In vivo performance of antibiotic embedded electrospun PCL membranes for prevention of abdominal adhesions

The aim of this study was to prepare nonwoven materials from poly(-caprolactone) (PCL) and their antibiotic containing forms by electrospinning, so as to prevent postsurgery induced abdominal adhesions in rats. -Caprolactone was first polymerized by ring-opening polymerization, and then it was processed into matrices composed of nanofibers by electrospinning. A model antibiotic (Biteral®) was embedded within a group of PCL membranes. In the rat model, defects on the abdominal walls in the peritoneum were made to induce adhesion. The plain or antibiotic embedded PCL membranes were implanted on the right side of the abdominal wall. No membrane implantation was made on the left side of the abdominal wall that served as control. Macroscopical and histological evaluations showed that using these barriers reduces the extent, type, and tenacity of adhesion. The antibiotic embedded membranes significantly eliminated postsurgery abdominal adhesions, and also improved healing

Quantitative analysis of late gadolinium enhancement in hypertrophic cardiomyopathy: comparison of diagnostic performance in myocardial fibrosis between gadobutrol and gadopentetate dimeglumine

The purpose of this study was to compare different semi-automated late gadolinium enhancement (LGE) quantification techniques using gadobutrol and gadopentetate dimeglumine contrast agents with regard to the diagnosis of fibrotic myocardium in patients with hypertrophic cardiomyopathy (HCM). Thirty patients with HCM underwent two cardiac MRI protocols with use of gadobutrol and gadopentetate dimeglumine. Contrast-tonoise ratio (CNR) between LGE area and remote myocardium (CNRremote), between LGE area and left ventricular blood pool (CNRpool), and signal-to-noise ratio (SNR) in LGE were compared. The presence and quantity of LGE were determined by visual assessment. With signal threshold versus reference mean (STRM) based thresholds of 2 SD, 5 SD, and 6 SD above the mean signal intensity (SI) of reference myocardium, the full-width at half-maximum (FWHM) technique was used. The volume and segments of the LGE area were compared between the two types of contrast agents. LGE was present in 26 of 30 (86.6%) patients in both protocols. The CNRremote of fibrotic myocardium in gadobutrol and gadopentetate dimeglumine agents was 26.82 ± 14.24 and 21.46 ± 10.59, respectively (P < 0.05). The CNRpool was significantly higher in gadobutrol (9.32 ± 7.64 vs. 6.39 ± 6.11, P < 0.05). The SNR was higher in gadobutrol (33.36 ± 14.35 vs. 27.53 ± 10.91, P < 0.05). The volume of scar size in MR images acquired with gadobutrol were significantly higher than those with gadopentetate dimeglumine (P < 0.05), and the STRM of 5 SD technique showed the greatest agreement with visual assessment (ICC = 0.99) in both examinations. There was no significant difference in fibrotic segments of the fibrotic myocardium in the LGE area (P < 0.05). This study proved that the Gadobutrol was an effective contrast agent for LGE imaging with superior delineation of fibrotic myocardium as compared to gadopentetate dimeglumine. The 5 SD technique yields the closest approximation of the extent of LGE identified by visual assessment

Review of journal of cardiovascular magnetic resonance 2010

There were 75 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2010, which is a 34% increase in the number of articles since 2009. The quality of the submissions continues to increase, and the editors were delighted with the recent announcement of the JCMR Impact Factor of 4.33 which showed a 90% increase since last year. Our acceptance rate is approximately 30%, but has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. Last year for the first time, the Editors summarized the papers for the readership into broad areas of interest or theme, which we felt would be useful to practitioners of cardiovascular magnetic resonance (CMR) so that you could review areas of interest from the previous year in a single article in relation to each other and other recent JCMR articles [1]. This experiment proved very popular with a very high rate of downloading, and therefore we intend to continue this review annually. The papers are presented in themes and comparison is drawn with previously published JCMR papers to identify the continuity of thought and publication in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication

