PEG Group Research Articles

Engineering enzyme conformation within liquid-solid hybrid microreactors for enhanced continuous-flow biocatalysis

The artificial engineering of an enzyme’s structural conformation and dynamic properties to promote its catalytic activity and stability outside cellular environments is highly pursued in industrial biotechnology. Here, we describe an elegant strategy of combining the rationally designed liquid-solid hybrid microreactor with a tailor-made polyethylene glycol functional ionic liquid (PEG-IL) microenvironment to exercise a high level of control over the configuration of enzymes for practical continuous-flow biocatalysis. As exemplified by a lipase driven kinetic resolution reaction, the obtained system exhibits a 2.70 to 30.35-fold activity enhancement compared to their batch or traditional IL-based counterparts. Also, our results demonstrate that the thermal stability of encapsulated lipase can be significantly strengthened in the presence of PEG groups, showcasing a long-term continuous-flow stability even up to 1000 h at evaluated temperature of 60 oC. Through systematic experiment and molecular dynamics simulation studies, the conformational changes of the active site cavity in the modified lipases are correlated with enzymatic properties alteration, and the pronounced effects of PEG-groups in stabilizing enzyme’s secondary structures by delaying unfolding at elevated temperatures are identified. We believe that this study will guide the design of high-performance enzymatic systems, promoting their utilization in real-world biocatalysis applications.

The synergistic potential of polyethylene glycol 400 for the control of Hyphantria cunea larvae by Beauveria bassiana

The efficacy of entomopathogenic fungi as pest control agents is constrained by both their physiological state and external environmental factors. This study identified synergists capable of enhancing the insecticidal activity of Beauveria bassiana (Bb) and investigated the underlying synergistic mechanisms. Our results found that among 6 potential synergists, polyethylene glycol 400 (PEG) and trehalose significantly improved Bb's lethality against Hyphantria cunea larvae, with PEG demonstrating the most pronounced effect. PEG treatment markedly increased Bb spore adhesion and germination rates, while spore hydrophobicity and growth rates remained unaffected. Moreover, PEG-treated spores exhibited higher thermal tolerance compared to untreated ones. In the Bb + PEG treatment group, the hemocyte count, encapsulation and melanization activities, and the expression of related regulatory genes were significantly lower than those in the Bb treatment group. Additionally, pathogen recognition, signal transduction, and humoral immunity effector genes expression were markedly suppressed in the Bb + PEG group. A significant reduction in the content of total amino acids, free fatty acids, glucose, and trehalose, alongside decreased expression of key regulatory genes in the tricarboxylic acid cycle and glycolysis pathways, was observed in the Bb + PEG treatment group. Furthermore, PEG enhanced Bb-induced apoptosis in H. cunea larvae, as evidenced by the upregulation of apoptosis-related genes. Notably, PEG alone did not significantly impact the innate immunity, energy metabolism, or apoptosis in H. cunea larvae. Overall, PEG exhibits considerable potential in amplifying Bb's insecticidal activity by directly optimizing spore performance and indirectly modulating the larvae's innate immunity, energy metabolism, and apoptosis.

Effectiveness of Mechanical Bowel Preparation before Robot-Assisted Laparoscopic Gynecologic Surgery: A Randomized, Single-Blind, Controlled Trial

Objective: The objective of this randomized controlled trial was to compare the effect of bowel preparation using only oral polyethylene glycol electrolyte (PEG) solution versus oral PEG solution combined with mechanical sodium phosphate (NaP) enema on the surgical field visualization in patients undergoing robot-assisted laparoscopic gynecologic procedures. Methods: Participants were randomized to either a single oral PEG solution or an oral PEG solution combined by mechanical NaP enema. The intraoperative visualization of the surgical field, the ease of manipulation of the bowels, and overall difficulty level of the surgery were evaluated by the surgeon using a self-administered questionnaire. After the surgery, the patients completed a survey assessing postoperative gastrointestinal discomfort. Results: A total of 114 women were enrolled and randomized to oral PEG solution-only group (n = 48), and oral PEG plus mechanical NaP enema group (n = 66). Forty-two women in oral PEG-only group and 59 oral PEG plus NaP enema group completed the study. There was no difference in intraoperative visualization or overall difficulty of the operation between the two groups, and bowel manipulation was easier in the oral PEG-only group. Also, there was no difference in operating time between the groups. The patients’ level of gastrointestinal discomfort after the surgery was not significantly different between the two groups. Conclusion: Routine use of mechanical NaP enema before robot-assisted laparoscopic gynecologic surgery is not recommended, because it has no additional benefit regarding intraoperative visualization or the surgical level of difficulty over oral bowel preparation methods.

