Brian C. Ward

ABDOMINAL ADHESIONS: CURRENT AND NOVEL THERAPIES

An adhesion occurs when two tissues that normally freely move past each other attach via a fibrous bridge. Abdominal adhesions place a tremendous clinical and financial burden on public health. Adhesions develop after nearly every abdominal surgery, commonly causing female infertility, chronic pelvic pain, and, most frequently, small bowel obstruction. A National Hospital Discharge Survey of hospitalizations between 1998 and 2002 reported that 18.1% of hospitalizations were related to abdominal adhesions annually accounting for 948,000 days of inpatient care at an estimated cost of

Design of a bioactive cell-penetrating peptide: when a transduction domain does more than transduce.

1.18 billion. This review discusses the current or proposed therapies for abdominal adhesions. While many therapies for abdominal adhesions have been attempted, the need for a definitive therapy to prevent or even reduce abdominal adhesions still exists.

Peptide Inhibitors of MK2 Show Promise for Inhibition of Abdominal Adhesions

The discovery of cell‐penetrating peptides (CPPs) has facilitated delivery of peptides into cells to affect cellular behavior. Previously, we were successful at developing a phosphopeptide mimetic of the small heat shock‐like protein HSP20 . Building on this success we developed a cell‐permeant peptide inhibitor of mitogen‐activated protein kinase‐activated protein kinase 2 (MK2). It is well documented that inhibition of MK2 may be beneficial for a myriad of human diseases including those involving inflammation and fibrosis. During the optimization of the activity and specificity of the MK2 inhibitor (MK2i) we closely examined the effect of cell‐penetrating peptide identity. Surprisingly, the identity of the CPP dictated kinase specificity and functional activity to an extent that rivaled that of the therapeutic peptide. The results reported herein have wide implications for delivering therapeutics with CPPs and indicate that judicious choice of CPP is crucial to the ultimate therapeutic success. Published in 2009 by John Wiley & Sons, Ltd.

Cell penetrating peptides can exert biological activity: a review.

BACKGROUND Abdominal adhesions are a common side effect of surgical procedures with complications including infertility, chronic pain, and bowel obstruction, which may lead to the need for surgical lyses of the adhesions. Mitogen-activated protein kinase-activated protein kinase 2 (MK2) has been implicated in several diseases, involving inflammation and fibrosis. Thus, the development of a cell-penetrating peptide (CPP) that modulates MK2 activity may confer therapeutic benefit after abdominal surgery in general and more specifically after bowel anastomosis. METHODS This study evaluated the function of a CPP inhibitor of MK2 in human mesothelial cells and in a rat bowel anastomosis model. To determine IC50 and basic specificity, kinase inhibition was performed using a radiometric assay. Enzyme-linked immunoassay (ELISA) was used to evaluate interleukin-6 (IL-6) expression in response to IL-1β and tumor necrosis factor-α (TNF-α) stimulation in vitro to validate MK2 kinase inhibition. Following bowel anastomosis (10 rats for each control and treatment at 4 and 10 d), the rats were evaluated for weight loss, normal healing (colonic burst strength and hydroxyproline content at the anastomosis), and number and density of adhesions. RESULTS The IC50 of the MK2 inhibitor peptide (22 μM) was similar to that of the nonspecific small molecule rottlerin (IC50 = 5 μM). The MK2 inhibitor peptide was effective at suppressing IL-1β and TNF-α stimulated IL-6 expression in mesothelial cells. In vivo, the MK2 inhibitor peptide was effective at suppressing both the density and number of adhesions formed as a result of bowel an anastamosis. Importantly, the peptide had no negative effect on normal healing. CONCLUSIONS In conclusion, the peptide inhibitor of MK2, MMI-0100, has the potential to significantly reduce inflammation through suppression of inflammatory cytokine expression and showed promise as a therapeutic for abdominal adhesions.

Effect of Metal Substrate Nanometer Topography on Osteoblast Metabolic Activities

Abstract Cell penetrating peptides (CPPs) have been successful in delivering cargo into many different cell types and are an important alternative to other methods of permeation that might damage the integrity of the cell membrane. The traditional view of CPPs is that they are inert molecules that can be successfully used to deliver many cargos intracellularly. The goal of this review is to challenge this traditional understanding of CPPs. Recent literature has demonstrated that CPPs themselves can convey biological activity, including the alteration of gene expression and inhibition of protein kinases and proteolytic activity. Further characterization of CPPs is required to determine the extent of this activity. Research into the use of CPPs for intracellular delivery should continue with investigators being aware of these recent results.

INCREASED OSTEOBLAST AND DECREASED STAPHYLOCOCCUS EPIDERMIDIS FUNCTIONS ON NANOPHASE ZNO AND TIO2

Surgeons and bioengineers have continuously been challenged by implant failure. Many of these engineers and surgeons trace implant failure to poor osseointegration (the bonding of an orthopedic implant to juxtaposed bone) and to the inability of implants to match the physical properties of surrounding bone. Researchers have recently shown that nanostructured materials (or materials with fundamental length scales less than 100 nm) enhance cell functions pertinent to effectively regenerating the tissue of numerous organs. Specifically, in a recent study, researchers demonstrated that metal surfaces utilizing low-micron to nanophase topography fostered increased adhesion of osteoblasts, the cells that create the matrix of bone. In this study, Ti, Ti6Al4V, and CoCrMo alloys were investigated, and these alloys were identical to current orthopedic implant alloys except for surface topography. The objective of this in vitro research was to determine whether these same nanophase metal surfaces not only foster osteoblast adhesion but also increase osteoblast metabolic activities leading to bone regeneration. Light microscopy and Energy Dispersion Spectroscopy (EDS) were used to verify the presence of calcium and phosphorous deposition by osteoblasts cultured on the metal substrates. Results indicated that both calcium and phosphorous are being deposited on several of the metal substrates. More importantly, compared to conventional metals, results provided the first evidence that more calcium and phosphorous was deposited by osteoblasts cultured on respective nanophase metals (Ti, Ti6Al4V, and CoCrMo). Nanophase CoCrMo had the most calcium and phosphorous minerals deposited by osteoblasts compared to any other metal substrate. Thus, the results of this study continue to provide evidence for the use of nanophase metals for the design of the next generation of more successful orthopedic implants.