ABSTRACT
In situ hydrogel has attracted widely attention in hemostasis due to its ability to match irregular defects, but its application is limited by insufficient mechanical strength and long gelation time. Although some specifical in situ chemically cross-linked hydrogels could be fast formed and exhibit high mechanical strength, they unable to absorb blood. Hence their applications were further limited in emergency hemostasis usage. In this study, a robust hydrogel formed by hydration of powders was developed using multiple hydrogen bonds crosslinking. Here, catechol groups modified ε-polylysine (PL-CAT) and polyacrylamide (PAAM) were used to construct the PL-CAT/PAAM hydrogel. This hydrogel could be formed within 7 s to adhere and seal bleeding sites. The catechol groups endowed the hydrogel outstanding adhesive strength, which was 3.5 times of fibrin glue. Besides, the mechanical performance of in-situ PL-CAT/PAAM hydrogel was explored and the results showed that the hydrogel exhibited high compressive strength (0.47 MPa at 85% strain). Most importantly, the blood loss of wound treated with PL-CAT/PAAM hydrogel powders was 1/7 of untreated group, indicating the hydrogel's excellent hemostatic effect. And the cytotoxicity studies indicated that the PL-CAT/PAAM hydrogel had low toxicity. To summarize, this hydrogel could be a potential hemostatic material in emergency situations.
Subject(s)
Acrylic Resins/chemistry , Adhesives/chemical synthesis , Catechols/chemistry , Hemostatics/chemical synthesis , Hydrogels/chemical synthesis , Polylysine/chemistry , Adhesives/pharmacology , Animals , Blood Cells/drug effects , Cell Line , Cells, Cultured , Fibroblasts/drug effects , Hemostatics/pharmacology , Hydrogels/pharmacology , Hydrogen Bonding , Mice , Rats , Tensile StrengthABSTRACT
Studies on mechanisms of antimalarial action of artemisinin and its derivatives had been reviewed after artemisinin as an antimalarial drug was developed in 1972. The research work, which was mainly done by Chinese scholars, was introduced in the paper, and comprised 4 aspects:histopathology on the ultrastructure by electro-microscopy, the metabolism including the pigment clumping of the malarial parasite by biochemical pharmacology, and oxidation and Fe iron’s effect that were discussed in details based on studies from both domestic and international labs.
