Galacturonic acid-capsaicin prodrug for prolonged nociceptive-selective nerve blockade.

There is an urgent clinical need to develop nerve-blocking agents capable of inducing long duration sensory block without muscle weakness or paralysis to treat post-operative and chronic pain conditions. Here, we report a galacturonic acid-capsaicin (GalA-CAP) prodrug as an effective nociceptive-selective axon blocking agent. Capsaicin selectively acts on nociceptive signaling without motor nerve blockade or disruption of proprioception and touch sensation, and the galacturonic acid moiety enhance prodrug permeability across the restrictive peripheral nerve barriers (PNBs) via carrier-mediated transport by the facilitative glucose transporters (GLUTs). In addition, following prodrug transport across PNBs, the inactive prodrug is converted to active capsaicin through linker hydrolysis, leading to sustained drug release. A single injection of GalA-CAP prodrug at the sciatic nerves of rats led to nociceptive-selective nerve blockade lasting for 234 ± 37 h, which is a sufficient duration to address the most intense period of postsurgical pain. Furthermore, the prodrug markedly mitigated capsaicin-associated side effects, leading to a notable decrease in systemic toxicity, benign local tissue reactions, and diminished burning and irritant effects.

Hydration-induced Void-containing Hydrogels for Encapsulation and Sustained Release of Small Hydrophilic Molecules.

Efficient encapsulation and sustained release of small hydrophilic molecules from traditional hydrogel systems have been challenging due to the large mesh size of 3D networks and high water content. Furthermore, the encapsulated molecules are prone to early release from the hydrogel prior to use, resulting in a short shelf life of the formulation. Here, we present a hydration-induced void-containing hydrogel (HVH) based on hyperbranched polyglycerol-poly(propylene oxide)-hyperbranched polyglycerol (HPG-PPG-HPG) as a robust and efficient delivery system for small hydrophilic molecules. Specifically, after the HPG-PPG-HPG is incubated overnight at 4 °C in the drug solution, it is hydrated into a hydrogel containing micron-sized voids, which could encapsulate hydrophilic drugs and achieve 100% drug encapsulation efficiency. In addition, the voids are surrounded by a densely packed polymer matrix, which restricts drug transport to achieve sustained drug release. The hydrogel/drug formulation can be stored for several months without changing the drug encapsulation and release properties. HVH hydrogels are injectable due to shear thinning properties. In rats, a single injection of the HPG-PPG-HPG hydrogel containing 8 µg of tetrodotoxin (TTX) produced sciatic nerve block lasting up to 10 hours without any TTX-related systemic toxicity nor local toxicity to nerves and muscles.

Cerebral Abscess Infected by Nocardia gipuzkoensis.

Purpose: Nocardia gipuzkoensis is a novel species that solely identified in patients with pulmonary infections by far. Growing evidence showed the excellent performance of metagenomics next-generation sequencing (mNGS) on pathogenic identification, especially for new species. Here, we described the first case of an elderly female patient suddenly suffering from neurological disorders owing to N. gipuzkoensis infection. And linezolid could effectively treat N. gipuzkoensis infection. Patients and Methods: The results of imaging, laboratory cultures, and mNGS, as well as therapeutic process are shared. Results: An elderly female patient suddenly suffered from neurological disorders with dysphasia and right limb trembles under no obvious causes. Subsequently, she was diagnosed as intracranial space-occupying lesions by magnetic resonance imaging (MRI). The isolate from brain secretion was further identified as N. gipuzkoensis through mNGS. The targeted therapy with linezolid according to the antimicrobial susceptibility was used to treat cerebral abscess induced by N. gipuzkoensis. During the follow-up, no relapse was observed for the patient after surgery for 104 days. Conclusion: Cerebral abscess induced by N. gipuzkoensis is rare disorder with high mortality. mNGS has been identified as a promising tool in pathogen diagnosis for timely therapy. Linezolid as one of the antimicrobial drugs could effectively treat N. gipuzkoensis infection and prevent adverse outcomes.

Outbreak of OXA-232-producing carbapenem-resistant Klebsiella pneumoniae ST15 in a Chinese teaching hospital: a molecular epidemiological study.

