Week Six Progress

Progress on the hydrogel adhesive prototype has entailed the finalization of the proposed design. As such, it was determined that differentiation of hydrogel density must be attained by varying the concentration of sodium alginate utilized within the individual hydrogel layers. The initial design had called for the variation of calcium chloride concentration, though it was concluded that the variation in calcium chloride density will not contribute appreciably to the densities of the layers. Moreover, the finalized design will exclude hydrogel bead suspensions, as the beads will not contribute to the release of FITC-BSA. Thus, FITC-BSA will become encapsulated within the high-density hydrogel layer, as shown below in Figure 1. To encapsulate the prototype drug, FITC-BSA will be mixed with sodium alginate before calcium chloride solution is added. To quantify the therapeutic release three hydrogel mixtures will be created, including: a high density layer, a low density layer, and a layered hydrogel mixture. The absorbance of light over time will be measured for each mixture by utilizing a spectrophotometer. Subsequently, the results will be graphed to determine the efficacy of the layered hydrogel design. Ideally, the graphed results of the layered hydrogel mixture will yield a quick release of FITC-BSA over time, before delineating a plateau. The results of the spectrophotometry is expected to be favorable given the structural design of the adhesive. Nonetheless, the need for further progress and revision to the design of the hydrogel adhesive will be determined by the results of the spectrophotometry.

Figure 1: Finalized Hydrogel Adhesive Design

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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 One Progress

Figure 1: Diagram of preliminary design The culmination of the hydrogel modulation design will yield a hydrogel wound dressing utilized for the therapeutic treatment of first-degree and second-degree exterior burns. A physical prototype of the hydrogel wound dressing will be produced by precipitating food-grade sodium alginate in a calcium chloride solution. The reaction yields spheres of low-density gel surrounded by a thin gelatinous membrane. The construction of an alginate dressing necessitates ionic cross-linking of the alginate solution with calcium ions, as to form the gel component. Both the high-density and low- density hydrogel layers will be generated in unison, before undergoing the freeze-drying process as to produce porous sheets. The physical prototype will be accompanied by a computer generated model of the hydrogel wound dressing, as evidenced in figure 1. The required components to construct the hydrogel adhesive were determined and subsequently purchased. The r...

Week Three Progress

During Week Three, we discussed and determined our therapeutic agent for the hydrogel module. After extensive research and comparison of our options, we decided the best-suited therapeutic would be zinc oxide. This substance fits our design so well because it is hydrophobic and will slowly disperse through the pores in the bottom hydrogel layer. Zinc oxide has been used in past hydrogel models and has been proven to be effective. It is an agent that has been used in ointments and supplements to treat burns and prevent infections. Likewise, the possibility of overdosing on zinc-oxide necessitates a solution for controlled therapeutic release. The predominant delivery system for zinc oxide is through medicinal cream, the delivery through which enables the therapeutic threshold of zinc oxide to be increased to levels of high toxicity. Symptoms of zinc-oxide overdose include: fever, chills, vomiting, mouth irritation, stomach pain, and yellowing of the eyes and skin. Consequently, the phar...

Group 076-11: Modulating Hydrogel Structure for Therapeutic Release

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