Exosomes Secreted During Myogenic Differentiation of Human Fetal Cartilage-Derived Progenitor Cells Promote Skeletal Muscle Regeneration through miR-145-5p.

BACKGROUND: Currently, there is no apparent treatment for sarcopenia, which is characterized by diminished myoblast function. We aimed to manufacture exosomes that retain the myogenic differentiation capacity of human fetal cartilage-derived progenitor cells (hFCPCs) and investigate their muscle regenerative efficacy in myoblasts and a sarcopenia rat model. METHODS: The muscle regeneration potential of exosomes (F-Exo) secreted during myogenic differentiation of hFCPCs was compared to human bone marrow mesenchymal stem cells-derived (hBMSCs) exosomes (B-Exo) in myoblasts and sarcopenia rat model. The effect of F-Exo was analyzed through known microRNAs (miRNAs) analysis. The mechanism of action of F-Exo was confirmed by measuring the expression of proteins involved in the Wnt signaling pathway. RESULTS: F-Exo and B-Exo showed similar exosome characteristics. However, F-Exo induced the expression of muscle markers (MyoD, MyoG, and MyHC) and myotube formation in myoblasts more effectively than B-Exo. Moreover, F-Exo induced greater increases in muscle fiber cross-sectional area and muscle mass compared to B-Exo in a sarcopenia rat. The miR-145-5p, relevant to muscle regeneration, was found in high concentrations in the F-Exo, and RNase pretreatment reduced the efficacy of exosomes. The effects of F-Exo on the expression of myogenic markers in myoblasts were paralleled by the miR-145-5p mimics, while the inhibitor partially negated this effect. F-Exo was involved in the Wnt signaling pathway by enhancing the expression of Wnt5a and ß-catenin. CONCLUSION: F-Exo improved muscle regeneration by activating the Wnt signaling pathway via abundant miR-145-5p, mimicking the remarkable myogenic differentiation potential of hFCPCs.

Controlled posterior condylar milling technique for unicompartmental knee arthroplasty minimises tibia resection during gap balancing: Short-term clinical results.

PURPOSE: The purpose of this study was to demonstrate the clinical utility of controlled posterior condylar milling (CPCM) in gap balancing while minimally resecting the tibia during fixed-bearing unicompartmental knee arthroplasty (UKA). METHODS: This study is a retrospective cohort study. Patients who underwent medial UKA for isolated medial compartment osteoarthritis with a minimum follow-up of 2 years were included. The patients were divided into two groups: the conventional group (n = 56) and the CPCM group (n = 66). In the CPCM group, the proximal tibia was resected at the level of the distal end of the subchondral bone. If the flexion gap was tighter than extension, the posterior condyle was additionally milled to adjust gap tightness. Standing knee X-ray and scanogram were used to evaluate alignment and tibia resection amount. Range of motion (ROM) and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) scores were used to evaluate clinical outcomes. RESULTS: The CPCM group showed significantly smaller tibia resection (3.6 ± 1.9 mm) compared to the conventional group (5.2 ± 2.7 mm) (p < 0.001). Postoperative ROM (133.0 ± 8.3°, 135.2 ± 7.2°, n.s.) and WOMAC (19.3 ± 13.6, 23.6 ± 17.7, n.s.) were not significantly different between the two groups. Postoperative periprosthetic fractures occurred in two patients in conventional group, while the CPCM group had no periprosthetic fractures. CONCLUSION: The CPCM technique may be a simple and useful intraoperative technique that can achieve minimal tibia resection and promising clinical outcomes while easily adjusting gap tightness between flexion and extension during medial fixed-bearing UKA. LEVEL OF EVIDENCE: Level III.

Fixed-Bearing Unicompartmental Knee Arthroplasty in Tibia Vara Knees Results in Joint Surface Malalignment and Varus Joint Line Obliquity, but Does Not Affect Functional Outcomes at Greater Than 5 Years Follow-Up.

