The effects of different types of Tai Chi exercises on preventing falls in older adults: a systematic review and network meta-analysis.

OBJECTIVES: Few studies comparing the effects of different types of Tai Chi exercises on preventing falls in older adults. We compared the effects for finding an optimal intervention. METHODS: We searched 12 databases, including PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) and so on, from their inception to January 13, 2023. Randomized controlled trials incorporating different types of Tai Chi for preventing falls in older adults were included. The outcome measures were the incidence of falls and Berg Balance Scale (BBS). Network meta-analysis (NMA) was conducted using Stata 15.1 based on a frequentist framework. RESULTS: Seventeen trials were eligible, including 3470 participants and four types of Tai Chi. They were 24-form simplified Tai Chi (24-form), Yang style Tai Chi (Yang style), Sun style Tai Chi (Sun style) and Tai Chi exercise program (TCEP). In paired meta-analysis, for incidence of falls, 24-form (Relative Risk (RR) = 0.59, 95% confidence interval (CI) [0.40, 0.86]) was more efficient than the control group. For BBS outcome, 24-form (MD (mean difference) = 2.32, 95% CI [1.42, 3.22]) was better than the control group. In the NMA, the results of incidence of falls were as follows: 24-form > Yang style > Sun style > control > TCEP. The rank probability of BBS was as follows: 24-form > TCEP > Yang style > control. CONCLUSION: Among the four types of Tai Chi studied, the 24-form simplified Tai Chi has shown better efficacy than other types.

Constructing Supported Cell Membranes with Controllable Orientation.

Membrane proteins play important roles in various cellular processes. Methods that can retain their structure and membrane topology information during their characterization are desirable for understanding their structure-function behavior. Here, we use giant plasma membrane vesicles (GPMVs) to form the supported cell membrane and develop a blotting method to control the orientation of the deposited cell membrane in order to study membrane proteins from either the extracellular or the cytoplasmic sides. We show that the membrane orientation can be retained in the directly-deposited membrane and the deposited membrane on mica can be blotted onto glass to reverse the membrane orientation. We used Aquaporin 3 (AQP3), an abundant native transmembrane protein in Hela cells, as a target to examine the cell membrane orientation in the directly-deposited and reversed membrane platforms. The immunostaining of antibodies targeting either the cyto-domain or ecto-domain of AQP3 shows that the intracellular side of the cell membrane faced the bulk aqueous environment when the GPMVs spontaneously ruptured on the support and that the membrane orientation was reversed after blotting. With this blotting method, we can thus control the orientation of the supported cell membrane to study membrane protein functions and structures from either side of the cell plasma membrane.

Cytosolic Transport of Nanoparticles through Pressurized Plasma Membranes for Molecular Delivery and Amplification of Intracellular Fluorescence.

Transporting nanoparticles into live cells is important for drug delivery and other related applications. We found that cells exposed to hypoosmotic pressures can internalize substantial quantities of gold nanoparticles. Importantly, these nanoparticles can circumvent normal intracellular traffic and be transported directly into the cytosol, without the need for surface functionalization. In contrast, nanoparticles endocytosed at physiological osmolality are segregated inside endocytic organelles and are not able to reach the cytosol. Cytosolic internalization was observed for nanoparticles of various sizes and materials, with minimal short- or long-term damage induced by the internalized particles. Thus, our strategy can be used as a delivery platform for a range of applications from therapeutics to medical imaging. As examples, we demonstrated rapid delivery of membrane-impermeable molecules to the cytosol by using nanoparticles as carriers and the use of nanoparticles assembled within the cytosol as plasmonic nanoantenna to enhance intracellular fluorescence. We propose a model for the mechanisms behind nanoparticle internalization through pressurized plasma membranes via the release of lateral pressures. Such characterizations may constitute a foundation for developing new technologies, including nanoparticle-based drug delivery.