User:John M. Medley

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=John M. Medley=
=John M. Medley=
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<br>Following abdominal surgery, the internal wound healing can result in fibrous tissue deposits that connect adjacent tissues, resulting in formations called post-surgical adhesions (PSAs) [1, 2].  While often asymptomatic, these adhesions can lead to serious problems including bowel obstructions, chronic pain, and infertility.  In the United States, an estimated 440,000 adhesiolysis surgeries are conducted annually to correct issues arising from the formation of PSAs [3].
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To date, no satisfactory method has been developed to prevent all PSA types. While improvements in surgical techniques have reduced instances of PSA for some procedures, the most successful methods to prevent adhesions have relied on physical barriers that separate damaged tissue surfaces [4].  Current barriers methods are limited by the fact that the barriers must be applied directly to the area of damage.  This limitation precludes their application in laparoscopic surgeries and limits their effectiveness, as the damaged tissue cannot necessarily be identified or accessed by the physician during surgery.
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We hypothesize the development of a self-assembled polymer barrier based upon charge affinity for the site of exposed damaged tissue.  Since it will be applied as an aqueous solution, it is not necessary to know precisely the exact location of all damaged tissue areas and could potentially be used in both laparoscopic and the more invasive procedures.  Since this polymer includes ester linkages and relatively short chain segments (MW<10,000 g/mol), it will be bioerodible and readily cleared from the body.  Employing ionic interactions, the material targets the unique environment presented by damaged tissue and, by self-assembling at the site of injury, is expected to form a surface coating. Since polyethylene glycol is known to resist the adsorption of proteins and cells, this surface protection is anticipated to prevent the formation of post-surgical adhesions and facilitate normal healing of damaged tissues
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We have synthesized various copolymers of methacrylic acid and PEGylated methacrylic acid for investigation as adhesion barriers. We have previously demonstrated efficacy at reducing the adsorption of protein to model surfaces using block-copolymers. Current investigation focuses on the effect of polymer architecture and charge density on the affinity for model surfaces and the ability to prevent subsequent adsorption of proteins. 
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References
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1. Risberg, B., Adhesions: Preventive Strategies. European Journal of Surgery, Supplement, 1997. 577: p. 32-39.
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2. Ellis, H., et al., Adhesion-related Hospital Readmissions after Abdominal and Pelvic Surgery: A Retrospective Cohort Study. Lancet, 1996. 353.
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3. Matthews, B.D., el at, Assessment of Adhesion Formation to Intra-abdominal Polypropylene Mesh and Polytetrafluoroethylene Mesh. Journal of Surgical Research, 2003. 114(126-132).
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4. Boland, B.A.a.R.J.W., Formation and Prevention of Postoperative Abdominal Adhesions. Journal of Surgical Research, 2006. 132: p. 3-12.
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==Academic Experience and Education==
==Academic Experience and Education==
:<br>
:<br>

Revision as of 09:58, 20 March 2008

People

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  • DLS
  • Glovebox
  • Fluorimeter
  • Freeze Dryer
  • Uv-Vis
  • GPC/HPLC

Materials
Internal

Contact

John M. Medley
Mat and Chem Engineering
University of Kentucky
177 F Paul Anderson Tower
Lexington, KY 40506-0046
jmmedl0-at-engr.uky.edu

John M. Medley


Following abdominal surgery, the internal wound healing can result in fibrous tissue deposits that connect adjacent tissues, resulting in formations called post-surgical adhesions (PSAs) [1, 2]. While often asymptomatic, these adhesions can lead to serious problems including bowel obstructions, chronic pain, and infertility. In the United States, an estimated 440,000 adhesiolysis surgeries are conducted annually to correct issues arising from the formation of PSAs [3]. To date, no satisfactory method has been developed to prevent all PSA types. While improvements in surgical techniques have reduced instances of PSA for some procedures, the most successful methods to prevent adhesions have relied on physical barriers that separate damaged tissue surfaces [4]. Current barriers methods are limited by the fact that the barriers must be applied directly to the area of damage. This limitation precludes their application in laparoscopic surgeries and limits their effectiveness, as the damaged tissue cannot necessarily be identified or accessed by the physician during surgery. We hypothesize the development of a self-assembled polymer barrier based upon charge affinity for the site of exposed damaged tissue. Since it will be applied as an aqueous solution, it is not necessary to know precisely the exact location of all damaged tissue areas and could potentially be used in both laparoscopic and the more invasive procedures. Since this polymer includes ester linkages and relatively short chain segments (MW<10,000 g/mol), it will be bioerodible and readily cleared from the body. Employing ionic interactions, the material targets the unique environment presented by damaged tissue and, by self-assembling at the site of injury, is expected to form a surface coating. Since polyethylene glycol is known to resist the adsorption of proteins and cells, this surface protection is anticipated to prevent the formation of post-surgical adhesions and facilitate normal healing of damaged tissues We have synthesized various copolymers of methacrylic acid and PEGylated methacrylic acid for investigation as adhesion barriers. We have previously demonstrated efficacy at reducing the adsorption of protein to model surfaces using block-copolymers. Current investigation focuses on the effect of polymer architecture and charge density on the affinity for model surfaces and the ability to prevent subsequent adsorption of proteins.

References


1. Risberg, B., Adhesions: Preventive Strategies. European Journal of Surgery, Supplement, 1997. 577: p. 32-39. 2. Ellis, H., et al., Adhesion-related Hospital Readmissions after Abdominal and Pelvic Surgery: A Retrospective Cohort Study. Lancet, 1996. 353. 3. Matthews, B.D., el at, Assessment of Adhesion Formation to Intra-abdominal Polypropylene Mesh and Polytetrafluoroethylene Mesh. Journal of Surgical Research, 2003. 114(126-132). 4. Boland, B.A.a.R.J.W., Formation and Prevention of Postoperative Abdominal Adhesions. Journal of Surgical Research, 2006. 132: p. 3-12.


Academic Experience and Education


2006-Present
University of Kentucky, Lexington, KY
Ph.D. Candidate, Chemical Engineering
Expected Completion: June, 2009


2000
University of Kentucky, Lexington, KY
MS, Chemical Engineerin


1998
University of Michigan, Ann Arbor, MI
MS, Organic Chemistry

1996
Transylvania University, Lexington, KY
BA, Chemistry

1995
University of Chicago, Chicago, IL
NSF-REU Fellow

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  1. Paper1 pmid=6947258
  2. Paper2 pmid=13718526

// leave a comment about a paper here

  1. Book1 isbn=0879697164

</biblio>

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