Green Microneedle Technologies for the Management of Neurodegenerative Diseases: From Conceptual Promise to Translational Challenges

ABSTRACT:Microneedles offer a less invasive way of delivering medications transdermally,mixing low pain delivery with the convenience of not having to take a pill or get an injection.The potential to offer patients the ability to administer their own medicine is a large selling pointfor this type of technology, especially for patients with chronic illnesses. Bio-degradablepolymer microneedles offer the prospect of being a sustainable alternative to conventionalmicroneedles. Sustained microneedle delivery systems are particularly relevant for themanagement of chronic illnesses like Alzheimer’s, Parkison’s, and ALS due to the need forfrequent and precise dosing. It should be noted, however, that while the body of research israpidly expanding, the translational research for green microneedles has been severely lacking.The primary focus of this analysis is the selection of polysaccharide bio materials, including theirdesign, production technology and methodologies, and the loading of bioactive molecules intomicroneedles for the focused application pertaining to sustained microneedle delivery systemsfor the treatment of neurodegenerative disorders. Providing a counterpoint to most of thereviewed literature, this analysis draws attention to the limitations of the technology with specificfocus on marginal mechanical strength and polysaccharide bio materials. Polysaccharide biomaterials, particularly naturally occurring biopolymers, typically display a significant batch tobatch variability. The analysis suggests that the prevailing methodologies to isolate biopolymers,especially for bio-pharmaceutical applications, has not matured or been validated to anacceptable commercial scale, have provided only marginal or temporary solutions to theinefficiencies of the existing processes, particularly in the treatment of chronic illnesses.Thisreview suggests that while green microneedles do have therapeutic and environmental potential,for them to be successfully deployed clinically, they would need to show less proof-of-conceptand more manufacturing standardization, regulation, and safety follow up studies.