Comparison on effects of platelet-rich plasma versus autologous conditioned serum on Achilles tendon healing in a rat model

Efficacy of hyaluronic acid and conditioned serum in acute rotator cuff tear repair: A rat model study

Objective: This study aimed to compare the e!ects of local hyaluronic acid (HA) and autologous conditioned serum (ACS) on the repair of acute rotator cu! (RC) tears and their impact on functional outcomes, specifically on running performance. Methods: In this study, 25 male Wistar Albino rats, aged 16 weeks and weighing 350-400 g, were used. The rats were divided into 4 groups (n = 6 per group). Group A was the sham group, and the 3 treatment groups were as follows: group B (primary repair), group C (primary repair + ACS), and group D (primary repair + HA). A standardized procedure was used to create an acute tear-and-repair model of the RC in each treatment group. The rats in group B received no injections. Group C received ACS 24, 48, and 72 h after surgery. Patients in group D received a single dose of HA at the operative site. After a 4-week follow-up period, the rats were subjected to an exercise protocol using a computer-monitored motorized treadmill. For each treadmill run, shocks were recorded as one penalty point using a computer (one point per shock). Subsequently, the rats were sacrificed and bone-tendon healing in each group was assessed histopathologically. Results: Group A had the lowest penalty points in the final run and the highest penalty points. The best performance among the surgical groups was observed in group D. Groups C and D received fewer penalty points than group B. Group D received fewer penalty points than group C; however, there was no significant di!erence between them in pairwise comparisons (P = .132). When the statistical analysis of histological parameters was conducted, excluding the sham group, the least inflammation was observed in group D. Pairwise analysis between groups D and B revealed significantly fewer inflammatory cells in group D (P = .026). After pairwise analysis between groups, no significant di!erences were found in terms of fibroblastic proliferation, neovascularization, or fibrosis. Conclusion: This study has shown that HA application in an acute RC tear repair model significantly reduced inflammation, acceler- ated tendon healing, and markedly improved running performance by reducing pain. Additionally, immunohistochemical evaluations revealed that following HA application, collagen fibers were reorganized, forming a regular and tight connective tissue structure.

Effect of Application of Autologous Conditioned Serum on Wound Healing in Diabetic Mice Through Inhibition of STING Pathway Activation

Slow wound healing in diabetic patients is a common complication of diabetes. Autologous conditioned serum (ACS) therapy is an emerging and safe biological therapy, and may accelerate the wound healing in diabetes. To investigate the effect of ACS in promoting wound healing in diabetic mice and its possible mechanism. Twenty-four six-week-old male C57BL/6 J mice were selected and divided into 5 groups, including control group (Ctrl), diabetic wound group (DW), ACS treatment group (DW+ACS) and STING pathway validation group (DW+ACS+DMXAA), with six mice in each group. Intervention was initiated after the back incision was performed, and wound healing was assessed on day 0, day 7, and day 14, and wound healing was assessed by hematoxylin and eosin (HE) staining of skin tissue on day 14. At the same time, the wound healing of the fibroblast markers collagen I and α-SMA was measured by immunohistochemistry and western blot. ACS treatment significantly accelerated the diabetic wound according to the wound area and HE staining results. Meanwhile, collagen I and α-SMA concentration evaluated by immunohistochemistry and western blot were remarkably elevated under the ACS interference. The STING signaling pathway was obviously activated in diabetic wound tissues. After the addition of DMXAA, an agonist of STING, the healing function of ACS was dramatically reversed. The application of ACS promotes wound healing in diabetic mice by enhancing fibroblasts. Meanwhile, the STING signaling pathway was inactivated by ACS interference. Hence, ACS can be used in the treatment of wound healing of Diabetes.

