Soft Tissue Repair Research Articles

Pegylated insulin-like growth factor-1 biotherapeutic delivery promotes rotator cuff regeneration in a rat model.

Tears in the rotator cuff are challenging to repair because of the complex, hypocellular, hypovascular, and movement-active nature of the tendon and its enthesis. Insulin-like Growth Factor-1 (IGF-1) is a promising therapeutic for this repair. However, its unstable nature, short half-life, and ability to disrupt homeostasis has limited its clinical translation. Pegylation has been shown to improve the stability and sustain IGF-1 levels in the systemic circulation without disrupting homeostasis. To provide localized delivery of IGF-1 in the repaired tendons, we encapsulated pegylated IGF-1 mimic and its controls (unpegylated IGF-1 mimic and recombinant human IGF-1) in polycaprolactone-based matrices and evaluated them in a pre-clinical rodent model of rotator cuff repair. Pegylated-IGF-1 mimic delivery reestablished the characteristic tendon-to-bone enthesis structure and improved tendon tensile properties within 8 weeks of repair compared to controls, signifying the importance of pegylation in this complex tissue regeneration. These results demonstrate a simple and scalable biologic delivery technology alternative to tissue-derived grafts for soft tissue repair.

Posterior Glenoid Osteotomy With Capsulolabral Repair Improves Resistance Forces in a Critical Glenoid Bone Loss Model.

Background:There is no widespread consensus on the surgical treatment of posterior shoulder instability with critical posterior glenoid bone loss.Hypothesis:That opening posterior glenoid wedge osteotomy with soft tissue repair would improve the resistance forces of instability when compared with soft tissue repair alone in the setting of 20% critical bone lose.Study Design:Controlled laboratory study.Methods:Native glenoid retroversion was measured on 9 shoulders using computed tomography (CT) scans. The humerus was potted in 90° of forward flexion and 30° of internal rotation relative to the scapula, and a posterior dislocation was performed to create a posterior capsulolabral injury model. The specimens were each taken through a fixed sequence of testing: (1) posteroinferior capsulolabral tear, (2) no glenoid bone loss with posteroinferior capsulolabral repair, (3) 20% posterior glenoid bone loss with posteroinferior capsulolabral repair, and (4) 20% glenoid bone loss with posterior glenoid opening wedge osteotomy and posteroinferior capsulolabral repair. Bone loss was created using a sagittal saw. The resultant peak forces with 1 cm of posterior translation were measured. A 1-way repeated-measures analysis of variance was used to compare mean force values.Results:After the initial dislocation event, all shoulders had a resultant posterior capsulolabral injury. The resulting labral injury was extended from 6- to 9-o’clock in all specimens to homogenize the extent of injury. Repairing the capsulolabral complex in the 20% posterior glenoid bone loss group did not result in a statistically significant increase in resistance force compared with the labral deficient group (34.1 vs 22.2 N; P = .068). When 20% posterior bone loss was created, the posterior glenoid osteotomy with capsulolabral repair was significantly stronger (43.8 N) than the posterior repair alone both with (34.1 N) and without (31.8 N) bone loss (P = .008 and .045, respectively).Conclusion:In the setting of critical posterior glenoid bone loss, an opening wedge posterior glenoid osteotomy with capsulolabral repair improved resistance to posterior humeral translation significantly compared with capsulolabral repair alone.Clinical Relevance:The results of this biomechanical cadaveric study may aid in surgical planning for this complex patient population.

Design of a genetically programmed barnacle-curli inspired living-cell bioadhesive.

In nature, barnacles and bacterial biofilms utilize self-assembly amyloid to achieve strong and robust interface adhesion. However, there is still a lack of sufficient research on the construction of macroscopic adhesives based on amyloid-like nanostructures through reasonable molecular design. Here, we report a genetically programmed self-assembly living-cell bioadhesive inspired by barnacle and curli system. Firstly, the encoding genes of two natural adhesion proteins (CsgA and cp19k) derived from E. coli curli and barnacle cement were fused and expressed as a fundamental building block of the bioadhesive. Utilizing the natural curli system of E. coli, fusion protein can be delivered to cell surface and self-assemble into an amyloid nanofibrous network. Then, the E. coli cells were incorporated into the molecular chain network of xanthan gum (XG) through covalent conjugation to produce a living-cell bioadhesive. The shear adhesive strength of the bioadhesive to the surface of the aluminum sheet reaches 278 ​kPa. Benefiting from living cells encapsulated inside, the bioadhesive can self-regenerate with adequate nutrients. This adhesive has low toxicity to organisms, strong resistance to the liquid environment in vivo, easy to pump, exhibiting potential application prospects in biomedical fields such as intestinal soft tissue repair.

