Metabolic engineering of Saccharomyces cerevisiae for chelerythrine biosynthesis.

BACKGROUND: Chelerythrine is an important alkaloid used in agriculture and medicine. However, its structural complexity and low abundance in nature hampers either bulk chemical synthesis or extraction from plants. Here, we reconstructed and optimized the complete biosynthesis pathway for chelerythrine from (S)-reticuline in Saccharomyces cerevisiae using genetic reprogramming. RESULTS: The first-generation strain Z4 capable of producing chelerythrine was obtained via heterologous expression of seven plant-derived enzymes (McoBBE, TfSMT, AmTDC, EcTNMT, PsMSH, EcP6H, and PsCPR) in S. cerevisiae W303-1 A. When this strain was cultured in the synthetic complete (SC) medium supplemented with 100 µM of (S)-reticuline for 10 days, it produced up to 0.34 µg/L chelerythrine. Furthermore, efficient metabolic engineering was performed by integrating multiple-copy rate-limiting genes (TfSMT, AmTDC, EcTNMT, PsMSH, EcP6H, PsCPR, INO2, and AtATR1), tailoring the heme and NADPH engineering, and engineering product trafficking by heterologous expression of MtABCG10 to enhance the metabolic flux of chelerythrine biosynthesis, leading to a nearly 900-fold increase in chelerythrine production. Combined with the cultivation process, chelerythrine was obtained at a titer of 12.61 mg per liter in a 0.5 L bioreactor, which is over 37,000-fold higher than that of the first-generation recombinant strain. CONCLUSIONS: This is the first heterologous reconstruction of the plant-derived pathway to produce chelerythrine in a yeast cell factory. Applying a combinatorial engineering strategy has significantly improved the chelerythrine yield in yeast and is a promising approach for synthesizing functional products using a microbial cell factory. This achievement underscores the potential of metabolic engineering and synthetic biology in revolutionizing natural product biosynthesis.

B16F10 Cell Membrane-Based Nanovesicles for Melanoma Therapy Are Superior to Hyaluronic Acid-Modified Nanocarriers.

Some cancer cell membrane (CCM)-derived nanovesicles show strong homing effects and are used for targeted cancer therapy. By co-constructing the B16F10 cell membrane with a PEGylated phospholipid membrane, a new nanocarrier with a composite nanocrown structure was developed, which can evade immune recognition and actively target homologous melanoma. The nanocrowns have an encapsulation efficiency of more than 90% for paclitaxel and showed no significant difference (p > 0.05) from the PEGylated phospholipid membrane vesicles. Compared with the hyaluronic acid-modified PEGylated phospholipid membrane vesicles, the biomimetic nanocrowns enhanced the escape of nanovesicles from reticuloendothelial cells in vitro and extended the circulation time in vivo; moreover, the nanocrowns showed superior melanoma-targeted drug delivery capability and improved anticancer effects of paclitaxel as demonstrated by the inhibition of B16F10 cell proliferation and induction of apoptosis by interfering with microtubule formation. In contrast, the modification of hyaluronic acid did not increase the targeting capacity or antitumor effects of the nanocrowns, confirming that the superior targeting capacity was mediated by the exposed homologous CCMs rather than by hyaluronic acid. Our results demonstrate the potential of using biomimetic nanocrowns for active melanoma-targeted therapy.

A novel multi-functionalized multicellular nanodelivery system for non-small cell lung cancer photochemotherapy.

BACKGROUND: A red blood cell membrane (RBCm)-derived drug delivery system allows prolonged circulation of an antitumor treatment and overcomes the issue of accelerated blood clearance induced by PEGylation. However, RBCm-derived drug delivery systems are limited by low drug-loading capacities and the lack of tumor-targeting ability. Thus, new designs of RBCm-based delivery systems are needed. RESULTS: Herein, we designed hyaluronic acid (HA)-hybridized RBCm (HA&RBCm)-coated lipid multichambered nanoparticles (HA&RBCm-LCNPs) to remedy the limitations of traditional RBCm drug delivery systems. The inner core co-assembled with phospholipid-regulated glycerol dioleate/water system in HA&RBCm-LCNPs met the required level of blood compatibility for intravenous administration. These newly designed nanocarriers had a honeycomb structure with abundant spaces that efficiently encapsulated paclitaxel and IR780 for photochemotherapy. The HA&RBCm coating allowed the nanocarriers to overcome the reticuloendothelial system barrier and enhanced the nanocarriers specificity to A549 cells with high levels of CD44. These properties enhanced the combinatorial antitumor effects of paclitaxel and IR780 associated with microtubule destruction and the mitochondrial apoptotic pathway. CONCLUSIONS: The multifunctional HA&RBCm-LCNPs we designed expanded the functionality of RBCm and resulted in a vehicle for safe and efficient antitumor treatment.

