MIT engineers are revolutionizing the way long-lasting drugs are administered, potentially transforming patient care for those needing sustained drug delivery. By developing a new method that could maintain drug release for months or even years from a single injection, this innovation offers a promising alternative to frequent injections. In a recent article published by MIT News, Giovanni Traverso, an MIT associate professor and the senior author of the study, shared, "We showed that we can have very controlled, sustained delivery, likely for multiple months and even years through a small needle."
The technique involves an injection of tiny crystal drug suspensions, forming a compact "depot" under the skin that slowly releases medication over time. Such a technology has particular implications for contraception in the developing world, where access to various administration methods is limited. "The overarching goal is to give women access to a lot of different formats for contraception that are easy to administer, compatible with being used in the developing world, and have a range of different timeframes of durations of action," Vivian Feig, former MIT and BWH postdoc, and now an assistant professor of mechanical engineering at Stanford University, told MIT News. The usual issue with existing injectable drugs, which disperse through the tissue and last around three months, is mitigated by this new formulation which requires less frequent administration.
At the core of this new solution is the use of a biocompatible solvent, benzyl benzoate, which enables the formation of a drug depot upon injection, facilitating the self-assembly of solid drug crystals, as detailed by MIT News. "The solvent is critical because it allows you to inject the fluid through a small needle, but once in place, the crystals self-assemble into a drug depot," explained Traverso. This depot can release drugs into the body at a rate which can be adjusted by tweaking the depot's density. By this method, lesser amounts of polymer than previously used solutions are required, maintaining ease of injection through a small-gauge needle.
Tests on rats demonstrated the long-term stability of these drug depots; researchers estimate the depots could potentially last over a year. "We anticipate that the depots could last for more than a year, based on our post-analysis of preclinical data," Sanghyun Park, an MIT graduate student and one of the lead authors of the study, remarked in the MIT News. An added benefit is the ability to retrieve the compact drug depots surgically, if needed, before the full dosage is released. Now, the team is focusing on advancing these studies into more clinically relevant environments, setting the stage for human applications in the future.
As research progresses, the potential applications encompass more than just contraceptives; this delivery system could extend to treatments for neuropsychiatric conditions and infectious diseases like HIV and tuberculosis. Funded in part by the Gates Foundation and a range of fellowships, the MIT team's work not only addresses the technical challenges of sustained drug delivery but also underscores the possibilities for improved drug access and compliance in populations across the globe.
