A matrix reservoir for improved control of non-viral gene delivery.
ABSTRACT Non-viral gene delivery suffers from a number of limitations including short transgene expression times and low transfection efficiency. Collagen scaffolds have previously been investigated as in vitro DNA reservoirs, which allow sustained release of genetic information. Efficient viral gene-transfer from these scaffolds has previously been demonstrated. However, due to concerns about the safety of viral gene therapy, the use of non-viral vectors may be preferable. In this study a DNA-dendrimer complex embedded in a cross-linked collagen scaffold was investigated as a reservoir for non-viral delivery. Elution from the scaffolds and transfection of seeded rat mesenchymal stem cells were used to evaluate the scaffold's ability to act as a reservoir for the complexes. Elution from the scaffolds was minimal after 2 days with a total of 25% of the complexes released after 7 days. Extended transgene expression after DNA-dendrimer complex delivery from the scaffolds in comparison to direct delivery to cells was observed. The elongated transfection period and relatively high levels of reporter gene expression are significant advantages over other non-viral gene therapy techniques. This platform has the potential to be an effective method of scaffold-mediated gene delivery suitable for in vitro and in vivo applications.
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ABSTRACT: Stem cell transplantation has been suggested as a treatment for myocardial infarction, but clinical studies have yet to demonstrate conclusive, positive effects. This may be related to poor survival of the transplanted stem cells due to the inflammatory response following myocardial infarction. To address this, a scaffold-based stem cell delivery system was functionalised with anti-inflammatory plasmids (interleukin-10) to improve stem cell retention and recovery of cardiac function. Myocardial infarction was induced and these functionalised scaffolds were applied over the infarcted myocardium. Four weeks later, stem cell retention, cardiac function, remodelling and inflammation were quantified. Interleukin-10 gene transfer improved stem cell retention by more than five-fold and the hearts treated with scaffold, stem cells and interleukin-10 had significant functional recovery compared to the scaffold control (scaffold: -10 ± 7%, scaffold, interleukin-10 and stem cells: +7 ± 6%). This improved function was associated with increased infarcted wall thickness and increased ratios of collagen type III/type I, decreased cell death, and a change in macrophage markers from mainly cytotoxic in the scaffold group to mainly regulatory in scaffold, stem cells and interleukin-10 group. Thus, treatment of myocardial infarction with stem cells and interleukin-10 gene transfer significantly improved stem cell retention and ultimately improved overall cardiac function.Biomaterials 11/2011; 33(5):1303-14. · 8.31 Impact Factor
- New Strategies to Advance Pre/Diabetes Care: Integrative Approach by PPPM, 01/2013; Springer Publisher., ISBN: 978-94-007-5970-1
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ABSTRACT: Non-viral gene delivery is emerging as a realistic alternative to the use of viral vectors with the potential to have a significant impact on clinical therapies. The documented dangers of using the efficient recombinant viruses as carriers have led many to explore the possible advantages of using polymer-based non-viral vectors. To date there is no gene delivery vehicle that contains all the desirable characteristics but they do exist individually in a variety of non-viral carriers, e.g. degradable, low toxicity, cell specific, relatively efficient and capable of delivering multiple genes. Polymers may not be as effective as the viral vehicles; however, the continued focus and growth of knowledge in this field has already resulted in improved delivery. Over the past 10 years, significant progress has been made through the design of specific polymers for this application. Another interesting development in this field is the influx of research on combination approaches to non-viral gene delivery. Scaffolds made of both natural and synthetic materials are being utilized to aid in sustained delivery of the polymer vectors. While the non-viral gene therapy field is currently receiving a large degree of dedicated research there is now the realistic potential of a clinically relevant output. This review presents a summary of combinatorial delivery systems of non-viral polyplexes delivered via tissue engineered scaffolds. For polyplexes to move into the clinical arena, it is important that we uncover and understand the technical hurdles that need to be overcome so that the efficacy of this promising technology can be established.Progress in Polymer Science. 01/2010;