Biological Glue Research Articles

Evaluation of risk factors for recurrence by anterior segment optical coherence tomography in pterygium surgery

AbstractPurpose: To study if there is an association between the values obtained by anterior segment optical coherence tomography (AS‐OCT) preoperatively and postoperatively to pterygium surgery using the technique of conjunctival autograft with biological glue and its risk of recurrence.Methods: A prospective one‐year study was carried out in 50 patients with primary pterygium who underwent excision surgery and conjunctival autograft with biological glue. All of them received the same postoperative treatment. They were followed up in the same way by taking preoperative pterygium measurements and postoperative autograft measurements by AS‐OCT and the number of recurrences was recorded. To obtain the measurements, a line was drawn perpendicular to the ocular surface at the level of the scleral spur, and the intersection of this line with the ocular surface was taken as a reference point to measure the length and the thickness of the pterygium at limbus, center and head, and the thickness of the conjunctival autograft at 1 mm (epithelial, stromal and total), 2 mm (total) and 3 mm (total).Results: The postoperatively autograft thickness AS‐OCT measurements were associated with pterygium recurrence after conjunctival autograft with biological glue surgery.Conclusions: There are measurable factors by AS‐OCT that can be correlated with a higher rate of pterygium recurrence after surgery.

Mistletoe Sticks Around: The festive parasite makes an intriguing biological glue.

Mistletoe Sticks Around: The festive parasite makes an intriguing biological glue.

‘Glues’-the basics and practical applicability in oto-rhino-laryngology and head neck surgery: a review

<p class="abstract">Glues or tissue adhesives have attained a foothold in the arena of otorhinolaryngology.and skull base-head neck surgery. At the sites inaccessible to time tested suture application, they facilitate tissue synthesis and local haemostasis, excellent adhesion, elastic consistency, tissue compatibility, and ability to disintegrate and thereby get completely absorbed with time are the properties of an ideal glue tympanoplasty, ossiculoplasty. CSF leak repair are the widely used applications of this suture less modality. Biological and synthetic glues have been developed. The former being the fibrin glues (1940) and the latter, the cyanoacrylates (1960). Moreover in addition to adequate wound closure, a secure fixation of skin grafts, transplants and implants is vital for the success of a surgical intervention. At these crucial sites, tissue adhesives are the preferred option.</p><p class="abstract"> </p><p class="Default"> </p>

Comparison conventional endoscopic myringoplasty with fibrin glue supplemented endoscopic myringoplasty

Introduction: The fibrin tissue glues have been used in many surgeries to reinforce surgical sutures and tissue adhesion. Myringoplasty is the commonly done ear surgery for the perforations of the tympanic membrane, where no suturing is done between remnant membrane and graft. Aim: The aim of the study is to compare the results and effectiveness of this biological fibrin tissue glue in myringoplasty surgeries as a supplementary procedure to conventional endoscopic myringoplasty (CEM) surgeries. Materials and Methods: Seventy patients with chronic suppurative otitis media with tympanic membrane perforation without ossicular and mastoid involvement have been chosen. One group of 35 patients underwent CEM surgeries. In another group of 35 patients, biological fibrin tissue glue, TISSEEL, has been used as supplementary to the CEM surgeries, and the graft uptake rate and hearing improvement were evaluated and compared postoperatively. Results: The graft success rate at 3 months postoperatively was 91.42% in both the groups, that is, 32/35, and these values were not statistically significantly different (P = 1.00). There was a highly statistically significant hearing outcome before and after the surgery in both the CEM and the fibrin tissue glue supplemented endoscopic myringoplasty groups. However, there was no statistically significant change in hearing outcomes between the two groups. Conclusion: In our study, we have got more or less similar results compared with the results of the studies on routine CEM cases. But the high-cost nature of the commercially available fibrin tissue glue makes it difficult to recommend for use in all routine endoscopy myringoplasty cases.

