PEGylation improves pharmacokinetic profile, liver uptake and efficacy of Interferon gamma in liver fibrosis

Interferon gamma (IFNγ) is a potent cytokine that displays a variety of anti-viral, anti-proliferative, immunomodulatory, apoptotic and anti-fibrotic functions. However, its clinical use is limited to the treatment of few diseases due to the rapid clearance from the body. PEGylated IFN-alpha formulations are shown to be beneficial in viral hepatitis, but PEGylation of IFNγ to enhance its therapeutic effects in liver fibrosis is not yet explored. Liver fibrosis is characterized by the extensive accumulation of an abnormal extracellular matrix and is the major cause of liver-related morbidity and mortality worldwide. To date, there is no pharmacotherapy available for this disease. We modified IFNγ with different-sized linear PEG molecules (5, 10 and 20 kDa) and assessed the biological activity in vitro and in vivo. All PEGylated IFNγ constructs were biologically active and activated IFNγ signaling in vitro as determined with a nitric oxide release assay and a pGAS-Luc reporter plasmid assay, respectively. Similar to IFNγ, all PEGylated IFNγ induced a significant reduction of fibrotic parameters in mouse NIH3T3 fibroblasts as shown with immunohistochemical staining and quantitative PCR analyses. In vivo, the pharmacokinetic profile of radiolabeled ¹²⁵I-IFNγ-PEG conjugates revealed a decreased renal clearance and an increased plasma half-life with an increase of PEG size. Moreover, the liver accumulation of PEGylated IFNγ constructs was significantly higher than the unmodified IFNγ, which was also confirmed by increased MHC-II expression in the livers. Furthermore, in a CCl₄-induced acute liver injury model in mice, PEGylated constructs reduced the early fibrotic parameters more drastically than unmodified IFNγ. Of note, these effects were stronger with higher PEG-sized IFNγ constructs. These data nicely correlated with the pharmacokinetic data. In conclusion, PEGylation significantly improved the pharmacokinetics, liver uptake and anti-fibrotic effects of IFNγ. This study opens new opportunities to exploit the therapeutic applications of PEGylated IFNγ for the treatment of liver fibrosis and other diseases.     

Polyethylene glycol enhances colonic barrier function and ameliorates experimental colitis in rats

Objective Polyethylene glycol (PEG) has been suggested to protect against pathogen colonization by improving colonic barrier function. We aimed to establish whether PEG 4000 affects colonic barrier function and the development of colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) in rats. Materials and methods PEG was included in the drinking water for a period of 48 h before intracolonic administration of TNBS. Results and discussion PEG increased colonic surface hydrophobicity and diminished luminal bacterial load. Moreover, PEG markedly reduced mucosal damage and inflammation induced by TNBS. This protection effect appeared to be independent of its laxative properties since the laxatives mannitol or senna extracts had no effect on TNBS colitis. Using everted colonic sacs, pretreatment with PEG produced a lasting reduction in epithelial permeability to mannitol and dextran-70 K that correlated with decreased surface hydrophobicity. Conclusion Our results suggest that the protective effect of PEG on TNBS colitis is associated with reinforcement of the epithelial barrier. Sebastián Videla and Aurelia Lugea contributed equally to this study.     

Systematic review of stimulant and nonstimulant laxatives for the treatment of functional constipation

BACKGROUND:

Constipation is an uncomfortable and common condition that affects many, irrespective of age. Since 1500 BC and before, health care practitioners have provided treatments and prevention strategies to patients for chronic constipation despite the significant variation in both medical and personal perceptions of the condition.

OBJECTIVE:

To review relevant research evidence from clinical studies investigating the efficacy and safety of commercially available pharmacological laxatives in Canada, with emphasis on studies adopting the Rome criteria for defining functional constipation.

SEARCH METHODS:

PubMed, Medline, Embase and Evidence-Based Medicine Reviews databases were searched for blinded or randomized clinical trials and meta-analyses assessing the efficacy of nonstimulant and stimulant laxatives for the treatment of functional constipation.