Background and Aims: The incidence of OXA-232-producing carbapenem-resistant Klebsiella pneumoniae (CRKP) has been on the rise in China over the past five years, potentially leading to nosocomial epidemics. This study investigates the first outbreak of CRKP in the Second Affiliated Hospital of Jiaxing University. Methods: Between February 2021 and March 2022, 21 clinical isolates of OXA-232-producing CRKP were recovered from 16 patients in the Second Affiliated Hospital of Jiaxing University. We conducted antimicrobial susceptibility tests, whole genome sequencing, and bioinformatics to determine the drug resistance profile of these clinical isolates. Results: Whole-genome sequencing revealed that all 21 OXA-232-producing CRKP strains belonged to the sequence type 15 (ST15) and shared similar resistance, virulence genes, and plasmid types, suggesting clonal transmission between the environment and patients. Integrated genomic and epidemiological analysis traced the outbreak to two clonal transmission clusters, cluster 1 and cluster 2, including 14 and 2 patients. It was speculated that the CRKP transmission mainly occurred in the ICU, followed by brain surgery, neurosurgery, and rehabilitation department. Phylogenetic analysis indicated that the earliest outbreak might have started at least a year before the admission of the index patient, and these strains were closely related to those previously isolated from two major adjacent cities, Shanghai and Hangzhou. Comparative genomics showed that the IncFII-type and IncHI1B-type plasmids of cluster 2 had homologous recombination at the insertion sequence sites compared with the same type of plasmids in cluster 1, resulting in the insertion of 4 new drug resistance genes, including TEM-1, APH(6)-Id, APH(3'')-Ib and sul2. Conclusions: Our study observed the clonal spread of ST15 OXA-232-producing between patients and the hospital environment. The integration of genomic and epidemiological data offers valuable insights and facilitate the control of nosocomial transmission.

Drug Permeability: From the Blood-Brain Barrier to the Peripheral Nerve Barriers.

Drug delivery into the peripheral nerves and nerve roots has important implications for effective local anesthesia and treatment of peripheral neuropathies and chronic neuropathic pain. Similar to drugs that need to cross the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB) to gain access to the central nervous system (CNS), drugs must cross the peripheral nerve barriers (PNB), formed by the perineurium and blood-nerve barrier (BNB) to modulate peripheral axons. Despite significant progress made to develop effective strategies to enhance BBB permeability in therapeutic drug design, efforts to enhance drug permeability and retention in peripheral nerves and nerve roots are relatively understudied. Guided by knowledge describing structural, molecular and functional similarities between restrictive neural barriers in the CNS and peripheral nervous system (PNS), we hypothesize that certain CNS drug delivery strategies are adaptable for peripheral nerve drug delivery. In this review, we describe the molecular, structural and functional similarities and differences between the BBB and PNB, summarize and compare existing CNS and peripheral nerve drug delivery strategies, and discuss the potential application of selected CNS delivery strategies to improve efficacious drug entry for peripheral nerve disorders.

Corrigendum: Effects of Poria cocos extract on metabolic dysfunction-associated fatty liver disease via the FXR/PPARα-SREBPs pathway.

[This corrects the article DOI: 10.3389/fphar.2022.1007274.].

Case report: A clinical case study of six patients with Chlamydia psittaci pneumonia.

Objective: To investigate the clinical features, diagnosis, and treatment of Chlamydia psittaci (C. psittaci) pneumonia. Methods: We retrospectively analyzed the clinical data of six patients with C. psittaci pneumonia who were admitted to the Division of Pulmonary and Critical Care Medicine of the Second Hospital of Jiaxing from December 2021 to September 2022. Results: All patients reported a fever and other accompanying symptoms, including cough (5/6), chest tightness (1/6), fatigue (2/6), and headache (1/6). Laboratory results showed that all patients had high levels of C-reactive protein (CRP≥70 mg/L), procalcitonin (PCT; 2 patients with PCT levels ≥0.5 ng/L), and erythrocyte sedimentation rate (ESR). Lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) levels were elevated in 3/6 and of 2/6 patients, respectively. Chest computed tomography (CT) of most patients showed patchy, high-density shadows with partial consolidation, accompanied by air bronchogram signs and pleural effusion. Six patients were diagnosed with C. psittaci pneumonia using metagenomic next-generation sequencing (mNGS). They showed favorable outcomes following immediate adjustment of the regimen to doxycycline-based therapy and hydration, nutrition, and other follow-up treatments. In the imaging findings obtained at one-two month, the lesions were completely cleared, suggesting a favorable prognosis. Conclusion: Patients with C. psittaci pneumonia commonly present sepsis and rapidly progressing disease. Early diagnosis is critical for C. psittaci pneumonia using mNGS, which can lead to favorable prognoses via immediate adjustment therapies.

