Scaffold-mediated delivery for non-viral mRNA vaccines

Abstract

mRNA is increasingly being recognized as a promising alternative to pDNA in gene vaccinations. Only recently, owing to the needs of cancer immunotherapies, has the biomaterials/gene delivery community begun to develop new biomaterial strategies for immunomodulation. Here, we report a novel way to use implantable porous scaffolds as a local gene delivery depot to enhance mRNA vaccine immunization in vitro, and in vivo when compared with conventional bolus injections. We first evaluated transfection efficiencies of single-stranded mRNA condensed and charge neutralized with two lipids (Lipofectamine Messenger MAX™ LM-MM and Stemfect™ SF) and two cationic polymers (in vivo-jetPEI™, Poly (β-amino ester)) as gene carriers. As SF demonstrated highest in vitro transfection and cell viability, it was selected for subsequent porous polymer scaffold-loading trials. Enhanced in vitro transfection of SF:mRNA nanoparticle-loaded poly (2-hydroxyethyl methacrylate) (pHEMA) scaffolds was also observed with a DC2.4 cell line. Improved sustained local release and local transgene expression were also demonstrated with SF:mRNA nanoparticle-loaded pHEMA scaffolds in vivo compared with bolus injections. Our results suggest that mRNA polyplex-loaded scaffolds may be a superior alternative to either repeated bolus immunizations or ex vivo transfection cell immunotherapies.

Injectable Biodegradable Chitosan‐Alginate 3D Porous Gel Scaffold for mRNA Vaccine Delivery

“…We found that both carriers and scaffold served important roles in the improvement of local transfection in vivo 2 days post‐injection. Previous results from scaffold‐released mRNA vaccines demonstrated that dendritic cells are recruited into the scaffold, uptake mRNA lipoplexes, then migrate to draining lymph nodes for T cell stimulation to initiate an adaptive immune response …”

“…Previous results from scaffold-released mRNA vaccines demonstrated that dendritic cells are recruited into the scaffold, uptake mRNA lipoplexes, then migrate to draining lymph nodes for T cell stimulation to initiate an adaptive immune response. [41] Various nanoparticle systems have been developed for maintaining mRNA stability and bioactivity. In this study, an injectable scaffold platform was designed specifically for mRNA loading and it was combined with the standard mRNA lipoplex nanoparticle technology for mRNA vaccine delivery in vivo.…”

Establishing Preferred Product Characterization for the Evaluation of RNA Vaccine Antigens

“…Messenger RNA vaccines are composed of one or more nucleic acids encoding for a single or multiple vaccine antigen candidates, formulated in a delivery vehicle and then directly delivered into the host cell. These delivery vehicles include lipid-and protein-based molecules, as well as various types of polymeric scaffolding [2][3][4][5][6][7][8][9].…”

Faculty Opinions recommendation of Advances in mRNA Vaccines for Infectious Diseases.

“…Additional new modified nanoparticles are currently being investigated, such as polyplexes, nanoplexes and porous polymer scaffold-mediated delivery (116)(117)(118)(119)(120)(121)(122). Although great advances have been achieved in the development of delivery tools, the ideal platform maybe a combination of different mRNA delivery tools and more efforts in understanding mechanism of action might be required.…”