Polymers proteins and

Figure 2), consisting of residual polymer, protein, and lipid not incorporated in the microspheres. 

Separation of mixtures of compounds with high molecular weights, such as synthetic polymers, proteins, and other biopolymers whose retention changes markedly for small changes in the composition of mobile phases... 

Thanou, M., and Duncan, R. Polymer-protein and polymer-drug conjugates in cancer therapy. Curr. Opin. Invest. Drugs 4(6) 701—709. 2003. 

This chapter relates to some recent developments concerning the physics of out-of-equilibrium, slowly relaxing systems. In many complex systems such as glasses, polymers, proteins, and so on, temporal evolutions differ from standard laws and are often much slower. Very slowly relaxing systems display aging effects [1]. This means in particular that the time scale of the response to an external perturbation, and/or of the associated correlation function, increases with the age of the system (i.e., the waiting time, which is the time elapsed since the preparation). In such situations, time-invariance properties are lost, and the fluctuation-dissipation theorem (FDT) does not hold. 

Size exclusion chromatography (SEC) separates molecules based on differences in their hydrodynamic volume (or size). For this reason, SEC has become a standard technique for determining molecular weight distributions of polymer samples. Common separation applications include polymer, protein, and nucleic... 

The osmotic pressure for solutions of polymers, proteins, and other large molecules increases strongly with concentration, as shown in Figure 9.12 for whey proteins. This can make An a significant portion of AP even when the osmotic pressure of the feed solution is negligible. 

Like all polymers, proteins and DNA are composed of a sequence of repeating units that interact at various levels to produce the active structure. Although the primary structure of DNA does largely determine its physical and biological properties, that of proteins is of minimal use in determining the desired active structure. This section is not intended to replace a biochemistry textbook, but it provides the basic information necessary to understand how the molecular structure of proteins and plasmid DNA differ, and how this impacts macromolecular stability in a general sense. 

Optical activity of natural products may depend on chemical factors such as asymmetric carbon atoms, restricted rotation, etc. These may be termed primary structural features. There are also secondary structures, e.g., helices or random coils, that may confer chirality to a natural product. Optical rotatory dispersion (ORD, i.e., rotation of plane-polarized radiation over a range of wave-lengths usually from approximately 200 to approximately 500/im) has been used in studies of the conformations of many different molecules, including polymers, proteins, and polypeptides [90]. 

A foam is a dispersion of a gas in a liquid or a solid. The formation of foam relies on the surface activity of the surfactants, polymers, proteins, and colloidal particles to stabilize the interface. Thus, the foamability increases with increasing surfactant concentration up to critical micelle concentration because above critical micelle concentration, the unimer concentration in the bulk r ains nearly constant. The structure and molecular architecture of the foam is known to influence foam-ability and its stability. The packing properties at the interface are not excellent for very hydrophilic or very hydrophobic drug. The surfactant promoting a small spontaneous curvature at interface is ideal for foams. Nonionic surfactants are the most commonly used one. The main advantage with foams is its site-specific delivery and multiple dosing of the drug. ... 

On the other hand, biomedical applications are very limited in both in vivo and in vitro conditions due to the high toxicity of these nanoparticles to the cells (You-yu et al., 2014). Therefore, nanoparticles are coated with compounds, such as natural polymers (proteins and carbohydrates) (Nair et al., 2010), synthetic organic polymers (polyethylene glycol), polyvinyl alcohol, poly-L-lactic acid. 

The method of X-ray diffraction is widely used for the determination of the structures of molecular soUds (i.e. solids composed of discrete molecules) and of non-molecular solids (e.g. ionic materials). As the technique has been developed, its range of applications has expanded to include polymers, proteins and other macromolecules. The reason that X-rays are chosen for these experiments is that the wavelength (p lO m) is of the same order of magnitude as the internuclear distances in molecules or non-molecular solids. As a consequence of this, diffraction is observed when X-rays interact with an array of atoms in a soUd (see below). 

Dipoles and Polarization Phenomena. Many molecules do not carry formal electrical charges, so that their mutual interactions do not involve the direct coulombic interactions discussed above. However, if one examines the structures of many useful chemical species, including polymers, proteins, and drugs, it is apparent that they often include bonds that can impart an overall polar nature to the molecule as permanent dipoles, or they can be polarized by the effect of neighboring electric fields producing induced dipoles. The presence of permanent or induced dipoles means that the molecules can become involved in specific interactions with charged species, other dipoles, or nonpolar molecules, and those interactions can significantly affect the physical characteristics of the system. 

Studies on adsorbed species and the surface chemistry of oxides in their normal state have been carried out to a great extent by high resolution solid-state NMR [17], especially due to the widely growing area of heterogeneous catalysis. A relatively small contribution is found for the use of NMR for probing adsorption phenomena in colloidal oxides, and it is only briefly discussed here. Colloidal systems such as organic polymers, proteins, and microemulsions are relatively well covered in the literature and therefore are out of the seope of this ehapter. Metal eolloids are not eonsidered either. 

Not only the molecular mass but also the conformation of organic molecules plays an important role in their retention by membranes clearly the retention depends on the molecular shape and increases with the rigidity of the molecule. Similar results have been obtained for synthetic water-soluble polymers, proteins, and other biological macromolecules. It has been shown that the nature of the solvent, the nature and concentration of the electrolytes or complexable ions, and an increased concentration of polymer at the membrane surface due to concentration polarization may modify the conformation of the polymer and therefore its retention. 

One of the key features of the RAFT polymerization is the potential functionalization capability by carefully selecting the functional substituent Z of the RAFT agent (see Fig. 2.25). Quemener et al. [110] developed a clickable (1,3-dipolar cycloaddition) azide and alkyne functionalized RAFT agents and weU-defined block polymers of vinyl acetate and styrene were prepared by combining RAFT polymerization and click chemistry. A similar combination of RAFT and click chemistry has been successfully evaluated to generate various block polymers for polymer- protein and drug conjugations [111]. 

SynChropak, also sold as Aquapore and Blo-Sil GFC, Is applied in the SEC separation of water-soluble polymers, proteIns and pectins . The SynChropak GPC 100 Is compared with other commercial products in ref. 44. 

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