Emulsion-induced polymersomes taming tetrodotoxin for prolonged duration local anesthesia.

Injectable local anesthetics that can provide a continuous nerve block approximating the duration of a pain state would be a life-changing solution for patients experiencing post-operative pain or chronic pain. Tetrodotoxin (TTX) is a site 1 sodium channel blocker that is extremely potent compared to clinically used local anesthetics. Challengingly, TTX doses are limited by its associated systemic toxicity, thus shortening the achievable duration of nerve blocks. Here, we explore emulsion-induced polymersomes (EIP) as a drug delivery system to safely use TTX for local anesthesia. By emulsifying hyperbranched polyglycerol-poly (propylene glycol)-hyperbranched polyglycerol (HPG-PPG-HPG) in TTX aqueous solution, HPG-PPG-HPG self-assembled into micrometer-sized polymersomes within seconds. The formed polymersomes have microscopically visible internal aqueous pockets that encapsulate TTX with an encapsulation efficiency of up to 94%. Moreover, the polymersomes are structurally stable, enabling sustained TTX release. In vivo, the freshly prepared EIP/TTX formulation can be directly injected and increased the tolerated dose of TTX in Sprague-Dawley rats to 11.5 µg without causing any TTX-related systemic toxicity. In the presence of the chemical penetration enhancer (CPE) sodium octyl sulfate (SOS), a single perineural injection of EIP/TTX/SOS formulation produced a reliable sciatic nerve block for 22 days with minimal local toxicity.

Effects of Poria cocos extract on metabolic dysfunction-associated fatty liver disease via the FXR/PPARα-SREBPs pathway.

Despite the increase in the global prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD), no approved drug currently exists for the disease. Poria cocos (Schw.) Wolf (P. cocos) is a medicinal mushroom belonging to a family of polyporaceae widely used in TCM clinics to protect the liver and treat obesity. However, its efficacy, practical components, and underlying mechanism against MAFLD are yet to be determined. In this study, we evaluated the effects of Poria cocos (P. cocos) ethanol extract (EPC) on hepatic dyslipidemia, steatosis, and inflammation by both bioinformatics analysis and MAFLD rats induced by HFD feeding. We found EPC treatment dramatically reduced lipid accumulation, inflammatory cell infiltration, and liver injury. EPC reduced serum TC, TG levels, and hepatic TG, TBA, and NEFA contents. UHPLC Q-Trap/MS examination of BA profiles in serum and feces showed that EPC increased fecal conjugated BAs, decreased free BAs, and improved BA metabolism in HFD-fed rats. Western blot and RT-qPCR analysis showed that EPC could activate hepatic FXR and PPARα expression and reduce CYP7A1 and SREBP-1c expression. Systemic pharmacology combined with molecular docking suggested that poricoic acid B and polyporenic acid C, the major active compounds in EPC, could ameliorate lipid homeostasis by activating the nuclear receptor PPARα. We further confirmed their inhibition effects of lipid droplet deposition in steatized L-02 hepatocytes. In summary, EPC alleviated HFD-induced MAFLD by regulating lipid homeostasis and BA metabolism via the FXR/PPARα-SREBPs signaling pathway. P. cocos triterpenes, such as poricoic acid B and polyporenic acid C, were the characteristic substances of P. cocos for the treatment of MAFLD.

Jian Pi Shen Shi formula alleviates hyperuricemia and related renal fibrosis in uricase-deficient rats via suppression of the collagen-binding pathway.