BACKGROUND: This study aimed to investigate the clinical outcomes of fixed-bearing medial unicompartmental knee arthroplasty (UKA) for tibia vara knees and the associated changes in joint space malalignment (JSM) and joint line obliquity (JLO). METHODS: We retrospectively analyzed a consecutive group of 100 patients who underwent fixed-bearing medial UKA with a preoperative medial proximal tibia angle (MPTA) ≥86° (n = 50) and MPTA <86° (n = 50) and who had a minimum 5-year follow-up. Radiological parameters, including the hip-knee-ankle angle, MPTA, and the postoperative JSM and JLO, were measured. Functional evaluation was performed using the range of motion, visual analog scale, Knee Society Knee Score, Knee Society Function Score, and Western Ontario and McMaster Universities Osteoarthritis Index score. RESULTS: The MPTA <86° group showed significantly higher postoperative JLO (91.8 versus 90.4°, respectively; P = .002) and JSM (6.1 versus 4.2°, respectively; P = .026) compared to the MPTA ≥86° group. Functional outcomes, including range of motion, visual analog scale, Knee Society Knee Score, Knee Society Function Score, and Western Ontario and McMaster Universities Osteoarthritis Index scores, were not significantly different between the 2 groups. CONCLUSIONS: Fixed-bearing medial UKA is a safe and effective surgical option for patients who have tibia vara knees, as an increase in JLO and JSM postoperatively does not have a clinically relevant impact, even after a minimum 5-year follow-up.

Synovium-Derived Mesenchymal Stem Cell-Based Scaffold-Free Fibrocartilage Engineering for Bone-Tendon Interface Healing in an Anterior Cruciate Ligament Reconstruction Model.

BACKGROUND: Current tendon and ligament reconstruction surgeries rely on scar tissue healing which differs from native bone-to-tendon interface (BTI) tissue. We aimed to engineer Synovium-derived mesenchymal stem cells (Sy-MSCs) based scaffold-free fibrocartilage constructs and investigate in vivo bone-tendon interface (BTI) healing efficacy in a rat anterior cruciate ligament (ACL) reconstruction model. METHODS: Sy-MSCs were isolated from knee joint of rats. Scaffold-free sy-MSC constructs were fabricated and cultured in differentiation media including  TGF-ß-only, CTGF-only, and TGF-ß + CTGF. Collagenase treatment on tendon grafts was optimized to improve cell-to-graft integration. The effects of fibrocartilage differentiation and collagenase treatment on BTI integration was assessed by conducting histological staining, cell adhesion assay, and tensile testing. Finally, histological and biomechanical analyses were used to evaluate in vivo efficacy of fibrocartilage construct in a rat ACL reconstruction model. RESULTS: Fibrocartilage-like features were observed with in the scaffold-free sy-MSC constructs when applying TGF-ß and CTGF concurrently. Fifteen minutes collagenase treatment increased cellular attachment 1.9-fold compared to the Control group without affecting tensile strength. The failure stress was highest in the Col + D + group (22.494 ± 13.74 Kpa) compared to other groups at integration analysis in vitro. The ACL Recon + FC group exhibited a significant 88% increase in estimated stiffness (p = 0.0102) compared to the ACL Recon group at the 4-week postoperative period. CONCLUSION: Scaffold-free, fibrocartilage engineering together with tendon collagenase treatment enhanced fibrocartilaginous BTI healing in ACL reconstruction.

Suprapatellar intramedullary nail combined with screw fixation has comparable surgical outcomes to minimally invasive locking plate fixation in ipsilateral tibial plateau and shaft fractures.

PURPOSE: To compare union rate, union time, alignment, and complication rate in ipsilateral tibia plateau and shaft fractures treated via suprapatellar intramedullary nailing with screw fixation and minimally invasive locking plate fixation. MATERIALS AND METHODS: A retrospective study was conducted on 48 patients who underwent minimally invasive plate fixation (n = 35) or suprapatellar intramedullary nailing with screw fixation (n = 13), for the treatment of ipsilateral tibial plateau and shaft fractures with at least 1-year follow-up. Union rate, union time, radiologic alignment, and complication rate such as malalignment, nonunion, and fracture-related infection (FRI) were investigated. RESULTS: Demographic data were not different between the two groups. Coronal plane alignment was 0.17 ± 4.23 in the plate group and -0.48 ± 4.17 in the intramedullary nail group (p = 0.637). Sagittal plane alignment was -0.13 ± 5.20 in the plate group and -1.50 ± 4.01 in the suprapatellar intramedullary nail group (p = 0.313). Coronal and sagittal malalignment recorded equal results: (p > 0.99), FRI (p = 0.602), nonunion and union times recorded (p = 0.656) and (p = 0.683, 0.829), respectively, and showed no significant difference between the two groups. CONCLUSION: Suprapatellar intramedullary nailing with screw fixation had similar surgical outcomes with minimally invasive locking plate fixation in ipsilateral tibial plateau and shaft fractures in terms of union rate, union time, alignment, and complication rate. Thus, frequent use of intramedullary nailing combined with screw fixation is anticipated in patients with ipsilateral tibial plateau and shaft fractures when the soft tissue condition is not desirable. LEVEL OF EVIDENCE: Level III.

