Multifunctional ORMOSIL and PAA Nanoparticles
Anurag Gupta
1
, K.V. R Rao
1
, Paula Pera
2
, Shouyan Jason Wang
3
, Joseph R. Missert
1
,
Tymish Ohulchanskyy
4
, Indrajit Roy
4
, Janet Morgan
2
, Paras N. Prasad
4
, Raoul Kopelman
3
and Ravindra K. Pandey
1,4,*
1
Photodynamic Therapy Center, Cell Stress Biology,
2
Department of Dermatology, Roswell Park
Cancer Institute, Buffalo, NY, 14263,
3
Department of Chemistry, University of Michigan, Ann
Arbor, MI, 48109-1055,
4
The Institute for Lasers, Photonics and Biophotonics, Department of
Nuclear Medicine, SUNY at Buffalo, Buffalo, NY 14221
ABSTRACT
Various problems arising during molecular imaging of different fluoroprobes and metabolites used in PDT can be
circumvented by focusing on multifunctional therapy agents. Thus an effective photo sensitizer coupled with other
useful roles to play in PDT treatment make nanoparticles as a good vehicle for different delivery assuming
multifunctional roles not only in PDT but also as therapeutic agents for targeted delivery. A new approach is the
involving use of 100 nm NPs as photo sensitizers and/or imaging agents. In our Lab., we employ two such NPs and are
ORMOSIL (organically Modified Silica) and PAA (Polyacrylamide) which are found to be biologically very safe
without disturbing the therapeutic value. The size of the nanoparticles determined by TEM and Dynamic Light
Scattering are ~30 nm. These NPs are taken up in conjunction with cyanine dye at near infra red as it has been reported
in literature that encapsulated NPs shows very low singlet oxygen production compared with the post-loaded NPs though
the reasons are not yet clear. Therefore, we investigated the idea of post-loading or adsorbing vis-à-vis encapsulation.
Keywords: Nanoparticles, PDT, Photosensitizer, Optical imaging, Photo-bleaching, ORMOSIL, PAA
1. INTRODUCTION
1.1 Nanomaterials
Many areas of science, engineering, medicine are facing continual evolution in needs related to inter-
disciplinary approach. Nanomaterials bring cross-disciplinary perspectives to bear on these areas, in which scientists can
work for convergence for empowerment of humankind. The Zeitgeist of this article is to include representatives of
other disciplines among its supporters, and aims at dissemination towards, and collaboration with, newly developing
areas. The scientific and public resonance of the nanomaterials application domain is far-reaching. The application of
nano-oncology and information understanding technologies to, among many other examples are photo-thermal therapy
and photosensitization. The computer science of relevance to nanomaterials includes high performance computing (e.g.
for theoretical modelling), distributed computing, and dealing with massive databases - very often image databases. The
interface areas with telecommunications and software engineering are now so close that they cannot be separated.
Information retrieval and cognitive science are strongly represented. There is a continuing perception, however, of a gap
between the laboratory research and eventual real application.
Those who are pioneering new approaches in distributed computing, modelling, multiresolution vision
modelling, new information delivery technologies, and who are active in other fields of computer science, statistics and
other disciplines, are very rarely doing such work with nanomaterials in mind. Both nano and other inter-disciplinary
sciences have much to gain from collaborative linkages giving impetus to translational research. In medical
applications, it is important to understand how modern biomaterials can simulate the body’s natural ability to heal and
also a fast growing area of materials that mimics biological function e.g. natural enzymes.
The trend in Condensed Matter Physics towards probing matter on shorter and shorter scales has naturally
focused our attention to the microscopic aspects relevant at the nanometer scale. Scanning probes have led this
revolution, by extending classical characterization techniques (such as indentation testing) to the nanometer scale,
Photodynamic Therapy: Back to the Future, edited by David H. Kessel, Proc. of SPIE Vol. 7380,
73805H · © 2009 SPIE · CCC code: 1605-7422/09/$18 · doi: 10.1117/12.822939
Proc. of SPIE Vol. 7380 73805H-1