Delivery vehicle

Phospholipid molecules form bilayer films or membranes about 5 nm in thickness as illustrated in Fig. XV-10. Vesicles or liposomes are closed bilayer shells in the 100-1000-nm size range formed on sonication of bilayer forming amphiphiles. Vesicles find use as controlled release and delivery vehicles in cosmetic lotions, agrochemicals, and, potentially, drugs. The advances in cryoelec-tron microscopy (see Section VIII-2A) in recent years have aided their characterization [70-72]. Additional light and x-ray scattering measurements reveal bilayer thickness and phase transitions [70, 71]. Differential thermal analysis... 

The development vehicle used to create and test the rule base must be as flexible as possible, allowing easy alterations and expansion of the rule base with whatever displays can convey the most information. The delivery vehicle, however, should be virtually transparent to the user, conveying only as much information as needed to solve the problem at hand. Self-tuning controllers can perform their task without explicitlv informing users, but their output and status is available on demanci, and their operation may be easily limited or interrupted. 

Equipment or Base Cost The total cost of the main-plant items is generally used as the base cost. Again, care must be taken with equipment costs which may be quoted as installed (INST), delivered to site (DEL), or free on board the delivery vehicle at the place of manufacture or other specified location (FOB). 

Two main benefits accrue from a systems approach to materials handling and packaging. First, a trade-off of investment and operating costs is made possible nigher costs in some parts of a system become permissible in return for much lower costs in other parts. The net result is usually the lowest overall cost. If this is not the case, the reasons for incurring the higher costs can be identified and justified. The second benefit is that customers are not offended by ill-conceived packages, delivery vehicles, or product characteristics. 

MacPhee, M., Singh, M., Brady, R., Akhyani, N., Liau, G., Lasa, C., Hue, C., Best, A. and Drohan, W. Fibrin sealant A versatile delivery vehicle for drugs and biologies. In Sierra, D. and Sallz, R. (Eds.), Surgical Adhesives and Sealants. Current Technology and Applications. Technomic, Lancaster, PA, 1996, pp. 109-120. 

Alternatives to coal and hydrocarbon fuels as a source of power have been sought with increasing determination over the past three decades. One possibility is the Hydrogen Economy (p, 40), Another possibility, particularly for secondary, mobile sources of power, is the use of storage batteries. Indeed, electric vehicles were developed simultaneously with the first intemal-combustion-cngined vehicles, the first being made in 1888. In those days, over a century ago, electric vehicles were popular and sold well compared with the then noisy, inconvenient and rather unreliable peU ol-engined vehicles. In 1899 an electric car held the world land-speed record at 105 km per hour. In the early years of this century, taxis in New York, Boston and Berlin were mainly electric there were over 20000 electi ic vehicles in the USA and some 10000 cars and commercial vehicles in London. Even today (silent) battery-powered milk delivery vehicles are still operated in the UK. These use the traditional lead-sulfuric acid battery (p. 371), but this is extremely heavy and rather expensive. 

Electric vehicle (EV) is an abbreviated term for battery electric vehicle, which is a vehicle that uses energy from a batteiy to operate an electric motor that rotates the wheels. Throughout the twentieth century, a wide array of electric cars, trucks, buses, bikes, and scooters have been developed. However, except for the golf cart and special delivery vehicles, none has experienced any sustained commercial success. 

Crude oil is processed at oil refineries, generally located around coastal areas, and then transferred to a nationwide network of oil fuel terminals, from where it is distributed to customers. Road delivery vehicles, rail tank wagons or coastal tankers - depending on the location of the customer s storage installation - can make fuel supplies to the customer. 

External to the boiler house, provision for the storage and handling of solid and liquid fuel is required with access for delivery vehicles. With some small boilers such as electrode or steam-coil generators, where the boiler only serves a single item of plant or process, it is practical to install them immediately adjacent to that process. The electrode boiler is eminently suitable here as no combustion gases are produced. 

Immunological reactions of the host to either the delivery vehicle or its cargo are another concern. The host immune response might not only eliminate the vector... 

