed due to its low solubility; low permeability and having very short half life of 1.2-2 h. The dynamic swelling, equilibrium swelling and drug release were carried out in a buffer solution of pH 1.2, 4.5 and 6.8. Concentration of Acrylic acid showed direct, while Polycaprolactone inverse relation to swelling and drug release due to their hydrophilic and hydrophobic nature respectively. Cross-linking agent also had the contrary effect on swelling. Diffusion coefficient [D] of hydrogels was determined by using Flory-Rehner theory. Drug release and swelling data were analyzed by different kinetic models, like Zero order, First order, Higuchi, Korsmeyer's and Peppas. The release and diffusion was best described by the first order kinetics where n value was <0.5 for all the formulations indicating Fickian drug release mechanism

Preparation method of polystyrene core-poly (acrylamide-acrylic acid) shell fluorescent microspheres / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the preparation method of polystyrene core-poly (acrylamide-acrylic acid) shell fluorescent microspheres.</p><p><b>METHODS</b>The polystyrene core-poly (acrylamide-acrylic acid) shell (P-(St-co-AAM)) fluorescent microspheres were prepared using fluorescent microspheres as the core and acrylamide/acrylic as polymerization monomer. Reaction conditions affecting the morphology of core-shell structure including feeding mode, initiator, cross linker, pH, concentration and swelling were studied.</p><p><b>RESULT</b>Fluorescent microscopy showed that the relatively uniform particle sizes were distributed in a range of 7-8 μm. Fourier transform infra-red spectroscopy (FT-IR) proved the existence of poly (acrylamide-acrylic acid) shell and amide group on the surface. The optimal conditions for seeding polymerization: azobisisobutyronitrile was used as the initiator in the absence of cross linker, after a 40 h swelling treatment by using alcohol with the appropriate reaction temperature (70 degree), reaction time (3 h) and pH(6-7). The average dispersion and stability were 25.14 % and 90.21%, respectively. The fluorescein release percentage was kept stable at approximately 30% after 40 h.</p><p><b>CONCLUSION</b>The fluorescent microspheres prepared by this method have core-shell structure and satisfactory fluorescence properties with good dispersion and stability.</p>

Effect of Phyllanthus emblica Linn. on candida adhesion to oral epithelium and denture acrylic

OBJECTIVE@#To investigate the effect of Phyllanthus emblica (P. emblica) Linn. ethanolic extract on the adhesion of Candida albicans (C. albicans) to human buccal epithelial cells (BECs) and denture acrylic surfaces.@*METHODS@#Human BECs and transparent acrylic strips were pretreated with ethanolic extract solution of P. emblica fruits at concentration ranged from 18.7 to 300 mg/mL. After washing BECs and the strips were inoculated with three strains of C. albicans (ATCC 10281 and two clinical isolates) (10(7) cells/mL). Normal saline solution (NSS) and 0.2% chlorhexidine gluconate were used as negative and positive controls, respectively. BECs were harvested on 12 μm-polycarbonate filters (Millipore, USA). The membrane filters and the strips were stained with Gram stain. Adherent yeast cells on 100 randomly selected epithelial cells and 20 randomly selected fields on each strip were counted under microscope. The statistical significance was calculated by Kruskal-Wallis and Tukey tests at a significant level of P< 0.05.@*RESULTS@#Significant lower numbers of all strains of yeasts adhering to BECs and acrylic strips were observed after exposure to 75-300 mg/mL of plant extract compared with NSS.@*CONCLUSIONS@#The present study demonstrates that P. emblica ethanolic extract interferes with the adhesion of C. albicans to BECs and denture acrylic surfaces in vitro.