Rotational stability can be enhanced in revision anterior cruciate ligament reconstruction using the over-the-top augmentation technique compared to single bundle technique.

PURPOSE: Revision anterior cruciate ligament (ACL) reconstruction is technically challenging due to mispositioned tunnels, bone loss, and tunnel enlargement, which may compromise graft fixation and result in failure. To obtain firm graft fixation and strength in one stage, we utilized an over-the-top augmentation technique using an Achilles tendon allograft in revision ACL reconstruction (OA-ACLR). This study compared OA-ACLR with single-bundle ACL reconstruction (SB-ACLR). We hypothesized that OA-ACLR would enhance the postoperative knee joint rotational stability. METHODS: We retrospectively analyzed 47 patients who underwent revisional OA-ACLR and 48 who underwent primary SB-ACLR with minimum follow-up of 6 months. Knee instability was evaluated with the anterior drawer, Lachman, and pivot shift tests preoperatively and at the final follow-up. Side-to-side differences were compared with the non-affected side at the final follow-up. Function was evaluated using the IKDC subjective and Lysholm knee scores preoperatively and at the final follow-up. RESULTS: The groups did not differ in terms of sex, age, BMI, and etiology. There were no significant differences in concomitant surgical procedures, such as meniscectomy and meniscus repair, between the two groups (p = 0.335, > 0.99). Both groups significantly improved in the anterior drawer, Lachman, pivot shift tests, and IKDC and Lysholm knee scores after surgery (all p < 0.001). The OA-ACLR group showed significantly higher rotational stability in the pivot shift test than the SB-ACLR group (p = 0.017). The postoperative side-to-side difference, the IKDC and Lysholm scores showed no significant differences between the groups (p = 0.34, 0.301, 0.438). CONCLUSIONS: OA-ACLR showed enhanced rotational stability with pivot shift test compared to SB-ACLR. It may be considered a useful alternative for revision ACL reconstruction.

Comparison of suprapatellar intramedullary nailing versus minimal invasive locked plating for proximal tibia fractures.

PURPOSE: To compare the radiological alignment, union time, union rate, and complication rate between suprapatellar intramedullary nails and minimally invasive locking plate fixation in the treatment of proximal tibial fractures. MATERIALS AND METHODS: We retrospectively analyzed 103 patients who underwent plate fixation (n = 50) or suprapatellar intramedullary nailing (n = 53) for proximal tibial fractures involving the meta-diaphyseal junction between November 2015 and October 2020 at our institution. The union rate, union time, radiologic alignments, and complications, such as malalignment, nonunion, and deep infection, were investigated. RESULTS: The demographic data did not differ between the plate and suprapatellar intramedullary nail groups. The alignment of the coronal plane was 0.24 ± 3.19 in the plate group and - 0.49 ± 2.22 in the intramedullary nail group (p = 0.196). Sagittal plane alignment was - 0.29 ± 4.97 in the plate group and 0.24 ± 4.12 in the intramedullary nail group (p = 0.571), and coronal malalignment (p = 0.196), sagittal malalignment (p = 0.57), deep infection (p = 0.264), nonunion (p = 0.695), union time (p = 0.329), and final union rate (p = 0.699) were not significantly different between groups. CONCLUSION: Compared with the minimally invasive locking compression plate group, the suprapatellar intramedullary nail group yielded comparable results in terms of radiological alignment and complications. Considering that proximal tibial fractures are associated with high-energy trauma and severe soft tissue damage, we believe that a suprapatellar intramedullary nail may be a good alternative. LEVEL OF EVIDENCE: Level III.

