Plastics monolayers

Plastic monolayer in contact with liquid food... 

These criteria are not in any particular order and some may conflict with one another. Fortunately for food packaging, in cases where no single plastics monolayer can satisfy all the functional requirements, recently applied technologies such as co-extrusion and lamination can provide complete solutions. The most commonly used plastics for the manufacture of FCMs are given below. 

Physical and ionic adsorption may be either monolayer or multilayer (12). Capillary stmctures in which the diameters of the capillaries are small, ie, one to two molecular diameters, exhibit a marked hysteresis effect on desorption. Sorbed surfactant solutes do not necessarily cover ah. of a sohd iaterface and their presence does not preclude adsorption of solvent molecules. The strength of surfactant sorption generally foUows the order cationic > anionic > nonionic. Surfaces to which this rule apphes include metals, glass, plastics, textiles (13), paper, and many minerals. The pH is an important modifying factor in the adsorption of all ionic surfactants but especially for amphoteric surfactants which are least soluble at their isoelectric point. The speed and degree of adsorption are increased by the presence of dissolved inorganic salts in surfactant solutions (14). 

Figure 5 The Costar Transwell system with a cell monolayer grown on a porous polycarbonate filter that is mounted onto a removable plastic insert forming the apical chamber. Two other systems, (1) the Costar diffusion chamber system, where a filter-grown (Snap-well) cell monolayer is sandwiched between two chambers of equal volume and the bathing solutions are agitated and/or gassed and (2) filter-grown cell monolayers mounted in a two-chamber rotating cylinder device (Imanidis et al., 1996), are not shown.

It is noteworthy that the kinetics viewed from the donor and receiver sides are seemingly independent of each other. As discussed in the next section, this prompts the employment of experimental strategies to understand the events of drug uptake and efflux mechanistically and independently through drug uptake studies with cell monolayers cultured on flat plastic dishes, drug efflux from the... 

Figure 33 Uptake kinetics of PNU-78,517 by MDCK cell monolayers grown on a solid plastic surface as a function of bovine serum concentration in the bathing solution. [Redrawn from Raub et al. (1993) with permission from the publisher.]...

Given the low permeability of the antioxidant across MDCK cell monolayers and its large membrane partition coefficient, efflux kinetic studies using drug-loaded cell monolayers cultured on plastic dishes could yield useful information when coupled with the following biophysical model. The steady-state flux of drug from the cell monolayer is equal to the appearance rate in the receiver solution ... 

The aforementioned studies employing various kinetic boundary conditions (uptake by the monolayers on a plastic substrate, efflux from the apical (AP) membrane of plastic-grown cells pre-equilibrated with drug, and efflux from the basolateral (BL) membrane of filter-grown cells pre-equilibrated with drug) permit the mechanistic and quantitative dissection of the kinetic process of apical-to-basolateral translocation of membrane-interative compounds in the presence and absence of BSA. The mathematical model for transmonolayer kinetics follows. 

Electron microscopic evaluation of infected Caco-2 monolayers grown on membranes, under conditions that induced cellular polarization, prompted the conclusion that the larvae occupy the cytoplasm of cells they invade (ManWarren et al., 1997). Apical and basal plasma membranes appeared to be preserved in infected cells (Fig. 6.3). These findings reproduced the observations of Wright (1979) in his examination of intestinal tissues from infected mice. In contrast, when Li et al. (1998) performed similar experiments in HT29 monolayers grown on plastic, they concluded... 

Seek T75 plastic tissue culture flasks with a minimum of 2.5 x 106 cells in 120ml of Eagle s medium containing 20mM L-glutamine 0.88g l-1 sodium bicarbonate 20 mM HEPES 50 pg ml-1 streptomycin sulphate 50IUml 1 benzyl-penicillin and 7.5% fetal bovine serum. The flasks are incubated for 18-24 h at 37°C in a C02 incubator to establish monolayer cultures. 

ATII cells, when plated on permeable supports or plastics under appropriate culture conditions, acquire features of type I cell-like phenotype and morphology [30, 57, 80], Although isolation of ATI pneumocytes from rat lungs has recently been reported with some success [28, 48, 81], development of confluent ATI cell monolayer with electrically tight characteristics has not been reported yet. It should be noted that unlike many other cells in primary culture, AEC exhibits generally a very limited proliferation profile and is therefore not suitable for passaging. Thus, a new preparation of cells has to be used for each data set, which drives the costs up tremendously, and a reliable normalisation scheme of data observed from each set of cell preparations is needed. 

Hydraulic, fuel and water hoses truck air brake hoses monolayer and multilayer plastic fuel lines. .. 

The effects of interfacial monolayers on the extraction from drops are particularly striking. Early work showed that traces of either impurity or surface-active additives can drastically reduce extraction rates even plasticiser, in subanalytical quantities dissolved from plastic tubing by benzene, reduces the mass-transfer rate by about ten times by retarding... 

All solutions should be prepared in DMEM or other suitable growth medium containing 5% FCS (or newborn calf serum [NBS], which, if tested for non-toxicity, may be used as a cheaper alternative). If the effect of antibody binding on the behavior of the membrane protein is unknown, then all incubations should be carried out at 4°C (float plates on ice bath and precool diluents). Monolayers of cells vaiy widely m their adhesion to plastic, and also, they may roundup after prolonged incubation at 4°C owing to depolymenzation of microtubules (see Note 7). 

Another opportunity for change might be decorative. If labels are used and need to be retained then the method of printing should be discussed with the label manufacturer and examined in terms of print effect versus cost. The label substrate can help to create an impression of quality through the use of plastic, either in conjunction with paper in laminate form or in monolayer form. Whether the labels are pre-cut or reel-fed will also impact on whether the label can be a shaped patch label or is wrapped around the package. 

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