Reformulating lipid nanoparticles for organ-targeted mRNA accumulation and translation.

Fully targeted mRNA therapeutics necessitate simultaneous organ-specific accumulation and effective translation. Despite some progress, delivery systems are still unable to fully achieve this. Here, we reformulate lipid nanoparticles (LNPs) through adjustments in lipid material structures and compositions to systematically achieve the pulmonary and hepatic (respectively) targeted mRNA distribution and expression. A combinatorial library of degradable-core based ionizable cationic lipids is designed, following by optimisation of LNP compositions. Contrary to current LNP paradigms, our findings demonstrate that cholesterol and phospholipid are dispensable for LNP functionality. Specifically, cholesterol-removal addresses the persistent challenge of preventing nanoparticle accumulation in hepatic tissues. By modulating and simplifying intrinsic LNP components, concurrent mRNA accumulation and translation is achieved in the lung and liver, respectively. This targeting strategy is applicable to existing LNP systems with potential to expand the progress of precise mRNA therapy for diverse diseases.

Janus Membranes Patch Achieves High-Quality Tendon Repair: Inhibiting Exogenous Healing and Promoting Endogenous Healing.

The imbalance between endogenous and exogenous healing is the fundamental reason for the poor tendon healing. In this study, a Janus patch was developed to promote endogenous healing and inhibit exogenous healing, leading to improved tendon repair. The upper layer of the patch is a poly(dl-lactide-co-glycolide)/polycaprolactone (PLGA/PCL) nanomembrane (PMCP-NM) modified with poly(2-methylacryloxyethyl phosphocholine) (PMPC), which created a lubricated and antifouling surface, preventing cell invasion and mechanical activation. The lower layer is a PLGA/PCL fiber membrane loaded with fibrin (Fb) (Fb-NM), serving as a temporary chemotactic scaffold to regulate the regenerative microenvironment. In vitro, the Janus patch effectively reduced 92.41% cell adhesion and 79.89% motion friction. In vivo, the patch inhibited tendon adhesion through the TGF-ß/Smad signaling pathway and promoted tendon maturation. This Janus patch is expected to provide a practical basis and theoretical guidance for high-quality soft tissue repair.

Biomechanical Scaffolds of Decellularized Heart Valves Modified by Electrospun Polylactic Acid.

Enhancing the mechanical properties and cytocompatibility of decellularized heart valves is the key to promote the application of biological heart valves. In order to further improve the mechanical properties, the electrospinning and non-woven processing methods are combined to prepare the polylactic acid (PLA)/decellularized heart valve nanofiber-reinforced sandwich structure electrospun scaffold. The effect of electrospinning time on the performance of decellularized heart valve is investigated from the aspects of morphology, mechanical properties, softness, and biocompatibility of decellularized heart valve. Results of the mechanical tests show that compared with the pure decellularized heart valve, the mechanical properties of the composite heart valve were significantly improved with the tensile strength increasing by 108% and tensile strain increased by 571% when the electrospinning time exceeded 2 h. In addition, with this electrospinning time, the composite heart valve has a certain promoting effect on the human umbilical vein endothelial cells proliferation behavior. This work provides a promising foundation for tissue heart valve reendothelialization to lay the groundwork for organoid.

Strengthened Decellularized Porcine Valves via Polyvinyl Alcohol as a Template Improving Processability.

The heart valve is crucial for the human body, which directly affects the efficiency of blood transport and the normal functioning of all organs. Generally, decellularization is one method of tissue-engineered heart valve (TEHV), which can deteriorate the mechanical properties and eliminate allograft immunogenicity. In this study, removable polyvinyl alcohol (PVA) is used to encapsulate decellularized porcine heart valves (DHVs) as a dynamic template to improve the processability of DHVs, such as suturing. Mechanical tests show that the strength and elastic modulus of DHVs treated with different concentrations of PVA significantly improve. Without the PVA layer, the valve would shift during suture puncture and not achieve the desired suture result. The in vitro results indicate that decellularized valves treated with PVA can sustain the adhesion and growth of human umbilical vein endothelial cells (HUVECs). All results above show that the DHVs treated with water-soluble PVA have good mechanical properties and cytocompatibility to ensure post-treatment. On this basis, the improved processability of DHV treated with PVA enables a new paradigm for the manufacturing of scaffolds, making it easy to apply.

