0000000000004307
AUTHOR
Matthias Maier
Inverse Thermogelation of Aqueous Triblock Copolymer Solutions into Macroporous Shear-Thinning 3D Printable Inks
Amphiphilic block copolymers that undergo (reversible) physical gelation in aqueous media are of great interest in ditIerent areas including drug delivery, tissue engineering, regenerative medicine, and biofabrication. We investigated a small library of ABA-type triblock copolymers comprising poly(2-methyl-2-oxazoline) as the hydrophilic shell A and different aromatic poly(2-oxazoline)s and poly(2-oxazine)s cores B in an aqueous solution at different concentrations and temperatures. Interestingly, aqueous solutions of poly(2-methyl-2-oxazoline)-block-poly(2-phenyl-2-oxazine)-block-poly(2-methyl-2-oxazoline) (PMeOx-b-PPheOzi-b-PMeOx) undergo inverse thermogelation below a critical temperatur…
Transvalvular enteroscopy using a mother-baby endoscope system: a new approach to the distal ileum.
In the past decade various endoscopes have been developed to examine the small bowel, with two principal procedures established: sonde-type enteroscopy and push-type enteroscopy. The main indication is gastrointestinal bleeding of obscure origin. Push-type enteroscopy has proved itselfto be useful for the investigation ofdiseases of the small intestine. 1 The mean instrumental insertion length published by different working groups varied between 50 and 90 cm past the ligament of Trei tzfl 2 The small bowel examination area is limited to the jejunum. The alternative method is sonde-type enteroscopy that allows an insertion length of 140 (30 to 200) cm. 3, 4 Disadvantages of this type of ente…
Management of retained bile duct stones: a prospective open trial comparing extracorporeal and intracorporeal lithotripsy.
Abstract Background: Endoscopic management of common bile duct stones has become the approach of choice, especially in patients with high surgical risk. Problems are encountered if there are large stones or a duct stenosis. For these difficult stones, shock wave technology serves as an alternative to surgical intervention. Methods: A total of 125 patients with common bile duct stones in whom conventional endoscopic treatment had failed were selected and treated either by extracorporeal piezoelectric lithotripsy (ESWL, n=79) or intracorporeal electrohydraulic lithotripsy (EHL, n=46). The average age of our patients was 70 years. Results: In the ESWL group visualization of the stones by ultra…
An Inverse Thermogelling Bioink Based on an ABA-Type Poly(2-oxazoline) Amphiphile
Hydrogels are key components in several biomedical research areas such as drug delivery, tissue engineering, and biofabrication. Here, a novel ABA-type triblock copolymer comprising poly(2-methyl-2-oxazoline) as the hydrophilic A blocks and poly(2-phenethyl-2-oxazoline) as the aromatic and hydrophobic B block is introduced. Above the critical micelle concentration, the polymer self-assembles into small spherical polymer micelles with a hydrodynamic radius of approx 8-8.5 nm. Interestingly, this specific combination of hydrophilic and hydrophobic aromatic moieties leads to rapid thermoresponsive inverse gelation at polymer concentrations above a critical gelation concentration (20 wt %) into…