Andrew J. Sawyer

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Despite advances in diagnostic imaging and drug discovery, primary malignant brain tumors remain fatal. Median survival for patients with the most severe forms is rarely past eight months. The severity of the disease and the lack of substantial improvement in patient survival demand that new approaches be explored in drug delivery to brain tumors. Recently,(More)
We developed a multi-functional construct capable of controlled delivery of bioactive substances that can improve wound repair by supporting the intrinsic ability of the skin to heal. We synthesized electrospun scaffolds-composed of a blend of the degradable polymers poly(l-lactide) (PLA) or polycaprolactone (PCL)-that produce highly efficient non-viral in(More)
This study investigates methods of manipulating the brain extracellular matrix (ECM) to enhance the penetration of nanoparticle drug carriers in convection-enhanced delivery (CED). A probe was fabricated with two independent microfluidic channels to infuse, either simultaneously or sequentially, nanoparticles and ECM-modifying agents. Infusions were(More)
Direct delivery of chemotherapy agents to the brain via degradable polymer delivery systems—such as Gliadel®—is a clinically proven method for treatment of glioblastoma multiforme, but there are important limitations with the current technology—including the requirement for surgery, profound local tissue toxicity, and limitations in diffusional penetration(More)
Glioblastoma multiforme (GBM) is a fatal brain tumor characterized by infiltration beyond the margins of the main tumor mass and local recurrence after surgery. The blood-brain barrier (BBB) poses the most significant hurdle to brain tumor treatment. Convection-enhanced delivery (CED) allows for local administration of agents, overcoming the restrictions of(More)
Nanopatterning of biomaterials is rapidly emerging as a tool to engineer cell function. Bulk metallic glasses (BMGs), a class of biocompatible materials, are uniquely suited to study nanopattern-cell interactions as they allow for versatile fabrication of nanopatterns through thermoplastic forming. Work presented here employs nanopatterned BMG substrates to(More)
Thrombospondin (TSP)-2-null mice have an altered brain foreign body response (FBR) characterized by increases in inflammation, extracellular matrix deposition, and leakage of the blood-brain barrier (BBB). In the present study, we investigated the role of TSP-2 in BBB repair during the brain FBR to mixed cellulose ester filters implanted in the cortex of(More)
OBJECTIVE The brain foreign body response (FBR) is an important process that limits the functionality of electrodes that comprise the brain-machine interface. Associated events in this process include leakage of the blood-brain barrier (BBB), reactive astrogliosis, recruitment and activation of microglia, and neuronal degeneration. Proper BBB function is(More)
Management of skin wound infections presents a serious problem in the clinic, in the community, and in both civilian and military clinical treatment centers. Staphylococcus aureus is one of the most common microbial pathogens in cutaneous wounds. Peptide-morpholino oligomer (PMO) conjugates targeted to S. aureus gyrase A mRNA have shown the ability to(More)
Implantation of biomaterials elicits a foreign body response characterized by fusion of macrophages to form foreign body giant cells and fibrotic encapsulation. Studies of the macrophage polarization involved in this response have suggested that alternative (M2) activation is associated with more favorable outcomes. Here we investigated this process in vivo(More)