Background-Regenerative gene therapy using viral vectors enables transduced cells to express bioactive factors in vivo. Viral delivery with spatial control can enhance transduction efficiency and avoid systemic infection. Consequently, we tethered biotinylated adenovirus via interactions with avidin on chitosan surfaces to gain robust control for in situ transduction.

To spatially control the delivery of multiple viral vectors from biomaterial scaffolds, digoxigenin (DIG) was conjugated to adenoviral capsid proteins as an antigenic determinant for antibody immobilization. The infectivity, toxicity, specificity and immobilization stability of DIG-modified adenovirus were examined to investigate the feasibility and effectiveness of this viral surface modification. Anti-DIG antibody conjugated on chitosan surfaces was able to immobilize DIGmodified adenovirus and could be stably bound on the material for at least two weeks, yet the modification was mild enough that viral infectivity was maintained. To immobilize two different adenoviruses, wax masking was applied to conjugate anti-DIG and anti-adenovirus antibodies in two discrete regions of a chitosan film, respectively. The distribution of these two viral vectors expressing different reporter genes was examined after cell culture. Fluorescent protein expression from transduced cells illustrated that the infection distribution could be controlled: one gene was delivered to the entire region of the biomaterial, and another was only delivered to defined regions. Compared to three other cardiac glycosides, ATPase inhibition was undetectable when DIG was conjugated on the adenovirus, suggesting that the method may be safe for in vivo application. This dual viral vector delivery system should be capable of generating distinct interfaces between cell signaling viruses to control tissue regeneration from a range of different biomaterials.

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