Cell growth vehicles

Like small amphiphile nanotubes [14], block copolymer nanotubes should have potential applications in controlled deUvery and release [97,98], in encapsulation [99], and in nanoelectronics [100] etc. Although there have been reports on laboratory use of block copolymer nanofibers as vehicles for drug delivery [101], as scaffolds for cell growth [88,102], as precursors for ceramic magnetic nanowires [103,104], and as precursors for carbon nanofibers [105,106[, practical applications of block copolymer nanotubes have not been reported. This is probably due to the difficulty in making such structures. Their preparation from the self-assembly of block copolymers and interests from industry will likely change the scenery of nanotube appUca-tions in the futme. 

Bioresorbable materials have been administered in preclinical studies either alone or as delivery vehicles for cells, growth factors, and biological moieties. The major advantages of these systems can be summarized as delivery of drugs at a constant rate, drug protection, drug control pharmacokinetics, minimization of possible side effects, better efficacy, and enhanced patient compliance [37] (Fig. 19.3). 

The bacterial culture converts a portion of the supplied nutrient into vegetative cells, spores, crystalline protein toxin, soluble toxins, exoenzymes, and metabolic excretion products by the time of complete sporulation of the population. Although synchronous growth is not necessary, nearly simultaneous sporulation of the entire population is desired in order to obtain a uniform product. Depending on the manner of recovery of active material for the product, it will contain the insolubles including bacterial spores, crystals, cellular debris, and residual medium ingredients plus any soluble materials which may be carried with the fluid constituents. Diluents, vehicles, stickers, and chemical protectants, as the individual formulation procedure may dictate, are then added to the harvested fermentation products. The materials are used experimentally and commercially as dusts, wettable powders, and sprayable liquid formulations. Thus, a... 

The conclusions above are all based on the assumption that no shifts in export-import relations occur (e.g., same market share of fuel-cell vehicles for European car manufactures as today for conventional vehicles). However, the mid-term employment effects in automotive sectors could be drastic if the assumption of similar competitiveness is rejected for hydrogen technologies. It could also be assumed that in such a case relevant negative consequences for GDP would occur. However, with great efforts in the field of hydrogen, exports might be possible with additional positive effects for employment and growth. 

The battery industry has seen enormous growth over the past few years in portable, rechargeable battery packs. The majority of this surge can be attributed to the widespread use of cell phones, personal digital assistants (PDA s), laptop computers, and other wireless electronics. Batteries remained the mainstream source of power for systems ranging from mobile phones and PDA s to electric and hybrid electric vehicles. The world market for batteries was approximately 41 billion in 2000, which included 16.2 billion primary and 24.9 billion secondary cells. 

---