Implementation

Introduction

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OKstate iGEM’s project, Healios, aims to combine photodynamic light therapy with an engineered M13 bacteriophage capable of specifically binding to S. aureus. Phages carrying fused peptides for binding against various S. aureus surface structures will be chemically conjugated to the dye Rose Bengal. Wavelength-specific photodynamic light therapy will activate the photosensitizing dye after phages have specifically bound S. aureus, creating reactive oxygen species and lysing the pathogen while not harming other bacteria.

End-Users

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Healios started as an iGEM project created by undergraduate students, but the OKState team has a bigger goal than just competing for the iGEM competition. We envision that in the near future, Healios can be approved for use in clinics everywhere. We envision one day where a patient with a skin wound caused by nasty bugs such as MRSA can go into their nearest urgent care to be treated promptly (Figure 1). Healthcare workers trained in the use of the Healios system will apply S. aureus targeting and rose bengal conjugated M13 phage to the site of infection. Our Healios PDT lamp will then be used to activate the dye resulting in the targeted killing of the bacteria without damaging the patient’s surrounding tissue.

Current Challenges

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In-vitro Testing:

As we are still midway through the process, our current challenges to in-vitro testing include assembling the finished conjugated phage and testing its binding efficiency to S. aureus. Once the engineered M13 phage is completed, Healios will conduct trials to see if the phages bind and transfer the rose bengal dye successfully. The process will be monitored using phase contrast microscopy where we can see the movement and attachment periods displayed by the M13 phages. Some future challenges may include the amount of dye transferred to S. aureus and the ability of our engineered M13 phages to recognize S. aureus. Multiple S. aureus targeting peptides can be tested to determine which one has the best binding efficiency. Additionally, we plan to assess the efficiency of the LED lamp to activate the rose bengal dye and thus create the antibacterial reactive oxygen species. Some parameters to figure out include an effective exposure time to kill S. aureus and the proximity of the lamp to the bacteria.

In-vivo Testing:

Figure 1. Pre-clinical testing using animal models to test the effectiveness of Healios. (This figure was generated with ChatGPT and modified with Canvas GFX)

After in-vitro testing, Healios will test the product in-vivo. The trials include testing the M13 phage treatment on an animal model such as the nude mice model (Figure 1). We hope to assess the effectiveness and efficiency of our product to ensure a safe and viable treatment. The nude mice will acquire a skin infection containing S. aureus. Then, our phage-containing ointment will be applied to the infection and photo-dynamically treated with the Healios Lamp. These tests help determine the quality of the ointment on mammalian skin, the time-period needed for the phages to transfer the dye, and the proper exposure time from the lamp to effectively kill S. aureus and not cause damage to the mouse’s skin.

Clinical Trials and Bringing Healios to the Market

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After the completion of animal studies, we will begin applying to the FDA to conduct clinical trials. Our product is unique because it combines both a biologics (engineered phages) and a medical device (the PDT LED lamp). Therefore the process, although similar to other new drugs or medical devices, will differ somewhat from the traditional pathway.

1. Identifying which FDA center to lead the review of Healios

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• Request for Designation (RFD): We will submit an RFD to the FDA’s Office of Combination Products (OCP) for clarification on the regulatory path.

2. Regulatory Submissions

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• Investigational New Drug (IND) or Investigational Device Exemption (IDE): Based on the PMOA, the developer submits either an IND (for drug/biologic-led products) or an IDE (for device-led products) to initiate clinical trials.
• Premarket Approval (PMA), 510(k), or Biologic License Application (BLA): Depending on the product type, the eventual approval submission may vary. For example, a drug/biologic-led product may require a BLA, while a device-led product may require a PMA or 510(k).

3. Clinical Trials Phases

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• Phase 1: Safety and Dosage: Evaluate the safety of both the device and biotherapeutic components in a small group of healthy volunteers or patients. This phase focuses on potential side effects, drug-device interactions, and dosing.
• Phase 2: Efficacy and Side Effects: Test the combination product’s effectiveness in a larger patient group. This phase examines how well the drug/biologic works when delivered through the device and monitors for any side effects related to the combination.
• Phase 3: Large-Scale Testing: Conduct large-scale randomized trials to confirm the product's efficacy, monitor long-term safety, and compare the combination product to existing treatments. The device’s performance and the biotherapeutic effects are both analyzed to ensure they work well together.

4. Post-Trial and Regulatory Approval

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• New Drug Application (NDA)/Biologic License Application (BLA)/Premarket Approval (PMA): Submit a final regulatory application for approval. This submission includes all clinical trial data, device specifications, manufacturing processes, and labeling details.
• FDA Review and Advisory Committees: Depending on the complexity, the FDA may convene advisory panels of experts to review the combination product and provide recommendations.
• Labeling and Risk Management: The labeling for a combination product must clearly describe how the drug/biologic and device should be used together, including any special risks or handling instructions.

5. Post-Market Surveillance (Phase 4)

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• Even after approval, the combination product is monitored in the real world for long-term safety, performance, and effectiveness. If either the device or biotherapeutic exhibits any post-market issues, the manufacturer may need to address them with additional studies or changes to the product.

Figure 2. Schematic showing the process of testing Healios, a combination therapy product (device + biologics) in clinical trials and the eventual release of the product into the market.

Future Outlook

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Antibiotic resistance is a growing medical concern that pushes for new ways to treat infections. Our model utilizes an ointment of engineered, non-lytic phages and photodynamic therapy to effectively kill S. aureus and eliminate themselves in the process. This project will not contribute to the growing multidrug resistance of bacteria and will provide a quick and safe procedure to treat infections.

Safety

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Healios’ solution to treating multidrug-resistant bacterial infections requires both the retargeted M13 phages and the PDT lamp. We are aware of the fear some might have when they think of applying a layer of “viruses” onto their wound. A marketing team will need to educate the public as well as the healthcare providers that bacteriophages do not infect mammalian cells. Our phage system is also designed to be non-infective and targets only S. aureus or any other bacterial pathogens it’s been adapted into. Furthermore, when the Rose-Bengal dye is activated by the PDT lamp, the ROS generated will not only destroy the bacterial pathogens, but will also inactivate the phage particles as well. The LED lamp can also present some safety concerns if the lamp is being operated too long and burn the patient’s skin. During our pre-clinical and clinical testing, we will determine the optimal time to ensure this does not happen. Namely, we will determine the minimal exposure time required for Healios system to destroy the pathogens without damaging the patient. With Healios, we will strive to produce a novel alternative therapy to bacterial infections and we believe our system will also pose minimal safety concerns to both the operators (healthcare providers) and the end-users (patients).