RESULTS:

A total of 19 clinical studies and four meta-analyses were retrieved and abstracted regarding study design, participants, interventions and outcomes. The majority of studies focused on polyethylene glycol compared with placebo. Both nonstimulant and stimulant laxatives provided better relief of constipation symptoms than placebo according to both objective and subjective measures. Only one study compared the efficacy of a nonstimulant versus a stimulant laxative, while only two reported changes in quality of life. All studies reported minor side effects due to laxative use, regardless of treatment duration, which ranged from one week to one year. Laxatives were well tolerated by both adults and children.     

Current treatment options and response rates in children with chronic hepatitis C

Vertical transmission has become the most common mode of transmission of hepatitis C virus (HCV) in children.The rate of perinatal transmission from an HCVinfected mother to her child ranges from 2% to 5% and the prevalence of HCV in children in developed countries ranges between 0.1% and 0.4%.Spontaneous viral clearance seems to be dependent on the genotype and has been reported between 2.4%-25%.For chronically infected patients,treatment with recombinant polyethylene glycol (PEG)-interferon α-2b and daily ribavirin has now been approved as standard treatment for children 2-17 years of age.In five large prospective studies,a total of 318 children and adolescents aged 3-17 years were treated either with subcutaneous PEG-interferon α-2b at a dose of 1-1.5 μg/kg or 60 μg/m2 once a week in combination with oral ribavirin (15 mg/kg per day) or PEG-interferon α-2a with ribavirin.Subjects with genotype 1 and 4 received the medication for 48 wk and individuals with genotype 2 and 3 mainly for 24 wk.Overall sustained viral response (SVR) was achieved in 193/318 (60.7%) of treated patients.Stratified for genotype;120/234 (51%) with genotype 1,68/73 (93%) with genotype 2/3,and 6/11 (55%) with genotype 4 showed SVR.Relapse rate was between 7.7% and 17%.Overall,treatment was well tolerated;how-ever,notable side effects were present in approximately 20%.According to recent experiences in the treatment of chronic hepatitis C in children and adolescents,a combination of PEG-interferon α with ribavirin has been found to be well tolerated and highly efficacious,particularly in individuals with genotype 2/3.Thus,this treatment can be recommended as standard of care until more effective treatment options will become available for genotype 1 patients.     

血液粘度质控物的研究与应用

目的：研制一种测定血液粘度的质控液，以确保标本测定结果的准确可靠。方法：分别制备200g/L、150g/L、100g/L的聚乙二醇6000溶液作为测定全血粘度的高、中、低的质控液。结果：高、中、低质控液在切变率(150s^-1、60s^-1、10s^-1)的批内精密度分别为（2．85％、1．20％、0．89％）、（1．61％、0．57％、0．42％）、（2．93％、1．95％、1．63％），高、中、低质控液在切变率150s^-1的日间精密度为1．11％、1．16％、2．12％。结论：聚乙二醇6000溶液具有牛顿液体的特征，性质稳定，水溶性好，是测定全血粘度的良好质控液。     

聚乙二醇电解质散在结肠镜检查前肠道准备中的应用

目的 :探讨聚乙二醇电解质散在结肠镜检查前肠道准备中的效果和安全性。方法 :4 4例接受结肠镜检查的病人随机分为A组和B组 ,A组口服聚乙二醇电解质散 ,B组口服Niflec。观察服药过程中排便情况 ,肠腔清洗效果和气泡存在情况。服药前和结肠镜检查结束后分别进行血尿常规、肝肾功能检查和电解质测定。结果 :两组病人在服药后约 1～ 1.5h开始排便 ,排便 3～ 5次后即可接受肠镜检查 ,清洁肠道的有效率均为10 0 % ,无 1例出现恶心、呕吐、腹痛和头痛等不良反应。两组在排便时间 ,肠腔清洗效果和实验室指标变化间比较均无显著差异。结论 :聚乙二醇电解质散应用于结肠镜检查前的肠道准备安全有效 ,准备时间短 ,不需要饮食限制 ,值得临床推广应用     

A low-volume polyethylene glycol plus ascorbate solution for bowel cleansing prior to colonoscopy: The NORMO randomised clinical trial

Background

Patient acceptability of the preparation is a key factor in the success of colonoscopy, yet standard polyethylene glycol solutions are poorly tolerated owing to their high volume (4 L) and low palatability. This study compared the efficacy, safety and acceptability of a 2 L polyethylene glycol + ascorbate solution with a standard 4-L polyethylene glycol solution.

