Biological characterization

Biological characterizations are performed using either a Petri dish (in vitro) or within the animal body (in vivo). The details of a range of frequently used investigational techniques are provided in the following sections. 

1 In Vitro Evaluation Methods Simulated Body Fluids and Cell Culture 

Cell culture testing is used widely in vitro to evaluate the biocompatibihty of HA samples. For this, several osteoblast cell lines have been developed to assess biomaterials performance in vitro, including a murine osteoblastic cell hne (MC3T3-El) [121], a human osteoblastic precursor cell line (OPCl) [122] and a human osteoblast cell line (hFOB 1.19) [123]. Osteoblast cells interact differently with material structures, depending on the combinations of chemical, structural and environmental variables. The biocompatibility of HA surfaces can be assessed using ceU-material interaction studies such as attachment, proliferation and differentiation. Cell proliferation on HA samples is normally investigated with a mitochondrial (MTT) assay, which permits the quantitative estimation of the number of living cells on a material. 

optical and electron microscopy are used to observe cell morphology and to understand cell attachment and differentiation on materials. 

Confocal scanning microscopy is used to assess the expression of specific osteoblast proteins, such as ALP and osteopontin (OPN). 

---

Biological characterization includes toxicological studies, dose relationships, routes of adininistration, identification of side effects, and absorption, distribution, metaboHsm, and excretion patterns. If the results are stiU acceptable, product formulation and dosage form are developed. The product should be pleasing to the patient and thus may contain flavoring and colorants. 

Plewa Ml, ED Wagner, SD Richardson, AD Thurston, Y-T Woo, AB McKague (2004) Chemical and biological characterization of newly discovered iodoacid drinking water disinfection byproducts. Environ Sci Technol 38 4713 722. 

Maule, A.G., Shaw, C., Bowman, J.W., Halton, D.W., Thompson, D.P., Thim, L., Kubiak, T.M., Martin, R.A. and Geary, T.G. (1995a) Isolation and preliminary biological characterization of KPNFIRFamide, a novel FMRFamide-related peptide from the free-living nematode, Panagrellus redivivus. Peptides 16, 87-93. 

Khazanov, E. Barenholz, Y., Gibson, D., Najraeh, Y. Novel apoptosis-including trans-platinum piperidine and piperazine derivatives Synthesis and biological characterization. J. Med. Chem. 2002, 45, 5189-5195. ... 

Brus C, Petersen H, Aigner A, Czubayko F, Kissel T (2004) Physicochemical and biological characterization of polyethylenimine-graft-poly(ethylene glycol) block copolymers as a delivery system for oligonucleotides and ribozymes. Bioconjug Chem 15 677-684... 

Wang, Y.-S., Youngster, S., Grace, M., Bausch, J., Bordens, R., and Wyss, D.F. 2002. Structural and biological characterization of pegylated recombinant interferon alpha-2b and its therapeutic implications. Advanced... 

Biological characterization of the nanoparticles was carried out by monitoring in vitro interactions with hepatocytes isolated from rat liver [12], Haemagglutination inhibition test of erythrocytes with ricine agglutinin (RCA120) was carried out [13]. The fluorescence of the hepatocytes incubated with the FlTC-labeled nanoparticles was determined by means of a FACS Star Becto-Dickinson instmment. 

Boopathi E, Rao KS (1999) A Siderophore from Pseudomonas putida Type Al Structural and Biological Characterization. Biochim Biophys Acta 1435 30... 

Haag H, Fiedler HP, Meiwes J, Drechsel H, Jung G, Zahner H (1994). Isolation and Biological Characterization of Staphyloferrin B, a Compound with Siderophore Activity from Staphylococci. FEMS Microbiol Lett 115 125... 

Wang W, Chi Z, Liu G., Buzdar MA, Chi Z, Gu Q (2009) Chemical and Biological Characterization of Siderophores Produced by the Marine-derived Aureobasidium pullu-lans HN6.2 and its Antibacterial Activity. Biometals 22 965... 

