Platelet-rich plasma pretreatment protects anterior cruciate ligament fibroblasts correlated with PI3K-Akt-mTOR pathway under hypoxia condition.

Background: /Objective: Biological factors such as platelet-rich plasma (PRP) combined with anterior cruciate ligament (ACL) primary repair technology are used to treat ACL injury. However, the protective mechanism of PRP for ACL fibroblasts under hypoxia condition is still unknown. The aim of this study was to investigate the protective effect of PRP on ACL fibroblasts under hypoxia condition and illustrate the mechanism of PRP regulating the ACL fibroblasts under hypoxia condition.

Evaluation of animal models and methods for assessing shoulder function after rotator cuff tear: A systematic review.

Background And Objective: Restoring the shoulder function is a crucial demand of patients with rotator cuff (RC) tears. Most preclinical studies only focused on biological and mechanical measurements. Functional assessment was less investigated in the preclinical studies.

The 3D-Printed PLGA Scaffolds Loaded with Bone Marrow-Derived Mesenchymal Stem Cells Augment the Healing of Rotator Cuff Repair in the Rabbits.

The healing of tendon-bone in the rotator cuff is featured by the formation of the scar tissues in the interface after repair. This study aimed to determine if the 3D-printed poly lactic-co-glycolic acid (PLGA) scaffolds loaded with bone marrow-derived mesenchymal stem cells (BMSCs) could augment the rotator cuff repair in the rabbits. PLGA scaffolds were generated by the 3D-printed technology; Cell Counting Kit-8 assay evaluated the proliferation of BMSCs; the mRNA and protein expression levels were assessed by quantitative real-time polymerase chain reaction and western blot, respectively; immunohistology evaluated the rotator cuff repair; biomechanical characteristics of the repaired tissues were also assessed.

The effect of thermosensitive hydrogel platelet-rich-plasma complex in the treatment of partial tear of anterior cruciate ligament in rat model.

Background/objective: The treatment of anterior cruciate ligament (ACL) partial tear is controversial. The reconstructive surgery is invasive while the prevalence of subsequent insufficiency after conservative treatment has been reported to range from 11% to 62%. Therefore, a new method that promotes tissue regeneration is needed.

Risk factors for rotator cuff tendinopathy: A systematic review and meta-analysis.

Objectives: To conduct a systematic review and meta-analysis to identify risk and associated factors for symptomatic rotator cuff tendinopathy.

Data Sources: PubMed, CINAHL and Scopus were searched from inception to June 2017.

Study Selection: Participants presented with signs and symptoms suggestive of rotator cuff tendinopathy/tendinosis/tendinitis, shoulder impingement syndrome, or subacromial bursitis diagnosed by clinical tests and/or conventional imaging.

The non-reconstructive treatment of complete ACL tear with biological enhancement in clinical and preclinical studies: A systematic review.

Introduction: There is still controversy regarding the bio-enhanced non-reconstructive ACL treatment.

Materials And Methods: A search for articles in databases was performed in February 2017. The objective and subjective evaluations of clinical studies and biomechanical and histological data of preclinical studies were extracted.

Bioactive Tape With BMP-2 Binding Peptides Captures Endogenous Growth Factors and Accelerates Healing After Anterior Cruciate Ligament Reconstruction.

Background: The anterior cruciate ligament (ACL) has poor regenerative capacity, and an injury leads to loss of function, limiting quality of life and increasing the incidence of osteoarthritis. Surgical interventions can stabilize the joint and improve functional recovery. The delivery of growth factors (GFs) enhances the healing process; however, this is complex in its regulation, is high in costs, has side effects, and can only be accomplished with supraphysiological concentrations and thus is currently not clinically feasible.

Effects of Redox Modulation on Cell Proliferation, Viability, and Migration in Cultured Rat and Human Tendon Progenitor Cells.

Tendon healing is slow and usually results in inferior fibrotic tissue formation. Recently, application of tendon derived stem cells (TDSCs) improved tendon healing in animal studies. In a chicken model, local injection of antioxidants reduced tendon adhesion after tendon injury.

Muscle-Secreted Factors Improve Anterior Cruciate Ligament Graft Healing: An In Vitro and In Vivo Analysis.

One of the ligaments most often damaged during sports-the anterior cruciate ligament (ACL)-has poor healing capacity. On damage, reconstructive surgery is performed to restore the mechanical stability of the knee and to reduce the inflammatory milieu otherwise present in the joint. A return to normal activities, however, takes between 9 and 12 months.

Local administration of Trolox, a vitamin E analog, reduced tendon adhesion in a chicken model of flexor digitorum profundus tendon injury.

Background: Hand flexor tendon injuries are compromised with tendon adhesion. Tendon adhesion forms between flexor tendon and tendon sheath, reduces the range of motion of fingers, and affects their function. Oxidative stress is increased in flexor tendon after injury and might play a role in tendon adhesion formation.

Motion Task Selection for Kinematic Evaluation After Anterior Cruciate Ligament Reconstruction: A Systematic Review.

