by Robert Traynor, Ed. D., MBA, FNAP
It has been said that “Nanotechnology is an idea that most people simply do not believe.”
What is nanotechnology and how can it be applied to hearing care?
Nanoscience and nanotechnology are the study and application of nanoparticles undetectable by the human eye and made up of only a few hundred atoms and can be used across all science fields, such as chemistry, biology, physics, materials science, engineering, and medicine. Nanotechnology is revolutionizing many technology and industry sectors: information technology, homeland security, medicine, transportation, energy, food safety, and environmental science, among many others. Nanomedicine, then, is the application of nanotechnology to medical problems and disease. Nanomedicine draws upon the natural scale of biological phenomena to produce precise solutions for disease prevention, diagnosis, and treatment. One example of nanomedicine, and that which may soon have application for hearing care, is the delivery of drugs and therapy to parts of the body which have been impenetrable in the past.
Torrice (2016), described nanomedicine as the process of loading nanoparticles with drug molecules to assist compounds to stay in the blood longer and accumulate in tumors instead of in healthy tissue. Nanomedical delivery systems are a relatively new but a rapidly developing science where materials of nanoscale are employed to serve as means of delivering drugs or therapeutic agents to specific targeted sites in a controlled manner and offers multiple benefits in treating chronic human diseases by delivering site-specific, target-oriented payloads of precise medicines.
Commercialization of nanomedical delivery systems has been slow since the FDA first approved a medical device containing nanomaterials in 1980. In 2017, the FDA released draft guidance to accelerate approval for the use of these techniques. So let the games begin in the development of this revolutionary treatment technique.
Magnanoscience has been described in audiology literature by Depireux et al (2017), Kopke et al (2006) and Ramaswamy et al (2017) as a method of delivering drugs and treatment to former untouchable areas of the body, such as the audio-vestibular system and middle ear. While still in FDA trials, a magnanoscience procedure has the potential to reduce and possibly eliminate these disorders by the efficient delivery of medication to these difficult to reach areas.
Although becoming a reality, magnanoscience for hearing loss, otitis media, and cochlear regeneration sounds more like science fiction to audiologists and otolaryngologists, not to mention patients, but this system could be in routine use within the next couple of years.
New Methods in Drug and Therapeutic Delivery to the Auditory System
University of Maryland research has led to a company, Otomagnetics, who has been in the process of developing a non-invasive magnanoscience infusion method delivering drugs and other therapeutic payloads safely, effectively, and non-invasively to targets in the body that are currently not effectively reached by current standards-of-care, or that may otherwise require surgery.
Middle Ear Disorders
For children and adults with otitis media, antibiotics must be introduced orally or with an injection. Nanomedicine might be the answer to swiftly curing these episodes by allowing the medication to flow through the tympanic membrane, pulled by magnetic energy.
The magnetic induction idea puts the ear to be treated upwards and introduces the drugs into the ear canal, infusing the drugs through the eardrum into the middle ear, directly attacking the otitis media immediately.
Parents certainly know the feeling of helplessness while taking care of a child suffering the searing pain of otitis media, not to mention the hearing loss that accompanies effusion. In adults, otitis media can significantly affect hearing and work as well as be painful. When these patients have been treated with appropriate remediating antibiotics, it can still take time for the pain to resolve as the medication moves through their system and finally to the middle ear.
In chronic cases surgical treatment with tympanostomy tubes is often indicated to allow ventilation of the middle ear when other treatments are unsuccessful. This surgery may be avoided with more efficient presentation of medication.
Inner Ear Disorders
Drug and therapeutic treatment for audio-vestibular disorders within the otic capsule has been mostly prohibitive due to its location. The vestibular-cochlear structures are located deep in the temporal bone and behind vessels that supply blood to the inner ear. This blood-labyrinth barrier and deep location within the dense temporal bone are currently impermeable walls to most drug molecules and, therefore, has traditionally created major challenges to the delivery of drug therapy to treat inner ear disease.
