Membrane Technique Research Articles

Orthopaedic Advances: Use of Three-Dimensional Metallic Implants for Reconstruction of Critical Bone Defects After Trauma.

Multiple successful strategies exist for the management of critical-sized bone defects. Depending on the location and etiology of an osseous defect, there are nuances that must be considered by the treating surgeon. The induced membrane technique and various modifications of the Ilizarov method (bone transport by distraction osteogenesis) have been the most common methods for biologic reconstruction. Despite the versatility and high union rates reported, they may not be practical for every patient. The rapid expansion of three-dimensional printing of medical devices has led to an increase in their use within orthopaedic surgery, specifically in the definitive treatment of critical bone defects. This article proposes indications and contraindications for implementation of this technology and reviews the available clinical evidence on the use of custom nonresorbable implants for the treatment of traumatic bone loss. Clinical cases are presented to illustrate the scenarios in which this approach is viable.

Effect of CeO2/spherical silica and halloysite nanotubes engineered for targeted drug delivery system to treat breast cancer cells

Cerium oxide nanoparticles (CeO2 NPs) and flavonoid curcumin that has been widely studied for treating diseases involving high reactive oxygen species (ROS). In nanotherapeutics, the particle size, shape, metal oxide dispersity and surface properties of nanocarriers are vital for drug delivery and therapeutic efficiency. Here, cisplatin release behavior on cerium impregnated two different shaped nanocarriers, CeO2/monodispersed spherical silica (Sil) and CeO2/halloysite (Hal) nanotube was studied for potential anti-cancer therapies. For comparison, CeO2 impregnated mesoporous silica MCM-41, SBA-16, Hydroxyapatite and clay were prepared. Subsequently, the nanocomposites were coated with curcumin (25% wt/wt), and cisplatin (Cp) functionalization (5% wt/wt). 5wt%CeO2/Hal/Cp and 5wt%CeO2/Sil/Cp samples were pegylated using lyophilization technique. Physico-chemical analyses revealed the nanosized distribution of CeO2 and functionalization of cisplatin and curcumin. Cp release was studied using automated Franz cell and dialysis membrane techniques. The different structured nanocarriers delivering mechanism was studied by determining the drug kinetic release using four different kinetic models (first order, second order, Higuchi and Korsmeyer-Peppas). In vitro cytotoxicity assay of nano formulations along with free cisplatin and curcumin (Cur) were tested against the breast cancer cell line (MCF-7) for multiple timepoints by MTT assay. The results reveled the efficacy of 5wt%CeO2/Sil/Cp/Cur nanoparticles in delivering cisplatin. On the other hand, 5wt%CeO2/Hal/Cur nanoparticles enhanced the uptake of curcumin in comparison to free curcumin. Overall, pegylated CeO2/Silica nano formulation demonstrated an effective carrier to cisplatin for potential treatment of breast cancer.

EPH119 Systematic Review and Meta-Analysis of Clinical Outcomes of Bone Grafting/Reconstruction Following Segmental Long Bone Defects Treated By Induced Membrane Technique

To systematically evaluate clinical outcomes of bone grafting/reconstruction following segmental long bone defects treated by induced membrane technique (IMT) according to bone defect lengths (≤10, >10-17, >17 cm).

Tuberculous Osteomyelitis of the Fifth Metatarsal Treated Using the Induced Membrane Technique: A Case Report

Tuberculous osteomyelitis of the foot, an uncommon and rare entity, accounts for <0.01% of all tuberculous localizations. Osteomyelitis secondary to tuberculosis is difficult to diagnose and treat, requiring a high suspicion index. We report a case of tuberculous osteomyelitis of the fifth metatarsal bone treated with the induced membrane technique. Here, we report the case of a 40-year-old woman with a history of immunosuppressive treatment presented with a complaint of painful swelling of the left foot. Radiographs showed osteolytic lesions of the fifth metatarsal bone. Initial biopsy suggested tuberculosis. She was surgically treated with the induced membrane technique. Histology confirmed tuberculous osteomyelitis and antituberculous treatment was initiated. Full weight-bearing was allowed after 8 months. At 24 months follow-up, all symptoms were resolved. The radiographs showed an integrated graft. In conclusion, the presence of osteolytic lesions on a plain film should rise high suspicious for a possible infection requiring biopsy, and if confirmed, mandates surgical debridement and reconstruction. The induced membrane technique offers a mean to treat infectious bone defects. Level of Evidence: Level 4.