Functional oral nanoparticles for delivering silibinin and cryptotanshinone against breast cancer lung metastasis.

BACKGROUND: Breast cancer lung metastasis occurs in more than 60% of all patients with breast cancer, and most of those afflicted by it eventually die of recurrence. The tumor microenvironment plays vital roles in metastasis. Modulating the tumor microenvironment via multiple pathways could efficiently prevent or inhibit lung metastasis. Silibinin and cryptotanshinone are natural plant products that demonstrate anti-metastasis effects and modulate the tumor microenvironment via different pathways. However, they have poor aqueous solubility, membrane permeability, and oral bioavailability. Oral drug administration may help improve the quality of life and compliance of patients with breast cancer, primarily under long-term and/or follow-up therapy. Herein, we developed poly-N-(2-hydroxypropyl) methacrylamide (pHPMA)-coated wheat germ agglutinin-modified lipid-polymer hybrid nanoparticles, co-loaded with silibinin and cryptotanshinone (S/C-pW-LPNs). We assessed their oral bioavailability, and evaluated their anti-metastasis efficacy in a 4T1 breast cancer tumor-bearing nude mouse model. RESULTS: An in vitro mucus diffusion study revealed that pHPMA enhanced W-LPN mucus penetration. After oral administration, pHPMA enhanced nanoparticle distribution in rat jejunum and substantially augmented oral bioavailability. S/C-W-LPNs markedly increased 4T1 cell toxicity and inhibited cell invasion and migration. Compared to LPNs loaded with either silibinin or cryptotanshinone alone, S/C-pW-LPNs dramatically slowed tumor progression in 4T1 tumor-bearing nude mice. S/C-pW-LPNs presented with the most robust anti-metastasis activity on smooth lung surfaces and mitigated lung metastasis foci. They also downregulated tumor microenvironment biomarkers such as CD31, TGF-ß1, and MMP-9 that promote metastasis. CONCLUSIONS: Silibinin- and cryptotanshinone-co-loaded pW-LPNs efficiently penetrate intestinal barriers, thereby enhancing the oral bioavailability of the drug loads. These nanoparticles exhibit favorable anti-metastasis effects in breast cancer-bearing nude mice. Hence, S/C-pW-LPNs are promising oral drug nanocarriers that inhibit breast cancer lung metastasis.

Advances in next-generation lipid-polymer hybrid nanocarriers with emphasis on polymer-modified functional liposomes and cell-based-biomimetic nanocarriers for active ingredients and fractions from Chinese medicine delivery.

Recently, functional liposomes modified with versatile polymer and cell-based- biomimetic nanoparticles have emerged as the most advanced lipid-polymer hybrid nanocarriers (LPNs) for drug delivery. This review highlights the advances of these two LPNs in the delivery of active ingredients and fractions from Chinese medicine with promising therapeutic, chemopreventive, or chemosensitive effects. To understand their complete potency, the relationship between the nanoparticle characteristics and their in vitro and in vivo performance characteristics has been discussed. Polymer-modified liposomes and cell-based biomimetic nanoparticles are beneficial for improving absorption, modulating release, targeting and overcoming multidrug resistance, and reducing side effects. The associated challenges, current limitations, and opportunities in this field are also discussed.

MOF Capacitates Cyclodextrin to Mega-Load Mode for High-Efficient Delivery of Valsartan.