PEG 300 Promotes Mesodermal Differentiation in iPSC-Derived Embryoid Body Formation In Vitro.

Embryoid bodies (EB) are sensitive to changes in the culture conditions. Recent studies show that the addition of PEG 300 to culture medium affects cell growth and differentiation; however, its effect on the embryoid body is unclear. This study aims to understand the role of PEG 300 in the process of EB formation and germ layer differentiation. EBs formed more efficiently and differentiated toward the mesoderm when cultured in a medium supplemented with appropriate concentrations of PEG 300. The expression of T/Bry, a marker of mesodermal differentiation, increases in EBs in the PEG group, and the expression of TUBB3 generally decreases, showing a quantitative relationship with PEG. Furthermore, further differentiation of PEG-pretreated EB into vascular smooth muscle cells (VSMCs) by directional induction shows that PEG 300-pretreated induced VSMCs have higher expression of phenotypic markers and greater secretory and contractile functions. This study highlights the role of PEG 300 in the culture medium during EB differentiation, which can significantly enhance mesodermal gene expression and the efficiency of subsequent differentiation into smooth muscle cells and other target cells.

Pilot scale fabrication of low fouling seawater desalination thin film composite reverse osmosis membrane

We report the pilot scale fabrication of thin film composite seawater reverse osmosis membrane (TFC-SW-RO) with low fouling propensity and improved permeate flux. In situ incorporation of poly(ethylene glycol) (PEG) into the polyamide (PA) network simultaneously improves the permeate flux (effect of hydrophilic channels) and antifouling property of the membrane. The PEG chains exhibit good stability during desalination of SW (NaCl = 33,000 mg L−1, applied pressure = 55.2 bar). The mechanism of PEG stabilization into the PA layer has been elucidated on the basis of hydrogen bond formation between ether linkage of PEG and carboxylic acid group of the PA network as well as steric hindrance posed by the network. The TFC-SW-RO membrane (no PEG) in several 100 m2 batches show pure water permeance of 1.4 L m−2 h−1 bar−1 and 98.5–98.8 % NaCl rejection during SW desalination. On the other hand, TFC-SW-RO-PEG shows pure water permeance of 2.2 L m−2 h−1 bar−1 with marginal drop in NaCl rejection (98.4–98.6 %). The TFC-SW-RO-PEG membrane exhibits improved antifouling (flux recovery ratio = 87 %) property during desalination of SW as compared to that of the pristine membrane (flux recovery ratio = 67 %). This work provides an important strategy for the fabrication of SW TFC RO membrane with improved performance.

A novel PEGylated form of granulocyte colony-stimulating factor, mecapegfilgrastim, for peripheral blood stem cell mobilization in patients with hematologic malignancies.

The Pegylated recombinant human granulocyte colony stimulating factor (PEG-rhG-CSF) has longer half-life and is given once only, which is more comfortable for patients. We aimed to evaluate the efficacy of mecapegfilgrastim for hematopoietic stem cell (HSC) mobilization in patients with hematologic malignancies and to explore the potential factors related to HSC mobilization. A retrospective analysis was performed on patients who underwent HSC mobilization in the hematology department of Mianyang Central Hospital from April 2016 to November 2022. The number of CD34 + cells collected was compared between the patients receiving mecapegfilgrastim (PEG group) and those receiving recombinant human granulocyte colony-stimulating factor (rhG-CSF group), and the possible factors for mobilization failure were analyzed. The success rates of collecting CD34 + cells in the PEG group and rhG-CSF group were 80.6% and 67.7%, respectively (χ = 1.444, P = 0.229). The median CD34 + cell counts were 3.62 × 10^6/kg and 2.92 × 10^6/kg (P = 0.178), respectively. After combination with plerixafor for mobilization, the median number of CD34 + cells collected in the PEG group and rhG-CSF group were 3.64 × 10^6/kg and 3.92 × 10^6/kg, respectively, with no significant difference (P = 0.754). There was no significant difference in hematopoietic cell recovery or infection between the groups (P > 0.05). Multivariate analysis showed that more than 5 cycles of chemotherapy (OR = 15.897, 95% CI: 1.766-143.127, P = 0.014), a precollection WBC count < 32 × 10^9/L (OR = 14.441, 95% CI: 2.180-95.657, P = 0.006) and a precollection to premobilization lymphocyte ratio < 1.7 (OR = 11.388, 95% CI: 2.129-60.915, P = 0.004) were independent risk factors for HSC mobilization failure. The HSC mobilization efficacy of mecapegfilgrastim in patients with hematologic malignancies was comparable to that of rhG-CSF, and combination with plerixafor for mobilization was feasible and effective. Patients with more than 5 cycles of chemotherapy before HSC mobilization, a precollection WBC count lower than 32 × 10^9/L, and a precollection lymphocyte count less than 1.7 times the premobilization lymphocyte count have a high probability of HSC mobilization failure.

