Compliant Surgical Adhesive

Surgical adhesives that include a blend of two different thermoreversible gelling polymers and a crosslinking agent are described. The first thermoreversible gelling polymer is partially or fully acrylated and the second thermoreversible gelling polymer includes dual functionality including acrylate functionality and amine-reactive functionality. The adhesives can provide gelling and covalent crosslinking within the polymers of the adhesive as well as crosslinking with surrounding tissue

An Exploratory Pathways Analysis of Temporal Changes Induced by Spinal Cord Injury in the Rat Bladder Wall: Insights on Remodeling and Inflammation

Background: Spinal cord injuries (SCI) can lead to severe bladder pathologies associated with inflammation, fibrosis, and increased susceptibility to urinary tract infections. We sought to characterize the complex pathways of remodeling, inflammation, and infection in the urinary bladder at the level of the transcriptome in a rat model of SCI, using pathways analysis bioinformatics. Methodology/Principal Findings: Experimental data were obtained from the study of Nagatomi et al. (Biochem Biophys Res Commun 334: 1159). In this study, bladders from rats subjected to surgical SCI were obtained at 3, 7 or 25 days post-surgery, and Affymetrix GeneChip® Rat Genome U34A arrays were used for cRNA hybridizations. In the present study, Ingenuity Pathways Analysis (Ingenuity® Systems, www.ingenuity.com) of differentially expressed genes was performed. Analysis of focus genes in networks, functional analysis, and canonical pathway analysis reinforced our previous findings related to the presence of up-regulated genes involved in tissue remodeling, such as lysyl oxidase, tropoelastin, TGF-β1, and IGF-1. This analysis also highlighted a central role for inflammation and infection, evidenced by networks containing genes such as CD74, S100A9, and THY1. Conclusions/Significance: Our findings suggest that tissue remodeling, infection, inflammation, and tissue damage/ dysfunction all play a role in the urinary bladder, in the complex response to SCI. © 2009 Wognum et al

An Exploratory Pathways Analysis of Temporal Changes Induced by Spinal Cord Injury in the Rat Bladder Wall: Insights on Remodeling and Inflammation

Abstract Background: Spinal cord injuries (SCI) can lead to severe bladder pathologies associated with inflammation, fibrosis, and increased susceptibility to urinary tract infections. We sought to characterize the complex pathways of remodeling, inflammation, and infection in the urinary bladder at the level of the transcriptome in a rat model of SCI, using pathways analysis bioinformatics

Application of Elastomeric Polymers for Bladder Regeneration

The urinary bladder is one of the few organs that has been successfully engineered and implanted in humans for a long-term clinical trial .However; scaffolds such as PGA-collagen used in the previous studies possess inadequate mechanical properties for organs that exhibit large deformation. The present study explored the use of biodegradable elastomers, poly-glycerol sebacate-polycaprolactone (PGS-PCl), poly (ether-urethane) urea (PEUU), and poly (carbonate-urethane) urea (PCUU) for urinary bladder tissue engineering since these materials have previously been shown to exhibit high extensibility and cytocompatibility. The present study compared mechanical properties of PGS-PCL, PEUU& PCUU elastomers. PGS-PCL, PEUU and wet PCUU specimens were subjected to uni-axial tensile loads under hydrated conditions (PBS at 37ºC) at a rate of 18mm/min until rupture using MTS synergie 100. The mechanical behaviors of these materials were analyzed by comparing the maximum tensions and stretch ratios at failure. The Mechanical characterization indicated that the PCUU may be more suitable for the bladder tissue engineering application than PEUU and PGS-PCL. Further studies, characterizing the stiffness of PCUU sutured rat bladders are currently underway using a custom-made in-vitro pressure-volume device

Construction of a corresponding empirical model to bridge thermal properties and synthesis of thermoresponsive poloxamines

The thermoresponsive properties of poloxamine (tetra-branch PEO-PPO block copolymer) hydrogels are related to several variables. Of particular interest to this study were the molecular weight of the polymer, the molar ratio between PEO and PPO blocks, and the concentration of the aqueous solution. Accurately controlling the thermoresponsive behaviors of the polymer is critical to the application of such materials; therefore, the structure–property relationship of tetra-branch PEO-PPO block copolymer was studied by synthesis via anionic ring-opening polymerization (AROP). The structure–property relationships were studied by measuring the thermoresponsive behavior via differential scanning calorimetry (DSC) and developing an empirical model which statistically fit the collected data. This empirical model was then used for designing poloxamines that have critical micellization temperatures (CMT) between room temperature and physiological temperature. The model was validated with three polymers that targeted a CMT of 308 K (35°C). The empirical model showed great success in guiding the synthesis of poloxamines showing a temperature difference of less than 3 K between the predicted and the observed CMTs. This study showed a great potential of using an empirical model to set synthesis parameters to control the properties of the polymer products