Browsing by Author "Biomedical Engineering, Purdue School of Engineering and Technology"

Now showing 1 - 6 of 6
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    Feeding the Kidney Researcher Pipeline through R25-NIDDK Funded Summer Undergraduate Research Fellowships: A Student Perspective
    (Wolters Kluwer, 2022-03-31) Wilson, Elena M.; Lipp, Sarah N.; Brady, Clayton T.; Ishibe, Shuta; Romero, Michael F.; Biomedical Engineering, Purdue School of Engineering and Technology
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    Geometric Characterization of Local Changes in Tungsten Microneedle Tips after In-Vivo Insertion into Peripheral Nerves
    (MDPI, 2022) Sergi, Pier Nicola; Jensen, Winnie; Yoshida, Ken; Biomedical Engineering, Purdue School of Engineering and Technology
    Peripheral neural interfaces are used to connect the peripheral nervous system to high-tech robotic devices and computer interfaces. Soft materials are nowadays used to build the main structural part of these interfaces because they are able to mimic the mechanical properties of peripheral nerves. However, if on the one hand soft materials provide effective connections, reducing mechanical mismatch with nervous tissues and creating a close contact between active sites and neural fibers, on the other hand, most of them are not mechanically stable during implantation. As a consequence, tungsten (W) microneedles are used to insert soft neural interfaces, because they are able to pierce the peripheral nervous tissue because of their high stiffness. Nevertheless, this stiffness cannot prevent microneedles from local microscopic structural damage, even after successful insertions. In addition, the nature of this damage is not totally clear. Therefore, this work aimed at quantitatively investigating the phenomenological changes of the microneedles’ tip shape after insertion into the in vivo peripheral nerves. In particular, a quantification of the interactions between peripheral nerves and W microneedles was proposed through the Oliver-Pharr formula, and the interaction force was found to be directly proportional to the power < m > = 2.124 of the normalized indentation depth. Moreover, an experimental correlation between insertion force and the opening tip angle was described together with an assessment of the minimum diameter to effectively puncture the peripheral nervous tissue. Finally, a computational framework was presented to describe the local changes affecting the microneedles’ tip shape. This approach was able to detect a bulging phenomenon along with the microneedle tips with a characteristic amplitude of approximately 100 μm, and a folding phenomenon, with a characteristic mean amplitude of less than 20 μm, affecting the extreme ending sections of the microneedle tips. These geometrical changes were related to the synergistic action of interaction forces likely resulting in compression and elastic instability of the tip.
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    Mechanical Loading Mitigates Osteoarthritis Symptoms by Regulating the Inflammatory Microenvironment
    (SSRN, 2021-06-14) Zhang, Weiwei; Li, Xinle; Li, Jie; Wang, Xiaoyu; Liu, Daquan; Zhai, Lidong; Ding, Beibei; Li, Guang; Sun, Yuting; Yokota, Hiroki; Zhang, Ping; Biomedical Engineering, Purdue School of Engineering and Technology
    Osteoarthritis (OA) is one of the most common chronic diseases, in which inflammatory responses in the articular cavity induce chondrocyte apoptosis and cartilage degeneration. While mechanical loading is reported to mitigate synovial inflammation, the mechanism and pathways for the loading-driven improvement of OA symptoms remain unclear. In this research, we evaluated the loading effects on the M1/M2 polarization of synovial macrophages via performing molecular, cytology, and histology analyses. In the OA groups, the cell layer of the synovial lining was enlarged with an increase in cell density. Also, M1 macrophages were polarized and pro-inflammatory cytokines were increased. In contrast, in the OA group with mechanical loading cartilage degradation was reduced and synovial inflammation was alleviated. Notably, the polarization of M1 macrophages was diminished by mechanical loading, while that of M2 macrophages was increased. Furthermore, mechanical loading decreased the levels of pro-inflammatory cytokines such as IL-1β and TNF-α and suppressed PI3K/AKT/NF-κB signaling. Consistently, NF-κB inhibited decreased the polarization of M1 macrophages in RAW264.7 macrophages. Taken together, this study demonstrates that mechanical loading changes the ratio of M1 and M2 macrophage polarization via regulating PI3K/AKT/NF-κB signaling and provides chondroprotective effects in the mouse OA model.