BIO9: The Addition of High Molecular Weight Linear Polymers Improves Microvascular Perfusion in an Animal Model of Veno-arterial Extracorporeal Circulation.

High molecular weight linear polymers have been used in turbulent flow applications such as crude oil transfer to reduce drag. These polymers have branched into bioengineering applications to improve pressure changes within the macrocirculation and improve RBC distribution within the microcirculation. The current study aims to determine whether the addition of these polymers to priming fluids used for veno-arterial extracorporeal circulation (VA-ECC) procedures improve microvascular flow and tissue oxygenation. To assess the microcirculation, male Golden Syrian hamsters were instrumented with a dorsal skinfold window chamber, and an exteriorized carotid artery catheter was implanted for arterial blood and blood pressure access. After baseline (BL) measurements were taken, the hamster underwent surgery under isoflurane to insert a drainage catheter into the jugular vein. A heparin bolus (0.05 IU/g) was then provided, and the animal was connected to the VA-ECC circuit. The circuit, consisting of a peristaltic pump and bubble trap, was primed with lactated ringers (LR, control), LR with 5 ppm of 500 kDa polyethylene glycol (PEG500k) or LR with 5 ppm of 3500kDa polyethylene glycol (PEG3500k). Blood flow was ramped up over 15 minutes, maintained at 15% of the animal’s cardiac output for 60 minutes, then ramped down over 15 minutes. The animal was then surgically closed and placed on a heating pad and allowed at least 30 minutes to wake up from the anesthetic plane before taking measurements at 1, 2, and 24 hours after VA-ECC. Capillary perfusion (Figure 1) within the skinfold preparation showed a significant decrease immediately post-ECC for all three groups. However, the PEG3500k group consistently showed significant increase in functional capillary density (FCD) as compared to both other groups after ECC. 24 hrs after ECC, FCD was recovered close to BL levels for both PEG groups, while the LR control did not. Arteriole and venule velocity (Figure 2) was significantly elevated at both 1 and 2 hrs post-ECC for the PEG3500k group when compared to the other two groups. Arteriole flow for the PEG3500k was significantly improved over the LR control at 24 hrs post-ECC, and was significantly higher than BL levels. Hemoglobin saturation within arterioles and venules (Figure 3) revealed that PEG3500k had higher venule saturation at 1 and 2 hrs post-ECC compared to both other groups. The results indicate that the use of PEG3500k improved microvascular perfusion acutely post-ECC, and continued to up to 24 hrs afterwards. The most important changes were in arteriole perfusion and FCD, since that directly impacts oxygen delivery and metabolic washout respectively. Ultimately, this aids in maintaining organ function and preventing the development of ischemic injury and inflammatory cascades. Future studies could optimize the molecular weight, concentration, and type of polymer, along with testing in a clinical ECC circuit to determine hemodynamic changes.Figure 1. Functional capillary density (FCD), normalized to baseline (BL, represented by the dotted line). † P < 0.05 as compared to BL, within each group. * P < 0.05; ** P < 0.01; *** P < 0.001 between groups, at each timepoint.Figure 2. Perfusion within the microcirculation. From top to bottom: diameter, velocity, blood flow. Arterioles are on the left, while venules are on the right. Note that all values were normalized to baseline (BL, represented by the dashed line) and that blood flow was calculated from the diameter and velocity measurements of each vessel. Bar plots represent mean and standard deviation. † P < 0.05 as compared to BL, within each group. * P < 0.05; ** P < 0.01; *** P < 0.001; **** P < 0.0001 between groups, at each timepoint.Figure 3. Hemoglobin oxygen saturation within the microcirculation. Top = arterioles, bottom = venules. Bar plots show mean and standard deviation. † P < 0.05 as compared to BL, within each group. * P < 0.05; ** P < 0.01; *** P < 0.001; **** P < 0.0001 between groups, at each timepoint.

