Adenosine A2A Receptor Agonist, Polydeoxyribonucleotide Treatment Improves Locomotor Function and Thermal Hyperalgesia Following Neuropathic Pain in Rats

PURPOSE

Lithotomy position has been widely used in the various urologic surgery. Occasionally sensory and motor problems of the lower extremities are occurred due to the lithotomy position and these deficits may be related with sciatic nerve injury (SNI). Inflammatory process is a factor to induce functional impairment after SNI. Therefore, we evaluated the role of adenosine A2A receptor agonists, polydeoxyribonucleotide (PDRN) showing anti-inflammatory effect on locomotor function following SNI in rats.

METHODS

Sciatic nerve was compressed with surgical clips for 1 minute after exposing of right sciatic nerve. After 3 days of SNI, PDRN (2, 4, and 8 mg/kg) was applied to the damaged area of sciatic nerve once daily for 10 days. Walking track analysis was conducted for locomotor function and plantar test was performed for thermal pain sensitivity. Level of cyclic adenosine-3´,5´-monophosphate (cAMP) were measured using enzyme-linked immunosorbent assay. Western blot analysis was performed for tumor necrosis factor (TNF)-α, interleukin (IL)-1β, cAMP response element binding protein (CREP), vascular endothelial growth factor (VEGF). Immunofluorescence for neurofilament was also conducted.

RESULTS

Locomotor function was decreased and thermal pain sensitivity was increased by SNI. SNI enhanced proinflammatory cytokines' production, such as TNF-α and IL-1β, while suppressed CREP phosphorylation and cAMP level. SNI also reduced the expression of VEGF and neurofilaments. However, treatment with PDRN inhibited proinflammatory cytokines' production and upregulated CREP phosphorylation and cAMP expression. PDRN also enhanced the expression of VEGF and neurofilaments. As a result, PDRN improved locomotor function and alleviated thermal hyperalgesia after SNI.

CONCLUSION

PDRN has shown potential to be used as an effective treatment for neuropathic pain.

Effect of polydeoxyribonucleotide with xenogeneic collagen matrix on gingival phenotype modification: a pilot preclinical study

PURPOSE

To investigate the effect of xenogeneic collagen matrix (XCM) with polydeoxyribonucleotide (PDRN) for gingival phenotype modification compared to autogenous connective tissue graft.

METHODS

Five mongrel dogs were used in this study. Box-type gingival defects were surgically created bilaterally on the maxillary canines 8 weeks before gingival augmentation. A coronally positioned flap was performed with either a subepithelial connective tissue graft (SCTG) or XCM with PDRN (2.0 mg/mL). The animals were sacrificed after 12 weeks. Intraoral scanning was performed for soft tissue analysis, and histologic and histomorphometric analyses were performed.

RESULTS

One animal exhibited wound dehiscence, leaving 4 for analysis. Superimposition of STL files revealed no significant difference in the amount of gingival thickness increase (ranging from 0.69±0.25 mm to 0.80±0.31 mm in group SCTG and from 0.48±0.25 mm to 0.85±0.44 mm in group PDRN; P>0.05). Histomorphometric analysis showed no significant differences between the groups in supracrestal gingival tissue height, keratinized tissue height, tissue thickness, and rete peg density (P>0.05).

CONCLUSIONS

XCM soaked with PDRN yielded comparable gingival augmentation to SCTG.

Multimodal therapy strategy based on a bioactive hydrogel for repair of spinal cord injury

Traumatic spinal cord injury results in permanent and serious neurological impairment, but there is no effective treatment yet. Tissue engineering approaches offer great potential for the treatment of SCI, but spinal cord complexity poses great challenges. In this study, the composite scaffold consists of a hyaluronic acid-based hydrogel, decellularized brain matrix (DBM), and bioactive compounds such as polydeoxyribonucleotide (PDRN), tumor necrosis factor-α/interferon-γ primed mesenchymal stem cell-derived extracellular vesicles (TI-EVs), and human embryonic stem cell-derived neural progenitor cells (NPC). The composite scaffold showed significant effects on regenerative prosses including angiogenesis, anti-inflammation, anti-apoptosis, and neural differentiation. In addition, the composite scaffold (DBM/PDRN/TI-EV/NPC@Gel) induced an effective spinal cord regeneration in a rat spinal cord transection model. Therefore, this multimodal approach using an integrated bioactive scaffold coupled with biochemical cues from PDRN and TI-EVs could be used as an advanced tissue engineering platform for spinal cord regeneration.