The physical position of the structures reduces the efficacy of therapies meant to treat hearing loss, reverse tinnitus, and protect hearing from chemotherapy regimens such as Cisplatin, as well as the replenishment of antioxidants necessary for the survival of cochlear structures in noise and other traumatic conditions.
While trans-tympanic direct medication injection has been conducted through the cochlear round window to the cochlea, there is only limited diffusion of the medication to the injured areas.
No matter how new or novel a drug or therapeutic procedure, if it does not reach the inner ear in sufficient and effective quantities, it will not improve hearing loss, suppress tinnitus, alleviate vertigo, or reverse any of these conditions.
One significant study by Depireux et al (2017) described an experiment using Otomagnetic’s infusion method to counteract cisplatin administration. Cisplatin is a well-known ototoxic chemotherapy medication which likely causes the production of a reactive oxygen species in the inner ear space as well as the depletion of the inherent cochlear antioxidant system. These changes lead to apoptosis (a series of molecular steps that result in cell death) of hair cells in the organ of Corti, spiral ganglion cells, and marginal cells of the stria vascularis. In their experiment, Depireux and colleagues administered cisplatin regimens to mice causing hearing loss primarily at high frequencies.
In humans, hearing loss due to cisplatin is known to occur first at higher frequencies and then progress to lower frequencies as treatment continues (Rybak et al., 2009; Chirtes and Albu, 2014). Magnetic nano particles loaded with prednisolone and delivered via magnetic infusion through the round window of the cochlea mitigated the cisplatin induced ototoxicity at high frequencies with 95% statistical significance.
Other Areas of Treatment
The magnetic infusion is also beneficial for those with retinal disorders as currently these treatments are conducted by needle injections into the eye. Safer less painful and traumatic introduction of drugs and therapies for the eye can be conducted by magnetic infusion.
Further, certain skin disorders may be assisted with this technique.
Epilogue, Stardate 98887.39:
Nanoparticle based magnetic infusion is in the “not too distant” future. Currently, Otomagnetics researchers are finishing FDA toxicology protocols and they will fine tune the procedure and the packaging during 2022 and hope to be on the market in 2023.
While some would think efforts to move into new, unheard-of areas of research were a bit uncertain, others would consider it “Rocket Science.”
“Go boldly where no man has ever gone before.”
–Captain James T. Kirk, Starship Enterprise
References:
- Chirtes, F. & Albu, S (2014). Prevention and Restoration of Hearing Loss Associated with the use of Cisplatin. J. Biomedicine and Biotechnology 2014(3) Retrieved April 13, 2021 From https://www.researchgate.net/publication/264904714_Prevention_and_Restoration_of_Hearing_Loss_Associated_with_the_Use_of_Cisplatin
- Depireux, D., Ramaswamy, B., Shimoji, M., Shukoor, M., Benhal, P., & Shapiro, B.(2017). Magnetic Delivery of Therapy to the cochlea. Hearing Journal, Vol 70 (7), pp. 14, 16, 20.
- Kopke, R., Wassel,R., Grady,B., Chen, K., Jianzhong, L., Gibson, D., & Dormer (2006). Magnetic Nanoparticles Inner Ear Targeted Molecule Delivery and Middle Ear Implant. Audiology Neurotology, Vol 11, pp. 123-133.
- Ramaswamy, B., Roy, S., Apolo, A., Shapiro, B., & Depireaux, D. (2017). Magnetic Nanoparticle Mediated Steroid Delivery Mitigates Cisplatin Induced Hearing Loss. Front Cell Neuroscience. Vol 11, p.268.
- Rybak, L., Mukherjea, D., Jajoo,S., & Ramkumar, V. (2009). Cisplatin Ototoxicity and protection and Experimental Studies. Tohoku J. Exp. Med., Vol 219, pp. 2177-186.
