Adhesion Formation Research Articles

Extracellular matrix stiffness mediates insulin secretion in pancreatic islets via mechanosensitive Piezo1 channel regulated Ca2+ dynamics

The pancreatic islet is surrounded by ECM that provides both biochemical and mechanical cues to the islet β-cell to regulate cell survival and insulin secretion. Changes in ECM composition and mechanical properties drive β-cell dysfunction in many pancreatic diseases. While several studies have characterized changes in islet insulin secretion with changes in substrate stiffness, little is known about the mechanotransduction signaling driving altered islet function in response to mechanical cues. We hypothesized that increasing matrix stiffness will lead to insulin secretion dysfunction by opening the mechanosensitive ion channel Piezo1 and disrupting intracellular Ca2+ dynamics in mouse and human islets. To test our hypothesis, mouse and human cadaveric islets were encapsulated in a biomimetic reverse thermal gel (RTG) scaffold with tailorable stiffness that allows formation of islet focal adhesions with the scaffold and activation of Piezo1 in 3D. Our results indicate that increased scaffold stiffness causes insulin secretion dysfunction mediated by increases in Ca2+ influx and altered Ca2+ dynamics via opening of the mechanosensitive Piezo1 channel. Additionally, inhibition of Piezo1 rescued glucose-stimulated insulin secretion (GSIS) in islets in stiff scaffolds. Overall, our results emphasize the role mechanical properties of the islet microenvironment plays in regulating function. It also supports further investigation into the modulation of Piezo1 channel activity to restore islet function in diseases like type 2 diabetes (T2D) and pancreatic cancer where fibrosis of the peri-islet ECM leads to increased tissue stiffness and islet dysfunction.

Identification of an FMNL2 Interactome by Quantitative Mass Spectrometry

Formin Homology Proteins (Formins) are a highly conserved family of cytoskeletal regulatory proteins that participate in a diverse range of cellular processes. FMNL2 is a member of the Diaphanous-Related Formin sub-group, and previous reports suggest FMNL2’s role in filopodia assembly, force generation at lamellipodia, subcellular trafficking, cell–cell junction assembly, and focal adhesion formation. How FMNL2 is recruited to these sites of action is not well understood. To shed light on how FMNL2 activity is partitioned between subcellular locations, we used biotin proximity labeling and proteomic analysis to identify an FMNL2 interactome. The interactome identified known and new FMNL2 interacting proteins with functions related to previously described FMNL2 activities. In addition, our interactome predicts a novel connection between FMNL2 and extracellular vesicle assembly. We show directly that FMNL2 protein is present in exosomes.

Advances in non-coding RNA in tendon injuries

Tendons serve as important weight-bearing structures that smoothly transfer forces from muscles to skeletal parts, allowing contracted muscle movements to be translated into corresponding joint movements. For body mechanics, tendon tissue plays an important role. If the tendons are damaged to varying degrees, it can lead to disability or pain in patients. That is to say, tendon injuries havea significant impact on quality of life and deserve our high attention. Compared to other musculoskeletal tissues, tendons are hypovascular and hypo-cellular, and therefore have a greater ability to heal, this will lead to a longer recovery period after injury or even disability, which will significantly affect the quality of life. There are many causes of tendon injury, including trauma, genetic factors, inflammation, aging, and long-term overuse, and the study of related mechanisms is of great significance. Currently, tendon there are different treatment modalities, like injection therapy and surgical interventions. However, they have a high failure rate due to different reasons, among which the formation of adhesions severely weakens the tissue strength, affecting the functional recovery and the patient’s quality of life. A large amount of data has shown that non coding RNAs can play a huge role in this field, thus attracting widespread attention from researchers from various countries. This review summarizes the relevant research progress on non-coding RNAs in tendon injuries, providing new ideas for a deeper understanding of tendon injuries and exploring new diagnostic and therapeutic approaches.

Hierarchical Chiral Calcium Silicate Hydrate Films Promote Vascularization for Tendon-to-Bone Healing.