Selective Extracellular Matrix Guided Mesenchymal Stem Cell Self-Aggregate Engineering for Replication of Meniscal Zonal Tissue Gradient in a Porcine Meniscectomy Model.

Degenerative meniscus tears (DMTs) are prevalent findings in osteoarthritic knees, yet current treatment is mostly limited to arthroscopic partial meniscectomy rather than regeneration, which further exacerbates arthritic changes. Translational research regarding meniscus regeneration is hindered by the complex, composite nature of the meniscus which exhibit a gradient from inner cartilage-like tissue to outer fibrous tissue, as well as engineering hurdles often requiring growth factors and cross-linking agents. Here, a meniscus zonal tissue gradient is proposed using zone-specific decellularized meniscus extracellular matrix (DMECM) and autologous synovial mesenchymal stem cells (SMSC) via self-aggregation without the use of growth factors or cross-linking agents. Combination with zone-specific DMECM during self-aggregation of MSCs forms zone-specific meniscus tissue that reflects the respective DMECM harvest site. The implantation of these constructs leads to the regeneration of meniscus tissue resembling the native meniscus, demonstrating inner cartilaginous and outer fibrous characteristics as well as recovery of native meniscal microarchitecture in a porcine partial meniscectomy model at 6 months. In all, the findings offer a potential regenerative therapy for DMTs that may improve current partial meniscectomy-based patient care.

Effects of glycosaminoglycan content in extracellular matrix of donor cartilage on the functional properties of osteochondral allografts evaluated by micro-CT non-destructive analysis.

Osteochondral allograft (OCA) is an important surgical procedure used to repair extensive articular cartilage damage. It is known that chondrocyte viability is crucial for maintaining the biochemical and biomechanical properties of OCA, which is directly related to the clinical success of the operation and is the only standard for preoperative evaluation of OCA. However, there is a lack of systematic research on the effect of the content of cellular matrix in OCA cartilage tissue on the efficacy of transplantation. Therefore, we evaluated the effect of different GAG contents on the success of OCA transplantation in a rabbit animal model. Each rabbit OCA was treated with chondroitinase to regulate glycosaminoglycan (GAG) content in the tissue. Due to the different action times of chondroitinase, they were divided into 4 experimental groups (including control group, 2h, 4h, and 8h groups). The treated OCAs of each group were used for transplantation. In this study, transplant surgery effects were assessed using micro-computed tomography (µCT) and histological analysis. Our results showed that tissue integration at the graft site was poorer in the 4h and 8h groups compared to the control group at 4 and 12 weeks in vivo, as were the compressive modulus, GAG content, and cell density reduced. In conclusion, we evaluated the biochemical composition of OCAs before and after surgery using µCT analysis and demonstrated that the GAG content of the graft decreased, it also decreased during implantation; this resulted in decreased chondrocyte viability after transplantation and ultimately affected the functional success of OCAs.

Long-Term Ultrasonographic and Histologic Changes in Acellular Dermal Matrix in Implant-Based Breast Reconstructions.

BACKGROUND: Acellular dermal matrix (ADM) is composed of extracellular matrix (ECM) and is widely used in implant-based breast reconstructions. However, long-term changes in the ADM around implants have not been established. This study aimed to investigate long-term changes in the ADM covering breast implants using serial ultrasound and histologic evaluations. METHODS: The authors evaluated the ultrasound results of 145 patients who underwent implant-based breast reconstructions with ADM coverings. The ultrasound results obtained within 18 months of surgery and those obtained 5 years postoperatively were analyzed to determine the change in ADM thickness. For histologic analysis, the ADM was harvested from 30 patients who underwent secondary breast surgery. Histologic features of the ECM and cellular components within the ADM were compared at specific intervals from ADM implantation and the second operation (early ADM group, <18 months; late ADM group, >5 years postoperatively). RESULTS: The ADM thickness on ultrasound examination was significantly decreased in the late ADM group compared with that in the early ADM group ( P < 0.001). Histologic analyses revealed that the late ADM group had less thickness with lower ECM levels versus the early ADM group. Increased infiltration of host cells, such as vascular endothelial cells, myofibroblasts, and immune cells, occurred in the late ADM group. CONCLUSIONS: Implanted ADMs underwent gradual thinning over time, in addition to ECM reduction and infiltration of host cells. These findings are useful in understanding the natural course of ADMs currently used in implant-based breast reconstructions. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Risk of Dementia in Newly Diagnosed Glaucoma: A Nationwide Cohort Study in Korea.

