Drug delivery systems peptide amphiphiles

Biological molecules do show regularity at the level that is not obtained with synthetic polymers. Protein folding is a perfect example, but it is not yet well understood. Therefore, protein-based 3D drug delivery systems are difficult to design. However, small peptides with amphiphilic structure (e.g., V6K, where six valines form hydrophobic part and lysine is the hydrophilic end group) can assemble... 

Figure 73 Representative 3-D nanostructured scaffolds for bone-specific drug delivery systems, (a) Electrospun sitk scaffold with BMP-2 loaded, scale bar=5 pm (reprinted from Ref. [86] with permission) (b) Self-assembled peptide-amphiphile (PA) nanofibers network, scale bar= 1 mi (reprinted from Ref. [87] with permission) (c) Nanocrystalline apatite modified poly(lactide-co-glycolide) (PLAGA) microsphere scaffolds, scale bar=2pm (reprinted from Ref. [88] with permission) and (d) poly(L-lactic acid) (PLLA) nanofibrous scaffolds incorporated with poly(lactic-co-glycolic acid) (PLGA) nanospheres, scale bar=2 pm (reprinted from Ref. [89] with permission).

Li) and reverse (L2) curvatnre respectively, can be swollen by oil and water to form water/oil/amphiphile ternary or pseudo-ternary systems. These systems can be used for different types of studies, e.g. structural investigations of an immobilized peptide or protein, drug delivery systems, and also micellar catalysis. A variety of ternary systems based on water, oil, and amphiphile mixtures have been investigated. Thermodynamically stable microemulsions, e.g. Li or L2 monophasic regions, may form spontaneously provided that the amphiphilic molecules located at the polar-apolar interface cause a substantial decrease of the oil-water interfacial tension (Yo/w) according to the typical equation ... 

Recently, novel polymeric and peptide self-assembling systems have been developed for drug delivery. These carriers mimic the characteristics of conventional Upid systems and, in some cases, demonstrate improved drug delivery qualities. In this case, diblock copolymers are commonly used to construct micellar assanbUes. Self-assembly of block copolymers is often spontaneous and can be performed in the presence of small molecules that form micelles encapsulated with drugs, with diameters up to hundreds of nanometers (Lee and Yuk 2007 Branco and Schneider 2009). In addition to micelles, amphiphilic block copolymers can self-assemble into vesicles in water. Polymersomes have been used for delivery of small hydrophobic... 

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