Traditional PEG Research Articles

Metal-organic frameworks and polymer nanoplatform: Biocompatible and photothermal responsive tribromoethanol anesthetic for mice

Effective anesthesia is crucial for ensuring the validity and reliability of animal experiments. In recent years, tribromoethanol has been widely used for small animal anesthesia. However, direct injection poses risks of overdose, anesthesia instability, and organ damage, affecting experimental reliability and animal welfare. Therefore, developing a safer and more stable delivery system for tribromoethanol is essential. In this study, we first synthesized two complexes using a solvothermal method. Then, we modified the traditional biopolymer PEG to synthesize an amphiphilic block copolymer, Cyanine 7-PEG-DDAT, which was used to coat CP1 and load tribromoethanol (TBE) for structural characterization. We then conducted biological tests on Cyanine 7-PEG-DDAT-CP1@TBE and compared its anesthetic effects in C57BL/6 mice with those of direct tribromoethanol injection. The results provide a reference for the application of tribromoethanol in mouse models and surgeries.

The Development of Traditional Games Patok Lele towards Sport Science, Health and Education Learning at SDN 15 Sitiung Dharmasraya

Study background back by lack of interest student in play game traditional So needed game game traditional in PJOK learning for increase interest students Based on problem the so researcher develop game traditional peg catfish.Development using the research and development (R&D) Borg & gall model, model development borg & Gall has ten step. On step. On step study this is shared Becomes two stages, that is Step preliminary and Step development. Two stages that explained as following: 1) Potential and problem; 2) Data Collection; 3) Design product; 4) Validation product; 5) Revision usage; 6) Test try early; 7) Revision product. Whereas stage 8) Test try usage; 9 ) Revision product; 10) Production bulk no conducted in study because concerned with financing publishing products in the field mass.Results evaluation sheet validation game traditionally done by four validators generate the average value of 77% is categorized very valid. Test practicality by PJOK teacher with 100% percentage is categorized very practical and student with percentage 90% categorized very practical, while test 76% effectiveness categorized effective, based on results obtained so game traditional peg catfish in PJOK learning is categorized as valid, practical, and effective

Development of Nanosilicate-Hydrogel Composites for Sustained Delivery of Charged Biopharmaceutics.

Nanocomposite hydrogels containing two-dimensional nanosilicates (NS) have emerged as a new technology for the prolonged delivery of biopharmaceuticals. However, little is known about the physical-chemical properties governing the interaction between NS and proteins and the release profiles of NS-protein complexes in comparison to traditional poly(ethylene glycol) (PEG) hydrogel technologies. To fill this gap in knowledge, we fabricated a nanocomposite hydrogel composed of PEG and laponite and identified simple but effective experimental conditions to obtain sustained protein release, up to 23 times slower as compared to traditional PEG hydrogels, as determined by bulk release experiments and fluorescence correlation spectroscopy. Slowed protein release was attributed to the formation of NS-protein complexes, as NS-protein complex size was inversely correlated with protein diffusivity and release rates. While protein electrostatics, protein concentration, and incubation time were important variables to control protein-NS complex formation, we found that one of the most significant and less appreciated variable to obtain a sustained release of bioactive proteins was the buffer chosen for preparing the initial suspension of NS particles. The buffer was found to control the size of nanoparticles, the absorption potential, morphology, and stiffness of hydrogels. From these studies, we conclude that the PEG-laponite composite fabricated is a promising new platform for sustained delivery of positively charged protein therapeutics.

Peg solitaire in three colors on graphs

Peg solitaire is a classical one-person game that has been played in various countries on different types of boards. Numerous studies have focused on the solvability of the games on these traditional boards and more recently on mathematical graphs. In this paper, we go beyond traditional peg solitaire and explore the solvability on graphs with pegs of more than one color and arrive at results that differ from previous works on the subject. This paper focuses on classifying the solvability of peg solitaire in three colors on several different types of common mathematical graphs, including the path, complete bipartite, and star. We also consider the solvability of peg solitaire on the Cartesian products of graphs.

