Int J Nanomedicine. 2023 Mar 30:18:1615-1630. doi: 10.2147/IJN.S402418. eCollection 2023. Effects of PEG-Linker Chain Length of Folate-Linked Liposomal Formulations on Targeting Ability and Antitumor Activity of Encapsulated Drug Abstract Introduction: Ligand-conjugated liposomes are promising for the treatment of specific receptor-overexpressing cancers. However, previous studies have shown inconsistent results because of the varying properties of the ligand, presence of a polyethylene glycol (PEG) coating on the liposome, length of the linker, and density of the ligand. Methods: Here, we prepared PEGylated liposomes using PEG-linkers of various lengths conjugated with folate and evaluated the effect of the PEG-linker length on the nanoparticle distribution and pharmacological efficacy of the encapsulated drug both in vitro and in vivo. Results: When folate was conjugated to the liposome surface, the cellular uptake efficiency in folate receptor overexpressed KB cells dramatically increased compared to that of the normal liposome. However, when comparing the effect of the PEG-linker length in vitro, no significant difference between the formulations was observed. In contrast, the level of tumor accumulation of particles in vivo significantly increased when the length of the PEG-linker was increased. The tumor size was reduced by >40% in the Dox/FL-10K-treated group compared to that in the Dox/FL-2K- or 5K-treated groups. Discussion: Our study suggests that as the length of PEG-linker increases, the tumor-targeting ability can be enhanced under in vivo conditions, which can lead to an increase in the antitumor activity of the encapsulated drug. Keywords: PEG-linker length; PEGylated liposome; folate receptor; ligand-conjugated liposome. For more product information, please contact us at: US Tel: 1-844-782-5734 US Tel: 1-844-QUAL-PEG CHN Tel: 400-918-9898 Email: sales@sinopeg.com

Adv Mater. 2019 Jul;31(28):e1901580. doi: 10.1002/adma.201901580. Epub 2019 May 20. Tetra-PEG Based Hydrogel Sealants for In Vivo Visceral Hemostasis Abstract Medical sealant devices for in vivo hemostasis are far from satisfactory in the aged society. A major challenge is effective integration of quick hemorrhage control of the increased anticoagulated patients, high safety, and facile accessibility. Here, a well-defined ammonolysis-based Tetra-PEG hydrogel sealant is developed with rapid gelation speed, strong tissue adhesion, and high mechanical strength. Introduction of cyclized succinyl ester groups into a hydrogel matrix endows the sealant with fast degradable and controllably dissolvable properties. The hydrogel possesses outstanding hemostatic capabilities even under the anticoagulated conditions while displaying excellent biocompatibility and feasibility. These results reveal that the optimized hydrogel may be a facile, effective, and safe sealant for hemorrhage control in vivo. Keywords: Tetra-PEG hydrogels; controllable dissolution; fast degradation; sealants; visceral hemostasis. Related products Abbreviation: Tetra-PEG For more product information, please contact us at: US Tel: 1-844-782-5734 US Tel: 1-844-QUAL-PEG CHN Tel: 400-918-9898 Email: sales@sinopeg.com

ACS Appl Mater Interfaces. 2016 May 25;8(20):12674-83. doi: 10.1021/acsami.6b03235. Epub 2016 May 16. Synthesis and Properties of Hemostatic and Bacteria-Responsive in Situ Hydrogels for Emergency Treatment in Critical Situations  Abstract Immediate hemorrhage control and infection prevention are pivotal for saving lives in critical situations such as battlefields, natural disasters, traffic accidents, and so on. In situ hydrogels are promising candidates, but their mechanical strength is often not strong enough for use in critical situations. In this study, we constructed three hydrogels with different amounts of Schiff-base moieties from 4-arm-PEG-NH2, 4-arm-PEG-NHS, and 4-arm-PEG-CHO in which vancomycin was incorporated as an antimicrobial agent. The hydrogels possess porous structures, excellent mechanical strength, and high swelling ratio. The cytotoxicity studies indicated that the composite hydrogel systems possess good biocompatibility. The Schiff bases incorporated improve the adhesiveness and endow the hydrogels with bacteria-sensitivity. The in vivo hemostatic and antimicrobial experiments on rabbits and pigs demonstrated that the hydrogels are able to aid in rapid hemorrhage control and infection prevention. In summary, vancomycin-loaded hydrogels may be excellent candidates as hemostatic and antibacterial materials for first aid treatment of the wounded in critical situations. Keywords: PEG; antibacteria; hemostasis; hydrogels; pH-responsive. Related products Abbreviation: 4-arm PEG-OH, 4-arm PEG-NH2 For more product information, please contact us at: US Tel: 1-844-782-5734 US Tel: 1-844-QUAL-PEG CHN Tel: 400-918-9898 Email: sales@sinopeg.com