The impact of polydeoxyribonucleotide on early bone formation in lateral-window sinus floor elevation with simultaneous implant placement

PURPOSE

The aim of this study was to evaluate the impact of polydeoxyribonucleotide (PDRN) on histologic outcomes when implant placement and lateral sinus floor elevation are performed simultaneously.

METHODS

Three bimaxillary premolars (P2, P3, and P4) were extracted from 4 beagle dogs 2 months before lateral sinus floor elevation. After lateral elevation of the sinus membrane, each sinus was allocated to either the test or control group. Sinuses underwent either 1) collagenated synthetic bone graft with PDRN following lateral sinus floor elevation (test group) or 2) collagenated synthetic bone graft without PDRN after lateral sinus floor elevation (control group). Eight weeks after the surgical procedure, all animals were euthanised for a histologic and histomorphometric assessment. Augmented height (AH), protruding height (PH), and bone-to-implant contact in pristine (BIC_p) and augmented (BIC_a) bone were measured. The composition of the augmented area, which was divided into 3 areas of interest located in coronal, middle and apical areas (AOI_C, AOI_M, and AOI_A), was calculated with 3 parameters: the area percentage of new bone (pNB), residual bone graft particle (pRBP), and fibrovascular connective tissue (pFVT).

RESULTS

AH, PH, BIC_p, BIC_a total, BIC_a coronal, and BIC_a middle values were not significantly different between sinuses in the control and test groups (all P>0.05). The BIC_a apical of sinuses in the test group (76.7%±9.3%) showed statistically higher values than those of sinuses in the control group (55.6%±22.1%) (P=0.038). pNB, pRBP, and pFVT showed statistically significant differences between the 2 groups in AOI_A (P=0.038, P=0.028, and P=0.007, respectively). pNB, pRBP, and pFVT in AOI_C and AOI_M were not significantly different between samples in the control and test groups (all P>0.05).

CONCLUSIONS

The histologic findings revealed that lateral sinus floor elevation with PDRN might improve early new bone formation and enable higher bone-to-implant contact.

Polydeoxyribonucleotide ameliorates alcoholic liver injury though suppressing phosphatidylinositol 3-kinase/protein kinase B signaling pathway in mice

Polydeoxyribonucleotide (PDRN), which is adenosine A_2A receptor agonist, facilitates healing and inhibits inflammation and apoptosis. The effect of PDRN on alcoholic liver injury (ALI) was evaluated focusing on the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. The mice were given daily oral administration of 50% ethanol at a dose of 4 g/kg during 8 weeks. After 4 weeks of alcohol intake, 200 μL of normal saline containing 8-mg/kg PDRN was intraperitoneally administered 3 times a week for 4 weeks. To determine whether the action of PDRN occurs through the adenosine A_2A receptor, 8-mg/kg 3,7-dimethyl-1-propargylxanthine (DMPX) with PDRN was treated. The concentration of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was detected. For liver histopathological score, hematoxylin and eosin staining was conducted. Enzyme-linked immunoassay was used to measure cyclic adenosine-3',5'-monophosphate (cAMP) concentration. PI3K and Akt expression was determined using Western blot analysis. In the results, PDRN treatment suppressed AST and ALT level in serum and liver tissue, and improved damaged liver tissue and decreased histological score. PDRN application inhibited the expression of phosphorylated PI3K/Akt signaling pathway. The increasing effect of PDRN on cAMP level ats as a mechanism for ALI treatment. Co-treatment of DMPX with PDRN did not reduce apoptosis, causing no improvement in liver function. As a result of this experiment, PDRN has the potential to be selected as a therapeutic agent for ALI.

