The efficacy and safety of polydeoxyribonucleotide for the treatment of knee osteoarthritis: Systematic review and meta-analysis of randomized controlled trials

Polydeoxyribonucleotide ameliorates IL-1β-induced impairment of chondrogenic differentiation in human bone marrow-derived mesenchymal stem cells

Osteoarthritis (OA) is a degenerative disease of the joints, prevalent worldwide. Polydeoxyribonucleotide (PDRN) is used for treating knee OA. However, the role of PDRN in IL-1β-induced inflammatory responses in human bone marrow-derived mesenchymal stem cells (hBMSCs) remains unknown. Here, we investigated the role of PDRN in IL-1β-induced impairment of chondrogenic differentiation in hBMSCs. hBMSCs treated with PDRN showed a large micromass, enhanced safranin O and alcian blue staining intensity, and increased expression of chondrogenic genes in IL-1β-induced inflammatory responses, in addition to regulation of catabolic and anabolic genes. In addition, PDRN treatment suppressed the expression of inflammatory cytokines and mitigated IL-1β-induced apoptosis in hBMSCs. Mechanistically, PDRN treatment increased the formation of cyclic adenosine monophosphate (cAMP) and upregulated the phosphorylation of cAMP-dependent protein kinase A (PKA)/cAMP response element binding protein (CREB) through the adenosine A2A receptor in hBMSCs and thus blocked the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathway. Thus, IL-1β-induced expression of inflammatory cytokines in hBMSCs was directly reduced by adenosine A2A receptor activation. Based on our results, we suggest that PDRN may be a promising MSC-based therapeutic agent for OA.

Anti-inflammatory effects of polydeoxyribonucleotide and adipose tissue-derived mesenchymal stem cells in a canine cell model of osteoarthritis

IMPORTANCE

A relatively new therapeutic agent for osteoarthritis (OA), polydeoxyribonucleotide (PDRN), shows potential in treating human OA due to its regenerative and anti-inflammatory effects. However, studies on PDRN for canine OA are limited, and no study has investigated their use with mesenchymal stem cells (MSCs) conventionally used for OA treatment.

OBJECTIVE

This study aimed to evaluate the potential of PDRN and explore its combined effect with adipose tissue-derived MSCs (AdMSCs) in treating canine OA.

METHODS

To study the impact of PDRN, canine chondrocytes, synoviocytes, and AdMSCs were exposed to various PDRN concentrations, and viability was assessed using cell counting kit-8. The OA model was created by treating chondrocytes and synoviocytes with lipopolysaccharide, followed by treatment under three different conditions: PDRN alone, AdMSCs alone, and a combination of PDRN and AdMSCs. Using real-time quantitative polymerase chain reaction, the anti-inflammatory effects and mechanisms were investigated by quantitatively assessing pro-inflammatory cytokines, collagen degradation markers, adenosine A2a receptor (ADORA2A), and nuclear factor-kappa B.

RESULTS

PDRN alone and combined with AdMSCs significantly reduced the expression of pro-inflammatory cytokines and collagen degradation markers in an OA model. PDRN promoted AdMSC proliferation and upregulated ADORA2A expression. AdMSCs exhibited comprehensive anti-inflammatory effects through paracrine effects, and both substances reduced inflammatory gene expression through different mechanisms, potentially enhancing therapeutic effects.

CONCLUSIONS AND RELEVANCE

The results indicate that PDRN is a safe and effective anti-inflammatory material that can be used independently or as an adjuvant for AdMSCs. Although additional research is necessary, this study is significant because it provides a foundation for future research at the cellular level.

