Genetic Engineering for Skeletal Regenerative Medicine

Abstract

The clinical challenges of skeletal regenerative medicine have motivated significant advances in cellular and tissue engineering in recent years. In particular, advances in molecular biology have provided the tools necessary for the design of gene-based strategies for skeletal tissue repair. Consequently, genetic engineering has emerged as a promising method to address the need for sustained and robust cellular differentiation and extracellular matrix production. As a result, gene therapy has been established as a conventional approach to enhance cellular activities for skeletal tissue repair. Recent literature clearly demonstrates that genetic engineering is a principal factor in constructing effective methods for tissue engineering approaches to bone, cartilage, and connective tissue regeneration. This review highlights this literature, including advances in the development of efficacious gene carriers, novel cell sources, successful delivery strategies, and optimal target genes. The current status of the field and the challenges impeding the clinical realization of these approaches are also discussed.

Anatomically shaped tissue-engineered cartilage with tunable and inducible anticytokine delivery for biological joint resurfacing

“…Previous scaffoldmediated gene delivery approaches include release of encapsulated vectors from within a biomaterial as it degrades (50,51) or immobilization on the scaffold surface to spatially control transduction (52,53). However, these strategies have primarily generated transient gene expression by delivering plasmid DNA (50,51) or nonintegrating viral vectors (52,54).…”

“…For scaffold-mediated transduction, PCL hemispheres were coated in 0.002% poly-L-lysine (PLL) (Sigma-Aldrich) overnight. PLL is a cationic polymer that helps immobilize negatively charged viral vectors to the PCL scaffold (53,59,63). Hemispheres were then rinsed in PBS (Gibco) and 200 μL of concentrated lentivirus containing an inducible expression cassette for IL-1Ra, or eGFP was added at a final biological titer of 6 × 10 6 transducing units per milliliter to each hemisphere.…”

Scaffold-mediated lentiviral transduction for functional tissue engineering of cartilage

“…As such, this technique for LV immobilization can be applied in the context of other PCL-based scaffolds and potentially using other materials than PCL. More importantly, it is possible that our approach to scaffold-mediated transduction could be extended to a variety of applications using numerous other cell types, transgenes, and drug-inducible promoters (69). When combined with the appropriate scaffold structure and material, we envision broad utility of this technique in the area of recapitulating the complex organization of heterogeneous tissues, such as osteochondral tissues, and in the delivery of therapeutic transgenes capable of mediating protection and repair of tissues in the context of a diseased or damaged joint.…”

Smooth grafts ahead

“…[2][3][4] Helen Lu, director of the Biomaterials and Interface Tissue Engineering Laboratory and an associate professor of biomedical engineering at Columbia University, also thinks graded interfaces can minimize the formation of areas with high concentrations of mechanical stress and will allow for a more efficient and gradual dissipation of these stressors. "This will reduce the possibility of mechanical failure, " she said.…”

“…2 Bruce Wentworth, senior scientific director at Genzyme Corp., thinks the approach in the PNAS article could lead to the creation of tissue constructs with more cell types and more complex cell distribution patterns that closely mimic native tissue.…”