Development of Soft Wrinkled Micropatterns on the Surface of 3D-Printed Hydrogel-Based Scaffolds via High-Resolution Digital Light Processing

The preparation of sophisticated hierarchically structured and cytocompatible hydrogel scaffolds is presented. For this purpose, a photosensitive resin was developed, printability was evaluated, and the optimal conditions for 3D printing were investigated. The design and fabrication by additive manufacturing of tailor-made porous scaffolds were combined with the formation of surface wrinkled micropatterns. This enabled the combination of micrometer-sized channels (100-200 microns) with microstructured wrinkled surfaces (1-3 μm wavelength). The internal pore structure was found to play a critical role in the mechanical properties. More precisely, the TPMS structure with a zero local curvature appears to be an excellent candidate for maintaining its mechanical resistance to compression stress, thus retaining its structural integrity upon large uniaxial deformations up to 70%. Finally, the washing conditions selected enabled us to produce noncytotoxic materials, as evidenced by experiments using AlamarBlue to follow the metabolic activity of the cells.

Promising Gene Delivery Properties of Polycations Based on 2-(N,N-dimethylamino)ethyl Methacrylate and Polyethylene Glycol Monomethyl Ether Methacrylate Copolymers

Cationic copolymers based on 2-(N,N-dimethylamino)ethyl methacrylate and polyethylene glycol monomethyl ether (pDMAEMA-co-PEO) with different molecular weights have been synthesized. Their physicochemical properties were studied by NMR spectroscopy, sedimentation, and potentiometric titration. According to the data of potentiometric titration for the synthesized pegylated cationic copolymers, the apparent dissociation constants were determined in the pH range from 4.5 to 8.5. The physicochemical properties of interpolyelectrolyte complexes of these polycations with circular DNA (IPEC DNA) were also studied by dynamic light scattering, electrophoretic mobility, and TEM methods. It has been established that the diameter and electrokinetic potential (ζ-potential) of interpolyelectrolyte complexes can be varied over a wide range (from 200 nm to 1.5 μm and from -25 mV to +30 mV) by changing the ratio of oppositely charged ionizable groups in pegylated cationic copolymers and DNA, as well as by regulating medium pH. The resistance of the IPEC DNA/polycation complex to the action of nucleases was studied by electrophoresis in agarose gel; the cytotoxic effect of the polymers in vitro, and the efficiency of penetration (transfection) of IPEC DNA with PDMAEMA-co-PEO-polycations into eukaryotic cells of a cell line derived from human embryonic kidneys HEK 293 in vitro.

Structural behavior of amphiphilic polyion complexes interacting with saturated lipid membranes investigated by coarse-grained molecular dynamic simulations

Neutral polyelectrolyte complexes (PECs) made from an amphiphilic multiblock copolymer of type (A_nB_n)_m and an oppositely charged polyion and interacting with a dipalmitoylphosphatidylcholine (DPPC) lipid membrane.

Stimuli-Responsive Poly( N-Vinyllactams) with Glycidyl Side Groups: Synthesis, Characterization, and Conjugation with Enzymes

Herein we report the synthesis of new reactive stimuli-responsive polymers by RAFT copolymerization of glycidyl methacrylate and three cyclic N-vinyllactam derivatives. The copolymerization process was thoroughly investigated and the influence of the steric hindrance originating from the monomer structure of cyclic N-vinyllactams on the polymerization process and the properties of obtained copolymers were studied. A series of water-soluble copolymers with variable chemical composition, controlled molecular weight and narrow dispersity ( Đ) were synthesized and their properties are systematically investigated. Experimentally determined cloud points for different copolymers in aqueous solutions indicate shift of lower critical solution temperature (LCST) to lower values with the increase of GMA content in copolymers and increase of the lactam ring size. The obtained reactive stimuli-responsive copolymers can be efficiently used for encapsulation of cellulase in water-in-oil emulsions forming biohybrid nanogels. The enzymes entrapped in nanogels demonstrated significantly improved resistance against harsh store conditions, chaotropic agents, and organic solvents.

Nanotechnology in Glycomics: Applications in Diagnostics, Therapy, Imaging, and Separation Processes

This review comprehensively covers the most recent achievements (from 2013) in the successful integration of nanomaterials in the field of glycomics. The first part of the paper addresses the beneficial properties of nanomaterials for the construction of biosensors, bioanalytical devices, and protocols for the detection of various analytes, including viruses and whole cells, together with their key characteristics. The second part of the review focuses on the application of nanomaterials integrated with glycans for various biomedical applications, that is, vaccines against viral and bacterial infections and cancer cells, as therapeutic agents, for in vivo imaging and nuclear magnetic resonance imaging, and for selective drug delivery. The final part of the review describes various ways in which glycan enrichment can be effectively done using nanomaterials, molecularly imprinted polymers with polymer thickness controlled at the nanoscale, with a subsequent analysis of glycans by mass spectrometry. A short section describing an active glycoprofiling by microengines (microrockets) is covered as well.

Cleavage of macromolecular RAFT chain transfer agents by sodium azide during characterization by aqueous GPC

Accurate and reliable analysis of polymers by GPC is vital in the field of controlled radical polymerisation.

Influence of Block versus Random Monomer Distribution on the Cellular Uptake of Hydrophilic Copolymers

The use of polymers has revolutionized the field of drug delivery in the past two decades. Properties such as polymer size, charge, hydrophilicity, or branching have all been shown to play an important role in the cellular internalization of polymeric systems. In contrast, the fundamental impact of monomer distribution on the resulting biological properties of copolymers remains poorly studied and is always only investigated for biologically active self-assembling polymeric systems. Here, we explore the fundamental influence of monomer distribution on the cellular uptake of nonaggregating and biologically passive copolymers. Reversible addition-fragmentation chain-transfer (RAFT) polymerization was used to prepare precisely defined copolymers of three hydrophilic acrylamide monomers. The cellular internalization of block copolymers was compared with the uptake of a random copolymer where monomers are statistically distributed along the chain. The results demonstrate that monomer distribution in itself has a negligible impact on copolymer uptake.