A review of rigid point cloud registration based on deep learning.

With the development of 3D scanning devices, point cloud registration is gradually being applied in various fields. Traditional point cloud registration methods face challenges in noise, low overlap, uneven density, and large data scale, which limits the further application of point cloud registration in actual scenes. With the above deficiency, point cloud registration methods based on deep learning technology gradually emerged. This review summarizes the point cloud registration technology based on deep learning. Firstly, point cloud registration based on deep learning can be categorized into two types: complete overlap point cloud registration and partially overlapping point cloud registration. And the characteristics of the two kinds of methods are classified and summarized in detail. The characteristics of the partially overlapping point cloud registration method are introduced and compared with the completely overlapping method to provide further research insight. Secondly, the review delves into network performance improvement summarizes how to accelerate the point cloud registration method of deep learning from the hardware and software. Then, this review discusses point cloud registration applications in various domains. Finally, this review summarizes and outlooks the current challenges and future research directions of deep learning-based point cloud registration.

Polylactic acid scaffold with directional porous structure for large-segment bone repair.

Biodegradable porous scaffolds with different structure, porosity, and strength play a critical role in the repair and regeneration of defects in bone tissue engineering by changing the proliferation condition for cell. In this study, polylactic acid (PLA) scaffold with directional porous structure is designed and fabricated using the method of ice template and phase inversion for speeding up bone repair by promoting the growth and proliferation of bone cells. The morphology, mechanical properties, hydrophilicity, and wicking properties of PLA scaffolds were characterized by scanning electron microscope, universal testing machine, contact angle tester and wicking rate test, respectively. In vitro biocompatibility has been investigated through measuring cell adhesion, proliferation, and viability on PLA scaffold with directional porous structure. Prepared PLA scaffold was implanted into animals to observe the repair mechanism of large-sized bone defects. This study proposes a novel bioporous scaffold design to induce osteocyte growth at the rat calvaria with a directional pore structure, and the scaffold edges were integrated with the calvaria at week 12, effectively promoting the repair and regeneration of defective bone tissue.

Discovery of a small molecule inhibitor of cullin neddylation that triggers ER stress to induce autophagy.

Protein neddylation is catalyzed by a three-enzyme cascade, namely an E1 NEDD8-activating enzyme (NAE), one of two E2 NEDD8 conjugation enzymes and one of several E3 NEDD8 ligases. The physiological substrates of neddylation are the family members of cullin, the scaffold component of cullin RING ligases (CRLs). Currently, a potent E1 inhibitor, MLN4924, also known as pevonedistat, is in several clinical trials for anti-cancer therapy. Here we report the discovery, through virtual screening and structural modifications, of a small molecule compound HA-1141 that directly binds to NAE in both in vitro and in vivo assays and effectively inhibits neddylation of cullins 1-5. Surprisingly, unlike MLN4924, HA-1141 also triggers non-canonical endoplasmic reticulum (ER) stress and PKR-mediated terminal integrated stress response (ISR) to activate ATF4 at an early stage, and to inhibit protein synthesis and mTORC1 activity at a later stage, eventually leading to autophagy induction. Biologically, HA-1141 suppresses growth and survival of cultured lung cancer cells and tumor growth in in vivo xenograft lung cancer models at a well-tolerated dose. Taken together, our study has identified a small molecule compound with the dual activities of blocking neddylation and triggering ER stress, leading to growth suppression of cancer cells.

Effect of poly (lactic acid) porous membrane prepared via phase inversion induced by water droplets on 3T3 cell behavior.