THE USE OF THE MASQUELET TECHNIQUE IN PAEDIATRIC LIMB RECONSTRUCTION: A CASE SERIES

The Masquelet technique, also known as the ‘induced membrane technique’ has been utilised in adult reconstruction with varied success. However, there is limited literature on its use in children and this study aims to share our experience.Materials & MethodsBetween 2014 and 2022, 7 children underwent bone defect/infection reconstruction using Masquelet technique, four for complications of Congenital Pseudoarthrosis of Tibia (CPT) treatment, two with chronic osteomyelitis and one for Osteogenesis imperfecta with infected nonunion. The length of the defect relative to the length of the bone (index of reconstruction expressed as a percentage), time to union and complications were evaluated with standard radiographs and from electronic medical records.ResultsThe mean age was 11 years and the procedure was done in five tibiae, one femur and a metatarsal. The mean time interval was 7.1 weeks between the first and second stage surgery. The mean index of reconstruction was 25.8% and the mean follow up period was 17 months. Though six patients achieved union with a mean time to union of 6.5 months (range 4.5 to 10), two patients with multiple previous surgeries for CPT decided to have ablation despite union. The interosseous Masquelet technique of cross synostosis between the tibia and fibula is being highlighted.ConclusionsThe Masquelet technique is a reliable method in complex aetiologies and complications that require methodical planning to achieve good results especially in rescue situations of the tibia.

Management of aseptic nonunions and severe bone defects: let us get this thing healed!

Effective nonunion and bone defect management requires consideration of multiple potential contributing factors including biomechanics, biology, metabolic, and patient factors. This article reviews these factors as well as several potential nonunion or bone defect treatments including bone grafts, bone graft substitutes, the induced membrane technique, and distraction osteogenesis. A summary of these concepts and guidelines for an overall approach to management are also provided.

Removal of diclofenac using Fe2O3 nanoparticles stabilised emulsion nanofluid membrane

The present investigation focuses on the removal of Diclofenac (DCF) from aqueous solution by Fe2O3 nanoparticles stabilised emulsion nanofluid membrane (ENM) using n-heptane as solvent and Di-2-ethylhexyl phosphoric acid (D2EHPA) as carrier. Parameters like stripping phase (HNO3) concentration, homogenizer speed and hydrophilic-lipophilic balance were varied to achieve the maximum extraction of DCF. ENMs were characterized by photomicrograph and Turbiscan. Emulsion instability is the main hurdle for the application of emulsion liquid membrane technique on an industrial scale. The study also tries to address this issue. The study is novel in a way as the blending of Span 80 and Span 20 surfactants with Fe2O3 nanoparticles provided stability to emulsion and improved the DCF extraction to 97%. Nanoparticles are interfacially active which ensures better stability to the emulsion and improves the extraction efficiency.

Feasibility evaluation of the induced membrane technique with structural autologous strip bone graft management of phalangeal and metacarpal segmental defects using radiography

PurposeThe purpose of this study was to explore the feasibility and evaluate the clinical outcomes of treatment for phalangeal and metacarpal segmental defects with the induced membrane technique and autologous structural bone grafting.MethodsSixteen patients who sustained phalangeal or metacarpal bone segmental defects were treated by the induced membrane technique and autologous structural bone grafting from June 2020 to June 2021 at our center.ResultsThe average follow-up was 24 weeks (range, 12–40 weeks). Radiography demonstrated union of all bone grafts after an average of 8.6 weeks (range, 8–12 weeks). All incisions at donor and recipient sites demonstrated primary heal without infection complications. The mean visual analog scale score of the donor site was 1.8 (range, 0–5), with a good score in 13 cases and a fair score in 3. The mean total active motion of the fingers was 179.9°.ConclusionsThe feasibility of the induced membrane technique and structural treatment with a cylindrical bone graft for segmental bone defects of the metacarpal or phalanx is demonstrated by follow-up radiography results. The bone graft provided much more stability and structural support in the bone defects, and the bone healing time and bone union rate were ideal.