In vivo tissue engineering of bone using poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) and collagen scaffolds

Porous poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) and calcium phosphate-loaded collagen (CaP-Gelfix) foams were seeded with rat bone marrow stromal cells and implanted into defects created in rat femurs to study in vivo bone formation and to test their suitability for use in bone tissue engineering. At 3 and 6 weeks, new bone formation was evaluated by macroscopy, radiography, dual-energy X-ray absorptiometry (DEXA), and quantitative computerized tomography (QCT). Atomic contents of the implants were further assessed by QCT. Some initial inflammation that significantly decreased with time was observed in the CaP-Gelfix group. PHBV inflammation was minimal at all stages. Fibrous tissue formation in the CaP-Gelfix group was more than in the PHBV group. Both cell-loaded and cell-free PHBV matrices elicited minimal fibrous tissue formation during the 6-week implantation duration. Macroscopic and radiological studies demonstrated better healing with PHBV matrices than with CaP-Gelfix in 3 weeks. Histologically, fibrous connective tissue establishment and inflammation scores were significantly higher in the CaP-Gelfix group when compared with the PHBV group at both time intervals. At 6 weeks, however, the extent of healing was almost the same with both implants. DEXA and QCT results indicated that there was an increase in bone mineral density in both PHBV and CaP-Gelfix implants at the end of 6 weeks. This study suggests that even though PHBV and CaP-Gelfix have different bulk and surface chemistries they both are promising cell carriers that may be suitable for use in bone tissue engineering

Development of a calcium phosphate-gelatin composite as a bone substitute and its use in drug release

This study was carried out to develop a calcium phosphate-gelatin composite implant that would mimic the structure and function of bone for use in filling voids or gaps and to release bioactive compounds like drugs, growth hormones into the implant site to assist healing. XDS analysis of the synthesized calcium phosphate revealed a calcium to phosphorus molar ratio of ca. 2.30, implying a less erodible material than hydroxyapatite (1.67). Release of the antibiotic gentamicin from the implant was with a burst, whether in situ or in vivo, followed by an almost constant release for about three months. It was found that the release rate could be decreased by increasing the density of the gelatin membrane. Upon implantation into rabbit tibia the release duration was substantially shortened (to about 4 weeks) with respect to the in situ tests basically due to the degradation of gelatin. In vivo studies with rabbits confirmed this degradation. The composite was perfectly biocompatible as shown by the histological studies. It, thus! has a great potential as a bone substitute material. (C) 1999 Published by Elsevier Science Ltd. All rights reserved

Bone generation on PHBV matrices: an in vitro study

Bone formation was investigated in vitro by culturing rat marrow stromal osteoblasts in biodegradable, macroporous poly(3-hydroxybutyric acid-co-3-bydroxyvaleric acid) (PHBV) matrices over a period of 60 days. Foams were prepared after solvent evaporation and solute leaching. PHBV solutions with different concentrations were prepared in chloroform: dichloromethane (1:2, v/v). In order to create a matrix with high porosity and uniform pore sizes, sieved sucrose crystals (300-500 mum) were used. PHBV foams were treated with rf-oxygen plasma (100W 10min) to modify their surface chemistry and hydrophilicity with the aim of increasing the reattachment of osteoblasts. Osteoblasts were isolated from rat bone marrow and seeded onto PHBV foams. The cell density on and in the foams was determined with MTS assay. NITS results showed that osteoblasts proliferated on PHBV. Twenty-one days after seeding of incubation, growth of osteoblasts on matrices and initiation of mineralization were observed by confocal laser scanning microscopy. Increasing ALP and osteocalcin secretion during 60 days confirmed the osteoblastic phenotype of the derived stromal cells. SEM, histological evaluations and confocal laser scanning microscopy showed that osteoblasts could grow inside the matrices and lead to mineralization. Cells exhibited spindle-like morphology and had a diameter of 10-30 mum. Based on these, it could confidently be stated that PHBV seems to be a promising polymeric matrix material for bone tissue engineering