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food allergy test

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A Brief History of Molecularly Imprinted Polymers: The Heart of Allergy Amulet’s Technology

Dr. Joseph BelBruno, Scientific Advisor at Allergy Amulet.

Dr. Joseph BelBruno, Scientific Advisor at Allergy Amulet.

If you’ve been following our blog for a while, you’ve probably heard us talk about our scientific approach to detecting food allergens: molecularly imprinted polymer (MIP) films. These films lie at the technological heart of the Allergy Amulet. 

In a previous post, we covered the basics of how the technology works. Quick review: an MIP is a polymer (plastic) formed in the presence of target template molecules to create molecular molds. Once the templates are removed from our films, they leave behind trillions upon trillions of plastic molded “locks” that bind when in the presence of our molecular “keys.” In our films, these keys represent allergenic ingredients.

Today’s post looks at the history of MIP technology. While our science team has made considerable breakthroughs in the MIP field, we didn’t pull the foundation technology out of thin air. In fact, the body of work on MIPs dates back almost 100 years!

The first scientific mention of MIPs was back in 1931: a scientist named M. V. Polyakov discovered that when he made polymers out of silica in the presence of another molecule, the polymers would selectively absorb that molecule.

Some say the origins of MIP technology started with Jean Dickey at Cal Tech. He tried imprinting silica with organics back in 1949. The modern approach to imprinting began in Europe in the seventies and eighties with Klaus Mosbach in Sweden, Günter Wulff in Germany, Borje Sellegren in Amsterdam, and Karsten Haupt in France. These and other scientists developed many of the classic methods for creating imprinted polymers. Importantly, some studies found that in select circumstances, MIPs could imitate the functions of receptors, enzymes, and other biological molecules. 

After these initial discoveries, scientists identified new applications throughout the 20th century—mostly in drug separation—and you can currently buy MIP resins from leading science manufacturers like Sigma Aldrich. Yet, as with any nascent technology, development progressed slowly. Only in the past ten years have MIPs finally hit their stride: nearly half of all MIP papers were written in the past decade. Over time, researchers have optimized the conditions and techniques for developing MIPs, which has expanded the types of molecules MIPs are capable of imprinting. This has dovetailed with advancements in nanotechnology and communications technology. For example, the nanomaterials we use in our sensors were prohibitively expensive ten years ago. With these advancements, diverse commercial applications of MIP technology are finally becoming a reality.

For a detection device, successfully imprinting an allergenic ingredient (or any other target) is only half the battle.

Why is that? Well, even if an MIP can selectively bind the target molecule, it does so on a nanoscopic scale—we would have no way of knowing that binding occurred. Creating an MIP sensor accordingly requires a system that can translate that imprinting into something comprehensible (what scientists would call a transducer). While there has been significant research into different types of transducers for MIPs, a common approach has been electrical conductivity: an easily measured property that is already widely used in sensor technology.

There are several methods that convert successful imprinting to an electrical response. Two of the most popular methods involve using either conductive polymers or combining the MIPs with conductive nanomaterials.

Some of the first successes in creating conductive MIPs originated with Dr. Joseph BelBruno: a world-renowned chemist, Dartmouth chemistry professor, and Scientific Advisor at Allergy Amulet. Dr. BelBruno’s research laid the foundation for developing conductive MIP sensors. His work spawned the first commercial application of MIP sensors.

Allergy Amulet is positioned to become the second company to commercialize MIP sensors, and the first to create MIP sensors for detecting allergenic ingredients. Our sensors combine MIPs with an electrical response to create sensors for detecting molecular tracers of allergenic ingredients in food.

As with any novel application of an existing technology, it is important to recognize and pay tribute to the work of those before us. Learning and studying from the successes and failures of our predecessors is how we will advance as a scientific community, and advance as a society.    

-      Nazir and the Allergy Amulet Team

 

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What To Expect When You’re Expecting…An Oral Food Challenge

My daughter, moments after finishing her first oral food challenge.

My daughter, moments after finishing her first oral food challenge.

This topic is pretty fresh in my mind as my daughter underwent an oral food challenge to macadamia nuts last week. In case you’re not familiar with an oral food challenge (OFC), or haven’t experienced one yet, let us fill you in.

Today, oral food challenges are considered the gold standard for food allergy diagnosis in children and adults alike. Skin prick and blood tests aid in diagnosis, but they are prone to error—false positives are not uncommon. You can read more about food allergy diagnosis methods in our blog Food Allergies Today: An Expert Q & A.

