Folate-targeted verrucarin A reduces the number of activated macrophages in a mouse model of acute peritonitis.

Activated macrophages contribute prominently to the progression and maintenance of almost all inflammatory and autoimmune diseases. Although non-specific elimination of these phagocytes has been shown to treat animal models of inflammatory disease, the same therapies have been compromised by unacceptable toxicities, because they also kill quiescent macrophages in healthy tissues. In the studies below, we exploit upregulation of folate receptor beta (FRβ) on inflammatory (but not resting) macrophages to target a cytotoxic drug selectively to the inflammatory subset of macrophages.

Use of Thromboelastography (TEG) for Detection of New Oral Anticoagulants.

Context: The clinical introduction of new oral anticoagulants (NOACs) has stimulated the development of tests to quantify the effects of these drugs and manage complications associated with their use. Until recently, the only treatment choices for the prevention of venous thromboembolism in orthopedic surgical patients, as well as for stroke and systemic embolism in patients with atrial fibrillation, were vitamin K antagonists, antiplatelet drugs, and unfractionated and low-molecular-weight heparins. With the approval of NOACs, treatment options and consequent diagnostic challenges have expanded.

Synthesis and activity of folate conjugated didemnin B for potential treatment of inflammatory diseases.

A folate receptor targeted didemnin B conjugate was synthesized using a hydrophilic peptide spacer linked to folate via a releasable disulfide carbonate linker. Cell cytotoxicity and TNF-α inhibition in RAW264.7 macrophage-like cells exhibited IC(50)s of 13 and 5 nM, respectively.

Selective capture and identification of pathogenic bacteria using an immobilized siderophore.

Rapid identification of infectious pathogens constitutes an important step toward limiting the spread of contagious diseases. Whereas antibody-based detection strategies are often selected because of their speed, mutation of the pathogen can render such tests obsolete. In an effort to develop a rapid yet mutation-proof method for pathogen identification, we have explored the use of "immutable ligands" to capture the desired microbe on a detection device.

Two-photon Luminescence Imaging of Bacillus Spores Using Peptide-functionalized Gold Nanorods.

Bacillus subtilis spores (a simulant of Bacillus anthracis) have been imaged by two-photon luminescence (TPL) microscopy, using gold nanorods (GNRs) functionalized with a cysteine-terminated homing peptide. Control experiments using a peptide with a scrambled amino acid sequence confirmed that the GNR targeting was highly selective for the spore surfaces. The high sensitivity of TPL combined with the high affinity of the peptide labels enables spores to be detected with high fidelity using GNRs at femtomolar concentrations.

Immunomagnetic diffractometry for detection of diagnostic serum markers.

We describe an integrated approach for detection of diagnostic markers using in situ assembled optical diffraction gratings in combination with immunomagnetic capture. Folate receptor (FR), a serum protein indicative of various cancers, was chosen as a model system to demonstrate the potential of the method. Magnetic beads coupled to FR antibody were used to capture FR from serum.

Discovery and development of folic-acid-based receptor targeting for imaging and therapy of cancer and inflammatory diseases.

In order to avoid the toxicities associated with prescription drug use today, we have explored novel methods for delivering drugs selectively to pathologic cells, thereby avoiding the collateral damage that accompanies their uptake by healthy cells. In this Account, we describe our quest for the ideal targeted therapeutic agent. This effort began with a search for ligands that would bind selectively to pathologic cells, displaying no affinity for healthy cells.

Synthesis and activity of a folate peptide camptothecin prodrug.

A folate receptor targeted camptothecin prodrug was synthesized using a hydrophilic peptide spacer linked to folate via a releasable disulfide carbonate linker. The conjugate was found to possess high affinity for folate receptor-expressing cells and inhibited cell proliferation in human KB cells with an IC(50) of 10nM. Activity of the prodrug was completely blocked by excess folic acid, demonstrating receptor-mediated uptake.

Detection of folate binding protein with enhanced sensitivity using a functionalized quartz crystal microbalance sensor.

In this report, we describe the development of a quartz crystal microbalance biosensor for detection of folate binding protein (FBP). Using a simple folate-BSA conjugate adsorbed onto a Au-coated quartz sensor, a detection limit of 30 nM was achieved. Binding of FBP to the sensor surface could be blocked at concentrations as high as 1 microM with a 100-fold excess of folic acid, indicating the specificity of the folate-FBP interaction and the absence of nonspecific binding to the functionalized surface.

Detection of Bacillus subtilis spores using peptide-functionalized cantilever arrays.

We move beyond antibody-antigen binding systems and demonstrate that short peptide ligands can be used to efficiently capture Bacillus subtilis (a simulant of Bacillus anthracis) spores in liquids. On an eight-cantilever array chip, four cantilevers were coated with binding peptide (NHFLPKV-GGGC) and the other four were coated with control peptide (LFNKHVP-GGGC) for reagentless detection of whole B. subtilis spores in liquids.