PURPOSE: To investigate the mechanism of enhancing solubility and bioavailability of water-insoluble drug, valsartan (VAL), with being mega-loaded by cyclodextrin metal organic framework (CD-MOF). METHODS: VAL was successfully mega-loaded into CD-MOF by magnetic agitation of VAL in ethanolic solution. Characterizations including powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), synchrotron radiation-based Fourier transform-infrared spectroscopy (SR-FTIR) 13C solid-state nuclear magnetic resonance spectroscopy ( 13C SS-NMR), nitrogen gas adsorption, and small-angle X-ray scattering (SAXS) were carried out to confirm the mechanism and incorporation behavior of VAL in CD-MOF. Ball milling process combined with molecular modeling was also used to confirm the mechanism. Improvement of bioavailability in vivo was confirmed by pharmacokinetic experiment in beagles. RESULTS: As a carrier with payload 150% higher than conventional CD complexation, CD-MOF included molecules of VAL as complexations in the chambers of (γ-CD)2, and nanoclusters in the confined spherical cages of (γ-CD)6 confirmed by SAXS and 13C SS-NMR. Ball milling combined with molecular modeling inferred that the reduced release rate of the milled CD-MOF with ultrahigh drug payload was mainly due to the partial aggregation of the VAL nanoclusters. The molecules of VAL as nanoclusters in the cages of (γ-CD)6 are critical in dramatically improving the apparent solubility (39.5-fold) and oral bioavailability (1.9-fold) of VAL in contrast to γ-CD inclusion. CONCLUSIONS: The new understanding of drug nanoclusters in CD-MOF will help to design more efficient drug delivery systems using CD-MOF carrier with nanocavities.

Functional lipid polymeric nanoparticles for oral drug delivery: Rapid mucus penetration and improved cell entry and cellular transport.

To improve Biopharmaceutics Classification System class IV drug bioavailability, mucus and underlying intestinal epithelial barriers must be overcome. Hydrophilic nanoparticle coatings may hinder cellular uptake and transport. We integrated hydrophilic, detachable poly(N-(2-hydroxypropyl) methacrylamide) with vitamin B12-modified chitosan into lipid polymeric nanoparticles (H/VC-LPNs) to enhance mucus penetration, intracellular uptake, and transepithelial absorption. Multiple particle tracking revealed accelerated mucus diffusion into porcine mucus in vitro. The nanoparticles increased uptake and intracellular distribution in Caco-2 cells, which may involve intrinsic factor receptor-mediated endocytosis and intercellular tight junctions. Integration of improved mucus penetration and intracellular absorption was confirmed by in vitro internalization kinetics in HT29-MTX/Caco-2 co-cultures and in vivo distribution, transport, and mouse Peyer's patch absorption. H/VC-LPNs substantially increased curcumin bioavailability in rats. A nanocarrier with a dissociable shell, receptor-mediated intracellular penetration, and paracellular transport may be promising for oral curcumin delivery. This study identified the key factors involved in oral bioavailability enhancement.

Efficient (3S)-Acetoin and (2S,3S)-2,3-Butanediol Production from meso-2,3-Butanediol Using Whole-Cell Biocatalysis.

(3S)-Acetoin and (2S,3S)-2,3-butanediol are important platform chemicals widely applied in the asymmetric synthesis of valuable chiral chemicals. However, their production by fermentative methods is difficult to perform. This study aimed to develop a whole-cell biocatalysis strategy for the production of (3S)-acetoin and (2S,3S)-2,3-butanediol from meso-2,3-butanediol. First, E. coli co-expressing (2R,3R)-2,3-butanediol dehydrogenase, NADH oxidase and Vitreoscilla hemoglobin was developed for (3S)-acetoin production from meso-2,3-butanediol. Maximum (3S)-acetoin concentration of 72.38 g/L with the stereoisomeric purity of 94.65% was achieved at 24 h under optimal conditions. Subsequently, we developed another biocatalyst co-expressing (2S,3S)-2,3-butanediol dehydrogenase and formate dehydrogenase for (2S,3S)-2,3-butanediol production from (3S)-acetoin. Synchronous catalysis together with two biocatalysts afforded 38.41 g/L of (2S,3S)-butanediol with stereoisomeric purity of 98.03% from 40 g/L meso-2,3-butanediol. These results exhibited the potential for (3S)-acetoin and (2S,3S)-butanediol production from meso-2,3-butanediol as a substrate via whole-cell biocatalysis.

Performance Analysis of Integrated Wireless Sensor and Multibeam Satellite Networks Under Terrestrial Interference.

