Prime editing using CRISPR-Cas12a and circular RNAs in human cells.

Genome editing with prime editors based on CRISPR-Cas9 is limited by the large size of the system and the requirement for a G/C-rich protospacer-adjacent motif (PAM) sequence. Here, we use the smaller Cas12a protein to develop four circular RNA-mediated prime editor (CPE) systems: nickase-dependent CPE (niCPE), nuclease-dependent CPE (nuCPE), split nickase-dependent CPE (sniCPE) and split nuclease-dependent CPE (snuCPE). CPE systems preferentially recognize T-rich genomic regions and possess a potential multiplexing capacity in comparison to corresponding Cas9-based systems.

An advanced strategy for quality evaluation of Xinyi Biyan Pill by UPLC-DAD fingerprinting combined with multi-components UPLC-MS/MS analysis.

Xinyi Biyan Pill (XBP) is a classical Chinese patent medicine and widely used to treat acute and chronic or allergic rhinitis in clinical practice. This study aimed to establish and validate a comprehensive strategy combining ultra-performance liquid chromatography with diode array detector (UPLC-DAD) fingerprinting and multi-component quantification for quality evaluation of XBP. In the fingerprint analysis, 32 peaks were selected as common peaks and used to evaluate the similarity of 12 batches of XBP.

[Improvement of Preparation Method of Rats Platelet-Rich Plasma and Quality Detection].

Objective: To optimize the single centrifugation preparation protocol of rat platelet-rich plasma (PRP).

Methods: The arterial blood of rats obtained by carotid artery intubation was collected by heparin sodium anticoagulant tubes, and then the blood divided into sterile EP tubes, adjusting the red blood cell concentration with normal saline, while rat PRP was prepared by centrifugation under different conditions (the centrifugal force was 200×-240×, and the centrifugal time was 8-12 min). Subsequently, the blood cell count and quality evaluation of anticoagulat whole blood and PRP were performed by hematology analyzer and flow cytometry, respectively, and the differences between different groups were compared.

Discovery of deaminase functions by structure-based protein clustering.

The elucidation of protein function and its exploitation in bioengineering have greatly advanced the life sciences. Protein mining efforts generally rely on amino acid sequences rather than protein structures. We describe here the use of AlphaFold2 to predict and subsequently cluster an entire protein family based on predicted structure similarities.

Extracellular Matrix-Mimetic Peptide Scaffolds Prolonged the Hypothermic Preservation of Stem Cells for Storage and Transportation.

Encouraging advances in both regenerative medicine and tissue engineering with stem cells require a short-term preservation protocol to provide enough time for quality control or the transportation of cell products from manufacturing facilities to clinical destinations. The hypothermic preservation of stem cells under refrigerated conditions (2-8 °C) in their specific culture medium provides an alternative and low-cost method for cryopreservation or commercial preservation fluid for short-term storage. However, most stem cells are vulnerable to hypothermia, which might result in cell damage from the cooling process and the lack of extracellular matrix (ECM).

[Factors Affecting the Preservation of Human Peripheral Blood Mononuclear Cells at 4 ℃].

Objective: To analyze the preservation effect and related influencing factors of human peripheral blood mononuclear cells under serum-free condition at 4 ℃.

Methods: Human peripheral blood mononuclear cells were isolated by density gradient centrifugation, and stored at 4 ℃ under different cell concentrations, supplemented with human serum albumin, and glucose. The cell viability, total cell number, viable cell number and cell phenotype were detected during preservation of 72 h.

Efficacy of Aerosol Reduction Measures for Dental Aerosol Generating Procedures.

Aerosol particles generated by dental procedures could facilitate the transmission of infectious diseases and contain carcinogen particles. Such particles can penetrate common surgical masks and reach the lungs, leading to increased risk for dental care professionals. However, the risk of inhaling contaminated aerosol and the effectiveness of aerosol reduction measures in dental offices remain unclear.

Controlled tough bioadhesion mediated by ultrasound.

Tough bioadhesion has important implications in engineering and medicine but remains challenging to form and control. We report an ultrasound (US)-mediated strategy to achieve tough bioadhesion with controllability and fatigue resistance. Without chemical reaction, the US can amplify the adhesion energy and interfacial fatigue threshold between hydrogels and porcine skin by up to 100 and 10 times.

