BIOE 442, Tissue Engineering Module
Research Paper Assignment

Research Paper on PLLA and PLGA as Tissue-Engineered Materials

Task:
Write a research paper to effectively communicate the methods and results of the Tissue Engineering Module. The experiments in the Tissue Engineering Module comprise many of the basic types of experiments that would be required to do a preliminary investigation of a tissue-engineered product. The four major avenues of research that were pursued include the following:

• PLLA Synthesis
• Chemical Characterization of PLLA and PLGA
• PLLA and PLGA Degradation
• HDF Cell Viability, Attachment, and Proliferation on PLLA Films

Individual Assignment:
In the Tissue Engineering Module, a team of two students collects data and results. However, each student must do his/her own data calculations. Also, each student must write her/his own research paper. Students are encouraged to talk to each other, the teaching assistants, and the instructor about the calculations and the research paper.

Research Paper Specifics:
The research paper should be 15-20 pages plus appropriate figures and tables. The general structure and style of the paper is the same as that used in BIOS 311. See the website for details: http://www.owlnet.rice.edu/~bios311/bios311/sciarticle.html . Also, there is a paperback book, "Writing Technical Papers in the Biological Sciences", 3 rd Edition, V.E. McMillan, that is available in the teaching lab for reference. Several research papers are included after the Tissue Engineering Module protocols in the course pack. These papers are good examples and also contain some helpful information and data for comparison.

Issue for Introduction
1. Appropriate background material.
2. Motivation for research work.
3. Clinical uses of PLLA and PLGA.

Hints on Materials and Methods Section:
This section should succinctly summarize the methods used to conduct the experiments. The protocols you are using are operational protocols and are much more detailed than what is appropriate for a research journal. For example, the protocols on p. 28 steps 1.-8. can be summarized as followed: "10.0 g of L-Lactide was combined with 0.475 g of an 8% solution of stannous octoate in hexane in a 100 mL round bottom flask. The solution was heated for 40 min at which time the mixture melted into a liquid." Also, do not say, "I followed the protocol on page 34."

Details on the equipment (e.g. DSC, FTIR, GPC, Coulter Counter) should be limited to make and model and specific operating parameters (e.g., ramp time for the DSC, flow rate for the GPC, upper and lower limits on the Coulter Counter, etc.).

Since you developed the protocols for the HDF cell assays, these need to be described in reasonable detail. However, you should provide general methods, not operational methods. For example, suppose you are washing cells with 3 mL sterile PBS. It is appropriate to write, "the cells were rinsed three times with 3 mL sterile PBS." It is not appropriate to write, "3 mL of sterile PBS was aliquoted using a 5 mL sterile pipette to the 12 well plate. Then, a glass aspirating pipette that was attached to a vacuum line that was attached to a pump was used to remove the PBS from the plate. Then, an additional 3 mL sterile PBS was aliquoted using a 5 mL sterile pipette."

For all the experiments, report any difficulties encountered (e.g. did not recover any polymer during Polymer Clean-up, could not recover cells from films using trypsin).

Technical Content for Results and Discussion:
Your research paper should include the following:
1. Molecular weights of PLLA, PLGA based on GPC analysis.
2. Results from FTIR scans of PLLA and PLGA. Identify the different functional chemical groups on the scans.
3. Results from DSC scans of PLLA and PLGA. Compare to literature values.
4. Degradation of PLLA and PLGA. Consider changes in morphology, shape/size, weight, and molecular weight over time.
5. Synthesis of PLLA. Report the yield and/or recovery.
6. Demonstration of HDF cell viability on PLLA films. See "Questions to Consider." (p. 41) for specific questions to address.
7. Demonstration of HDF cell attachment on PLLA films. See "Questions to Consider." (p. 42) for specific questions to address.
8. Demonstration of HDF cell proliferation on PLLA films. See "Questions to Consider." (p. 44) for specific questions to address.
9. Include appropriate statistics to describe your sample sets.
10. Compare and contrast PLLA and PLGA.
11. Use of PLLA and PLGA in tissue engineering applications.

Grading and Due Dates:
The research paper on the Tissue Engineering Module will count for 24% of the total course grade.

The draft paper will count for 33% of the grade for the Tissue Engineering Module. The focus of the evaluation will be on organization, the materials and methods section, and results and discussion sections for completed experiments. WRITE AS MUCH AS YOU CAN. Grades will be based partially on how much you have put together and written. Consider outlining the sections that are not complete so that you (and Dr. Saterbak) can get a sense of the flow of the whole paper. The draft is due on Session 10 of the Tissue Engineering Module (see chart below).

The final research paper will count for 67% of the grade for the Tissue Engineering Module. The final paper will be evaluated based on the description and criteria presented on the BIOS 311 website (listed above). Improvements from the draft paper will be noted and will affect the final grade. The draft paper should be turned back in with the final paper. The final paper is due two weeks after Session 12.