Effect of sainfoin proanthocyanidins on milk fatty acids from ewes rearing suckling lambs

Proanthocyanidins (PAC) can modulate the fatty acid (FA) profile of animal products and make them healthier for human consumption, but their effects are highly variable depending on several factors such as PAC chemical structure or dose. The present experiment aimed to evaluate the effect of PAC on the milk FA profile of Rasa Aragonesa ewes fed fresh sainfoin (PAC-containing forage legume) during the rearing period of suckling lambs (4 weeks postlambing). Twenty lactating ewes rearing a single male lamb were fed fresh sainfoin ad libitum plus 200 g/d of barley. Half the ewes were orally dosed with 100 mL of water (Sainfoin Group; n = 10) and the other half with polyethylene glycol (50 g PEG4000/100 mL water, Sainfoin + PEG Group; n = 10) to block PAC effects. Sainfoin and milk samples were collected weekly to determine their FA profile by gas chromatography. Fresh sainfoin contents of C18:3n-3 decreased from week 1 to week 2, C16:0 and C18:0 increased from week 1 to week 3, and C18:2n-6 did not change. Regarding milk FA, there were minor effects of PAC on milk-saturated FA. During the whole study, the presence of PAC increased C18:0, C18:2n-6, C18:3n-3 and total polyunsaturated FA (PUFA) n-6 and n-3, and decreased C18:1 t11, branched- and odd-chain FA. However, the decrease of milk concentrations of trans-monounsaturated FA, C18:1 t10, and total conjugated linoleic acid (CLA) and the increase of total PUFA due to the presence of PAC occurred only in week 1, while CLA c9,t11 was lower during weeks 1 and 2. The canonical analyses confirmed the differences between treatments in the FA profile of milk. Overall, the use of fresh sainfoin in the diet of lactating ewes resulted in a beneficial modification of the concentration of several milk FAs, suggesting some changes in ruminal biohydrogenation.

Effects of PEG in patients with esophageal squamous cell carcinoma during concurrent chemoradiotherapy: a prospective study

This prospective study aimed to compare the changes in nutritional status and adverse events among patients with esophageal squamous cell carcinoma who received enteral nutrition through oral intake, PEG, and an enteral nasogastric tube (NGT) during concurrent chemoradiotherapy (CCRT). Of 141 included patients, 38, 74, and 29 patients were fed through oral intake, PEG, and NGTs, respectively. The clinical characteristics and baseline nutritional status of the 3 groups were recorded and analyzed. The Patient-Generated Subjective Global Assessment score, skeletal muscle index, and quality of life were evaluated before and after CCRT; the incidence of adverse events during feeding using PEG and NGTs was also recorded. The correlations among the different nutritional pathways and the CCRT-related adverse events (eg, radiation esophagitis and myelosuppression) were assessed. At baseline, the oral intake group had a significantly better nutritional status and lower disease stage than those in the PEG and NGT groups. However, during CCRT, the oral intake group exhibited the most significant decreases in weight and skeletal muscle index. The synchronous chemotherapy completion rate was the highest in the PEG group. Multivariate analysis showed that the planning tumor volume and oral intake and NGT feeding pathways were associated with radiation esophagitis of at least grade2. We found that PEG effectively maintained the body weight and skeletal muscle index of patients with esophageal cancer during CCRT. PEG also improved the synchronous chemotherapy completion rate and reduced the occurrence of at least grade 2 radiation esophagitis. (Clinical trial registration number: NCT04199832.).