Evaporation Temperature Alters Physicochemical Characteristics and Volatile Maillard Reaction Products of Non-Centrifugal Cane Sugar (NCS): Comparison of Polyethylene Membrane and Retronasal Aroma Simulator Techniques for the Extraction of Volatile Organic Compounds in NCS

Non-centrifugal cane sugar (NCS) is produced from sugarcane syrup via thermal evaporation. This study aimed to assess the effects of different temperatures during the evaporation process on the physicochemical characteristics and Maillard reaction products (MRPs) of NCS. Evaporation was tested at three final heating temperatures (120, 130, and 140 °C). The moisture content, water activity, L*a*b* color spaces, and ICUMSA (International Commission for Uniform Methods of Sugar Analysis) values of the NCS were determined. Volatile MRPs of NCS were extracted using polyethylene (PE) membrane and retronasal aroma simulator (RAS) techniques, and their components were measured using gas chromatography. A higher evaporation temperature produced NCS with less moisture content and water activity. However, it also led to a darker color, as indicated by lower L* (brightness) and b* (yellow) values in the color spaces. Additionally, higher evaporation temperatures resulted in greater ICUMSA values. Moreover, higher heating increased the amounts of volatile MRPs, such as 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, 2-furanmethanol, 2-methylpyrazine, 2,5-dimethylpyrazine, and 2,6-dimethylpyrazine. Negative correlations were observed between moisture content, water activity, brightness, yellow color, and the total MRPs obtained by PE and RAS extractions. Additionally, positive and significant correlations were confirmed between ICUMSA values and most MRPs. Thus, the evaporation temperature alters the key physicochemical traits and volatile compounds of NCS, affecting its physical stability and flavor quality.

Is a Wiggling-Motion Modified Two-Step Impression Technique as Accurate as Conventional Techniques in Restorative Dentistry?

The purpose of this study was to evaluate dental impression accuracy of one-step and two-step techniques compared to a modified two-step technique. Four impression techniques were compared: (1) a one-step double mix (DM) technique, (2) a cut-out (CO) technique, in which space relief was created using a blade and a laboratory bur, (3) a membrane (ME) technique, in which space relief was created by placing a PVC membrane on top of the putty material during the primary impression, and (4) a wiggling motion (WI) technique, in which PVC membrane was placed and additional wiggling movements were performed during the first 20 s when the primary impression was seated upon the master model (MM). Impressions were poured with type IV stone. Casts were scanned with a laboratory scanner and measurements were made for each cast using three-dimensional analysis software. All groups presented differences compared to MM group, in at least one intra-abutment distance. Groups DM and ME presented the most significant differences, in three and two distances, respectively, whereas CO and WI presented one significant different distance compared to MM. There were no differences between MM and the four techniques for inter-abutment distances. WI yielded similar results with CO technique. Both performed better than the other groups.

Membrane Separation in the Nickel-Contaminated Wastewater Treatment

Nowadays, electroplating plants are factories that use huge amounts of water in the coating process of anti-corrosion layers. They are required to decrease the heavy metal content to very low values before releasing the post-process water into the aquatic environment. They very often decrease their content using coagulation combined with flocculation. However, these processes are often not effective enough, and the concentration of a given metal does not reach a satisfactory low level. The use of membrane techniques to purify this type of wastewater leads to a reduction in the content of heavy metals, including nickel, to zero values. This allows for not only reducing the negative impact on the aquatic environment but also a step toward more conscious management of water resources—namely, the reuse of water in the electroplating process. The following review not only describes the membrane methods used to treat the wastewater considered, e.g., nanofiltration, ultrafiltration, or electrodialysis, but also shows the directions of development of these processes.

The role of Platelet Rich Fibrin (PRF) membrane and conjunctival autograft on TGF-β and collagen type 1 expression in conjunctival wound healing: a literature review