Synthesis and characterization of well-defined PAA–PEG multi-responsive hydrogels by ATRP and click chemistry https://doi.org/10.1039/C4RA09438G Abstract Multi-responsive poly(acrylic acid)–poly(ethylene glycol) (PAA–PEG) hydrogels with well-defined crosslinking structures were synthesized using atom transfer radical polymerization (ATRP) and copper-catalyzed 1,3-dipolar azide-alkyne cycloaddition (CuAAC) techniques. The well-defined PAA–PEG hydrogels with different degrees of crosslinking were produced from controlling the molecular weight of the PAA and PEG chains. The prepared multi-responsive hydrogels exhibit regular physical and mechanical properties by adjusting the pH and Ca2+ ion secondary crosslinking. With increasing pH, the swelling ratio of the well-defined multi-responsive PAA–PEG hydrogels increased remarkably. Furthermore, the well-defined PAA–PEG hydrogels with Ca2+ secondary crosslinking possessed a significantly higher crosslinking density as reflected by the lower swelling ratio, higher storage modulus, higher electrical conductivity and thermal stability. An in vitro cell viability assay also indicated that well-defined multi-responsive PAA–PEG hydrogels are biocompatible and have potential for implantable biomaterials. Related products Abbreviation: 4-arm-PEG For more product information, please contact us at: US Tel: 1-844-782-5734 US Tel: 1-844-QUAL-PEG CHN Tel: 400-918-9898 Email: sales@sinopeg.com

Synthesis and characterization of PLGA nanoparticle/4-arm-PEG hybrid hydrogels with controlled porous structures DOI https://doi.org/10.1039/C6RA08404D Abstract Controlled porous structures, adjustable surface properties and good mechanical properties are essential for hydrogels in promoting cell adhesion and growth.  In this work, we developed four armed poly(ethylene glycol) (4-arm-PEG) hydrogels crosslinked by poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs).  Branched polyethyleneimine (b-PEI) was employed for aminolysis of PLGA to engineer 300, 530 and 1000 nm NPs with a nitrogen contents of 11.7%, 9.4% and 9.7%.  Hybrid hydrogels were formed by crosslinking amino-packed NPs with polymeric chains of 4-arm-PEG-NHS.  By manipulating the NP and PEG contents as well as the NP sizes, the pore sizes could be tailored from 10–20 μm to 20–40 μm and 100–200 μm, and the maximal compressive strength could be optimized to 0.37 MPa.  Cytotoxicity trials indicated the hydrogels were almost non-toxic and biocompatible.  Cell adhesion evaluation testified higher amino contents and a smaller proportion of PEG led to more cell attachment.  These results demonstrated that this kind of hybrid hydrogel may be a suitable candidate for further biomedical applications in tissue engineering. Related products Abbreviation: 4-arm-PEG-NHS For more product information, please contact us at: US Tel: 1-844-782-5734 US Tel: 1-844-QUAL-PEG CHN Tel: 400-918-9898 Email: sales@sinopeg.com