Surgical Training for Bowel Endometriosis: A New Wet-lab Model

To demonstrate a new wet-lab model for training in conservative bowel endometriosis surgery (shaving and discoid resection). Video demonstration. (1) Modeling deep infiltrating endometriosis using cryopreserved porcine rectum. (2) Conservative resection (shaving and discoid resection) using cold scissor and carbon dioxide laser (free beam and fiber). (3) Discoid resection. In this video, we present a new training model for improving the surgical management of bowel endometriosis. After dissection of the serosa and muscular layers, a modified biological glue is injected into the porcine rectum to accurately simulate an infiltrating bowel endometriosis lesion. Once dried, the simulated lesion can be resected using conventional laparoscopic instruments (cold scissors) or using more advanced techniques such as carbon dioxide laser, free beam and fiber (Storz and Lumenis). In case of bowel perforation during resection, this model enables realistic suturing. This new and highly realistic model allows the next generation of endometriosis surgeons to acquire adequate training to make bowel surgery safer and more effective.

MANAGEMENT OF PLASMA-DERIVED MEDICINAL PRODUCTS: SUPPLY AND TRACEABILITY ISSUES

Background:Plasma-derived medicinal products (PDMPs) represent a particular field of pharmaceutical industry. Produced mostly from human blood, PDMPs production follows strict procedures for biological safety and traceability. It comes to albumin, immunoglobulins, coagulating fractions, antiprotease fractions as well as biological glues. Resources and procedures: Our study aimed to define PDMPs management in Morocco, as well as their biological safety procedures, while specifying constraints related to their supply and traceability. Results and discussion: Moroccan market supply by PDMPs is ensured by the National Blood Transfusion Center (NBTC) that shipments Moroccan collected plasma to the French Laboratory of Fractionation and Biotechnology (LFB). The latter produces PDMPs for the Moroccan market under an agreement signed in 1999 and PDMPs prices are fixed by a decree of the Ministry of Health. PDMPs production follows strict procedures for biological safety and traceability from blood donations collection to administration in patients, allowing their routes to be retraced in case of hemovigilance or pharmacovigilance alerts. In Morocco, only two traceability labels are provided on the primary packaging of PDMPs, unlike in some other countries where PDMPs are provided with three sticky labels, all essential for mastering products traceability. PDMPs shortages are due to insufficient amount of plasma sent to LFB, which is aggravated in case of batch recall. Conclusion:PDMPs are indicated to support critical patients, which imply mastering biological safety and traceability from production to delivery, and optimizing their supply in order to ensure their availability by emergency times.

Induction and Phenotyping of Acute Right Heart Failure in a Large Animal Model of Chronic Thromboembolic Pulmonary Hypertension.

The development of acute right heart failure (ARHF) in the context of chronic pulmonary hypertension (PH) is associated with poor short-term outcomes. The morphological and functional phenotyping of the right ventricle is of particular importance in the context of hemodynamic compromise in patients with ARHF. Here, we describe a method to induce ARHF in a previously described large animal model of chronic PH, and to phenotype, dynamically, right ventricular function using the gold standard method (i.e., pressure-volume PV loops) and with a non-invasive clinically available method (i.e., echocardiography). Chronic PH is first induced in pigs by left pulmonary artery ligation and right lower lobe embolism with biological glue once a week for 5 weeks. After 16 weeks, ARHF is induced by successive volume loading using saline followed by iterative pulmonary embolism until the ratio of the systolic pulmonary pressure over systemic pressure reaches 0.9 or until the systolic systemic pressure decreases below 90 mmHg. Hemodynamics are restored with dobutamine infusion (from 2.5 µg/kg/min to 7.5 µg/kg/min). PV-loops and echocardiography are performed during each condition. Each condition requires around 40 minutes for induction, hemodynamic stabilization and data acquisition. Out of 9 animals, 2 died immediately after pulmonary embolism and 7 completed the protocol, which illustrates the learning curve of the model. The model induced a 3-fold increase in mean pulmonary artery pressure. The PV-loop analysis showed that ventriculo-arterial coupling was preserved after volume loading, decreased after acute pulmonary embolism and was restored with dobutamine. Echocardiographic acquisitions allowed to quantify right ventricular parameters of morphology and function with good quality. We identified right ventricular ischemic lesions in the model. The model can be used to compare different treatments or to validate non-invasive parameters of right ventricular morphology and function in the context of ARHF.

