Option For Repair Research Articles

Double-branched stent graft and four-stage deployment in total arch repair: safety and feasibility evaluation in porcine models.

The primary objective of this research was to evaluate the safety and feasibility of an innovative double-branched stent graft system employing four-stage deployment technology for aortic arch repair in porcine models. The double-branched stent graft system consisted of a proximal polyester artificial blood vessel, the main and double-branched stent grafts and a delivery system. We utilized 12 healthy pigs as experimental animals (6 per group). Postimplantation, samples were collected at 90 and 180 days after the operations. Preoperative and postoperative imaging and intraoperative arterial blood gas analyses were performed. After the pigs were euthanized, the implanted product, surrounding tissue and major organs were collected for pathological analysis. The technical success rate of the stent graft implants was 100% (12/12). All animals survived to the experimental end point. Perioperative assessments showed intact stent grafts, and imaging features at the end of the follow-up period revealed neither endoleak nor device migration. No major adverse cardiovascular events were observed during the postoperative follow-up period. Pathological examinations confirmed the satisfactory biocompatibility of the stent graft. This innovative double-branched stent graft system with four-stage deployment technology was affirmed as a safe and feasible option for aortic arch repair in accordance with our preclinical evaluation with porcine models.

GUIDELINES FOR AUTOMOTIVE COMPONENT REPAIR USING ADDITIVE MANUFACTURING IN INDUSTRY 4.0: DESIGN AND PROCESS PERSPECTIVE

The advancement of Industry 4.0 technology requires industries to continuously compete in applying these technologies practically within existing processes. The remanufacturing process as one of the recovery approaches under Circular Economy strategy, is currently thriving on improvement by leveraging Industry 4.0 technology. The application of automated repair through additive manufacturing (AM) is one such opportunity to enhance remanufacturing capabilities with a variety of design options and alternative repair methods. However, AM’s potential as a repair option will be hindered due to challenges in terms of the geometric complexities, process requirements, material compatibilities and process accuracy. Hence, this study focuses on the development of guideline for repair of automotive component through AM process. The development of guideline is crucial to provide newly information and steps involved when conducting the repair using AM technology. The study is mainly focusing on remanufacturable of piston part in a crankshaft component as the case exemplary and Powder Based Fusion (PBF) of metal AM technology is used for verification purposes through experimental works. In overall, this study provides a design guideline involving repair process by using the AM process. The guideline would be useful for the designers, industries and remanufacturers to enhance the implementation of repair and remanufacturing process by adopting AM technology.

The Rejuvenation and Functional Restoration of Aged Adipose Stem Cells by DUXAP10 Knockdown via the Regulation of the miR-214-3p/RASSF5 Axis.

Adipose stem cell (ASC)-based therapies provide an encouraging option for tissue repair and regeneration. However, the function of these cells declines with aging, which limits their clinical transformation. Recent studies have outlined the involvement of long non-coding RNAs in stem cell aging. Here, we reanalyzed our published RNA sequencing (RNA-seq) data profiling differences between ASCs from young and old donors and identified a lncRNA named double homeobox A pseudogene 10 (DUXAP10) as significantly accumulated in aged ASCs. Knocking down DUXAP10 promoted stem cell proliferation and migration and halted cell senescence and the secretion of proinflammatory cytokines. In addition, DUXAP10 was located in the cytoplasm and functioned as a decoy for miR-214-3p. miR-214-3p was downregulated in aged ASCs, and its overexpression rejuvenated aged ASCs and reversed the harm caused by DUXAP10. Furthermore, Ras Association Domain Family Member 5 (RASSF5) was the target of miR-214-3p and was upregulated in aged ASCs. Overexpressing DUXAP10 and inhibiting miR-214-3p both enhanced RASSF5 content in ASCs, while DUXAP10 knockdown promoted the therapeutic ability of aged ASCs for skin wound healing. Overall, this study offers new insights into the mechanism of age-related ASC dysfunction and names DUXAP10 and miR-214-3p as potential targets for energizing aged stem cells.

