Date of Graduation

Spring 2015

Document Type

Honors Research Project

Degree Name

Bachelor of Science


Chemical Engineering - Cooperative Education

Research Sponsor

Dr. Gang Cheng

First Reader

Dr. Edward Evans

Second Reader

Dr. Jie Zheng


The goal of this project is to improve our understanding of nucleic acid interactions with cationic polymers with the theory that the polymers could protect the nucleic acids from degradation caused by biological enzymes. We seek to understand what the limitations of the cationic polymers are which, in this case, is mainly polymer-DNA compatibility. This experiment utilized peptide-dextran hybrid polymers with differing functionalizations to condense anionic nucleic acids into nanometer-sized polyplexes. Techniques of dynamic light scattering and zeta-potential were utilized to determine the particle sizes and surface charges of polyplexes.

In this experiment, dextran with a molecular weight of 20 kDa was used. The dextran was then functionalized in four combinations: R3H3C or R5H5C conjugations each with and without CB-functionality. Additionally, N/P ratios of 0, 1, 5, 10, 20, and 30 were tested for each combination. The results, quantified in Tables 1 to 4, and summarized in Figure 10 and Figure 11 near the end of this document, indicate dextran polymer compatibility with DNA improves with the addition of CB-functionality, using the larger R5H5C peptide over R3H3C, and increasing N/P ratios.