The Study of Biological Glue Droplet Impact Behavior of Bioceramic Powders Applied in 3D Printing of Bone Scaffolds

This paper aims to develop a reliable and effective model to investigate the behavior of micron-sized biological glue droplets impacting micron-sized bioceramic powder beds applied to the 3D printing process. It also endeavours to explore the common rules of droplet impact affected by particle size and the wettability of powder, which are supposed to provide process parameters guidance for the application of new materials in 3D printing. Firstly, based on the low impulse impact model, the simplified model was proposed. Then, the observation and simulation experiments of millimeter-scale droplet impacting were carried out under the same conditions to prove the effectiveness of the model. Furthermore, the characterization of a parametric experiment of a 3D printing practice was used to verify the significance and effectiveness of the simulation study method. Lastly, the method was performed to investigate the effect of wettability and particle size of the micron powder on the micron droplet impact. The results showed that the binder powder’s wettability and particle size could directly influence the droplet spreading behavior. The characterization results of samples printed in the simulation-predicted parameter showed that the amount of binder used could be reduced by 38.8~50.1%, while the green strength only lost 17.9~20%. The significance of this simulation method for prediction of 3D printing process parameters was verified.

Postmyocardial infarction ventricular septal defect and ventricular aneurysm repair with a "double-patch frame" technique.

Postmyocardial infarction intraventricular septal rupture is a life-threatening medical condition. Surgical management of postmyocardial infarction ventricular septal defects (PIVSDs) is associated with a 60% mortality and a 40% incidence of residual ventricular septal defects (rVSDs). Our study aimed to describe our modification of the "Double-patch" technique of PIVSD repair without using a biological glue and present its postoperative complications and survival. This was a retrospective observational study. The Bakoulev's Scientific Center of Cardiac Surgery patient admission and discharge database was reviewed from March 2002 to April 2021. The inclusion criterion was PIVSD. Exclusion criteria were conservative treatment, transcatheter closure of PIVSD, PIVSD closure with an interventricular septum patch, and chronic PIVSDs. The study outcomes were echocardiographic parameters of cardiac function, postoperative complications, and mortality. Forty nine patients met the study eligibility criteria. Comparison of echocardiographic data of cardiac function demonstrated reduction in the postoperative period end-diastolic (201.4 ± 59.6 ml vs. 118 [range: 76-207] ml; p < .0005) and end-systolic volumes (106 [51-208] ml vs. 66 [40-147] ml; p < .0005). One (2%) patient developed hemodynamically significant rVSD that required the second run of cardiopulmonary bypass and rVSD closure. Thirteen (26.5%) patients died in the hospital. The overall mortality rate for the study period was 11.4/100 person-years (95% confidence interval [CI]: 6.9-19.0/100 person-years). In these patients, 1-year survival was 68.2% (95% CI: 52.3%-79.8%) and 5-year survival was 63.1% (95% CI: 45.1%-76.7%). The "Double-patch frame" technique restores LV dimensions, has a low rate of hemodynamically significant rVSDs and mortality.

Analysis of Chitosan‐Based Nanosilver Composites for the Repair of Umbilical Cord Wounds in Newborns

The study aim reports a new umbilical cord wound repair material based on modified chitosan‐based nanosilver (CS‐HDH/Ag NPs). The repair of umbilical cord wound has always been the focus of neonatal departments. The study method chitosan, which is famous for its “biological glue,” is used as a modifier to compound silver nanoparticles with strong coordination and adsorption capacity of chitosan. It is worth noting that CS‐HDH/Ag NPs has a significant inhibitory effect on common bacterial infection and reduces the incidence of umbilical cord wound inflammation. The study problem wound bleeding and stump shedding and other factors make the periumbilical cord vulnerable to bacterial infection. For study results, the porous and lamellar structure endows the repair material with breathable properties and excellent antiadhesion, which greatly reduces the number of dressing changes and effectively protects the skin of newborns. CS‐HDH/Ag NPs provides a new model for efficient neonatal health management.

