Biomedical applications chemical synthesis

Finally, for practical reasons it is useful to classify polymeric materials according to where and how they are employed. A common subdivision is that into structural polymers and functional polymers. Structural polymers are characterized by - and are used because of - their good mechanical, thermal, and chemical properties. Hence, they are primarily used as construction materials in addition to or in place of metals, ceramics, or wood in applications like plastics, fibers, films, elastomers, foams, paints, and adhesives. Functional polymers, in contrast, have completely different property profiles, for example, special electrical, optical, or biological properties. They can assume specific chemical or physical functions in devices for microelectronic, biomedical applications, analytics, synthesis, cosmetics, or hygiene. 

CPs can be fabricated through a variety of routes which are classified as either predominantly electrochemical or chemical. While electrochemical synthesis has been more widely used for preparing nanoscale CP thin films for biomedical applications, chemical polymerization can produce large quantities of CP thick films or colloidal dispersions at low cost. Despite these advantages, chemical techniques have found relatively little application in biomedical applications. The advantages and disadvantages of electrodeposition and chemical synthesis are summarized in Table 18.2. 

Kushchevska N.F. Physico-chemical conditions of synthesis of nanocomposite feiTomagnetic powders for biomedical applications. Autoref. diss. Dr. Technical Sciences / K. Scientific world, 2003. - 39 p. 

The past two decades have produced a revival of interest in the synthesis of polyanhydrides for biomedical applications. These materials offer a unique combination of properties that includes hydrolytically labile backbone, hydrophobic bulk, and very flexible chemistry that can be combined with other functional groups to develop polymers with novel physical and chemical properties. This combination of properties leads to erosion kinetics that is primarily surface eroding and offers the potential to stabilize macromolecular drugs and extend release profiles from days to years. The microstructural characteristics and inhomogeneities of multi-component systems offer an additional dimension of drug release kinetics that can be exploited to tailor drug release profiles. 

After the first successful attempts in 1928 to identify the active biochemicals found in antibacterial molds, followed the rediscovery of penicillin by Fleming, identification of its chemical structure by Hodgkin, and subsequent synthesis by Chain, Heatley, and Florey, which led to the commercial production of penicillin in the mid 1940s [1], Since then, other families of (3-lactam antibiotics have been developed [2, 3], and their massive use worldwide continues to be a forefront line of action against infectious pathogens [4-6]. In recent years, (3-lactams have found other biomedical applications, such as inhibitors of serine protease ([7, 8] for a review, see [9]) and inhibitors of acyl-CoA cholesterol acyltransferasa (ACAT) [10]. Encouraged by their bioactivity, the synthesis and chemistry of (3-lactam antibiotics have been the focus of active research, and chemical modification of some basic structures available from biosynthesis (semisynthetic approaches) as well as the discovery of fully chemical routes to de novo synthesis of (3-lactam... 

Similarly to their natural counterparts (enzymes, antibodies, and hormone receptors), MIPs have found numerous applications in various areas. They have been used as antibody mimics in immunoassays and sensors and biochips as affinity separation materials and for chemical and bioanalysis, for directed synthesis and enzyme-like catalysis, and for biomedical applications. Concerning their commercialization, there has been great progress during the past decade, in particular in the... 

Aliphatic polyesters are an attractive class of polymer that can be used in biomedical and pharmaceutical applications. One reason for the growing interest in this type of degradable polymer is that their physical and chemical properties can be varied over a wide range by, e.g., copolymerization and advanced macro-molecular architecture. The synthesis of novel polymer structures through ringopening polymerization has been studied for a number of years [1-5]. The development of macromolecules with strictly defined structures and properties, aimed at biomedical applications, leads to complex and advanced architecture and a diversification of the hydrolyzable polymers. 

Polyanhydrides are a class of bioerodible polymers that have shown excellent characteristics as drug delivery carriers. The properties of these biomaterials can be tailored to obtain desirable controlled release characteristics. Extensive research in this promising area of biomaterials is the focus of this entry. In the first part of the entry, the chemical structures and synthesis methods of various polyanhydrides are discussed. This is followed by a discussion of the physical, chemical, and thermal properties of polyanhydrides and their effect on the degradation mechanism of these materials. Finally, a description of drug release applications from polyanhydride systems is presented, highlighting their potential in biomedical applications. 

Calcium phosphate apatite formulations that are available commercially from different suppliers exhibit high chemical variability. Thus, manufacturers of apatite for biomedical applications often produce their own powder. Furthermore, synthesis enables a range of chemical substitutions, crystal sizes, shapes and forms (separate crystals or cements, as discussed in the next section). Various reviews cover synthesis methods (Narasaraju and Phebe 1996, Le Geros et al. 1995, Orlovskii and Barinov 2001). 

In this chapter, we first discuss the chemical and physical properties of chitosan, including the synthesis, modification, molecular structure, characterization, and structure-property relationship. Second, we review the topics of biocompatibility, biodegradability, and antimicrobial activity of chitosan. These properties make chitosan a potential biomaterial for many biomedical applications. 

Nanoparticle fabrication includes methods such as solvent evaporation, spontaneous emulsification, solvent diffusion, salting out/emulsification diffusion, and polymerization techniques [24]. The synthesis method can greatly impact the particle s physical, chemical, and biological properties and the dispersion and stability of the particles, which are important considerations in biomedical applications. The nanoparticle size and shape is of great importance because the internalization, circulation, distribution, and targeting aspects of the system can be affected by these characteristics [5]. 

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