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Lipid rafts are highly ordered regions of the plasma membrane enriched in signaling proteins and lipids. Their biological potential is realized in exosomes, a subclass of extracellular vesicles (EVs) that originate from the lipid raft domains. Previous studies have shown that EVs derived from human placental mesenchymal stromal cells (PMSCs) possess strong neuroprotective and angiogenic properties. However, clinical translation of EVs is challenged by very low, impure, and heterogeneous yields. Therefore, in this study, lipid rafts are validated as a functional biomaterial that can recapitulate the exosomal membrane and then be synthesized into biomimetic nanovesicles. Lipidomic and proteomic analyses show that lipid raft isolates retain functional lipids and proteins comparable to PMSC-EV membranes. PMSC-derived lipid raft nanovesicles (LRNVs) are then synthesized at high yields using a facile, extrusion-based methodology. Evaluation of biological properties reveals that LRNVs can promote neurogenesis and angiogenesis through modulation of lipid raft-dependent signaling pathways. A proof-of-concept methodology further shows that LRNVs could be loaded with proteins or other bioactive cargo for greater disease-specific functionalities, thus presenting a novel type of biomimetic nanovesicles that can be leveraged as targeted therapeutics for regenerative medicine.

Metacognitive skills can have enormous benefits for students within engineering courses. Unfortunately, these metacognitive skills tend to fall outside the content area of most courses, and consequently, they can often be neglected in instruction. In this context, previous research on concept mapping as a teaching strategy points to meaningful learning. The purpose of this innovation paper is to report an application of concept mapping (1) to facilitate metacognition steps in students, and (2) to identify the muddiest points students struggle with, during both in-person and online instruction of a problem-solving-based biomedical engineering course. This innovation article also looks at the usefulness of concept mapping through instructor and student perceptions and students’ class performance. The entire concept mapping intervention was conducted during weeks 8–10 of the Spring 2019 in-person quarter and during weeks 3–4 and 8–10 of the Spring 2021 online quarter. The exercise involved concept mapping, explanation and discussion with peers, and answering structured reflection prompts. Each concept map activity was contextualized to the metacognitive knowledge domain of the revised Bloom’s taxonomy. The average class performance was compared between students who completed concept mapping vs. those who did not, using a t-test and one-way ANOVA at alpha = 0.05 significance level followed by a Tukey HSD test. Students’ concept maps and reported answers were analyzed qualitatively following the concept mapping intervention. During the Spring 2019 in-person quarter, 59.30% of students completed concept mapping with reflection, whereas 47.67% completed it in spring 2021 online instruction. A two-tailed, unpaired t-test indicated that concept mapping did not significantly enhance students’ class performance (p> 0.05) within each of the in-person and online instructions. Peers’ suggestions to students to improve concept maps revealed themes related to course concepts, prerequisite concepts, and the act of concept mapping itself. Concept mapping was effective in revealing the muddiest points of the course. Concept mapping did not significantly enhance students’ class performance either in-person or online instruction (effect sizes were 0.29 for the 2019 in-person quarter and 0.33 for the 2021 online quarter). However, instructors and students’ perceptions reflected that concept mapping facilitated metacognition in a problem-solving-based biomedical engineering course both during in-person and online instruction. Most students (78%) were optimistic about the usefulness of concept mapping for this course, and 84% were inclined to apply it for a variety of other courses.