Genetically engineered cellular nanoparticles for biomedical applications

Abstract

In recent years, nanoparticles derived from cellular membranes have been increasingly explored for the prevention and treatment of human disease. With their flexible design and ability to interface effectively with the surrounding environment, these biomimetic nanoparticles can outperform their traditional synthetic counterparts. As their popularity has increased, researchers have developed novel ways to modify the nanoparticle surface to introduce new or enhanced capabilities. Moving beyond naturally occurring materials derived from wild-type cells, genetic manipulation has proven to be a robust and flexible method by which nanoformulations with augmented functionalities can be generated. In this review, an overview of genetic engineering approaches to express novel surface proteins is provided, followed by a discussion on the various biomedical applications of genetically modified cellular nanoparticles.

Keywords: Biomimetic nanoparticle; Cell membrane coating; Detoxification; Drug delivery; Genetic engineering; Immunotherapy.

Fig. 1.. Evolution of genetically modified cellular nanoparticles.

With their flexible design and the ability to custom-tailor their functionality, genetically modified cellular nanoparticles offer improvements over conventional therapeutic approaches for biomedical applications. Created with BioRender.

Fig. 2.. Fabrication of genetically modified cellular nanoparticles.

Wild-type cells are genetically engineered using either a viral vector, nonviral vector, or physical disruption. Cellular components such as the plasma membrane can then be harvested to fabricate cellular nanoparticles with enhanced functionalities. Created with BioRender.

Fig. 3.. CAR-T cell membrane-coated nanoparticles for anticancer phototherapy.

(A) T lymphocytes are engineered to express a CAR construct specific for an overexpressed hepatocarcinoma antigen. Membrane derived from these cells is then used to coat IR780-loaded mesoporous silica nanoparticles (IM), yielding the final CAR-T cell membrane-coated nanoformulation (CIM). (B) After intravenous injection, the CIM nanoformulation significantly increases intratumoral temperatures when exposed to near-infrared irradiation (NIR). (C) Intravenous administration of CIM with subsequent exposure to NIR significantly suppresses tumor growth. Adapted with permission [67]. Copyright 2020, Ivyspring International Publisher.

Fig. 4.. Engineered cell membrane-coated nanoparticles for inflammation targeting.

(A) Membrane derived from wild-type cells engineered to express VLA-4 is coated onto polymeric nanoparticles carrying dexamethasone (DEX). The resulting nanoparticles target the inflammatory marker VCAM-1 on vascular endothelial cells, thereby reducing local inflammation. (B) When administered intravenously, the VLA-4 expressing-nanoparticles (VLA-NP) target the lungs more efficiently than wild-type nanoparticles (WT-NP). (C) The toxicity of DEX is reduced upon encapsulation into VLA-NP (VLA-DEX-NP). (D) VLA-DEX-NP reduces proinflammatory cytokine production in an animal model of acute lung inflammation. Adapted with permission [59]. Copyright 2021, American Association for the Advancement of Science.

Fig. 5.. Engineered stem cell membrane-coated nanoparticles for ischemia treatment.

(A) The membrane from stem cells genetically engineered to express surface CXCR4 for ischemia targeting is used to coat VEGF-loaded nanoparticulate cores. (B) Intravenous administration of the engineered nanoparticles improves perfusion of ischemic limbs. (C) The improved perfusion due to the nanoparticles results in higher degrees of limb salvage. Adapted with permission [148]. Copyright 2018, Elsevier.

Fig. 6.. Engineered cell membrane-coated nanoparticles for cytosolic mRNA delivery.

(A) Cells are genetically modified for the surface expression of viral hemagglutinin (HA), which enables mRNA-loaded nanoparticles coated with the HA-expressing membrane (HA-mRNA-NP) to achieve endosomal escape after cellular uptake. (B,C) HA-mRNA-NP promote in vivo expression of a Cypridina luciferase-encoding payload after intranasal (B) or intravenous (C) administration. Adapted with permission [98]. Copyright 2021, Wiley-VCH.

Fig. 7.. Engineered OMVs as a versatile antigen display platform.

(A) SpyCatcher (SpC) and SnoopCatcher (SnC) are genetically introduced onto the surface of OMVs via fusion with cytolysin A (ClyA). Antigens labeled with SpyTag (SpT) or SnoopTag (SnT) can then be readily conjugated onto the surface of the OMVs. (B) Engineered OMVs expressing the MC38-related antigen Adpgk are able to significantly suppress tumor growth and improve survival in an MC38 tumor model. Adapted with permission [66]. Copyright 2020, Springer Nature.

Fig. 8.. Engineered cell membrane-coated nanoparticles for direct antigen presentation.

(A) Wild-type cancer cells are engineered to express a costimulatory signal alongside their native MHC-I antigens. Nanoparticles coated with the membrane derived from these engineered cells can generate anticancer immunity by directly activating tumor-specific T cells. (B) Prophylactic immunization with the engineered nanoparticles significantly slows tumor growth and improves survival in a murine cancer model. Adapted with permission [58]. Copyright 2020, Wiley-VCH.

Fig. 9.. Engineered cell vesicles for cancer immunotherapy via PD-1 blockade.

(A) The membrane from HEK293T cells engineered to express PD-1 is used to form nanovesicles, which are then loaded with 1-methyl-tryptophan (1-MT), an indoleamine 2,3-dioxygenase-1 inhibitor. (B) Therapeutic treatment of tumor-bearing mice with the genetically engineered nanovesicles carrying 1-MT (G7) suppresses tumor growth and improves survival compared to controls of saline (G1), wild-type nanovesicles (G2), free 1-MT (G3), empty engineered nanovesicles (G4), free 1-MT inhibitor with wild-type nanovesicles (G5), and free 1-MT with anti-PD-L1 (G6). (C) Treatment with the engineered nanovesicles carrying 1-MT generates a high intratumoral percentage of CD8⁺ T cells. Adapted with permission [60]. Copyright 2018, Wiley-VCH.

Fig. 10.. Engineered E. coli OMVs expressing heterologous A. baumannii antigens for vaccination.

(A) A. baumannii Omp22 is introduced onto the surface of E. coli OMVs through genetic fusion with the cytolysin A (ClyA) protein. (B) Vaccination with the engineered OMVs protects against A. baumannii infection, leading to reduced bacterial burden. Adapted with permission [200]. Copyright 2016, Springer Nature.