Biomedical Engineering Reference
In-Depth Information
Chapter 1
Antibody-Functionalized Inorganic NPs:
Mimicking Nature for Targeted Diagnosis
and Therapy
Alessandra Quarta, Liberato Manna, and Teresa Pellegrino
1.1
Introduction
Starting from raw materials, nature has developed macro- and nanoscale systems in
which multiple processes, controllable at molecular level, are integrated into highly
sophisticated and functional solutions. Understanding how these subunits assemble
at different levels of complexity, and how this translates in the ability to perform
specific functions, has inspired the development of artificial nanomaterials which
mimic the naturally occurring processes. This is of particular relevance when such
artificial nano-objects are engineered to be biologically active and thus mimicking
some protein functions.
Antibodies are proteins that are naturally produced by the immune system of a
guest organism, as a consequence of the biological response to identify and
recognize extracellular ligands, called antigens, present on the surface of invader
organisms or cells (such as viruses, bacteria, tumor cells), and subsequently to
promote the immune response of the guest organism as a defense mechanism.
Thanks to the unique affinity between the antibody and the antigen, which is
often compared to that of a lock/key couple, the interaction of antibodies toward
their corresponding targets is highly specific even at very low concentration of
antigen expression. Once the antibody-antigen pair is activated, this stimulates the
immune response, as demonstrated for antibodies that are specific toward the cell
targets overexpressed in many different diseases.
As an effort toward mimicking these natural defense mechanisms and thanks to
the research and development of monoclonal antibodies, in the last 30 years, many
antibody-based formulations have been approved as immunotherapeutic agents to
