Synthesis and design of polyphosphazene hydrogels for biomedical applications

The work described in this thesis focuses on the development of polymer hydrogels as microscale drug delivery vehicles and for use in biosensors. The first section details the synthesis and characterization of a novel tri-substitued polyphosphazene that contains aryloxy carboxylic acid, glycine ethyl ester, and methoxyethoxyethoxy side groups for potential use in controlled drug release applications. The research has consisted of: (1) Evaluation of the in vitro cytotoxicity of the above mentioned polymer, (2) the formation of hydrogel microspheres from polyphosphazenes that bear carboxylic acid side groups, (3) Examination of polymer microsphere degradation at near physiological conditions, (4) the encapsulation and release of a model protein drug from these microspheres, (5) the immobilization of antibodies to microsphere surfaces, for potential use in targeted drug delivery, (6) the controlled release of multiple drugs from a single microsphere. These topics are detailed in chapters 2--4. The second portion of this work is focused on the synthesis of water soluble polymers that form crosslinked hydrogels by exposure to ultraviolet radiation. The polymers were examined for potential use as hydrogel elements in microscale biosensors. These topics are dicussed in chapters 5 and 6. The specifics of all of the above sections are summarized in the following paragraphs.;In chapter 2, the synthesis of a polyphosphazene that contained sodium oxybenzoate, amino acid ester and alkyl ether side groups is described.;Chapter 3 details a procedure for the covalent attachment of antibodies to the surface of polyphosphazene hydrogel microspheres.;Chapter 4 describes a method for the immobization of drug molecules within polyphosphazene hydrogel microspheres based on two different polymer/drug interactions.;Chapter 5 is a description of the synthesis of polyphosphazenes that bear both methoxyethoxyethoxy and cinnamyl side groups.;Chapter 6 includes an examination of hydrogels based on poly[bis(methoxyethoxyethoxy)phosphazene], (MEEP) for cell encapsulation based applications. (Abstract shortened by UMI.)...