Link of Video Abstract: https://youtu.be/8w4jBvx0pJc Background: Plasma-rich fibrine (PRF) membrane is a new biomembrane useful in ocular surface reconstruction technique. Since its development, PRF membrane has been used successfully in many studies; however, some controversies maintained. This literature study aims to evaluate the role of Platelet Rich Fibrin (PRF) membrane and conjunctival autograft on TGF-β and collagen type 1 expression in conjunctival wound healing. Methods: This literature review compiles and elaborates on previous studies from many authors to support future experimental studies, which will be conducted to compare the effect of PRF membrane and conjunctival autograft on TGF-β and type 1 collagen expression. Results: PRF has many advantages, such as the ability to reduce inflammation, rich in growth factors, and can be a temporary scaffold for fibroblast migration. However, despite its advantages, PRF is not widely used, unlike its counterpart techniques, such as conjunctival autograft. Conjunctival autograft has long been used as an option for ocular surface reconstruction techniques, but it has some limitations. The conjunctival autograft technique cannot be performed in large or bilateral conjunctival damage. Thus, the PRF membrane technique can become a perfect solution for such a case. This literature review will provide more information on how PRF can regulate inflammation and support the conjunctival wound healing process. Conclusion: Some impacts of PRF membrane and conjunctival autograft are still unclear, especially their effect on TGF-β and type 1 collagen expression. This literature review is expected to encourage and support future experimental studies about the impact of PRF and conjunctival autograft on TGF-β and type 1 collagen expression.

Induced Membrane Technique is Effective for the Management of Acute Traumatic Bone Loss in Both Diaphyseal and Metaphyseal Lower Extremity Fractures.

To compare outcomes of Masquelet's induced membrane technique (IMT) in metaphyseal and diaphyseal fractures with acute bone loss. Retrospective cohort study Setting: Four Level 1 Academic Trauma CentersPatients/Participants: Patients acutely treated with IMT for traumatic lower extremity bone loss at four Level 1 trauma centers between 2010-2020. Operative treatment with placement of cement spacer within three weeks of initial injury followed by staged removal and bone grafting to the defect. Fracture union, infection, revision grafting, time to union, and amputation. 120 fractures met inclusion criteria, including 43 diaphyseal fractures (DIM) and 77 metaphyseal fractures (MIM). Demographic characteristics were not significantly different, except for age (DIM 34 years vs MIM 43 years, p< 0.001). Union after treatment with IMT was 89.2% overall. After controlling for age, this was not significantly different between DIM (41/43, 95.3%) and MIM (66/77, 85.7%) (p =0.13), nor was the rate of infection between groups. There was no difference in any secondary outcomes. The overall union rate in the current series of acute lower extremity fractures treated with induced membrane technique was 89%. There was no difference in successful union between patients with diaphyseal bone loss or metaphyseal bone loss treated with IMT. Similarly, there was no difference in patients with tibial or femoral bone loss treated with induced membrane. Defect size after debridement may be more prognostic for secondary operations rather than the limb segment involved or the degree of soft tissue injury. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Tibial Bone Loss: How to Treat without Circular Fixation?

Segmental tibial bone defects (STBD) represent a dilemma for the trauma surgeon; these defects could result from trauma, after debridement for infection, or after tumor resection. We aimed in this review to shed some light on the various reconstruction options without the need to use a circular fixator. Reconstruction options rely on various factors related to the patient, the surgeon, and the nature of the defect (location and size). Various reconstruction techniques include simple bone grafting (autograft or allografts), bone transport [distraction osteogenesis (DO)], induced membrane technique, and vascularized fibular graft. Fixation could be performed using either internal or external fixators; the latter could be a circular or a unilateral frame. Although circular frames (Ilizarov) fixators reported good results, they are still considered cumbersome, need special attention, carry pin tract infection risk, and could not be tolerated by patients. Hence, various other options were introduced, such as bone transport over an intramedullary nail (IMN), rail monolateral external fixator, and tibialisation of the ipsilateral fibula.

Recent developments in ultrafiltration membrane technology for the removal of potentially toxic elements, and enhanced antifouling performance: A review