Preoperative Elective Bowel Preparation In Children With Polyethylene Glycol Versus Polyethylene Glycol and Mannitol - A Comparative Study

Background: Oral mechanical bowel preparation is a routine practice prior to colorectal surgery in many centers. Virtually all colorectal surgeons consider a mechanically cleansed and empty bowel as one of the prerequisites for a safe colonic resection and anastomosis. Various agents had been used in different centers in mechanical bowel preparation. Methods: A comparative prospective interventional analysis of preoperative elective bowel preparation in children with polyethylene glycol versus polyethylene glycol and mannitol was conducted on 60 children underwent elective GIT surgery between July 2014 and June 2016. The patients were allocated into 2 groups by simple random sampling, 30 in each group. Children of 6 months to 14 years were selected as study population. In group I, PEG was given per orally or through nasogastric tube at the rate of 1.5 gm powder/kg/dose, in group II, PEG &amp; Mannitol were given orally or via nasogastric tube. PEG was administered as same dose of group I and mannitol 20% at a dose of 10 ml/kg/dose. All patients received prophylactic intravenous antibiotics (ceftriaxone + metronidazole) preoperatively as well as in postoperative period. All children were investigated preoperatively and post operative follow up was recorded. Structured questionnaire was used to collect information regarding preoperative status and post operative follow up. Statistical assessments were done by SPSS version 21. An Ethical clearance had been sought. Results: Sixty children underwent mechanical bowel preparation prior to GIT surgery. 30 with PEG (group I) and 30 with PEG and Mannitol (group II). Our outcome variables were wound infection, anastomotic leakage, and Electrolyte balance. Demographic pattern also evaluated. The age range of both groups was 6-68 months, p value 0.987. In both group male and female were same in number, 16 male and 14 female each in both groups. Wound infection occurred 3 cases (10%) in PEG group and 2 cases in PEG and Mannitol group, p value 0.64. No anastomotic leakage in PEG and Mannitol group and only 1 leakage in PEG group. No Electrolyte imbalance was found in both groups. No mortality was recorded in this study. Conclusions: No significant difference was found between the two study groups in respect of wound infection, anastomotic leakage and electrolyte balance. Ingestion of two drugs did not have any better outcome. So, mannitol can be omitted in MBP in children. J Dhaka Med Coll. 2022; 31(1) : 29-36

Application of Mecapegfilgrastim for Peripheral Blood Hematopoietic Stem Cell Mobilization in Patients With Hematologic Neoplasms and Analysis of Predictors for Poor Mobilization

To evaluate the efficacy of applying mecapegfilgrastim for peripheral blood hematopoietic stem cell (PBSC) mobilization in patients with hematologic neoplasms, and to investigate the influencing factors of PBSC collection. Patients who underwent PBSC mobilization in the Department of Hematology, Mianyang Central Hospital between April 2016 and May 2022 were retrospectively analyzed. The CD34 + cell collection results of two groups, the mecapegfilgrastim group ( n=28), or the PEG group, and the recombinant human granulocyte colony-stimulating factor (rhG-CSF) group ( n=30), were compared, and the influencing factors of collection failure were analyzed. The success rates of CD34 + cells collection in the PEG group and the rhG-CSF group were 75.0% and 63.3%, respectively ( P>0.05). The median CD34 + cell counts were 3.37×10 6/kg and 2.68×10 6/kg, respectively, showing no significant difference. After combined mobilization with plerixafor, the median counts of CD34 + cells collected in the PEG group and rhG-CSF group were 4.23×10 6/kg and 3.26×10 6/kg, respectively, showing no significant difference ( P>0.05). There was no significant difference in hematopoietic system reconstruction and infections between the two groups ( P>0.05). Multivariate analysis found non-plasma cell disease (odds ratio [ OR]=19.697, 95% confidence interval [ CI] : 1.501-258.537, P=0.023), anemia before collection ( OR=18.571, 95% CI: 1.354-254.775, P=0.029) and white blood cell count before collection under 32×10 9 L -1 ( OR=85.903, 95% CI: 4.947-1491.807, P=0.002) to be independent risk factors for PBSC collection failure. The effect of PBSC mobilization with mecapegfilgrastim was comparable to that of rhG-CSF in patients with hematologic neoplasms. Furthermore, combined mobilization with plerixafor was feasible and effective. Patients with leukemia or lymphoma, anemia, and WBC<32×10 9 L -1 before stem cell collection have a high probability of PBSC collection failure.