An In Vitro Study of the Effects of Mechanical and Enzymatic Isolation of Stromal Vascular Fraction on Wound Healing.

The adipose-derived stromal vascular fraction (SVF) is considered to be an attractive source of stem cells in cell therapy. Besides stem cells, it also contains functional cells, such as macrophages, precursor cells, somatic stem cells, and pericytes. Collagenase digestion is the most frequently used method to isolate SVF, but it is time-consuming and costly and has some problems, such as infectious agents and immune reactions. In this research, we compared the yield, cell population ratios, and cell viability when isolating SVF by the ultrasonic physics (U-SVF) method and traditional enzymatic method (E-SVF). Then, we isolated exosomes from U-SVF and E-SVF, respectively, and cocultured them with fibroblasts to investigate the potential of applying this cell secretion in wound repair. The results showed that there was no significant difference between the ultrasonic method and enzymatic method in terms of cell viability, cell numbers, or the expression of CD markers of stem cells. However, exosome analysis identified a greater number and smaller size of exosome particles obtained by U-SVF. In terms of cell proliferation efficiency, although the proliferation efficiency of U-SVF was lower than that of E-SVF. Trilineage differentiation experiments revealed that both E-SVF and U-SVF had good differentiation ability, owing to high stem cell content. Finally, E-SVF and U-SVF exosomes were cocultured with fibroblasts. The efficiency of fibroblast migration increased in the SVF exosome treated groups, and the expression of related genes (integrin α5β1) was slightly upregulated; however, the expression of FAK, AKT, ERK, and RhoA was significantly upregulated at 24 hours. From the abovementioned experiments, we found that there was no significant difference in stem cell-related characteristics between SVF isolated by ultrasonic cavitation and SVF isolated by the enzymatic method. In addition, exosomes secreted by SVF may have excellent therapeutic effect on skin injuries, which provides a new viewpoint and therapeutic strategy for soft tissue repair.

Research Progress of Biodegradable Polymers in Repairing Achilles Tendon Injury

Achilles tendon injury has become a common sports injury clinically, and its treatment and rehabilitation are essential, while the regenerative capacity of the Achilles tendon in adult mammals is limited. Therefore, it is necessary to promote the repair and remodelling of the Achilles tendon through efficient interventions. Biodegradable polymer materials are one of the most popular in the treatment and repair of soft tissues, ligaments, muscles, and organs injured by organisms to enhance the function of their wounded sites. Thus, it plays a specific role in “compensation” and is widely used in clinical medicine and rehabilitation. This review summarized the progress of poly (ε-caprolactone), polylactic acid, poly (lactic-co-glycolic acid), poly (trimethylene carbonate) (PTMC), and polydioxanone (PDS) in repairing Achilles tendon injury, indicating that the biodegradable polymers have succeeded in improving and treating Achilles tendon injuries. However, some problems such as lack of good affinity with cells and uncontrollable degradation of the biodegradable polymers should be overcome in repairing Achilles tendon injury. Therefore, the development of modified biodegradable polymers to make them an ideal repair material that meets the requirements is vital in improving Achilles tendon injuries. With the continuous development and close cooperation of life sciences and material sciences, excellent materials for repairing Achilles tendon injuries will undoubtedly be produced. The treatment of Achilles tendon injuries will be more straightforward, which will be a boon for many athletes.

