News Column

Reports from University of Toronto Highlight Recent Findings in Extracellular Matrix Proteins

June 20, 2014

By a News Reporter-Staff News Editor at Health & Medicine Week -- A new study on Proteins is now available. According to news reporting originating from Toronto, Canada, by NewsRx correspondents, research stated, "Collagen is the major structural protein of human dentin. Degradation of collagen by bacterial enzymes can facilitate microbial penetration, compromise structural/interfacial integrity, and lower resistance to fracture of dentin."

Our news editors obtained a quote from the research from the University of Toronto, "We evaluated the ability of photodynamic therapy (PDT), bioactive chitosan nanoparticles (CSnp), or PDT in combination with CSnp to inhibit bacterial collagenase-mediated degradation of collagen. Rat type 1 fibrillar collagen matrices were untreated or treated with 2.5% glutaraldehyde (GD), 2.5% GD followed by 1% CSnp, 1% CSnp, PDT (rose bengal activated with 540 nm light at 40 J/cm(2)), or 1% CSnp followed by PDT. Samples, except those used as untreated controls, were exposed to Clostridium histolyticum collagenase (125 CDU/mL) for 24 hours. The soluble digestion products were assessed by hydroxyproline assay, and the remaining adherent collagen was quantified by picrosirius red staining. Fourier transform infrared spectroscopy, immunoblotting, and scanning electron microscopy were used to study the interaction between CSnp/PDT with type 1 collagen. The data were analyzed by 1-way analysis of variance and post hoc Tukey test. As assessed by hydroxyproline release into the medium, collagen treated with CSnp, PDT, or a combination of CSnp and PDT exhibited less degradation than untreated controls (3.6-fold, 1.7-fold, and 7.9-fold reduction, respectively; P<.05). Compared with all other treatments, GD-treated collagen was the most resistant to collagenolytic degradation (239.6-fold reduction, P<.05). The abundance of posttreatment residual collagen, as measured by picrosirius red staining, was inversely related to the extent of collagen degradation. Analysis of collagen cross-links with Fourier transform infrared spectroscopy showed that PDT or GD treatments enhanced collagen cross-linking. Immunoblotting of sedimented CSnp indicated that CSnp and collagenase bound with low affinity. However, CSnp-bound collagenase showed a significant reduction in collagenolytic activity compared with controls (P < .05)."

According to the news editors, the research concluded: "Combined photochemical cross-linking of rat tail collagen by PDT and binding to CSnp inhibit collagenolytic activity."

For more information on this research see: Bioactive Chitosan Nanoparticles and Photodynamic Therapy Inhibit Collagen Degradation In Vitro. Journal of Endodontics, 2014;40(5):703-709. Journal of Endodontics can be contacted at: Elsevier Science Inc, 360 Park Ave South, New York, NY 10010-1710, USA. (Elsevier -; Journal of Endodontics -

The news editors report that additional information may be obtained by contacting A. Persadmehr, University of Toronto, Matrix Dynam Grp, Toronto, ON M5G 1G6, Canada. Additional authors for this research include C.D. Torneck, D.G. Cvitkovitch, V. Pinto, I. Talior, M. Kazembe, S. Shrestha, C.A. McCulloch and A. Kishen (see also Proteins).

Keywords for this news article include: Canada, Toronto, Ontario, Therapy, Collagen, Nanoparticle, Nanotechnology, Emerging Technologies, North and Central America, Extracellular Matrix Proteins

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Source: Health & Medicine Week

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