Chemistry Reference
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The concept of repetitive and controlled synthetic growth with branching was
fi rst introduced by Fritz Vögtle in 1978 to achieve the construction of rather
low - molecular - weight ' cascade ' polyamines. The introductory sentence of this
article ['For the construction of large molecular cavities and pseudocavities that
are capable of binding ionic guests and molecules (as complex or inclusion
compounds) in a host-guest interaction, synthetic pathways allowing a fre-
quent repetition of similar steps would be advantageous.'] opened the fi eld of
cascade and dendritic chemistry as an entirely novel fi eld. [E. Buhleier
et al.
' Cascade ' - and ' nonskid - chain - like ' syntheses of molecular cavity topologies.
Synthesis
1978; 155-158]. However, it was not until 1985 that George Newkome
and Donald A. Tomalia independently published two new iterative synthetic
protocols for the preparation of large tree-like macromolecules named ' arborols '
and 'dendrimers', respectively. Concerning glycodendrimers, they fi rst appeared
in 1993 [R. Roy
et al.
Solid phase synthesis of dendritic sialoside inhibitors
of infl uenza A virus haemagglutinin.
J Chem Soc Chem Commun
1993;
1869 - 1872].
ferences exist in terms of rigidity and compaction, dendrimers are often compared
to ' artifi cial proteins' with their globular structures, mostly with a high density of
peripheral functionalities and a small molecular ' volume ' [12, 13] .
Tomalia
et al.
fi rst introduced the term 'dendrimer' that arises from the Greek
'
dendron
' = ' tree ' or ' branch ' and '
meros
' = ' part ' , developing at the same time effi -
cient original methodology that still constitutes the preferred commercial route to
the trademarked Starburst dendrimer family with molecular weights ranging from
several hundred to over 1 million Daltons (that is generations 1- 13) [13] .
Until the mid 1990s, the synthetic challenge of such aesthetic structures stimu-
lated numerous research groups that had intensively investigated several synthetic
approaches. Those efforts gave rise to original dendritic architectures emerging
from two main chemical strategies that were used to construct perfectly branched
dendrimers - the divergent and the convergent approaches. Over time, an acceler-
ated version of the convergent strategy has been developed in order to increase its
throughput and effi cacy by using clever adaptations of cores or dendrons. Undoubt-
edly, biology and nano-medicine, more particularly biomedical and therapeutic
applications, represent the domains that have generated the highest interest in
these architectures.
The use of dendrimers in biological systems and systematic studies of the most
common dendritic scaffolds to determine their biocompatibility, such as
in vitro
and
in vivo
cytotoxicity, their biostability or immunogenicity have been reviewed
extensively [14]. One typical example concerns the use of dendrimers as 'glycocar-
riers' for the control of multimeric presentation of biologically relevant carbohy-
drate moieties that are useful for targeting modifi ed tissue in malignant diseases
