Over the past decade, vital advances within the biomanufacturing of microneedle-based gadgets (MN)s have emerged highlighting their potential over a spread of therapeutic purposes. Nevertheless, making certain that these MNs penetrate simply the fitting depth to work successfully with out inflicting hurt has been a persistent problem. Researchers at the moment are tackling this challenge, paving the best way for extra exact and safer remedies. A brand new method to controlling the penetration depth of an array of hole MNs have been efficiently developed by a crew led by Dr. Maryam Mobed-Miremadi of Santa Clara College, CA, USA. Incorporation of a stopper above the tip restricted penetration to a goal depth of 150 µm, making certain precision inside the epidermal layer. This work, revealed within the journal of Utilized Mechanics, makes use of a stopper mechanism to make sure exact concentrating on whereas sustaining structural integrity of the 3D-printed system beneath mechanical load.
MNs have been fabricated utilizing stereolithography (SLA), leveraging a biocompatible photoresin with a 25–50 µm decision. Shrinkage was quantitatively assessed post-curing utilizing transmission microscopy and imaging analyses. Skinny sterilized cross-linked alginate hydrogel slabs have been used as pores and skin analogs to imitate the biomechanical properties of the dermis. Mechanical testing on these biocompatible hydrogels confirmed the MNs potential to attain uniform penetration. Profilometry analyses additional validated the efficacy of the stopper in sustaining constant depth throughout varied checks. Pycnometry was used to measure the density of hydrogel movies earlier than and after puncture to verify mass redistribution versus materials loss throughout microneedle indentation.
Intensive testing of the hydrogel phantoms revealed the MNs potential to resist forces exceeding these usually required for epidermal penetration. Measurements of peak puncture forces, hardness and viscoelastic properties be sure that the design met the required requirements for sensible purposes. The stopper’s function in enhancing uniformity and decreasing variability in puncture was a big discovering.
Simulations utilizing COMSOL software program have been performed to mannequin stress distributions and deformation throughout system insertion with the experimentally-determined properties of the phantoms and shrinkage parameters. Density findings weren’t immediately simulated however have been knowledgeable materials property inputs for the computational mannequin. These in silico experiments complemented the empirical outcomes, offering insights into the mechanical efficiency and areas for potential design optimization. Stress rest profiles and insertion power traits carefully aligned with experimental outcomes reinforcing the robustness of the design and built-in course of for system testing.
This research’s methodology and findings present a basis for advancing MN expertise in precision medical purposes. The researchers goal to refine the method for nozzle-to-nozzle penetration reproducibility and scalability. Design flexibility enabled by adapting the stopper’s dimension to insertion depth initially supposed for microencapsulated cell supply expands the potential use to purposes equivalent to transdermal drug supply and biomarker detection, minimizing discomfort and maximizing therapeutic outcomes.
Journal Reference
Defelippi, Okay.M.; Kwong, A.Y.S.; Appleget, J.R.; Altay, R.; Matheny, M.B.; Dubus, M.M.; Eribes, L.M.; Mobed-Miremadi, M. “An Built-in Strategy to Management the Penetration Depth of 3D-Printed Hole Microneedles.” Appl. Mech.2024, 5, 233-259. https://doi.org/10.3390/applmech5020015
Concerning the Authors
Celebrating 100 years of Girls in Engineering the authors biographies are:

Dr. Maryam Mobed-Miremadi is a Educating Professor within the Division of Bioengineering at Santa Clara College. Her present analysis pursuits embody simulation, optimization, and statistical validation throughout multiscale biomaterials-related platforms, together with sustainable vitality purposes.

Kendall DeFelippi graduated from Santa Clara College in December 2023 with an MS in Bioengineering. Along with engaged on medical purposes of microneedles (MNs), she has researched microneedle scaling for bioprocessing purposes. Kendall at present works as an Affiliate Scientist at Neurocrine Biosciences in San Diego, CA.

Allyson Kwong is a bioengineering pupil pursuing a five-year BS/MS diploma at Santa Clara College and dealing as a part-time engineer at Stryker Medical. She continues to analysis quantitative puncture characterization in mushy supplies.

Julia Appleget is an Electrical Engineering pupil pursuing an MS diploma at Santa Clara College. As a recipient of the Clare Boothe undergraduate grant, her analysis in bioengineering centered on leveraging the mechanical and electrical properties of tetrafunctional hydrogel networks in biomedical system and bioenergy purposes.

Rana Altay is a PhD pupil in Dr. Araci’s lab at Santa Clara College. Her analysis lies on the intersection of microfluidics and wearable applied sciences. Previous to attending Santa Clara College, she studied Mechatronics Engineering at Sabancı College in Turkey.

Maya Matheny is a first-year MD candidate on the Keck Faculty of Medication on the College of Southern California. She earned her bachelor’s diploma in Bioengineering from Santa Clara College, the place she developed an curiosity in biofabrication. Maya is captivated with advancing healthcare fairness and mixing technical experience with compassionate affected person care.

Maggie Dubus is a first-year MD pupil on the College of Colorado Faculty of Medication. She earned her bachelor’s diploma in Bioengineering from Santa Clara College, the place she developed her translational analysis abilities. Maggie is dedicated to integrating translational analysis with high-quality, compassionate affected person care all through her medical profession.

Lily Eribes works as an engineer for Microchip Know-how Inc. in Arizona. She earned her bachelor’s diploma in Bioengineering from Santa Clara College, the place she served as a Healthcare Innovation Fellow and researcher.