Clinical Features and Advantages of a Novel Percutaneous Endoscopic Gastrostomy Method.

BackgroundTo study the clinical characteristics of novel percutaneous endoscopic gastrostomy.Material/MethodsWe retrospectively analyzed the hospital records of 173 patients undergoing various methods of gastrostomy (a novel PEG, traditional PEG, and surgical gastrostomy). Clinical characteristics were analyzed. For the novel PEG, the operation was as same as the traditional method for initial steps until the annular guide wire was inserted. The following steps were different: water was injected through an injection port to expand the capsule, then the water sac was confirmed to be close to the gastric wall under endoscope, and, finally, the incision was sutured and covered.ResultsPatient ages ranged from 42 to 93 years (60.8±9.2 years, 91 males and 82 females). Among all patients, there were 27 cases of brain trauma, 42 cases of cerebral infarction, 74 cases of esophageal or cardiac carcinoma, 21 cases of laryngocarcinoma, and 9 cases of Alzheimer disease. Clinical features were significantly better for novel PEG compared to traditional PEG: duration of operation (19.75±3.14 min vs. 37.86±5.33 min and 54.12±9.48 min, P<0.001), intraoperative blood loss (27.14±3.63 ml vs. 43.53±6.24 ml and 75.78±12.41 ml, P<0.001), postoperative pain score (1.12±0.19 pts vs. 3.85±0.44 pts and 6.22±1.06 pts; P<0.001), infection rate (1.35% vs. 3.77% and 2.17%, P<0.001), length of hospital stay (3.16±0.42 d vs. 5.68±0.78 d and 8.29±1.31 d, P<0.001), and time to free activity (2.24±0.26h vs. 3.74±0.48 h and 14.85±2.38 d, P<0.001). The incidence of complications such as wound infection (1.35% vs. 3.77% and 4.76%), vomiting (1.35% vs. 5.66% and 6.52%), and nausea (2.70% vs. 1.88% and 6.52%) in the novel PEG group was lower than in the other groups (P<0.0001). Improved outcomes were obtained without increased medical costs in the novel PEG group.ConclusionsFor patients with difficult postoperative oral nutrition, the novel PEG treatment resulted in overall better clinical outcomes than traditional PEG.

Load-Carrying Capacity and Stiffness of Softwood Wooden Dowel Connections

ABSTRACT Historically, wooden peg connections have been widely used in timber joints, particularly during the Middle Ages, and the use of these wooden connections is becoming popular again. In this article, an experimental investigation of seven different combinations of pegged connection parameters is presented. Embedment, single-shear, and double-shear tests of pine peg connections were loaded parallel and perpendicular to the grain under monotonic static compressive loads. Pegs of 10, 15, and 20 mm diameters were tested in three different shapes: straight cylindrical, straight traditional, and conical traditional. All peg shapes exhibited similar maximum loads, but straight traditional pegs exhibited greater stiffness than cylindrical pegs due to the tight fit of the peg. The ultimate load capacities of the straight traditional and cylindrical peg connections were then compared to a model based on Johansen’s theory of timber connections and were accurately predicted in both single and double shear.

Shell-Sheddable Poly(N-2-hydroxypropyl methacrylamide) Polymeric Micelles for Dual-Sensitive Release of Doxorubicin.

Poly(ethylene glycol) (PEG) shell-sheddable micelles are proved to be effective tools for rapid intracellular drug delivery. However, some adverse factors, such as the potential immunogenicity and the accelerated blood clearance, might be accompanied with the traditional PEG sheddable micelles. Here, a poly(N-2-hydroxypropyl methacrylamide) (PHPMA) sheddable block copolymer containing disulfide bonds on the main chain is prepared to form pH- and reduction-dual-responsive micelles. The most optimal synthetic route of the block copolymer is selected from three potential pathways. Doxorubicin is loaded via an acid-labile hydrazone bond to achieve high drug loading content and to prevent premature drug release. As expected, as-prepared shell-sheddable micelles exhibit faster intracellular drug release and more satisfactory in vitro anticancer efficacy than the nonsheddable counterpart did. This design provides a feasible guideline for the efficient synthesis of similar shell-sheddable micelles consisting of PHPMA coatings.