Development of scaffold-free micro-tissues to accelerate soft and hard tissue regeneration via delaying cellular senescence and regulating inflammation

Stem cell therapies are highly attractive due to their potential to repair the injured or diseased tissue and restore function. However, the most commonly used in clinical applications were digested cells (DCs), harvested using trypsin or dispase. And scaffold-based tissue engineering techniques are too complex to achieve clinical transformation. In this work, a novel approach to fabricate scaffold-free micro-tissues (MTs) with high homogeneity and quality on a large scale is reported. The MTs prepared in this way do not require scaffolds and could retain their cell-to-cell interactions and extracellular matrix (ECM). Firstly, temperature-sensitive polymer poly(N-isopropyl acrylamide) (PNIPAM) was adopted as a base coating for the surface of glass slides to facilitate the MTs detachment when the temperature changes from 37 °C to 4 °C. Then polydopamine (PD) was imprinted onto the substrates via microcontact printing (μCP) to fabricate micropatterned substrates. After that, negatively charged heparin was grafted onto the surface of PD patterns to create anti-adhesion networks. Given the rational design and all the components' virtues, we could prepare MTs on a large scale for soft and hard tissue repair with high performance. Compared to the enzyme-treated DCs, the MTs could accelerate soft and hard tissue regeneration via delaying cellular senescence and regulating inflammation.

Biomimetic, highly elastic conductive and hemostatic gelatin/rGO-based nanocomposite cryogel to improve 3D myogenic differentiation and guide in vivo skeletal muscle regeneration

The conductive and hemostatic cryogel capable of mimicking skeletal muscle's conductivity and extracellular matrix component presents huge potential for in situ skeletal muscle tissue engineering. Herein, elastic and conductive nanocomposite cryogels were synthesized using amide bond crosslinked gelatin and poly(tannic acid) reduced graphene oxide (rGO@PTA) via cryopolymerization. The cryogels possessed excellent elasticity, blood-trigged shape memory and 3D macroporous structure. The incorporation of rGO@PTA enhanced the mechanical property and conductivity of the cryogel, and endowed the cryogels with anti-oxidation, and without disturbing the elasticity and macroporous structure. Besides, the rGO@PTA improved the fast degradation of gelatin cryogel to prolong its service life. The cell proliferation and myogenic differentiation of C2C12 myoblasts during 3D culture were significantly improved by the conductive cryogel scaffold. Especially, the cryogel with 4 mg/mL rGO@PTA presented the best cell proliferation and myogenic differentiation, and significantly improved the repair efficiency of volumetric muscle loss. Furthermore, it had better hemostatic efficiency than those of commercial gelatin sponge and gelatin cryogel. This study provides a new strategy to develop highly elastic, hemostatic and conductive scaffolds, which integrates hemostasis and tissue repair to promote skeletal muscle or other electrical signal responsive soft tissue repair via in situ tissue engineering approach.

A pilot multicenter randomized controlled trial comparing Bankart repair and remplissage with the Latarjet procedure in patients with subcritical bone loss (STABLE): study protocol

IntroductionAnterior dislocations, the most common type of shoulder dislocation, are often complicated by subsequent instability. With recurrent dislocations there often is attrition of the labrum and progressive loss of the anterior bony contour of the glenoid. Treatment options for this pathology involve either soft tissue repair or bony augmentation procedure. The optimal management remains unknown and current clinical practice is highly varied.Methods and analysisThe Shoulder instability Trial comparing Arthroscopic stabilization Benefits compared with Latarjet procedure Evaluation (STABLE) is an ongoing multi-centre, pilot randomized controlled trial of 82 patients who have been diagnosed with recurrent anterior shoulder instability and subcritical glenoid bone loss. Patients are randomized to either soft tissue repair (Bankart + Remplissage) or bony augmentation (Latarjet procedure). The primary outcome for this pilot is to assess trial feasibility and secondary outcomes include recurrent instability as well as functional outcomes up to two years post-operatively.ConclusionsThis trial will help to identify the optimal treatment for patients with recurrent shoulder instability with a focus on determining which treatment option results in reduced risk of recurrent dislocation and improved patient outcomes. Findings from this trial will guide clinical practice and improve care for patients with shoulder instability.Trial registrationThis study has been registered on http://www.ClinicalTrials.gov with the following identifier: ClinicalTrials.gov Identifier: NCT03585491, registered 13 July 2018, https://www.clinicaltrials.gov/ct2/show/NCT03585491?term=NCT03585491&draw=2&rank=1.Ethics and disseminationThis study has ethics approval from the McMaster University/Hamilton Health Sciences Research Ethics Board (REB) (approval #4942). Successful completion will significantly impact the global management of patients with recurrent instability. This trial will develop a network of collaboration for future high-quality trials in shoulder instability.

