Enhanced transcription and translation in clay hydrogel and implications for early life evolution

In most contemporary life forms, the confinement of cell membranes provides localized concentration and protection for biomolecules, leading to efficient biochemical reactions. Similarly, confinement may have also played an important role for prebiotic compartmentalization in early life evolution when the cell membrane had not yet formed. It remains an open question how biochemical reactions developed without the confinement of cell membranes. Here we mimic the confinement function of cells by creating a hydrogel made from geological clay minerals, which provides an efficient confinement environment for biomolecules. We also show that nucleic acids were concentrated in the clay hydrogel and were protected against nuclease, and that transcription and translation reactions were consistently enhanced. Taken together, our results support the importance of localized concentration and protection of biomolecules in early life evolution, and also implicate a clay hydrogel environment for biochemical reactions during early life evolution

Using a 2-Stage Strategy with Respondent-Driven Sampling to Recruit a Hard-to-Reach Population for a Placebo Microbicide Gel Clinical Trial in Nellore, Andhra Pradesh (India)

Traditional recruitment methods for microbicide efficacy trials are labor intensive and may fail to reach high-risk hard-to-reach populations. We report duration of recruitment and lessons learned from a two-stage process to recruit female sex workers (FSWs) into a placebo microbicide trial, and examined characteristics associated with successful recruitment of peers who screened for and enrolled in the trial. FSWs were first recruited via respondent-driven sampling (RDS) to complete a survey and subsequently invited to screen for enrollment into a placebo microbicide trial taking place at a local clinic. It took 6 months to enroll 267 participants into the trial. Successful recruiters of peers who enrolled were more likely to have enrolled themselves (AOR 2.0, CI 1.3–2.9) and less likely to visit Nellore city (AOR 0.5, CI 0.3–0.9). Recruitment of FSWs via a two-stage recruitment strategy with RDS can be a good option for future clinical trials