This paper investigates the performance of integrated wireless sensor and multibeam satellite networks (IWSMSNs) under terrestrial interference. The IWSMSNs constitute sensor nodes (SNs), satellite sinks (SSs), multibeam satellite and remote monitoring hosts (RMHs). The multibeam satellite covers multiple beams and multiple SSs in each beam. The SSs can be directly used as SNs to transmit sensing data to RMHs via the satellite, and they can also be used to collect the sensing data from other SNs to transmit to the RMHs. We propose the hybrid one-dimensional (1D) and 2D beam models including the equivalent intra-beam interference factor ß from terrestrial communication networks (TCNs) and the equivalent inter-beam interference factor α from adjacent beams. The terrestrial interference is possibly due to the signals from the TCNs or the signals of sinks being transmitted to other satellite networks. The closed-form approximations of capacity per beam are derived for the return link of IWSMSNs under terrestrial interference by using the Haar approximations where the IWSMSNs experience the Rician fading channel. The optimal joint decoding capacity can be considered as the upper bound where all of the SSs' signals can be jointly decoded by a super-receiver on board the multibeam satellite or a gateway station that knows all of the code books. While the linear minimum mean square error (MMSE) capacity is where all of the signals of SSs are decoded singularly by a multibeam satellite or a gateway station. The simulations show that the optimal capacities are obviously higher than the MMSE capacities under the same conditions, while the capacities are lowered by Rician fading and converge as the Rician factor increases. α and ß jointly affect the performance of hybrid 1D and 2D beam models, and the number of SSs also contributes different effects on the optimal capacity and MMSE capacity of the IWSMSNs.

Synergistic treatment of androgenetic alopecia with follicular co-delivery of minoxidil and cedrol in metal-organic frameworks stabilized by covalently cross-linked cyclodextrins.

Androgenetic alopecia seriously affects the physical and mental health of patients. The main clinical therapeutic agent, minoxidil tincture, is challenged by solvent irritation and dose-dependent side effects. Our recent work has identified a biosafety natural product, cedrol, that is synergistic in combination with minoxidil, thereby improving medication safety by substantially reducing the clinical dose of minoxidil. In addition, ccross-linked CD-MOF were designed as carriers for hair follicle delivery, and γ-CD in the carriers was cross-linked by diphenyl carbonate with covalent bonds to protect the CD-MOF from rapid disintegration in an aqueous environment. This improved nanocarrier has a drug loading of 25%, whereas nanocarriers increased drug delivery to the hair follicles through ratchet effect, and increased human dermal papilla cells uptake of drugs via endocytosis pathways mainly mediated by lattice proteins, energy-dependent active transport, and lipid raft-dependent, thus improved cell viability, proliferation, and migration, followed by significantly enhancing the anti-androgenetic alopecia effect, with cedrol focusing on inhibiting 5α-reductase and activating Shh/Gli pathway, and minoxidil, which up-regulated VEGF, down-regulated TGF-ß, and activated ERK/AKT pathway. This drug combination provides a new therapeutic strategy for androgenetic alopecia, while the newly developed cross-linked CD-MOF has been shown to serve as a promising follicular delivery vehicle.

Glutathione-responsive CD-MOFs co-loading honokiol and indocyanine green biomimetic active targeting to enhance photochemotherapy for breast cancer.

Breast cancer has now replaced lung cancer as the most prevalent malignant tumor worldwide, posing a serious health risk to women. We have recently designed a promising option strategy for the treatment of breast cancer. In this work, cyclodextrin metal-organic frameworks with high drug-carrying properties were endo-crosslinked by 3,3'dithiodipropionyl chloride to form cubic phase gel nanoparticles, which were drug-loaded and then coated by MCF-7 cell membranes. After intravenous injection, this multifunctional nanomedicine achieved dramatically homologous targeting co-delivery of honokiol and indocyanine green to the breast tumor. Further, the disulfide bonds in the nanostructures achieved glutathione-responsive drug release, induced tumor cells to produce reactive oxygen species and promoted apoptosis, resulting in tumor necrosis, and at the same time, inhibited Ki67 protein expression, which enhanced photochemotherapy, and resulted in a 94.08 % in vivo tumor suppression rate in transplanted tumor-bearing mice. Thereby, this nanomimetic co-delivery system may have a place in breast cancer therapy due to its simple fabrication process, excellent biocompatibility, efficient targeted delivery of insoluble drugs, and enhanced photochemotherapy.

Identification of prognosis-related gene features in low-grade glioma based on ssGSEA.