Exploring zwitterionic siRNA polyplex coronas as an alternative to traditional PEGylated architectures for improved intravenous pharmacokinetics

Event Abstract Back to Event Exploring zwitterionic siRNA polyplex coronas as an alternative to traditional PEGylated architectures for improved intravenous pharmacokinetics Meredith Jackson1, Thomas A. Werfel1, Zoe E. Johnson1, Todd D. Giorgio1 and Craig L. Duvall1 1 Vanderbilt University, Biomedical Engineering, United States Introduction: Despite the use of PEGylation to improve in vivo stability of traditional polymeric siRNA delivery vehicles, circulation half-lives remain short (~20 min) [1]. Serum opsonins and complement proteins adsorb onto these particles, decreasing stability and increasing recognition and uptake by the mononuclear phagocyte system (MPS)[2]-[4]. To improve intravenous polyplex delivery of RNAi therapeutics, it is imperative to design nanocarriers with improved resistance to the challenges of a complex protein environment. The current work compares zwitterionic corona chemistry to traditional linear and branched PEG-based architectures for predictors of best in vivo function. To our knowledge, this work describes and provides initial characterization of the first endosomolytic zwitterion-based polymeric siRNA delivery system. Materials and Methods: Poly[(ethylene glycol)-b-[(2-dimethylamino)ethyl methacrylate) (DMAEMA)-co-(butyl methacrylate) (BMA)] (PEG-DB), poly[(ethyl ether methacrylate) (POEGMA)-b-p(DMAEMA-co-BMA)] (POEGMA-DB), and poly(methacryloyloxyethylphosphorylcholine (PMPC)-b-p(DMAEMA-co-BMA)] (PMPC-DB), were RAFT polymerized with an optimized 50:50 ratio of DMAEMA and BMA[5]. Polymers were characterized with GPC and 1H-NMR. Polyplexes formulated from these polymers and siRNA were characterized with DLS and TEM. These polyplexes were assessed for uptake and in vitro knockdown of the model gene luciferase in breast cancer cells (MDA-MB-231), as well as for endosomal escape function and cytotoxicity. Finally, isothermal titration calorimetry was used to probe adsorption of bovine serum albumin. Results and Discussion: Overall, zwitterionic PMPC-DB notably outperformed PEG-DB and POEGMA-DB in terms of increased cell uptake (Fig 1C) and reduced protein adsorption (Fig 2). Each polymer formed siRNA polyplexes of similar size (~150 nm) and had neutral zeta potential with low polydispersities. All polyplexes exhibit similar knockdown of the model gene luciferase (Fig 1B) and equally low levels of toxicity. Based on isothermal titration calorimetry (Fig 2), zwitterionic PMPC-DB was least favorable to protein adsorption compared to PEG-DB, POEGMA-DB, and a control formulation with a purely cationic DMAEMA corona (D-DPB), as evidenced by its large change in Gibbs free energy (ΔG). However, PMPC-DB had the greatest increase in enthalpy, suggesting that more energy is required to displace the hydration shell of zwitterionic polyplex coatings than for traditional PEG coatings. While the displacement of cage-like hydration shells resulted in favorable entropy changes for PMPC-DB, this effect was outweighed by the enthalpy required to displace them, resulting in higher ΔG values. Conclusion: In conclusion, novel zwitterionic siRNA polyplex coronas show promise for improved in vivo pharmacokinetics relative to conventional PEG based on increased uptake and reduced adsorption of serum proteins. This is a significant finding as there is a known direct correlation between level of opsonization and rapidity of hepatic uptake of IV-injected nanocarriers [4]. In vivo pharmacokinetic effects of the PMPC corona will be compared to PEG in ongoing studies. This work was supported in part by National Science Foundation Graduate Research Fellowship Grant No. 1445197.; We would like to thank members of the Duvall and Giorgio labs for scientific discussions and support regarding this work.; We would like to thank Dr. Joel Tellinghuisen for his guidance regarding isothermal titration calorimetry methods.; This work was supported in part by the NIH through the grant 1R01EB019409.