Journal of Molecular Catalysis B: Enzymatic Volume 111, January 2015, Pages 36-42 Site-directed modification of genetically engineered Proteus sp. lipase K107 variants with a polyethylene glycol derivative Highlights •We report a novel method for site-directed PEGylation of protein. •Linear mPEGs of various sizes were functionalized via dopamine. •PEG derivates were used for site-specific PEGylation of enzyme with a single Cys residue. •The PEGylated enzymes maintained their secondary structures and activities, which was higher in low molecular mass PEG conjugates. •Conjugates with the site of polymer coupling near the catalytic centre were more stable. Abstract The covalent attachment of PEG to target proteins, known as PEGylation, has broad biomedical and biotechnological applications. Particularly, site-specific PEGylation is widely used owing to its unique properties of preserving bioactivity, improving the stability of conjugated proteins, and achieving a high degree of homogeneity. In this work, linear mPEGs of various sizes (MW = 5, 12, and 20 kDa) were functionalized via dopamine and used for site-specific PEGylation of Proteus sp. lipase K107 derivatives with a single Cys residue introduced by site-directed mutagenesis on the solvent-accessible surface of the protein. The specificity of conjugation was verified by SDS-PAGE and MALDI-TOF mass spectrometry, and the secondary structures of the conjugates were verified by circular dichroism. PEGylated enzymes retained their activity, which was higher in low molecular mass PEG conjugates. Importantly, both pH and thermal stability of enzymes were enhanced by PEGylation, especially at basic pH and above room temperature. Moreover, conjugates with the site of polymer coupling near the catalytic centre were more stable. These results demonstrate a novel, efficient method of site-specific protein modification via catechol-functionalized PEG that could potentially be applied to other enzymes. Related products Abbreviation: mPEGs For more product information, please contact us at: US Tel: 1-844-782-5734 US Tel: 1-844-QUAL-PEG CHN Tel: 400-918-9898 Email: sales@sinopeg.com

DOI:10.1021/acs.macromol.9b01654 Shear Modulus Dependence of the Diffusion Coefficient of a Polymer Network Published 10 December 2019 Dynamics of a polymer gel network is described by the theory proposed by Tanaka, Hocker, and Benedek (THB) that gives the diffusion coefficient of a polymer network (D=K+43Gf). Here, K is the osmotic bulk modulus, G is the shear modulus, and f is the friction coefficient between the polymer network and the solvent. Although several experimental studies investigated the dynamics of a polymer gel network, the THB theory has yet to be quantitatively validated. In this study, we quantitatively validate the THB theory by comparing D and G of Tetra-poly(ethylene glycol) gels measured by dynamic light scattering and dynamic viscoelastic measurement. The THB theory well described the linear increase in D with increasing G and gave K and f from the slope and the intercept. The gel network structural parameter dependences of the given K and f were well explained by the scaling laws. These results suggest that the THB theory is almost valid. Related products Abbreviation: Tetra-PEG-MA, Tetra-PEG-SH For more product information, please contact us at: US Tel: 1-844-782-5734 US Tel: 1-844-QUAL-PEG CHN Tel: 400-918-9898 Email: sales@sinopeg.com

ArticleDecember 31, 2015 Preparation of a High-Strength Hydrogel with Slidable and Tunable Potential Functionalization Sites Abstract A hydrogel with tunable potential functionalization sites has been successfully prepared. As potential functionalization sites, (2-hydroxypropyl)-α-CDs (Hy-α-CDs) were introduced into the network of tetrahedron-like poly(ethylene glycol) (tetra-PEG) gel through supramolecular chemistry. In the stage of complexation, poly-pseudo-rotaxane consisting of tetra-PEG macromonomer and Hy-α-CD formed in pregel solution. The dynamic complexation process and the structure of the poly-pseudo-rotaxane were investigated by NMR experiment. In the stage of gelation, some cross-linking reactions were completed through click chemistry. The structures and mechanical properties of the resultant hydrogels were characterized by ATR-FTIR, XPS, SEM, and compression test in detail. The number of Hy-α-CD introduced into the hydrogel is related closely to the structure of the poly-pseudo-rotaxane and can be controlled easily by tuning the feed ratio. Anthracene as an example of function was introduced into the hydrogel through Hy-α-CD to preliminarily demonstrate the validity of the potential functionalization site in the last, and the hydrogel also has the capacity for further diverse functionalization. Related products Abbreviation: Tetrahydroxyl-terminated PEG (THPEG) For more product information, please contact us at: US Tel: 1-844-782-5734 US Tel: 1-844-QUAL-PEG CHN Tel: 400-918-9898 Email: sales@sinopeg.com