The presence of high concentrations of heavy metals (potentially toxic elements) in water bodies generates serious environmental issues and health problems that led to a dramatic increase in wastewater treatment costs. Therefore, it is imperative to develop low-cost and efficient technologies for removing these contaminants from wastewater. Membrane processes are advanced techniques for water treatment and ultrafiltration membrane (UF) has some advantages over other membranes as it requires low pressure to perform However, the UF membrane separates contaminants mainly by size exclusion mechanism, resulting in poor decontamination performance for potentially toxic elements and high susceptibility to membrane fouling. The performance of the UF membrane is often affected by organic and biofouling. Hence, researchers are still looking forward to developing new types of UF membranes that will make them more effective for potentially toxic elements removal and overcome the obstacle of fouling. This review aims to provide an overview of the application of UF membranes in potentially toxic element removal through bibliometric analysis and literature review. The incorporation of various organic, inorganic, carbon-based, and composite-based nano-materials into polymers such as zeolites, metal–organic frameworks (MOFs), and graphene oxide (GO) gave encouraging results for the removal of potentially toxic elements from water. Moreover, this review discusses the mechanisms of fouling in UF membranes and how different techniques can be used to control it. In the end, all the materials are evaluated and compared based on their efficiency, toxicity, simplicity in preparation, popularity, and cost efficiency to provide an overall critical view of the work done in this area. Also, the major challenges and limitations of the use of UF membranes are provided which will help to set the direction of future research.

Induced membrane technique combined with a retrograde intramedullary nail for the treatment of infected bone defects of the ankle

In this study, we treated infected ankle bone defects with the induced membrane two-stage technique. The ankle was fused with a retrograde intramedullary nail in the second stage, and the aim of this study was to observe the clinical effect. We retrospectively enrolled patients with infected bone defects of the ankle admitted to our hospital between July 2016 and July 2018. In the first stage, the ankle was temporarily stabilized with a locking plate, and antibiotic bone cement was used to fill the defects after debridement. In the second stage, the plate and cement were removed, the ankle was stabilized with a retrograde nail, and tibiotalar-calcaneal fusion was performed. Then, autologous bone was used to rebuild the defects. The infection control rate, fusion success rate and complications were observed. Fifteen patients were enrolled in the study with an average follow-up of 30 months. Among them, there were 11 males and 4 females. The average bone defect length after debridement was 5.3 cm (2.1–8.7 cm). Finally, 13 patients (86.6%) achieved bone union without recurrence of infection, and 2 patients experienced recurrence after bone grafting. The average ankle-hindfoot function score (AOFAS) increased from 29.75 ± 4.37 to 81.06 ± 4.72 at the last follow-up. The induced membrane technique combined with a retrograde intramedullary nail for the treatment of infected bone defects of the ankle after thorough debridement is an effective treatment method.

Separation of Critical Metals by Membrane Technology under a Circular Economy Framework: A Review of the State-of-the-Art

The demand for critical metals for net-zero technologies, including electric vehicles and wind/solar energy, puts pressure on extraction and recycling processes. As the treatment of solutions is becoming more and more complex and associated with the decreasing concentration of critical metals and the concentration of contaminants increasing, the development of separation techniques is required. Among them, membrane separation has been evaluated for hydrometallurgical processes with similar results to traditional techniques. This work aimed at reviewing the literature on membrane applications to obtain critical metals—lithium (Li), cobalt (Co), and rare earth elements (scandium—Sc, yttrium—Y, lanthanum—La, and neodymium—Nd). The main novelty is that this literature review focuses on the application of membrane techniques in industrial processes, not only water and wastewater treatment. For this, we searched a scientific database for different keywords, and the bibliometric analysis demonstrated a strong linkage between membrane separation and critical metals. The application of membranes to obtain critical metals from primary and secondary sources, acid mine drainage (AMD), industrial wastes, and the recycling of electronic wastes (e-wastes) and brine was revised. Among these traditional technologies, no relation was found with reverse osmosis. The outstanding use of membranes included combinations of solvent extraction techniques, including supported liquid membranes and polymer inclusion membranes.

Hybrid membrane-cryogenic CO2 capture technologies: A mini-review

The use of membranes to capture CO2 is a proven carbon capture technique. Gas separation membranes enhance the mole fraction of CO2 in the feed gas. The membrane separation technique is low-cost because of its compact size, excellent energy efficiency, minimum environmental effect, simplicity of scale-up, fewer moving parts, moderate energy consumption, and ease of handling. Hybrid membrane cryogenic (HMC) and low-temperature membrane cryogenic (LTMC) are hybrid capture systems that combine the advantages of membrane and cryogenic techniques. In the HMC process, the flue gas is first pre-treated by the membrane process for CO2 enrichment and the cryogenic process to capture the CO2. In the LTMC process, low-temperature membrane units increase flue gas CO2 concentration to 50%–75%, and a cryogenic process liquefies the rich CO2 stream. Permeability and selectivity are the crucial parameters of the membrane which determine the CO2 purity and recovery of capture. Most polymeric membranes have a trade-off of CO2/N2 selectivity (αCO2/N2) and CO2 permeability (PCO2). The operating temperatures also impact membrane performance. An anti-trade-off effect was observed upon cooling down by increasing PCO2 and αCO2/N2. With increased PCO2 and αCO2/N2, sub-ambient temperature-based membrane cryogenic CO2 capture techniques will lower power consumption and energy cost for CO2 capture (CC). This review analyses the costs and energy requirements of various HMC and LTMC configurations for CO2 capture. The study also examines the features of the different membranes used and the effect of operating and membrane parameters on the process performance.

