Exosomes rewire the cartilage microenvironment in osteoarthritis:from intercellular communication to therapeutic strategies

Osteoarthritis(OA)is a prevalent degenerative joint disease characterized by cartilage loss and accounts for a major source of pain and disability worldwide.However,effective strategies for cartilage repair are lacking,and patients with advanced OA usually need joint replacement.Better comprehending OA pathogenesis may lead to transformative therapeutics.Recently studies have reported that exosomes act as a new means of cell-to-cell communication by delivering multiple bioactive molecules to create a particular microenvironment that tunes cartilage behavior.Specifically,exosome cargos,such as noncoding RNAs(ncRNAs)and proteins,play a crucial role in OA progression by regulating the proliferation,apoptosis,autophagy,and inflammatory response of joint cells,rendering them promising candidates for OA monitoring and treatment.This review systematically summarizes the current insight regarding the biogenesis and function of exosomes and their potential as therapeutic tools targeting cell-to-cell communication in OA,suggesting new realms to improve OA management.

Ultrabright bimetallic AuAg complex:From luminescence mechanism to biological application

Metal clusters have attracted wide interests due to their unique electronic and optical properties,but the low luminescence quantum yield(QY)prevents them from potential biomedical applications.In this work,silver-doped Au nanoclusters(NCs)are shown to be able to improve the QY of metal clusters.We succeeded in synthesizing ultrabright glutathione(GSH)protected AuAg clusters with 10.8%QY by a one-pot route.Their florescence is about 7.5 times brighter than pure Au NCs,with super photostability and good biocompatibility in physiological environment.Based on density functional theory(DFT)calculations,we investigated the electronic structures and optical properties of the AuAg NCs.The results show that the increase of the density of states of the lowest unoccupied molecular orbital(LUMO)leads to the fluorescence enhancement.In addition,two-photon excitation fluorescence imaging has been performed to show their great potential for biomedicine.

The Influence of Contemporary Dance,Used in the Choreographic Process of Chinese Mongolian dance

China is a country that has 55 nationalities.The Chinese folk dance is a dance that also has 55 varieties of folk dances.Chinese Mongolian dance is one of those folk dances.The Chinese Mongolian dance mentioned in this paper can also be interpreted as an academically trained Chinese Mongolian dance.

Highly efficient catalytic scavenging of oxygen free radicals with graphene-encapsulated metal nanoshields

Normal levels of oxygen free radicals play an important role in cellular signal transduction, redox homeostasis, regulatory pathways, and metabolic processes. However, radiolysis of water induced by high-energy radiation can produce excessive amounts of exogenous oxygen free radicals, which cause severe oxidative damages to all cellular components, disrupt cellular structures and signaling pathways, and eventually lead to death. Herein, we show that hybrid nanoshields based on single-layer graphene encapsulating metal nanoparticles exhibit high catalytic activity in scavenging oxygen superoxide （·O2^-）, hydroxyl （·OH）, and hydroperoxyl （HO2·） free radicals via electron transfer between the single-layer graphene and the metal core, thus achieving biocatalytic scavenging both in vitro and in vivo. The levels of the superoxide enzyme, DNA, and reactive oxygen species measured in vivo dearly show that the nanoshields can efficiently eliminate harmful oxygen free radicals at the cellular level, both in organs and circulating blood. Moreover, the nanoshields lead to an increase in the overall survival rate of gamma ray-irradiated mice to up to 90%, showing the great potential of these systems as protective agents against ionizing radiation.

Catalytic PtPd bimetal nanocrystals with high-index facets for radiation injury repair

Radiotherapy is one of the most important clinical cancer treatments,which works mainly by delive ring a prescribed radiation dose to the tumor tissues.However,high doses of radiation may also lead many irreversible damages to the surrounding normal tissues.Thereby,how to effectively reduce these sideeffects has been a significant factor in influencing cancer therapeutic effect.In this work,we synthesized the hollow PtPd nanocubes with high-index facets,and investigated the radiation protection capability in vitro and in vivo.Our results showed the PtPd nanocrystals can decrease the ROS level and improve the survival rate of radiated cells.Meanwhile,survival rate of radiated mice can significantly increase from 0 to 30%after PtPd treatment.Consequently,the enzyme and ROS level in radiated mice can be recovered.