Endothelial cell response to chemical, biological, and physical cues in bioactive hydrogels.

The highly tunable biological, chemical, and physical properties of bioactive hydrogels enable their use in an array of tissue engineering and drug delivery applications. Systematic modulation of these properties can be used to elucidate key cell-material interactions to improve therapeutic effects. For example, the rate and extent of endothelialization are critical to the long-term success of many blood-contacting devices. To this end, we have developed a bioactive hydrogel that could be used as coating on cardiovascular devices to enhance endothelial cell (EC) adhesion and migration. The current work investigates the relative impact of hydrogel variables on key endothelialization processes. The bioactive hydrogel is based on poly(ethylene glycol) (PEG) and a streptococcal collagen-like (Scl2-2) protein that has been modified with integrin α1β1 and α2β1 binding sites. The use of PEG hydrogels allows for incorporation of specific bioactive cues and independent manipulation of scaffold properties. The selective integrin binding of Scl2-2 was compared to more traditional collagen-modified PEG hydrogels to determine the effect of integrin binding on cell behavior. Protein functionalization density, protein concentration, and substrate modulus were independently tuned with both Scl2-2 and collagen to determine the effect of each variable on EC adhesion, spreading, and migration. The findings here demonstrate that increasing substrate modulus, decreasing functionalization density, and increasing protein concentration can be utilized to increase EC adhesion and migration. Additionally, PEG-Scl2-2 hydrogels had higher migration speeds and proliferation over 1 week compared with PEG-collagen gels, demonstrating that selective integrin binding can be used to enhance cell-material interactions. Overall, these studies contribute to the understanding of the effects of matrix cues on EC interactions and demonstrate the strong potential of PEG-Scl2-2 hydrogels to promote endothelialization of blood-contacting devices.

Tu1043 Low Volume Split-Dose Before Colonoscopy for Bowel Preparation: A Systematic Review and a Series of Meta-Analysis of Randomized Controlled Clinical Trials

Background and aim: An adequate colon cleaning is essential for a good quality colonoscopy and, among the others, the split regimens are those with the best cleaning rate. Low volume laxatives are better tolerated and accepted by patients than traditional PEG 4Lt with the same cleaning degree, but there is no consensus on which is the best in terms of bowel cleaning and at which regimen. Therefore, our aim was to assess the colon cleansing rate of different low volume laxatives given as split or non-split regimens. Material and methods: Published randomized clinical trials (1960-2013) comparing low volume split vs. non-split preparations in adults undergoing colonoscopy were selected using MEDLINE, the Cochrane Central Register of Controlled Trials, clinical trial.gov., ISI Web of Science. Search terms included “bowel”, “preparation”, “colon”, “cleaning” and “colonoscopy”. Results: From 104 initially screened abstracts, we retrieved 19 studies comparing sodium phosphate (NaP), Peg 2Lt, magnesium sulphate or sodium picosulphate for a total of 19 treatment arms (split group = 2316 patients; non-split = 2068 patients). A meta-analysis was performed on those studies comparing NaP vs. NaP (5 RCTs), Nap vs. Peg 2Lt (6 RCTs) and Peg 2Lt vs. Peg 2Lt (4 RCTs). Those laxatives, given as split preparations, were able to obtain a good to excellent cleaning rate in 90% of the patients while, given as non-split, reached the same degree in 67% to 73% of the patients with a rate difference (RD) ranging from 15% to 24% (table 1). Sodium phosphate and Peg 2Lt as split regimens were similar in terms of cleaning rate (respectively 91% and 90%). Other comparisons were between NaP vs. Mg sulphate (2 papers; RD=0.098; Cl 95%: −0.288–0.484; p=0.619), picosulphate vs picosulphate (1 paper; RD=0.27; Cl95%: 0.16–0.37; p<0.000) and PEG 2Lt vs picosulphate (1 paper; 83% vs. 73% Cl 95%; p=0.37).