Phase inversion induced by water droplets has garnered attention in the field of polymer science as a novel method for preparing porous membranes. This study investigates the effect of the porous structure of poly (lactic acid) (PLA) membranes prepared through phase inversion induced by water droplets at four different temperatures (25, 50, 75, and 100 °C) on the morphology and proliferation of 3T3 cells. The surface properties of the PLA porous membrane, including pore size, pore size distribution, surface roughness, surface hydrophilicity, and cytocompatibility with 3T3 cells, were evaluated. The results indicated that the synthesized PLA membrane had two surfaces with different structures. The upper surface in contact with the water droplets during preparation contained uniformly distributed micropores, whereas the bottom surface was smooth and composed of small particles in contacted with the mold. The upper surface showed high cytocompatibility with 3T3 cells, and the 3T3 cells migrated and grew within the pores at 25 °C. In contrast, the bottom surface exhibited low biocompatibility with the 3T3 cells. Our study has wide-ranging implications and will improve the fabrication and implementation of 3D cultured scaffolds with excellent cytocompatibility.

Triazenyl Alkynes as Versatile Building Blocks in Multicomponent Reactions: Diastereoselective Synthesis of ß-Amino Amides.

Multicomponent reactions (MCRs) are powerful tool for the construction of polyfunctional molecules in an operationally simple and atom-economic manner, and the discovery of novel MCRs requests various building blocks. Herein, triazenyl alkynes were disclosed as versatile building blocks in a multicomponent reaction with carboxylic acids, aldehydes and anilines to furnish ß-amino amides with the achievement of high diastereoselectivity and structural diversity. In this process, triazenyl alkynes were bifunctional so that the alkyne moiety acts as C2 fragment and triazene serves as directing group to modulate the transition state thus achieving high diastereoselectivity, in consistence with DFT calculations. Furthermore, the triazenyl group also enables diverse late-stage transformation. This protocol opens a new vision for the discovery of building block and rational design of MCRs.

Redox Cyclization of Amides and Sulfonamides with Nitrous Oxide for Direct Synthesis of Heterocycles.

Herein we report a redox cyclization of amides and sulfonamides with nitrous oxide (N2O) for the direct synthesis of heterocycles. Various amides and sulfonamides could undergo directed ortho metalation (DoM) by treatment with BuLi, and the lithium intermediate could be trapped by N2O gas to achieve redox cyclization. N2O serves as a N-atom donor to mediate the intramolecular coupling of lithium species toward heterocycle formation with free external oxidant. This protocol offers a direct synthesis of heterocycles with features of readily available starting materials, simple operation, and a broad substrate scope.

Association of susceptibility to septic shock with platelet endothelial cell adhesion molecule-1 gene Leu125Val polymorphism and serum sPECAM-1 levels in sepsis patients.

Sepsis is a systemic inflammatory response to infection and includes severe sepsis, septic shock and death. Platelet endothelial cell adhesion molecule-1 (PECAM-1) is one cell adhesion molecule expressed on platelets and leukocytes. It regulates platelet activation and mediates transendothelial migration of leukocytes, thus maintaining the integrity of the vasculature. There are some animal experiments associated with the protective role of PECAM-1 against septic shock. However few host genetic risk factors have been identified for sepsis severity and susceptibility to septic shock. A case-control study was conducted, which included 217 patients with sepsis and 90 control subjects recruited from our hospital. One single nucleotide polymorphisms (SNP) of PECAM-1 gene Leu125Val (C373G) was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Serum soluble PECAM-1 (sPECAM-1) levels were determined by enzyme-linked immunosorbent assay (ELISA). Our results showed that the CG and GG genotypes of SNP in Leu125Val of PECAM-1 (rs668: C>G) was significantly associated with increased susceptibility to septic shock compared with CC genotype in sepsis patients (CG genotype, OR: 2.493, 95% CI: 1.175~5.287, P = 0.016; GG genotype: OR: 3.328, 95% CI: 1.445~7.666, P = 0.004). The serum levels of sPECAM-1 in the sepsis patients (47.1 ± 17.5 ng/ml) were significantly higher than those in the healthy controls (61.3 ± 20.9 ng/ml, P<0.01). Among sepsis patients, the serum levels of sPECAM-1 were significantly higher in CG and GG genotype than in CC genotype. In septic shock patients, nonsurvivors (83.7 ± 12.6 ng/ml, n = 69) had a significantly higher serum sPECAM-1 level than the survivors (76.9 ± 12.7 ng/ml, n = 53) (P<0.01). In conclusion, PECAM-1 Leu125Val polymorphism and its sPECAM-1 levels are associated with sepsis severity and susceptibility to septic shock.