Development of PEGylated Cu nanoclusters: A nontoxic, multifunctional colloidal system for bioimaging and peroxide sensing

This study introduces the development of blue-emitting colloidal Cu NCs through a novel and easy PEGylation method using different functional groups, including -SH and -COOH. The surface functionalization controls the size, cellular toxicity, and emission properties of Cu NCs. The combination of PEG, thiol, and carboxylic groups protects the particle surface from aggregation and oxidation. Among the samples, CAGP (Surface modified Cu NCs with -SH-COOH-PEG combination) emerges as an amazing candidate with the lowest toxicity and enhanced blue emission properties. The bright blue fluorescence emission from Hela cells after treatment with CAGP demonstrated this property. It also has excellent peroxide sensing potential, with a detection limit of 1.4 μM. Because of their excellent bioimaging and peroxide sensing properties, these Cu NCs could be a promising candidate for cellular oxidative stress sensing applications with high clinical relevance.

A novel tetra-PEG based hydrogel for prevention of esophageal stricture after ESD in a porcine model

Endoscopic submucosal dissection (ESD) is an accepted treatment for early esophageal cancer and precancerous lesions, but resection of a large mucosal area often leads to postoperative esophageal stricture. Biomaterials provide a new option for the treatment of post-ESD ulcers. In this study, we developed a well-defined ammonolysis-based tetra-armed poly (ethylene glycol) (Tetra-PEG) hydrogel and investigated its efficacy and related mechanisms for preventing esophageal ESD-induced stricture in a porcine model. In terms of material properties, Tetra-PEG hydrogel present great biocompatibility，great capability to retain moisture, strong tissue adhesion and high mechanical strength. Then, six domestic female pigs were randomly divided into PEG (n = 3) and control groups (n = 3). A 3/4 of the esophageal circumference ESD was performed in all pigs. In PEG group, Tetra-PEG hydrogel was easily delivered via endoscopy and adhered to the ulcer bed tightly. Compared to control group, Tetra-PEG hydrogel accelerated esophageal ulcer healing at an early stage with enhanced epithelium regeneration, milder inflammation and lesser fibrosis by regulating TGF-β/Smad2 signaling. Taken together, our findings reveal Tetra-PEG hydrogel is a promising and attractive candidate for preventing the formation of fibrotic stricture in the process of esophageal ESD-induced ulcer repair.

Effectiveness of biosimilar pegfilgrastim in patients with multiple myeloma after high-dose melphalan and autologous stem cell transplantation

Multiple myeloma (MM) is the main indication for autologous stem cell transplantation (ASCT). Novel supportive therapies (e.g., granulocyte colony-stimulating factor) have significantly improved post-ASCT-related mortality; however, data on biosimilar pegfilgrastim-bmez (BIO/PEG) in this setting is lacking. This prospective cohort study compared Italian patients with MM who received BIO/PEG post-ASCT with data collected retrospectively from historical control groups from the same center who received either filgrastim-sndz (BIO/G-CSF) or pegfilgrastim (PEG; originator). The primary endpoint was time to neutrophil engraftment (three consecutive days with an absolute neutrophil count ≥ 0.5 × 109/L). Secondary endpoints included incidence and duration of febrile neutropenia (FN). Of the 231 patients included, 73 were treated with PEG, 102 with BIO/G-CSF, and 56 with BIO/PEG. Median age was 60 years and 57.1% were male. Neutrophil engraftment was reached after a median of 10 days in the BIO/PEG and PEG groups and 11 days in the BIO/G-CSF group. Among patients who achieved neutrophil engraftment earlier than this (i.e., day 9), 58% (29/50) were on PEG; of those who achieved it later (i.e., day 11), 80.8% (59/73) were on BIO/G-CSF. FN incidence was higher with BIO/G-CSF (61.4%) versus PEG (52.1%) or BIO/PEG (37.5%) (p = 0.02 among groups). Patients on BIO/PEG had less frequent grade 2–3 diarrhea (5.5%) compared with BIO/G-CSF (22.5%) or PEG (21.9%); grade 2–3 mucositis was most frequent in the BIO/G-CSF group. In conclusion, pegfilgrastim and its biosimilar displayed an advantageous efficacy and safety profile compared with biosimilar filgrastim in patients with MM post-ASCT.

