A Ti3C2 MXene-integrated near-infrared-responsive multifunctional porous scaffold for infected bone defect repair.

Infected bone defect repair has long been a major challenge in orthopedic surgery. Apart from bacterial contamination, excessive generation of reactive oxygen species (ROS), and lack of osteogenesis ability also threaten the defect repair process. However, few strategies have been proposed to address these issues simultaneously. Herein, we designed and fabricated a near-infrared (NIR)-responsive, hierarchically porous scaffold to address these limitations in a synergetic manner. In this design, polymethyl methacrylate (PMMA) and polyethyleneimine (PEI) were used to fabricate the porous PMMA/PEI scaffolds via the anti-solvent vapor-induced phase separation (VIPS) process. Then, Ti3C2 MXenes were anchored on the scaffolds through the dopamine-assisted co-deposition process to obtain the PMMA/PEI/polydopamine (PDA)/MXene scaffolds. Under NIR laser irradiation, the scaffolds were able to kill bacteria through the direct contact-killing and synergetic photothermal effect of Ti3C2 MXenes and PDA. Moreover, MXenes and PDA also endowed the scaffolds with excellent ROS-scavenging capacity and satisfying osteogenesis ability. Our experimental results also confirmed that the PMMA/PEI/PDA/MXene scaffolds significantly promoted new bone formation in an infected mandibular defect model. We believe that our study provides new insights into the treatment of infected bone defects.

Hierarchically Porous Implants Orchestrating a Physiological Viscoelastic and Piezoelectric Microenvironment for Bone Regeneration.

The extracellular matrix microenvironment of bone tissue comprises several physiological cues. Thus, artificial bone substitute materials with a single cue are insufficient to meet the demands for bone defect repair. Regeneration of critical-size bone defects remains challenging in orthopedic surgery. Intrinsic viscoelastic and piezoelectric cues from collagen fibers play crucial roles in accelerating bone regeneration, but scaffolds or implants providing integrated cues have seldom been reported. In this study, it is aimed to design and prepare hierarchically porous poly(methylmethacrylate)/polyethyleneimine/poly(vinylidenefluoride) composite implants presenting a similar viscoelastic and piezoelectric microenvironment to bone tissue via anti-solvent vapor-induced phase separation. The viscoelastic and piezoelectric cues of the composite implants for human bone marrow mesenchymal stem cell line stimulate and activate Piezo1 proteins associated with mechanotransduction signaling pathways. Cortical and spongy bone exhibit excellent regeneration and integration in models of critical-size bone defects on the knee joint and femur in vivo. This study demonstrates that implants with integrated physiological cues are promising artificial bone substitute materials for regenerating critical-size bone defects.

Analysis for discharge within 2 days after thoracoscopic anatomic lung cancer surgery.

OBJECTIVES: The risk and beneficial factors of early discharge after thoracoscopic anatomic lung cancer surgery are unknown, and this study aims to investigate predictors and associated 30-day readmission for early discharge. METHODS: We performed a single-center retrospective analysis of 10,834 consecutive patients who underwent thoracoscopic anatomic lung cancer surgery. Two groups were determined based on discharge date: "discharged by postoperative Day 2" and "discharged after postoperative Day 2." Univariable and multivariable analysis were conducted to identify predictors for discharge. Using propensity score matching (PSM) to compare 30-day readmission rate between two cohorts. RESULTS: A total of 1911 patients were discharged by postoperative Day 2. Multivariable analysis identified older age (odds ratio (OR) = 1.014, p < 0.001), male sex (OR = 1.183, p = 0.003), larger tumor size (OR = 1.248, p < 0.001), pleural adhesions (OR = 1.638, p = 0.043), lymph nodes calcification (OR = 1.443, p = 0.009), advanced clinical T stage (vs. T < 2, OR = 1.470, p = 0.010), lobectomy resection (vs. segmentectomy resection, OR = 2.145, p < 0.001) and prolonged operative time (OR = 1.011, p < 0.001) as independent risk factors for discharge after postoperative Day 2. Three adjustable variables including higher FEV1 /FVC (OR = 0.989, p = 0.001), general anesthesia (GA) plus thoracic paravertebral blockade (vs. GA alone, OR = 0.823, p = 0.006) and uni-portal thoracoscopic surgery (vs. multi-portal, OR = 0.349, p < 0.001) were associated with a decreased likelihood of discharge after postoperative Day 2. Before and after a 1:1 PSM, discharged by postoperative Day 2 did not increase the risk of 30-day readmission compared to counterparts. CONCLUSIONS: Carefully selected patients can be safely discharged within 2 days after thoracoscopic anatomic lung cancer surgery. Three modifiable variables may be favorable for promoting discharge by postoperative Day 2.

[Comparison between laparoscopic pyloromyotomy and open pyloromyotomy for infants with congenital hypertrophic pyloric stenosis]

OBJECTIVE: To compare the efficacy of laparoscopic pyloromyotomy with open pyloromyotomy in treatment of congenital hypertrophic pyloric stenosis(CHPS). METHODS: Fifteen patients (age 20%ape;90 days, body weight 2.5 approximate, equals 5.0 kg) with CHPS underwent laparoscopic pyloromyotomy (Group I) and 10 patients (age 26 approximate, equals 90 days, body weight 2.8 approximate, equals 4.5 kg) with CHPS underwent open pyloromyotomy (Group II). Ambulatory 24 hr esophageal pH metry and gastroesophageal mamometry were studied in two groups before and after surgery. RESULTS: All patients presented gastroesophageal reflux (GER) before operation and all reflux parameters were significantly decreased after operation (P<0.01). There was no significant difference between two groups in reflux parameters after surgery. Intragastric pressure (GP) significantly reduced in two groups after operation(3.83+/-1.45)mmHg compared with (2.38+/-0.54)mmHg P<0.01 in Group I,(4.52+/-1.96)mmHg compared with (2.38+/-0.72)mmHg P<0.05 in Guoup II). There was no significant difference in lower esophageal sphincter pressure (LESP), lower esophageal sphincter length (LESL) before and after operation in two groups. The mean operative time for Group I was (32+/-19) mins, which was close to that of Group II after an initial trail. Oral feeding was started 6 h postoperatively in Group I, which was earlier than that in Group II. No technical failures and complications in Group I were encountered. One wound infection and dehiscense was seen in Group II. CLUSION: Laparoscopic pyloromyotomy for infantile hypertrophic pyloric stenosis is safe and feasible, which has lesser complication and similar effect of antireflux as open pyloromyotomy.