Nanoscale. 2015 Mar 12;7(12):5249-61. doi: 10.1039/c4nr07591a. Core-shell hybrid upconversion nanoparticles carrying stable nitroxide radicals as potential multifunctional nanoprobes for upconversion luminescence and magnetic resonance dual-modality imaging Chuan Chen 1, Ning Kang, Ting Xu, Dong Wang, Lei Ren, Xiangqun Guo Abstract Nitroxide radicals, such as 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) and its derivatives, have recently been used as contrast agents for magnetic resonance imaging (MRI) and electron paramagnetic resonance imaging (EPRI). However, their rapid one-electron bioreduction to diamagnetic N-hydroxy species when administered intravenously has limited their use in in vivo applications. In this article, a new approach of silica coating for carrying stable radicals was proposed. A 4-carboxyl-TEMPO nitroxide radical was covalently linked with 3-aminopropyl-trimethoxysilane to produce a silanizing TEMPO radical. Utilizing a facile reaction based on the copolymerization of silanizing TEMPO radicals with tetraethyl orthosilicate in reverse microemulsion, a TEMPO radicals doped SiO2 nanostructure was synthesized and coated on the surface of NaYF4:Yb,Er/NaYF4 upconversion nanoparticles (UCNPs) to generate a novel multifunctional nanoprobe, PEGylated UCNP@TEMPO@SiO2 for upconversion luminescence (UCL) and magnetic resonance dual-modality imaging. The electron spin resonance (ESR) signals generated by the TEMPO@SiO2 show an enhanced reduction resistance property for a period of time of up to 1 h, even in the presence of 5 mM ascorbic acid. The longitudinal relaxivity of PEGylated UCNPs@TEMPO@SiO2 nanocomposites is about 10 times stronger than that for free TEMPO radicals. The core-shell NaYF4:Yb,Er/NaYF4 UCNPs synthesized by this modified user-friendly one-pot solvothermal strategy show a significant enhancement of UCL emission of up to 60 times more than the core NaYF4:Yb,Er. Furthermore, the PEGylated UCNP@TEMPO@SiO2 nanocomposites were further used as multifunctional nanoprobes to explore their performance in the UCL imaging of living cells and T1-weighted MRI in vitro and in vivo. Related products Abbreviation: mPEG-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

ACS Appl Mater Interfaces. 2017 Jan 25;9(3):2205-2212.  doi: 10.1021/acsami.6b15364.  Epub 2017 Jan 10. Construction of Tough, in Situ Forming Double-Network Hydrogels with Good Biocompatibility Yazhong Bu 1 2, Hong Shen 1, Fei Yang 1 2, Yanyu Yang 1 2, Xing Wang 1, Decheng Wu 1 2 Abstract Hydrogels are required to have high mechanical properties, biocompatibility, and an easy fabrication process for biomedical applications.  Double-network hydrogels, although strong, are limited because of the complicated preparation steps and toxic materials involved.  In this study, we report a simple method to prepare tough, in situ forming polyethylene glycol (PEG)-agarose double-network (PEG-agarose DN) hydrogels with good biocompatibility.  The hydrogels display excellent mechanical strength.  Because of the easily in situ forming method, the resulting hydrogels can be molded into any form as needed.  In vitro and in vivo experiments illustrate that the hydrogels exhibit satisfactory biocompatibility, and cells can attach and spread on the hydrogels.  Furthermore, the residual amino groups in the network can also be functionalized for various biomedical applications in tissue engineering and cell research. Keywords: PEG;  agarose;  biocompatible;  double network;  hydrogels. Related products Abbreviation: 4-arm-PEG-NHS Abbreviation: 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

Colloids Surf B Biointerfaces. 2018 May 1:165:144-149. doi: 10.1016/j.colsurfb.2018.02.032. Epub 2018 Feb 15. Branched polyrotaxane hydrogels consisting of alpha-cyclodextrin and low-molecular-weight four-arm polyethylene glycol and the utility of their thixotropic property for controlled drug release Juan Wang 1, Geoffrey S Williamson 2, Hu Yang 3 Abstract In this work, we developed a new class of branched polyrotaxane hydrogel made of 4-arm polyethylene glycol (4-PEG) and α-cyclodextrin (α-CD) using supramolecular host-guest interactions as a cross-linking strategy. Because of the dynamic nature of the non-covalent host-guest cross-linking, the resulting supramolecular α-CD/4-PEG hydrogels show thixotropic behavior and undergo a reversible gel-sol transition in response to shear stress change. We loaded the antiglaucoma drug brimonidine into the α-CD/4-PEG gel and found the drug release kinetics was controlled by shear stress. This thixotropic shear thinning property makes the supramolecular hydrogels highly attractive in drug delivery applications and suitable for preparation of injectable drug formulations. Keywords: Branched PEG; Glaucoma; Host-guest interaction; Supramolecular; Thixotropic. Related products Abbreviation: 4-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