PURPOSE: To investigate the risk of dementia in participants with newly diagnosed glaucoma. DESIGN: A nationwide cohort study using authorized data provided by the Korean National Health Insurance Service (NHIS). PARTICIPANTS: A total of 788 961 participants aged ≥ 45 years in 2006, who did not have dementia or glaucoma between 2002 and 2005, were included. METHODS: Data were collected from a nationwide population-based retrospective cohort study using the Korean NHIS database. From January 2006 to December 2017, participants were tracked for the diagnosis of glaucoma or dementia using claims data. The prospective association between newly diagnosed glaucoma and the risk of dementia was investigated using a multivariable Cox proportional hazard model adjusted for age, sex, behavioral factors, and systemic and ocular comorbidities. MAIN OUTCOME MEASURES: Hazard ratios (HRs) and 95% confidence intervals (CIs) for dementia development according to the parameters, including glaucoma diagnosis. RESULTS: Overall, 7.0% of the participants developed dementia after an average of 7.4 years. Newly diagnosed glaucoma was associated with a higher risk of dementia (HR, 1.89, 95% CI, 1.57-2.27) independent of age, sex, body mass index, income, smoking and drinking status, visual acuity, and other systemic comorbidities, such as diabetes, hypertension, stroke, and depression. Newly diagnosed glaucoma was associated with higher risk of AD but not VD. The risk of dementia in relation to glaucoma was higher in older participants (HR, 3.15 [≥ 65 years] vs. 1.56 [< 65 years], P < 0.0001). CONCLUSIONS: This nationwide cohort study found that individuals with newly diagnosed glaucoma were at a higher risk of developing dementia, particularly AD. This association was greater among older individuals in the studied population. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Implantation and tracing of green fluorescent protein-expressing adipose-derived stem cells in peri-implant capsular fibrosis.

BACKGROUND: Adipose-derived stem cells (ASCs) have been reported to reduce fibrosis in various tissues. In this study, we investigated the inhibitory role of ASCs on capsule formation by analyzing the histologic, cellular, and molecular changes in a mouse model of peri-implant fibrosis. We also investigated the fate and distribution of ASCs in the peri-implant capsule. METHODS: To establish a peri-implant fibrosis model, customized silicone implants were inserted into the dorsal site of C57BL/6 wild-type mice. ASCs were harvested from the fat tissues of transgenic mice that express a green fluorescent protein (GFP-ASCs) and then injected into the peri-implant space of recipient mice. The peri-implant tissues were harvested from postoperative week 2 to 8. We measured the capsule thickness, distribution, and differentiation of GFP-ASCs, as well as the cellular and molecular changes in capsular tissue following ASC treatment. RESULTS: Injected GFP-ASCs were distributed within the peri-implant capsule and proliferated. Administration of ASCs reduced the capsule thickness, decreased the number of myofibroblasts and macrophages in the capsule, and decreased the mRNA level of fibrogenic genes within the peri-implant tissue. Angiogenesis was enhanced due to trans-differentiation of ASCs into vascular endothelial cells, and tissue hypoxia was relieved upon ASC treatment. CONCLUSIONS: We uncovered that implanted ASCs inhibit capsule formation around the implant by characterizing a series of biological alterations upon ASC treatment and the fate of injected ASCs. These findings highlight the value of ASCs for future clinical applications in the prevention of capsular contracture after implant-based reconstruction surgery.

Aqueous microRNA profiling in age-related macular degeneration and polypoidal choroidal vasculopathy by next-generation sequencing.