AIM: Jian Pi Shen Shi Formula (JPSSF) is a beneficial treatment for hyperuricemia and related tissue damage in the clinical setting. This study was designed to investigate its therapeutic potential and underlying mechanisms in uricase-deficient rats (Uox-/- rats). METHODS: Uox-/- rats were used to assess the therapeutic potential of JPSSF on hyperuricemia. Protein extracts from renal tissues of a Uox-/- group and a JPSSF group were analyzed using tandem mass tag labeling quantitative proteomic workflow. Collagen deposition in Uox-/- rat kidneys was analyzed by Masson trichromatic staining. The gene expression associated with collagen-binding-related signaling pathways in the kidneys was further explored using quantitative polymerase chain reaction assay. The protein expressions of collagen 1a1 (col1a1), col6a1, and α-smooth muscle actin were measured by Western blotting and immunohistochemistry. RESULTS: JPSSF significantly decreased renal function indices and alleviated renal injuries. The action of JPSSF was manifested by down-regulation of col6a1 and interleukin-1 receptor-associated kinase-like 2, which blocked the binding sites on collagen and further prevented kidney injury. The anti-renal fibrosis effect of JPSSF was confirmed by reducing the collagen deposition and hydroxyproline concentrations. JPSSF treatment also intensely down-regulated the mRNA and protein expressions of col6a1, col1a1, and α-smooth muscle actin, which inhibited the function of the collagen-binding-related signaling pathway. CONCLUSION: Our results indicated that JPSSF notably ameliorated hyperuricemia and related renal fibrosis in Uox-/- rats through lowering uric acid and down-regulating the function of the collagen-binding pathway. This suggested that JPSSF is a potential empirical formula for treating hyperuricemia and accompanying renal fibrosis.

MW­9, a chalcones derivative bearing heterocyclic moieties, attenuates experimental autoimmune encephalomyelitis via suppressing pathogenic TH17 cells.

Previous studies have indicated that MW­9, a chalcones derivative bearing heterocyclic moieties, has considerable anti­inflammatory activity in vitro. Whether MW­9 may be used to treat inflammation­based diseases, such as multiple sclerosis, remains unknown. The present study was designed to determine the effect and underlying mechanism of MW­9 in experimental autoimmune encephalomyelitis (EAE). Female C57BL/6 mice immunized with MOG35­55 were treated with or without MW­9, then the clinical scores and other relevant parameters were investigated. Production of cytokines and specific antibodies were monitored by ELISA assays. Surface marker, Treg cell, and intracellular cytokines (IL­17A and IFN­Î³) were detected by flow cytometry, and mRNA expression in the helper­T (TH)17 cell­related signaling pathway was examined by reverse transcription­quantitative (RT­q) PCR analysis. TH17 cell differentiation assay was performed. Herein, the present results demonstrated that oral administration of MW­9 reduced the severity of disease in EAE mice through slowing down infiltration process, inhibiting the demyelination, blocking anti­MOG35­55 IgG antibody production (IgG, IgG2a and IgG3), and decreasing accumulation of CD11b+Gr­1+ neutrophils from EAE mice. MW­9 treatments also led to significantly decreased IL­17A production and IL­17 expression in CD4+ T­cells, but had no detectable influence on development of TH1 and T­regulatory cells ex vivo. RT­qPCR analysis showed that within the spinal cords of the mice, MW­9 blocked transcriptional expression of TH17­associated genes, including Il17a, Il17f, Il6 and Ccr6. In TH17 cell differentiation assay, MW­9 inhibited differentiation of 'naïve' CD4+ T­cells into TH17 cells and reduced the IL­17A production. The data demonstrated that MW­9 could attenuate EAE in part through suppressing the formation and activities of pathogenic TH17 cells.

Bioactive Components and Potential Mechanism Prediction of Kui Jie Kang against Ulcerative Colitis via Systematic Pharmacology and UPLC-QE-MS Analysis.

