Team:Lethbridge/Description
Amazing synthetic biology projects all have something in common. They need to deliver. Whether you are trying to cure a disease with a novel protein or small molecule, the last and most important step is delivering your innovations into cells. This is why we have focused on developing an innovative toolkit that utilizes Protein Nanocompartments (PNCs) in order to custom design a delivery strategy for iGEM teams and scientists that fits the needs of their projects.
Current Delivery Systems
Cellular delivery systems all share the same goal, to deliver cargo to a target. This cargo can be virtually anything! These may include nucleic acids such as plasmid DNA, small molecules such as chemotherapeutics, or proteins like the CRISPR-Cas9 system.
There are a wide range of cellular delivery systems available on today’s scientific markets. However, the perfect delivery system has not been developed and many of the most common technologies for cellular delivery used by the scientific community fall short.
| Criteria | Naked Molecules | Microinjection | Electroporation | Lipofection | Viral Transduction | Protein Nanocompartments |
|---|---|---|---|---|---|---|
| Efficient | X | ✔ | ✔ | X | ✔ | ✔ |
| Modular | X | X | X | X | / | ✔ |
| Specific | X | ✔ | X | ✔ | ✔ | ✔ |
| Safe for Organisms | / | X | X | ✔ | X | ✔ |
Why Protein Nanocompartments?
After consulting the literature and experts in the fields of biochemistry, industry, pharmacy, and clinical research, we determined that the ideal cellular delivery system would be one that has high delivery efficiency, modular compatibility with different cargo types, specific to appropriate targets, and safe for the public and the organism of choice. We strongly believe that PNCs meet those principles and have modeled our toolkit accordingly.
Protein nanocompartments (PNCs) are a nanoscale delivery system. They are composed of proteins that self-assemble to encapsulate various forms of cargo, like nucleic acids and small molecules, and deliver their cargo to different cellular and intercellular locations. Certain PNCs are able to target where they deliver their cargo with the use of surface peptides making them not only more specific, but also more efficient and can help limit off targeting effects when using PNCs to deliver therapeutic cargo (Rahovie et al., 2016). Due to their simple architecture, small size, and broad applicability, PNCs have the potential to become an extremely valuable tool for future iGEM teams and for the scientific community as well.
But where do PNCs come from? PNCs are derived from viruses. Viruses are comprised of a protein capsid, which house and transport a viral genome. In this case, the protein capsid is the PNC and the viral DNA is the cargo. However, PNCs as a cellular delivery system are not viruses! They are simply viral-inspired as they do not contain the viral genome necessary to replicate and cause harm and, in many cases, even their protein sequences have been modified for optimized delivery.
Figure 1. Overview of various virus-like particles (image from Rohovie et al., 2016).
Applications
Drug delivery: PNCs with the capacity to specifically target the delivery of their cargo through aid of surface peptides have the potential to dramatically enhance drug delivery and effectiveness in therapeutics. An example of this would be to decrease harmful side effects of chemotherapeutics by targeting their delivery specifically to cancer cells. Additionally, controlling the concentration of small molecules that can enter the cell by encapsulation can help drug delivery and prevent corresponding toxicity (Whitledge et al., 2015).
Targeted Cell Transformations and Transfections: PNCs with the ability to deliver cargo into the cellular membrane of their target cell have the potential to dramatically increase the efficiency of transforming bacterial cells or transfecting eukaryotic cells with plasmid DNA or other agents (Pastuzyn et al., 2018).
Targeted Antibiotic delivery: The side effects of antibiotic use include harming the host’s endogenous “good” bacteria along with their targeted “bad” bacteria may be circumvented by using PNCs to specifically target the “bad” bacteria with antibiotics (Kaur et al., 2016).
Vaccine development: PNCs have vast potential for the use of vaccines. Attaching linker sequences and other surface modifications to the capsid, as well as encapsulating immunogenic sequences can simplify the applications and productions of vaccines (Lua et al., 2015).
Gene therapy: By encapsulating a gene editing system like CRISPR, PNCs have the potential to deliver proteins capable of genetic modification to a specific tissue or population of cells. A benefit to targeted gene therapy is that it can help avoid genetic modification to all cells or even target gamete cells (Bundy et al., 2008).
Invasive Species/Pest Control: PNCs have the potential to encapsulate a toxic agent that may be specifically targeted to a particular species or pest while preventing off target effects within the ecosystem. Partnering this technology with specific biological control agents can help to prevent invasive species introduction and limit the proliferation of pests (Whitledge et al, 2015).
Implementation of iGEM projects: Our team did an analysis of previous projects in Alberta from The University of Alberta, The University of Calgary, The University of Lethbridge, and the Lethbridge high school. Of the projects analyzed, ~25% had trouble implementing their project into the real world scenario they had designed it for. Encapsulating in protein nanocompartments would allow them to deliver their systems safely and efficiently, making their projects more successful.
Our System
Our goal for the 2018 iGEM season was to develop a PNC toolkit for future iGEM teams and researchers which we named VINCEnT (Viral-Inspired Novel Cargo Encapsulation Toolkit). Our software tool was created in order to help individuals build PNCs that cater to their specific project needs which include surface peptides, encapsulation proteins, and specific cargo loading approaches that can be used for various applications. With these designs we can address a wide range of issues such as antibiotic resistance, the negative side-effects of chemotherapeutics, or the impact of using GMOs as biological control agents. For more information on VINCEnT, please visit our Design page.
Figure 2. VINCEnT's service: specific cargo is packaged and instructions are provided with the package for direct delivery to the desired cell type.