Designing Viscoelastic Gelatin-PEG Macroporous Hybrid Hydrogel with Anisotropic Morphology and Mechanical Properties for Tissue Engineering Application

The mechanical properties of scaffolds play a vital role in regulating key cellular processes in tissue development and regeneration in the field of tissue engineering. Recently, scaffolding material design strategies leverage viscoelasticity to guide stem cells toward specific tissue regeneration. Herein, we designed and developed a viscoelastic Gel-PEG hybrid hydrogel with anisotropic morphology and mechanical properties using a gelatin and functionalized PEG (as a crosslinker) under a benign condition for tissue engineering application. The chemical crosslinking/grafting reaction was mainly involved between epoxide groups of PEG and available functional groups of gelatin. FTIR spectra revealed the hybrid nature of Gel-PEG hydrogel. The hybrid hydrogel showed good swelling behavior (water content &gt; 600%), high porosity and pore interconnectivity suitable for tissue engineering application. Simple unidirectional freezing followed by a freeze-drying technique allowed the creation of structurally stable 3D anisotropic macroporous architecture that showed tissue-like elasticity and was capable of withstanding high deformation (50% strain) without being damaged. The tensile and compressive modulus of Gel-PEG hybrid hydrogel were found to be 0.863 MPa and 0.330 MPa, respectively, which are within the range of normal human articular cartilage. In-depth mechanical characterizations showed that the Gel-PEG hybrid hydrogel possessed natural-tissue-like mechanics such as non-linear and J-shaped stress-strain curves, stress softening effect, high fatigue resistance and stress relaxation response. A month-long hydrolytic degradation test revealed that the hydrogel gradually degraded in a homogeneous manner over time but maintained its structural stability and anisotropic mechanics. Overall, all these interesting features provide a potential opportunity for Gel-PEG hybrid hydrogel as a scaffold in a wide range of tissue engineering applications.

Maternal treatment with pegbovigrastim influences growth performance and immune-metabolic status of calves during the pre-weaning period

This study aimed to investigate the immune-metabolic status and growth performance of Simmental calves born from cows subjected to pegbovigrastim administration 7 days before calving. Eight calves born from cows subjected to pegbovigrastim administration (PEG group) and 9 calves born from untreated cows (CTR group) were used. Growth measurements and blood samples were collected from birth to 60 d of age. The PEG group had lower body weight from 28 up to 60 d of age (P < 0.01), lower heart girth (P < 0.05), lower weekly and total average daily gain values (P < 0.05) than the CTR group throughout the monitoring period. A decrease in milk replacer (MR) intake was observed in the PEG group compared with the CTR group around 20–28 d of age (P < 0.01). The PEG group had lower values of γ-glutamyl transferase (GGT) at d 1 of age (P < 0.05), Zn at 21 and 28 d of age (P < 0.05), hemoglobin, MCH and MCHC at 54 and 60 d of age (P < 0.01), and higher urea concentration at 21 and 28 d of age (P < 0.05) compared with the CTR group. Lower values of retinol (P < 0.05), tocopherol (P < 0.01), mean myeloperoxidase index (P < 0.05) and higher total reactive oxygen metabolites (P < 0.05) and myeloperoxidase (P < 0.05) were also detected in the PEG group. In light of the results gathered in the current study, it can be speculated that activation of the cow's immune system by pegbovigrastim could have influenced the immune competence, growth performance as well as the balance between oxidant and antioxidant indices of the newborn calf.

Crosslinking two-dimensional metalloporphyrin (Me-TCPP) nanosheet with poly(ethylene) glycol semi-interpenetrating polymer network for ultrahigh CO2/N2 separation selectivity via “rubber-band” straightening effect

To efficient separate carbon dioxide from power plant flue gas, three two-dimensional (2D) metalloporphyrin (Me-TCPP) nanosheets, Zn-TCPP, Cu-TCPP, and Ni-TCPP are crosslinked with poly(ethylene) glycol (PEO) semi-interpenetrating polymer via “rubber-band” straightening effect. Dispersion-corrected periodic density functional (DFT-D2) calculation reveals that the lowest N4-Metalδ+···Oδ− distance (2.81 Å) and the highest binding energy (19.9 kJ mol−1) are obtained between CO2 molecule and metalloporphyrin center (Zn–N4), as well as the lowest O4-Metalδ+···Oδ− distance (4.68 Å) and the highest binding energy (18.8 kJ mol−1) on metal cluster (Zn–O4). The 2D Zn-TCPP nanosheet with the strongest affinity toward CO2 molecule generates Zn2+-CO2 complex to remarkably boost CO2 solubility in mixed matrix membrane (MMMs). Thus, 2.5 wt% Zn-TCPP nanosheet incorporated PEO-based MMMs dramatically promotes CO2 permeability to 198 Barrers and ultrahigh CO2/N2 selectivity to 81. A novel “rubber-band” straightening effect is found and verified, which is induced by abundant interfacial coordination bonds between metal ions in nanosheets and ester groups (O–CO) in PEO polymer chains, the strong Me–O–CO interaction sites hold polymer chains and lead to their regular rearrangement. Owing to the abundant PEG groups in PEGMEA macromolecule chains, incorporating 1 wt% Zn-TCPP nanosheet into crosslinked XLPEGDAcoPEGMEA polymer achieves the highest CO2 permeability of 398 Barrers.