Design of an elastic porous injectable biomaterial for tissue regeneration and volume retention

Soft tissue reconstruction currently relies on two main approaches, one involving the implantation of external biomaterials and the second one exploiting surgical autologous tissue displacement. While both methods have different advantages and disadvantages, successful long-term solutions for soft tissue repair are still limited. Specifically, volume retention over time and local tissue regeneration are the main challenges in the field. In this study the performance of a recently developed elastic porous injectable (EPI) biomaterial based on crosslinked carboxymethylcellulose is analyzed. Nearly quantitative volumetric stability, with over 90% volume retention at 6 months, is observed, and the pore space of the material is effectively colonized with autologous fibrovascular tissue. A comparative analysis with hyaluronic acid and collagen-based clinical reference materials is also performed. Mechanical stability, evidenced by a low-strain elastic storage modulus (G’) approaching 1kPa and a yield strain of several tens of percent, is required for volume retention in-vivo. Macroporosity, along with in-vivo persistence of at least several months, is instead needed for successful host tissue colonization. This study demonstrates the importance of understanding material design criteria and defines the biomaterial requirements for volume retention and tissue colonization in soft tissue regeneration. Statement of significanceWe present the design of an elastic, porous, injectable (EPI) scaffold suspension capable of inducing a precisely defined, stable volume of autologous connective tissue in situ. It combines volume stability and vascularized tissue induction capacity known from bulk scaffolds with the ease of injection in shear yielding materials. By comparative study with a series of clinically established biomaterials including a wound healing matrix and dermal fillers, we establish design rules regarding rheological and compressive mechanical properties as well as degradation characteristics that rationally underpin the volume stability and tissue induction in a high-performance biomaterial. These design rules should allow to streamline the development of new colonizable injectables.

Structural Mechanisms in Soft Fibrous Tissues: A Review

Through years of evolution, biological soft fibrous tissues have developed remarkable functional properties, unique hierarchical architectures, and -most notably, an unparalleled and extremely efficient deformation ability. Whereas the structure-function relationship is well-studied in natural hard materials, soft materials are not getting similar attention, despite their high prevalence in nature. These soft materials are usually constructed as fiber-reinforced composites consisting of diverse structural motifs that result in an overall unique mechanical behavior with large deformations. Biomimetics of their mechanical behavior is currently a significant bioengineering challenge. The unique properties of soft fibrous tissues stem from their structural complexity, which, unfortunately, also hinders our ability to generate adequate synthetic analogs, such that autografts remain the “gold standard” materials for soft-tissue repair and replacement. This review seeks to understand the structural and deformation mechanisms of soft collagenous tissues, with a particular emphasis on tendon and ligaments, the annulus fibrosus (AF) in the intervertebral disc (IVD), skin, and blood vessels. We examined and compared different mechanical and structural motifs in these different tissue types, which are subjected to complex and varied mechanical loads, to isolate the mechanisms of their deformation behavior. Herein, we focused on their composite structure from a perspective of the different building blocks, architecture, crimping patterns, fiber orientation, organization and their structure-function relationship. In the second part of the review, we presented engineered soft composite applications that used these structural motifs to mimic the structural and mechanical behavior of soft fibrous tissues. Moreover, we demonstrated new methodologies and materials that use biomimetic principles as a guide. These novel architectural materials have tailor-designed J-shaped large deformations behavior. Structural motifs in soft composites hold valuable insights that could be exploited to generate the next generation of materials. They actually have a two-fold effect: 1) to get a better understanding of the complex structure-function relationship in a simple material system using reverse biomimetics and 2) to develop new and efficient materials. These materials could revolutionize the future tailor-designed soft composite materials together with various soft-tissue repair and replacement applications that will be mechanically biocompatible with the full range of native tissue behaviors.