Targeting Adenosine Signalling in Knee Chondropathy: The Combined Action of Polydeoxyribonucleotide and Pulsed Electromagnetic Fields: A Current Concept Review

Chondropathy of the knee is one of the most frequent degenerative cartilage pathologies with advancing age. Scientific research has, in recent years, advanced new therapies that target adenosine A2 receptors, which play a significant role in human health against many disease states by activating different protective effects against cell sufferance and damage. Among these, it has been observed that intra-articular injections of polydeoxyribonucleotides (PDRN) and Pulsed Electromagnetic Fields (PEMF) can stimulate the adenosine signal, with significant regenerative and healing effects. This review aims to depict the role and therapeutic modulation of A2A receptors in knee chondropathy. Sixty articles aimed at providing data for our study were included in this review. The present paper highlights how intra-articular injections of PDRN create beneficial effects by reducing pain and improving functional clinical scores, thanks to their anti-inflammatory action and the important healing and regenerating power of the stimulation of cell growth, production of collagen, and the extracellular matrix. PEMF therapy is a valid option in the conservative treatment of different articular pathologies, including early OA, patellofemoral pain syndrome, spontaneous osteonecrosis of the knee (SONK), and in athletes. PEMF could also be used as a supporting therapy after an arthroscopic knee procedure total knee arthroplasty to reduce the post-operative inflammatory state. The proposal of new therapeutic approaches capable of targeting the adenosine signal, such as the intra-articular injection of PDRN and the use of PEMF, has shown excellent beneficial results compared to conventional treatments. These are presented as an extra weapon in the fight against knee chondropathy.

3D-Printed Functional Hydrogel by DNA-Induced Biomineralization for Accelerated Diabetic Wound Healing

Chronic wounds in diabetic patients are challenging because their prolonged inflammation makes healing difficult, thus burdening patients, society, and health care systems. Customized dressing materials are needed to effectively treat such wounds that vary in shape and depth. The continuous development of 3D-printing technology along with artificial intelligence has increased the precision, versatility, and compatibility of various materials, thus providing the considerable potential to meet the abovementioned needs. Herein, functional 3D-printing inks comprising DNA from salmon sperm and DNA-induced biosilica inspired by marine sponges, are developed for the machine learning-based 3D-printing of wound dressings. The DNA and biomineralized silica are incorporated into hydrogel inks in a fast, facile manner. The 3D-printed wound dressing thus generates provided appropriate porosity, characterized by effective exudate and blood absorption at wound sites, and mechanical tunability indicated by good shape fidelity and printability during optimized 3D printing. Moreover, the DNA and biomineralized silica act as nanotherapeutics, enhancing the biological activity of the dressings in terms of reactive oxygen species scavenging, angiogenesis, and anti-inflammation activity, thereby accelerating acute and diabetic wound healing. These bioinspired 3D-printed hydrogels produce using a DNA-induced biomineralization strategy are an excellent functional platform for clinical applications in acute and chronic wound repair.

Defibrotide suppresses brain metastasis by activating the adenosine A2A receptors

Brain metastasis is a devastating clinical condition globally as one of the most common central nervous system malignancies. The current study aimed to assess the effect of defibrotide, an Food and Drug Administration-approved drug, against brain metastasis and the underlying molecular mechanisms. Two tumor cell lines with high brain metastasis potential, PC-9 and 231-BR, were subjected to defibrotide treatment of increasing dosage. The metastasis capacity of the tumor cells was evaluated by cell invasion and migration assays. Western blotting was employed to determine the levels of tight junction proteins in the blood-brain barrier (BBB) including Occludin, Zo-1, and Claudin-5, as well as metastasis-related proteins including CXCR4, MMP-2, and MMP-9. The in-vitro observations were further verified in nude mice, by monitoring the growth of xenograft tumors, mouse survival and brain metastasis foci following defibrotide treatment. Defibrotide inhibited proliferation, migration, invasion, and promotes lactate dehydrogenase release of brain metastatic tumor cells, elevated the levels of BBB tight junction proteins and metastasis-related proteins. Such beneficial role of defibrotide was mediated by its inhibitory action on the SDF-1/CXCR4 signaling axis both in vitro and in vivo, as CXCR4 agonist SDF1α negated the anti-tumoral effect of defibrotide on mouse xenograft tumor growth, mouse survival and brain metastasis. Defibrotide inhibits brain metastasis through activating the adenosine A2A receptors, which in turn inhibits the SDF-1/CXCR4 signaling axis. Our study hereby proposes defibrotide as a new and promising candidate drug against brain metastasis of multiple organ origins.

