CRISPR–Cas gene editing and messenger RNA-based protein replacement therapy hold tremendous potential to effectively treat disease-causing mutations with diverse cellular origin. However, it is currently impossible to rationally design nanoparticles that selectively target specific tissues. Here, we report a strategy termed selective organ targeting (SORT) wherein multiple classes of lipid nanoparticles are systematically engineered to exclusively edit extrahepatic tissues via addition of a supplemental SORT molecule. Lung-, spleen- and liver-targeted SORT lipid nanoparticles were designed to selectively edit therapeutically relevant cell types including epithelial cells, endothelial cells, B cells, T cells and hepatocytes. SORT is compatible with multiple gene editing techniques, including mRNA, Cas9 mRNA/single guide RNA and Cas9 ribonucleoprotein complexes, and is envisioned to aid the development of protein replacement and gene correction therapeutics in targeted tissues. The addition of selective organ targeting molecules to nanoparticles allows the specific targeting of extrahepatic tissues, enabling gene editing of distinct cell populations outside the liver.

Selective organ targeting (SORT) nanoparticles for tissue-specific mRNA delivery and CRISPR–Cas gene editing

Genome editing, which involves the precise manipulation of cellular DNA sequences to alter cell fates and organism traits, has the potential to both improve our understanding of human genetics and cure genetic disease. Here I discuss the scientific, technical and ethical aspects of using CRISPR (clustered regularly interspaced short palindromic repeats) technology for therapeutic applications in humans, focusing on specific examples that highlight both opportunities and challenges. Genome editing is-or will soon be-in the clinic for several diseases, with more applications under development. The rapid pace of the field demands active efforts to ensure that this breakthrough technology is used responsibly to treat, cure and prevent genetic disease.

The promise and challenge of therapeutic genome editing

Advances in Experimental Medicine and Biology presents multidisciplinary and dynamic findings in the broad fields of experimental medicine and biology. The wide variety in topics it presents offers readers multiple perspectives on a variety of disciplines including neuroscience, microbiology, immunology, biochemistry, biomedical engineering and cancer research. Advances in Experimental Medicine and Biology has been publishing exceptional works in the field for over 30 years and is indexed in Medline, Scopus, EMBASE, BIOSIS, Biological Abstracts, CSA, Biological Sciences and Living Resources (ASFA-1), and Biological Sciences. The series also provides scientists with up to date information on emerging topics and techniques. 2015 Impact Factor: 1.953

https://ard.bmj.com/content/annrheumdis/55/11/796.3.full.pdf

Advances in experimental medicine and biology

Development of CRISPR as an Antiviral Strategy to Combat SARS-CoV-2 and Influenza.

The current global health threat by the novel coronavirus disease 2019 (COVID-19) requires an urgent deployment of advanced therapeutic options available The role of nanotechnology is highly relevant to counter this "virus" nano enemy Nano intervention is discussed in terms of designing effective nanocarriers to counter the conventional limitations of antiviral and biological therapeutics This strategy directs the safe and effective delivery of available therapeutic options using engineered nanocarriers, blocking the initial interactions of viral spike glycoprotein with host cell surface receptors, and disruption of virion construction Controlling and eliminating the spread and reoccurrence of this pandemic demands a safe and effective vaccine strategy Nanocarriers have potential to design risk-free and effective immunization strategies for severe acute respiratory syndrome coronavirus 2 vaccine candidates such as protein constructs and nucleic acids We discuss recent as well as ongoing nanotechnology-based therapeutic and prophylactic strategies to fight against this pandemic, outlining the key areas for nanoscientists to step in

Nanotechnology for COVID-19: Therapeutics and Vaccine Research.

Dysfunctional endothelium causes more disease than any other cell type. Systemically administered RNA delivery to nonliver tissues remains challenging, in large part because there is no high-throughput method to identify nanoparticles that deliver functional mRNA to cells in vivo. Here we report a system capable of simultaneously quantifying how >100 lipid nanoparticles (LNPs) deliver mRNA that is translated into functional protein. Using this system (named FIND), we measured how >250 LNPs delivered mRNA to multiple cell types in vivo and identified 7C2 and 7C3, two LNPs that efficiently deliver siRNA, single-guide RNA (sgRNA), and mRNA to endothelial cells. The 7C3 delivered Cas9 mRNA and sgRNA to splenic endothelial cells as efficiently as hepatocytes, distinguishing it from LNPs that deliver Cas9 mRNA and sgRNA to hepatocytes more than other cell types. These data demonstrate that FIND can identify nanoparticles with novel tropisms in vivo.

https://www.pnas.org/content/pnas/115/42/E9944.full.pdf

High-throughput in vivo screen of functional mRNA delivery identifies nanoparticles for endothelial cell gene editing.

Nanoparticles are often targeted to receptors expressed on specific cells, but few receptors are (i) highly expressed on one cell type and (ii) involved in endocytosis. One unexplored alternative is manipulating an endocytic gene expressed on multiple cell types; an ideal gene would inhibit delivery to cell type A more than cell type B, promoting delivery to cell type B. This would require a commonly expressed endocytic gene to alter nanoparticle delivery in a cell type-dependent manner in vivo; whether this can occur is unknown. Based on its microenvironmental regulation, we hypothesized Caveolin 1 (Cav1) would exert cell type-specific effects on nanoparticle delivery. Fluorescence was not sensitive enough to investigate this question, and as a result, we designed a platform named QUANT to study nanoparticle biodistribution. QUANT is 108× more sensitive than fluorescence and can be multiplexed. By measuring how 226 lipid nanoparticles (LNPs) delivered nucleic acids to multiple cell types in vivo in wild-...

/pdf/modifying-a-commonly-expressed-endocytic-receptor-retargets-55y0oqllk4.pdf

Modifying a Commonly Expressed Endocytic Receptor Retargets Nanoparticles in Vivo

The efficacy of nucleic acid therapies can be limited by unwanted degradation. Chemical modifications are known to improve nucleic acid stability, but the (i) types, (ii) positions, and (iii) numbers of modifications all matter, making chemically optimizing nucleic acids a combinatorial problem. As a result, in vivo studies of nucleic acid stability are time consuming and expensive. We reasoned that DNA barcodes could simultaneously study how chemical modification patterns affect nucleic acid stability, saving time and resources. We confirmed that rationally designed DNA barcodes can elucidate the role of specific chemical modifications in serum, in vitro and in vivo; we also identified a modification pattern that enhanced stability. This approach to screening chemical modifications in vivo can efficiently optimize nucleic acid structure, which will improve biomaterial-based nucleic acid drugs.

/pdf/barcoding-chemical-modifications-into-nucleic-acids-improves-2ax0hci3bt.pdf

Gwyneth N. Lando

Papers

High-throughput in vivo screen of functional mRNA delivery identifies nanoparticles for endothelial cell gene editing.

Modifying a Commonly Expressed Endocytic Receptor Retargets Nanoparticles in Vivo

Barcoding chemical modifications into nucleic acids improves drug stability in vivo