Comparison of the effectiveness of extensor muscle strengthening exercise by itself, exercise with polydeoxyribonucleotide injection, and exercise with extracorporeal shockwave therapy in lateral epicondylitis: a randomized controlled trial

Background

Extensor muscle strengthening exercises with counterforce braces (EX) is a conventional conservative treatment for lateral epicondylitis (LE) of the elbow. In addition, polydeoxyribonucleotide (PDRN) or extracorporeal shockwave therapy (ESWT) has been recently used for LE.

Methods

Sixty-three patients with chronic LE participated in this study and randomly allocated in three groups (G1: EX, G2: EX+PDRN injection, and G3: EX+ESWT). All of the three groups were taught to perform EX at the first out-patient department (OPD) visit. Group 2 was injected with 3 mL PDRN (5.625 mg/3 mL), while group 3 received ESWT at the first OPD visit. Visual analog scale pain score, Mayo elbow performance score (MEPS), and ultrasonographic examination were checked before, 6 weeks, and 12 weeks after the treatments.

Results

Overall functional scores and ultrasonographic findings in all three groups improved after treatment. The mean MEPS in group 2 improved more than groups 1 and 3 at 6 weeks (G1, 56.9>62.4; G2, 54.3>65.0; G3, 55.7>62.6), and more than group 1 at 12 weeks (G1, 56.9>67.9; G2, 54.3>73.6). The mean common extensor tendon depth (CETD) on ultrasonography in group 2 increased more than groups 1 and 3 at 6 and 12 weeks (6 weeks: G1, 0.385>0.386; G2, 0.332>0.392; G3, 0.334>0.357; 12 weeks: G1, 0.385>0.409; G2, 0.332>0.438; G3, 0.334>0.405 [cm]).

Conclusions

PDRN injections combined with EX exhibited a greater improvement in mean MEPS and mean CETD compared to EX only or EX combined with ESWT for LE within the 12 weeks follow-up.

Polydeoxyribonucleotide and Polynucleotide Improve Tendon Healing and Decrease Fatty Degeneration in a Rat Cuff Repair Model

BACKGROUND

After surgical repair of chronic rotator cuff tears, healing of the repaired tendons often fails and is accompanied by high-level fatty degeneration. Our purpose was to explore the effects of polydeoxyribonucleotide (PDRN) and polynucleotide (PN) on tendon healing and the reversal of fatty degeneration in a chronic rotator cuff tear model using a rat infraspinatus.

METHODS

Sixty rats were randomly assigned to the following three groups (20 rats per group: 12 for histological evaluation and 8 for mechanical testing): saline + repair (SR), PDRN + repair (PR), and PN + repair (PNR). The right shoulder was used for experimental intervention, and the left served as a control. Four weeks after detaching the infraspinatus, the torn tendon was repaired. Saline, PDRN, and PN were applied to the repair sites. Histological evaluation was performed 3 and 6 weeks after repair and biomechanical analysis was performed at 6 weeks.

RESULTS

Three weeks after repair, the PR and PNR groups had more CD168-stained cells than the SR group. The PR group showed a larger cross-sectional area (CSA) of muscle fibers than the SR and PNR groups. Six weeks after repair, the PR and PNR groups showed more adipose cells, less CD68-stained cells, and more parallel tendon collagen fibers than the SR group. The PR group had more CD 68-stained cells than the PNR group. The PR group showed a larger CSA than the SR group. The mean load-to-failure values of the PR and PNR groups were higher than that of the SR group, although these differences were not significant.

CONCLUSION

PDRN and PN may improve tendon healing and decrease fatty degeneration after cuff repair.