The efficacy of transcatheter arterial embolization for knee pain on patients with knee osteoarthritis: A case series

BACKGROUND

Knee osteoarthritis (OA) is accompanied by inflammation and angiogenesis. Modifying angiogenesis through transcatheter arterial embolization (TAE) can be a potential treatment for knee OA.

OBJECTIVE

We subjected five OA knees in three patients to TAE and report the results of our post-treatment observations.

CASE DESCRIPTION

Three patients that had experienced knee pain for a minimum of one year prior to the study, and whose pain had persisted despite conservative treatment, were included in this study. Patients more often chose conservative treatment over surgical treatment. Pain and functional scales were evaluated before, immediately, and 1 month after TAE using the Numeric Rating Scale (NRS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). TAE was performed by an experienced interventional radiologist. The average values of NRS evaluated before and after 5 TAEs were 5.2 before TAE, 3 immediately after TAE, and 3.6 after 1 month of TAE, and the average values of WOMAC were 52, 38.4, and 36.4, respectively. There were no major adverse effects.

CONCLUSION

The examined cases support the conclusion that TAE is an effective treatment for patients with knee OA. Substantial pain relief and WOMAC improvement were observed both immediately and one month after TAE.

Beneficial Effects of Polydeoxyribonucleotide (PDRN) in an In Vitro Model of Fuchs Endothelial Corneal Dystrophy

Fuchs endothelial corneal dystrophy (FECD) is a bilateral, hereditary syndrome characterized by progressive irreversible injury in the corneal endothelium; it is the most frequent cause for corneal transplantation worldwide. Oxidative stress induces the apoptosis of corneal endothelial cells (CECs), and has a crucial function in FECD pathogenesis. The stimulation of the adenosine A_2A receptor (A_2Ar) inhibits oxidative stress, reduces inflammation and modulates apoptosis. Polydeoxyribonucleotide (PDRN) is a registered drug that acts through adenosine A_2Ar. Thus, the goal of this study was to assess the effect of PDRN in an in vitro FECD model. Human Corneal Endothelial Cells (IHCE) were challenged with H₂O₂ (200 μM) alone or in combination with PDRN (100 μg/mL), PDRN plus ZM241385 (1 μM) as an A_2Ar antagonist, and CGS21680 (1 μM) as a well-known A_2Ar agonist. H₂O₂ reduced the cells’ viability and increased the expression of the pro-inflammatory markers NF-κB, IL-6, IL-1β, and TNF-α; by contrast, it decreased the expression of the anti-inflammatory IL-10. Moreover, the pro-apoptotic genes Bax, Caspase-3 and Caspase-8 were concurrently upregulated with a decrease of Bcl-2 expression. PDRN and CGS21680 reverted the negative effects of H₂O₂. Co-incubation with ZM241385 abolished the effects of PDRN, indicating that A_2Ar is involved in the mode of action of PDRN. These data suggest that PDRN defends IHCE cells against H₂O₂-induced damage, potentially as a result of its antioxidant, anti-inflammatory and antiapoptotic properties, suggesting that PDRN could be used as an FECD therapy.

Polydeoxyribonucleotide: A Promising Biological Platform to Accelerate Impaired Skin Wound Healing

The normal wound healing process is characterized by a complex, highly integrated cascade of events, requiring the interactions of many cell types, including inflammatory cells, fibroblasts, keratinocytes and endothelial cells, as well as the involvement of growth factors and enzymes. However, several diseases such as diabetes, thermal injury and ischemia could lead to an impaired wound healing process characterized by wound hypoxia, high levels of oxygen radicals, reduced angiogenesis, decreased collagen synthesis and organization. Polydeoxyribonucleotide (PDRN) has been used to improve wound healing through local and systemic administration thanks to its ability to promote cell migration and growth, angiogenesis, and to reduce inflammation on impaired wound healing models in vitro, in vivo and clinical studies. In light of all these observations, the aim of this review is to provide a full overview of PDRN applications on skin regeneration. We reviewed papers published in the last 25 years on PubMed, inserting “polydeoxyribonucleotide and wound healing” as the main search term. All data obtained proved the ability of PDRN in promoting physiological tissue repair through adenosine A_2A receptor activation and salvage pathway suggesting that PDRN has proven encouraging results in terms of healing time, wound regeneration and absence of side effects.

