Design and Development of Theranostic Nanomedicines - Nanotechnology for Biomedical Imaging and Diagnostics - page 421

etc. Yet unique challenges exist simply due to their nanostructure nature that must
be considered. Finally, if theranostics are to become true personalized medicines,
should we contemplate manufacturing a tailored theranostic nanomedicine for each
individual patient? Could we in the future become able to customize theranostic
nanosystems at the bedside? and if this is the case, how would we assess the safety
and efficacy of these systems? it is now easy to imagine the need for comprehensive
assessment of this emerging field. We also argue that rational design will be critical
to their future clinical utilization. our hope is that theranostics manage to overcome
these obstacles and live to become new medicines rather than interesting engineering
exercise very successful in treating and imaging disease processes in animal models.
however, we would also argue that nanotheranostics hold a great potential to help us
elucidate in vivo disease mechanisms and this potential should be further explored.
The aim of this chapter is to survey some of the most prominent examples of ther-
anostic nanomedicine design and offer arguments for future development of these
agents. We aim to approach theranostics from a new medicine development point of
view where we consider future pharmaceutical production considerations and offer
ideas on how theranostics could be designed to meet these challenges.
it is important to note that theranostic nanomedicine belongs to incredibly active
research discipline of nanomedicine, which itself is in early stages. recent reviews
attempted to both define nanomedicine and provide insights on how far this field has
gone and how close it came to marketed products [1, 2]. authors found that most
of the nanomedicine formulations were designed for iv injection as the route of
administration and more than 80% of nanosystems were delivered through passive
targeting. These trends of course are repeating in the theranostic nanomedicine
research, and we have to ask ourselves if we are maximizing their potential or simply
doing what works and not fully exploring the vast design space of theranostics.
looking at the literature over the past 20 years, it is common to see progression from
imaging nanoreagents and drug delivery nanoreagents to combined formulations,
which we all now name theranostics. however, we should also ask, does a nanopar-
ticle delivery system decorated with an imaging moiety necessarily qualify as a
theranostic? Theranostic nanomedicine division of the national institutes of health
defines theranostic nanomedicine as follows: “Theranostic nanomedicine is the
medical application of nanobiotechnology and refers to highly specific medical
intervention at the nanoscale for diagnosing, curing or preventing diseases.” This
definition is broader than most currently published formulations, which typically
are nanosystems carrying drugs or drug delivery nanosystems with added imaging
entity. Therefore, we propose that designing theranostics should follow more
specific criteria: (i) theranostics should be of small size and narrow size distribution,
preferably monodisperse nanosystems; (ii) all excipients should be biocompatible
and preferably biologically inert; (iii) the imaging capacity of the theranostic
nanosystem should be at its highest level possible, unaffected by the remaining
components of the system and the drug, and comparable to imaging nanoreagent
alone; (iv) the drug loading and adequate drug release profile should be comparable
of the theranostic to other drug delivery nanosystems without the imaging
component; (v) the molecular imaging should provide insight into theranostics