Bioglass promotes wound healing by inhibiting endothelial cell pyroptosis through regulation of the connexin 43/reactive oxygen species (ROS) signaling pathway

AbstractBioactive glass (BG) has recently shown great promise in soft tissue repair, especially in wound healing; however, the underlying mechanism remains unclear. Pyroptosis is a novel type of programmed cell death that is involved in various traumatic injury diseases. Here, we hypothesized that BG may promote wound healing through suppression of pyroptosis. To test this scenario, we investigated the possible effect of BG on pyroptosis in wound healing both in vivo and in vitro. This study showed that BG can accelerate wound closure, granulation formation, collagen deposition, and angiogenesis. Moreover, western blot analysis and immunofluorescence staining revealed that BG inhibited the expression of pyroptosis-related proteins in vivo and in vitro. In addition, while BG regulated the expression of connexin43 (Cx43), it inhibited reactive oxygen species (ROS) production. Cx43 activation and inhibition experiments further indicate that BG inhibited pyroptosis in endothelial cells by decreasing Cx43 expression and ROS levels. Taken together, these studies suggest that BG promotes wound healing by inhibiting pyroptosis via Cx43/ROS signaling pathway.

Reducing Complications and Enhancing the Functional Outcome of Total Hip Arthroplasty without Increasing Operation Time by Repairing Posterolateral Soft Tissues.

Total hip arthroplasty (THA) surgeries are increasing annually. Despite continuous improvements in the surgical technique and prosthetic design, there is still no consensus on whether it is beneficial to reconstruct the posterolateral soft tissue. This paper systematically reviews randomized controlled trials (RCTs) addressing the efficacy and safety of posterolateral soft tissue during total hip replacement to provide evidence-based guidance for clinical practice. We searched PubMed, EMBASE, Cochrane Library, CNKI, and Wanfang databases for RCTs. Experimental results show that repair of the posterolateral soft tissue can reduce complications and improve the function of total hip arthroplasty without increasing operative time.

Bioactive glass-based fibrous wound dressings.

Since the discovery of silicate bioactive glass (BG) by Larry Hench in 1969, different classes of BGs have been researched over decades mainly for bone regeneration. More recently, validating the beneficial influence of BGs with tailored compositions on angiogenesis, immunogenicity and bacterial infection, the applicability of BGs has been extended to soft tissue repair and wound healing. Particularly, fibrous wound dressings comprising BG particle reinforced polymer nanofibers and cotton-candy-like BG fibers have been proven to be successful for wound healing applications. Such fibrous dressing materials imitate the physical structure of skin’s extracellular matrix and release biologically active ions e.g. regenerative, pro-angiogenic and antibacterial ions, e.g. borate, copper, zinc, etc., that can provoke cellular activities to regenerate the lost skin tissue and to induce new vessels formation, while keeping an anti-infection environment. In the current review, we discuss different BG fibrous materials meant for wound healing applications and cover the relevant literature in the past decade. The production methods for BG-containing fibers are explained and as fibrous wound dressing materials, their wound healing and bactericidal mechanisms, depending on the ions they release, are discussed. The present gaps in this research area are highlighted and new strategies to address them are suggested.

Initial Experience with a Bioresorbable Polymer Anchor

Category:Ankle; Ankle ArthritisIntroduction/Purpose:Anchors are frequently used in reconstructive orthopedic surgery to achieve fixation of soft tissue to bone. Anchors vary with respect to material composition, configuration, and methods of fixation at the site of attachment. The fixation component of anchoring devices has generally evolved from metal-fabricated implants to various types of bioresorbable anchors. The SonicAnchorTM (Stryker, Kalamazoo, MI USA) polymer implant provides a unique form of anchor fixation using SonicFusionTM technology to achieve interdigitation within cancellous bone while being radiolucent and providing a small footprint.Methods:During a four-year period, 116 patients underwent a reconstructive orthopedic foot and ankle surgical procedure with the use of at least one bioresorbable polymer anchor (SonicAnchor implant). There were 59 males and 57 females, with an average age of 42 years (range: 12-83 years).Results:A total of 233 bioresorbable anchor (SonicAnchor) implants were used in 116 patients. Of the 116 patients, 108 (93.1%) achieved successful clinical healing of their surgery at their most recent follow-up. The average follow-up duration was 309 days (range: 14-1,429 days). Eight (6.9%) patients were lost to follow-up prior to clinical healing. Two (1.7%) patients underwent reoperation. Also, 65 (56%) patients had at least six months of follow-up and 36 (31%) had at least one year of follow-up.Conclusion:This preliminary clinical trial of patients undergoing soft tissue repair or reconstruction with a bioresorbable polymer appears to perform comparably to other commercially available devices. The lack of adverse events, mechanical failures, or infections further supports the safety of this device.

