The influence of covalently linked and free polyethylene glycol on the structural and release properties of rhBMP-2 loaded microspheres

Dual-source dual-power electrospinning and characteristics of multifunctional scaffolds for bone tissue engineering

“…To determine the distribution of rhBMP-2 within F1 fibers, RhB-labeled rhBMP-2 was used in formulating emulsions for electrospinning, and the fluorescence signals emitted by RhB-labeled rhBMP-2 in resultant F1 fibers were detected under fluorescence microscopy. The labeling of rhBMP-2 by RhB followed Lochmann et al’ protocol [33] and the emulsions prepared had the same compositions as those with non-labeled rhBMP-2. Because the diameters of fibers in F1 scaffolds obtained through normal emulsion electrospinning were far too small for investigating rhBMP-2 distribution under the fluorescence microscope, much thicker fibers with diameters around 30 μm were electrospun and collected on cover slips for fluorescence microscopy.…”

PLA-b-PEG/magnetite hyperthermic agent prepared by Ugi four component condensation

“…The surface structure of all microspheres possesses large pores, which probably influence the amount of PEG linked by UFCC. The ability of PEG to form small pores in the surfaces of the microspheres was reported for microparticles based on blends of PLGA/PLA and PEG and also applies to microparticles composed of diblock polymer [79]. During the precipitation step, the PEG branches of the diblock copolymer orientated toward the internal and surrounding aqueous phase and formed a sponge-like structure [80].…”

Growth Factor-Loaded Microparticles for Tissue Engineering: The Discrepancies of In Vitro Characterization Assays

“…A similar result was previously observed by Lochmann et al where one single freeze/thaw cycle caused a loss of about one third in ELISA detection of BMP-2, clearly suggesting that the freezing step was a significant issue. 26 Additionally, even during assays, which are gentler than the extraction methods, such as in vitro release assays in saline buffer, in the absence of any surrounding cells, which would otherwise rapidly utilize the released GFs/signaling molecules, these molecules are invariably and rapidly adsorbed back to the dissolving polymer matrix, in turn biasing the release results. Surfactants are commonly used in this respect by effectively raising the energy barrier for intermolecular interactions between proteins by surrounding them with their hydrophilic ends.…”

“…In terms of reducing denaturation, electrospraying holds great potential considering the limited exposure to organic solvents and the possibility to use dry encapsulation. 22 Although sugars blended into the polymer matrix have been widely used for improving protein bioactivity in traditional encapsulation techniques, 4,5,[14][15][16]26 to our knowledge, no studies have investigated their use in electrospraying and hence this possibility represented an avenue of interest.…”