Engineered eco-friendly composite membranes with superhydrophobic/hydrophilic dual-layer for DCMD system.

Considerable advancements have been made in the development of hydrophobic membranes for membrane distillation (MD). Nonetheless, the environmentally responsible disposal of these membranes poses a critical concern due to their synthetic composition. Herein, an eco-friendly dual-layered biopolymer-based membrane was fabricated for water desalination. The membrane was electrospun from two bio-polymeric layers. The top hydrophobic layer comprises polycaprolactone (PCL) and the bottom hydrophilic layer from cellulose acetate (CA). Additionally, silica nanoparticles (SiO2 NPs) were electrosprayed onto the top layer of the dual-layered PCL/CA membrane to enhance the hydrophobicity. The desalination performance of the modified PCL-SiO2/CA membrane was compared with the unmodified PCL/CA membrane using a direct contact membrane distillation (DCMD) unit. Results revealed that silica remarkably improves membrane hydrophobicity. The modified PCL-SiO2/CA membrane demonstrated a significant increase in water contact angle of 152.4° compared to 119° for the unmodified membrane. In addition, PCL-SiO2/CA membrane has a smaller average pore size of 0.23 ± 0.16 µm and an exceptional liquid entry pressure of water (LEPw), which is 3.8 times higher than that of PCL/CA membrane. Moreover, PCL-SiO2/CA membrane achieved a durable permeate flux of 15.6 kg/m2.h, while PCL/CA membrane showed unstable permeate flux decreasing approximately from 25 to 12 kg/m2.h over the DCMD test time. Furthermore, the modified PCL-SiO2/CA membrane achieved a high salt rejection value of 99.97% compared to a low value of 86.2% for the PCL/CA membrane after 24 h continuous DCMD operation. In conclusion, the proposed modified PCL-SiO2/CA dual-layer biopolymeric-based membrane has considerable potential to be used as an environmentally friendly membrane for the MD process.

Engineering of Multifunctional Nanocomposite Membranes for Wastewater Treatment: Oil/Water Separation and Dye Degradation.

Multifunctional membrane technology has gained tremendous attention in wastewater treatment, including oil/water separation and photocatalytic activity. In the present study, a multifunctional composite nanofiber membrane is capable of removing dyes and separating oil from wastewater, as well as having antibacterial activity. The composite nanofiber membrane is composed of cellulose acetate (CA) filled with zinc oxide nanoparticles (ZnO NPs) in a polymer matrix and dipped into a solution of titanium dioxide nanoparticles (TiO2 NPs). Membrane characterization was performed using transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), and Fourier transform infrared (FTIR), and water contact angle (WCA) studies were utilized to evaluate the introduced membranes. Results showed that membranes have adequate wettability for the separation process and antibacterial activity, which is beneficial for water disinfection from living organisms. A remarkable result of the membranes' analysis was that methylene blue (MB) dye removal occurred through the photocatalysis process with an efficiency of ~20%. Additionally, it exhibits a high separation efficiency of 45% for removing oil from a mixture of oil-water and water flux of 20.7 L.m-2 h-1 after 1 h. The developed membranes have multifunctional properties and are expected to provide numerous merits for treating complex wastewater.

Hepaticojejunostomy with gastric access loop versus conventional hepaticojejunostomy: a randomized trial.

Roux-en-Y hepaticojejunostomy (RYHJ) with the provision of "gastric access loop" was developed to shorten the distance traveled by the endoscope to reach hepaticojejunostomy (HJ) anastomotic site. The aim of our study was to assess modified RYHJ with gastric access loop (RYHJ-GA) and compare it with conventional RYHJ (RYHJ-C) regarding short- and long-term outcomes and, moreover, to evaluate the feasibility and results of future endoscopic access of the modified bilio-enteric anastomosis. Patients eligible for RYHJ between September 2017 and December 2019 were allocated randomly to receive either RYHJ-C or RYHJ-GA. Fifty-two patients were randomly assigned to RYHJ-C (n = 26) or RYHJ-GA (n = 26). Three cases in RYHJ-C and 4 cases in RYHJ- GA developed HJ anastomotic stricture (HJAS) (P=0.68). 3 cases of RYHJ-GA had successful endoscopic dilation and balloon sweeping of biliary mud (one case) or stones (2 cases). Revisional surgery was needed in 2 cases of RYHJ-C and 1 case in RYHJ-GA (P=0.68). Modified RYHJ with gastric access loop is comparable to the classic hepaticojejunostomy regarding complications. However, gastric access enables easy endoscopic access for the management of future HJAS. This modification should be considered in patients with a high risk of HJAS during long-term follow-up.The trial registration number (TRN) and date of registration:ClinicalTrials.gov (NCT03252379), August 17, 2017.