The Outcomes of Soft-Tissue Repair for Posterior Shoulder Instability Surgery.

This study aimed to assess the results after soft-tissue posterior instability surgery and address possible challenges during these operations. The databases of two tertiary hospitals were reviewed to identify patients treated for posterior shoulder instability between 2000 and 2015. Out of 198 treated patients, 19 cases underwent surgery with a mean follow-up of 35 months. Chart review was performed to obtain recurrence rates, revision rates, return to sport, persistent pain, subjective instability, subjective feeling of being better, complications, and range of motion after operative treatment of posterior shoulder instability. These outcomes were compared using the Fisher's exact and Mann-Whitney U tests. After surgery, 6 (32%) patients had a recurrent subluxation, and 11 (58%) cases had persistent pain; moreover, 5 (26%) patients had a persistent feeling of instability, and 10 (53%) cases did not feel improvement after the operation. Furthermore, 10 (53%) patients required a revision, and there were 7 (37%) cases with a complication. Postoperatively, 75% of the patients had a full forward flexion, and 93% of the cases had full internal rotation; however, 64% of them had restrictions in external rotation. There is a high rate of recurrent instability, need for revision, and complications after soft-tissue posterior instability surgery. Postoperative external rotation was impaired in most patients. Patients should be informed about these unsatisfactory results.

Safety Profile of Synthetic Elastic Degradable Matrix for Soft Tissue Reconstruction in Foot & Ankle Surgery.

Augmentation of soft tissue repairs has been helpful in protecting surgically repaired tissues as they heal. FlexBand (Artelon, Marietta, Georgia) is a synthetic, degradable, polycaprolactone-based polyurethane urea (PUUR) matrix that has been investigated and used for soft tissue repair in a variety of settings. The purpose of this study was to evaluate the safety profile of a PUUR matrix in a large cohort of patients undergoing soft tissue repairs about the foot and ankle. A retrospective chart review of consecutive patients who underwent surgery using FlexBand to augment a soft tissue repair was performed to evaluate for major and minor complications related to the PUUR matrix. Results. A total of 105 patients with an average >6 months follow-up were included. The most common procedures were spring ligament repair, Achilles tendon repair, and Brostrom. There were 12 complications. Four major complications occurred with only 1 requiring PUUR matrix removal. Patients with wound complications had a higher body mass index (BMI) and rate of smoking. Complication rates involving PUUR matrix in soft tissue foot and ankle reconstruction procedures are low and comparable with historical complication rates. The PUUR matrix is safe for use in a variety of soft tissue procedures about the foot and ankle.Level of Evidence: Level 4, Retrospective case-series.

N-halamine modified ceria nanoparticles: Antibacterial response and accelerated wound healing application via a 3D printed scaffold

Antibacterial hydrogels are attracting extensive attention in soft tissue repair and regeneration. Herein, a novel three-dimensional (3D) printed dressing with prominent antibacterial activity and biocompatibility was fabricated based on gelatin methacryloyl (GelMA) via a photocrosslinking technique. As the main antibacterial components, CeO2/N-halamine hybrid nanoparticles (NPs) were added to the matrix of carboxymethylcellulose sodium (CMC)/xanthan gum. The 3D printed structure shows excellent shape fidelity and mechanical performance, which considerably enhances the swelling efficiency and blood-clotting ability of the dressings. Furthermore, the introduction of CeO2/N-halamine NPs endow the dressings with efficient antibacterial effect, and 99.6% Staphylococcus aureus and 99.8% Escherichia coli O157:H7 were inactivated when the contact time is up to 30 min. Notably, the fabricated dressings showed outstanding biocompatibility. In vivo experiments indicated that they efficiently accelerated wound closure by promoting the regeneration of dermis and epidermis tissues. This novel 3D printed antibacterial hydrogel might find applications as multifunctional dressings for wound treatments.

The Beirut Port Explosion Injuries and Lessons Learned: Results of the Beirut Blast Assessment for Surgical Services (BASS) Multicenter Study.