Low-grade gliomas (LGG) are commonly seen in clinical practice, and the prognosis is often poor. Therefore, the determination of immune-related risk scores and immune-related targets for predicting prognoses in patients with LGG is crucial. A single-sample gene set enrichment analysis (ssGSEA) was performed on 22 immune gene sets to calculate immune-based prognostic scores. The prognostic value of the 22 immune cells for predicting overall survival (OS) was assessed using the least absolute shrinkage and selection operator (LASSO) and univariate and multivariate Cox analyses. Subsequently, we constructed a validated effector T-cell risk score (TCRS) to identify the immune subtypes and inflammatory immune features of LGG patients. We divided an LGG patient into a high-risk-score group and a low-risk-score group based on the optimal cutoff value. Kaplan-Meier survival curve showed that patients in the low-risk-score group had higher OS. We then identified the differentially expressed genes (DEGs) between the high-risk-score group and low-risk-score group and obtained 799 upregulated genes and 348 downregulated genes. The analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) show that DEGs were mainly concentrated in immune-related processes. In order to further explore the immune-related genes related to prognosis, we constructed a protein-protein interaction (PPI) network using Cytoscape and then identified the 50 most crucial genes. Subsequently, nine DEGs were found to be significantly associated with OS based on univariate and multivariate Cox analyses. It was further confirmed that CD2, SPN, IL18, PTPRC, GZMA, and TLR7 were independent prognostic factors for LGG through batch survival analysis and a nomogram prediction model. In addition, we used an RT-qPCR assay to validate the bioinformatics results. The results showed that CD2, SPN, IL18, PTPRC, GZMA, and TLR7 were highly expressed in LGG. Our study can provide a reference value for the prediction of prognosis in LGG patients and may help in the clinical development of effective therapeutic agents.

Cholesterol and Phospholipid-free Multilamellar Niosomes Regulate Transdermal Permeation of a Hydrophobic Agent Potentially Administrated for Treating Diseases in Deep Hair Follicles.

We designed cholesterol- and phospholipid-free multilamellar niosomes (MLNs) structured by glyceryl monooleate (GMO) and poloxamer 407 (F127), and evaluated their capacity for transdermal drug delivery. The optimized MLNs had a mean size of 97.88 ± 63.25 nm and an encapsulation efficiency of 82.68% ± 2.14%. The MLNs exhibited a remarkable sustained cargo release, and improved the permeation of the stratum corneum. Compared with the tincture, lower transdermal flux but higher skin deposition of aconitine in vitro were achieved in the MLN group (p < 0.05). Additionally, both water-soluble rhodamine B- and liposoluble coumarin 6-labeled MLNs were found to penetrate deeply into the skin through the hair follicles and could be internalized by fibroblasts Notably, the MLNs possessed greater wettability, and the study focused on delivery to deeper hair follicles and up to the outer hair sheath, which showed advantages for treating diseases of hair follicles, and was potentially superior to the hydrophobic PLGA nanoparticles (diameter: 637.87 ± 22.77 nm) which mainly accumulated in superficial hair follicles. Hair follicles were therefore demonstrated to be an important way to enhance skin permeability, and MLNs are a promising alternative for topical and transdermal drug delivery.

Engineering of Reductive Aminases for Asymmetric Synthesis of Enantiopure Rasagiline.

Reductive aminases (RedAms) for the stereoselective amination of ketones represent an environmentally benign and economically viable alternative to transition metal-catalyzed asymmetric chemical synthesis. Here, we report two RedAms from Aspergillus calidoustus (AcRedAm) and bacteria (BaRedAm) with NADPH-dependent features. The enzymes can synthesize a set of secondary amines using a broad range of ketone and amine substrates with up to 97% conversion. To synthesize the pharmaceutical ingredient (R)-rasagiline, we engineered AcRedAm through rational design to obtain highly stereoselective mutants. The best mutant Q237A from AcRedAm could synthesize (R)-rasagiline with >99% enantiomeric excess with moderate conversion. The features of AcRedAm and BaRedAm highlight their potential for further study and expand the biocatalytic toolbox for industrial applications.

Nano-delivery systems focused on tumor microenvironment regulation and biomimetic strategies for treatment of breast cancer metastasis.

