An aminocaproic acid-grafted chitosan derivative with superior antibacterial and hemostatic properties for the prevention of secondary bleeding.

Uncontrolled bleeding is one of the leading causes of human mortality. Existing hemostatic materials or techniques cannot meet the clinical requirements for safe and effective hemostasis. The development of novel hemostatic materials has always been of great interest. Chitosan hydrochloride (CSH), a derivative of chitin, is extensively used on wounds as an antibacterial and hemostatic agent. However, the formation of intra- or intermolecular hydrogen bonds between hydroxyl and amino groups limits its water solubility and dissolution rate and affects its effectiveness in promoting coagulation. Herein, we covalently grafted aminocaproic acid (AA) to the hydroxyl and amino groups of CSH via ester and amide bonds, respectively. The solubility of CSH in water (25 °C) was 11.39 ± 0.98 % (w/v), whereas the AA-grafted CSH (CSH-AA) reached 32.34 ± 1.23 % (w/v). Moreover, the dissolution rate of CSH-AA in water was 6.46 times higher than that of CSH. Subsequent studies proved that CSH-AA is non-toxic, biodegradable, and has superior antibacterial and hemostatic properties to CSH. Additionally, anti-plasmin activity can be exerted by the dissociated AA from the CSH-AA backbone, which can help to lessen secondary bleeding.

Gene mutation profiling in Chinese colorectal cancer patients and its association with clinicopathological characteristics and prognosis.

BACKGROUND: Gene mutations may play an important role in the development, response to treatment and prognosis of colorectal cancer (CRC). This retrospective study aimed to investigate the mutation profiling of Chinese patients with CRC, and its correlation with clinicopathological features and prognosis. METHODS: This study included 1190 Chinese CRC patients who were diagnosed between May 1998 and December 2018 and received clinical genetic testing. The OncoCarta Panel was used to test a total of 238 possible mutations in 19 common oncogenes. RESULTS: Five hundred and eighty-two (48.9%) cases were detected with gene mutations. Of the 582 cases, there were 111 cases (19.7%) with two concurrent mutations, and six cases (1.0%) with three concurrent mutations. KRAS was the most common gene mutation that occurred in all cases (429, 36.1%), followed by PIK3CA (121, 10.2%), NRAS (47, 3.9%), BRAF (35, 2.9%), HRAS (11, 0.9%) and epidermal growth factor receptor (EGFR) (11, 0.9%). AKT1, KIT, FGFR1, FGFR3, FLT3, CDK, ERBB2, ABL1, MET, RET and PDGFRA mutations were also detected in several cases. When it came to prognosis, we found that KRAS/NRAS/PIK3CA/BRAF mutation was not associated with prognosis. But BRAF mutation was associated with poor prognosis in patients who accepted anti-EGFR therapy. CONCLUSIONS: The molecular testing offered the clinical data and mutation profile of Chinese CRC patients. The information of these mutated genes may help to find out the correlation between mutated genes and the development or prognosis of CRC.