Biomaterials. 2019 Feb:192:392-404.   doi: 10.1016/j.biomaterials.2018.10.047.   Epub 2018 Nov 2. A PEG-Lysozyme hydrogel harvests multiple functions as a fit-to-shape tissue sealant for internal-use of body Haoqi Tan 1, Dawei Jin 2, Xue Qu 3, Huan Liu 1, Xin Chen 1, Meng Yin 4, Changsheng Liu 5 Abstract In situ formation of surgical sealants to stop internal fluids leakage is more attractive compared to the traditional suture or staple.   However, commercial sealants have weak points in tissue adhesive, cell affinity, antibacterial etc., which make them remain suboptimal for internal use of body.   It is required to develop multifunctional sealants that can meet clinical needs.   Herein, a PEG-lysozyme (LZM) injectable sealant composed of 4-arm-PEG and lysozyme was developed.   Lysozyme offers free amine groups to rapidly cross link with PEG.   The hydrogel can tightly adhere to tissues and provide good mechanics to withstand high pressure.   Moreover, lysozyme innately confers antibacterial and cell affinity on the hydrogel that are usually lacking in marketed sealants.   The hydrogel is easily operated to seal gas or blood leakage in a rabbit trachea and artery defect.   Moreover, it can close the transmural left ventricular wall defect on a beating heart.   The traumatic organ functions completely recovered postoperatively.   Considering the good biocompatibility and the simple fabrication process, the PEG-LZM hydrogel is promising to clinical transformation.   More broadly, our work indicates that nature-occurring molecules are versatile building blocks for construction of materials and confer functions, which represents a simple tragedy to develop advanced functional biomaterials. Keywords: 4-Arm-Poly ethylene glycol;   Antimicrobial;   Cell attachment;   Injectable hydrogel;   Lysozyme;   Tissue sealing. 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

Mol. Pharmaceutics 2016, 13, 9, 3308–3317 August 12, 2016 https://doi.org/10.1021/acs.molpharmaceut.6b00619 Comparison of Two Approaches for the Attachment of a Drug to Gold Nanoparticles and Their Anticancer Activities Yingjie Fu†, Qishuai Feng‡, Yifan Chen‡, Yajing Shen‡, Qihang Su‡, Yinglei Zhang‡, Xiang Zhou*†, and Yu Cheng*‡ Abstract Drug attachment is important in drug delivery for cancer chemotherapy. The elucidation of the release mechanism and biological behavior of a drug is essential for the design of delivery systems. Here, we used a hydrazone bond or an amide bond to attach an anticancer drug, doxorubicin (Dox), to gold nanoparticles (GNPs) and compared the effects of the chemical bond on the anticancer activities of the resulting Dox-GNPs. The drug release efficiency, cytotoxicity, subcellular distribution, and cell apoptosis of hydrazone-linked HDox-GNPs and amide-linked SDox-GNPs were evaluated in several cancer cells. HDox-GNPs exhibited greater potency for drug delivery via triggered release comediated by acidic pH and glutathione (GSH) than SDox-GNPs triggered by GSH alone. Dox released from HDox-GNPs was released in lysosomes and exerted its drug activity by entering the nuclei. Dox from SDox-GNPs was mainly localized in lysosomes, significantly reducing its efficacy against cancer cells. In addition, in vivo studies in tumor-bearing mice demonstrated that HDox-GNPs and SDox-GNPs both accumulate in tumor tissue. However, only HDox-GNPs enhanced inhibition of subcutaneous tumor growth. This study demonstrates that HDox-GNPs display significant advantages in drug release and antitumor efficacy. KEYWORDS: gold nanoparticle, doxorubicin, drug delivery, anticancer activity Related products Abbreviation: MeO-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