Kui Jie Kang (KJK)-a traditional Chinese medicine-has demonstrated clinical therapeutic efficacy against ulcerative colitis (UC). However, the active compounds and their underlying mechanisms have not yet been fully characterized. Therefore, the current study sought to identify the volatile compounds in KJK responsible for eliciting the therapeutic effect against UC, while also analyzing key targets and potential mechanisms. To this end, systematic network pharmacology analysis was employed to obtain UC targets by using GeneCards, DisGeNET, OMIM, among others. A total of 145 candidate ingredients, 412 potential targets of KJK (12 herbs), and 1605 UC targets were identified. Of these KJK and UC targets, 205 intersected and further identified AKT1, JUN, MAPK, ESR, and TNF as the core targets and the PI3K/AKT signaling pathway as the top enriched pathway. Moreover, molecular docking and ultra-performance liquid chromatography Q Exactive-mass spectrometry analysis identified quercetin, kaempferol, luteolin, wogonin, and nobiletin as the core effective compounds of KJK. In vivo murine studies revealed that KJK exposure increases the body weight and colon length, while reducing colonic epithelial injury, and the expression of inflammatory factors in colitis tissues such as TNF-α, IL-6, and IL-1ß. Furthermore, KJK treatment downregulates the expression of pi3k and akt genes, as well as p-PI3K/PI3K and p-AKT/AKT proteins. Collectively, these findings describe the therapeutic effects and mechanisms of KJK in UC and highlight KJK as a potentially valuable therapeutic option for UC via modulation of the PI3K/AKT signaling pathway, thus providing a theoretical reference for the broader application of KJK in the clinical management of UC.

The discovery of potentially active diterpenoids to inhibit the pyroptosis from Callicarpa arborea.

Pyroptosis is a programmed-inflammatory cell death, which leads to release of inflammatory cellular contents and formation of inflammation. Uncontrollable pyroptosis can result in serious immune diseases, such as cytokine release syndrome (CRS), sepsis, disseminated intravascular coagulation (DIC), and acute organ damage, including acute respiratory distress syndrome (ARDS) and acute kidney injury (AKI). Members of the Callicarpa genus are significant raw materials for traditional Chinese medicine, widely used for analgesia, hemostasis, and anti-inflammation. Previously, we have reported some ent-clerodane diterpenoids from Callicarpa arborea, shown potent inhibitory effects against pyroptosis. In this study, we went on investigating this kind of diterpenoids, and yielded 66 ent-clerodane diterpenoids, including 52 new compounds, from Callicarpa arborea. Their structures featured with a 5/6- (1-25) or a 6/6- (26-66)-fused double-ring scaffolds, were elucidated using spectroscopic data, electrostatic circular dichroism (ECD) and X-ray diffraction analyses. Screening for the inhibitory activity against pyroptosis by detecting of IL-1ß secretion in J771A.1 cells, revealed 28 compounds with an IC50 below 10.5 µM. Compound 1 was the most potent with an IC50 of 0.68 µM and inhibited the J774A.1 macrophage pyroptosis by blocking the NLR pyrin domain containing 3 (NLRP3) inflammasome activation. An in vivo study further revealed that compound 1 decreased infiltration of CD11b + F4/80 + macrophages into lung and attenuated the lipopolysaccharide (LPS)-induced lung injury. Taken together, this study indicated the potential of compound 1 as a candidate for pyroptosis-related inflammation treatment, as well as provided the chemical and pharmacological basis for the further development of Callicarpa genus as a herbal medicine.

Laboratory management for large-scale population screening for SARS-CoV-2.

INTRODUCTION: The aim of this study was to investigate the improvements in laboratory testing procedures and the quality and safety management for large-scale population screening for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: Because of epidemic prevention and control needs in Hebei Province, on January 7, 2021, the Health Commission of Zhejiang Province sent a medical team to Hebei Province, to carry out SARS-CoV-2 nucleic acid testing. Screening for the SARS-CoV-2 nucleic acid test was performed using reverse-transcription polymerase chain reaction (RT-PCR). Practical tests and repeated process optimization were adopted to explore the optimal solution for improving laboratory testing procedures and the quality of and safety management for large-scale population screening for SARS-CoV-2. RESULTS: The Zhejiang medical team completed 250,000 pooled SARS-CoV-2 nucleic acid samples in 24 days in Shijiazhuang, with a peak daily testing capacity of 40,246 samples testing. There were no false-negative or false-positive results, and no laboratory personnel was infected with SARS-CoV-2. Significant achievements have been made in SARS-CoV-2 prevention and control. CONCLUSIONS: This report summarizes the effort of the medical team regarding their management of the quality and safety of laboratory tests and proposes corresponding empirical recommendations to provide a reference for future large-scale population screening SARS-CoV-2.