Polydeoxyribonucleotide Attenuates Airway Inflammation Through A2AR Signaling Pathway in PM10-Exposed Mice

Purpose

Inhalation of air containing high amounts of particular matter (PM) causes various respiratory disorders including asthma, chronic obstructive pulmonary disease, and lung cancer. The changes of expression of inflammatory factors by polydeoxyribonucleotide (PDRN) administration in the PM₁₀-exposed trachea inflammation model were evaluated.

Methods

PM₁₀ was administered to mouse trachea to induce acute inflammatory damage, and changes in inflammatory factors were observed after administration of PDRN and 3,7-dimethyl-1-propargylxanthine (DMPX) for 3 days daily. Expression of inflammatory cytokines, adenosine A_2A receptor (A_2AR), protein kinase A (PKA), 3΄,5΄-cyclic adenosine monophosphate responsive element binding protein (CREB) were detected by enzyme‐linked immunosorbent assay, immunofluorescence, and western blot assay.

Results

PM-exposed trachea showed increased tumor necrosis factor (TNF)-α and interleukin (IL)-1β expression, and expression of TNF-α and IL-1β was inhibited by PDRN treatment in PM-exposed mice. PM-exposed trachea showed increased nuclear factor (NF)-κB phosphorylation, and phosphorylation of nuclear factor-kappa B was inhibited by PDRN treatment in PM-exposed mice. PM-exposed trachea showed increased expression of A_2AR, but PDRN treatment more enhanced A_2AR expression in PM-exposed mice. PKA phosphorylation was not changed and CREP phosphorylation was decreased, however PDRN treatment increased phosphorylation of PKA and CREB in PM-exposed mice. DMPX treatment blocked all the effects of PDRN on PM-exposed mice, demonstrating that the action of PDRN occurs via A_2AR.

Conclusions

PDRN treatment attenuated inflammation in the trachea of the PM₁₀-exposed mice. This improving effect of PDRN can be ascribed to the activation of A_2AR through the cAMP-PKA pathway.

PDRN, a natural bioactive compound, blunts inflammation and positively reprograms healing genes in an "in vitro" model of oral mucositis

Oral mucositis is a side effect hard to treat following high dose chemotherapy or radiotherapy. Adenosine A_2A receptor stimulation blocks NF-κB and boosts the Wnt/β-catenin signaling, thus blunting inflammation and triggering growth factor codifying genes. Polydeoxyribonucleotide (PDRN) is a registered drug that activates the A_2A receptor. Therefore, the aim of this study was to evaluate PDRN effects in an "in vitro" model of oral mucositis induced by prompting an inflammatory phenotype in human gingival fibroblasts (GF) and human oral mucosal epithelial cells (EC). GF and EC were stimulated with LPS (2 μg/ml) alone or in combination with i) PDRN (100 μg/ml); ii) PDRN plus ZM241385 (1 μM) as an A_2AR antagonist; iii) CGS21680 (1 μM) as an A_2AR agonist. LPS boosted NF-κB, TNF-α and IL-6 expression, decreased IL-10 levels and downregulated both Wnt/β-catenin, VEGF and EGF expression. PDRN reverted the LPS-induced phenotype as well as CGS21680. Co-incubation with ZM241385 abolished PDRN effects, thus confirming A_2A receptor involvement in PDRN mechanism of action. These results suggest that PDRN efficacy may be due to a "dual mode" of action: NF-κB inhibition and Wnt/β-catenin signaling activation. However, these interesting findings need to be confirmed by animal and clinical studies.

Polydeoxyribonucleotide Ameliorates Inflammation and Apoptosis in Achilles Tendon-Injury Rats

PURPOSE

Adenosine A2A receptor agonist polydeoxyribonucleotide (PDRN) possesses an anti-inflammatory effect and suppress apoptotic cell death in several disorders. In this current study, the effect of PDRN on inflammation and apoptosis in rats with Achilles tendon injury was investigated.

