Development of a new therapeutic technique to direct stem cells to the infarcted heart using targeted microbubbles: StemBells.

Successful stem cell therapy after acute myocardial infarction (AMI) is hindered by lack of engraftment of sufficient stem cells at the site of injury. We designed a novel technique to overcome this problem by assembling stem cell-microbubble complexes, named 'StemBells'. StemBells were assembled through binding of dual-targeted microbubbles (~3µm) to adipose-derived stem cells (ASCs) via a CD90 antibody. StemBells were targeted to the infarct area via an ICAM-1 antibody on the microbubbles. StemBells were characterized microscopically and by flow cytometry. The effect of ultrasound on directing StemBells towards the vessel wall was demonstrated in an in vitro flow model. In a rat AMI-reperfusion model, StemBells or ASCs were injected one week post-infarction. A pilot study demonstrated feasibility of intravenous StemBell injection, resulting in localization in ICAM-1-positive infarct area three hours post-injection. In a functional study five weeks after injection of StemBells cardiac function was significantly improved compared with controls, as monitored by 2D-echocardiography. This functional improvement neither coincided with a reduction in infarct size as determined by histochemical analysis, nor with a change in anti- and pro-inflammatory macrophages. In conclusion, the StemBell technique is a novel and feasible method, able to improve cardiac function post-AMI in rats.

Cost-effectiveness in the management of Dupuytren's contracture. A Canadian cost-utility analysis of current and future management strategies.

In Canada, Dupuytren's contracture is managed with partial fasciectomy or percutaneous needle aponeurotomy (PNA). Injectable collagenase will soon be available. The optimal management of Dupuytren's contracture is controversial and trade-offs exist between the different methods. Using a cost-utility analysis approach, our aim was to identify the most cost-effective form of treatment for managing Dupuytren's contracture it and the threshold at which collagenase is cost-effective. We developed an expected-value decision analysis model for Dupuytren's contracture affecting a single finger, comparing the cost-effectiveness of fasciectomy, aponeurotomy and collagenase from a societal perspective. Cost-effectiveness, one-way sensitivity and variability analyses were performed using standard thresholds for cost effective treatment ($50 000 to $100 000/QALY gained). Percutaneous needle aponeurotomy was the preferred strategy for managing contractures affecting a single finger. The cost-effectiveness of primary aponeurotomy improved when repeated to treat recurrence. Fasciectomy was not cost-effective. Collagenase was cost-effective relative to and preferred over aponeurotomy at $875 and $470 per course of treatment, respectively. In summary, our model supports the trend towards non-surgical interventions for managing Dupuytren's contracture affecting a single finger. Injectable collagenase will only be feasible in our publicly funded healthcare system if it costs significantly less than current United States pricing.