Perineal hernia repair following tailgut cyst excision: A case report and literature review of optimal management strategies

Perineal hernias, categorised as primary or secondary, pose a clinical challenge necessitating surgical intervention. Herein we present the surgical management of a postoperative perineal hernia of the retrorectal space. A 42-year-old female patient presented to the clinic with symptoms such as perineal discomfort, bulging, and constipation after previous surgical tailgut cyst excision. Diagnosis involved MRI, confirming rectal herniation into the retrorectal space. The surgical approach featured a perineal intervention using a unilateral inferior gluteal flap to reinforce the posterior rectal space, avoiding mesh complications. The patient experienced a successful recovery, highlighting the importance of tailored interventions based on symptoms and complications. Secondary perineal hernias, often postoperative, present diverse challenges influenced by multiple factors such as pelvic surgeries. Surgical repair options include perineal and abdominal approaches, mesh usage, and flap methods, each with variable outcomes. This case study contributes to the evolving understanding of perineal hernias, emphasising the need for multidisciplinary approaches and ongoing research to enhance management strategies in this complex clinical scenario.

Cystic Bleb Management : A Case Report

ABSTRACT Cystic Bleb Is An Abnormal Bleb Morphology Following Trabeculectomy Procedure. This Type Of Bleb Characterized By An Elevated, Thin, And Avascular Bleb Surface. Post-Operative Bleb Evaluation Needed To Be Done Thoroughly To Recognize And Prevent Further Complication Which Can Be Sight Threatening. Several Options Of Management Include Medical Therapy And Surgical Repair. To Report The Management Of Cystic Bleb. The Study Design Is A Case Report Study, Which Was Conducted At Indonesia National Eye Centre, Cicendo Eye Hospital, Bandung, Indonesia. Subject Of The Study Was A-17-Years-Old Female That Presented With Discomfort Sensation In The Right Eye, Which Previously Has Undergone Trabeculectomy Procedure With Antifibrotic Agent Application. Ophthalmological Examination Revealed A Cystic Bleb On The Right Eye. After Medical Therapy Was Given, The Symptoms Persist, Then The Cystic Bleb Was Surgically Repaired. Follow-Up Examination Showed An Improvement Of The Patient’s Condition, Measured By No Further Complaint Of Discomfort Sensation, A Good Bleb Morphology, And A Stable Intraocular Pressure. Cystic Bleb Is One Of The Complication From Trabeculectomy Which Could Progress To Devastating Condition. Surgical Treatment Is Indicated If Symptoms Persist After Medical Management, Or In The Presence Of A Bleb Leakage. Keywords: Antifibrotic, Cystic Bleb, Trabeculectomy

Condition survey and repair proposals for Melin Daron, a derelict Grade II listed mill building in Aberdaron

The roof of Melin Daron, a derelict Grade II listed mill building in Aberdaron, on the Llŷn Peninsula in northwest Wales, had succumbed to leakages over two decades, which left some structural timbers exposed to the elements with some section decayed beyond repair. Mortar joints to the mill building’s exterior walls had almost perished with sections of the internal walls of the corn dryer section partially collapsed, leaving the structure in a precarious situation. In the short term some of the most important structural timber elements had to be repaired, along with repointing masonry and patch repairing the roof with a limited pot of money secured by the client while they sourced a larger funding pot through the National Lottery Heritage Fund (NLHF) to fully repair and preserve this unique building in the long term. This paper seeks to explain the thinking behind the steps taken to make the mill building weathertight while preserving and sympathetically altering historic details that give its unique character. It examines the identification and assessment of defects, before considering various options for conservation and repair.

Double outlet right ventricle - the 50% rule has always been about the conus.