Dendrimer micelles of this type have been formulated as drug delivery vehicles. Dendrimers with a hydrophobic interior have been used to entrap a hydrophobic drug such as indomethacin. This is retained because of the hydrophilic periphery containing ethylene glycol functional groups, and is released slowly because of the collapsed configuration of the interior, through which molecular diffusion is obstructed. 

Oehlke and coworkers have described the cellular uptake properties of a simple a-hehcal amphipathic model peptide sequence (Lys-Leu-Ala-Leu-Lys-Leu-Ala-Leu-Lys-Ala-Leu-Lys-Ala-Ala-Leu-Lys-Leu-Ala) in the context of a drug delivery vehicle [72]. On the basis of the data presented, it was proposed that non-endocytosis mechanism(s) were involved in the uptake into mammalian cells. The similarity between our b2 aPNA-sequence to that of this amphipathic model peptide makes it tempting to suggest that a similar uptake mechanism is involved in the cellular uptake of aPNAs. Further experimentation is necessary to test this hypothesis. 

Our initial bioavailabihty experiments indicate that cationic aPNAs are readily intemahzed by cells without any additional delivery vehicle and that they do not affect ceU viabihty. We are currently examining aPNA internalization with other cell types as weU as the intracellular localization of aPNAs. 

Lucas, P. A., Laurencin, C., Syftestad, G. T., Domb, A., Goldberg, V. M., Caplan, A. I., and Langer, R., Ectopic induction of cartilage and bone by water-soluble proteins from bovine bone using a polyanhydride delivery vehicle, J. Control. Rel. In Press. 

ELP-based triblock copolypeptides have also been used to produce stimulus-responsive micelles, and Chaikof and coworkers envisioned the possible application of these micelles as controlled drug delivery vehicles. These amphiphilic triblock copolymers were constructed from two identical hydrophobic ELP endblocks and a hydrophilic ELP midblock. Below the transition temperature, loose and monodispersed micelles were formed that reversibly contracted upon heating, leading to more compact micelles with a reduced size [90]. 

Historically, after the development of oligopeptide-based vesicles, several groups developed and characterized vesicles using polypeptide hybrid systems consisting of polypeptide and synthetic polymer blocks [17-19]. Soon thereafter, vesicles formed entirely from polypeptides, such as poly(L-lysine)-h-poly(L-leucine) and poly(L-lysine)-h-poly(L-glutamate), were developed [20, 21]. This review will focus on recent developments in the formation of vesicles composed of polypeptide hybrid or polypeptide systems, as well as the potential promise of these systems as effective dmg delivery vehicles. A specific example of a polypeptide-based vesicle is shown in Fig. 1, where the hydrophobic segment is a-helical and the hydrophilic segment is a random coil. 

Such hydrogels have been suggested to be suitable for biotechnological applications (DNA delivery vehicles, cell encapsulation) [28]. Recently, amphiphilic dibock copolypeptide hydrogels of KigoL2o were used in an in vivo study where the hydrogels were injected into the mouse forebrain. Evaluation of samples displayed substantial tissue integration with little or no detectable toxicity in the central nervous system [148]. 

Young S, Wong M, Tabata Y et al (2005) Gelatin as a delivery vehicle for the controlled release of bioactive molecules. J Control Release 109 256-274... 

Acute oral LDjgS have been determined for mice (2,402 mg/kg) (Tucker et al. 1982) and rats (7,208 mg/kg) (Smyth et al. 1969). In a study in which pregnant rats were treated by gavage with trichloroethylene in com oil on gestation days 6-15, 2 of 13 died at 1,125 mg/kg/day, while all survived at 844 mg/kg/day (Narotsky etal. 1995). The lethality of trichloroethylene may be related to the delivery vehicle. Administration of trichloroethylene in an aqueous Emulphor vehicle proved to be more lethal but less hepatotoxic than similar administration of trichloroethylene in com oil during a 4-week exposure period (Merrick et al. 1989). Further... 

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