Determination of thein vivodegradation mechanism of PEGDA hydrogels

Poly(ethylene glycol) (PEG) hydrogels are one of the most extensively utilized biomaterials systems due to their established biocompatibility and highly tunable properties. It is widely acknowledged that traditional acrylate-derivatized PEG (PEGDA) hydrogels are susceptible to slow degradation in vivo and are therefore unsuitable for long-term implantable applications. However, there is speculation whether the observed degradation is due to hydrolysis of endgroup acrylate esters or oxidation of the ether backbone, both of which are possible in the foreign body response to implanted devices. PEG diacrylamide (PEGDAA) is a polyether-based hydrogel system with similar properties to PEGDA but with amide linkages in place of the acrylate esters. This provides a hydrolytically-stable control that can be used to isolate the relative contributions of hydrolysis and oxidation to the in vivo degradation of PEGDA. Here we show that PEGDAA hydrogels remained stable over 12 weeks of subcutaneous implantation in a rat model while PEGDA hydrogels underwent significant degradation as indicated by both increased swelling ratio and decreased modulus. As PEGDA and PEGDAA have similar susceptibility to oxidation, these results demonstrate for the first time that the primary in vivo degradation mechanism of PEGDA is hydrolysis of the endgroup acrylate esters. Additionally, the maintenance of PEGDAA hydrogel properties in vivo indicates their suitability for long-term implants. These studies serve to elucidate key information about a widely used biomaterial system to allow for better implantable device design and to provide a biostable replacement option for PEGDA in applications that require long-term stability.

Synthesis of Cu3BiS3 and AgBiS2 crystallites with controlled morphology using hypocrellin template and their catalytic role in the polymerization of alkylsilane

Hypocrellins, photoactive compounds isolated from fungus, were first employed as non-surfactant templates in the synthesis of ternary chalcogenide Cu3BiS3 and AgBiS2 crystallites via a facile ethanol-thermal process. It was also found that the used templates, poly (vinylpyrrolidone) (PVP), poly (ethylene glycol) (PEG), and hypocrellins had strong effect on the morphology of synthesized Cu3BiS3 and AgBiS2 and their catalytic polymerization products of an alkylsilane, C18H37SiH3 with water. In particular, the orthorhombic phase of wittichenite Cu3BiS3 with multi-armed microrods morphology and the cubic Schapbachite and hexagonal phase Matildite AgBiS2 with flower-like morphology were obtained when hypocrellins were used as templates at 180 °C for 20 h. Although, the used templates seem to have little effect on the crystalline grain size, compared with traditional PVP and PEG templates, hypocrellins have exhibited better directing actions. Furthermore, the polymerization products over Cu3BiS3 and AgBiS2 templated by hypocrellins showed good replica of the morphologies before polymerization while the polymerization products over Cu3BiS3 and AgBiS2 templated by PVP and/or PEG exhibited significant morphology change.

Peg solitaire on graphs

There have been several papers on the subject of traditional peg solitaire on different boards. However, in this paper we consider a generalization of the game to arbitrary boards. These boards are treated as graphs in the combinatorial sense. We present necessary and sufficient conditions for the solvability of several well-known families of graphs. In the major result of this paper, we show that the cartesian product of two solvable graphs is likewise solvable. Several related results are also presented. Finally, several open problems related to this study are given.