METHODS

von Frey filament test and plantar test were conducted for the determination of pain threshold. Analysis of histological alterations was conducted by hematoxylin and eosin staining. Immunohistochemistry for cleaved caspase-3-positive cells and cleaved caspase-9-positive cells was done. Enzyme-linked immunoassay was used to detect the concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and cyclic adenosine-3',5'-monophosphate (cAMP). Western blot was conducted to detect the protein levels of cAMP response element-binding protein (CREB), protein kinase A (PKA), Bcl-2-associated X (Bax), and B-cell lymphoma 2 (Bcl-2).

RESULTS

PDRN treatment relieved mechanical allodynia and alleviated thermal hyperalgesia after Achilles tendon injury. TNF-α and IL-6 concentrations were decreased by PDRN application. PDRN injection significantly enhanced cAMP concentration and phosphorylated CREB versus CREB ratio, showing cAMP-PKA-CREB pathway was activated by PDRN application. PDRN treatment inhibited percentages of cleaved caspase-3-positive cells and caspase-9-posiive cells and the suppressed Bax versus Bcl-2 ratio in Achilles tendon injury rats.

CONCLUSION

PDRN is probably believed to have a good effect on pain and inflammation in the urogenital organs. PDRN may be used as a new treatment for Achilles tendon injury.

Protective Effect of Polydeoxyribonucleotide Against CCl4-Induced Acute Liver Injury in Mice

Purpose

Polydeoxyribonucleotide (PDRN) is a substance known to suppress inflammation and accelerate wound healing. In this experiment, the effect of PDRN treatment on carbon tetrachloride (CCl₄)-evoked acute liver injury (ALI) was investigated using mice.

Methods

We analyzed the levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and conducted hematoxylin and eosin staining in accompany with terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining. Western blot analysis was also conducted to assess the expressions of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, adenosine A_2A receptor, Bcl-2-associated X protein (Bax), and B-cell lymphoma 2 (Bcl-2). The mice were received intraperitoneal injection of 10-mL/kg CCl₄, 4 times, once every 2 days. The mice in the PDRN treatment groups received intraperitoneal injection of 200-μL distilled water comprising each concentration of PDRN for 7 days starting 1 day after first CCl₄ injection.

Results

ALT and AST concentrations in the serum were reduced and TNF-α, IL-1β, and IL-6 expressions were decreased by PDRN injection in CCl₄-evoked ALI mice. PDRN injection suppressed Bax versus Bcl-2 ratio and reduced the percentage of TUNE-positive cells in CCl₄-evoked ALI mice. PDRN injection overexpressed adenosine A_2A receptor in CCl₄-evoked ALI mice.

Conclusions

The therapeutic efficacy of PDRN also can be expected for CCl₄-evoked acute urogenital injury in addition to ALI. The current research suggests that PDRN may be used for the therapeutic agent of CCl₄-evoked ALI.

Anti-Allodynic Effects of Polydeoxyribonucleotide in an Animal Model of Neuropathic Pain and Complex Regional Pain Syndrome

BACKGROUND

Spinal nerve ligation (SNL) model is one of the representative models of the neuropathic pain model. Neuropathic pain in a chronic post-ischemic pain (CPIP) mimics the symptoms of complex regional pain syndrome (CRPS). The administration of polydeoxyribonucleotide (PDRN), which has regenerative and anti-inflammatory effects, has been studied and is used in clinical practice treating various diseases. However, the analgesic effect of PDRN in a neuropathic pain or CRPS model remains unknown.

METHODS

PDRN (3.3, 10, and 20 mg/kg) was administered into the subcutaneous (SC) layer of the hind paws of SNL and CPIP models. Mechanical anti-allodynic effects were then investigated using the von Frey test. In the immunohistochemical examination, dorsal root ganglia (DRG) and the spinal cord were harvested and examined for the expression of glial fibrillary acidic protein (GFAP) after the 20 mg PDRN injection.