Therapeutic Role of Subcutaneous Access Loop Created Adjunct to Hepaticojejunostomy for Management of Bile Duct Injury.

BACKGROUND: Roux-en-Y hepaticojejunostomy (RYHJ) is usually required for major bile duct injury (BDI) as a definitive treatment. Hepaticojejunostomy anastomotic stricture (HJAS) is the most feared long-term complication following RYHJ. The ideal management of HJAS remains undefined. The provision of permanent endoscopic access to the bilio-enteric anastomotic site can make endoscopic management of HJAS feasible and attractive option. In this cohort study, we aimed to evaluate short- and long-term outcomes of subcutaneous access loop created adjunct to RYHJ (RYHJ-SA) for management of BDI and its usefulness for endoscopic management of anastomotic stricture if occurred. MATERIALS AND METHODS: This is a prospective study including patients who were diagnosed with iatrogenic BDI and underwent hepaticojejunostomy with subcutaneous access loop between September 2017 and September 2019. RESULTS: This study included a total number of 21 patients whom ages ranged between 18 and 68 years. During follow-up, three cases had HJAS. One patient had the access loop in subcutaneous position. Endoscopy was done but failed to dilate the stricture. The other 2 patients had the access loop in subfascial position. Endoscopy of them failed to enter the access loop due to failure of fluoroscopy to identify the access loop. The three cases underwent redo-hepaticojejunostomy. Parajejunal (parastomal) hernia occurs in 2 patients in whom the access loop was fixed subcutaneous position. CONCLUSION: In conclusion, modified RYHJ with subcutaneous access loop (RYHJ-SA) is associated with reduced quality of life and patient satisfaction. Moreover, its role in endoscopic management of HJAS after biliary reconstruction for major BDI is limited.

Development and Characterization of Cellulose/Iron Acetate Nanofibers for Bone Tissue Engineering Applications.

In tissue engineering, design of biomaterial with a micro/nano structure is an essential step to mimic extracellular matrix (ECM) and to enhance biomineralization as well as cell biocompatibility. Composite polymeric nanofiber with iron particles/ions has an important role in biomineralization and collagen synthesis for bone tissue engineering. Herein, we report development of polymeric cellulose acetate (CA) nanofibers (17 wt.%) and traces of iron acetates salt (0.5 wt.%) within a polymeric solution to form electrospinning nanofibers mats with iron nanoparticles for bone tissue engineering applications. The resulting mats were characterized using field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The resulted morphology indicated that the average diameter of CA decreased after addition of iron from (395 ± 30) to (266 ± 19) nm and had dense fiber distributions that match those of native ECM. Moreover, addition of iron acetate to CA solution resulted in mats that are thermally stable. The initial decomposition temperature was 300 °C of CA/Fe mat > 270 °C of pure CA. Furthermore, a superior apatite formation resulted in a biomineralization test after 3 days of immersion in stimulated environmental condition. In vitro cell culture experiments demonstrated that the CA/Fe mat was biocompatible to human fetal-osteoblast cells (hFOB) with the ability to support the cell attachment and proliferation. These findings suggest that doping traces of iron acetate has a promising role in composite mats designed for bone tissue engineering as simple and economically nanoscale materials. Furthermore, these biomaterials can be used in a potential future application such as drug delivery, cancer treatment, and antibacterial materials.