ABSTRACT
Here, we describe strategies for integrating transferrable professional development (PD) skills into research learning environments for marginalized undergraduate students. The undergraduate research experience evolved to include the competencies students need to be successful and to gain a sense of belonging in the chemistry community they are seeking. These asset-based transferrable PD skills are part of the "hidden curriculum" not taught in traditional classrooms and yet are an integral part of student learning and success. Furthermore, current practices, or lack thereof, tend to promote inequity and fail to amplify key asset-based skills for marginalized students to navigate academic, industrial, and professional settings effectively. Consequently, many students leave STEM communities. The following six PD skills are core competencies that have been implemented in a diverse undergraduate research environment to equip students with the skills needed to navigate various STEM environments. These include: (1) Effective Communication, (2) Negotiation, (3) Leadership, (4) Networking, (5) Interpersonal skills, and (6) Active Listening. Learning topics for each of the PD skills enable mentors to help preprofessional, marginalized students gain a sense of belonging, build a network, connect with mentors, develop self-advocacy, implement interpersonal skills, manage conflict, and navigate spaces that do not fully represent them. The inclusive integration of scientific and PD skills into research experiences serves as a template that can be extended to high school and graduate students. These integrated transferrable skills are one way to increase diversity in STEM professions and bridge the gap in leadership in academia and industry.
ABSTRACT
The controlled synthesis of stable silver nanoparticles (AgNPs), that do not undergo surface oxidation and Ag+ ion dissolution, continues to be a major challenge. Here the synthesis of robust hybrid lipid-coated AgNPs, comprised of l-α-phosphatidylcholine (PC) membranes anchored by a stoichiometric amount of long-chained hydrophobic thiols and sodium oleate (SOA) as hydrophobic binding partners, that do not undergo surface oxidation and Ag+ ion dissolution, is described. UV-Visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometry (ICP-MS) demonstrate that in the presence of strong oxidants, such as potassium cyanide (KCN), the hybrid lipid-coated AgNPs are stable and do not undergo surface oxidation even in the presence of membrane destabilizing surfactants. UV-Vis studies show that the stability of hybrid lipid-coated AgNPs of various sizes and shapes is dependent on the length of the thiol hydrocarbon chain and can be ranked in the order of increasing stability as follows: propanethiol (PT) < hexanethiol (HT) ≤ decanethiol (DT). UV-Vis and ICP-MS studies show that the hybrid lipid-coated AgNPs do not change in size or shape confirming that the AgNPs do not undergo surface oxidation and Ag+ ion dissolution when placed in the presence of strong oxidants, chlorides, thiols, and low pH. Long-term stability studies, over 21 days, show that the hybrid lipid-coated AgNPs do not release Ag+ ions and are more stable. Overall, these studies demonstrate hybrid membrane encapsulation of nanomaterials is a viable method for stabilizing AgNPs in a "shape-locked" form that is unable to undergo surface oxidation, Ag+ ion release, aging, or shape conversion. More importantly, this design strategy is a simple approach to the synthesis and stabilization of AgNPs for a variety of biomedical and commercial applications where Ag+ ion release and toxicity is a concern. With robust and shielded AgNPs, investigators can now evaluate and correlate how the physical features of AgNPs influence toxicity without the confounding factor of Ag+ ions present in samples. This design strategy also provides an opportunity where the membrane composition can be tuned to control the release rate of Ag+ ions for optimizing antimicrobial activity.
