Extracellular Matrix Secretion Mechanically Reinforces Interlocking Interfaces.

Drawing inspiration for biomaterials from biological systems has led to many biomedical innovations. One notable bioinspired device, Velcro, consists of two substrates with interlocking ability. Generating reversibly interlocking biomaterials is an area of investigation, as such devices can allow for modular tissue engineering, reversibly interlocking biomaterial interfaces, or friction-based coupling devices. Here, a biaxially interlocking interface generated using electrostatic flocking is reported. Two electrostatically flocked substrates are mechanically and reversibly interlocked with the ability to resist shearing and compression forces. An initial high-throughput screen of polyamide flock fibers with varying diameters and fiber lengths is conducted to elucidate the roles of different fiber parameters on scaffold mechanical properties. After determining the most desirable parameters via weight scoring, polylactic acid (PLA) fibers are used to emulate the ideal scaffold for in vitro use. PLA flocked scaffolds are populated with osteoblasts and interlocked. Interlocked flocked scaffolds improved cell survivorship under mechanical compression and sustained cell viability and proliferation. Additionally, the compression and shearing resistance of cell-seeded interlocking interfaces increased with increasing extracellular matrix deposition. The introduction of extracellular matrix-reinforced interlocking interfaces may serve as binders for modular tissue engineering, act as scaffolds for engineering tissue interfaces, or enable friction-based couplers for biomedical applications.

Electrostatic flocking of salt-treated microfibers and nanofiber yarns for regenerative engineering.

Electrostatic flocking is a textile technology that employs a Coulombic driving force to launch short fibers from a charging source towards an adhesive-covered substrate, resulting in a dense array of aligned fibers perpendicular to the substrate. However, electrostatic flocking of insulative polymeric fibers remains a challenge due to their insufficient charge accumulation. We report a facile method to flock electrostatically insulative poly(ε-caprolactone) (PCL) microfibers (MFs) and electrospun PCL nanofiber yarns (NFYs) by incorporating NaCl during pre-flock processing. Both MF and NFY were evaluated for flock functionality, mechanical properties, and biological responses. To demonstrate this platform's diverse applications, standalone flocked NFY and MF scaffolds were synthesized and evaluated as scaffold for cell growth. Employing the same methodology, scaffolds made from poly(glycolide-co-l-lactide) (PGLA) (90:10) MFs were evaluated for their wound healing capacity in a diabetic mouse model. Further, a flock-reinforced polydimethylsiloxane (PDMS) disc was fabricated to create an anisotropic artificial vertebral disc (AVD) replacement potentially used as a treatment for lumbar degenerative disc disease. Overall, a salt-based flocking method is described with MFs and NFYs, with wound healing and AVD repair applications presented.

Social Data: An Underutilized Metric for Determining Participation in COVID-19 Vaccinations.

Many measures have been taken since late 2019 to combat the coronavirus disease (COVID-19) pandemic. National, state, and local governments employed precautions, including mask mandates, stay-at-home orders, and social distancing policies, to alleviate the burden on healthcare workers and slow the spread of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) virus until an efficacious vaccine was made widely available. By early spring of 2021, three effective and well-tolerated SARS-CoV-2 vaccines emerged and underwent broad distribution. Throughout the course of the COVID-19 vaccination campaign, several key logistical and psychological issues surfaced. Of these, access to vaccines and vaccination hesitancy are cited as two substantial hindrances towards vaccination. Noting the demand for the SARS-CoV-2 vaccine and its highly sensitive storage requirements, accurate dose allocation is critical for vaccinating the population quickly and successfully. Here, we propose the use of social data as a tool to predict vaccination participation by correlating Google searches with state-level daily vaccination. We identified a temporal and regionally-ubiquitous Google search syntax that broadly captures daily vaccination trends. By correlating trends in the search syntax with daily vaccination rates, we were able to quantify the correlation and identify optimal lag periods between Google searches and daily vaccination. This work highlights the importance of analyzing social data as a metric to effectively arrange vaccination roll-outs, identify voluntary vaccination participation, and identify inflection points in vaccination participation. In addition, social data assessments can help direct dose allocation, identify geographic areas that may seek, but lack, access to the vaccines, and actively prepare for fluctuations in vaccination demands.