Dual-sensitized Eu(III)/Tb(III) complexes exhibiting tunable luminescence emission and their application in cellular-imaging.

Two novel dual-photosensitized stable complexes, namely [Eu(dpq)(BTFA)] (1) and [Tb(dpq)(BTFA)] (2), have been successfully assembled a mixed ligand approach using dipyrido[3,2-:2',3'-]quinoxaline (dpq) and 3-benzoyl-1,1,1-trifluoroacetone (BTFA). The crystallographic data reveal mononuclear lanthanide cores in both 1 and 2, in which each eight-coordinated Ln(III) ion is located in a slightly distorted dodecahedron (). The room-temperature photoluminescence spectra of complexes 1 and 2 indicate that both BTFA and dpq can effectively sensitize Eu(III) and Tb(III) characteristic luminescence.

Cobalt-catalyzed Divergent Markovnikov and Anti-Markovnikov Hydroamination.

Catalytic hydroamination of the readily available alkenes is among the most straightforward means to construct diverse alkyl amines. To this end, the facile access to both regioselectivity, , Markovnikov or anti-Markovnikov hydroamination, with minimum reaction-parameter alternation, remains challenging. Herein, we report a cobalt-catalyzed highly selective and divergent Markovnikov and anti-Markovnikov hydroamination of alkenes, in which the switch of regioselectivity is achieved simply by the variation of the addition sequence of 9-BBN.

Injectable, Pore-Forming, Perfusable Double-Network Hydrogels Resilient to Extreme Biomechanical Stimulations.

Biological tissues hinge on blood perfusion and mechanical toughness to function. Injectable hydrogels that possess both high permeability and toughness have profound impacts on regenerative medicine but remain a long-standing challenge. To address this issue, injectable, pore-forming double-network hydrogels are fabricated by orchestrating stepwise gelation and phase separation processes.

Needle-free Mental Incisive Nerve Block:In vitro, Cadaveric, and Pilot Clinical Studies.

The present study aimed to optimize Needle-Free Liquid Jet Injection (NFLJI) for Mental Incisive Nerve Blocks (MINB) and evaluate its clinical safety and feasibility. A MINB protocol was developed and optimized by series of NFLJI experiments in soft tissue phantoms and cadavers, then validated in two pilot Randomized Controlled Trials (RCT). The NFLJI penetration depth was found to be directly proportional to the supply pressure and volume.

Molecular modeling-based inclusion mechanism and stability studies of doxycycline and hydroxypropyl-β-cyclodextrin complex for ophthalmic delivery.

The aim of the present study was to prepare a stable complex of doxycycline (Doxy) and hydroxypropyl-β-cyclodextrin (HPβCD) for ophthalmic delivery and investigate the inclusion mechanism and the inclusion effects on the stability of Doxy. The Doxy/HPβCD complex was prepared by solution stirring and then characterized by scanning electron microscopy and ultraviolet spectroscopy. Based on results of nuclear magnetic resonance, molecular model of Doxy/HPβCD complex was established using computational simulation of PM3 method implemented in Gaussian 03.

Doxycycline enhances the inhibitory effects of bevacizumab on corneal neovascularization and prevents its side effects.

Purpose: To investigate the combination therapeutic effects of topical doxycycline temperature-sensitive hydrogel (DTSH) and bevacizumab on corneal neovascularization (CNV) and corneal wound healing (CWH) and to explore the underlying mechanisms of doxycycline on CNV and CWH.

Methods: Rats were treated with a saline solution, topical DTSH (0.1%), topical bevacizumab (2.

The effect of doxycycline temperature-sensitive hydrogel on inhibiting the corneal neovascularization induced by BFGF in rats.

Background: To study the effect of doxycycline temperature-sensitive hydrogel (DTSH) on inhibiting the corneal neovascularization (NV) induced by the basic fibroblast growth factor (bFGF).

Methods: Corneal NV was induced by slow-release polymer pellets containing bFGF, using a rat corneal pocket model. After being implanted with bFGF pellets, the female Sprague-Dawley rats were randomly divided into seven groups (12 rats/group).