Inactivated SARS-CoV-2 vaccines elicit immunogenicity and T-cell responses in people living with HIV.

BACKGROUNDS: To date, the effects of SARS-CoV-2 vaccines on people living with HIV (PLWH) were mainly focused on messenger RNA (mRNA) and adenovirus vector-based vaccines, and little is known about the effects of inactivated virus-based vaccine. This study was designed to determine the effects of inactivated SARS-CoV-2 vaccines on PLWH. METHODS: Twenty-four HIV-positive individuals and 24 healthy donors (HD) were respectively recruited from Malipo Country People's Hospital and community in Kunming city. Enumeration of lymphocyte and CD4+CD45RO+ memory T cells were evaluated by flow cytometry. Competitive ELISA was used to measure the level of Anti-SARS-CoV-2 neutralization antibody. Spearman or Pearson correlation analysis was used to analyze the relationship between laboratory indicators and neutralization antibodies in PLWH. T-cell responses (Th1, Th2, Th17, Treg) and intracellular expression of cytokines (IL-2 and TNF-α) in CD4 or CD8 were induced by spike protein in SARS-CoV-2 (SARS-2-S) and further measured by intracellular staining. RESULTS: CD4, B cells, CD4+CD45RO+ memory T cells in peripheral blood of PLWH are dramatically decreased in comparison with HD. Importantly, PLWH display comparable neutralizing antibody positive rate to HD after inoculation with inactivated SARS-CoV-2 vaccine. However, PLWH showed weaker responses to vaccines exhibited by lower levels of neutralizing antibodies. Correlation analysis shows that this is possibly caused by low number of CD4 and B cells. Furthermore, SARS-2-S-induced Th2 and Th17 responses are also decreased in PLWH, while no influences on Treg and other cytokines (IL-2, TNF-α and IFN-γ) observed. CONCLUSIONS: PLWH and HD have comparable neutralizing antibodies positive rates, but PLWH display weaker responses to inactivated SARS-CoV-2 vaccines in magnitude, which suggests that a booster dose or dose adjustment are required for HIV-infected individuals, especially for those with lower counts of CD4 T and B cells.

The Efficacy and Safety of Revefenacin for the Treatment of Chronic Obstructive Pulmonary Disease: A Systematic Review.

Background Revefenacin (REV) is a novel once-daily long-acting muscarinic antagonist (LAMA) in the treatment of moderate to very severe chronic obstructive pulmonary disease (COPD). This systematic review incorporating a dose-response meta-analysis aimed to assess the efficacy and safety of REV. Methods PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, VIP database, and Wanfang database were searched from their inception to April 2020. We included randomized controlled trials (RCTs) which evaluated the efficacy and safety of REV in COPD patients. Two reviewers independently performed study screening, data extraction, and risk of bias assessment. Outcomes consisted of the mean change in trough Forced Expiratory Volume in 1 second (FEV1) from baseline, adverse events (AEs), and serious adverse events (SAEs). A dose-response meta-analysis using the robust error meta-regression method was conducted. We used Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to assess the quality of evidence. Results Nine RCTs (3,121 participants) were included in this systematic review. The meta-analyses indicated that 175 µg/day REV could significantly improve the trough FEV1 (MD=143.67, 95%CI: 129.67 to 157.68; I2=96%; 809 participants; studies=4; low quality) without increasing the risk of AEs (OR=0.98, 95%CI: 0.81 to 1.18; I2=34%; 2,286 participants; studies=7; low quality) or SAEs (OR=0.89, 95%CI: 0.55 to 1.46; I2=0%; 2,318 participants; studies=7; very low quality) compared to placebo. Furthermore, the effect of REV in increasing trough FEV1 was dose-dependent with an effective threshold of 88 µg/day (R2 = 0.7017). Nevertheless, only very low-quality to low-quality evidence showed that REV at a dose of 175 µg/day was inferior to tiotropium regarding the long-term efficacy, and its safety profile was not superior to tiotropium or ipratropium. Conclusion Current evidence shows that REV is a promising option for the treatment of moderate to very severe COPD. Due to most evidence graded as low quality, further studies are required to compare the efficacy, long-term safety and cost-effectiveness between REV and other LAMAs in different populations. Clinical Trial Registration: [PROSPERO], identifier [CRD42020182793].