Bioact Mater. 2019 Apr 12:4:160-166. doi: 10.1016/j.bioactmat.2019.03.002. eCollection 2019 Dec. Synergistic therapy of magnetism-responsive hydrogel for soft tissue injuries Lining Zhang 1, Xiuqin Zuo 1, Shengjie Li 1, Mi Sun 2, Huimin Xie 1, Kai Zhang 1, Jikun Zhou 1, Liyun Che 1, Junxuan Ma 3 4, Zishan Jia 1, Fei Yang 2 5 Abstract Soft tissue injury is very common and associated with pain, tissue swelling and even malformation if not treated on time. Treating methods include cryotherapy, electrical therapy, ultrasound therapy and anti-inflammatory drug, but none of them is completely satisfying. In this work, for a better therapeutic effect, drug therapy and pulsed electromagnetic field (PEMF) therapy were combined. We constructed a drug delivery system using the tetra-PEG/agar hydrogel (PA). By incorporating Fe3O4 NPs into the hydrogel network, a magnetism-responsive property was achieved in the system. The cytotoxicity and in vivo study showed a good biocompatibility of the PA/Fe3O4 hydrogel. A magnetism-controlled release was attained by the incorporation of Fe3O4. Finally, in vivo study showed a better performance of the DS-loaded PA/Fe3O4 compared with the commercially available DS ointment regarding the recovery of the injured soft tissue. Therefore, this magnetism-responsive hydrogel may represent a promising alternative to treat soft tissue injury. Keywords: Hydrogel; Magnetism-responsive; Tetra-PEG/agar; Tissue injury. Related products Abbreviation: Tetrazine-PEG-NH2 Abbreviation: Tetrazine-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

Biomater Sci. 2020 Jun 7;8(11):3138-3146. doi: 10.1039/d0bm00376j. Epub 2020 Apr 30. Long-term delivery of alendronate through an injectable tetra-PEG hydrogel to promote osteoporosis therapy Dawei Li 1, Jin Zhou, Mingming Zhang, Yuanzheng Ma, Yanyu Yang, Xue Han, Xing Wang Abstract Pharmacotherapy for hypercalcemia, which is mainly caused by osteoporosis, is an effective method to regulate the in vivo calcium equilibrium. From this perspective, the development of a minimally invasive gelling system for the prolonged local delivery of bisphosphonates has practical significance in the clinical therapy of bone osteoporosis. Here, a biocompatible and injectable hydrogel based on a uniform tetra-PEG network carrying a PEG-modified alendronate (ALN) prodrug for the localized elution and long-term sustained release of anti-osteoporotic small molecule drugs is reported. The obtained ALN-based tetra-PEG hydrogels exhibit rapid gel formation and excellent injectability, thereby allowing for the easy injection and consequent adaptation of hydrogels into the bone defects with irregular shapes, which promotes the ALN-based tetra-PEG hydrogels with depot formulation capacity for governing the on-demand release of ALN drugs and local reinforcement of bone osteoporosis at the implantation sites of animals. The findings imply that these injectable hydrogels mediate the optimized release of therapeutic cargoes and effectively promote in situ bone regeneration via minimally invasive procedures, which is effective for clinical osteoporosis therapy. Related products Abbreviation: Tetrazine-PEG-NH2 Abbreviation: Tetrazine-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

Publication Date:August 18, 2020 https://doi.org/10.1021/acs.macromol.0c01208 Selective Doping of Positive and Negative Spatial Defects into Polymer Gels by Tuning the Pregel Packing Conditions of Star Polymers Abstract Gels are giant single molecules that consist of a very large number (∼Avogadro’s number) of cross-linked nanometer-size polymer chains.   Unlike most low-molecular-weight compounds, the extensively cross-linked gel networks typically do not exhibit a well-defined structure.   In a previous study, we disproved this preconception and demonstrated that by applying suitable percolation conditions during the gelation process, a highly homogeneous gel with an ordered structure can be synthesized.   In the present study, we further demonstrate that by tuning the percolation conditions, stable polymer-rich or polymer-poor nanodefects can be selectively introduced in the gel network;   the controlled addition of such nanodefects has not been achieved before.   The successful introduction of nanodefects was confirmed using laser speckle tests, and their structures and dynamics were evaluated in Fourier space using static and dynamic scattering measurements.   While the addition of polymer-rich defects had a relatively little effect on the elastic modulus of gels, the addition of pores significantly lowered the elastic modulus, suggesting that substantial topological defects were introduced simultaneously when the packing ratio was low.   The controlled addition of such nanodefects may potentially modulate the structural, mechanical, optical, and mass transportation properties of the gels effectively, and thus serve as a new design strategy for gel materials. Related products Abbreviation: Tetrazine-PEG-NH2 Name: α-Tetrazine-ω-amino poly(ethylene glycol) 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