Breast cancer metastasis and recurrence accounts for vast majority of breast cancer-induced mortality. Tumor microenvironment (TME) plays an important role at each step of metastasis, evasion of immunosurveillance, and therapeutic resistance. Consequently, TME-targeting alternatives to traditional therapies focused on breast cancer cells are gaining increasing attention. These new therapies involve the use of tumor cells, and key TME components or secreted bioactive molecules as therapeutic targets, alone or in combination. Recently, TME-related nanoparticles have been developed to deliver various agents, such as bioactive ingredients extracted from natural sources or chemotherapeutic agents, genes, proteins, small interfering RNAs, and vaccines; they have shown great therapeutic potential against breast cancer metastasis. Among various types of nanoparticles, biomimetic nanovesicles are a promising means of addressing the limitations of conventional nanocarriers. This review highlights various nanoparticles related to or mediated by TME according to the key TME components responsible for metastasis. Furthermore, TME-related biomimetic nanoparticles against breast cancer metastasis have garnered attention owing to their promising efficiency, especially in payload delivery and therapeutic action. Here, we summarize recent representative studies on nanoparticles related to cancer-associated fibroblasts, extracellular matrix, endothelial cells, angiogenesis, and immune cells, as well as advanced biomimetic nanoparticles. Future challenges and opportunities in the field are also discussed.

Microneedle-Mediated Biomimetic Cyclodextrin Metal Organic Frameworks for Active Targeting and Treatment of Hypertrophic Scars.

Due to the lack of a delivery system that actively targets hypertrophic scar fibroblasts (HSFs), it is difficult to concentrate the effects of drugs on hypertrophic scars (HSs). We recently discovered that the HSF membrane has a homologous targeting effect and developed an active targeted drug delivery system for the local treatment of HSs. A diphenyl carbonate cross-linked cyclodextrin metal organic framework (CDF) containing more than 26% (w/w) quercetin (QUE) was coated with a HSF membrane (QUE@HSF/CDF) and then dispersed in Bletilla striata polysaccharide (BSP)-fabricated dissolvable microneedles (BSP-MNs-QUE@HSF/CDF) for local administration. This biomimetic nanodrug delivery system improved efficacy on HSs by regulating Wnt/ß-catenin and JAK2/STAT3 pathways and reducing the expression of collagens I and III in HS, and this performance was superior to those of systems without HSF functionalization or the assistance of microneedles. Additionally, we found that BSP has synergistic effects and the microneedles have higher mechanical strength and better physical stability than microneedles made of hyaluronic acid. This currently designed drug delivery strategy integrating biomimetic nanoparticles and dissolvable microneedles is promising for applications in the fields of skin disease treatment and cosmetics.

Symptomatic Infection is Associated with Prolonged Duration of Viral Shedding in Mild Coronavirus Disease 2019: A Retrospective Study of 110 Children in Wuhan.

BACKGROUND: Information regarding viral shedding in children with coronavirus disease 2019 (COVID-19) was limited. This study aims to investigate the clinical and laboratory characteristics associated with viral shedding in children with mild COVID-19. METHODS: The clinical and laboratory information of 110 children with COVID-19 at Wuhan Children's Hospital, Wuhan, China, from January 30 to March 10, 2020, were analyzed retrospectively. RESULTS: The median age was 6 years old. The median period of viral shedding of COVID-19 was 15 days (interquartile range [IQR], 11-20 days) as measured from illness onset to discharge. This period was shorter in asymptomatic patients (26.4%) compared with symptomatic patients (73.6%) (11 days vs. 17 days). Multivariable regression analysis showed increased odds of symptomatic infection was associated with age <6 years (odds ratio [OR] 8.94, 95% confidence interval [CI]: 2.55-31.35; P = 0.001), hypersensitive C-reactive protein >3.0 mg/L (OR 4.89; 95% CI: 1.10-21.75; P = 0.037) and presenting pneumonia in chest radiologic findings (OR 8.45; 95% CI: 2.69-26.61; P < 0.001). Kaplan-Meier analysis displayed symptomatic infection (P < 0.001), fever (P = 0.006), pneumonia (P = 0.003) and lymphocyte counts <2.0 × 10/L (P = 0.008) in children with COVID-19 were associated with prolonged duration of viral shedding in children with COVID-19. CONCLUSION: Prolonged duration of viral shedding in children with COVID-19 was associated with symptomatic infection, fever, pneumonia and lymphocyte count less than 2.0 × 10/L. Monitoring of symptoms could help to know the viral shedding in children with COVID-19.