Targeting Adenosine Receptor by Polydeoxyribonucleotide: An Effective Therapeutic Strategy to Induce White-to-Brown Adipose Differentiation and to Curb Obesity

Obesity is a worldwide chronic metabolic disease characterized by an abnormal fat accumulation and represents one of the main risk factors for several diseases. White adipose tissue is the primary site for energy storage in the form of triglycerides, whereas brown adipose tissue does not store energy-providing lipids but rather dissipates it by producing heat. White-to-brown adipocyte trans-differentiation could represent a new target of anti-obesity strategies and result in fat reduction. Previous studies indicated that adenosine receptor activation induces trans-differentiation of white adipocytes to brown adipocytes. The aim of this study was to evaluate the effects of polydeoxyribonucleotide (PDRN), an A_2Ar receptor agonist, in an in vitro model of browning. Mouse 3T3-L1 pre-adipocytes were differentiated in mature adipocytes with specific culture media and then treated with PDRN (10 µg/mL), PDRN + ZM241385 (1 µM), CGS21680 (1 µM) and CGS + ZM241385 for 24 h. Cell viability was studied by MTT assay, and browning induction was evaluated by Oil Red O staining and by RT-qPCR to study gene expression of browning markers. PDRN, as well as CGS21680, reduced the accumulation of lipids, cell volume and lipid droplet size; increased the expression of UCP1, PRDM16 and DIO2, considered as browning markers; and reduced the expression of FASn and FABP4, considered as whitening markers. In addition, PDRN decreased leptin expression and enhanced adiponectin mRNA levels. All these effects were abrogated when PDRN was co-incubated with the A_2Ar antagonist ZM241385. In conclusion, these results suggest that PDRN is able to induce the white-to-brown adipose differentiation through A_2Ar stimulation. Since PDRN is a safe drug already available in the market for other therapeutic indications, its “anti-obesity” potential warrants investigation in a clinical scenario.

Injections in the osteoarthritic knee: a review of current treatment options

Knee osteoarthritis is a degenerative condition characterized by progressive cartilage degradation, subchondral damage, and bone remodelling. Among the approaches implemented to achieve symptomatic and functional improvements, injection treatments have gained increasing attention due to the possibility of intra-articular delivery with reduced side effects compared to systemic therapies.

In addition to well-established treatment options such as hyaluronic acid (HA), cortico-steroids (CS) and oxygen-ozone therapy, many other promising products have been employed in the last decades such as polydeoxyribonucleotide (PDRN) and biologic agents such as platelet-rich plasma (PRP) and mesenchymal stem cells (MSCs). Moreover, ultrasound-guided intra-meniscal injection and X-ray-guided subchondral injection techniques have been introduced into clinical practice.

Even when not supported by high evidence consensus, intra-articular CS and HA injections have gained precise indications for symptomatic relief and clinical improvement in OA. Biological products are strongly supported by in vitro evidence but there is still a lack of robust clinical evidence. PRP and MSCs seem to relieve OA symptoms through a regulation of the joint homeostasis, even if their capability to restore articular cartilage is still to be proved in vivo.

Due to increasing interest in the subchondral bone pathology, subchondral injections have been developed with promising results in delaying joint replacement. Nevertheless, due to their recent development and the heterogeneity of the injected products (biologic agents or calcium phosphate), this approach still lacks strong enough evidence to be fully endorsed.

Combined biological treatments, nano-molecular approaches, monoclonal antibodies and ‘personalized’ target therapies are currently under development or under investigation with the aim of expanding our armamentarium against knee OA.

Cite this article: EFORT Open Rev 2021;6:501-509. DOI: 10.1302/2058-5241.6.210026

Effect of psychological intervention care on the negative mood and hope level of elderly patients undergoing knee arthroplasty

OBJECTIVE

We explored the influence of psychological intervention care on the negative mood and hope level of elderly patients undergoing knee arthroplasty.