There has been much variability in the definition of double outlet right ventricle (DORV) spanning the last century. Historically, emphasis has been placed on the assignment of the great arteries to the right ventricle as a definition of DORV. In this review, we aim to underscore the importance of conal muscle, rather than rules surrounding assignment of great arteries to ventricles. We will be outlining the variability in patient anatomy that results from variations in conal muscle development in DORV, which may not fit perfectly into predefined constructs. This anatomic variability directly determines physiology and surgical repair options. There is a growing appreciation of the utility of cross-sectional imaging in complex DORV, and the generation of patient-specific 3D models with virtual reality simulations for surgical planning. These models improve the prediction of candidacy for biventricular repair and allow the mapping of complex baffle pathways preoperatively. DORV is not a disease entity in itself, but rather a vast spectrum of disorders associated with maldevelopment of conal muscle and often abnormal expansion of one the great vessels. Patient-specific 3D models will be crucial for improved surgical planning and patient outcomes.

Non-mesh inguinal hernia repair with early resumption of peritoneal dialysis in patients on continuous ambulatory peritoneal dialysis.

Inguinal hernia is a common complication of peritoneal dialysis (PD). Although tension-free mesh repair is a leading option for inguinal hernia repair, concerns over serious mesh-related complications may indicate a role for non-mesh inguinal hernia repair. In addition, there is no consensus on the perioperative dialysis regimen. Early resumption of PD may avoid the additional risks associated with hemodialysis. We report on the outcomes of non-mesh inguinal hernia repair in patients on continuous ambulatory PD (CAPD) and provide a perioperative dialysis protocol that aims to guide early resumption of PD. Between May 2019 and September 2023, thirty CAPD patients with 43 inguinal hernias who underwent non-mesh inguinal hernia repair were retrospectively analyzed. Data on the patient characteristics, perioperative dialysis regimen, perioperative features, complications, and hernia recurrence were collected and assessed. Thirty patients with a total of 43 inguinal hernia repairs were included in this study. The median age was 53years. 23 patients were male and 7 were female. Non-mesh inguinal repair was performed for all patients. PD was resumed at a median of 2days after the surgery. Five patients received interim hemodialysis. There were no postoperative surgical or uremic complications and no recurrence after a median follow-up of 31.5months. Our study demonstrates the effectiveness and safety of non-mesh repair with early resumption of PD in patients on CAPD. Interim HD is unnecessary in selected patients. Choosing the optimal perioperative dialysis regimen is essential to managing inguinal hernias in CAPD patients.

Rework and Repair Options for Steam Turbine Components Subject to Flexible Operation

Abstract The increase in renewable energy penetration on the grid has accelerated the need to transition conventional fossil-based energy sources from their traditional base load operation to more flexible operational regimes. The mode of operation changed dramatically in terms of number of starts, operating hours per annum, and variation in load level. This results in greater thermal transients on operational equipment leading to an increase in Low Cycle Fatigue damage. To ensure the continued integrity of the steam turbine components, it is essential to assess the lifetime status by applying residual lifetime analysis methods. Depending on the amount of lifetime consumption and the extend of potential crack findings, different component repair options are possible. The rework or repair options can be divided into two main groups, namely, cold- and hot-rework. These two options can also be carried out consecutively. All rework or repair options provide the opportunity to improve the application of a component by applying profiling with improved stress fields and even superior materials, in the case of hot rework. The aim of the rework/reconditioning is to ensure that the steam turbine component is suitable for future operation. This ensures that plants are well placed to deliver more flexible operation in the energy industry through carefully tailored refurbishments and reworks.

Midterm Outcomes and Aneurysm Sac Dynamics Following Fenestrated Endovascular Aneurysm Repair after Previous Endovascular Aneurysm Repair

