Assessment of in vivo degradation profiles of hyaluronic acid hydrogels using temporal evolution of chemical exchange saturation transfer (CEST) MRI.

Hyaluronic acid (HA) hydrogels have found a wide range of applications in biomedicine: regenerative medicine to drug delivery applications. In vivo quantitative assessment of these hydrogels using magnetic resonance imaging (MRI) provides an effective, accurate, safe, and non-invasive translational approach to assess the biodegradability of HA hydrogels. Chemical exchange saturation transfer (CEST) is an MRI contrast enhancement technique that overcomes the concentration limitation of other techniques like magnetic resonance spectroscopy (MRS) by detecting metabolites at up to two orders of magnitude or higher.

Evaluating adhesion reduction efficacy of type I/III collagen membrane and collagen-GAG resorbable matrix in primary flexor tendon repair in a chicken model.

Background: Reduction of peritendinous adhesions after injury and repair has been the subject of extensive prior investigation. The application of a circumferential barrier at the repair site may limit the quantity of peritendinous adhesions while preserving the tendon's innate ability to heal. The authors compare the effectiveness of a type I/III collagen membrane and a collagen-glycosaminoglycan (GAG) resorbable matrix in reducing tendon adhesions in an experimental chicken model of a "zone II" tendon laceration and repair.

Remote efficacy for two different forms of hyaluronate-based adhesion barriers.

Background: Chemically modified sodium hyaluronate and carboxymethylcellulose (HA/CMC) membrane clinically reduces adhesion formation following surgery but was not designed for laparoscopic use. HA/CMC powder of identical chemical composition has been developed to allow for application laparoscopically. We compared the adhesion reduction efficacy of HA/CMC powder and film when applied directly to or remote from sites of surgical trauma.

Adhesion formation to hemostatic agents and its reduction with a sodium hyaluronate/carboxymethylcellulose adhesion barrier.

The impact of hemostatic agents on postoperative adhesion formation has not been well studied. We hypothesized that hemostatic agents would be a significant nidus for adhesion formation and that a resorbable barrier would effectively reduce adhesions to hemostatic agents. Four commercial hemostatic agents, each composed of a different biomaterial matrix, were implanted in female Sprague-Dawley rats, and adhesion formation was examined 7 days after surgery.

A membrane slurry reduces postoperative adhesions in rat models of abdominal surgery.

Background: Sodium hyaluronate and carboxymethylcellulose (HA-CMC) membrane is an effective barrier material for limiting postoperative adhesions, but can be difficult to apply in certain situations due to its physical properties. We tested whether HA-CMC membrane hydrated in saline (slurry) is an effective alternative to HA-CMC membrane for preventing surgical adhesions in rat models of abdominal surgery.

Materials And Methods: All studies were performed in rat cecal abrasion or sidewall defect models of adhesion formation.