NEUMOCÉFALO INTRAVENTRICULAR ESPONTÁNEO ASOCIADO A AFASIA TRANSITORIA: REPORTE DE CASO Y REVISIÓN DE LA LITERATURA

Introduction: Pneumocephalus or the presence of air in the cranial cavity is common after a craniotomy and in patients with traumatic brain injury; however, its spontaneous appearance is extremely rare. So far, very few cases of spontaneous intraventricular pneumocephalus have been reported. We present the case of a patient who developed spontaneous intraventricular pneumocephalus, which required a craniotomy for surgical correction. Clinical Case: A 59-year-old female patient with a history of left suboccipital craniotomy and resection of the left vestibular Schwannoma who after 2 years presented headache of 3 weeks duration and aphasia of expression. On examination: Mild expressive aphasia, surgical scar with no evidence of cerebrospinal fluid (CSF) leakage. Brain tomography (CT) showed pneumoventricle in the frontal and temporal horns of the left lateral ventricle and deviation from the midline; radionuclide cisternography was negative for CSF fistula and CSF analysis was normal. A left subtemporal craniotomy was performed, finding a bone defect in the petrous portion of the temporal bone above the internal auditory canal associated with a meningocele of the medial base of the skull, which was sealed with bone wax, fat, fascia lata, and biological glue. Conclusion: The first case of spontaneous intraventricular pneumocephalus without identifiable CSF fistula is described, which made this case extremely rare. The treatment performed was a surgical correction of the meningocele through a subtemporal extradural approach, and the patient presented a favorable evolution with the improvement of the aphasia. Keywords: Pneumocephalus, Aphasia, Meningocele, Craniotomy, Temporal Bone (source: MeSH NLM)

Bio-based and bio-inspired adhesives from animals and plants for biomedical applications.

With the “many-headed” slime mold Physarum polycelphalum having been voted the unicellular organism of the year 2021 by the German Society of Protozoology, we are reminded that a large part of nature's huge variety of life forms is easily overlooked – both by the general public and researchers alike. Indeed, whereas several animals such as mussels or spiders have already inspired many scientists to create novel materials with glue-like properties, there is much more to discover in the flora and fauna. Here, we provide an overview of naturally occurring slimy substances with adhesive properties and categorize them in terms of the main chemical motifs that convey their stickiness, i.e., carbohydrate-, protein-, and glycoprotein-based biological glues. Furthermore, we highlight selected recent developments in the area of material design and functionalization that aim at making use of such biological compounds for novel applications in medicine – either by conjugating adhesive motifs found in nature to biological or synthetic macromolecules or by synthetically creating (multi-)functional materials, which combine adhesive properties with additional, problem-specific (and sometimes tunable) features.

Removal of bovine serum albumin and methylene blue using a hybrid membrane of single walled carbon nanotube-banana peel protein: Fabrication and characterization

An environmentally friendly, facile and nondestructive method was developed for the fabrication of nano-bio hybrid membranes. Single-walled carbon nanotubes (SWNTs) were self-assembled via a one-step fabrication procedure using a protein extract from banana peel waste as a biological glue. A large fraction of the protein extract consisted of aliphatic and polar/amphiphilic residues. The hydrophobic functional groups of the protein extract were probably responsible for the binding of the extract to the SWNTs, with this binding involving π - π stacking and hydrophobic interactions, while hydrophilic groups of the protein extract possibly provided an ionic environment for the SWNT-protein hybrids. These hybrids were easily transplanted onto membrane support for use in water treatment. Due to the non-destructive assembly of SWNTs and proteins extracted from the banana peel, the hybrid membranes maintained the electrical conductivity of the SWNTs and hydrophilicity of the protein extract. Water contact angle and porosity values of the hybrid membrane were found to depend on the SWNT and protein contents. Specifically, the porosity and water permeate flux increased with increasing protein content. The SWNT-protein hybrid membrane was successfully used to reject the cationic dye methylene blue and the protein bovine serum albumin, results demonstrating the filtration capability of this membrane. • Self-assembly of SWNTs with the assistance of a protein extract from banana peels. • Applicability of SWNT-protein hybrids for membrane fabrication via a one-step process. • Display of electrical conductivity and hydrophilicity by SWNT-protein hybrid membranes. • Effective removal of contaminants from water by SWNT-protein hybrid membranes.