This multicenter study aims to describe the injury patterns, emergency management and outcomes of the blast victims, recognize the gaps in hospital disaster preparedness, and identify lessons to be learned. On August 4th, 2020, the city of Beirut, Lebanon suffered the largest urban explosion since Hiroshima and Nagasaki, resulting in hundreds of deaths and thousands of injuries. All injured patients admitted to four of the largest Beirut hospitals within 72 hours of the blast, including those who died on arrival or in the emergency department (ED), were included. Medical records were systematically reviewed for: patient demographics and comorbidities; injury severity and characteristics; prehospital, ED, operative, and inpatient interventions; and outcomes at hospital discharge. Lessons learned are also shared. An estimated total of 1818 patients were included, of which 30 died on arrival or in the ED and 315 were admitted to the hospital. Among admitted patients, the mean age was 44.7 years (range: 1 week-93 years), 44.4% were female, and the median injury severity score (ISS) was 10 (5, 17). ISS was inversely related to the distance from the blast epicenter (r = --0.18, P = 0.035). Most injuries involved the upper extremities (53.7%), face (42.2%), and head (40.3%). Mildly injured (ISS <9) patients overwhelmed the ED in the first 2 hours; from hour 2 to hour 8 post-injury, the number of moderately, severely, and profoundly injured patients increased by 127%, 25% and 17%, respectively. A total of 475 operative procedures were performed in 239 patients, most commonly soft tissue debridement or repair (119 patients, 49.8%), limb fracture fixation (107, 44.8%), and tendon repair (56, 23.4%). A total of 11 patients (3.5%) died during the hospitalization, 56 (17.8%) developed at least 1 complication, and 51 (16.2%) were discharged with documented long-term disability. Main lessons learned included: the importance of having key hospital functions (eg, laboratory, operating room) underground; the nonadaptability of electronic medical records to disasters; the ED overwhelming with mild injuries, delay in arrival of the severely injured; and the need for realistic disaster drills. We, therefore, describe the injury patterns, emergency flow and trauma outcome of patients injured in the Beirut port explosion. The clinical and system-level lessons learned can help prepare for the next disaster.

New Insights into the Application of 3D-Printing Technology in Hernia Repair

Abdominal hernia repair using prosthetic materials is among the surgical interventions most widely performed worldwide. These materials, or meshes, are implanted to close the hernial defect, reinforcing the abdominal muscles and reestablishing mechanical functionality of the wall. Meshes for hernia repair are made of synthetic or biological materials exhibiting multiple shapes and configurations. Despite the myriad of devices currently marketed, the search for the ideal mesh continues as, thus far, no device offers optimal tissue repair and restored mechanical performance while minimizing postoperative complications. Additive manufacturing, or 3D-printing, has great potential for biomedical applications. Over the years, different biomaterials with advanced features have been successfully manufactured via 3D-printing for the repair of hard and soft tissues. This technological improvement is of high clinical relevance and paves the way to produce next-generation devices tailored to suit each individual patient. This review focuses on the state of the art and applications of 3D-printing technology for the manufacture of synthetic meshes. We highlight the latest approaches aimed at developing improved bioactive materials (e.g., optimizing antibacterial performance, drug release, or device opacity for contrast imaging). Challenges, limitations, and future perspectives are discussed, offering a comprehensive scenario for the applicability of 3D-printing in hernia repair.

Further structural characterization of ovine forestomach matrix and multi-layered extracellular matrix composites for soft tissue repair.

Decellularized extracellular matrix (dECM)–based biomaterials are of great clinical utility in soft tissue repair applications due to their regenerative properties. Multi-layered dECM devices have been developed for clinical indications where additional thickness and biomechanical performance are required. However, traditional approaches to the fabrication of multi-layered dECM devices introduce additional laminating materials or chemical modifications of the dECM that may impair the biological functionality of the material. Using an established dECM biomaterial, ovine forestomach matrix, a novel method for the fabrication of multi-layered dECM constructs has been developed, where layers are bonded via a physical interlocking process without the need for additional bonding materials or detrimental chemical modification of the dECM. The versatility of the interlocking process has been demonstrated by incorporating a layer of hyaluronic acid to create a composite material with additional biological functionality. Interlocked composite devices including hyaluronic acid showed improved in vitro bioactivity and moisture retention properties.