Ahlberg M, Berghem L, Nordberg G, et al. 1983. Chemical and biological characterization of emissions from coal- and oil-fired power plants. Environ Health Perspect 47 85-102. 

Westerholm R, Egebaeck K. 1991. Impact of fuels on diesel exhaust emissions. A chemical and biological characterization. National Environmental Protection Agency Solna, Sweden. 

The cannabinoid-type psychoactive principles of marijuana Cannabis sativa L.), have been of interest to pharmacologists for many years. The biological characterization of the major euphoriant principle, (—j-A - wr-tetrahydrocannabinol (THC) (20), has led to an understanding of the molecular mechanisms of these compounds, and ultimately enabled the characterization of the cannabinoid receptor This... 

Heinke, R., Spannhoff A., Huda, E., Meier, R., Jung, M. and Sippl, W. (2009) Virtual screening and biological characterization of histone methyltransferase inhibitors PRMTl. ChemMedChem, 4, 69-77. 

Wang, Y. et al. (2002). Structural and biological characterization of PEGylated recombinant interferon-a2B and its therapeutic implications. Adv. Drug Delivery Rev. 54(4), 547-570. 

In summary, based on the observation of divergent in vitro and in vivo SAR, a new class of cholesterol-lowering compounds was discovered. Subsequent biological characterization of the first generation lead compound SCH-48461, limited the site of action to be at or near the intestinal villi, with the most probable mechanism being the inhibition of luminal absorption. An SAR optimization based solely on an in vivo assay and without biochemical characterization of the molecular target led to the design of ezetimibe (1). 

B. Franzen, M. Jansson, J. A. Gustafsson, K. E. Egeback, and G. Tejle, Chemical and Biological Characterization of Organic Material from Gasoline Exhaust Particles, Environ. Sci. Technol., 19, 43-50 (1985). 

Ramdahl, T., I. Alfheim, S. Rustad, and T. Olsen, Chemical and Biological Characterization of Emissions from Small Residential Stoves Burning Wood and Charcoal, Chemosphere, 11, 601-611 (1982a). 

Schuetzle, D T. E. Jensen, and J. C. Ball, Polar Polynuclear Aromatic Hydrocarbon Derivatives in Extracts of Particulates Biological Characterization and Techniques for Chemical Analysis, Enriron. Int., 11, 169-181 (1985). 

J. Ondo, A. Fong, and S. Lum, The Chemical and Biological Characterization of Particulate Matter as Part of an Epidemiological Cancer Study, J. Aerosol Sci., 12, 208-212 (1981). 

K. Gragg, Chemical and Biological Characterization of Particulate-, Semi-volatile-, and Gas-Phase-Associated Compounds in Diluted Heavy-Duty Diesel Exhausts A Comparison of Three Different Semi-volatile-Phase Samplers, Environ. Sci. Technol., 25, 332-338 (1991). 

The physiochemically and biologically characterized proteins and peptides are further formulated and subject to stability studies. The goal of these studies is to develop a unique combination of excipients, solution pH, buffer, and container that will produce an optimum dosage form. Biopharmaceutical formulations should be... 

In conclusion, the process allowed early recognition of lead novelty and has become an effective filtering function after a preliminary dereplication. In addition, the procedure provided adequate amounts of pure metabolites which allow proper chemical and biological characterization. The operation is semiautomated which makes leads generation faster, cheaper, and more efficient. 

More than in the past, a systematic setting of priorities is advocated by the authorities. Development takes place by two approaches (1) an effect-oriented approach and (2) a source-oriented approach. These approaches are based on two issues (1) Which effects are caused by which products-processes (2) Which sources emit-discharge which products In this regard, the scheme from emission to toxicological effect must be traced and concentration techniques must be developed. The close connection between chemical and biological characterization must be strongly stressed in this respect. 

---