Early activity after strong sutures helps to tendon healing in a rat tendon rupture model

The purpose of this study was to investigate the effect of different times return to activity on tendon healing after Double Kessler method suture in rats with Achilles tendon rupture. The left Achilles tendon of 80 10-week-old rats was repaired. The rats were randomly divided into 4 groups: non-fixed group, fixed one week group, fixed two weeks group and fixed three weeks group. In the fourth week, all rats were trained on a treadmill for one hour a day at a speed of 10 m/min. Complications were recorded during the study period and passive ankle motion was measured after the rats were euthanized. The healing and adhesion of tendons were evaluated by anatomy, biomechanics, histology and immunohistochemistry. The earlier return to activity after surgery, the higher the quality of tendon healing and the less adhesion will occur. There was no difference in complication rate among the four groups (P< 0.05). There was one case of tendon re-rupture in the non-fixed group and one case in the fixed one week group. The passive range of motion, biomechanical properties, histological evaluation and immunohistochemical results of the ankle in non-fixed group were better than those in the other three groups, while those in fixed three weeks group were worse than those in the other three groups (P< 0.05). The passive ankle range of motion, count of fibroblasts, biomechanical results, and immunohistochemical results showed no statistic significant difference between the fixed one week group and fixed two weeks group (P> 0.05). Early return to activity with strong sutures is advantageous for tendon injuries. With the advanced of return to activity time, the healing strength of tendon increased and the degree of adhesion decreased four weeks after surgery.

The effects of zinc sulfate mineral supplementation on Achilles tendon healing in rats

BACKGROUND

The Achilles tendon is the most commonly injured and ruptured tendon in the body and typically occurs during participation in sports or recreational activities in men between 30 and 50 years of age. Treatment options for Achilles tendon rupture include conservative and surgical approaches. Conservative treatment is associated with a higher risk of rerupture, while surgical treatment carries a risk of wound site complications. Generally, both methods result in a prolonged tendon healing time. Studies are ongoing to identify biomolecules that aid tendon repair. The main objective of our study is to investigate the effects of zinc sulfate (ZnSO4) mineral supplementation on Achilles tendon healing in rats.

METHODS

Forty-eight female Sprague-Dawley rats were divided into four equal groups (C-15, C-30, ZnSO4-15, and ZnSO4-30) after standard Achilles tendon repair surgery. The ZnSO4-15 and ZnSO4-30 groups received an oral zinc sulfate monohydrate solution (50 mg/kg/day) for 15 and 30 days, respectively. The C-15 and C-30 groups were given 1 mL of distilled water per day orally during the experimental periods. Rats were sacrificed on the 15th and 30th day depending on their groups, and the healing of the operated tendons was evaluated using Movin and Bonar histopathologic scoring. For biomechanical analyses, the operated and intact Achilles tendons of all groups were removed, and tensile tests were performed to determine the tensile strength and toughness values for each tendon.

RESULTS

Movin and Bonar scores were significantly lower in the ZnSO4-15 group than in the C-15 group and in the ZnSO4-30 group than in the C-30 group (p<0.05). Although we did not find the biomechanical results statistically significant, the intact tendons of the ZnSO4-15 group exhibited higher toughness than those of the C-15 group, and the tensile strength and toughness values of the operated and intact tendons of the ZnSO4-30 group were also higher than those of the C-30 group.

CONCLUSION

Zinc sulfate monohydrate mineral supplementation had histopathologically positive effects on the proliferation and remodeling stages of Achilles tendon healing and may biomechanically benefit both operated and intact tendons.

Equine Musculoskeletal Pathologies: Clinical Approaches and Therapeutical Perspectives-A Review

Musculoskeletal injuries such as equine osteoarthritis, osteoarticular defects, tendonitis/desmitis, and muscular disorders are prevalent among sport horses, with a fair prognosis for returning to exercise or previous performance levels. The field of equine medicine has witnessed rapid and fruitful development, resulting in a diverse range of therapeutic options for musculoskeletal problems. Staying abreast of these advancements can be challenging, prompting the need for a comprehensive review of commonly used and recent treatments. The aim is to compile current therapeutic options for managing these injuries, spanning from simple to complex physiotherapy techniques, conservative treatments including steroidal and non-steroidal anti-inflammatory drugs, hyaluronic acid, polysulfated glycosaminoglycans, pentosan polysulfate, and polyacrylamides, to promising regenerative therapies such as hemoderivatives and stem cell-based therapies. Each therapeutic modality is scrutinized for its benefits, limitations, and potential synergistic actions to facilitate their most effective application for the intended healing/regeneration of the injured tissue/organ and subsequent patient recovery. While stem cell-based therapies have emerged as particularly promising for equine musculoskeletal injuries, a multidisciplinary approach is underscored throughout the discussion, emphasizing the importance of considering various therapeutic modalities in tandem.