Revascularization after rotator cuff repair is crucial for tendon-to-bone healing. The chirality of materials has been reported to influence their performance in tissue repair. However, data on the use of chiral structures to optimize biomaterials as a revascularization strategy remain scarce. Here, we develop calcium silicate hydrate (CSO) films with hierarchical chirality on the atomic to micrometer scale. Interestingly, levorotatory CSO (L-CSO) films promote the migration and angiogenesis of endothelial cells, whereas dextral and racemic CSO films do not induce the same effect. Molecular analysis demonstrate that L-chirality can be recognized by integrin receptors and lead to the formation of focal adhesion, which activates mechanosensitive ion channel transient receptor potential vanilloid 4 to conduct Ca2+ influx. Consequently, the phosphorylation of serum response factor is biased by Ca2+ influx to promote the vascular endothelial growth factor receptor 2 signaling pathway, resulting in enhanced angiogenesis. After implanted in a rat rotator cuff tear model, L-CSO films strongly enhance vascularization at the enthesis, promoting collagen maturation, increasing bone and fibrocartilage formation, and eventually improving the biomechanical strength. This study reveals the mechanism through which chirality influences angiogenesis in endothelial cells and provides a critical theoretical foundation for the clinical application of chiral biomaterials. This article is protected by copyright. All rights reserved.

Combination of miR-99b-5p and Enzalutamide or Abiraterone Synergizes the Suppression of EMT-Mediated Metastasis in Prostate Cancer.

Prostate cancer (PCa) is the most frequently diagnosed cancer and second leading cause of cancer deaths among American men. Androgen deprivation therapy (ADT) has been systemically applied as a first-line therapy for PCa patients. Despite the initial responses, the majority of patients under ADT eventually experienced tumor progression to castration-resistant prostate cancer (CRPC), further leading to tumor metastasis to distant organs. Therefore, identifying the key molecular mechanisms underlying PCa progression remains crucial for the development of novel therapies for metastatic PCa. Previously, we identified that tumor-suppressive miR-99b-5p is frequently downregulated in aggressive African American (AA) PCa and European American (EA) CRPC, leading to upregulation of mTOR, androgen receptor (AR), and HIF-1α signaling. Given the fact that mTOR and HIF-1α signaling are critical upstream pathways that trigger the activation of epithelial-mesenchymal transition (EMT), we hypothesized that miR-99b-5p may play a critical functional role in regulating EMT-mediated PCa metastasis. To test this hypothesis, a series of cell biology, biochemical, and in vitro functional assays (wound healing, transwell migration, cell/ECM adhesion, and capillary-like tube formation assays) were performed to examine the effects of miR-99b-5p mimic on regulating EMT-mediated PCa metastasis processes. Our results have demonstrated that miR-99b-5p simultaneously targets MTOR and AR signaling, leading to upregulation of E-cadherin, downregulation of Snail/N-cadherin/Vimentin, and suppression of EMT-mediated PCa metastasis. MiR-99b-5p alone and in combination with enzalutamide or abiraterone significantly inhibits the EMT-mediated metastasis of AA PCa and EA CRPC.

Structure-Based Optimization of Novel Sterol 24-C-Methyltransferase Inhibitors for the Treatment of Candida albicans Infections.

Interfering with sterol biosynthesis is an important strategy for developing safe and effective antifungal drugs. We previously identified compound H55 as an allosteric inhibitor of the fungal-specific C-24 sterol methyltransferase Erg6 for treating Candida albicans infections. Herein, 62 derivatives of H55 were designed and synthesized based on target-ligand interactions to identify more active candidates. Among them, d28 displayed the most potent antivirulence ability (MHIC50 = 0.25 μg/mL) by targeting Erg6, exhibiting an 8-fold increase in potency compared with H55. Moreover, d28 significantly outperformed H55 in inhibiting cell adhesion and biofilm formation, and exhibited minimal cytotoxicity and negligible potential to induce drug resistance. Of note, the coadministration of d28 and other sterol biosynthesis inhibitors, such as tridemorph or terbinafine, demonstrated a strong synergistic antifungal action in vitro and in vivo in a murine skin infection model. These results support the potential application of d28 in the treatment of C. albicans infections.

Current trends in the prevention of adhesions after zone 2 flexor tendon repair.