Methods

Adults referred for colonoscopy were randomised to 2-L polyethylene glycol + ascorbate (n = 202) or 4-L polyethylene glycol solution (n = 198). Colon cleansing success was assessed using the Harefield Cleansing Scale^© and the Aronchick scale. Safety and acceptability were also assessed.

Results

Successful cleansing was achieved in 94.1% and 90.9% of subjects with the 2-L and 4-L solutions respectively using the Harefield Cleansing Scale^© and 94.6% and 90.0% using the Aronchick scale (non significant). Despite better acceptability and tolerability, no superiority over the standard 4-L preparation was demonstrated. Fewer treatment-related adverse events were reported with the 2-L solution (80.2% versus 89.9%, p = 0.011). More subjects were willing to take the 2 L PEG + ascorbate solution again (87% versus 51%, p < 0.001), found it easier to drink (80% versus 70%, p = 0.025), with a better taste (p = 0.01).

Conclusions

Two-litre polyethylene glycol + ascorbate solution, with a similar high degree of cleansing and superior acceptability and tolerability, presents an alternative to 4-L polyethylene glycol when compliance is an issue.     

Molecular weight dependence of polyethylene glycol penetration across acetone-disrupted permeability barrier

Abstract Previous studies have demonstrated that permeability barrier disruption by acetone treatment significantly enhances skin permeability to both hydrophilic and amphipathic compounds, but not to highly lipophilic compounds. The purpose of the present study was to investigate the dependence of permeability on molecular weight (MW) in acetone-disrupted hairless mouse skin in contrast to normal skin. Penetration of polyethylene glycol (PEG) 300, 600, and 1000 over 12 h was measured using diffusion cells. High-performance liquid chromatographic methods with refractive index detection were used to separate and quantitate the individual oligomeric species in the PEG samples. Percutaneous penetration of PEGs exhibited slightly steeper MW dependency at a transepidermal water loss (TEWL) of 30–41 g/m² per h in comparison with TEWLs of 0–10 (control skin), 10–20, and 20–30 g/m² per h, with a higher percentage of smaller oligomer PEGs penetrating than larger ones. Increasing the TEWL of the skin increased the penetration of all the PEG oligomers, and the degree of the enhancement relative to penetration through control skin increased with MW and was maximal for oligomers with a MW ranging from 326 to 414 Da. Within the limit of quantitation of the assay, the MW cut-off for PEG penetration across mouse skin with TEWLs of 0–10, 10–20, and 20–30 g/m² per h was 414, 590, and 942 Da, respectively, while all the measurable oligomers up to MW 1074 Da were able to penetrate skin with TEWLs in the range 30–41 g/m² per h. The results suggest that not only higher amounts but also more varieties of chemicals may penetrate skin with a compromised barrier than normal skin, implying a higher risk of intoxication and hypersensitization by environmental agents through diseased skin with impaired barrier function. Received: 24 October 2000 / Revised: 20 January 2001 / Accepted: 3 March 2001     

Hypersensitivity reactions to anti-SARS-CoV-2 vaccines: Basophil reactivity to excipients

Basophil activation test (BAT) can tackle multiple mechanisms underlying acute and delayed hypersensitivity to drugs and vaccines and might complement conventional allergy diagnostics but its role in anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine-related hypersensitivity is ill-defined. Therefore, 89 patients with possible hypersensitivity (56 % with delayed mucocutaneous manifestations) to anti-SARS-CoV-2 vaccines were tested with BAT for Macrogol 3350, DMG-PEG 2000, PEG 20000, polysorbate-80 and trometamol and compared to 156 subjects undergoing pre-vaccine BAT. A positive BAT was associated with delayed reaction onset (p = 0.010) and resolution (p = 0.011). BAT was more frequently positive to DMG-PEG 2000 than to other excipients in both groups (p < 0.001). DMG-PEG 2000 reactivity was less frequent in vaccine-naïve (6 %) than vaccinated subjects (35 %, p < 0.001) and associated with mRNA-1273 vaccination. DMG-PEG 2000 BAT might therefore have a diagnostic role in subjects with delayed hypersensitivity reactions. Natural immunity might be a key player in basophil activation.