Nonhealing chronic wounds are major complications of diabetes resulting in >70,000 annual lower-limb amputations in the United States alone. The reasons the diabetic wound is recalcitrant to healing are not fully understood, and there are limited therapeutic agents that could accelerate or facilitate its repair. We previously identified two active forms of matrix metalloproteinases (MMPs), MMP-8 and MMP-9, in the wounds of db/db mice. We argued that the former might play a role in the body's response to wound healing and that the latter is the pathological consequence of the disease with detrimental effects. Here we demonstrate that the use of compound ND-336, a novel highly selective inhibitor of gelatinases (MMP-2 and MMP-9) and MMP-14, accelerates diabetic wound healing by lowering inflammation and by enhancing angiogenesis and re-epithelialization of the wound, thereby reversing the pathological condition. The detrimental role of MMP-9 in the pathology of diabetic wounds was confirmed further by the study of diabetic MMP-9-knockout mice, which exhibited wounds more prone to healing. Furthermore, topical administration of active recombinant MMP-8 also accelerated diabetic wound healing as a consequence of complete re-epithelialization, diminished inflammation, and enhanced angiogenesis. The combined topical application of ND-336 (a small molecule) and the active recombinant MMP-8 (an enzyme) enhanced healing even more, in a strategy that holds considerable promise in healing of diabetic wounds.

In vivo optical imaging shows that a fluorescent imaging probe, comprised of a near-infrared fluorophore attached to an affinity group containing two zinc(II)-dipicolylamine (Zn-DPA) units, targets prostate and mammary tumors in two different xenograft animal models. The tumor selectivity is absent with control fluorophores whose structures do not have appended Zn-DPA targeting ligands. Ex vivo biodistribution and histological analyses indicate that the probe is targeting the necrotic regions of the tumors, which is consistent with in vitro microscopy showing selective targeting of the anionic membrane surfaces of dead and dying cells.There is a major ongoing research effort to identify oligonucleotide and protein biomarkers of malignant disease. 1 Phospholipid biomarkers are less common, however, there is increasing evidence that the membrane surfaces of certain cells and particles of biomedical significance, smith.115@nd.edu. Supporting Information Available: Experimental details and additional imaging data. The information is available free of charge via the Internet at http://pubs.acs.org. Synthetic zinc(II)-dipicolylamine (Zn-DPA) coordination complexes are known to associate with multianionic phosphorylated biomolecules, 14 and we have discovered that they can be converted into optical imaging probes that target the outer surfaces of anionic vesicle and cell membranes.15 Fluorescent Zn-DPA probes can distinguish dead and dying mammalian cells from healthy cells in a cell culture,16 and also selectively target bacteria in heterogeneous biological media.17 Furthermore, we have recently demonstrated that the near-IR fluorescent probe 1 can be used to image bacterial infections in living mice, 18 indicating that probe 1 has a notable ability to selectively target anionic cells over other anionic sites in the bloodstream and extracellular matrix. Here, we greatly expand the animal imaging capability of probe 1 by showing that it can also target the anionic dead and dying cells within xenograft tumors in rat and mouse models. The structure of probe 1 includes a near-IR carbocyanine fluorophore whose absorption and emission wavelengths of 794 and 810 nm, respectively, are within the optimal window for maximum penetration through skin and tissue. 19 The high tumor selectivity of 1 is demonstrated by comparison to the less-selective imaging that is achieved by using control near-IR fluorophores 2 and 3 whose structures do not have Zn-DPA targeting ligands. The expected ability of probe 1 to selectively target dead and dying cells with exposed anionic phosphatidylserine was confirmed with in vitro fluorescence microscopy studies of mammalian cells treated with a cytotoxic agent. 16 Specifically, treatment of Jurkat cells (T lymphocytes) with camptothecin induced significant amounts of cell death, and as shown in Figure 1, the near-IR probe 1 stained the same cells as fluorescently labeled Annexin V. Using procedures that were approved by the appropriate institutional animal care and use committee, two tumor...

In the face of the clinical challenge posed by resistant bacteria, the present needs for novel classes of antibiotics are genuine. In silico docking and screening, followed by chemical synthesis of a library of quinazolinones, led to the discovery of (E)-3-(3-carboxyphenyl)-2-(4-cyanostyryl)quinazolin-4(3H)-one (compound 2) as an antibiotic effective in vivo against methicillin-resistant Staphylococcus aureus (MRSA). This antibiotic impairs cell-wall biosynthesis as documented by functional assays, showing binding of 2 to penicillin-binding protein (PBP) 2a. We document that the antibiotic also inhibits PBP1 of S. aureus, indicating a broad targeting of structurally similar PBPs by this antibiotic. This class of antibiotics holds promise in fighting MRSA infections.

Infections caused by hard-to-treat methicillin-resistant Staphylococcus aureus (MRSA) are a serious global public-health concern, as MRSA has become broadly resistant to many classes of antibiotics. We disclose herein the discovery of a new class of non-β-lactam antibiotics, the oxadiazoles, which inhibit penicillin-binding protein 2a (PBP2a) of MRSA. The oxadiazoles show bactericidal activity against vancomycin- and linezolid-resistant MRSA and other Gram-positive bacterial strains, in vivo efficacy in a mouse model of infection, and have 100% oral bioavailability.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent multidrug-resistant pathogens worldwide, exhibiting increasing resistance to the latest antibiotic therapies. Here we show that the triple β-lactam combination meropenem/piperacillin/tazobactam (ME/PI/TZ) acts synergistically and is bactericidal against MRSA N315 and 72 clinical MRSA isolates in vitro, and clears MRSA N315 infection in a mouse model. ME/PI/TZ suppresses evolution of resistance in MRSA via reciprocal collateral sensitivity of its constituents. We demonstrate that these activities also extend to other carbapenem/penicillin/β-lactamase inhibitor combinations. ME/PI/TZ circumvents the tight regulation of the mec and bla operons in MRSA, the basis for inducible resistance to β-lactam antibiotics. Furthermore, ME/PI/TZ subverts the function of penicillin-binding protein 2a (PBP2a) action via allostery, which we propose as the mechanism for both synergy and collateral sensitivity. Showing similar in vivo activity to linezolid, ME/PI/TZ demonstrates that combinations of older β-lactam antibiotics could be effective against MRSA infections in humans.