Treating flexor tendon injuries within the digital flexor sheath (commonly referred to as palmar hand zone 2) presents both technical and logistical challenges. Success hinges on striking a delicate balance between safeguarding the surgical repair for tendon healing and initiating early rehabilitation to mitigate the formation of tendon adhesions. Adhesions between tendon slips and between tendons and the flexor sheath impede tendon movement, leading to postoperative stiffness and functional impairment. While current approaches to flexor tendon repair prioritize maximizing tendon strength for early mobilization and adhesion prevention, factors such as pain, swelling, and patient compliance may impede postoperative rehabilitation efforts. Moreover, premature mobilization could risk repair failure, necessitating additional surgical interventions. Pharmacological agents offer a potential avenue for minimizing inflammation and reducing adhesion formation while still promoting normal tendon healing. Although some systemic and local agents have shown promising results in animal studies, their clinical efficacy remains uncertain. Limitations in these studies include the relevance of chosen animal models to human populations and the adequacy of tools and measurement techniques in accurately assessing the impact of adhesions. This article provides an overview of the clinical challenges associated with flexor tendon injuries, discusses current on- and off-label agents aimed at minimizing adhesion formation, and examines investigational models designed to study adhesion reduction after intra-synovial flexor tendon repair. Understanding the clinical problem and experimental models may serve as a catalyst for future research aimed at addressing intra-synovial tendon adhesions following zone 2 flexor tendon repair.

Spatial Transcriptomics Reveals Interaction of Injury-Derived Osteopontin with Mesothelial Cells in Serosal Scarring

Abstract Background Abdominal surgeries are often live-saving procedures. However, surgical interventions in the peritoneal cavity can cause the formation of post-surgical adhesions. These irreversible scar bands can trigger severe complications, such as chronic pelvic pain, small bowel obstruction, and infertility in women. Unfortunately, no effective treatment options for adhesion patients exist. On a cellular level, mesothelium-derived mesenchymal myofibroblasts have been identified as key pro-fibrotic players in adhesion formation. Aims Our aim is to study the molecular mechanisms of mesothelial cell recruitment in serosal repair and scarring, and thereby to identify potential targets for specific pharmacological anti-adhesion treatments. Methods We used a mesothelial cell reporter mouse system (Wt1CreERT2xRosa26tdTomato) and experimental injury models to study the differences of mesothelial cell recruitment to sites of adhesion formation in comparison to wound sites healing scar-free. To answer how injury zones affect the accumulation of mesothelial cells, we used untargeted spatial transcriptomics, identifying candidate molecules that were i) upregulated in adhesion formation sites, ii) not highly expressed in scar-free wound sites, and iii) had the potential to interact with mesothelial cells. Results We observed strong spatiotemporal correlation between accumulation of tdTomato+ cells and consecutive scarring. Spatial deconstruction of scar-specific signaling identified the candidate molecule Secreted phosphoprotein 1; an inflammatory zone-specific gene that encodes Osteopontin (OPN). After confirming increased OPN protein levels 7d post-surgery, we investigated its effect on adhesion formation using Spp1-/- mice. Indeed, Spp1-deficient mice showed significantly lower adhesion scores compared to control mice. Mechanistically, recombinant OPN had no chemotactic effect on primary human mesothelial cells, however triggered the upregulation of transcription factors associated with mesothelial-to-mesenchymal transition. Conclusion Together, these findings suggest a pivotal role for OPN in linking inflammation at injury sites with mesothelial cell recruitment in post-surgical serosal scarring. Therefore, OPN represents a potential target for novel pharmacological strategies to specifically inhibit scarring without affecting normal wound repair.

Biomechanics of Macrophages on Disordered Surface Nanotopography.

Macrophages are involved in every stage of the innate/inflammatory immune responses in the body tissues, including the resolution of the reaction, and they do so in close collaboration with the extracellular matrix (ECM). Simplified substrates with nanotopographical features attempt to mimic the structural properties of the ECM to clarify the functional features of the interaction of the ECM with macrophages. We still have a limited understanding of the macrophage behavior upon interaction with disordered nanotopography, especially with features smaller than 10 nm. Here, we combine atomic force microscopy (AFM), finite element modeling (FEM), and quantitative biochemical approaches in order to understand the mechanotransduction from the nanostructured surface into cellular responses. AFM experiments show a decrease of macrophage stiffness, measured with the Young's modulus, as a biomechanical response to a nanostructured (ns-) ZrOx surface. FEM experiments suggest that ZrOx surfaces with increasing roughness represent weaker mechanical boundary conditions. The mechanical cues from the substrate are transduced into the cell through the formation of integrin-regulated focal adhesions and cytoskeletal reorganization, which, in turn, modulate cell biomechanics by downregulating cell stiffness. Surface nanotopography and consequent biomechanical response impact the overall behavior of macrophages by increasing movement and phagocytic ability without significantly influencing their inflammatory behavior. Our study suggests a strong potential of surface nanotopography for the regulation of macrophage functions, which implies a prospective application relative to coating technology for biomedical devices.

