Controlled Release Films and Functional Surfaces Targeting Infection, Inflammation, and Bleeding

Anita Shukla, Rice University

Current techniques used to treat various aspects of traumatic injury including bleeding, infection, and inflammation, often lack efficacy due to difficulty of application, inadequate drug loading, and lack of control over therapeutic release.  Traditional pressure based methods used to control bleeding are not suitable for incompressible or complex wounds.  There is increasing interest in non-pressure based hemostatic dressings; however, many of the existing dressings are not amenable for use in complex sites and are often accompanied by adverse side effects.  Additionally, patients are typically administered broad-spectrum antibiotics to prevent and eliminate infection following injury.  The systemic overuse of antibiotics has led to a worldwide increase in drug-resistant bacteria.  As an alternative to these conventional treatments, local therapeutic delivery has the potential to effectively treat cellular dysfunction while avoiding drug toxicity.  In this seminar, Dr. Shukla will discuss her research on the development of multilayer films that act as local drug delivery coatings and effectively target infection, inflammation, and bleeding.  The versatile layer-by-layer (LbL) assembly technique was used to engineer these coatings to exhibit a range of favorable drug release profiles and large loadings of a broad range of therapeutics.  The drugs that were incorporated include potent antibiotics, such as vancomycin, and exploratory drugs, such as antimicrobial peptides, along with non-steroidal anti-inflammatory drugs and hemostatic agents such as thrombin. Electrostatic and hydrogen bonding interactions were used to assemble these multilayer films.  The drug loading and release properties of these films were found to be strong functions of the film architecture and LbL assembly technique utilized (spray or dip LbL), both of which influence the formation of favorable interactions between film components.  These films were successfully applied to a range of common medical devices including bandages, sutures, and intraocular lenses.  All film released therapeutics retained complete efficacy in vitro.  The hemostatic films developed in this work were also tested in vivo in a porcine spleen bleeding model and found to promote hemostasis in less than one minute following application.