Analysis of the Parotid Glands on an Energy Spectrum CT Iodine Map to Evaluate Irradiation-Induced Acute Xerostomia in Patients With Nasopharyngeal Carcinoma.

Objective: This prospective study aims to evaluate acute irradiation-induced xerostomia during radiotherapy by utilizing the normalized iodine concentration (NIC) derived from energy spectrum computed tomography (CT) iodine maps. Methods: In this prospective study, we evaluated 28 patients diagnosed with nasopharyngeal carcinoma. At 4 distinct stages of radiotherapy (0, 10, 20, and 30 fractions), each patient underwent CT scans to generate iodine maps. The NIC of both the left and right parotid glands was obtained, with the NIC at the 0-fraction stage serving as the baseline measurement. After statistically comparing the NIC obtained in the arterial phase, early venous phase, late venous phase, and delayed phase, we chose the late venous iodine concentration as the NIC and proceeded to analyze the variations in NIC at each radiotherapy interval. Using the series of NIC values, we conducted hypothesis tests to evaluate the extent of change in NIC within the parotid gland across different stages. Furthermore, we identified the specific time point at which the NIC decay exhibited the most statistically significant results. In addition, we evaluated the xerostomia grades of the patients at these 4 stages, following the radiation therapy oncology group (RTOG) xerostomia evaluation standard, to draw comparisons with the changes observed in NIC. Results: The NIC in the late venous phase exhibited the highest level of statistical significance (P < .001). There was a noticeable attenuation in NIC as the RTOG dry mouth grade increased. Particularly, at the 20 fraction, the NIC experienced the most substantial attenuation (P < .001), a significant negative correlation was observed between the NIC of the left, right, and both parotid glands, and the RTOG evaluation grade of acute irradiation-induced xerostomia (P < .001, r = -0.46; P < .001, r = -0.45; P < .001, r = -0.47). The critical NIC values for the left, right, and both parotid glands when acute xerostomia occurred were 0.175, 0.185, and 0.345 mg/ml, respectively, with AUC = 0.73, AUC = 0.75, and AUC = 0.75. Conclusion: The NIC may be used to evaluate changes in parotid gland function during radiotherapy and acute irradiation-induced xerostomia.

By Endowing Polyglutamic Acid/Polylysine Composite Hydrogel with Super Intrinsic Characteristics to Enhance its Wound Repair Potential.

In this study, multifunctional porous composite hydrogels are prepared via composite technology and using poly(glutamic acid) and (polylysine) as precursors, casein as foaming agent, and calcium ions as coagulant. The results show that the as-prepared hydrogels have high porosity and water absorbency, and good mechanical, inherent antibacterial, and bioadhesive properties. The results show such high water absorption, bioadhesion, and porosity of the as-prepared hydrogel can effectively concentrate blood components and seal wounds better. The release of calcium ions in the as-prepared hydrogels can activate coagulation factors. Both factors can play an important role in hemostasis. The excellent hydroscopicity, moisture retention, adhesion, and inherent antibacterial properties of the as-prepared hydrogel can create a moist, sterile, and closed microenvironment for the wound healing. The experimental results of a deep skin defect model have verified its good effect of promoting wound repair. These inherent excellent properties can endow the as-prepared hydrogel with a wide range of application values.

Mixed Modification of the Surface Microstructure and Chemical State of Polyetheretherketone to Improve Its Antimicrobial Activity, Hydrophilicity, Cell Adhesion, and Bone Integration.

Polyetheretherketone (PEEK) is becoming an attractive surgical implant material in the biomedical field. However, its hydrophobicity and biological inertia have seriously hindered its development in the field of biomaterials and application in clinic. In this work, a mixed modification approach of the surface structure and chemical state was proposed to improve hydrophilicity and bioactivity of PEEK and meanwhile endowed it with antimicrobial properties. First, the effect of mixed acids of nitric acid and concentrated sulfuric acid with different volume ratios on the surface morphology of PEEK was quantitatively investigated, so as to obtain an optimal mixed acid of nitric acid and concentrated sulfuric acid with a volume ratio that could create a multilevel porous structure. Based on this, chemical grafting of ethylenediamine was conducted to achieve amination on the surface of the PEEK. The results showed that such double modification of the surface structure and chemical state could endow PEEK not only with antimicrobial activity but also with good hydrophilicity, cell compatibility, and bioactivity, which were beneficial to improve the bone integration ability of PEEK greatly.