Comparison of the effect of Everolimus, Prednisolone, and a combination of both on experimentally induced peritoneal adhesions in rats

Postoperative intra-abdominal adhesions represent a significant post-surgical problem. Its complications can cause a considerable clinical and cost burden. Herein, our study aimed to investigate the effect of Everolimus on peritoneal adhesion formation after inducing adhesions in rats. In this experimental study, adhesion bands were induced by intraperitoneal injection of 3 ml of 10% sterile talc solution in 64 male albino rats. The first group served as the control group. The second one received oral Prednisolone (1 mg/kg/day), the third received Everolimus (0.1 mg/kg/day), and group four received both drugs with similar dosages for four consecutive weeks. The formation of adhesion bands was qualitatively graded according to the Nair classification. The rats in the control group had extensive adhesions between the abdominal wall and the organs. Regarding substantial adhesion formation, 50% (8/16) of animals in the control group had substantial adhesions, while this rate in the groups receiving Prednisolone, Everolimus, and combination treatment was 31%, 31%, and 31%, respectively. Also, 68.75% (5/11) of the Prednisolone recipients had insubstantial adhesions, the same as Everolimus recipients, while in the combination group, 66.66% (10/15) rats had insubstantial adhesions. Everolimus demonstrated satisfactory results in reducing the rates of induced peritoneal adhesion in an experimental model, similar to Prednisolone and superior to a combination regime.

Outcomes of Septal Surgery with Nasal Packing Versus Quilting Sutures

Background: Septoplasty is a common surgical procedure used to correct a deviated nasal septum, which can cause nasal obstruction and impact respiratory function. Postoperative management traditionally includes nasal packing to prevent complications such as bleeding and hematoma, although it can be associated with discomfort and other complications. Quilting sutures have been proposed as an alternative technique to reduce these issues. Objective: To compare the postoperative outcomes of nasal packing versus quilting sutures in patients undergoing septoplasty. Methods: This prospective comparative cross-sectional study was conducted at the ENT unit of Combined Military Hospital Rawalpindi, Pakistan, after obtaining ethical approval. The sample size comprised 384 patients, with 192 in the nasal packing group and 192 in the quilting sutures group. Inclusion criteria included patients aged 18 to 70 years undergoing elective nasal septoplasty. Exclusion criteria were patients with nasal polyps, allergic rhinitis, diabetes, coagulation disorders, septal flap tears, those unfit for surgery, and those undergoing combined septoplasty and turbinate intervention. Patients were randomly assigned to either nasal packing or quilting sutures groups. Baseline characteristics, including age, gender, and BMI, were documented. Postoperative assessments were conducted at 48 hours, 1 week, and 3 months, evaluating pain using a visual analogue scale (VAS), bleeding, epiphora, dyspnea, hematoma, and adhesions. Data analysis was performed using SPSS version 26.0, with quantitative data represented as mean ± standard deviation and qualitative data as percentages and frequencies. Statistical significance was determined using chi-square and unpaired two-tailed Student’s t-tests, with p < 0.05 considered significant. Results: The mean age of participants was 34.37 ± 6.95 years. Gender distribution included 256 males (66.7%) and 128 females (33.3%). At 48 hours postoperatively, the nasal packing group had a higher mean pain score (5.96 ± 1.39) compared to the quilting sutures group (2.03 ± 1.05) (p < 0.001). Bleeding was more significant in the quilting sutures group (1.82 ± 0.60) than in the nasal packing group (1.27 ± 0.45) (p < 0.001). Epiphora and dyspnea were more common in the nasal packing group, with 48 patients (25%) and 81 patients (42.2%), respectively, compared to 8 patients (4.2%) and 6 patients (3.1%) in the quilting sutures group (p < 0.001). Hematoma occurrence was low and not significantly different between the groups. After 1 week, pain scores remained higher in the nasal packing group (1.45 ± 1.12) compared to the quilting sutures group (0.58 ± 0.79) (p < 0.001). At 3 months, pain scores were still higher in the nasal packing group (1.45 ± 1.12) compared to the quilting sutures group (0.58 ± 0.80) (p < 0.001), with no significant difference in adhesion formation. Conclusion: Quilting sutures resulted in lower postoperative pain and fewer complications compared to nasal packing in patients undergoing septoplasty, despite a slightly higher risk of bleeding. These findings suggest that quilting sutures may be a preferable alternative to nasal packing for postoperative management in septoplasty.