Although many studies demonstrated the differences of clinical features, natural course, and response to treatment between typical age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV), differential microRNAs (miRNAs) expression in the aqueous humor (AH) between them has not been reported yet. We investigated the roles of miRNAs in the AH of patients with typical AMD and PCV using next-generation sequencing (NGS) and quantitative PCR (qPCR). Target genes and predicted pathways of miRNAs were investigated via pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes database. A total of 161 miRNAs from eyes with typical AMD and 185 miRNAs from eyes with PCV were differentially expressed. 33 miRNAs were commonly upregulated, and 77 miRNAs were commonly downregulated in both typical AMD and PCV groups. Among them, hsa-miR-140-5p, hsa-miR-374c-3p, and hsa-miR-200a-5p were differentially expressed and were predicted to regulate proteoglycans in cancer, p53 signaling pathway, Hippo signaling pathway, and adherens junction. The differential expression profiles and target gene regulation networks of AH miRNAs may contribute to the development of different pathological phenotypes in typical AMD and PCV. The results of this study provide novel insights into the pathogenesis, associated prognostic biomarkers, and therapeutic targets in AMD and PCV.

Dll4 Inhibition Promotes Graft Retention in Fat Grafting Enriched with Adipose-Derived Stem Cells.

Autologous fat grafting is among the safest and most effective treatments for soft-tissue restoration and augmentation, and many efforts have been made to improve its efficiency, including adipose-derived stem cell (ASC) supplementation. Here, we investigated the role of Notch ligand Delta-like ligand 4 (Dll4) in angiogenesis within grafted fat and its effect on graft retention, as well as the effect of Dll4 inhibition on ASC supplementation. Using a murine fat graft model, we investigated the expression of Dll4 in fat grafts and assessed the graft volume, vascularity, and perfusion within the graft, and ASC differentiation patterns depending on the blockade of Dll4. The underlying mechanism of Dll4 inhibition on ASC supplemented fat grafts was investigated using transcriptome analysis. Dll4 was highly expressed in vascular endothelial cells (ECs) within grafted fat, where Dll4-blocking antibody treatment-induced angiogenesis, promoting fat graft retention. In addition, its effect on fat graft retention was synergistically improved when ASCs were concomitantly supplemented. The expression of junctional proteins was increased in ECs, and inflammatory processes were downregulated in grafted fat upon ASC supplementation and Dll4 inhibition. Dll4 inhibition induced vascularization within the grafted fat, thereby promoting graft retention and exhibiting synergistic effects with concomitant ASC supplementation. This study serves as a basis for developing new potential therapeutic approaches targeting Dll4 to improve graft retention after cell-assisted transfer.

Circumferential Rim Augmentation Suture Around the Perimeniscal Capsule Decreases Meniscal Extrusion and Progression of Osteoarthritis in Rabbit Meniscus Root Tear Model.

BACKGROUND: We recently analyzed the joint capsule adjacent to the medial meniscus and found that the perimeniscal joint capsule has collagen fiber orientation similar to that of circumferential meniscal fibers, potentially playing a role in preventing extrusion. PURPOSE: To analyze the meniscal extrusion prevention potential of the circumferential rim augmentation suture around the perimeniscal capsule in a rabbit root tear model and analyze the biomechanical function in a porcine cadaveric knee. STUDY DESIGN: Controlled laboratory study. METHODS: Rabbit medial meniscus root tear models were divided into 3 experimental groups: root tear, root tear and suture repair, and root tear and circumferential rim augmentation suture. As for the circumferential rim augmentation suture procedure, a suture was placed to circumscribe the outer rim of the medial meniscus and passed through bone tunnels located at the tibial insertion of each root. After 4 and 8 weeks, meniscal extrusion was analyzed by micro-computed tomography, gross morphology, and histologic analysis of the medial femoral cartilage. For biomechanical analysis, porcine knees were divided into groups similar to rabbit experiments. Tibiofemoral contact parameters were assessed using a pressure mapping sensor system after applying a load of 200 N on the knee joint. RESULTS: The root tear and circumferential rim augmentation suture group showed less meniscal extrusion, less gap within the tear site, and less cartilage degeneration compared with other groups after 4 and 8 weeks of surgery in the rabbit root tear model. Biomechanical analysis showed the root tear and circumferential rim augmentation suture group had larger contact area and lower peak contact pressure compared with root tear and root tear and suture repair groups. CONCLUSION: The circumferential rim augmentation suture reduced the degree of meniscal extrusion while restoring meniscal function, potentially preventing progression of arthritis in a rabbit root tear model and porcine knee biomechanical analysis. CLINICAL RELEVANCE: The circumferential rim augmentation suture may be a novel augmentation option during root tear treatment.

