Here is a very interesting technology targeted to the field of microsensors which appears to have potential in drug delivery. These so called “microworms” are currently made of a hydrogel material. The idea is that the microtubes will sit in place longer than other technologies such as micro or nano-beads. Filled with a drug they could act as a time release reservoir. As initially described if they are filled with an appropriate flourescent material the technology could be used as a transducer component of a chemical sensor system.
Other ideas come to mind. Because of the hydrogel technology interstitial fluid can diffuse into the tubules and under the right conditions dilute the drug. This might be used to advantage. Subcutaneous mechanically based drug delivery systems for long term drug delivery typically need to replenish their drug supply periodically. If targeted to a tissue the concentration of the drug has to be at the appropriate cellular concentration levels or it may damage the surrounding tissue. The dilute concentration requires that relatively large amounts of fluid may be stored subcutaneously unless frequent replenishment is acceptable. If the path of the hydrogel microtubules is long enough the possibility exists of creating as system that can use a higher concentration of drug thus reducing the volume or number of percutaneous injections required to replenish the reservoir.
Another concept that I believe is already in the marketplace but could be improved is to use the microworms as a sample collection tool. In this scenario the microworms internal fluid content would quickly come into equilibrium with the surrounding space it was inserted and the contents could be sampled. Microliters of the cerebrospinal fluid might be sampled in this manner possibly eliminating or reducing the headaches often encountered with spinal taps. Given the extremely small volumes within the microworms simple diffusion could transport the chemicals of interest quickly to the transduction unit. Interstitial fluid concentrations might also be a target for this type of sampling.
There are added risks involved in any of these concepts. The appropriate risk analysis and mitigation exercises would have to be executed but under the right conditions the concepts could prove useful new tools.