UFM1 inhibits hypoxia-induced angiogenesis via promoting proteasome degradation of HIF-1α

UFM1 inhibits hypoxia-induced angiogenesis via promoting proteasome degradation of HIF-1α

Intraoperative Hypertonic Saline Irrigation Preventing Seroma Formation in the Treatment of Axillary Bromhidrosis.

Subcutaneous seroma formation (SF) is commonly seen after axillary bromhidrosis surgeries and its treatment can be challenging and long. Current prevention methods are not consistent, and the treatment includes repeated aspirations and drains, both are associated with higher risk for infections. The purpose of this article is to present a novel and simple technique of intraoperative hypertonic saline irrigation (IHSI) to axillary bromhidrosis subcutaneous dead space, which prevents postoperative SF and enables early drain removal due to reduced secretions. From 2015 to 2022, we performed the intraoperative irrigation of the cavity through normal saline in 100 patients with primary axillary bromhidrosis. Through an incision approximately 3 cm long at the central axillary crease, the entire subcutaneous tissues containing apocrine glands were initially dissected with straight scissors within the axillary area, and then, the undermined apocrine glands were removed with curved scissors. The skin was defatted to become a full-thickness skin flap. Any suspected hemorrhagic spots were immediately coagulated electrosurgically. Negative pressure drains were placed, and intraoperative irrigation of the cavity through the drains with 20 ml of NaCl 0.9% or NaCl 10% left at site for 10 min applies different saline solutions in the same patients. The volumeofdrainage on the 1st postoperative day was 6.54±0.36 mL for the group B, which was significantly less than 15.23±0.42 mL for the group A (p < 0.05). The time of drain removal for the group B was 24 h, which was shorter than 48 h for the group A. In group B, 4 percent of axillae showed significant SF postoperatively, which was lower than the 20 percent of axillae associated with the group A (p < 0.05). The rate of incision infection for the group B was 2 percent, which was significantly lower than the 6 percent of axillae in the group A (p < 0.05). Two percent of axillae showed skin edge necrosis postoperatively in the group B, which was lower than the 10 percent of axillae associated with the group A (p < 0.05). IHSI enhances adhesion formation and reduces secretion rate in subcutaneous dissection space after axillary bromhidrosis surgeries, therefore enables early drain removal and prevents SF, incision infection and skin edge necrosis. As a result, reducing the pain of patients, decreasing inconveniency and cost saving of multiple outpatient visits or additional surgery. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Multi-omics analysis of human tendon adhesion reveals that ACKR1-regulated macrophage migration is involved in regeneration

Tendon adhesion is a common complication after tendon injury with the development of accumulated fibrotic tissues without effective anti-fibrotic therapies, resulting in severe disability. Macrophages are widely recognized as a fibrotic trigger during peritendinous adhesion formation. However, different clusters of macrophages have various functions and receive multiple regulation, which are both still unknown. In our current study, multi-omics analysis including single-cell RNA sequencing and proteomics was performed on both human and mouse tendon adhesion tissue at different stages after tendon injury. The transcriptomes of over 74 000 human single cells were profiled. As results, we found that SPP1+ macrophages, RGCC+ endothelial cells, ACKR1+ endothelial cells and ADAM12+ fibroblasts participated in tendon adhesion formation. Interestingly, despite specific fibrotic clusters in tendon adhesion, FOLR2+ macrophages were identified as an antifibrotic cluster by in vitro experiments using human cells. Furthermore, ACKR1 was verified to regulate FOLR2+ macrophages migration at the injured peritendinous site by transplantation of bone marrow from Lysm-Cre;R26RtdTomato mice to lethally irradiated Ackr1−/− mice (Ackr1−/− chimeras; deficient in ACKR1) and control mice (WT chimeras). Compared with WT chimeras, the decline of FOLR2+ macrophages was also observed, indicating that ACKR1 was specifically involved in FOLR2+ macrophages migration. Taken together, our study not only characterized the fibrosis microenvironment landscape of tendon adhesion by multi-omics analysis, but also uncovered a novel antifibrotic cluster of macrophages and their origin. These results provide potential therapeutic targets against human tendon adhesion.