Application of Biological Glue in Orthopedics and Traumatology

The purpose of the study was to investigate the method of osteosynthesis using glues. Materials and methods. The simplest and most effective method in the treatment of traumatological patients is a plaster fixing bandage of different variations. This is a conservative type of treatment. Also, a very common method in the treatment of orthopedic and traumatological patients is the surgical method. Modern high-tech methods of osteosynthesis require a thorough preoperative examination of the patient, conducting a 3D tomographic examination for intra-articular fractures, clear planning of the course of surgical intervention, electro optical probing techniques during the operation, the availability of tool kits for installing retainers, the ability to choose a retainer intraoperative in the size range. An orthopedic-traumatologist and the entire operating team need appropriate training. All operational fixation methods must provide adequate stability to maintain axis length and rotation. Results and discussion. In the world practice, biological glues are used in such areas as abdominal surgery, neuro- and cardiac surgery, plastic and pediatric surgery, orthopedics and traumatology. Cyanocrylate glues have undergone extensive experimental clinical testing. Positive characteristics of cyanoacrylate glues are the ability to glue living tissues in a humid environment, polymerization rate, autosterility, bactericidal, absence of histotoxicity, hemostatic effect. Another glue in the review is sulfacrylate. It can be used in patients of any age, starting from newborns, regardless of the pathogenesis of the disease. Venaseal glue, used by many authors to treat fistulas of the gastrointestinal tract. Widely used fibrin glues, such as Evicel, are used to achieve hemostasis and sealing in surgery, for example, in vascular operations, kidney resection and neurosurgical interventions, in the surgical treatment of distal hypospadias in children. BioGlue glue is designed to seal surgical sutures, thereby preventing fluids (exudate, lymph, urine, gastric juice) and / or air from leaking through them. It is also used in liver surgery. At the moment, the use of bone cement is the most common auxiliary method for surgical interventions. But its side effects are very clear. Bone cement can cause the patient to die on the operating table or, in the postoperative period, in intensive care. This is due to an immediate or rapid allergic reaction. This situation is dangerous for humans. Biological glues are not so toxic and do not cause such allergic reactions Conclusion. The search for new materials and techniques for consolidating bone fragments is one of the most important problems of modern medical science, namely orthopedics and traumatology. Substances that are included in the biological glue must be bioinert, contain elements of strength (for holding fragments), looseness of the structure (for germination of capillaries between fragments), natural antibiotic (for antibiotic prevention), activators of hematopoiesis processes (for the fastest callus), organic and inorganic substances (for the building material of bone tissue). Therefore, the desire to improve treatment and improve its results, in particular in orthopedics and traumatology, is the key to the development of modern medicine

NOT ALL THE ASPIRATIONS ARE COMING FROM THE OROPHARYNX

TOPIC: Imaging TYPE: Medical Student/Resident Case Reports INTRODUCTION: Aspiration is the entry of oral or gastric materials into the lungs leading to chemical pneumonitis, bacterial infection, or airway obstruction. Frequent conditions that predispose aspiration result from reduced level of consciousness without airway protection, neurologic disorders, or dysphagia from gastrointestinal tract disorders. While the most common route of aspiration is oropharyngeal, tracheoesophageal fistula (TEF) may initially present in the same manner. We present a middle-aged male with repeated aspiration pneumonia and pneumonitis secondary to TEF. CASE PRESENTATION: A 58-year-old male with history of squamous cell lung carcinoma stage IIIa in remission after chemoradiation and recurrent aspiration pneumonia with gastrostomy tube. Presented to the hospital in hypoxic respiratory failure due to sudden onset of dyspnea after attempting tube feeds. Initial evaluation was significant for leukocytosis and normal procalcitonin level. A CT of the chest showed ground glass opacities with consolidation in bilateral upper and lower lobes and tree-in-bud pattern. A bronchoscopy revealed tracheobronchial erythema with multilobar exudate and large tracheal fistula. An Upper GI series identified aspiration coating the trachea and left main bronchus. The patient was diagnosed with chemical pneumonitis and aspiration pneumonia secondary to tracheoesophageal fistula most likely from recurrent infections and radiation. He was transferred to a tertiary care center for esophageal and tracheal stent placement. DISCUSSION: TEF is an abnormal connection between the trachea and the esophagus that is mostly congenital, and in rare occasions can be acquired most commonly through esophageal malignancy, trauma, and chemoradiation. TEF is often associated with abnormal esophageal motility causing recurrent pneumonia and acute lung injury from chemical pneumonitis. Diagnosis of TEF as a result of these conditions can be challenging, but the preferred diagnosis method is direct visualization with esophagoscopy or bronchoscopy. Treatment consists of interventional procedures including airway and/or esophageal stent placement. It is the most common approach to prevent liquid leakage and help with the healing. Biological glue or thermal ablation can also be performed, as well as surgical intervention or conservative management. CONCLUSIONS: The patient presented with respiratory failure secondary to recurrent aspiration pneumonia and chemical pneumonitis who failed therapy with gastrostomy tube placement, due to tracheoesophageal fistula. TEF is a rare complication of chemoradiation that increases morbidity and mortality. It can be treated with airway/esophageal stent placement or more invasive surgical intervention. It is important to expand work up and differential diagnosis in patients with aspiration who continue failing therapy to include endoscopy for direct visualization of anatomical abnormalities. REFERENCE #1: Ke M, Wu X, Zeng J. The treatment strategy for tracheoesophageal fistula. J Thorac Dis. 2015;7(Suppl 4):S389-S397. doi:10.3978/j.issn.2072-1439.2015.12.11 REFERENCE #2: Abugroun A, Ahmed F, Singh N, Nadiri M. Late Onset Chemo/Radiation Induced Tracheoesophageal Fistula in Squamous Cell Cancer of the Lung. World J Oncol. 2017;8(5):171-173. REFERENCE #3: Lo WL, Leu HB, Yang MC, et al. Dysphagia and risk of aspiration pneumonia: A nonrandomized, pair-matched cohort study. J Dent Sci 2019; 14:241. DISCLOSURES: No relevant relationships by Nehal Bhatt, source=Web Response No relevant relationships by Joshuam Ruiz Vega, source=Web Response

