NANODIAMONDS

Tiny nanoparticles may offer a solution to one of the biggest problems in glaucoma treatment – poor patient compliance.

A new drug delivery system using nanoparticles embedded onto a contact lens may represent a major step forward in improving the management of glaucoma, suggest researchers at the University of California, Los Angeles (UCLA) School of Dentistry who created the new system. The glaucoma drugs are released into the eye when they interact with the patient’s tears. Researchers believe that their approach may entail less severe side effects than traditional glaucoma medication and improve patients’ ability to comply with their prescribed treatments.

In a recent study published in the journal ACS Nano, the new technology showed great promise for sustained glaucoma treatment and, as a side benefit, the nanodiamond-drug compound even improved the contact lenses’ durability, said lead author of the report Dean Ho PhD, MS, professor of oral biology and medicine and co-director of the Jane and Jerry Weintraub Center for Reconstructive Biotechnology at the UCLA School of Dentistry.

To deliver a steady release of medication into the eye, the UCLA researchers combined nanodiamonds with timolol maleate, which is commonly used in eye drops to manage glaucoma. When applied to the nanodiamond-embedded lenses, timolol is released when it comes into contact with lysozyme, an enzyme that is abundant in tears.

Prof Ho told EuroTimes that the study highlighted several advantages in using nanoparticles for drug delivery in glaucoma.

“The integration of nanodiamonds into the contact lens resulted in lysozyme-triggered drug release, improved mechanical robustness of the device, preserved water contact which is important for lysozyme access to mediate drug release and wear comfort, and practical clarity levels. In addition, the nanodiamonds are byproducts of conventional mining/refining processes and as such are sustainable nanomaterials,” he said.

Drawbacks

A drawback of traditional timolol maleate drops is that as little as five per cent of the drug reaches the intended site. Another disadvantage is burst release, where a majority of the drug is delivered too quickly, which can cause large amounts of the drug to spill out of the eye and, in serious cases, can cause complications such as an irregular heartbeat. Drops also can be uncomfortable to administer, which leads many patients to stop using their medication.

For patients with ocular surface disease, dry eye or other tear deficiencies which often co-exist in glaucoma patients, Prof Ho said the system could be potentially adapted to take account of individual patient characteristics. “Under these circumstances, other drugs or binding mechanisms could potentially be utilised that results in sustained drug delivery, where the nanodiamonds can be used as slow release matrices. We have previously harnessed potent nanodiamond-drug binding for sustained therapy against cancer,” he said.

After completion of initial preclinical studies within the next year or two, Prof Ho said that the next steps would be large animal validation studies followed by the first clinical studies in humans.

Dean Ho: dho@dentistry.ucla.edu