Essential role of glycoprotein Ibα in platelet activation

AbstractGlycoprotein Ibα (GPIbα), the ligand-binding subunit of platelet GPIb-IX complex, interacts with von Willebrand factor (VWF) exposed at the injured vessel wall, initiating platelet adhesion, activation, hemostasis, and thrombus formation. The cytoplasmic tail of GPIbα interacts with 14-3-3ζ, regulating the VWF-GPIbα–elicited signal transduction and VWF binding function of GPIbα. However, we unexpectedly found that the GPIbα–14-3-3ζ association, beyond VWF-dependent function, is essential for general platelet activation. We found that the GPIbα cytoplasmic tail peptide MPαC, a potential GPIbα inhibitor, by itself induced platelet aggregation, integrin αIIbβ3 activation, granule secretion, and phosphatidylserine (PS) exposure. Conversely, the deletion of the cytoplasmic tail of GPIbα in mouse platelets (10aa−/−) decreased platelet aggregation, integrin αIIbβ3 activation, granule secretion, and PS exposure induced by various physiological agonists. Phosphoproteome-based kinase activity profiling revealed significantly upregulated protein kinase C (PKC) activity in MPαC-treated platelets. MPαC-induced platelet activation was abolished by the pan-PKC inhibitor and PKCα deletion. Decreased PKC activity was observed in both resting and agonist-stimulated 10aa−/− platelets. GPIbα regulates PKCα activity by sequestering 14-3-3ζ from PKCα. In vivo, the deletion of the GPIbα cytoplasmic tail impaired mouse hemostasis and thrombus formation and protected against platelet-dependent pulmonary thromboembolism. Therefore, our findings demonstrate an essential role for the GPIbα cytoplasmic tail in regulating platelet general activation and thrombus formation beyond the VWF–GPIbα axis.

Advancing Novel Strategies against Post-surgical Tendon Adhesion Bands, Exploring New Frontiers.

Current interest in adhesion formation stems from its global impact on the function and quality of life, spanning a spectrum of subtle impairments to significant disabilities, based on the affected area and the extent of adhesion. Yet therapeutic agents are restricted to prophylactic anti-inflammatories, revision surgeries, and biological and physical techniques, none of which grant a decent outcome. Recent advancements in tissue- engineered biomaterials, drug delivery systems, and fabricating technologies such as nanoparticles, hydrogels, and weaving or braiding demonstrate potential for improved outcomes. However, none of the mentioned methods have reliable outcomes, thus this study aims to elucidate the mechanisms involved in the pathophysiology of tendon adhesion and post-surgical adhesion band formation (PSAB), with a closer look at inflammatory pathways stimulating the process. This article consolidates information on diverse therapeutic and prophylactic methods and cutting-edge technologies, aiming to provide a comprehensive update on this topic, and providing researchers an avenue for new and innovative ideas for further investigations.

Fabrication and Characterization of Colorectal Cancer Organoids from SW1222 Cell Line in Ultrashort Self-Assembling Peptide Matrix.

Ultrashort self-assembling peptides (SAPs) can spontaneously form nanofibers that resemble the extracellular matrix. These fibers allow the formation of hydrogels that are biocompatible, biodegradable, and non-immunogenic. We have previously proven that SAPs, when biofunctionalized with protein-derived motifs, can mimic the extracellular matrix characteristics that support colorectal organoid formation. These biofunctional peptide hydrogels retain the original parent peptide's mechanical properties, tunability, and printability while incorporating cues that allow cell-matrix interactions to increase cell adhesion. This paper presents the protocols needed to evaluate and characterize the effects of various biofunctional peptide hydrogels on cell adhesion and lumen formation using an adenocarcinoma cancer cell line able to form colorectal cancer organoids cost-effectively. These protocols will help evaluate biofunctional peptide hydrogel effects on cell adhesion and luminal formation using immunostaining and fluorescence image analysis. The cell line used in this study has been previously utilized for generating organoids in animal-derived matrices.