The Current Challenges on Spray-Based Cell Delivery to the Skin Wounds

Cell delivery through spray instruments is a promising and effective method in tissue engineering and regenerative medicine. It is used for treating different acute and chronic wounds, including burns with different etiologies, chronic diabetic or venous wounds, postcancer surgery, and hypopigmentation disorders. Cell spray can decrease the needed donor site area compared with conventional autologous skin grafting. Keratinocytes, fibroblasts, melanocytes, and mesenchymal stem cells are promising cell sources for cell spray procedures. Different spray instruments are designed and utilized to deliver the cells to the intended skin area. In an efficient spray instrument, cell viability and wound coverage are two determining parameters influenced by various physical and biological factors such as air pressure, spraying distance, viscosity of suspension, stiffness of the wound surface, and velocity of impact. Besides, to improve cell delivery by spray instruments, some matrices and growth factors can be added to cell suspensions. This review focuses on the different types of cells and spray instruments used in cell delivery procedures. It also discusses physical and biological parameters associated with cell viability and wound coverage in spray instruments. Moreover, the recent advances in codelivery of cells with biological glues and growth factors, as well as clinical translation of cell spraying, have been reviewed. Impact statement Skin wounds are a group of prevalent injuries that can lead to life-threatening complexities. As a focus of interest, stem cell therapy and spray-based cell delivery have effectively decreased associated morbidity and mortality. This review summarizes a broad scope of recent evidence related to spray-based cell therapy, instruments, and approaches adopted to make the process more efficient in treating skin wounds. An overview including utilized cell types, clinical cases, and current challenges is also provided.

Outcomes and prognostic factors of facial nerve repair: a retrospective comparative study of 31 patients and literature review.

To evaluate functional results of facial nerve repair by direct nerve suture or grafting, compare results between a traumatic and a tumoral group and identify prognostic factors. A retrospective monocentric cohort study was studied in a university ENT department. Thirty-one patients who benefited from facial nerve suture or grafting, with at least 12months postoperative follow-up were included. Patients were divided into two groups according to the lesion type: traumatic (accident of the public road or iatrogenic) and tumoral. Preoperative data studied were sex, side, etiology documented by CT and/or MRI, facial palsy duration and grade according to House Brackmann grading system. Intraoperative data included: surgeon, age of patient, surgical technique, graft type, use of biological glue, facial nerve derivation, lesioned site. Postoperative data included: histological diagnosis, radiotherapy history, time to onset of the first signs of reinnervation, follow-up duration, and final facial function. Success rate, including grade III and IV, was 68% in the whole cohort, 79% in the traumatic group and 59% in the tumoral group. Patients presenting with facial palsy evolving less than 6months had better recovery results than those evolving longer than 6months (p = 0.02). No other prognostic factors were identified. The best outcome that can be achieved by suture or grafting of the facial nerve in traumatic or tumoral lesions is a grade III. Preoperative facial palsy duration is a prognostic factor and must be considered when establishing an operative indication.

