Revolving hexameric ATPases as asymmetric motors to translocate double-stranded DNA genome along one strand.

DsDNA translocation through nanoscale pores is generally accomplished by ATPase biomotors. The discovery of the revolving dsDNA translocation mechanism, as opposed to rotation, in bacteriophage phi29 elucidated how ATPase motors move dsDNA. Revolution-driven, hexameric dsDNA motors have been reported in herpesvirus, bacterial FtsK, Streptomyces TraB, and T7 phage. This review explores the common relationship between their structure and mechanisms. Commonalities include moving along the 5'→3' strand, inchworm sequential action leading to an asymmetrical structure, channel chirality, channel size, and 3-step channel gating for controlling motion direction. The revolving mechanism and contact with one of the dsDNA strands addresses the historic controversy of dsDNA packaging using nicked, gapped, hybrid, or chemically modified DNA. These controversies surrounding dsDNA packaging activity using modified materials can be answered by whether the modification was introduced into the 3'→5' or 5'→3' strand. Perspectives concerning solutions to the controversy of motor structure and stoichiometry are also discussed.

Advances in engineering and delivery strategies for cytokine immunotherapy.

INTRODUCTION: Cytokine immunotherapy is a growing field for the treatment of cancer, infectious disease, autoimmunity, and other ailments. Therapeutic cytokines are a class of secreted, small proteins that play a pivotal role in regulating the innate and adaptive immune system by provoking or mitigating immune responses. In the clinic, cytokines are frequently combined with other treatments, such as small molecules and monoclonal antibodies. However, the clinical translation of cytokine therapies is hindered by their short half-life, pleiotropic nature, and off-target effects, which cause diminished efficacy and severe systemic toxicity. Such toxicity limits dosage, thus resulting in suboptimal doses. Accordingly, numerous efforts have been devoted to exploring strategies to promote cytokine therapies by improving their tissue specificity and pharmacokinetics. AREAS COVERED: Preclinical and clinical research into bioengineering and delivery strategies for cytokines, consisting of bioconjugation, fusion proteins, nanoparticles, and scaffold-based systems. EXPERT OPINION: These approaches pave the way for the development of next-generation cytokine treatments with greater clinical benefit and reduced toxicity, circumventing such issues currently associated with cytokine therapy.

Advances of nanomaterials-based strategies for fighting against COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected over 100 million people globally due to its high infectivity. After decades of efforts on the studies of nanomaterials, researchers have applied nanomaterials-based strategies to combat the pandemic of the coronavirus disease 2019 (COVID-19). First, nanomaterials facilitate the development of easy, fast, and low-cost diagnostic assays to detect SARS-CoV-2 and related biomarkers. Second, nanomaterials enable the efficient delivery of viral antigens to antigen-presenting cells or serve as adjuvants in the host, leading to vaccine development at an unprecedented pace. Lastly, nanomaterials-based treatments may inhibit SARS-CoV-2 replication and reduce inflammation. Overall, nanomaterials have played important roles in controlling this COVID-19 pandemic. Here, we provide a brief overview of the representative examples of nanomaterials-based diagnostics, vaccines, and therapeutics in the fight against COVID-19.