Effect of Micellar Morphology on the Temperature-Induced Structural Evolution of ABC Polypeptoid Triblock Terpolymers into Two-Compartment Hydrogel Network.

We investigated the temperature-dependent structural evolution of thermoreversible triblock terpolypeptoid hydrogels, namely poly(N-allyl glycine)-b-poly(N-methyl glycine)-b-poly(N-decyl glycine) (AMD), using small-angle neutron scattering (SANS) with contrast matching in conjunction with X-ray scattering and cryogenic transmission electron microscopy (cryo-TEM) techniques. At room temperature, A100M101D10 triblock terpolypeptoids self-assemble into core-corona-type spherical micelles in aqueous solution. Upon heating above the critical gelation temperature (T gel), SANS analysis revealed the formation of a two-compartment hydrogel network comprising distinct micellar cores composed of dehydrated A blocks and hydrophobic D blocks. At T ≳ T gel, the temperature-dependent dehydration of A block further leads to the gradual rearrangement of both A and D domains, forming well-ordered micellar network at higher temperatures. For AMD polymers with either longer D block or shorter A block, such as A101M111D21 and A43M92D9, elongated nonspherical micelles with a crystalline D core were observed at T < T gel. Although these enlarged crystalline micelles still undergo a sharp sol-to-gel transition upon heating, the higher aggregation number of chains results in the immediate association of the micelles into ordered aggregates at the initial stage, followed by a disruption of the spatial ordering as the temperature further increases. On the other hand, fiber-like structures were also observed for AMD with longer A block, such as A153M127D10, due to the crystallization of A domains. This also influences the assembly pathway of the two-compartment network. Our findings emphasize the critical impact of initial micellar morphology on the structural evolution of AMD hydrogels during the sol-to-gel transition, providing valuable insights for the rational design of thermoresponsive hydrogels with tunable network structures at the nanometer scale.

Absolute quantification methods for Prostate-Specific antigen by Isotope-Dilution mass spectrometry.

Prostate-specific antigen (PSA) is a diagnostic marker for prostate cancer; however, because it is a macromolecular glycoprotein with complex and diverse isoforms, it is difficult to standardize clinical PSA detection results. To overcome this limitation, herein, naturally extracted PSA was characterized as free PSA (fPSA), and the PSA solution was successfully quantified by amino acid analysis coupled with isotope-dilution mass spectrometry (AAA-IDMS) and enzymatic hydrolysis-IDMS; the results could be traced to the International System of Units (SI) through absolutely quantified amino acids and peptides. After protein hydrolysis or digestion condition optimization, amino acids and signature peptides were detected by liquid chromatography-mass spectrometry with the multiple reaction monitoring mode. The mass concentrations of PSA obtained through AAA-IDMS and enzymatic hydrolysis-IDMS were (75.3 ±â€¯1.5) µg/g (k = 2) and (74.7 ±â€¯1.7) µg/g (k = 2), respectively. The PSA weighted average mass concentration was (75.0 ±â€¯1.6) µg/g (k = 2). The consistency assessment between the two methods was successfully validated, ensuring absolute quantitative accuracy. This study lays the foundation for the development of high-order reference materials for the clinical detection of PSA, which can improve the accuracy, reliability, and consistency of clinical PSA test results.

Transcatheter closure of postoperative residual ventricular septal defects using Amplatzer-type perimembranous VSD occluders.

OBJECTIVES: The reoperations of postoperative residual ventricular septal defects (VSDs) are associated with higher risks. Our aim is to assess the efficacy and safety of transcatheter closure of postoperative residual VSDs using perimembranous VSD occluders. METHODS: Twenty-one patients with residual VSDs underwent transcatheter closure in our center from January 2005 to January 2012. The study population consisted of 9 males and 12 females whose ages ranged from 1.9 to 54 years (median age, 8.7 years). Eighteen cases had perimembranous VSD repair previously, 3 cases had tetralogy of Fallot surgical treatment. All patients had signs of left ventricle volume overload (Qp/Qs ≥ 1.5). Two types of perimembranous VSD occluders, symmetric and asymmetric, were used in 14 and 7 cases, respectively. The diameter of residual VSDs ranged from 4-16 mm (mean, 7.8 mm). The waist size of occluders ranged from 6-18 mm. RESULTS: There were 0 deaths and 1 serious adverse event. Intravascular hemolysis occurred in 1 patient (4.8%), lasted for 7 days, and recovered with therapy. A trivial intraprosthetic residual shunt was observed in 2 patients (9.5%) after the procedure and 1 patient (4.8%) at 6 months. Two patients (9.5%) had transient left anterior hemiblock and recovered within the first week after the procedure. At the latest follow-up, no atrioventricular block and new-onset aortic regurgitation occurred. CONCLUSIONS: Transcatheter closure is a feasible and safe management option for patients with postoperative residual VSDs and obviates the need for a second surgery and cardiopulmonary bypass.

One-stage correction of tetralogy of Fallot associated with anomalous origin of the left pulmonary artery from the aorta and aortopulmonary window.

We report a rare case of tetralogy of Fallot associated with anomalous origin of the left pulmonary artery from the aorta and aortopulmonary window. Successful one-stage total correction was performed under cardiopulmonary bypass, including implantation of the left pulmonary artery, repair of aortopulmonary window, and correction of tetralogy of Fallot. The patient experienced an uneventful postoperative course and was asymptomatic at one-year follow-up.