Bioassays future developments

It should be also noted that the field of smart polymer surfaces is not limited to the macromolecular structures presented in the first part of this chapter. Although some classic stimuli-responsive polymers such as PNIPAM or poly(acrylic acid) have been studied for several years, new exciting options are reported every week in the polymer literature. For instance, the synthesis of chemo- and bioresponsive polymers is a topic in full expansion [9], Thus, new developments in the fields of bioassays and biosensors may be expected in the near future. For instance, more advanced surface concepts (e.g., multiresponsive behaviors, signal cascades) can be anticipated with reasonable certainty. 

With pressures from the animal rights movement, an impetus has been generated for the development of in vitro and/or computer models to reduce the level of in vivo testing. In the seventies, the hope of the future was placed in what was then considered a potential replacement technique for the lifetime rodent bioassay for cancer assessment—the short-term mutagenicity tests, particularly the Ames Evaluation (16). Brusick (17) has shown that the correlation between a positive mouse bioassay and a positive rat bioassay for a selected group of materials is no better than the... 

The data from Enslein s Model show that a good match with the rodent bioassays is possible for organics upon which the SAR model is based. The SAR model is ineffective for metals, simple hydrocarbons like benzene, mixtures and hormones. Within these limits, the prediction is 100%. Considering the reliability of rodent and in vitro bioassays to predict the human response, it is possible, with continued development, that in the future, SAR may become a powerful tool to supplement our other sources of toxicological information. 

The use of medicinal plants for the treatment of epilepsy and convulsive disorders dates back to prehistoric times. Several plants that were reputed to possess antiepileptic properties in different folklore cultures have been found to contain active ingredients when tested with modem bioassays for detecting anticonvulsive activities. This provides justification for their use in many different indigenous medicinal systems. The activity of many other plants however remains to be scientifically established. Several such plants have been listed in order to promote further research with the hope that better medicines may be developed for treatment of epilepsy in the future. 

Bioassays with purified proteins provide useful information for broadly determining the areas that require further study. Information obtained may also assist with decisions about how appropriate a particular genetic modification will be for a particular plant species. In the future this methodology could usefully be extended to look at other transgene products under development for expression in GM plants. 

To some degree, the advantages of label-free detection are remarkable and are summarized in Table 12.1. As shown in the table, label-free is one of the most effective methods to make detection simpler and more convenient. However, its maturation requires greater effort and appears likely to escalate as a popular process in several traditional and new detection techniques. Undoubtedly, the development of aptamers endows this technique with more potential in future bioassays, due to the unique properties of aptamers. 

Different bioassays using animals were used in the past to evaluate the safety and efficacy of finished products but nowadays, authorities encourage researchers to develop alternative in vitro methods that can substitute all the animal assays. The aim is both to avoid or to reduce the number of these experiments at the present time and to completely forbid them in the near future. 

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