Activation of a gamma-cyclodextrin-based metal-organic framework using supercritical carbon dioxide for high-efficient delivery of honokiol.

A facile method for the activation of γ-cyclodextrin metal-organic framework (CD-MOF) without channel blockage and framework collapse was first developed using supercritical carbon dioxide (scCO2), which enabled higher surface area and larger pore volume. The scCO2-assisted impregnation method was also applied to introduce the insoluble drug, honokiol (HNK), into the pores of CD-MOF with higher cargo loading compared to the conventional liquid phase incorporation in ethanol. Notably, the resulting HNK-loaded CD-MOF (HNK@CD-MOF) had improved apparent solubility and enhanced dissolution rate. The intestinal cellular uptake and transport experiments demonstrated that CD-MOF could enhance cellular uptake and increase drug transport across the intestinal epithelial cells compared to the cyclodextrin inclusion complex. Moreover, the in vivo pharmacokinetic studies further confirmed that CD-MOF could significantly improve the oral absorption and bioavailability of HNK. Overall, the scCO2 activation and scCO2-assisted impregnation approaches were demonstrated as promising strategies to maximize the potential capability of CD-MOF.

Recent progress in the synthesis, structural diversity and emerging applications of cyclodextrin-based metal-organic frameworks.

Inorganic-organic hybrid materials, especially metal-organic frameworks (MOFs) composed of metals and organic linkers, have emerged as a new class of versatile materials owing to their tunable structure and controllable functionality. As typical biocompatible MOFs, cyclic oligosaccharide cyclodextrin-based carbohydrate metal-organic frameworks (CD-MOFs) have recently attracted considerable attention due to their edible, renewable and biodegradable nature. Herein, we focus on the latest advances concerning these materials. First, the synthesis methods and structural diversity of CD-MOFs are introduced and summarized. Besides, the synthetic strategies of moisture-resistant CD-MOFs are also emphasized. Moreover, their applications, including gas adsorption, separation, sensing, memristor fabrication, as templates in nanoparticle synthesis, light emission and especially drug delivery, are systematically discussed and highlighted. Finally, to conclude the review, some insights and current challenges that need to be addressed for the further development of these materials are proposed. We anticipate that this review will result in a better understanding of CD-MOFs and will help maximize the potential functions of these materials.

Improved self-assembled micelles based on supercritical fluid technology as a novel oral delivery system for enhancing germacrone oral bioavailability.

The main objective of this study was to develop a novel self-assembled micelle system to improve the oral bioavailability of the water-insoluble and thermal instable germacrone (GEM). Micelles were prepared with an improved supercritical reverse phase evaporation (ISCRPE) method, and the thin-film hydration (TFH) method was used for comparison. Physicochemical characterization confirmed the nanospherical morphology of the micelles prepared by the ISCRPE method (GEM@SDL-SCF Micelles) had smaller particle size and greater encapsulation efficiency than that of the micelles prepared by the TFH method (GEM@SDL-THF Micelles). Dilution resistance and stability experiments were performed to assess the structural integrity. In vitro GEM release was analyzed by the dialysis diffusion method, and the micelle system showed sustained and cumulative release. Furthermore, the fluorescence results from the cellular uptake study revealed improved drug absorption of GEM since the green fluorescence intensity of C6@SDL-SCF Micelles were stronger than that of C6@SDL-TFH Micelles. The transcellular transport study showed a distinct increase in the apparent permeability coefficient (AP → BL) in a Caco-2 cell transport model, and free GEM solution, GEM@SDL-TFH Micelles and GEM@SDL-SCF Micelles had permeability coefficients of 7.30 × 10-6, 8.01 × 10-6, and 10.57 × 10-6 cm·s-1, respectively. The pharmacokinetics study in Sprague-Dawley rats showed that the oral absorption capacity of the GEM@SDL-SCF Micelles was obviously enhanced, with a relative oral bioavailability of 298% and 147% compared with that of free GEM solution and GEM@SDL-TFH Micelles, respectively. The gastrointestinal safety assessment demonstrated that the micelles used in the experiment did not cause gastrointestinal toxicity. These results indicated that self-assembled micelles are promising nanocarriers aimed at enhancing the oral absorption of drugs with thermal sensitivity and low aqueous solubility, and micelles prepared by supercritical fluid (SCF) technology showed better performance than those prepared by the TFH method.