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    Progerin-Induced Impairment in Wound Healing and Proliferation in Vascular Endothelial Cells
    (Frontiers Media, 2022-03-14) Jiang, Yizhi; Ji, Julie Y.; Biomedical Engineering, Purdue School of Engineering and Technology
    Progerin as a mutated isoform of lamin A protein was first known to induce premature atherosclerosis progression in patients with Hutchinson-Gilford progeria syndrome (HGPS), and its role in provoking an inflammatory response in vascular cells and accelerating cell senescence has been investigated recently. However, how progerin triggers endothelial dysfunction that often occurs at the early stage of atherosclerosis in a mechanical environment has not been studied intensively. Here, we generated a stable endothelial cell line that expressed progerin and examined its effects on endothelial wound repair under laminar flow. We found decreased wound healing rate in progerin-expressing ECs under higher shear stress compared with those under low shear. Furthermore, the decreased wound recovery could be due to reduced number of cells at late mitosis, suggesting potential interference by progerin with endothelial proliferation. These findings provided insights into how progerin affects endothelial mechanotransduction and may contribute to the disruption of endothelial integrity in HGPS vasculature, as we continue to examine the mechanistic effect of progerin in shear-induced endothelial functions.
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    Triple click chemistry for crosslinking, stiffening, and annealing of gelatin-based microgels
    (Royal Society of Chemistry, 2024-03-28) Chang, Chun-Yi; Nguyen, Han; Frahm, Ellen; Kolaczyk, Keith; Lin, Chien-Chi; Biomedical Engineering, Purdue School of Engineering and Technology
    Microgels are spherical hydrogels with physicochemical properties ideal for many biomedical applications. For example, microgels can be used as individual carriers for suspension cell culture or jammed/annealed into granular hydrogels with micron-scale pores highly permissive to molecular transport and cell proliferation/migration. Conventionally, laborious optimization processes are often needed to create microgels with different moduli, sizes, and compositions. This work presents a new microgel and granular hydrogel preparation workflow using gelatin-norbornene-carbohydrazide (GelNB-CH). As a gelatin-derived macromer, GelNB-CH presents cell adhesive and degradable motifs while being amenable to three orthogonal click chemistries, namely the thiol-norbornene photo-click reaction, hydrazone bonding, and the inverse electron demand Diels-Alder (iEDDA) click reaction. The thiol-norbornene photo-click reaction (with thiol-bearing crosslinkers) and hydrazone bonding (with aldehyde-bearing crosslinkers) were used to crosslink the microgels and to realize on-demand microgel stiffening, respectively. The tetrazine-norbornene iEDDA click reaction (with tetrazine-bearing crosslinkers) was used to anneal microgels into granular hydrogels. In addition to materials development, we demonstrated the value of the triple-click chemistry granular hydrogels via culturing human mesenchymal stem cells and pancreatic cancer cells.
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    Unveiling the Dichotomy of Urinary Proteins: Diagnostic Insights into Breast and Prostate Cancer and Their Roles
    (MDPI, 2023-12-26) Feng, Yan; Huo, Qingji; Li, Bai-Yan; Yokota, Hiroki; Biomedical Engineering, Purdue School of Engineering and Technology
    This review covers the diagnostic potential of urinary biomarkers, shedding light on their linkage to cancer progression. Urinary biomarkers offer non-invasive avenues for detecting cancers, potentially bypassing the invasiveness of biopsies. The investigation focuses primarily on breast and prostate cancers due to their prevalence among women and men, respectively. The intricate interplay of urinary proteins is explored, revealing a landscape where proteins exhibit context-dependent behaviors. The review highlights the potential impact of physical activity on urinary proteins, suggesting its influence on tumorigenic behaviors. Exercise-conditioned urine may emerge as a potential diagnostic biomarker source. Furthermore, treatment effects, notably after lumpectomy and prostatectomy, induce shifts in the urinary proteome, indicating therapeutic impacts rather than activating oncogenic signaling. The review suggests further investigations into the double-sided, context-dependent nature of urinary proteins, the potential role of post-translational modifications (PTM), and the integration of non-protein markers like mRNA and metabolites. It also discusses a linkage of urinary proteomes with secretomes from induced tumor-suppressing cells (iTSCs). Despite challenges like cancer heterogeneity and sample variability due to age, diet, and comorbidities, harnessing urinary proteins and proteoforms may hold promise for advancing our understanding of cancer progressions, as well as the diagnostic and therapeutic role of urinary proteins.