A Pilot Study to Determine the Impact of Adipose Tissue Attachment to Polypropylene Fibers In Hernia Mesh.

INTRODUCTION: Prior publications have demonstrated chemical and physical alteration of hernia mesh analyzed after explantation from the body. The specific alteration documented is oxidative degradation of polypropylene mesh fibers. An animal study recently published has demonstrated that adipose tissue attachment is present instead of reparative fibrous tissue infiltration in an average of 10.9-18.9% of the intramesh healing for a variety of clinically used knitted polypropylene mesh products; 8.0% for knitted polyester meshes. This study also found that in comparison to the knitted mesh products, non-woven polypropylene mesh reduced adipose tissue attachment to 1% or less, which was a statistically significant difference. MATERIALS AND METHODS: Samples of explanted polypropylene mesh from eight patients were analyzed for the presence of adipose tissue attachment, reparative fibrous tissue infiltration, and oxidative changes. Greater adipose tissue attachment areas were compared with areas of greater reparative fibrous tissue infiltration for evidence of oxidative changes in the mesh to determine if the areas of higher adipose tissue attachment correlated with an increase in oxidative changes. RESULTS: Intra mesh healing of clinically explanted knitted meshes demonstrated adipose tissue content from 0.0% to 49.1% per analyzed segment. The oxidation index, a measure of the degree of oxidative degradation in that portion of the mesh, was higher in seven of the eight areas of greater adipose tissue attachment than areas of greater reparative fibrous tissue infiltration. CONCLUSION: Adipose tissue attachment does occur in knitted and woven polypropylene hernia meshes. The presence of adipose tissue may contribute to an increase in oxidative changes in knitted polypropylene hernia mesh fibers.

A comparison of proteomic, genomic, and osteological methods of archaeological sex estimation.

Sex estimation of skeletons is fundamental to many archaeological studies. Currently, three approaches are available to estimate sex-osteology, genomics, or proteomics, but little is known about the relative reliability of these methods in applied settings. We present matching osteological, shotgun-genomic, and proteomic data to estimate the sex of 55 individuals, each with an independent radiocarbon date between 2,440 and 100 cal BP, from two ancestral Ohlone sites in Central California. Sex estimation was possible in 100% of this burial sample using proteomics, in 91% using genomics, and in 51% using osteology. Agreement between the methods was high, however conflicts did occur. Genomic sex estimates were 100% consistent with proteomic and osteological estimates when DNA reads were above 100,000 total sequences. However, more than half the samples had DNA read numbers below this threshold, producing high rates of conflict with osteological and proteomic data where nine out of twenty conditional DNA sex estimates conflicted with proteomics. While the DNA signal decreased by an order of magnitude in the older burial samples, there was no decrease in proteomic signal. We conclude that proteomics provides an important complement to osteological and shotgun-genomic sex estimation.

A novel crosslinker-free technique toward the fabrication of collagen microspheres.

Injectable collagen microspheres (CMs) have the potential to be an excellent tool to deliver various modulatory agents or to be used as a cellular transporter. A drawback has been the difficulty in producing reliable and spherical CMs. A crosslinker-free method to fabricate CMs was developed using liquid collagen (LC) in a water-in-oil emulsion process with varying concentrations of surfactant span-80. Different emulsion times of up to 16-hr were utilized to produce the CMs. Visual microscopy and scanning electron microscopy were utilized to determine the morphology of the CMs. To determine the fibril nature of the CMs, focus ion beam milling, energy dispersive spectroscopy, and Fourier Transformation-Infrared spectroscopy were performed. A cell biocompatibility study was performed to assess the biocompatibility of the CMs. The results demonstrated that consistent spherical CMs were achievable by changing the span-80 concentration. The CMs were fibrilized not only at the surface, but also at the core. Both the 1- and 16-hr emulsion time demonstrated biocompatibility and it appeared that the cells preferentially adhered to the CMs. This crosslinker-free method to fabricate CMs resulted in spherical, stable, biocompatible CMs, and could be an excellent technique for multiple tissue engineering applications.