The effects of orthobiologics in the treatment of tendon pathologies: a systematic review of preclinical evidence

Purpose

The aim of this systematic review is to explore the current available knowledge about tendon disorders and orthobiologics derived by preclinical experiments to evaluate their role and efficacy in the different stages and conditions related to the tendon healing processes.

Methods

The systematic review was performed according to the PRISMA guidelines. Different electronic databases (MEDLINE, Web of Science, EMBASE) were searched for studies investigating orthobiologics (PRP and cell-based products from adipose tissue or bone marrow) in animal models or veterinary clinical trials for tendon pathologies (complete/partial tendon ruptures, rotator cuff tears, tendinopathy, enthesis-related injuries). Data regarding the specific product used, the treatment site/pathology, the host and the model were collected. The results were classified into the following categories: histological, biomechanical, molecular and imaging.

Results

A large pool of preclinical studies on tendon disorders have been found on platelet-rich plasma (PRP), while data about stromal vascular fraction (SVF) and bone marrow concentrate (BMAC) are still limited and frequently focused on expanded cells, rather than orthobiologics prepared at the point of care.

The effect of PRP is related to an acceleration of the healing process, without improvements in the final structure and properties of repaired tendon. Cell-based products have been reported to produce more durable results, but the level of evidence is currently insufficient to draw clear indications.

Conclusions

The preclinical results about orthobiologics applications to tendon pathologies would support the rationale of their clinical use and encourage the performance of clinical trials aimed to confirm these data in human subjects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-022-00468-w.

The Functions and Mechanisms of Low-Level Laser Therapy in Tendon Repair (Review)

Tendon injury is a common disease of the musculoskeletal system, accounting for roughly 30%–40% of sports system disorder injuries. In recent years, its incidence is increasing. Many studies have shown that low-level laser therapy (LLLT) has a significant effect on tendon repair by firstly activating cytochrome C oxidase and thus carrying out the photon absorption process, secondly acting in all the three phases of tendon repair, and finally improving tendon recovery. The repair mechanisms of LLLT are different in the three phases of tendon repair. In the inflammatory phase, LLLT mainly activates a large number of VEGF and promotes angiogenesis under hypoxia. During the proliferation phase, LLLT increases the amount of collagen type III by promoting the proliferation of fibroblasts. Throughout the remodeling phase, LLLT mainly activates M2 macrophages and downregulates inflammatory factors, thus reducing inflammatory responses. However, it should also be noted that in the final phase of tendon repair, the use of LLLT causes excessive upregulation of some growth factors, which will lead to tendon fibrosis. In summary, we need to further investigate the functions and mechanisms of LLLT in the treatment of tendon injury and to clarify the nature of LLLT for the treatment of diverse tendon injury diseases.

Effectiveness of intra-articular autologous-conditioned serum injection in knee osteoarthritis: a meta-analysis study

Aim

Knee osteoarthritis is a common disabling disorder, with no curative treatment. This study aims to assess autologous conditioned serum effectiveness in its treatment.

Materials & methods

Following a systematic search (2000-2020) on major databases and screening and filtering processes, eight articles were included in the final analyses. The pooled effect of visual analog scale (VAS) and the Western Ontario and McMaster Universities (WOMAC) variables was evaluated before and after the intervention.

Results

The combined standardized mean difference for the global WOMAC score was -2.44 and the combined weighted mean difference was -22.92. The combined standardized mean difference for the VAS score was -3.77 and the combined weighted mean difference was -32.37 (p < 0.000).

Conclusion

This meta-analysis reported that the autologous conditioned serum can reduce pain and improve function (VAS and WOMAC outcome measures) in patients with knee osteoarthritis.

Autologous conditioned serum for degenerative diseases and prospects

Autologous conditioned serum (ACS) is a blood-derived product that is prepared by the incubation of whole blood with medical-grade glass beads, resulting in serum enrichment in interleukin-1 receptor antagonist (IL-1Ra), anti-inflammatory cytokines (IL-4, IL-10, and IL-13), and high concentrations of growth factors. ACS has shown qualitatively and quantitatively better therapeutic effects than most established pharmacological treatments and surgery for joint diseases given its ability to both target the inflammatory cascade to decrease cartilage destruction as well as improve endogenous repair mechanisms. ACS application is simple and safe with limited adverse effects. This article reviews the role of ACS in degenerative joint disease, in addition to other inflammatory and autoimmune diseases, given its regenerative and immune-modulating properties.