Narrowly distributed spherical poly(N-vinylcaprolactam) (PNVC) microgels were prepared by precipitation polymerization in water. The effect of both anionic (sodium dodecyl sulfate, SDS) and cationic (N-dodecylpyridinium bromide, DPB) surfactants on the swelling and shrinking of the microgels were investigated by laser light scattering (LLS). Our results showed that the microgels gradually shrank to the collapsed state when the temperature increased from 20 to ∼38 °C. The addition of anionic surfactant caused an extra swelling of the microgels and shifted the collapsing temperature higher, whereas the addition of cationic surfactant has different effects on the swelling and shrinking of the microgels prepared by using different initiators, depending on whether the decomposed fragments of the initiator are ionic or neutral. Our results clearly showed that the ionic groups introduced into polymer gels from the initiators should be taken into consideration in the study of the surfactant/gel interaction.

Thermosensitive polymers such as poly(N-isopropylacrylamide) (PNIPAM) have a lower critical solution temperature in water in a temperature range between 32 and 35 °C. Micro-and macrogels of such polymers show a temperature-controlled reversible swelling behavior. Therefore, they are of great interest for a variety of applications (e.g., the controlled drug delivery and accessibility of enzymes). Up to now such gels were prepared by covalent cross-linking. A new and promising route for the preparation of microgels down to the nanometer scale consists of the formation of polyelectrolyte complex particles between ionically modified thermosensitive polymers. The formation, structure, and temperature behavior of complexes between PNIPAM with differing contents of anionic and cationic groups was studied by viscometry and static and dynamic light scattering. The level of aggregation of such complexes increases with increasing mixing ratio, while the polymer concentration has only a marginal effect. The complexes were highly swollen at 25 °C and collapsed in a temperature range up to 50 °C, where the swelling-deswelling process is completely reversible. Even complexes between copolymers of higher contents of ionic groups (up to about 30%) and complexes between copolymers and pure polyelectrolytes showed a pronounced temperature dependence of the structural density. † Part of the special issue "Colloid Science Matured, Four Colloid Scientists Turn 60 at the Millennium".

No abstract

Background: Coronary heart disease (CHD) is an important cause of chronic heart failure, and chronic heart failure is also a serious complication in the end stage of coronary heart disease. At present, there is no specific treatment plan. Shenfu injection has advantages in the treatment of heart failure in patients with coronary heart disease, but there is a lack of standard clinical study to verify this. Therefore, the purpose of this randomized controlled trial is to evaluate the efficacy and safety of Shenfu injection combined with furosemide in the treatment of chronic heart failure in patients with coronary heart disease. Methods: This is a prospective randomized controlled trial to study the efficacy and safety of Shenfu injection combined with furosemide in the treatment of coronary heart disease and chronic heart failure. This study will be approved by the clinical research ethics committee of our hospital. The patients will be randomly divided into two groups according to 1:1:(a) Shenfu injection combined with furosemide group and (b) simple furosemide group. Standard treatment for 7 days followed up for 30 days at the same time, pay attention to its efficacy and safety indicators. The total effective rate of cardiac function improvement, left ventricular ejection fraction (LVEF), N-terminal pro-brain natriuretic peptide (NT-pro BNP), 6-minute walk test (6-MWTD), and adverse reactions will be observed. Data will be analyzed using the statistical software package SPSS version 25.0 (Chicago, IL). Discussion: This study will evaluate the efficacy and safety of Shenfu injection combined with furosemide in the treatment of coronary heart disease with chronic heart failure. The results of this experiment will provide a clinical basis for Shenfu injection combined with furosemide in the treatment of coronary heart disease and chronic heart failure. OSF Registration number: doi: 10.17605/OSF.IO/27FPM