Auxin signaling in the cambium promotes tissue adhesion and vascular formation during Arabidopsis graft healing.

The strong ability of plants to regenerate wounds is exemplified by grafting when two plants are cut and joined together to grow as one. During graft healing, tissues attach, cells proliferate, and the vasculatures connect to form a graft union. The plant hormone auxin plays a central role, and auxin-related mutants perturb grafting success. Here, we investigated the role of individual cell types and their response to auxin during Arabidopsis (Arabidopsis thaliana) graft formation. By employing a cell-specific inducible misexpression system, we blocked auxin response in individual cell types using the bodenlos mutation. We found that auxin signaling in procambial tissues was critical for successful tissue attachment and vascular differentiation. In addition, we found that auxin signaling was required for cell divisions of the procambial cells during graft formation. Loss of function mutants in cambial pathways also perturbed attachment and phloem reconnection. We propose that cambial and procambial tissues drive tissue attachment and vascular differentiation during successful grafting. Our study thus refines our knowledge of graft development and furthers our understanding of the regenerative role of the cambium.

Laparoscopy Compared With Laparotomy as a Risk Factor for Intra-abdominal Adhesion Formation [ID 2683454

INTRODUCTION: The objective of this study is to compare the incidence and severity of abdominal and pelvic adhesions after laparoscopy versus laparotomy. METHODS: All patients undergoing laparoscopic surgery with study staff were included in this IRB-approved study. Postoperatively, surgeons filled out data collection forms to capture pertinent details. Patients with a history of only laparoscopy or only laparotomy were included, whereas those with known past inflammatory events, no prior surgeries, or a combination of laparoscopic and open procedures were excluded. RESULTS: Seventy-six laparoscopy-only and 83 laparotomy-only patients were included in this cohort. Adhesions were noted in 31 laparoscopy patients (40.8%) versus 74 laparotomy patients (89.2%; P&lt;.001). Filmy adhesions were noted in 22 laparoscopy patients (28.9%) versus 37 laparotomy patients (44.6%), without statistical significance (P=.06098). Higher-grade adhesions were significantly more prominent in the laparotomy group. Laparotomy group had significantly more dense adhesions (55.4% versus 11.8%; P&lt;.001) and cohesive adhesions with attached surfaces (32.5% versus 10.5%; P=.001614). By location, the laparotomy group had significantly more periumbilical adhesions (34.9% versus 3.9%; P&lt;.001). Adhesiolysis time was shorter in laparoscopy (3 versus 10 minutes; P=.008439). CONCLUSION: Our data demonstrate that not only does laparotomy present a greater risk for adhesion formation than laparoscopy, but they are more likely to be present in the periumbilical area and the quality of those adhesions are significantly more likely to be dense and/or cohesive in nature, subjecting patients to more risk and requiring more surgical time to address.

Difference in formation of a dental multi-species biofilm according to substratum direction

ObjectivesThe aim of this study was to investigate the difference in dental biofilm formation according to substratum direction, using an artificial biofilm model. MethodsA three-species biofilm, consisting of Streptococcus mutans, Streptococcus oralis, and Actinomyces naeslundii, was formed on saliva-coated hydroxyapatite (sHA) discs oriented in three directions: downward (the discs placed in the direction of gravity), vertical (the discs placed parallel to the direction of gravity), and upward (the discs placed in opposite direction of gravity). The biofilms at 22h and 46h of age were analyzed using microbiological and biochemical methods, fluorescence-based assays, and scanning electron microscopy to investigate difference in bacterial adhesion, early and mature biofilm formation. ResultsThe biofilms formed in the upward direction displayed the most complex structure, with the highest number and biovolume of bacteria, as well as the lowest pH conditions at both time points. The vertical and downward directions, however, had only scattered and small bacterial colonies. In the 22-h-old biofilms, the proportion of S. oralis was similar to, or slightly higher than, that of S. mutans in all directions of substratum surfaces. However, in the 46-h-old biofilms, S. mutans became the dominant bacteria in all directions, especially in the vertical and upward directions. ConclusionsThe direction of the substratum surface could impact the proportion of bacteria and cariogenic properties of the multi-species biofilm. Biofilms in an upward direction may exhibit a higher cariogenic potential, followed by those in the vertical and downward directions, which could be related to gravity.