A biomaterial is any synthetic material that when placed in the body elicits minimal adverse response and typically replaces natural body parts. -- Today, biomaterials are used in all parts of our bodies: teeth, eyes, joints, heart or skin. Biomaterial products include heart valves, coronary stents, contact lenses, artificial joints and skin. These biomaterials can be constructed from metals, alloys, polymers, biopolymers or any combination of these materials. Biomaterials can be engineered to deliver drugs, proteins, DNA or living cells to a specific target. They can be engineered to change as a result of their environment or biodegrade into natural components. -- Biodegradable polymers are being used in a variety of research efforts. These materials can decompose and disappear from the body and are desirable for short-term applications mentioned biodegradable polymers kit above. For example, bio-active molecules can be blended with biodegradable polymer to construct drug delivery systems for the body. -- One of the most studied biodegradable systems is Poly(lactide-co-glycolides) (PLGA). Polylactides and polyglycolides were used originally as absorbable suture materials. The major advantage of these degradable polymers is that they decompose, in the presence of water, into biologically acceptable molecules that are metabolized and removed from the body via normal metabolic pathways. PLGA polymers will eventually break down to lactic acid and glycolic acid, enter the Kreb's cycle, and be further broken down into carbon dioxide and water and excreted through normal processes. -- In this experiment students will manufacture their own delivery system by blending PLGA with CaCl2. They will monitor the release of calcium over several weeks. The calcium concentration will be determined by a simple titration procedure. The results will be plotted for calcium concentration as a function of time.