Purpose: To examine the different motion tasks and the protocols used to objectively quantify dynamic stability in terms of knee kinematics at different stages of anterior cruciate ligament reconstruction (ACLR) recovery.

Methods: A systematic search was done using OVID in Embase, Cochrane Central Register of Controlled Trials, Medline, PsychINFO, and AMED. A combination of the following keywords and their variations were used: anterior cruciate ligament, motion tasks (e.

Isolation and characterization of multipotent rat tendon-derived stem cells.

Stem cells have recently been isolated from humans and mice but not from rat tendon tissue. This study reports the isolation and characterization of stem cells from rat tendon. Nucleated cells isolated from rat flexor tendon tissues after collagenase digestion were plated at a low cell density to allow the selective proliferation of tendon-derived stem cells.

Sustained expression of proteoglycans and collagen type III/type I ratio in a calcified tendinopathy model.

Objectives: Alteration in the composition of extracellular matrix has been suggested as the major factor for the development of tendinopathy and calcified tendinopathy, which has poorer clinical manifestation. This study investigated the changes of major proteoglycans and collagens in a calcified tendinopathy model and correlated the expression with the acquisition of chondrocyte phenotype, ectopic ossification and loss of matrix organization in the same model.

Methods: Thirty-six rats were used.

The effect of glucocorticoids on tendon cell viability in human tendon explants.

Background And Purpose: Previous studies on the culture of human tenocytes have shown that dexamethasone and triamcinolone reduce cell viability, suppress cell proliferation, and reduce collagen synthesis. However, such cell cultures lack the extracellular matrix and three-dimensional structure of normal tendons, which affects their response to stimuli. We established a human tendon explant culture system and tested the effects of dexamethasone and triamcinolone on cell viability.

Increased apoptosis at the late stage of tendon healing.

The mechanism for the clearance of excess healing fibroblasts at the end of tendon healing has not been reported despite the importance of maintaining tissue homeostasis. This study investigated the role of apoptosis in cell turnover in a rat central 1/3 patellar tendon donor site injury model. At days 4, 7, 14, 28, months 2 and 6, the rats were killed.

Bone morphogenetic protein 13 stimulates cell proliferation and production of collagen in human patellar tendon fibroblasts.

Background: Recombinant human (rh) bone morphogenetic protein 13 (BMP13) has been shown to induce the formation of tendon and ligament tissues in animal experiments. The role of BMP13 in tissue regeneration in human tendons remains unexplored, however.

Material And Methods: We collected healthy human patellar tendon samples for histological examination and tendon fibroblast culture.

Triamcinolone suppresses human tenocyte cellular activity and collagen synthesis.

Glucocorticoid injection is widely used in tendon disorders. Despite previous studies on the histologic and biomechanical changes in tendons after glucocorticoid injections, the role of glucocorticoid in tendon rupture still is controversial. It was hypothesized that glucocorticoid has a direct deleterious effect on human tenocytes, suppressing its cellular activity and collagen production.

Regular moderate exercise training prevents decrease of CD4+ T-lymphocytes induced by a single bout of strenuous exercise in mice.

The biphasic effects of exercise training on the immune system have been studied extensively and represented by the well-known J-shaped curve with respect to training intensity. However, the relationship and interactions between "beneficial" exercise training and "harmful" strenuous exercise have not been researched. This study was designed to determine whether regular moderate exercise training could affect the changes of percentage of T-lymphocytes induced by a single bout of strenuous exercise.

The roles of bone morphogenetic protein (BMP) 12 in stimulating the proliferation and matrix production of human patellar tendon fibroblasts.

Recombinant human (rh) bone morphogenetic protein 12 (BMP12) is proved to induce the formation of tendon and ligament tissues in animal experiments. But the roles of BMP12 on tissue regeneration in human tendons remain unexplored. In the present study, healthy human patellar tendon samples were collected for histological examination and preparation of tendon fibroblast culture.

Increased expression of matrix metalloproteinase 1 (MMP1) in 11 patients with patellar tendinosis.

We studied the expression of procollagen type I, matrix metalloproteinase 1 (MMP1) and tissue inhibitor of metalloproteinase 1 (TIMP-1) by immunohistochemistry in human patellar tendinosis tissues and healthy patellar tendons. In situ gelatin zymography was used to detect collagenolytic activities. The productions of MMP1, TIMP1 and gelatinolytic activities were compared in cell cultures from tendinosis samples and controls.

Increased expression of transforming growth factor-beta1 in patellar tendinosis.

Patellar tendinosis is characterized by longstanding localized and activity-related pain, swelling and tenderness on palpation, and characteristic features on magnetic resonance imaging and ultrasonography and during surgical excision. Histologic examination of tendinosis tissues shows disrupted collagen matrix, increased cellularity, and increased proteoglycan stainability, but lack of inflammatory cell infiltration despite the clinical signs resembling inflammation. Disturbances in inflammatory response may be associated with the development of tendinosis.