There are typically three reasons why you might do an oral food challenge:

1. You or your child tested positively for a food allergy but have never actually eaten the food.

2. You or your child tested positively for a food allergy and have eaten the food before with no symptoms.

3. To see if you or your child has outgrown a known food allergy.

An oral food challenge is usually held at your allergist’s office over a few-hour period. The allergist administers tiny amounts of the potential allergen in gradually increasing doses over a set period of time (usually 3-6 hours). In my experience, the whole challenge start to finish lasts around 4 hours. Once the full serving is administered, the doctor will typically observe the patient for a couple hours to monitor for signs or symptoms of an allergic reaction. If symptoms occur at any point during an OFC, the challenge stops and symptoms are treated immediately.

Importantly, not everyone is a good candidate for an OFC. According to allergist Dr. Jordan Scott, “when asthma is flaring or when patients are ill, we don’t challenge.”

Let’s talk about what to expect. First, block off the day, because even if the OFC is expected to last only a few hours, the experience can be emotionally draining and stressful. Being prepared and understanding the purpose and procedure is incredibly important! Below you’ll find a list of things to prepare ahead of time so you can tackle the challenge head on. 

Ask your allergist what he/she needs you to bring. He may ask you to provide the food for the challenge, or his office may provide the food (we’ve done both). If you’re providing the food, make sure you’ve done your homework to ensure it’s not processed in a shared facility or processed on a shared line with something else you’re allergic to. For example, when we challenged sesame a couple years ago, we ensured the hummus we brought wasn’t processed in a shared facility with nuts: my daughter’s other allergen. We didn’t want cross-contact playing a factor.

Ask your allergist what you should stop doing. Ask your allergist what medicines you need to stop taking before the challenge. Our allergist requires that we stop giving our daughter her daily antihistamines for seasonal allergies a few days before the challenge, as that could mask reaction symptoms during the OFC. Additionally, she cannot take any asthma medicine that day. However, if asthma symptoms start flaring, there’s a chance they’ll want to play it safe and reschedule your challenge anyway—clear communication with your allergist is key!

Bring lots of activities for entertainment. If the trial is for a child, I’ve found that new activities, games, and library books always help to hold their attention longer. Having a favorite stuffed “friend” or something that the child associates with comfort is helpful too. If you’re an adult, a good book and your favorite digital gadgets will probably suffice!

Pack safe snacks. If the challenge goes well, you may be at the allergist’s office for several hours. However, the tiny doses of food your allergist administers aren’t likely to fill you up ☺. We like to bring some of our daughter’s favorite tried and true snacks that we know are safe (another way to avoid bringing cross-contact into the equation!). Since the challenge is at an allergist’s office, and there will likely be patients in the near vicinity with food allergies, it’s an added bonus if you can bring foods that are free from the most common allergens: peanuts, tree nuts, fish, shellfish, wheat, egg, milk, and soy. I also bring disinfectant wipes in case the food spills so that I can clean it up properly for the next allergic patient. Good food allergy etiquette is important!

Bring your emergency medications. While this may seem unnecessary (hello, you’re at the allergist’s office ☺), it’s important. There’s always a small chance of a delayed reaction, and if that happens on the way home, you’ll want to have your epinephrine and antihistamines at the ready.

Stay calm. If you’re a parent accompanying a child to an OFC, it helps to remain calm if your child experiences an allergic reaction. “If a reaction occurs, it is important for parents to remain calm because children can pick up on the anxiety and feed on that,” allergist Dr. John Lee advises. If your child experiences a reaction, Dr. Lee also suggests that parents avoid calling it a “failed challenge” in front of their child, noting that “this can make a child feel as if they’ve somehow failed, or done something wrong.”

Leave the siblings at home. If the food challenge is for your child, it’s smart to leave any siblings at home so you can stay focused—especially in the event of an allergic reaction. Best-case scenario, your child doesn’t have a reaction and it ends up being quality time with your babe. If you’re an adult, you’ll still want to bring someone with you for support and to make sure you get home safely.

Set a course of action/next steps. Once the challenge is complete, talk to your allergist about next steps. If the challenge went well, make sure you know how to proceed with exposure to the food moving forward. If it didn’t, they may recommend future testing/follow up, and possibly strict avoidance of the food.

I hope you find these tips helpful! After experiencing my daughter’s first oral food challenge, I felt far better equipped to take on the second. In case you’re wondering, she passed her OFC to macadamia nuts! This is one nutritious food we can add back into her diet. Hooray!

If you’re interested in discussing oral food challenges further, let me know. We’ve been through several, so I know the ropes pretty well!

- Meg and the Allergy Amulet Team 

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