[The clinical studies of 51 patients with thrombotic thrombocytopenic purpura].

OBJECTIVE: To comprehensively analyze the clinical characteristics, treatment strategies and outcome of patients with thrombotic thrombocytopenic purpura (TTP). METHODS: A retrospective survey of 51 TTP patients confirmed in our database. Relevant statistical analyzes were performed by GraphPad Prism 5 software. RESULTS: 51 cases of patients with acquired TTP were identified as idiopathic TTP. In our study, only 18 cases (35.29%) had typical pentalogy of TTP, where thrombocytopenia (100.00%), microangiopathic hemolytic anemia (92.16%) and neurologic abnormalities (88.24%) were more common than fever (72.55%) and renal abnormalities (70.59%). Plasma ADAMTS13 activity was detected in 37 patients with TTP with ADAMTS13 deficiency confirmed in 31 patients (83.78%). Plasma exchange with response of 72.3% was still the preferred strategy in TTP with individuation. Among 36 survival TTP patients, 8 patients (22.22%) relapsed. 15 patients (29.41%) died in our study. The mean ages of responders and deaths were of (37.5±14.5) and (50.1±18.9) respectively; whereas total bilirubin level of responders and deaths were of (43.3±23.5)µmol/L and (63.7±39.7) µmol/L respectively, the differences were statistically significant. Conversely, body temperature, WBC, HGB, PLT, serum creatinine and LDH showed no significant differences (P>0.05). CONCLUSION: The diagnosis of TTP was based on comprehensive analysis of clinical manifestations. Plasma ADAMTS13 activity test had a higher clinical practical value. The therapeutic alliance with corticosteroids, immunosuppressive agents and Rituximab significantly improved its outcome. The age and high total bilirubin level at onset were associated with less sensitive to plasmapheresis and poor prognosis.

[Gene analysis and pathogenesis in 40 patients with hemophilia B].

Hemophilia B (HB) is a recessive X-linked inherited disorder, the pathogenesis of HB is deficiency or functional abnormalities of coagulation factor IX, which is caused by F9 gene mutations. To explore the mechanism of its molecular pathology, 40 patients with HB were studied with polymerase chain reaction (PCR) and direct sequencing. The diagnosis of HB patients were based on clinical manifestation and deficient factor IX activity in plasma. DNA was routinely extracted from peripheral blood cells of the patients and their relatives, all the 8 exons and their flanking boundaries were amplified by PCR, and the PCR products were screened by direct sequencing. Mutations which were found in study need to exclude polymorphism. The results showed that 34 mutations were confirmed in 40 HB patients, including 6 nonsense mutations, 24 missense mutations, 2 splice site mutations and 2 frame mutations for 1 or 2 nucleotide insertion. After retrieved, 4 missense mutations and 1 frameshift mutation were found for the first time. Among the 34 mutations, 2 mutations in signal peptide, 7 mutations in propeptide and gla domain, 7 mutations in epidermal growth factor-like domain, 3 mutations in activation domain, 15 mutations in serine protease or catalytic domain. It is concluded that gene analysis can directly explain molecular mechanism of hemophilia B and also provides the foundation for further studies to the function of coagulation factor IX. There is obvious heterogeneity in F9 gene mutation and missense mutation is still the main way of mutation, which are closely related to clinical features. DNA sequencing and linkage analysis are efficient methods for HB carriers and prenatal gene diagnosis.