Fenestrated endovascular aneurysm repair (FEVAR) represents a feasible option for aortic repair after endovascular aneurysm repair (EVAR), due to improved peri-operative outcomes compared with open conversion. However, little is known regarding the durability of FEVAR as treatment of failed EVARs. Since aneurysm sac evolution is an important marker for success after aneurysm repair, the aim of the study was to examine mid-term outcomes and aneurysm sac dynamics of FEVAR after prior EVAR. Patients undergoing FEVAR for complex abdominal aortic aneurysms from 2008 to 2021 at two hospitals in The Netherlands were included. Patients were categorised into primary FEVAR and FEVAR after EVAR. Outcomes included five year mortality, one year aneurysm sac dynamics (regression/stable/expansion), sac dynamics over time, and five year aortic related procedures. Analyses were done using Kaplan-Meier methods, multivariable Cox regression analysis, chi-square tests, and linear mixed effect models. In total, 196 patients with FEVAR were identified, of whom 27% (n = 53) had a prior EVAR. Patients with prior EVAR were significantly older (78 ± 6.7 years vs. 73 ± 5.9 years, p < .001). There were no significant differences in mortality. FEVAR after EVAR was associated with higher risk of aortic related procedures within five years (hazard ratio [HR] 2.6; 95% confidence interval [CI] 1.1 - 6.5, p = .037). Sac dynamics were assessed in 154 patients with available imaging. Patients with a prior EVAR showed lower rates of sac regression and higher rates of sac expansion at one year compared with primary FEVAR (sac expansion 48%, n = 21/44, vs. 8%, n = 9/110, p < .001)). Sac dynamics over time showed similar results, sac growth for FEVAR after EVAR, and sac shrinkage for primary FEVAR (p < .001). FEVAR after EVAR showed high rates of sac expansion and needed more secondary procedures than patients with primary FEVAR, although this did not affect mid-term survival. Future studies will have to assess whether FEVAR after EVAR is a valid intervention, and the underlying process that drives aneurysm sac growth following successful FEVAR after EVAR.

Bone formation by human paediatric marrow stromal cells in a functional allogeneic immune system

Allogeneic stem-cell based regenerative medicine is a promising approach for bone defect repair. The use of chondrogenically differentiated human marrow stromal cells (MSCs) has been shown to lead to bone formation by endochondral ossification in immunodeficient pre-clinical models. However, an insight into the interactions between the allogeneic immune system and the human MSC-derived bone grafts has not been fully achieved yet. The choice of a potent source of MSCs isolated from pediatric donors with consistent differentiation and high proliferation abilities, as well as low immunogenicity, could increase the chance of success for bone allografts. In this study, we employed an immunodeficient animal model humanised with allogeneic immune cells to study the immune responses towards chondrogenically differentiated human pediatric MSCs (ch-pMSCs). We show that ch-differentiated pMSCs remained non-immunogenic to allogeneic CD4 and CD8 T cells in an in vitro co-culture model. After subcutaneous implantation in mice, ch-pMSC-derived grafts were able to initiate bone mineralisation in the presence of an allogeneic immune system for 3 weeks without the onset of immune responses. Re-exposing the splenocytes of the humanised animals to pMSCs did not trigger further T cell proliferation, suggesting an absence of secondary immune responses. Moreover, ch-pMSCs generated mature bone after 8 weeks of implantation that persisted for up to 6 more weeks in the presence of an allogeneic immune system. These data collectively show that human allogeneic chondrogenically differentiated pediatric MSCs might be a safe and potent option for bone defect repair in the tissue engineering and regenerative medicine setting.

Study on the Role and Mechanism of Exosomes Derived from Dental Pulp Stem Cells in Promoting Regeneration of Myelin Sheath in Rats with Sciatic Nerve Injury.

The prognosis of peripheral nerve injury (PNI) is usually poor, and currently, there is no effective treatment for PNI. Studies have shown that exosomes derived from mesenchymal stem cells could promote nerve regeneration by optimizing the function of endogenous Schwann cells (SCs), while the mechanism is unclear. Autophagy, a highly conserved intracellular catabolic process responsible for maintaining cellular homeostasis, has been proved to be involved in the regulation of nerve repair after injury. We explored the effect of exosomes derived from dental pulp stem cells (DPSC-Exos) on the regeneration of myelin sheath in rats with sciatic nerve injury (SNI). In vitro and in vivo experiments were performed to clarify whether the effect of DPSC-Exos is associated with autophagy of SCs and to reveal the mechanism at the molecular level. Our results showed that the SCs of SNI rats exhibited the obvious autophagic characteristics, and the increase of P53 expression was an internal factor of autophagy. Our mechanism research indicated that DPSC-Exos could deliver miR-122-5p from DPSCs into SCs and suppressed the rapamycin (RAPA)-induced autophagy in SCs by inhibiting P53 expression. Rescue experiments showed that both the use of GW4869 and overexpression of exogenous P53 in SCs could reverse the inhibitory effect of DPSCs on the autophagy in SCs from co-culture system. In short, our study indicated that DPSC-Exos could promote the regeneration of the myelin sheath through suppressing the autophagy in SCs caused by PNI via miR-122-5p/P53 pathway; this provides researchers with another option for precise repair of PNI.

