Nanostructured Porous Biomaterials for Controlled Drug Release Systems - Biomaterials Fabrication and Processing - page 193

8 Nanostructured Porous

Biomaterials for Controlled
Drug Release Systems

Yang Yang Li, Jifan Li, and Bunichiro Nakajima

CONTENTS

8.1 Introduction........................................................................................................................... 193
8.2 Nanostructured Porous Materials ......................................................................................... 196
8.2.1 Soft Nanostructured Porous Materials ...................................................................... 196
8.2.2 Inorganic Nanostructured Porous Materials ............................................................. 197
8.2.2.1 Mobil Composition of Matter-41 Porous Silica .......................................... 200
8.2.2.2 Biomimetic Siliceous Nanocapsules ........................................................... 206
8.2.2.3 Porous Silicon ............................................................................................. 206
8.3 Summary and Outlook ......................................................................................................... 209
Acknowledgments .......................................................................................................................... 210
References ...................................................................................................................................... 210

8.1 INTRODUCTION
The advancement in science and technology, especially since 1970, has propelled extensive research
in the biomedical fi eld. This research is aimed at discovering effective medicines to prevent disease,
promote health, and relieve pain and suffering. After an appropriate drug is identifi ed, determin-
ing the method to deliver and release it into the body is as crucial as the therapeutic activity of the
drug itself. Controlling the delivery of the drug is a challenging yet essential task in many situations
such as the slow release of water-soluble agents, fast release of poor water-soluble agents, localized
drug delivery, targeted drug delivery directed at the specifi c cell tissue or site, coordinated delivery
of multiple drugs, and systems based on carriers with a short life time. A drug delivery method
that involves a controllable transport path and release rate and is self-regulated and self-reporting
is often desirable. 1 This chapter introduces the common biomaterials for controlled drug delivery
and then focuses on nanostructured porous materials such as silicon-based photonic and templated
materials as examples.
It has been shown that the healing effectiveness of the medicine can often be improved by an
optimal drug delivery system. For example, previously, diabetic patients were injected with multiple
doses of insulin daily and the effects of this approach were diffi cult to control. Today, because of the
advancement in drug delivery technologies, various formulations are available for insulin treatment.
These formulations offer rapid or delayed action over short or long durations, respectively, to meet
the needs of different patients to maintain insulin levels within a desired range and to reduce the
long-term consequences of diabetes. However, injection remains the main method of delivery, while
some alternatives such as the programmable implantable insulin pumps and insulin nasal sprays
and mouthwashes are under development to obtain increased patient compliance. 2,3

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