Enhanced degradation of poly(ethylene terephthalate) by the addition of lactic acid / glycolic acid: composting degradation, seawater degradation behavior and comparison of degradation mechanism.

The degradability improvement of poly(ethylene terephthalate) (PET), one of the most widely used but non-degradable disposable packaging material, is of great significance. However, the balance between degradability and mechanical properties remains a huge challenge. Herein, simple hydroxy acids, lactic acid (LA) and glycolic acid (GA) as easy hydrolysis sites were introduced into non-degradable PET via melt polycondensation. A series of high molecular weight poly(ethylene terephthalate-co-L­lactide) (PETL) and poly(ethylene terephthalate-co-glycolate) (PETG) copolyesters were synthesized with an excellent tensile strength greater than 50 MPa, much higher than that of most commercially available degradable polymers. The introduction of hydroxy acid endows PET with significantly improved composting and seawater degradation performance. Furtherly, the degradation rate of PETG with hydrophilic GA unit was faster than that of PETL, and the mineralization rate of PETG80 reaches 22.0%. The density of functional theory (DFT) calculation revealed that adding hydroxy acid to the PET molecular chain reduced the energy barrier of the hydrolysis reaction. The molecular polarity index (MPI) analysis furtherly confirmed that the higher affinity between the GA unit and water may be the primary reason for the faster degradation of PETG.

Preoperative Contrast-Enhanced Ultrasound (CEUS) Combined with 125I Seeds Localization in Sentinel Lymph Node Biopsy for Breast Cancer.

OBJECTIVE: To assess the clinical value of contrast-enhanced ultrasound (CEUS) technology in predicting axillary lymph nodes status before surgery, and to explore the feasibility of sentinel lymph nodes (SLNs) localization guided by CEUS combined with 125I implantation for breast cancer. METHODS: From August 2017 to February 2019, 115 patients were included in this prospective study. Before surgery, a microbubble (SonoVue) was injected intradermally next to the areola. The enhancement patterns of SLNs were recorded and 125I seeds were deployed into the enhanced nodes. Then, all patients underwent standard sentinel lymph node biopsy (SLNB) and all 125I seeds were found out guided by a gamma detector in surgery. The localization was considered successful if 125I seeds were implanted in/beside the nodes. RESULTS: SLNs in 103 cases were successfully identified, the success rate was 89.6% (103/115), 118 SLNs were detected in total. 125I seeds were deployed successfully in 99 cases, and all of the 125I-labeled SLNs were then successfully detected by combined method (radionuclides and blue dye). The accuracy of 125I seeds localization was 96.1% (99/103). Based on the enhancement patterns recorded, 34 cases were predicted to have SLNs metastasis (metastasis in 27 cases and no metastasis in 7 cases confirmed by postoperative pathology) and 65 cases were predicted to have no SLNs metastasis (metastasis in 5 cases and no metastasis in 60 cases by pathology). The positive predictive value and negtive predictive value of CEUS in assessing axillary status were 79.4% (27/34) and 92.3% (60/65), respectively. The axillary metastasis rate in CEUS combined with 125I seeds localization was 27.3% (27/99), while the metastasis rate in the combined method of SLNB was 32.3% (32/99). The sensitivity of 125I seeds localization was 84.4% (27/32), the false-negative rate was 15.6% (5/32), and the consistency evaluation was excellent (Kappa value=0.880, P<0.001). CONCLUSION: CEUS combined with 125I seeds implantation can locate SLNs accurately and has excellent consistency with the combined method. The enhancement patterns can provide helpful predicting information of axillary status preoperatively. However, more studies are needed to be carried out to verify our outcomes and explore the feasibility of applying CEUS technology in clinical work.

Prediction of axillary response after neoadjuvant chemotherapy in clinical node positive breast cancer.

