Nanoengineered Red Blood Cells Loaded with TMPRSS2 and Cathepsin L Inhibitors Block SARS-CoV-2 Pseudovirus Entry into Lung ACE2+ Cells.

The enzymatic activities of Furin, Transmembrane serine proteinase 2 (TMPRSS2), Cathepsin L (CTSL), and Angiotensin-converting enzyme 2 (ACE2) receptor binding are necessary for the entry of coronaviruses into host cells. Precise inhibition of these key proteases in ACE2+ lung cells during a viral infection cycle shall prevent viral Spike (S) protein activation and its fusion with a host cell membrane, consequently averting virus entry to the cells. In this study, dual-drug-combined (TMPRSS2 inhibitor Camostat and CTSL inhibitor E-64d) nanocarriers (NCs) are constructed conjugated with an anti-human ACE2 (hACE2) antibody and employ Red Blood Cell (RBC)-hitchhiking, termed "Nanoengineered RBCs," for targeting lung cells. The significant therapeutic efficacy of the dual-drug-loaded nanoengineered RBCs in pseudovirus-infected K18-hACE2 transgenic mice is reported. Notably, the modular nanoengineered RBCs (anti-receptor antibody+NCs+RBCs) precisely target key proteases of host cells in the lungs to block the entry of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), regardless of virus variations. These findings are anticipated to benefit the development of a series of novel and safe host-cell-protecting antiviral therapies.

[Preparation of liposomal artesunate dry powder inhalers and the effect on the acute lung injury of rats].

Artesunate is one of artemisinin derivatives with anti-malarial and anti-inflammatory activities though its water solubility and bioavailability are low. Acute lung injury (ALI) is a seriously dispersive lung disease with a high mortality. In this study, artesunate liposomes were prepared with the film dispersion method, and then lyophilized to obtain the liposomal artesunate dry powder inhalers(LADPIs). The LADPIs were pulmonary-delivered into the lung to treat ALI in rats. The artesunate liposomes had the capsulation efficiency of 71.4%, the particle size of 47.3 nm, and the zeta potential of -13.7 m V. The LADPIs had the aerodynamic particle size of 4.2 µm and the fine particle fraction (FPF) of 34.5%. ALI was established in rats by instilling lipopolysaccharide (LPS) into the lungs. The rats quickly showed a reduction in movement and acceleration in breath followed by diarrhea and so on. The LADPIs were directly administrated into the lungs of ALI rats through airways after 1 h of LPS challenge. The treatment induced a reduction in ALI syndromes. Two inflammatory factors, including TNF-α and IL-6, were significantly reduced by the artesunate powder in the LADPI group similarly to the reduction in the positive drug dexamethasone group (P < 0.05). Therefore, the anti-inflammatory effect of LADPIs contributed to the anti-ALI activity. Furthermore, the liposomal formulation improved drug bioavailability in the lung and increased therapeutic efficiency. The LADPIs are promising medicines for therapy of ALI through local drug administration.

[Ultrasonic microbubbles for glioma-targeted drug delivery].

Ultrasonic microbubbles were used to open blood-brain barriers (BBB) with a reversed and limited behavior feature in the study, which could improve the brain-targeted delivery of anti-tumor drugs. The glioma rat model was prepared. Low-frequency ultrasound was combined with microbubbles to affect the permeability of BBB compared with the permeability of independently administered Evans blue (EB) crossing BBB. Time point and length of ultrasound were investigated whether they affect the permeability of BBB and the damage of brain tissue. The effect of the growth time of glioma on BBB permeability was explored. Only glioma had a very little impact on BBB permeability. However, ultrasonic microbubbles opened the BBB with the features of temporary, limited and reversed behavior and improved EB and magnetic resonance imaging contrast agent penetrating BBB. A length of 30 s ultrasound is appropriate for opening BBB and no damage of brain tissue. Drugs should be injected before ultrasound so that they enter into brain as BBB opening. Ultrasonic microbubbles can open BBB effectively and safely, which improve drugs penetrating BBB under proper time point and length.