RESULTS

Mechanical allodynia was significantly alleviated by administration of PDRN in SNL and CPIP mice at all of the time point. As the dose of PDRN increased, the effect was greater. The 20 mg PDRN injection was found to have the most effective anti-allodynic effect. The increased expression of GFAP in DRG and the spinal cord of SNL and CPIP model decreased following the administration of PDRN than vehicle.

CONCLUSION

SC administration of PDRN results in the attenuation of allodynia and activation of astrocytes in neuropathic pain or CRPS models. We propose that PDRN can have significant potential advantages in neuropathic pain treatment.

Combination Therapy With Polydeoxyribonucleotide and Pirfenidone Alleviates Symptoms of Acute Respiratory Distress Syndrome in Human Lung Epithelial A549 Cells

PURPOSE

Acute respiratory distress syndrome (ARDS) is characterized by its acute onset of symptoms such as bilateral pulmonary infiltrates, severe hypoxemia, and pulmonary edema. Many patients with ARDS survive in the acute phase, but then die from significant lung fibrosis.

METHODS

The effect of combination therapy with polydeoxyribonucleotide (PDRN) and pirfenidone on ARDS was investigated using human lung epithelial A549 cells. ARDS environment was induced by treatment with lipopolysaccharide and transforming growth factor (TGF)-β. Enzyme-linked immunoassay for connective tissue growth factor (CTGF) and hydroxyproline were conducted. Western blot for collagen type I, fibroblast growth factor (FGF), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 was performed.

RESULTS

In this study, 8-μg/mL PDRN enhanced cell viability. Combination therapy with PDRN and pirfenidone and pirfenidone monotherapy suppressed expressions of CTGF and hydroxyproline and inhibited expressions of collagen type I and FGF. Combination therapy with PDRN and pirfenidone and PDRN monotherapy suppressed expression of TNF-α and IL-1β.

CONCLUSION

The combination therapy with PDRN and pirfenidone exerted stronger therapeutic effect against lipopolysaccharide and TGF-β-induced ARDS environment compared to the PDRN monotherapy or pirfenidone monotherapy. The excellent therapeutic effect of combination therapy with PDRN and pirfenidone on ARDS was shown by promoting the rapid anti-inflammatory effect and inhibiting the fibrotic processes.

Evaluating the mucoprotective effect of polydeoxyribonucleotide against indomethacin-induced gastropathy via the MAPK/NF-κB signaling pathway in rats

Non-steroidal anti-inflammatory drugs (NSAIDs) cause gastric mucosal damage and gastric ulceration. Among the most commonly used NSAIDs, indomethacin upregulates mucosal tumor necrosis factor-α, which activates nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinases (MAPK) to induce various pro-inflammatory mediators. Polydeoxyribonucleotide (PDRN) is an adenosine A_2A receptor agonist that exerts anti-inflammatory effects. In this study, we evaluated the efficacy of PDRN in the initial treatment of gastropathy against that of ecabet sodium and irsoglandin maleate, which are commonly used medications. The rats were administrated indomethacin once a day for 7 days after 24 h of fasting to induce gastropathy. Rats in the drug-treated groups were orally administrated 500 μl of distilled water containing the drug once daily for 7 days 1 h after indomethacin administration. Indomethacin administration caused mucosal damage and increased pro-inflammatory cytokine release. Both NF-κB and MAPK cascade factors were increased by indomethacin administration. PDRN therapy more potently suppressed the expressions of NF-κB and MAPK cascade factors compared to other drugs. The expression of cyclic adenosine-3',5'-monophosphate was also increased by PDRN treatment in the indomethacin-induced gastropathy rats. These changes led to a reduction in pro-inflammatory cytokines and apoptotic factors, which ultimately promote recovery of damaged gastric tissue. Therefore, PDRN may serve as a new therapeutic option in the initial treatment of NSAIDs-induced gastropathy.

Synergic regenerative effects of polydeoxyribonucleotide and microcurrent on full-thickness rotator cuff healing in a rabbit model

BACKGROUND

Rotator cuff tendon tears (RCTTs) are common adult injuries. We hypothesized that a local injection of polydeoxyribonucleotide (PDRN) and microcurrent therapy (MIC) would be more effective in regenerating a tendon tear than PDRN administration alone.