Minimally invasive transvaginal single-port laparoscopic vesicovaginal fistula repair: a case report and the point of this technique.

The optimal surgical method of vesicovaginal fistula (VVF) remains uncertain. Minimally invasive surgical approaches have become highly popular in line with technological advancements, namely, laparoscopic, robotic, and transvaginal techniques. However, these techniques still require invasiveness. This is the first case report that described a novel "zero-incision" technique for natural orifice transvaginal single-port laparoscopy used to repair a recurrent and high-position VVF. The patient underwent transvaginal single-port laparoscopic repair of a VVF. Methylene blue was used to locate the VVF, and a needle electrode was used to thoroughly remove the scar tissue of the VVF. In addition, this technique for transvaginal single-port laparoscopy provides more working space to expose and repair fistulas conveniently and adequately. One year after surgery, the patient remained asymptomatic and had no fistula recurrence. Minimally invasive transvaginal single-port laparoscopy provides a clear surgical field, is safe and feasible. This novel technique has promising as an additional personalized treatment option for VVF repair.

A critical overview of challenging roles of medicinal plants in improvement of wound healing technology.

Chronic diseases often hinder the natural healing process, making wound infections a prevalent clinical concern. In severe cases, complications can arise, potentially leading to fatal outcomes. While allopathic treatments offer numerous options for wound repair and management, the enduring popularity of herbal medications may be attributed to their perceived minimal side effects. Hence, this review aims to investigate the potential of herbal remedies in efficiently treating wounds, presenting a promising alternative for consideration. A literature search was done including research, reviews, systematic literature review, meta-analysis, and clinical trials considered. Search engines such as Pubmed, Google Scholar, and Scopus were used while retrieving data. Keywords like Wound healing 'Wound healing and herbal combinations', 'Herbal wound dressing', Nanotechnology and Wound dressing were used. This review provides valuable insights into the role of natural products and technology-based formulations in the treatment of wound infections. It evaluates the use of herbal remedies as an effective approach. Various active principles from herbs, categorized as flavonoids, glycosides, saponins, and phenolic compounds, have shown effectiveness in promoting wound closure. A multitude of herbal remedies have demonstrated significant efficacy in wound management, offering an additional avenue for care. The review encompasses a total of 72 studies, involving 127 distinct herbs (excluding any common herbs shared between studies), primarily belonging to the families Asteraceae, Fabaceae, and Apiaceae. In research, rat models were predominantly utilized to assess wound healing activities. Furthermore, advancements in herbal-based formulations using nanotechnology-based wound dressing materials, such as nanofibers, nanoemulsions, nanofiber mats, polymeric fibers, and hydrogel-based microneedles, are underway. These innovations aim to enhance targeted drug delivery and expedite recovery. Several clinical-based experimental studies have already been documented, evaluating the efficacy of various natural products for wound care and management. This signifies a promising direction in the field of wound treatment. In recent years, scientists have increasingly utilized evidence-based medicine and advanced scientific techniques to validate the efficacy of herbal medicines and delve into the underlying mechanisms of their actions. However, there remains a critical need for further research to thoroughly understand how isolated chemicals extracted from herbs contribute to the healing process of intricate wounds, which may have life-threatening consequences. This ongoing research endeavor holds great promise in not only advancing our understanding but also in the development of innovative formulations that expedite the recovery process.

