Project Overview

This project is being done as part of Drexel University's freshman engineering design curriculum. The task is to create a hydrogel using sodium alginate that is structured in such a way as to control the release of therapeutics over time.

Goals

The goal of this project is to control the release rate of a therapeutic through the manipulation of the structure of alginate hydrogel. Our group decided to create a prototype of a wound dressing, which will be used specifically to treat first- and second-degree burns. This will require a process including many phases, with examples including research, design, construction, testing, etc.

Requirements

The major requirement of this project is the use of alginate hyrdogel, as the manipulation of this material to serve a purpose is the central goal of this project. Additionally, the prototype is required to be effective in controlling the rate of release of a theraputic agent. The controlled release is expected to allow the maintenance of a safe and effective concentration of the therapeutic agent in the patient's system over an extended period of time. This concentration is to be determined using the drug's therapeutic index.

Comments

Week Five Progress

During week five, more research was done and the group was able to decide on the exact concentrations of calcium chloride to use in making each hydrogel layer as well as in the beads. The higher the concentration of calcium chloride, the more dense the hydrogel layer will be. Thus, for the thin, low-density layer, as well as for the low-density beads, a 5% calcium chloride solution will be used. For the thick, high-density layer, a 7% calcium chloride solution will be used. Refer to Figure 1, below, for a visual of the design. Figure 1: Preliminary Diagram of the Hydrogel Wound Dressing Another task that was completed this week was additional planning for the testing phase. Once the hydrogel has been constructed, samples of it will be placed into cuvettes, and fluorescently-labeled bovine serum albumin (FITC-BSA) will be injected into the cuvettes, one at a time, in intervals of four hours. This will occur over a period of two days, and at the end of the two day...

Week Four Progress

Our focus this week was finding the correct placebo for our design. Prior to this week, we had expected to use zinc oxide in our module but we realized it did not have a high enough molecular weight. Therefore, the zinc oxide would disperse from the hydrogel beads too rapidly. After some research and guidance from our professor, we decided to use Fluorescein Isothiocyanate-Bovine Serum Album (FITC-BSA), which is a hydrophilic protein with a molecular weight of 66 kg/mol [1]. FITC-BSA will also be our signal source for measuring the rate of dispersion from the beads. As seen in Figure 1, FITC-BSA is vivid in color and allows the protein's diffusion throughout the hydrogel to be observed easily. We've decided to initially use 0.25 mg/ml as the concentration of FITC-BSA within our design. Figure 1: FITC-BSA (green) seen in samples of HeLa cells [2] References: [1] Bovine Serum Albumin Conjugates Product Information , 1st ed. Molecular Probes, 2005. [2] S. Sarker, R....

Week Seven Progress

This week, the group's main focus was to create samples of hydrogel for testing. As we set out to test absorbance values, we developed a procedure that would allow us to create several samples of gel over a long period of time. Table 1, below, was used to organize and label the samples during their preparation. Table 1: Labeling Method Used for Preparing Samples Table 2: Volumes Required for Mixture in Step 1 Procedure 1: Mixing the Alginate Solution 1. In a 150-mL beaker, mix the volumes of water and sodium alginate required for the solution you are making, found in Table 2. (This step must be done for each of the 3 sodium alginate solutions. Then, the volumes for the 7% and the 2% solutions must be halved and mixed separately, only to be combined into a test tube at the end of this procedure). 2. Add .01 mL of FITC-BSA to the sodium alginate solution created in step 1. Mixing the Calcium Chloride 3. Mix 25 mL of water and 5 mL of 30% calcium chloride i...

Group 076-11: Modulating Hydrogel Structure for Therapeutic Release

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