Peptide Hydrogel Scaffold for Mesenchymal Precursor Cells Implanted to Injured Adult Rat Spinal Cord.

A unique, biomimetic self-assembling peptide (SAP) hydrogel, Fmoc-DIKVAV, has been shown to be a suitable cell and drug delivery system in the injured brain. In this study, we assessed its utility in adult Fischer 344 (F344) rats as a stabilizing scaffold and vehicle for grafted cells after mild thoracic (thoracic level 10 [T10]) contusion spinal cord injury (SCI). Treatments were as follows: Fmoc-DIKVAV alone, Fmoc-DIKVAV containing viable or nonviable rat mesenchymal precursor cells (rMPCs), and rMPCs alone. The majority of post-SCI treatments were administered at 11-15 days (mean 13.5 days) and the results then compared to SCI-only control (no treatment) rats. Postinjury behavior was quantified using open field locomotion (BBB) and LadderWalk analysis. After perfusion at 8 weeks, longitudinal spinal cord sections were immunostained with a panel of antibodies. Qualitatively, in the SAP-only treatment group, implanted gels contained regenerate axons as well as astrocytic, immune cell, and extracellular matrix (ECM) component profiles. Grafts of Fmoc-DIKVAV plus viable or nonviable rMPCs also contained numerous macrophages/microglia and ECM components, but astrocytes were generally confined to implant margins, and axons were rare. Quantitative analysis showed that, while average cyst size was reduced in all experimental groups, the decrease compared to SCI-only controls was only significant in the SAP and rMPC treatment groups. There was gradual improvement in functionality after SCI, but a consistent trend was only seen between the rMPC treatment group and SCI-only controls. In summary, after contusion SCI, implantation of Fmoc-DIKVAV hydrogel provided a favorable microenvironment for cellular infiltration and axonal regrowth, a supportive role that unexpectedly appeared to be compromised by prior inclusion of rMPCs into the gel matrix. Impact statement The self-assembling peptide hydrogel, Fmoc-DIKVAV, is a biomimetic scaffold that is an effective cell and drug delivery system in the injured brain. We examined whether this hydrogel, alone or combined with mesenchymal precursor cells, was also able to stabilise spinal cord tissue after thoracic contusion injury and improve morphological and behavioral outcomes. While improved functionality was not consistently seen, there was reduced cyst size and increased tissue sparing in some groups. There was regenerative axonal growth into hydrogels, but only in initially cell-free implants. This type of polymer is a suitable candidate for further testing in spinal cord injury models.

Evaluation and treatment of patients with cardiac disease undergoing bariatric surgery.

BACKGROUND: Bariatric surgery is a proven tool in reducing the co-morbidities associated with morbid obesity. The aim of the present review was to assess the current data and discuss the strategies for preoperative evaluation, preoperative treatment, and intraoperative management of the obese patient with cardiac disease seeking bariatric surgery, including those who have undergone previous angiographic intervention with coronary stenting and/or antiplatelet therapy. The setting was a university hospital in the United States. METHODS: A search of the English-language reports using the keywords morbid obesity, bariatric surgery, perioperative risk assessment, coronary artery disease, coronary stents, and antiplatelet therapy was conducted. RESULTS: The methods of preoperative cardiac risk assessment found in the published studies included the use of certain criteria, stress echocardiography, and single-photon emission computed tomography. Preoperative medical treatment optimization with ß-blockers and statins is recommended. Perioperative antiplatelet therapy in the form of aspirin 81 mg can be safely continued, but clopidogrel should be stopped and reinitiated with caution. CONCLUSION: Preoperative assessment of morbidly obese patients with coexisting cardiac issues presents unique challenges. Safe patient care and good clinical outcomes can be achieved with adherence to evidence-based practice.