Enantioselective recognition of tryptophan isomers with molecularly imprinted overoxidized polypyrrole/poly(p-aminobenzene sulfonic acid) modified electrode.

Poly(p-aminobenzene sulfonic acid) (pABSA) was electrodeposited onto the surface of a glassy carbon electrode (GCE), which was then used for the preconcentration of l-tryptophan (l-Trp) due to the electrostatic and π-π interactions between pABSA and l-Trp. Polypyrrole (PPy) was electrodeposited onto the surface of the l-Trp enriched pABSA, and then the l-Trp templates were removed, resulting in molecularly imprinted PPy/pABSA. To avoid the interference from the oxidation peak of PPy on the following electrochemical chiral recognition of Trp isomers, PPy was overoxidized by cyclic voltammetry (CV). The resultant molecularly imprinted overoxidized PPy (OPPy)/pABSA modified GCE exhibits higher affinity toward l-Trp than d-tryptophan (d-Trp); that is, the oxidation peak current of l-Trp is greatly higher than that of d-Trp at the molecularly imprinted OPPy/pABSA modified GCE.

An An Open-Label, Single Center, Retrospective Study to Evaluate Clinical Outcomes with Surgical Sealant in Bentall Procedures: A Cohort Study.

BACKGROUND: Cardiovascular surgery is associated with substantial risk for postoperative bleeding with increased patient morbidity and mortality. Numerous intraoperative techniques have been utilized to reduce this risk. This study was to assess postoperative bleeding-related parameters following Bentall procedures and to examine the impact of intraoperative surgical sealant application. METHOD: The medical/surgical records of 100 consecutive Bentall procedure cases were examined retrospectively for perioperative surgical sealant use and postoperative bleeding-related outcomes. RESULTS: Of the 100 patient cases, three died during the postoperative period, and 97 were evaluable. Surgical sealant was utilized in 56 patient cases (57.8%). The utilization versus no utilization of surgical sealant was associated with significant reductions in most postoperative bleeding-related parameters, including less drainage (P = .028), resternotomy for hemorrhage (P = .036), transfusion of red blood cells (P = .022 at 48 hours; P = .027 total in-hospital), transfusion of fresh frozen plasma (P = .04 at 48 hours; P = .004 total in-hospital), and a higher percentage of cases not needing blood transfusion (P = .002). The surgical sealant group had longer cardiopulmonary bypass circuit (P = .016) and aortic cross-clamp time (P = .001), with no significant between-group differences in intubation time (P = .636) or intensive care unit duration (P = .294). When excluding urgent cases or Stanford type A aortic dissections, intensive care unit duration significantly was shorter in the surgical sealant group (P = .017). Surgical sealant use was not associated with any adverse events. CONCLUSION: The application of surgical sealant to the anastomosis suture line in Bentall procedures reduces postoperative drainage, bleeding, and transfusion utilization. Further studies are warranted to investigate these benefits in prospective, randomized clinical trials.

Microbial Metabolite Inspired ß-Peptide Polymers Displaying Potent and Selective Antifungal Activity.

Potent and selective antifungal agents are urgently needed due to the quick increase of serious invasive fungal infections and the limited antifungal drugs available. Microbial metabolites have been a rich source of antimicrobial agents and have inspired the authors to design and obtain potent and selective antifungal agents, poly(DL-diaminopropionic acid) (PDAP) from the ring-opening polymerization of ß-amino acid N-thiocarboxyanhydrides, by mimicking ε-poly-lysine. PDAP kills fungal cells by penetrating the fungal cytoplasm, generating reactive oxygen, and inducing fungal apoptosis. The optimal PDAP displays potent antifungal activity with minimum inhibitory concentration as low as 0.4 µg mL-1 against Candida albicans, negligible hemolysis and cytotoxicity, and no susceptibility to antifungal resistance. In addition, PDAP effectively inhibits the formation of fungal biofilms and eradicates the mature biofilms. In vivo studies show that PDAP is safe and effective in treating fungal keratitis, which suggests PDAPs as promising new antifungal agents.

The impact of antifouling layers in fabricating bioactive surfaces.

Bioactive surfaces modified with functional peptides are critical for both fundamental research and practical application of implant materials and tissue repair. However, when bioactive molecules are tethered on biomaterial surfaces, their functions can be compromised due to unwanted fouling (mainly nonspecific protein adsorption and cell adhesion). In recent years, researchers have continuously studied antifouling strategies to obtain low background noise and effectively present the function of bioactive molecules. In this review, we describe several commonly used antifouling strategies and analyzed their advantages and drawbacks. Among these strategies, antifouling molecules are widely used to construct the antifouling layer of various bioactive surfaces. Subsequently, we summarize various structures of antifouling molecules and their surface grafting methods and characteristics. Application of these functionalized surfaces in microarray, biosensors, and implants are also introduced. Finally, we discuss the primary challenges associated with antifouling layers in fabricating bioactive surfaces and provide prospects for the future development of this field. STATEMENT OF SIGNIFICANCE: The nonspecific protein adsorption and cell adhesion will cause unwanted background "noise" on the surface of biological materials and detecting devices and compromise the performance of functional molecules and, therefore, impair the performance of materials and the sensitivity of devices. In addition, the selection of antifouling surfaces with proper chain length and high grafting density is also of great importance and requires further studies. Otherwise, the surface-tethered bioactive molecules may not function in their optimal status or even fail to display their functions. Based on these two critical issues, we summarize antifouling molecules with different structures, variable grafting methods, and diverse applications in biomaterials and biomedical devices reported in literature. Overall, we expect to shed some light on choosing the appropriate antifouling molecules in fabricating bioactive surfaces.