BACKGROUND: For clinical lymph node positive (cN+) breast cancer, the false negative rate of sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NAC) is high. Prediction of axillary response after NAC may provide a better way of patient selection. Our study was designed to evaluate factors associated with axillary pathologic complete response (ypN0) after NAC, and to assess the accuracy of the published Olga Kantor predictive model. METHODS: A total of 406 patients with cN+ breast cancer were enrolled in this study. All patients had received full courses of NAC before undergoing axillary lymph node dissection (ALND). Univariate analyses and multivariate analysis were performed to explore independent predictors of ypN0. Then the Olga Kantor model were validated by the data of patients enrolled. The Olga Kantor model is not ideal because the pathological breast tumor response was not available before surgery, the clinical breast tumor response was assessed in our study as a modification. The accuracy of the validation and modification of Olga Kantor model were assessed by the area under receiver operating characteristic (ROC) curve (AUC). RESULTS: Age (P=0.004), molecular subtype (P=0.000), tumor grade (P=0.006), clinical tumor response (P=0.000) and Ki-67 (P=0.009) were correlated with ypN0. Age, molecular subtype and the clinical tumor response were independent predictors of ypN0 (P<0.05). In validation and modification model, the AUC values were 0.795 and 0.789, respectively, there were no significant differences between the two models (P=0.536). For model score ≤3, 4-7 and ≥8 in the modification model, the ypN0 rate were 3.9% (2/51), 22.5% (59/262) and 67.7% (63/93), respectively. CONCLUSIONS: The Olga Kantor predictive model had high accuracy predicting ypN0 after NAC. Our modification model achieved the same predictive efficiency but is more feasible for clinical practice. Patients with higher scores were more likely to achieve ypN0, so SLNB might be a better way than ALND. However, more patient data and multicenter cohort trials are needed to verify the study.

Internal Mammary Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy in Breast Cancer.

PURPOSE: The definition of nodal pathologic complete response (pCR) after a neoadjuvant chemotherapy (NAC) just included the evaluation of axillary lymph node (ALN) without internal mammary lymph node. This study aimed to evaluate the feasibility of internal mammary-sentinel lymph node biopsy (IM-SLNB) in patients with breast cancer who underwent NAC. METHODS: From November 2011 to 2017, 179 patients with primary breast cancer who underwent operation after NAC were included in this study. All patients received radiotracer injection with modified injection technology. IM-SLNB would be performed on patients with internal mammary sentinel lymph node (IMSLN) visualization. RESULTS: Among the 158 patients with cN+ disease, the rate of nodal pCR was 36.1% (57/158). Among the 179 patients, the visualization rate of IMSLN was 31.8% (57/179) and was 12.3% (7/57) and 87.7% (50/57) among those with cN0 and cN+ disease, respectively. Furthermore, the detection rate of IMSLN was 31.3% (56/179). The success rate of IM-SLNB was 98.2% (56/57). The IMSLN metastasis rate was 7.1% (4/56), and all of them were accompanied by ALN metastasis. The number of positive ALNs in patients with IMSLN metastasis was 3, 6, 8, and 9. The pathology nodal stage had been changed from pN1/pN2 to pN3b. The pathology stage had been changed from IIA/IIIA to IIIC. CONCLUSION: Patients with visualization of IMSLN should perform IM-SLNB after NAC, especially for patients with cN+ disease, in order to complete lymph nodal staging. IM-SLNB could further improve the definition of nodal pCR and guide the internal mammary node irradiation.

Internal mammary sentinel lymph node biopsy with modified injection technique: A case report.

RATIONALE: In addition to axillary lymph node (ALN), internal mammary lymph node (IMLN) is also the first-echelon drainage nodes reached by metastasising cancer cells from breast cancer, which can provide important prognostic information. PATIENT CONCERNS: In this paper, we will introduce a case of breast cancer patient whose postoperative pathology result showed that she had internal mammary sentinel lymph node (IMSLN) metastases but no axillary sentinel lymph node (ASLN) metastases. DIAGNOSES: She was diagnosed as pT1cN1bM0 breast cancer based on the positive IMSLN but negative ASLN. INTERVENTIONS: She received axillary-sentinel lymph node biopsy (A-SLNB) and internal mammary-sentinel lymph node biopsy (IM-SLNB) guided by modified injection technique. In the choice of chemotherapy, she received dose-dense AC × 4 times followed P × 4 times for chemotherapy. As to irradiation therapy, she received irradiation therapy include chest wall, superclavicular region, and internal mammary nodes. OUTCOMES: After performing IM-SLNB, the nodal staging of this patient increased (from N0 to N1b). And she received additional chemotherapy and irradiation therapy. LESSONS: With the guidance of modified injection technique, the preoperative visualization rate of IMLN has been improved. IM-SLNB could be a minimally invasive technique for effective evaluation of the status of IMLN to provide information for staging and guide the adjuvant treatment.