Fibrin hydrogels for lentiviral gene delivery in vitro and in vivo

Abstract

Gene delivery from hydrogels represents a versatile approach for localized expression of tissue inductive factors than can promote cellular processes that lead to regeneration. Lentiviral gene therapy vectors were entrapped within fibrin hydrogels, either alone or complexes with hydroxylapatite (HA) nanoparticles. The inclusion of HA into the hydrogel led to the formation of small aggregates distributed throughout the hydrogel, with no obvious alteration of the pore structure outside the aggregates. The presence of HA slowed hydrogel degradation by collagenase and plasmin relative to fibrin alone, and also decreased the rate of cell migration. Lentivirus had similar release from the fibrin hydrogels formed with or without HA. The altered hydrogel properties suggest an interaction between the nanoparticle and fibrin, which may displace the virus from the particle leading to similar release profiles. Transgene expression by cells migrating into the hydrogel in vitro was reduced in the presence of HA, consistent with the role of cell migration on transgene expression. In vivo, lentivirus loaded fibrin hydrogels promoted localized transgene expression that increased through day 9 and decreased through day 14. For the fibrin only hydrogels, expression continued to decline after day 14. However, hydrogels with HA maintained this transgene expression level for an additional two weeks before declining. Immunostaining identified transgene primarily outside the fibrin-HA gel at day 9; however, at day 21, transgene expression was observed primarily within the fibrin-HA gel. The localized delivery of lentivirus provides an opportunity to enhance the bioactivity of fibrin hydrogels for a wide range of applications in regenerative medicine.

Microfluidic generation of alginate microgels for the controlled delivery of lentivectors

“…Additionally, the reported mesh sizes may not completely prevent the transport of such particles through the mesh. 54,69,70 This measurement provides only an approximation of an idealized meshwork structure, and in reality does not account for network imperfections such as closed polymer loops, dangling ends, and slipping chain entanglements. 71 Interestingly, the profiles of lentivector release and cellular transduction suggest that the mode of gelation and extent of crosslinking may be important parameters in regulating lentivector delivery from microgels.…”

Stimuli-responsive hydrogels in drug delivery and tissue engineering

“…When tested against tumor induced by B16-Fo/neu tumor cells in mice, the alginate polylysine alginate (APA) microcapsules showed 80% reduction in tumor volume at day 21 (Li et al, 2006). Lentiviral gene therapy vectors can be entrapped within fibrin hydrogels alone or in complex form with hydroxylapatite (HA) nanoparticles, which provides an opportunity to enhance the bioactivity of fibrin hydrogels for a wide range of applications in regenerative medicine (Kidd et al 2011). Gene delivery of hydrogels incorporating biodegradable polymer is shown in Figure 7.…”

Evolving Lessons on Nanomaterial-Coated Viral Vectors for Local and Systemic Gene Therapy

“…Cationic nanoparticle-complexed virus are internalized into the cells through distinct charge interactions between the anionic cell surface and the cationic surface of the complex, thus enabling to transduce a wide range of cells with or without primary receptor for viral uptake [97,98]. Modification of viral vectors by nanomaterials Review gel can protect viral vectors from degradative enzymes and the host immune response [101,102]. Consequently, the sustained release of viral vectors from hydrogel can induce stable and sufficient transgene expression over prolonged periods of time [91].…”

“…Entrapment of a lentiviral vector within a hydrogel has the potential to increase the stability of the LV through protection from denaturing enzymes and the host immune system [101]. Shin et al investigated the potential of hydroxyapatite (HA) nanoparticle-incorporated collagen hydrogel loaded with LV to enhance long-term gene transfer [108].…”

“…Kidd et al demonstrated that addition of HA nanoparticles during the formation of fibrin hydrogel (fibrin-HA gel) enhanced lentiviral gene delivery in vitro and in vivo compared with fibrin gel lacking HA nanoparticles [101]. The presence of HA slowed collagenase-mediated hydrogel degradation in comparison to control fibrin gel, resulting in a lower rate of cell migration into the hydrogel.…”