The influence of Tween 80 on laccase production by Pleurotus sajor-caju and the efficiency of crude enzyme broth in the removal of bisphenol-A / Influência do Tween 80 na produção de lacases de Pleurotus sajor-caju e eficiência do caldo enzimático bruto na remoção de bisfenol-A

Bisphenol-A is currently considered an environmental pollutant, capable of interfering in the endocrine system of organisms and causing alterations in its development and reproductive system. An alternative method to the chemical treatment of this pollutant has been the use of oxidative enzymes, especially laccases produced by fungi. In order to reduce production costs, agro-industrial waste can be used in the culture medium composition. Nonionic surfactants, which are only slightly toxic to biological membranes, can be applied, as well as Tween 80, to facilitate the excretion of these enzymes into the culture medium. The objectives of this work were: a) characterize the immersion water of banana straw used in the formulation of the culture medium; b) evaluate laccase production by Pleurotus sajor-caju in culture medium with and without addition of Tween 80, through shaken flasks; c) evaluate the efficiency of the crude enzyme broth in degrading bisphenol-A. The shaken flasks were incubated at 30°C for 12 days. The immersion water had a C:N ratio of 13.8, ash percentage of 28.6%, and pH close to neutrality. The addition of Tween 80 on the culture medium (7.5%, m/v) yielded laccase activity and productivity values equal to 3,016.47 U L-1 and 502.7 U L-1 day-1, respectively. These values were 50 and 33.5 times higher than those obtained in the culture medium without addition of Tween 80 for laccase activity and productivity, respectively. The crude enzyme broth degraded 100% of bisphenol-A after 48 hours, regardless of concentration (500, 750 and 1,000 mg L-1).(AU)

O bisfenol-A é considerado um poluente ambiental capaz de interferir no sistema endócrino dos organismos, ocasionando alterações em seu desenvolvimento e sistema de reprodução. Um método alternativo ao tratamento químico desse tipo de poluente tem sido a utilização de enzimas oxidativas, especialmente as lacases, produzidas por fungos. A fim de diminuir custos de produção, resíduos agroindustriais podem compor o meio de cultivo. Assim, surfactantes não iônicos e pouco tóxicos para as membranas biológicas, como o Tween 80, podem ser utilizados para facilitar a excreção dessas enzimas para o meio de cultivo. Os objetivos deste trabalho foram: caracterizar quimicamente o resíduo água de imersão de palha de bananeira, usado na formulação do meio de cultivo; avaliar a produção de lacase por Pleurotus sajor-caju em meio de cultivo líquido (frascos Erlenmeyer) com e sem adição de Tween 80; e avaliar a eficiência do caldo enzimático bruto em degradar bisfenol-A. Os frascos foram incubados a 30°C, por 12 dias. A água de imersão apresentou relação C:N 13,8, percentual de cinzas 28,6% e pH próximo da neutralidade. O cultivo adicionado de Tween 80 (7,5%, m/v) propiciou valores de atividade e produtividade em lacase iguais a 3.016,47 U L-1 e 502,7 U L-1 dia-1, respectivamente. Esses valores são 50 e 33,5 vezes maiores que os obtidos no cultivo sem adição de Tween 80, para atividade e produtividade em lacase, respectivamente. O caldo enzimático bruto degradou 100% do bisfenol-A após 48 horas, independentemente da concentração (500, 750 e 1.000 mg L-1).(AU)

Effect of nonionic surfactants in release media on accelerated in-vitro release profile of sirolimus eluting stents with biodegradable polymeric coating / 药物分析学报

It is a well-known fact that sirolimus (SRL) undergoes degradation process via hydrolysis in aqueous media, leading to incorrect assessment of drug amount and thus release characteristics of formulations. The main objective of the present study was to evaluate the effect of nonionic surfactants in media on in-vitro release profiles for sirolimus eluting stents (SES) coated with biodegradable polymeric matrix. Phosphate buffer and acetate buffer incorporating nonionic surfactants with varying concentrations were examined for adequate solubility and stability (by RP-HPLC). Good sink condition was achieved in phosphate buffer (at pH 4.0) with 1.0%Tween 20, 1.0%Brij 35%and 0.5%Brij 58. Hydrodynamic size (by DLS) and the micelle-water partition coefficient (P) with standard free energy of solubilization (?Gs°) of drug were evaluated to get some understanding about the solubilization phenomena. About 80%of drug release during the period of 48 h was achieved in optimized drug release media which was 1.0%Tween 20 in phosphate buffer pH 4.0. The obtained accelerated SRL release profile in optimized medium cor-related well with the real time in-vitro release in phosphate buffer (pH 7.4). Surface morphology changes (by SEM), changes in gravimetric weights and molecular weight change (by GPC) were examined before and after drug release to understand the drug release mechanism which explains that the polymer did not undergo degradation during the drug release.

Preparation of methotrexate niosomes using freeze-drying of double emulsions method / 中国药学杂志

OBJECTIVE: To prepare nonionic surfactant niosomes by multiple emulsion freeze-drying method and study their encapsulation effects for the water-soluble drug, methotrexate.

Recent trends in niosome as vesicular drug delivery system.

Over decades researchers are striving to use the drugs in an efficient manner to treat various diseases. The efficient use can be explained as reduced dose, reduced side effects, reduced dosage frequency, greater patient compliance and maximum concentration of the drug at the site of action so as to reduce the undue exposure to the entire body. The article focuses on various advantages of vesicular systems (niosomes) to develop the effective delivery system to achieve maximum effective concentration. Niosomes, nonionic surfactant vesicles with lamellar structure which may be unilamellar and multilamellar serve to be efficient in providing these required advantages. The bilayer structure of niosomes being amphiphillic in nature can be used to deliver hydrophilic drugs in its aqueous core and lipophilic drugs in the bilayer made up of surfactants. Various additives in niosomes include nonionic surfactant as film forming agent, cholesterol as stabilizing and rigidizing agent for the bilayer and various charge inducers which develop a charge on the surface of niosomes and stabilize the prepared formulation by the resulting repulsive forces. This article also comprises of various breakthroughs in niosomal delivery of drugs representing various classes. On the basis of above information, the niosomes have been thoroughly exploited for the drug delivery system and still offer scope for research on various drugs for their maximum therapeutic utilization in management and treatment of various dreadful diseases.

Spectrophotometric study of Poloxamer in contact lens care solution / 上海交通大学学报（医学版）

Objective To determine the contents of Poloxamer in contact lens care solution by spectrophotometric method,and investigate the effect of the other lubrication composition on the measurement. Methods Five brands of contact lens care solution with hydroxypropyl methyl cellulose(HPMC)were obtained.The interference of HPMC in contact lens care solution was removed by heating and rapid filtering,and the contents of Poloxamer was determined by KI-I_2 spectrophotometry. Results For the pre-treated contact lens care solution,the tested wavelength was 500 nm and the development time was 120 min.Favourable linearity was observed when Poloxamer ranged between 0.001 mg/mL and 0.020 mg/mL,with standard curve of Y=0.050 91X+0.017 15 and r~2=0.998 2.Precision(n=6)test revealed that RSD was 1.331 4%,and RSD of daytime repeatability experiment was 2.971 3%.The recovery rates of 80%,100%and 120% samples ranged between 90%to 105%. Conclusion KI-I_2 spectrophotometry is a convenient,stable and reliable method,and may sere as a mass control method for nonionic surfactant Poloxamer content in contact lens care solution.