Going Viral: Assessing the Impact of Social Media on Enrollment in a Coronavirus Disease 2019 (COVID-19) Cohort Study.

Objective This study aimed to quantify the effect of social media posts on study enrollment among children with mild coronavirus disease 2019 (COVID-19). Methods The primary outcome was weekly study enrollments analyzed using a run chart. A secondary analysis used linear regression to assess study enrollments two days before and after a social media post, adjusted for the statewide pediatric seven-day-average severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) case rate, social media posting day, and the interaction of these two variables. Results In seven months before social media posting, only eight patients were enrolled. One week after social media posting began, the median weekly enrollment increased (0 to 3). In the regression model, neither social media post day nor the pediatric SARS-CoV-2 case rate was significantly associated with enrollment rate. However, the interaction of a post day and the pediatric case rate was significant. Conclusion Social media posts significantly increased enrollment among children with mild COVID-19 in a prospective study. This effect was amplified by the presence of high community case rates during the Omicron wave.

Scaffoldless tissue-engineered nerve conduit promotes peripheral nerve regeneration and functional recovery after tibial nerve injury in rats.

Damage to peripheral nerve tissue may cause loss of function in both the nerve and the targeted muscles it innervates. This study compared the repair capability of engineered nerve conduit (ENC), engineered fibroblast conduit (EFC), and autograft in a 10-mm tibial nerve gap. ENCs were fabricated utilizing primary fibroblasts and the nerve cells of rats on embryonic day 15 (E15). EFCs were fabricated utilizing primary fibroblasts only. Following a 12-week recovery, nerve repair was assessed by measuring contractile properties in the medial gastrocnemius muscle, distal motor nerve conduction velocity in the lateral gastrocnemius, and histology of muscle and nerve. The autografts, ENCs and EFCs reestablished 96%, 87% and 84% of native distal motor nerve conduction velocity in the lateral gastrocnemius, 100%, 44% and 44% of native specific force of medical gastrocnemius, and 63%, 61% and 67% of native medial gastrocnemius mass, respectively. Histology of the repaired nerve revealed large axons in the autograft, larger but fewer axons in the ENC repair, and many smaller axons in the EFC repair. Muscle histology revealed similar muscle fiber cross-sectional areas among autograft, ENC and EFC repairs. In conclusion, both ENCs and EFCs promoted nerve regeneration in a 10-mm tibial nerve gap repair, suggesting that the E15 rat nerve cells may not be necessary for nerve regeneration, and EFC alone can suffice for peripheral nerve injury repair.

Development of a scaffoldless three-dimensional engineered nerve using a nerve-fibroblast co-culture.

Nerve grafts are often required to replace tissue damaged by disease, surgery, or extensive trauma. Limitations such as graft availability, donor site morbidity, and immune rejection have led investigators to develop strategies to engineer nerve tissue. The goal of this study was to fabricate a scaffoldless three-dimensional (3D) nerve construct using a co-culture of fetal nerve cells with a fibroblast monolayer and allow the co-culture to remodel into a 3D construct with an external fibroblast layer and an internal core of interconnected neuronal cells. Primary fibroblasts were seeded on laminin-coated plates and allowed to form a confluent monolayer. Neural cells isolated from E-15 spinal cords were seeded on top of the fibroblast monolayer and allowed to form a networked monolayer across the monolayer of fibroblasts. Media shifts initiated contraction of the fibroblast monolayer and a remodeling of the co-culture into a 3D construct held statically in place by the two constraint pins. Immunohistochemistry using S100 (Schwann cell), beta3-tubulin, DAPI, and collagen I indicated an inner core of nerve cells surrounded by an external layer of fibroblasts. Conduction velocities of the 3D nerve and control (fibroblast-only) constructs were measured in vitro and compared to in vivo measures of neonatal sciatic nerve. The conduction velocities of the nerve constructs were comparable to 24-d-old neonatal nerve. The presence of Schwann cells and the ability to conduct neuronal signals in vitro suggest the scaffoldless 3D nerve constructs will be a viable option for nerve repair.