Anti-adhesive effect of chondrocyte-derived extracellular matrix surface-modified with poly-L-lysine.

After an injury, soft tissue structures in the body undergo a natural healing process through specific phases of healing. Adhesions occur as abnormal attachments between tissues and organs through the formation of blood vessels and/or fibrinous adhesions during the regenerative repair process. In this study, we developed an adhesion-preventing membrane with an improved physical protection function by modifying the surface of chondrocyte-derived extracellular matrices (CECM) with anti-adhesion function. We attempted to change the negative charge of the CECM surface to neutral using poly-L-lysine (PLL) and investigated whether it blocked fibroblast adhesion to it and showed an improved anti-adhesion effect in animal models of tissue adhesion. The surface of the membrane was modified with PLL coating (PLL 10), which neutralized the surface charge. We confirmed that the surface characteristics except for the potential difference were maintained after the modification and tested cell attachment in vitro. Adhesion inhibition was identified in a peritoneal adhesion animal model at 1 week and in a subcutaneous adhesion model for 4 weeks. Neutralized CECM (N-CECM) suppressed fibroblast and endothelial cell adhesion in vitro and inhibited abdominal adhesions in vivo. The CECM appeared to actively inhibit the infiltration of endothelial cells into the injured site, thereby suppressing adhesion formation, which differed from conventional adhesion barriers in the mode of action. Furthermore, the N-CECM remained intact without degradation for more than 4 weeks in vivo and exerted anti-adhesion effects for a long time. This study demonstrated that PLL10 surface modification rendered a neutral charge to the polymer on the extracellular matrix surface, thereby inhibiting cell and tissue adhesion. Furthermore, this study suggests a means to modify extracellular matrix surfaces to meet the specific requirements of the target tissue in preventing post-surgical adhesions.

Cytokine and Growth Factor Analysis in Exfoliation Syndrome and Glaucoma.

Purpose: We compared cytokines, chemokines, and growth factors in the aqueous humor (AH) of patients with exfoliation syndrome (XFS), with exfoliation glaucoma (XFG), with primary open angle glaucoma (POAG), and healthy controls. Methods: AH samples were collected from 21 patients with XFS, 28 with XFG, 14 with POAG, and 17 healthy controls during routine cataract surgery. The protein levels of 21 cytokines and growth factors, together with TGF-ß1, 2, and 3, were quantified using the multiplex immunoassay. The levels of each protein in the four groups were compared using the Kruskal-Wallis test. Results: Among the 24 cytokines and growth factors, 16 were out of the detectable range in >50% of samples in at least one group; the remaining 8 cytokines and growth factors (IL-8, MIP-1α, fractalkine, Flt3 ligand, PDGF-AA, VEGF, TGF-ß1, and TGF-ß2) were included in the analysis. TGF-ß1 and TGF-ß2 levels were the highest in patients with XFG and those with POAG, respectively. Expression levels of the inflammatory chemokines IL-8, MIP-1α, and fractalkine, as well as levels of the immune cell growth factor Flt3 ligand, were significantly higher in the XFG group than in the other groups. The protein levels of PDGF-AA and VEGF were not significantly different among the 4 groups. Conclusions: Both TGF-ß1 and inflammatory cytokines were highly expressed in the AH of patients with XFG. Considering that the levels of these cytokines are increased by oxidative stress and that they regulate the extracellular matrix, they may also play a role in intraocular pressure elevation in XFG.

Motorized Shaver Harvest Results in Similar Cell Yield and Characteristics Compared With Rongeur Biopsy During Arthroscopic Synovium-Derived Mesenchymal Stem Cell Harvest.

