Publication Date


Document Type


Committee Members

Eric Fossum (Advisor), Pavel Ioana (Committee Member), Kenneth Turnbull (Committee Member)

Degree Name

Master of Science (MS)


Modified HPEI was used to determine if the LCST could be controlled by varying multiple variables, including: percent modification, pH, salt solution concentration, and weight percent. Two modifications were done with butylene oxide (Butox) and isobutyryl amide (IBAm). Specifically, 100% (HPEI-Butox1.00)butoxylated and 10% (HPEI-IBAm0.10), 54% (HPEI-IBAm0.54), and 70% (HPEI-IBAm0.70) amidated samples were synthesized. Additionally, HPEI-IBAm0.54 was further modified with hydroxyl ethyl groups (HPEI-IBAm0.54 Eox0.46) and ethyl groups (HPEI-IBAm0.54-Et0.44). The LCSTs of all amidated systems were below body temperature, 37 °C, at pH = 7.4. This indicates an ability of these systems to be used as a vector for gene delivery. A PBS salt solution lowered the LCST, while weight percent had a non linear effect on the LCST. Transfection data on the 54% amidated HPEI system showed transfection efficiency equivalent to control transfectant, LT1. These data suggest a strong potential for using modified HPEI systems as nonviral gene vectors.

Page Count


Department or Program

Department of Chemistry

Year Degree Awarded


Included in

Chemistry Commons