Biomedical Engineering Reference
In-Depth Information
Chapter 3
Biocompatibility and
Functionalization
Chapter Outline
3.1 Introduction
83
3.3.2 Covalent Conjugation of
Biomolecules to NPs
3.2 Nanomaterial conversion
into the water-soluble form
98
84
3.3.3 Physical Adsorption
102
3.2.1 Ligand Exchange
85
3.3.4 Electrostatic Charge-
charge Interaction
3.2.2 Thiols for Ligand
Exchange
106
87
3.4 Applications of biocompatible
NMs
3.2.3 Encapsulation of NMs
89
106
3.2.4 Polymer Coating
91
3.5 Conclusions
111
3.3 NM Bioconjugation
95
3.3.1 NM Bioconjugation
Techniques
96
3.1 INTRODUCTION
One of the most important challenges in the medical applications of nano-
materials (NMs) is surface modification that allows for biocompatibility and
functionalization. Effective surface modifications as well as highly controlled
surface conjugation strategies are needed to incorporate specific biomolecules
on the surface or inside the NMs. However, success in functionalization depends
on many factors that include NMs' size, shape, charge, chemistry, and surface
modification. These factors are often difficult to vary independently, so the con-
tribution of each is difficult to generalize.
The small sizes of NMs that approach the atomic level, more often than not,
invalidate the governing rules at the macroscopic level involving these chemi-
cals. At the nanometer scale, quantum mechanical effects begin to emerge lead-
ing to varied and unexpected physicochemical properties.
1-4
Hence, modeling
and indirect methods are frequently employed to accurately investigate the intri-
cate interactions and properties of materials at the nanoscale. It is important to
note that these novel and unique properties enable nanotechnology, specifically
for nanomedicine, to provide powerful solutions to various problems. With the
introduction of the scanning tunneling microscopy (STM) in the early 1980s, the
