**Author details**

278 Practical Applications in Biomedical Engineering

acids, and fatty acids [78].

**6. Conclusion** 

Peroxisomes are small membrane-enclosed organelles that contain enzymes involved in a variety of metabolic reactions, including several aspects of energy metabolism. Peroxisomes contain at least 50 different enzymes, which are involved in a variety of biochemical pathways in different types of cells. Peroxisomes were defined as organelles that carry out oxidation reactions leading to the production of hydrogen peroxide. A variety of substrates are broken down by such oxidative reactions in peroxisomes, including uric acid, amino

Biodistribution, targeting and excretion can also be investigated by radiolabeled poly(2 alkyl-2-oxazolines). Authors used 111In-labeled polymers to study the distribution and excretion of such polymers in mice [79]. Similarly, 125I-labeled 2-oxazoline-based copolymers were examined after their intravenous administration to mice, and their biodistribution was assessed [80]. Beside the described visualization techniques, other modern methods such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force

The aim of this chapter was to survey the currently used experimental methods for evaluation of polymeric materials in biological systems concerning various methods for biocompatibility, immunological, bioimmunological and immunotoxicological assessment. This covers practical aspects throughout assay development and specific methodology adjustment. Decisive stages in development and application of these methods and practical suggestions are discussed. Such kind of research is essential due to enormous progress in

Among a number of polymers suitable for the use in medicine, poly(2-oxazolines) belong to polymeric materials with a great potential for different biomedical application. Their possible application areas in biological and medicinal contexts were reported. Especially the drug delivery, gene therapy and tissue engineering belong to the principal areas of their applications. Nowadays, several immunobiological and immunotoxicological methods were employed for the assessment of their biocompatibility and bioavailability. *In vitro* cytotoxicity of poly(2-oxazolines) was evaluated mainly by colorimetric MTT assay. However, other laboratory methods, like XTT, TB, SRB or WST assays, can be also used. All published results proved high biocompatibility of poly(2-oxazolines). Additionally, polymers prepared by cationic polymerization of 2-alkyl-2-oxazolines behave as "stealth" materials. This behaviour was confirmed by several independent immunological methods. Selected techniques as flow cytometric evaluation of phagocyte functions, immunocytometric determination of TH1/TH2/TH17 cytokines and ELISpot evaluation of cytokine producing cells comprise novel approaches to characterise immunomodulation of basic functions of immune competent cells targeted with poly(2-oxazolines). Last part of the

microscopy (AFM) or tomography are available for the analysis of biodistribution.

the development of polymeric materials for different biomedical applications.

chapter summarized *in vitro* and *in vivo* visualisation methods.

Juraj Kronek, Zuzana Kroneková and Jozef Lustoň *Polymer Institute, Centre of Excellence GLYCOMED, Slovak Academy of Sciences, Bratislava, Slovakia* 

Ema Paulovičová and Lucia Paulovičová

*Institute of Chemistry, Centre of Excellence GLYCOMED, Slovak Academy of Sciences, Bratislava, Slovakia* 