METHODS

A total of 98 elderly patients undergoing knee arthroplasty in our hospital were randomly divided into a control group and an observation group, each with 49 people. The control group was given routine nursing care, and the observation group was given psychological intervention care plus routine nursing care. In the study, we compared the negative mood (Emotional distress Index Scale), preoperative hope level, quality of life, Range of Motion (ROM) of the knee, score of Hospital for Special Surgery (HSS), and satisfaction in the two groups of patients.

RESULTS

Patients in the observation group had lower Xinqing index scores than the control group (P<0.001). The scores of preoperative hope level in the observation group were higher than those of the control group (P<0.001). The scores of physical function, general health, social function, emotional role, and mental health were higher in the observation group than in the control group (all P<0.01). The ROM scores of patients in the observation group were higher than those of the control group (P<0.001). The HSS scores of patients in the observation group were higher than those of the control group (P<0.001). The patients in the observation group were significantly more satisfied with the care during hospitalization than the control group.

CONCLUSION

Psychological intervention care was effective for elderly patients undergoing knee arthroplasty. It could improve patients' negative mood, hope level, quality of life, and rehabilitation effects, and is worthy of clinical promotion and application.

NLRP3 Inflammasome: A New Pharmacological Target for Reducing Testicular Damage Associated with Varicocele

Many bioactive natural compounds are being increasingly used for therapeutics and nutraceutical applications to counteract male infertility, particularly varicocele. The roles of selenium and Polydeoxyribonucleotide (PDRN) were investigated in an experimental model of varicocele, with particular regard to the role of NLRP3 inflammasome. Male rats underwent sham operation and were daily administered with vehicle, seleno-L-methionine (Se), PDRN, and with the association Se-PDRN. Another group of rats were operated for varicocele. After twenty-eight days, sham and varicocele rats were sacrificed and both testes were weighted and analyzed. All the other rats were challenged for one month with the same compounds. In varicocele animals, lower testosterone levels, testes weight, NLRP3 inflammasome, IL-1β and caspase-1 increased gene expression were demonstrated. TUNEL assay showed an increased number of apoptotic cells. Structural and ultrastructural damage to testes was also shown. PDRN alone significantly improved all considered parameters more than Se. The Se-PDRN association significantly improved all morphological parameters, significantly increased testosterone levels, and reduced NLRP3 inflammasome, caspase-1 and IL-1β expression and TUNEL-positive cell numbers. Our results suggest that NLRP3 inflammasome can be considered an interesting target in varicocele and that Se-PDRN may be a new medical approach in support to surgery.

Unicompartmental knee replacement and high tibial osteotomy for medial unicompartmental knee osteoarthritis: A comparative study protocol

BACKGROUND

Many clinical studies have been published in the literature to compare the outcomes of unicompartmental knee replacement (UKR) and high tibial osteotomy (HTO), but reached different conclusions. Therefore, the relative merits and demerits of these 2 procedures remain under debate. The purpose of the present protocol was to design a retrospective comparative study to further investigate the clinical effectiveness of HTO compared to UKR in the medial unicompartmental osteoarthritis of knee patients.

METHODS

This is an observational retrospective research, which prospectively collected the data from several surgeons in our center and utilized the above 2 methods to treat the unicompartmental osteoarthritis of knee. In our single hospital, we reviewed unicompartmental knee osteoarthritis patients treated using UKR or HTO from June 2016 to February 2018. For the HTO, its criteria included:For the UKR, its inclusion criteria containedIn our cohorts, the clinical investigations of the knee were composed of the objective parameters, which were recorded and then documented through utilizing the Function Score and Orthopedic American Knee Society Knee Score. The extra clinical findings evaluated involved operative time, postoperative requirements of blood transfusion, possible postoperative complications, as well as the range of motion.

CONCLUSION AND DISCUSSION

The results of this study will provide clinical evidence on appropriate surgical treatment for patients with medial unicompartmental knee osteoarthritis.

TRIAL REGISTRATION

This study protocol was registered in Research Registry (researchregistry6152).