2 research outputs found
Coil Flow Inversion as a Route To Control Polymerization in Microreactors
Linear and branched polymers of 2-(dimethylamino)ethyl
methacrylate
(PDMAEMA) were synthesized in flow by atom transfer radical polymerization
(ATRP) and self-condensing vinyl copolymerization adapted to ATRP,
respectively, in capillary type stainless steel coiled tube (CT) microreactors.
Coil flow inversion (CFI) was introduced to achieve better mixing
and narrower residence time distributions during polymerization. This
strategy was adopted to improve control over macromolecular characteristics
and polymer architecture. Polydispersity index (PDI), as an overall
indicator of control over polymerization, was significantly lower
for CFI in the case of linear PDMAEMA, 1.39 compared to 1.53 for CT.
For branched polymers containing up to 10 mol % of inimer, a reduced
PDI was also obtained for CFI microreactor. As for the branching efficiency,
it was found to follow the following trend CFI > CT > batch
reactor
Interaction of Human Plasma Proteins with Thin Gelatin-Based Hydrogel Films: A QCM‑D and ToF-SIMS Study
In
the fields of surgery and regenerative medicine, it is crucial
to understand the interactions of proteins with the biomaterials used
as implants. Protein adsorption directly influences cell-material
interactions in vivo and, as a result, regulates, for example, cell
adhesion on the surface of the implant. Therefore, the development
of suitable analytical techniques together with well-defined model
systems allowing for the detection, characterization, and quantification
of protein adsorbates is essential. In this study, a protocol for
the deposition of highly stable, thin gelatin-based films on various
substrates has been developed. The hydrogel films were characterized
morphologically and chemically. Due to the obtained low thickness
of the hydrogel layer, this setup allowed for a quantitative study
on the interaction of human proteins (albumin and fibrinogen) with
the hydrogel by Quartz Crystal Microbalance with Dissipation Monitoring
(QCM-D). This technique enables the determination of adsorbant mass
and changes in the shear modulus of the hydrogel layer upon adsorption
of human proteins. Furthermore, Secondary Ion Mass Spectrometry and
principal component analysis was applied to monitor the changed composition
of the topmost adsorbate layer. This approach opens interesting perspectives
for a sensitive screening of viscoelastic biomaterials that could
be used for regenerative medicine