Biodegradable Thermogelling Poly(Organophosphazenes) and Their Potential Biomedical Applications - In-Situ Gelling Polymers: For Biomedical Applications - page 36

Biodegradable Thermogelling
Poly(Organophosphazenes) and Their
Potential Biomedical Applications

Xiao Liu

Abstract Poly(organophosphazenes) as a new type of biodegradable polymers
have been exploited as carriers for various drug delivery systems due to versatil-
ity of molecular structures and easily modulated physico-chemical properties.
Thus, biodegradable thermogelling poly(organophosphazenes) are expected to be
very promising biomaterials as injectable systems with minimal surgical interven-
tion for drug delivery and tissue engineering applications. The key advantage of
thermosensitive hydrogels based on poly(organophosphazenes) over other thermo-
sensitive polymers is the ease of tuning the hydrogel properties by use of differ-
ent compositions of side groups or through variations in co-substituent ratios. A
variety of poly(organophosphazene) thermogels have been developed with desir-
able hydrophobic-hydrophilic balance, controllable degradation rate and suitable
mechanical properties with respect to different applications. This chapter covers a
comprehensive summary of the recent developments in this field of study, includ-
ing polymer design, property assessment and potential biomedical applications.

Keywords Poly(organophosphazene) · Thermogels · Drug delivery · Biodeg radable ·
In vivo

1 Introduction

Hydrogels as a potential controlled drug delivery system and biomedical device
has been extensively studied over the past decade [ 1 ]. One of the more recent
trends is the in situ formation of stimuli-sensitive hydrogels, which can undergo a
simple reversible phase transition (sol-gel transition) with response to the external