[Preparation, in vitro and in vivo evaluation of cataplasm of white mustard seed varnish to prevent asthma].

The aim of the manuscript was to optimize formulations and preparation technologies of cataplasm of white mustard seed varnish, and to evaluate its anti-asthma effect on rats. The single factor experiments included spreading thickness, types of crosslinking agents, dihydroxyaluminum aminoacetate amount, sodium polyacrylate amount, types of adhesive agents with human sense as the evaluation index. Blank cataplasm matrix was optimized by the orthogonal experiment with the amount of glycerine, citric acid, and sodium carboxymethylcellulose as the major influential factors. Initial adhesive force, peeling strength and human sense were as the evaluation index. The optimized formulation of blank cataplasm were as followings: glycerine-water-ethanol-PEG400-dihydroxyaluminum aminoacetate-citric acid-sodium carboxymethylcellulose-sodium carboxymethylcellulose 2 : 8 : 0.8 : 0.4 : 0.07: 0.15 : 0.1 : 0.5. The active ingredients of white mustard seed, corydalis, and gansui root were extracted by alcohol extraction method. Asiasarum volatile oil was extracted by oil extractor. The optimized drug loading amount was 11% with initial adhesive force, peeling strength and human sense as the evaluation index. Asthma rats model were established by sensitized with ovalbumin and nose-scratching time as the evaluation index. High dose (17%) group of drug-loaded cataplasm had the obvious inhibition effect on nose-scratching time of rats (P = 0.037 < 0.05). In comparison, middle dose (11%), low dose (4%) and positive-control groups had no obvious inhibitive effect on rats. White mustard seed cataplasm supplied a novel choice for anti-asthma therapy. And the overall pharmacodynamics assessment will be carried out on molecular level in near future.

Potential and problems in ultrasound-responsive drug delivery systems.

Ultrasound is an important local stimulus for triggering drug release at the target tissue. Ultrasound-responsive drug delivery systems (URDDS) have become an important research focus in targeted therapy. URDDS include many different formulations, such as microbubbles, nanobubbles, nanodroplets, liposomes, emulsions, and micelles. Drugs that can be loaded into URDDS include small molecules, biomacromolecules, and inorganic substances. Fields of clinical application include anticancer therapy, treatment of ischemic myocardium, induction of an immune response, cartilage tissue engineering, transdermal drug delivery, treatment of Huntington's disease, thrombolysis, and disruption of the blood-brain barrier. This review focuses on recent advances in URDDS, and discusses their formulations, clinical application, and problems, as well as a perspective on their potential use in the future.

[Effect of RMP-7 and its derivatives on the transportation of liposome into the brain].

AIM: To study the action of RMP-7 and its derivative on transporting liposome across the blood brain barrier (BBB) into the brain. METHODS: RMP-7 and DSPE-PEG-NHS [[1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-n-[poly (ethylene-glycol)]-hydroxy succinamide]] were conjugated together in mild condition and MALDI-TOF-MS (Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry) was used to determine their molecular ratio. An in vitro BBB model was established and used to determine in vitro bioactivity of RMP-7 and its derivative. The fluorescence of brain slices and the Evens Blue (EB) concentration in the brain, liver, spleen, lung and kidney of each group were used to evaluate the in vivo bioactivity of RMP-7 and its derivative on transporting liposome across the BBB. RESULTS: The average molecular weight (MW) of the reaction product was 4,900, while those of DSPE-PEG-NHS and RMP-7 were 3,224 and 1,098. The results demonstrated that RMP-7 was conjugated to DSPE-PEG-NHS at the molecular ratio of 1:1, so the product was DSPE-PEG-RMP-7. RMP-7 and DSPE-PEG-RMP-7 was shown to improve the transporting of peralcohol enzyme across the in vitro BBB model 2-3 times higher than the peralcohol enzyme only. DSPE-PEG-RMP-7 could facilitate the transporting of EB into brain more easily than RMP-7. CONCLUSION: Both RMP-7 and DSPE-PEG-RMP-7 could facilitate the transporting of liposome across the BBB, especially DSPE-PEG-RMP-7.