Alexandra L. Krisiewicz

Viral vectors such as adenovirus (Ad) and lentivirus (LV) are central to gene therapy owing to their transduction efficiency and broad applicability; however, their clinical translation is often limited by immunogenicity, rapid clearance, and reduced bioavailability. Non-enveloped Ad vectors are highly susceptible to neutralization by pre-existing antibodies, while enveloped LVs remain vulnerable to immune surveillance and off-target clearance. In this study, a biomimetic encapsulation strategy using erythrocyte-derived membranes (EDMs) is reported to enhance viral immune resilience and functional gene delivery. Ad-GFP and LV-mCherry were successfully encapsulated within EDM using an extrusion-based assembly approach, resulting in uniform membrane-coated particles with physicochemical properties characteristic of erythrocyte membranes. EDM encapsulation significantly enhanced in vitro transduction efficiency of both viral platforms across multiple cancer cell lines without compromising viral activity. Notably, EDM-Ad-GFP demonstrated robust protection against neutralizing antibodies, achieving significantly higher transduction of HEK293 cells in the presence of diluted human serum compared to unencapsulated Ad. These findings indicate that EDM encapsulation can effectively shield viral vectors from immune recognition while improving cellular uptake and transduction performance. Collectively, this work establishes EDM encapsulation as a versatile and scalable platform to enhance the efficacy, durability, and translational potential of viral gene delivery systems.

Oncolytic viruses have emerged as a promising modality in cancer treatment given their high synergy with highly efficient immune checkpoint inhibitors. However, their potency is limited by their rapid in vivo clearance. To overcome this, we coated oncolytic vaccinia viruses (oVV) with erythrocyte-derived membranes (EDMs), hypothesizing that they would not only remain in systemic circulation for longer as erythrocytes would when administered intravenously, but also respond to environmental pH cues due to their membrane surface sialic acid residues. For this, we developed a model based on DLVO theory to show that the acidic moieties on the surface of EDM confers it the ability to respond to pH-based stimuli. We corroborate our modeling results through in vitro cell culture models and show that EDM-coated oVV infects cancer cells faster under acidic conditions akin to the tumor microenvironment. When EDM-coated oVVs were intravenously injected into wild-type mice, they exhibited prolonged circulation at higher concentrations when compared to the unprocessed oVV. Furthermore, when EDM-coated oVV was directly injected into xenografted tumors, we observed that they were suppressed earlier than the tumors that received regular oVV, suggesting that the EDM coating does not hinder oVV infectivity. Overall, we found that EDM was able to serve as a multi-functional encapsulant that allowed the payload to remain in circulation at higher concentrations when administered intravenously while simultaneously exhibiting pH-responsive properties.