Controlling the assembly of proteins and cells on SiO₂ surfaces

A variety of devices -- biochips, implants, and membrane filters among them -- are challenged in their operation by having to contact biological solutions. An ever-present problem for such devices is "biofouling," resulting from the nonspecific adsorption of proteins, cells, and other agents onto their surfaces. The ability to produce surfaces with specifically immobilized biological species that can avoid the nonspecific adsorption of other species has been essential for constructing solid-state devices that interface to biological systems. An effective strategy for achieving "bioinertness" for surfaces is their modification by poly(ethylene glycol)s (PEGs), which provides protein and cell repelling properties. This thesis centers on the development of ultrathin films of PEG on SiO₂ surfaces that 1) can resist the nonspecific adsorption of proteins and cells ("bioinert surfaces ") and 2) can provide surface sites for the specific immobilization of biomolecules ("bioactive surfaces "). Effective methods to achieve these goals were accomplished by incorporating multivalent surface anchoring groups into one polymer chain or by forming densely-packed monolayers of PEG on surfaces. In one approach, bioinert surfaces were prepared by a multivalent attachment of a PEG-grafted polymer backbone to a surface. Two systems were examined: 1) graft copolymers of poly(acrylic acid) expressing PEG-containing side chains, and 2) a random copolymer composed of an "anchor part" (trimethoxysilane) and a "functional part" (PEG). In the first system, PEG-containing films were formed by an electrostatic interaction between the PAA backbone and the underlying amine-modified surface. In the second system, the formation of

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Seong, Jiehyun, 1973-

Advisor dc:contributor.advisor

• Paul E. Laibinis and Robert Langer.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/30059

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/30059