THE DEVELOPMENT OF BRONCHOPLEURAL FISTULA.

A 66-year-old male with an aspergiloma in the upper left lobe was submitted to a wedge resection in December 2019. Pneumostasis was performed using biological glue and afterward the test of submersion in water showed no significant alveolopleural leak. In the immediate postoperative period, the patient presented an expanded lung parenchyma and moderate alveolopleural leakage that gradually decreased. A month later the patient was readmitted in intensive care unit with an acute respiratory distress after a sudden episode of coughing with abundant and purulent sputum and significant increase in alveolopleural leakage. Intraoperatively it was found that the pulmonary parenchyma covering the segmental bronchi was necrotic.

Current Strategies for Tracheal Replacement: A Review.

Airway cancers have been increasing in recent years. Tracheal resection is commonly performed during surgery and is burdened from post-operative complications severely affecting quality of life. Tracheal resection is usually carried out in primary tracheal tumors or other neoplasms of the neck region. Regenerative medicine for tracheal replacement using bio-prosthesis is under current research. In recent years, attempts were made to replace and transplant human cadaver trachea. An effective vascular supply is fundamental for a successful tracheal transplantation. The use of biological scaffolds derived from decellularized tissues has the advantage of a three-dimensional structure based on the native extracellular matrix promoting the perfusion, vascularization, and differentiation of the seeded cell typologies. By appropriately modulating some experimental parameters, it is possible to change the characteristics of the surface. The obtained membranes could theoretically be affixed to a decellularized tissue, but, in practice, it needs to ensure adhesion to the biological substrate and/or glue adhesion with biocompatible glues. It is also known that many of the biocompatible glues can be toxic or poorly tolerated and induce inflammatory phenomena or rejection. In tissue and organ transplants, decellularized tissues must not produce adverse immunological reactions and lead to rejection phenomena; at the same time, the transplant tissue must retain the mechanical properties of the original tissue. This review describes the attempts so far developed and the current lines of research in the field of tracheal replacement.

Osteo-mucosal engineered construct: In situ adhesion of hard-soft tissues

ObjectivesThe aim of this work was to combine engineered hard and soft tissue, adopting a new method for interfacial adhesion of osteo-mucosal construct. We hypothesized that the chemical procedure involved in this method not only adheres the components, but also improves the cell growth inside them. Methods3D-printed functionally-graded porous hard-tissue scaffolds were characterized, functionalized by aminolysis and tyrosinase, and accommodated by human osteoblast cells. Introducing amino groups through aminolysis and inducing dopaquinones by tyrosinase can take part in the Michael additions to cause the adhesion. Subsequently, fully-differentiated engineered oral mucosa was formed directly on the surface of hard tissue. Constructs were assessed in term of morphology, structure, chemical composition, histology, and cytocompatibility. Interfacial adhesion was compared to a control group prepared by using a biological glue for the attachment of the soft and hard tissues. ResultsThe data confirmed higher proliferation of osteoblast cells via aminolysis and improved osteoblast cells distribution and differentiation by incorporation of tyrosinase in collagen. There was evidence of multilayered, stratified epithelium on the osteo-mucosal model with viable fibroblasts and osteoblasts within the lamina propria and bone tissue layers. Our method of adhesion resulted in cohesive debonding within the engineered soft tissue; while in the control group, adhesive debonding and complete separation of the oral mucosa from the hard tissue was observed. Although the shear strength of the osteo-mucosal model (157.6 kDa ± 25.1) was slightly higher than that of the control group (149.4 kDa ± 23.1), there was no statistically significant difference between them (p > 0.05). However, the advantage of our in situ adhesion approach is the absence of a barrier like glue which can disrupt direct cellular communications between tissues. SignificanceThis study provides a novel method of directly combining tissue-engineered human bone with oral mucosa, which has the potential to improve cell-ingrowth and tissue integration. This engineered tissue construct, after further optimization, can be used clinically as a graft material in various oral surgeries and can also be employed as an in vitro model to investigate many aspects of oral diseases and examine dental materials and oral health care products as a replacement of in vivo models.