Pd(II) and Pt(IV) dispersive or non-dispersive extraction from model and real leach solutions with alkoxyimine-1-propylpyridinium derivatives

The studies present results of Pt(IV) and Pd(II) conventional liquid–liquid extraction and non-dispersive extraction in pseudo-emulsion hollow fiber strip dispersion (PEHFSD) with alkoxyimine-1-propylpyridinium derivatives. Liquid-liquid extraction was used to extract Pd(II) and Pt(IV) both from the model solutions (single and two-component) and from the real solutions, obtained after the leaching PGM from spent automotive catalysts with aqua regia or HCl/H2O2/H2SO4 mixture. The extraction efficiency of Pt(IV) or Pd(II) from one-component solutions with all extractants used (except 4-[1-(2-ethylhexyloxyimine)methyl]-1-propylpyridinium chloride) was high (>90%). However, phase separation took place after 24 h. Also, the coextraction of the H+ ions into the organic phases was observed. It was found that the coextraction of H+ with PGM from one- and two-component model solutions was slight and did not affect the extraction efficiency of PGM. However, for real solutions, the higher the concentration of H+ ions in the feed solution, the stronger the H+ coextraction effect was noted, and resulted in decrease in the extraction efficiency of metal ions from real leach solutions. 3-[1-(decyloxyimine)ethane]-1-propyl-pyridinium chloride (D3EI-PrCl) was found to be asuitable Pd(II) carrier for the liquid membrane technique PEHFSD for the removal of Pd(II) from the Pd(II)/Pt(IV) mixture. The kinetics of the Pd(II) removal depended on the composition of the feed solution; in the presence of Pt(IV), Pd(II) extraction took 2 h, while almost 100% Pd(II) was removed from one-component model solution in 1 h.

BONE DEFECT HEALING USING THE INDUCED MEMBRANE TECHNIQUE AFTER CHRONICALLY INFECTED NONUNION IN A NOVEL RABBIT MODEL

In chronically infected fracture non-unions, treatment requires extensive debridement to remove necrotic and infected bone, often resulting in large defects requiring elaborate and prolonged bone reconstruction. One approach includes the induced membrane technique (IMT), although the differences in outcome between infected and non-infectious aetiologies remain unclear. Here we present a new rabbit humerus model for IMT secondary to infection, and, furthermore, we compare bone healing in rabbits with a chronically infected non-union compared to non-infected equivalents.A 5 mm defect was created in the humerus and filled with a polymethylmethacrylate (PMMA) spacer or left empty (n=6 per group). After 3 weeks, the PMMA spacer was replaced with a beta-tricalcium phosphate (chronOs, Synthes) scaffold, which was placed within the induced membrane and observed for a further 10 weeks. The same protocol was followed for the infected group, except that four week prior to treatment, the wound was inoculated with Staphylococcus aureus (4×106 CFU/animal) and the PMMA spacer was loaded with gentamicin, and systemic therapy was applied for 4 weeks prior to chronOs application.All the animals from the infected group were culture positive during the first revision surgery (mean 3×105 CFU/animal, n= 12), while at the second revision, after antibiotic therapy, all the animals were culture negative. The differences in bone healing between the non-infected and infected groups were evaluated by radiography and histology. The initially infected animals showed impaired bone healing at euthanasia, and some remnants of bacteria in histology. The non-infected animals reached bone bridging in both empty and chronOs conditions.We developed a preclinical in vivo model to investigate how bacterial infection influence bone healing in large defects with the future aim to explore new treatment concepts of infected non-union.