PEG Incorporation Research Articles

Reduction of Non-Specific Protein Adsorption Using Poly(ethylene) Glycol (PEG) Modified Polyacrylate Hydrogels In Immunoassays for Staphylococcal Enterotoxin B Detection

Three PEG molecules (PEG-methacrylate, -diacrylate and -dimethacrylate) were incorporated into galactose-based polyacrylate hydrogels and their relative abilities to reduce non-specific protein adsorption in immunoassays were determined. Highly crosslinked hydrogels containing amine-terminated functionalities were formed and used to covalently attach antibodies specific for staphylococcal enterotoxin B (SEB). Patterned arrays of immobilized antibodies in the PEG-modified hydrogels were created with a PDMS template containing micro-channels for use in sandwich immunoassays to detect SEB. Different concentrations of the toxin were applied to the hydrogel arrays, followed with a Cy3-labeled tracer antibody specific for the two toxins. Fluorescence laser scanning confocal microscopy of the tracer molecules provided both qualitative and quantitative measurements on the detection sensitivity and the reduction in non-specific binding as a result of PEG incorporation. Results showed the PEG-modified hydrogel significantly reduced non-specific protein binding with a detection limit for SEB of 1 ng/mL. Fluorescence signals showed a 10-fold decrease in the non-specific binding and a 6-fold increase in specific binding of SEB.

Nanocrystalline scandia-doped zirconia (ScSZ) powders prepared by a glycine–nitrate solution combustion route

Nanocrystalline scandia doped zirconia (ScSZ) powders were synthesized by a solution combustion route using glycine, zirconyl nitrate and scandia as the starting materials. The properties of the as-synthesized powders are strongly influenced by the molar ratio of glycine-to-nitrate ( g/ n), where with the g/ n ratio increasing from 0.14 to 1.12, the crystallite sizes of the powders decrease from 15.9 to 7.9 nm. 11ScSZ powders of specific surface areas up to 29 m 2/g can be obtained through adjusting the initial g/ n to 0.56 or greater. Incorporation of an appropriate amount of PEG dispersant into the starting solution can reduce the tendency of hard agglomeration formation. Investigations showed that powders from start solutions with the PEG incorporation have better sinterability than that of powders without the initial PEG incorporation, e.g., with the incorporation of 1.5 wt.% PEG dispersant in the starting solution, the resultant powders can be sintered to over 96% of theoretical density at 1200 °C, which is nearly 100 °C lower than that of powders without the initial PEG incorporation.

TIBIAL CORTICAL BONE PEG FIXATION IN OSTEOCHONDRITIS DISSECANS OF THE KNEE

Ten knees in nine patients with large, symptomatic osteochondritis dissecans lesions of the knee were treated by cortical bone peg fixation. The follow-up time averaged 2.9 years (range, 0.9-6.6 years). The average age was 19.5 years (range, 15-33 years). The knees were evaluated and rated clinically and roentgenographically. Magnetic resonance (MR) imaging of nine knees was obtained at the follow-up examination to evaluate lesion and bone peg incorporation, evidence of lesion loosening, and the articular cartilage. Eight good to excellent, one fair, and one poor result were obtained clinically. MR imaging showed 33% of knees had poor lesion cartilage and 44% had partial or poor lesion incorporation possibly consistent with loosening. Complications included four partial defect healings, one tibial donor graft-site fracture, and one bone peg loosening. Four symptomatic knees had follow-up arthroscopy at an average of 1.8 years postsurgery and findings included four loose bodies, one loose peg, one meniscal tear, and one symptomatic hypertrophic synovium. MR imaging was a useful tool in evaluating lesion stability, articular cartilage quality, lesion and bone peg incorporation, the menisci, and cruciate ligaments. Bone peg fixation of large osteochondritis dissecans defects of the knee offers a physiologic approach to treatment of this lesion in nearly skeletally mature or skeletally mature patients.

Tibia1 Cortical Bone Peg Fixation in Osteochondritis Dissecans of the Knee

Ten knees in nine patients with large, symptomatic osteochondritis dissecans lesions of the knee were treated by cortical bone peg fixation. The follow-up time averaged 2.9 years (range, 0.9-6.6 years). The average age was 19.5 years (range, 15-33 years). The knees were evaluated and rated clinically and roentgenographically. Magnetic resonance (MR) imaging of nine knees was obtained at the follow-up examination to evaluate lesion and bone peg incorporation, evidence of lesion loosening, and the articular cartilage. Eight good to excellent, one fair, and one poor result were obtained clinically. MR imaging showed 33% of knees had poor lesion cartilage and 44% had partial or poor lesion incorporation possibly consistent with loosening. Complications included four partial defect healings, one tibial donor graft-site fracture, and one bone peg loosening. Four symptomatic knees had follow-up arthroscopy at an average of 1.8 years postsurgery and findings included four loose bodies, one loose peg, one meniscal tear, and one symptomatic hypertrophic synovium. MR imaging was a useful tool in evaluating lesion stability, articular cartilage quality, lesion and bone peg incorporation, the menisci, and cruciate ligaments. Bone peg fixation of large osteochondritis dissecans defects of the knee offers a physiologic approach to treatment of this lesion in nearly skeletally mature or skeletally mature patients.