מעוז שמש

תלמיד המחלקה לתואר שני ירצה בנושא:

Novel Hybrid Wound Dressings with Controlled Release of Pain Killers

Wound dressings based on naturally derived materials are becoming widely used in the biomedical field for their similarity to the extracellular matrix and inherent cellular interaction. A wound dressing should ideally provide an optimal healing environment in which healing can occur at a maximum rate. After burn injury, pain management is challenging from initial emergency room care to the rehabilitation phase of burn care. A novel biodegradable bilayer composite wound dressing which releases analgesic drugs in a controlled manner to the surrounding tissue is proposed as means to improve therapeutic effectiveness and patient comfort in burn injury patients. The composite dressing was designed according to the bilayer structure concept, i.e. the upper "dense" layer is based on a porous Poly-(DL-lactic-xo-glycolic acid) (PDLGA) designed to control moisture transmission, prevent bacterial penetration and acts as a drug reservoir.  The lower spongy collagen layer designed to absorb wound exudates, smoothly adhere to the wet wound bed as well as to accommodate newly formed tissue. The unique design system enables the combination of good mechanical and physical properties along with adjustable desired drug release profile.

In-vitro drug release profile of the analgesic drug ibuprofen and the anesthetic drug bupivacaine was determined by the use of high performance liquid chromatography (HPLC). The dominant mechanism controlling the release kinetics of ibuprofen is diffusion with an initial burst release and after a decreasing release rate. Bupivacaine demonstrated a more complex pattern of release consisting of 3 phases of release. The water absorption capacity and vapor permeability (WVTR) were found to be beneficial for the application. A large range of WVTR's between 1950 to 3088 g/m²/day was measured through changes of the porous matrix for both drugs, demonstrating the versatility of the freeze-drying of inverted emulsions technique. In addition, maximal water absorption of ~200 mg/cm² was displayed, demonstrating the ability of the spongy layer to absorb rapidly large quantities of wound exudates and maintain high water absorption capacity for almost a month. Environmental Scanning Electron Microscopy observations of our new structure discovered a unique hybrid structure in which the natural polymer (collagen) and the synthetic polymer (PDLGA) are hold together by a third interfacial layer.

העבודה נעשתה בהנחייתה של פרופ' מיטל זילברמן, המחלקה להנדסה ביו-רפואית,

אוניברסיטת תל-אביב

ההרצאה תתקיים ביום ראשון 3.6.2012, בשעה 14:45,

בחדר 315, הבניין הרב תחומי, אוניברסיטת תל אביב