Applications of capillary action in drug delivery.

Contrary to the fact that capillary action is ubiquitous in our daily lives, its role in drug delivery has not attracted attention. Therefore, its application in medicine and disease treatment has not been actively developed. This perspective begins by reviewing the principles, advantages, and limitations of the three existing drug delivery strategies: non-covalent interaction, cavity loading, and covalent conjugation. Then, we discussed the principle of capillary action in drug delivery and the influencing factors that determine its performance. To illustrate the advantages of capillary action over existing drug delivery strategies and how the capillary action could potentially address the shortcomings of the existing drug delivery strategies, we described five examples of using capillary action to design drug delivery platforms for disease treatment: marker pen for topical and transdermal drug delivery, microneedle patch with a sponge container for pulsatile drug delivery, core-shell scaffold for sustained release of growth factors, oral bolus for insulin delivery to the esophagus, and semi-hollow floating ball for intravesical and gastroprotective drug delivery. Each of the five drug delivery platforms exhibits certain unique functions that existing drug delivery technologies cannot easily achieve, hence expected to solve specific practical medical problems that are not satisfactorily resolved. As people pay more attention to capillary action and develop more drug delivery platforms, more unique functions and characteristics of capillary action in drug delivery will be explored. Thus, capillary action could become an important choice for drug delivery systems to improve therapeutic drug efficacy, treat diseases, and improve human health.

Nanoparticle-mediated surfactant therapy in patients with severe COVID-19: a perspective.

Coronavirus disease 2019 (COVID-19) is an RNA virus-based disease that can be deadly. For critically ill patients, mechanical ventilation is an important life-saving treatment. However, mechanical ventilation shows a trade-off between supporting respiratory function and ventilator-induced lung injury (VILI). Surfactant therapy is a medical administration of exogenous surfactant to supplement or replace deficient or dysfunctional endogenous surfactant. Surfactant therapy can be used to postpone or shorten the use of mechanical ventilation to minimize or avoid VILI, because surfactants can reduce surface tension, improve lung compliance, and enhance oxygenation. In addition, nanotechnology can be applied to improve the therapeutic effect and reduce the adverse effects of surfactants. In this perspective, we discussed how nanoparticles deliver surfactants through intravenous injection and inhalation to the expected lung disease regions where surfactants are mostly needed, and discussed the prospects of nanoparticle-mediated surfactant therapy in the treatment of patients with severe COVID-19.

Zero-Order Controlled Release of Water-Soluble Drugs Using a Marker Pen Platform.

Zero-order drug release that releases drugs at a constant rate is beneficial to prolong the therapeutic effect and avoid the side effects of drugs. However, due to the weak interaction between the drug and the carrier, it is particularly challenging to achieve zero-order release of water-soluble drugs. Inspired by the marker pen, which stores the water-based ink in the sponge core and releases a constant amount of ink from the tip for writing, we explore the marker pen as a drug delivery platform to achieve zero-order release of water-soluble drugs. Through the capillary interaction between the material and water, the pen core can absorb the aqueous drug solution to encapsulate and store the water-soluble drug model sodium fluorescein (SF) and can release the encapsulated SF by moving the pen tip across the surface. The results show that the marker pen can release a constant amount of SF at the nanogram level per unit length of the line drawn with the pen, and the cumulative SF release amount has a linear relationship with the length of the line. In addition, the amount of released SF is linear with respect to the SF concentration in the aqueous solution. Moreover, the SF-filled marker pen has excellent long-term stability as evidenced by that the amount of SF released from the pen remains constant within two weeks after filling.