PURPOSE: To compare cell yield and character of synovium-derived mesenchymal stem cell (SDMSC) harvested by 2 different techniques using rongeur and motorized shaver during knee arthroscopy. METHODS: This study was performed in 15 patients undergoing partial meniscectomy. Two different techniques were used to harvest SDMSCs in each patient from the synovial membrane at 2 different locations overlying the anterior fat pad, each within 1 minute of harvest time. Cell yield and proliferation rates were evaluated. Cell surface marker analysis was done after passage 2 (P2). Trilineage differentiation potential was evaluated by real-time quantitative polymerase chain reaction and histology. Statistical analysis between the 2 methods was done using the Mann-Whitney U test. RESULTS: Wet weight of total harvested tissue was 69.93 (± 20.02) mg versus 378.91 (± 168.87) mg for the rongeur and shaver group, respectively (P < .0001). Mononucleated cell yield was 3.32 (± 0.89) versus 3.18 (± 0.97) × 103 cells/mg, respectively (P = .67). Fluorescence-activated cell sorting analysis revealed similar SDMSC-related cell surface marker expression levels in both groups, with positive expression for CD44, CD73, CD90, and CD105 and decreased expression for CD34 and CD45. Both groups showed similar trilineage differentiation potential in histology. Chondrogenic (SOX9, ACAN, COL2), adipogenic (LPL, PLIN1, PPAR-γ), and osteogenic (OCN, OSX, RUNX2) gene marker expression levels also were similar between both groups. CONCLUSIONS: No difference was observed between rongeur biopsy and motorized shaver harvest methods regarding SDMSC yield and cell characteristics. CLINICAL RELEVANCE: The current study shows that both rongeur and motorized shaver harvest are safe and effective methods for obtaining SDMSCs. Motorized shaver harvest results in higher volume of tissue acquisition per time, thereby leading to higher number of SDMSCs which may be useful during clinical application.

Effect of connective tissue growth factor gene editing using adeno-associated virus-mediated CRISPR-Cas9 on rabbit glaucoma filtering surgery outcomes.

Suppressing excessive wound healing responses is critical to ensure surgical success in glaucoma filtration surgery (GFS). Currently used adjunctive materials can lead to side effects due to the nonselectivity in cell inhibition and may require repeated applications. The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system may become a compelling opportunity in glaucoma surgery due to its high selectivity and permanent effect. Connective tissue growth factor (CTGF) is one of the most potent stimulators of tissue fibrosis in the eye. Therefore, we tested the effect of CTGF suppression using the CRISPR-Cas9 system on GFS fibrosis. We used an adeno-associated virus (AAV)-CRISPR-Cas9 system and confirmed successful CTGF suppression was achieved in fibroblasts in vitro through western blot analysis and deep sequencing. In the in vivo intereye-comparison rabbit GFS model, CRISPR-CTGF-treated eyes showed significantly better survival of the surgery site, less subconjunctival fibrosis, limited collagen deposition, and reduced cellularity than untreated eyes. Our results suggest a new possibility of CRISPR-Cas9-mediated CTGF suppression to improve human GFS outcomes.

The effect of distance between holes on the structural stability of subchondral bone in microfracture surgery: a finite element model study.

BACKGROUND: Microfracture is a surgical technique that involves creating multiple holes of 3-4 mm depth in the subchondral bone to recruit stem cells in the bone marrow to the lesion, inducing fibrocartilage repair and knee cartilage regeneration. Recently, it has been reported that increasing the exposed area of the lower cartilaginous bone (drilling a lot of holes) increases the outflow of stem cells, which is expected to affect the physical properties of the subchondral bone when the exposed area is large. The purpose of this study was to analyse the effect of the distance between the holes in the microfracture procedure on the structural stability of the osteochondral bone using a finite element method. METHODS: In this study, lateral aspects of the femoral knee, which were removed during total knee arthroplasty were photographed using microtomography. The model was implemented using a solitary walks program, which is a three-dimensional simplified geometric representation based on the basic microtomography data. A microfracture model was created by drilling 4 mm-deep holes at 1, 1.5, 2, 2.5, 3, 4, and 5 mm intervals in a simplified three-dimensional (3D) geometric femoral model. The structural stability of these models was analysed with the ABAQUS program. We compared the finite element model (FEM) based on the microtomography image and the simplified geometric finite element model. RESULTS: Von Mises stress of the subchondral bone plate barely increased, even when the distance between holes was set to 1 mm. Altering the distance between the holes had little impact on the structural stability of the subchondral bone plate. Safety factors were all below 1. CONCLUSIONS: Although we did not confirm an optimal distance between holes, this study does provide reference data and an epidemiological basis for determining the optimal distance between the holes used in the microfracture procedure.