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

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 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...

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....

Group 076-11: Modulating Hydrogel Structure for Therapeutic Release

Search This Blog