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Immunocytochemical Detection Systems
Published in Lars-Inge Larsson, Immunocytochemistry: Theory and Practice, 2020
Peters et al.271 used commercially available silica spheres for labeling antibodies (size ranges of 7 to 8, 13 to 14, and 22 to 25 nm were commercially available). The silica spheres of 13 to 14 nm were derivatized chemically to introduce reactive groups (amino or aldehyde group derivatized silica spheres, or IDSS). The silica core (Si02) of the spheres afforded useful electron density in TEM.271 Polyethyleneimine particles were suggested as immunoelectron microscopic tracers by Schurer et al.305 The polyethyleneimine structure incorporates multiple (primary, secondary, and tertiary) amino groups and polyethyleneimine polymers are available in the size range 600 to 60,000 daltons. Schurer et al.305 elected to use a polymer size of 30,000 to 40,000 daltons. In one set of experiments (colloid system), a colloidal suspension was obtained by 1% polyethyleneimine and 0.1% silver nitrate or gold chloride solution reduced by sodium borohydride or glutaraldehyde. This resulted in particles about 3 nm in diameter which, however, were unstable. In a second set of experiments Schurer et al.305 directly contrasted the polyethyleneimine particles (osmic acid or phosphotungstic acid). To my knowledge, direct immunoelectron microscopic use of polyethyleneimine has not yet been documented, although the polymer has some theoretically appealing characteristics.
Application of Bioresponsive Polymers in Drug Delivery
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Manisha Lalan, Deepti Jani, Pratiksha Trivedi, Deepa H. Patel
Bioreducible poly(amidoamine) with multiple disulfide linkages have been synthesized and investigated as nonviral gene vectors. The so formed polymers were stable in physiological pH but are rapidly degraded in reducing bioenvironment. The polymers are able to condense DNA with them and form positively charged nanocarriers sizing below 200 nm. They exhibit buffer capacities higher than polyethyleneimine which favors it for endosomal escape. In-vitro transfection efficiencies of the synthesized polymers were much higher than polyethyleneimine. They represent a good option for nontoxic, safe, and efficient nanocarriers for transfection of nucleic acids [157].
Measuring and Interpreting Polycation Adsorption
Published in E. Desmond Goddard, James V. Gruber, Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
E. Desmond Goddard, James V. Gruber
A factor linked to advantage (a) concerns the limited surface area of natural keratins: even for hair, the nominal value (see below) is only . For all of the above reasons, more (published) adsorption data in this field have been obtained by the radiotracer method than by any other—even though, for environmental reasons, use of the method has dwindled during the last decade. Polyethyleneimine
Surface modification of ureteral stents: development history, classification, function, and future developments
Published in Expert Review of Medical Devices, 2023
Kaiguo Xia, Xudong Shen, Xiaojie Ang, Bingbing Hou, Yang Chen, Kaiping Zhang, Zongyao Hao
In recent years, some scholars have studied grafting chemicals on the surface of ureteral stents to prevent stent encrustation and achieve better results. Polyethyleneimine (PEI) is a synthetic and nontoxic polymer containing a polycationic structure that comes from primary, secondary, and tertiary amino groups with antibacterial and antifouling properties. Gultekinoglu M [33,63]et al. covalently linked two different molecular weight PEI chains on the different surfaces of polyurethane (PU) by the “grafting to” approach to obtain a brush-like structure. Then, the PEI brush was alkylated with bromhexine to increase the cationic enhancement to the destruction of the bacterial membrane, and the experimental results showed that the surface crusting of the ureteral stent after PEI grafting was significantly reduced. Awonusi BO et al. [64] immobilized Hep/PLL-Cu nanoparticles on dopamine-coated polyurethane surfaces (PU/NPs) and found that the coated stent could inhibit Proteus mirabilis proliferation and biofilm formation, and reduced Ca and Mg salt deposition after in vitro and in vivo experiments.
Synapse topology and downmodulation events determine the functional outcome of anti-CD19 T cell-redirecting strategies
Published in OncoImmunology, 2022
Ángel Ramírez-Fernández, Óscar Aguilar-Sopeña, Laura Díez-Alonso, Alejandro Segura-Tudela, Carmen Domínguez-Alonso, Pedro Roda-Navarro, Luis Álvarez-Vallina, Belén Blanco
The lentiviral vectors pCCL-EF1α-BiTE19,28 containing the human kappa light chain signal peptide L1,32 the A3B1 scFv (VL-VH),33 a five-residue linker (G4S), the OKT3 scFv (VH-VL) 34 and a C-terminal polyHis tag, and pCCL-EF1-CAR19,33 encoding a second-generation (CD8-BBζ) anti-CD19 CAR (19-CAR),33 was used. To produce lentiviral particles, HEK293T cells were transfected with the transfer vector (pCCL-EF1α-BiTE19 or pCCL-EF1-CAR19) together with packaging plasmids. In brief, HEK293T cells (6 × 106) were plated 24 hours before transfection in 10 cm dishes. At the time of transfection, 6.9 μg transfer vector (pCCL-EF1α-BiTE19 or pCCL-EF1α-CAR19), 3.41 μg pMDLg/pRRE (Addgene, 12251), 1.7 μg pRSV-Rev (Addgene, 12253), and 2 μg envelope plasmid pMD2.G (Addgene, 12259) were diluted in serum-free DMEM. 35 μg linear polyethyleneimine (PEI) molecular weight 25,000 (Polysciences, 23966–1) was added to the mixture and incubated for 20 minutes at room temperature. After incubation, DNA-PEI complexes were added onto the cells cultured in 7 mL of complete DMEM. Media were replaced 4 hours later.
Synthesis and characterization of polyethyleneimine-terminated poly(β-amino esters) conjugated with pullulan for gene delivery
Published in Pharmaceutical Development and Technology, 2022
Atena Farahpour, Navid Ramezanian, Leila Gholami, Saeedeh Askarian, Arsham Banisadr, Reza Kazemi Oskuee
Pullulan is a linear glucosic polysaccharide with the chemical structure of {→6)-α-d-glucopyranosyl-(1→4)-α-d-glucopyranosyl-(1→4)-α-d-glucopyranosyl-(1→}n. Due to its properties such as non-toxicity, non-carcinogenic, non-mutagenic, non-immunogenic, and high flexibility in aqueous solutions, as well as biocompatibility and biodegradability, it has been investigated in different biomedical applications comprising of gene delivery, targeted drug delivery, and tissue engineering (Kaneo et al. 2001; Na and Bae 2002; Singh et al. 2008; Cheng et al. 2011; Prajapati et al. 2013). Moreover, gene delivery is the main field in which pullulan application is being explored. Another point which is mentioned in various studies in regard to pullulan benefits is that liver which consists of many asialglycoprotein receptors (ASGPRs) that could be used as a target for pullulan in liver targeting (Yamaoka et al. 1993; Na and Bae 2002; Weigel and Yik 2002; Mehvar 2003). Polyethyleneimine (PEI) has held great promise for gene delivery. In most cases, only the high molecular weight PEIs enable to form bind with nucleic acids and lead to a high gene transfection efficiency. However, high molecular weight PEIs because of their intense cytotoxicity are not a good option for gene delivery application. In this study, pBAE was exploited as the basic polymer for gene carrier development, and low molecular weight PEI (MW 1800 Da) acts as a cationic polymer modifier with low toxicity to improve the water solubility and charge of the basic polymer.