Core-shell type architecture

Sequential hydroformylation/reductive amination of dendritic perallylated polyglycerols with various amines in a one-pot procedure to give dendritic polyamines in high yields (73-99%). Furthermore, the use of protected amines provides reactive core-shell-type architectures after deprotection. These soluble but membrane filterable multifunctional dendritic polyamines are of high interest as reagents in synthesis or as supports in homogeneous catalysis as well as nonviral vectors for DNA-transfection (Scheme 18) [65]. 

Encapsulation systems for bioactive compounds may take different configurations and architectures, depending on materials, fabrication process, dispersion medium, as well as interaction with the payload. However, despite an ultimate classification of encapsulation systems being difficult. Figure 37.2 tries to provide approximate categories, identifying two broad classes of systems, one pertaining to matrix type and the other to core and shell type. 

There are a variety of different types of particle that can be synthesized using microfluidics and the exact fluidic format used defines the flow characteristics of the synthesis environment which needs to be carefully matched to the synthetic requirements of each particle type. Broadly speaking, the main particle types of interest include monodisperse microgels, metal nanoparticles and nanocrystals, core-shell particles, microemulsions, and microcapsules. Typically these particles should be homogeneous in size and are composed either of an organic polymer matrix or a metal or metal mixture at the micron or nanometer scale. In addition to these simple particle architectures, we may also consider more complex particles composed of multiple layers or components such as core-shell particles or using a central cavity to encapsulate small molecules, proteins, or other particles, and these are called microcapsules. 

Fig. 1 Four types of semiconductor-based composite architectures (a) semiconductor/matrix (b) layered configuration of two semiconductors, A and B (c) coupled semiconductors (d) core-shell geometry SC denotes the semiconductor [12]...

Pis. 27 Core-shell architecture of the PAMAM corerfullerene shell [S-l (H-5)3o] type of nanocompound. Z mdieates terminal -NH2 or -NH- groups on the PAMAM dendrimer core component of the core-shell nanocompound [177]... 

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