The preservation of sarin and O,O'-diisopropyl fluorophosphate inside coordination cage hosts.

The host-guest chemistry of O,O'-diisopropyl fluorophosphate (DFP), a phosphonofluoridate G-series chemical warfare agent simulant, was investigated in the presence of a number of octanuclear cubic coordination cage hosts. The aim was to demonstrate cage-catalysed hydrolysis of DFP at near neutral pH: however, two octanuclear coordination cages, HPEG (containing water-solubilising PEG groups) and HW (containing water-solubilising hydroxymethyl groups), were actually found to increase the lifetime of DFP in aqueous buffer solution (pH 8.7). Crystallographic analysis of DFP with a structurally related host cage revealed that DFP binds to windows in the cage surface, not in the internal cavity. The phosphorus-fluorine bond is directed into the cavity rather than towards the external environment, with the cage/DFP association protecting DFP from hydrolysis. Initial studies with the chemical warfare agent (CWA) sarin (GB) with HPEG cage in a buffered solution also showed a drastically reduced rate of hydrolysis for sarin when bound in the host cage. The ability of these cages to inhibit hydrolysis of these P-F bond containing organophosphorus guests, by encapsulation, may have applications in forensic sample preservation and analysis.

Preclinical PET and MR Evaluation of 89Zr- and 68Ga-Labeled Nanodiamonds in Mice over Different Time Scales.

Nanodiamonds (NDs) have high potential as a drug carrier and in combination with nitrogen vacancies (NV centers) for highly sensitive MR-imaging after hyperpolarization. However, little remains known about their physiological properties in vivo. PET imaging allows further evaluation due to its quantitative properties and high sensitivity. Thus, we aimed to create a preclinical platform for PET and MR evaluation of surface-modified NDs by radiolabeling with both short- and long-lived radiotracers. Serum albumin coated NDs, functionalized with PEG groups and the chelator deferoxamine, were labeled either with zirconium-89 or gallium-68. Their biodistribution was assessed in two different mouse strains. PET scans were performed at various time points up to 7 d after i.v. injection. Anatomical correlation was provided by additional MRI in a subset of animals. PET results were validated by ex vivo quantification of the excised organs using a gamma counter. Radiolabeled NDs accumulated rapidly in the liver and spleen with a slight increase over time, while rapid washout from the blood pool was observed. Significant differences between the investigated radionuclides were only observed for the spleen (1 h). In summary, we successfully created a preclinical PET and MR imaging platform for the evaluation of the biodistribution of NDs over different time scales.

PEG-functionalized carbazole-based polymers for UV-protected hydrophilic glass coatings

The UV-absorbing and non-fogging glass coatings containing carbazole-based conjugated backbone with different lengths of hydrophilic PEG subunit (KP-PEG) were produced. The characterizations of the polymers were carried out by using different techniques such as FT-IR, 1H NMR, GPC, TGA and DSC. Transmittance and thin-film morphology analyses, which are essential for UV protection and wettability, were investigated by UV–Vis absorption, AFM and TEM techniques, respectively. Transparent thin films prepared by the polymer solutions in chloroform were obtained by spin coating method at a scan rate of 2000 rpm. The wettability performance and antifogging properties of these surfaces were investigated depending on the PEG length in the polymer subunit. The water contact angle of the surfaces was improved to the range between 60° and 29° depending on the amount of PEG group. KP-PEG750 is the best polymer thin film in terms of having the highest roughness, optimum UV absorption and the low contact angle value.