Morgan Gulley Chem430 F16

Chemistry/Biochemistry Research 430

Fall 2016

Morgan Gulley

Senior Chemistry Major with Math & Physics Minors

Research Times

Tuesdays from 1-5 pm in the Trough Lab

section 01 = 0.25 credit = 4 hours per week.

General Information

Advisor: Audra Sostarecz

Other research student collaborators: Khader

Other Research Collaborators: NONE

Proposed Research Project

Langmuir Monolayer and AFM Analysis of a Collagen/Phospholipid/Titanium Model Membrane System for the Investigation of Osteoblast Affinity to Titanium Rods

Langmuir-Blodgett Monolayers of collagen and phospholipids will be used as a model system for the affinity of osteoblasts to titanium rods. The Langmuir Monolayer technique allows for the analysis of the organization of amphiphilic molecules at an air-water interface and is, therefore, a useful technique for the formation of model cell membranes. Collagen, Type I from calf skin, will be used as a substitute for human bone and titanium nitride foil will be used as the substrate due to its increased biocompatibility. Langmuir monolayers of collagen are found to have a higher degree of order (less fluidity) and to be more stable indicated by a higher surface pressure at low molecular areas when incorporated into a film with phospholipids such as dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine (DPPE). Similarly, transfer ratio data of collagen monolayers to silicon (SiO2) substrates increased in the presence of DPPC and DPPE indicating that this may be a good model system for this investigation. These studies were completed last semester. In preparation for current experiments involving Atomic Force Microscopy analysis of collagen/phospholipid monolayers transferred to titanium nitride foil using dipalmitolyphosphatidylglycerol (DPPG) as the lipid because of its impact on bacterial resistance in the bone cell model membrane, we have determined that we can use the ezAFM for analysis of transferred multilayers of arachidic acid. It was also determined last semester that a liquid expands/liquid condensed phase of DPPC transferred onto SiO2 by AFM analysis. With this information present, the transfer of a collagen/phospholipid monolayer should be possible, and will be tested.

Instruments to be used

Langmuir-Blodgett Monolayer Trough

ezAFM

References

Mehdi Kazemzadeh-Narbat, Benjamine F.L. Lai, Chuanfan Ding, Jayachandran N. Kizhakkedathu, Robert E.W. Hancock, and Rizhi Wang. “Multilayered Coating on Titanium for Controlled Release of Antimicrobial Peptides for the Prevention of Implant-Associated Infections.” Biomaterials 34 (2013): 5969–77.

Jeanette Libera, Thomas Pomorski, Oliviera Josimovic-Alasevic, Karl-Gerd Fritsch, and Andreas Herrmann. “Internalization of Phospholipids from the Plasma Membrane of Human Osteoblast Depends on the Lipid Head Group.” Journal of Bone and Mineral Research 14, no. 5 (1999): 690–99.

Research pledge

I, Morgan Gulley, have read the Chem/Bioc 430 course syllabus and understand the general structure and expectations of the research program. The above material was prepared after consultation, and in conjunction with my research advisor, Audra Sostarecz.