Factors to Consider in Developing Conceptual Scopes of Repair for Common Low-Slope Roofing Assemblies

Forensic engineers are commonly asked to develop conceptual scopes of repair as part of their work. Many factors impact these recommendations, including building codes, construction feasibility, manufacturer assessment, and installation requirements. In addition, the conditions present on and within the existing roof surfaces can limit the repairability of a commercial roof assembly such that removal and replacement of the entire roof section is the appropriate or only feasible repair option. This paper will focus on common limitations to be considered when developing a conceptual scope of repair for common commercial roof systems, including single-ply membranes, built-up roofing, metal panel roofing, spray polyurethane foam roofing, and the application/maintenance of roof coatings. It will also discuss an assessment methodology that can assist in developing a broader understanding of the condition of the roof surfaces.

Bone Anchor Fixation in the Repair of Blunt Traumatic Abdominal Wall Hernias: A Western Trauma Association Multicenter Study.

Blunt traumatic abdominal wall hernias (TAWHs) are rare but require a variety of operative techniques to repair including bone anchor fixation (BAF) when tissue tears off bony structures. This study aimed to provide a descriptive analysis of BAF technique for blunt TAWH repair. Bone anchor fixation and no BAF repairs were compared, hypothesizing increased hernia recurrence with BAF repair. A secondary analysis of the WTA blunt TAWH multicenter study was performed including all patients who underwent repair of their TAWH. Patients with BAF were compared to those with no BAF with bivariate analyses. 176 patients underwent repair of their TAWH with 41 (23.3%) undergoing BAF. 26 (63.4%) patients had tissue fixed to bone, with 7 of those reinforced with mesh. The remaining 15 (36.6%) patients had bridging mesh anchored to bone. The BAF group had a similar age, sex, body mass index, and injury severity score compared to the no BAF group. The time to repair (1 vs 1 days, P = .158), rate of hernia recurrence (9.8% vs 12.7%, P = .786), and surgical site infection (SSI) (12.5% vs 15.6%, P = .823) were all similar between cohorts. This largest series to date found nearly one-quarter of TAWH repairs required BAF. Bone anchor fixation repairs had a similar rate of hernia recurrence and SSI compared to no BAF repairs, suggesting this is a reasonable option for repair of TAWH. However, future prospective studies are needed to compare specific BAF techniques and evaluate long-term outcomes including patient-centered outcomes such as pain and quality of life.

Removal or preservation in place? A review of the conservation management options for asbestos cement sheeting in heritage properties

PurposeInvented in late 1890s, asbestos cement sheeting rose to prominence during the post-Second World War period as a building material for low-cost housing by state housing commissions and low-income families (“fibro homes”). The adverse health effects of asbestos fibres in the building industry and home renovation activities are well documented. Fibro homes of the 1950s and 1960s are increasingly coming under the gaze of heritage studies, which brings to the fore the question of how to deal with the asbestos cement sheeting most are clad with.Design/methodology/approachThis paper provides the first systematic review to assess the literature (126 papers were identified in Google Scholar and scanned for content) on the conservation management of asbestos cement sheeting in heritage properties.FindingsOverall, engagement with the conservation management of asbestos cement sheeting in heritage properties was low, with only two sources dealing with asbestos cement sheeting in any level of detail. The studies note that if asbestos cement sheeting is in good condition, it should be left alone. Numerous conservation and repair options do exist, in particular the application of (coloured) sealants that extend the life of asbestos cement sheets and asbestos cement roofing.Originality/valueThis paper represents the first systematic review to assess conservation management options for asbestos cement sheeting in heritage properties.

Nasal Lining Repair: A Comprehensive Literature Review.

