Antibacterial 3D-Printed Silver Nanoparticle/Poly Lactic-Co-Glycolic Acid (PLGA) Scaffolds for Bone Tissue Engineering.

Infectious bone defects present a major challenge in the clinical setting currently. In order to address this issue, it is imperative to explore the development of bone tissue engineering scaffolds that are equipped with both antibacterial and bone regenerative capabilities. In this study, we fabricated antibacterial scaffolds using a silver nanoparticle/poly lactic-co-glycolic acid (AgNP/PLGA) material via a direct ink writing (DIW) 3D printing technique. The scaffolds' microstructure, mechanical properties, and biological attributes were rigorously assessed to determine their fitness for repairing bone defects. The surface pores of the AgNPs/PLGA scaffolds were uniform, and the AgNPs were evenly distributed within the scaffolds, as confirmed via scanning electron microscopy (SEM). Tensile testing confirmed that the addition of AgNPs enhanced the mechanical strength of the scaffolds. The release curves of the silver ions confirmed that the AgNPs/PLGA scaffolds released them continuously after an initial burst. The growth of hydroxyapatite (HAP) was characterized via SEM and X-ray diffraction (XRD). The results showed that HAP was deposited on the scaffolds, and also confirmed that the scaffolds had mixed with the AgNPs. All scaffolds containing AgNPs exhibited antibacterial properties against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). A cytotoxicity assay using mouse embryo osteoblast precursor cells (MC3T3-E1) showed that the scaffolds had excellent biocompatibility and could be used for repairing bone tissue. The study shows that the AgNPs/PLGA scaffolds have exceptional mechanical properties and biocompatibility, effectively inhibiting the growth of S. aureus and E. coli. These results demonstrate the potential application of 3D-printed AgNPs/PLGA scaffolds in bone tissue engineering.

Radionuclide-Labeled Microspheres for Radio-Immunotherapy of Hepatocellular Carcinoma.

Brachytherapy, including radioactive seed implantation (RSI) and transarterial radiation therapy embolization (TARE), is an important treatment modality for advanced hepatocellular carcinoma (HCC), but the inability of RSI and TARE to treat tumor metastasis and recurrence limits their benefits for patients in the clinic. Herein, indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors-loaded alginate microspheres (IMs) are developed as radionuclide carriers with immunomodulatory functions to achieve effective radio-immunotherapy. The size and swelling properties of IMs can be facilely tailored by adjusting the calcium source during emulsification. Small/large IMs(SIMs/LIMs) are biocompatible and available for RSI and TARE, respectively, after 177 Lu labeling. Among them, 177 Lu-SIMs completely eliminated subcutaneous HCC in mice after intratumoral RSI. Moreover, in combination with anti-PD-L1, 177 Lu-SIMs not only eradicate primary tumors by RSI but also effectively inhibit the growth of distant tumors, wherein the potent abscopal effect can be ascribed to the immune stimulation of RSI and the modulation of the tumor immune microenvironment (TIME) by IDO1 inhibitors. In parallel, LIMs demonstrate excellent embolization efficiency, resulting in visible necrotic lesions in the central auricular artery of rabbits, which are promising for TARE in future studies. Collectively, a versatile therapeutic agent is provided to synchronously modulate the TIME during brachytherapy for efficient radio-immunotherapy of advanced HCC.

A retrospective evaluation of short-term results from colonic stenting as a bridge to elective surgery versus emergency surgery for malignant colonic obstruction.

The efficacy and safety of self-expanding metallic stent (SEMS) placement as a bridge to elective surgery versus emergency surgery to treat malignant colonic obstruction is debated. This study aimed to evaluate the outcomes of patients with malignant colonic obstruction treated using different procedure. Subjects admitted to the authors' department with colonic obstruction (n = 87) were studied. They underwent colonic stenting as a bridge to elective surgery (SEMS group: n = 14) or emergency surgery (ES group: n = 22).Their demographic characteristics, stoma rate, laparoscopy rate and postoperative complications were analyzed, and the potential risk factors of postoperative complications and the optimal time interval from SEMS implantation to elective surgery were explored. The stoma rate was 15.4% in the SEMS group versus 60.0% in the ES group (P = 0.015), and the postoperative complication rate was 7.7% in the SEMS group versus 40.0% in the ES group (P = 0.042). The proportion of patients undergoing laparoscopy in SEMS group was significantly higher than that in ES group (69.2% vs. 15.0%; P = 0.003).The effect of ASA grade on postoperative complications was statistically significant (OR = 24.565; P = 0.008). The Receiving operating characteristic (ROC) curve could not determine the optimal time interval between SEMS implantation and elective surgery (AUC = 0.466). SEMS implantation has the advantages of lower temporary stoma rate, less postoperative complications and higher laparoscopy rate compared with ES in the treatment of left malignant intestinal obstruction. ASA grade is a risk factor for postoperative complications. However, larger sample size prospective randomized controlled trials (RCT) are still needed to confirm long-term oncological outcomes.