No abstract

Microneedles have recently been adopted for use as a painless and safe method of transdermal therapeutic delivery through physically permeating the stratum corneum. While microneedles create pathways to introduce drugs, they can also act as conduits for biosignal sensing. Here, we explore the development of microneedles as both biosensing and drug delivery platforms. Microneedle sensors are being developed for continuous monitoring of biopotentials and bioanalytes through the use of conductive and electrochemically reactive biomaterials. The range of therapeutics being delivered through microneedle devices has diversified, while novel bioabsorbable microneedles are undergoing first-in-human clinical studies. We foresee that future microneedle platform development will focus on the incorporation of biofunctional materials, designed to deliver therapeutics in a stimulus responsive fashion. Biofunctional microneedle patches will require improved methods of attaching to and conforming to epithelial tissues in dynamic environments for longer periods of time and thus present an assortment of new design challenges. Through the evolution of biomaterial development and microneedle design, biofunctional microneedles are proposed as a next generation of stimulus responsive drug delivery systems.

electrode in combination with conductive gel. The conductive gel typically has three purposes. [2] It should allow for some movement of the electrode without loss of skin contact, diffuse into the skin, keep it wet, and thereby enhance its conductivity. While hair ideally should be removed, gel may also ensure electrode skin contact in the presence of hair by surrounding it. Overcoming the impedance posed by skin, especially the outermost layer of the epidermis, the stratum corneum, is an inherent issue with noninvasive biopotential recording techniques. Skin impedance reduction methods may involve washing of the skin, application of an abrasive conductive gel, skin shaving, stratum corneum removal by means of tape stripping, as well as the use of penetration enhancers. [2] Skin preparation steps are tedious, timeconsuming, unpleasant to the user or patient, and may even result in adverse skin reactions or infection. [3,4] While skin preparation is considered best practice and likely to continue to be used in research and clinical settings where acquisition of the highest quality data possible is necessary, there are settings where avoidance of skin preparation is desired, if not required. Such settings may include the clinic where time equates cost or signal acquisition by nonexpert users. Even with skin preparation applied, recording may be restricted in time due to drying of the wet gel interface associated with loss in skin contact quality. [1,4,5] This makes conventional wet electrodes unsuitable for long-term applications such as myoelectrically controlled prosthetics or robotic interfaces. To facilitate the widespread translation of sEMG to the clinic and applications involving long-term recording, new types of electrodes are thus required which allow for ease of application (e.g., no need for skin preparation; wet gel electrodes generally are not repositionable), display reduced contact impedance (e.g., overcome the high impedance stratum corneum), and provide consistency during long-term recording as well as delivering repeatable results. One approach to decrease contact impedance is to increase the overall electrode surface area by adding microstructures. Researchers have fabricated microstructured electrodes by mixing a polymer with a conductive filler (carbon nanotubes, acetylene black, carbon black, graphite, or silver). [6-8] Another approach is to first produce Surface electromyography (sEMG) allows for direct measurement of electrical muscle activity with use in fundamental research and many applications in health and sport. However, conventional surface electrode technology can suffer from poor signal quality, requires careful skin preparation, and is commonly not suited for long-term recording. These drawbacks have challenged translation of sEMG to clinical applications. In this paper, dry 3D-printed microneedle electrodes (MNEs) are proposed to overcome some of the limitations of conventional electrodes. Employing a direct-metallaser-sintering (DMLS) 3D printing process, a two-step fabrication ...

No abstract

Introduction Evidence-based medicine (EBM) refers to medical practice that uses current best evidence to inform decision-making. This requires several skills including (1) creating an answerable question, (2) searching literature, (3) critically appraising evidence, and (4) applying results. Journal clubs are known to be effective in improving searching and critical appraisal skills in graduate medical education. In pre-clerkship medical education, journal clubs are used less often, and students often do not have the opportunity to engage in all of the steps above. Methods We developed a journal club for pre-clerkship students and measured its effectiveness using a pre-test, post-test design. Students attended 5 journal club sessions run by rotating student leaders and facilitated by faculty. Student groups developed searchable questions from clinical cases, searched the literature, located and critically appraised an article, and applied results to the case. We measured EBM skills and confidence using two validated questionnaires. Results Twenty-nine students (MS-1 and MS-2) completed the study. EBM confidence significantly improved at post-test with greatest improvements in the MS-1 student cohort. Confidence in developing a searchable question from a patient case significantly improved in both cohorts. There were no changes measured on the Test of EBM Knowledge and Skills. Discussion Participation in a faculty-mentored, student-led journal club improved confidence across all domains of EBM, primarily in MS-1 students. Journal clubs are positively received by pre-clerkship medical students and provide effective mechanisms to teach and promote all steps of EBM in pre-clerkship curricula. Supplementary Information The online version contains supplementary material available at 10.1007/s40670-023-01779-y.