Currently, there are limited reviews in the dermatology literature on how to approach reconstruction of nasal lining in full-thickness nasal defects resulting from Mohs micrographic surgery. Given variable training and experience, dermatologic surgeons may seek additional references to help reconstruct certain advanced defects. We sought to synthesize literature from dermatologic surgery, plastic surgery, and otolaryngology to review repair options and considerations for repair of nasal lining defects. To present a comprehensive literature review of repair options for nasal lining reconstruction and discuss advantages, disadvantages, specific anatomic considerations, and techniques to execute such options. Articles from several different reconstructive specialties including dermatologic/Mohs surgery, otolaryngology, and plastic and reconstructive surgery were reviewed. Instructive images were compiled to illustrate several techniques, with additional medical illustration recreations included to help showcase important reconstructive approaches. A comprehensive descriptive review of nasal lining repair options for the reconstructive surgeon. Advanced tumors can result in full-thickness nasal defects, and this review describes various reconstructive options for reconstruction based on the extent of the defect.

Composite Biosynthetic Graft for Repair of Long-Segment Tracheal Stenosis: A Pilot In Vivo and In Vitro Feasibility Study.

Pediatric patients who undergo surgery for long-segment congenital tracheal stenosis (LSCTS) have suboptimal outcomes and postsurgical complications. To address this, we propose a biosynthetic graft comprising (1) a porcine small intestinal submucosa extracellular matrix (SIS-ECM) patch for tracheal repair, and (2) a resorbable polymeric exostent for biomechanical support. The SIS-ECM patch was evaluated in vivo in an ovine trachea model over an 8 month period. Concurrently, the biosynthetic graft was evaluated in a benchtop lamb trachea model for biomechanical stability. In vivo results show that SIS-ECM performs better than bovine pericardium (control) by preventing granulation tissue/restenosis, restoring tracheal architecture, blood vessels, matrix components, pseudostratified columnar and stratified epithelium, ciliary structures, mucin production, and goblet cells. In vitro tests show that the biosynthetic graft can provide the desired axial and flexural stability, and biomechanical function approaching that of native trachea. These results encourage future studies to evaluate safety and efficacy, including biomechanics and collapse risk, biodegradation, and in vivo response enabling a stable long-term tracheal repair option for pediatric patients with LSCTS and other tracheal defects.

ELECTROWRITING (CELL-LADEN) NATURAL-DERIVED POLYMER FIBRES

Orthopaedic soft tissues, such as tendons, ligaments, and articular cartilage, rely on their unique collagen fiber architectures for proper functionality. When these structures are disrupted in disease or fail to regenerate in engineered tissues, the tissues transform into dysfunctional fibrous tissues. Unfortunately, collagen synthesis in regenerating tissues is often slow, and in some cases, collagen fibers do not regenerate naturally after injury, limiting repair options. One of the research focuses of my team is to develop functional fiber replacements that can promote in vivo repair of musculoskeletal tissues throughout the body. In this presentation, I will discuss our recent advancements in electrowriting 3D printing of natural polymers for creating functional fiber replacements. This manufacturing process utilizes electrical signals to control the flow of polymeric materials through an extrusion nozzle, enabling precise deposition of polymeric fibers with sizes that cannot be achieved using conventional extrusion printing methods. Furthermore, it allows for the formation of fiber organizations that surpass the capabilities of conventional electrospinning processes. During the presentation, I will showcase examples of electrowritten microfiber scaffolds using various naturally-derived polymers, such as gelatin (a denatured form of collagen) and silk fibroin. I will discuss the functional properties of silk-based scaffolds and highlight how they exhibit restored β-sheet and α-helix structures [1]. This restoration results in an elastic response of up to 20% deformation and the ability to withstand cyclic loading without plastic deformation. Additionally, I will present our latest results on the compatibility of this technique with patterning cell-laden fiber structures [2]. This novel biofabrication process allows for the printing of biomimetic microscale architectures with high cell viability, and offers a promising approach to understanding how shear and elongation forces influence cell development of hierarchical (collagen) fibers.Acknowledgements: The author would like to thank the Reprint project (OCENW.XS5.161) and the program “Materials Driven Regeneration” (024.003.013) by the Netherlands Organization for Scientific Research for the financial support.