OBJECTIVES

To evaluate the effect of PDRN combined with MIC on the regeneration of RCTTs in a rabbit subscapularis tendon chronic RCTT model.

METHODS

Rabbits (n=24) were allocated to 3 groups at 6 weeks after full-thickness RCTT (FTRCTT): 0.2mL normal saline (G1-SAL); 0.2mL PDRN with Sham MIC (G2-PDRN+Sham MIC); and 0.2mL PDRN with MIC (G3-PDRN+MIC). All treatments were performed under ultrasound guidance. PDRN was injected weekly for 4 weeks and sham MIC or MIC was applied daily for 4 weeks after the first PDRN injection.

RESULTS

In the G3-PDRN+MIC group, the mean (SD) subscapularis tendon tear size was continuously reduced from 1 week post-treatment to 4 weeks and was significantly decreased as compared with the other 2 groups [6.0 (1.5) vs. G1: 11.5 (1.8) and G2: 9.1 (1.6) mm²; G3 vs. G1, P<0.001; G3 vs. G2, P=0.018]. The gross morphologic mean tendon tear size was significantly smaller in the G3-PDRN+MIC group than G1-SAL and G2-PDRN+ Sham MIC groups [8.8 (3.5) vs. 15.9 (2.3) and 12.4 (1.6) mm²; G3 vs. G1, P<0.001; G3 vs. G2, P=0.03]. Mean values for regenerated collagen type 1 fibers, angiogenesis, and walking parameters were all greater for the G3-PDRN+MIC group than the other 2 groups based on histological examination and motion analysis [collagen type 1, G3: 1.60 (0.80) vs. G1: 0.45 (0.60), G2: 1.10 (0.74), G3 vs. G1, P<0.001; G3 vs. G2, P=0.002] [angiogenesis, G3: 2.44 (0.73) vs. G1: 0.80 (0.82) and G2: 2.06 (0.81), G3 vs. G1, P<0.001; G3 vs. G2, P=0.006] [walking distance, G3: 6391.4 (196.9) vs. G1: 4852.8 (137.3) and G2: 5514.4 (257.3) cm; G3 vs. G1, P<0.001; G3 vs. G2, P<0.001].

CONCLUSIONS

On gross morphologic, histological, and motion analysis, combined PDRN with MIC therapy was more effective than PDRN alone treating a rabbit model of chronic traumatic FTRCTT.

Effects of topical polydeoxyribonucleotide on radiation-induced oral mucositis

•

Oral mucositis (OM), the most common toxicity in patients with head and neck cancer.

•

Polideoxyribonucleotide (PDRN) is highly regenerative and anti-inflammatory drug.

•

OM lesions were attenuated to Grade 2 within the first week of PDRN treatment.

•

Pain was relieved about 2–3 days after starting treatment with PDRN spray.

•

All the patients completed Radiotherapy and chemotherapy without any interruptions.

Introduction

Oral mucositis, the most common adverse effect of radiotherapy (RT) and/or chemotherapy is observed in almost 97% of patients with head and neck cancer. Although several agents like corticosteroids, lidocaine and vitamins are available for its prevention or management, results are often disappointing. Here we report on the effects of a topically applied, highly purified natural deoxyribonucleic acid from sturgeon gonads on three cases of moderate to severe oral mucositis in patients with head and neck cancer.

Case Description

Three patients who had undergone RT and/or chemotherapy received an oral spray containing sodium salt-based natural deoxyribonucleic acid (PDRN) for Grade 3 oral mucositis. Treatment continued for one month after the end of RT. No patient reported any allergic reactions. RT and chemotherapy were not interrupted and opioid therapy was not given to any patient. Pain was relieved about 2–3 days after starting treatment and oral mucositis was reduced to G2 within one week.

Conclusions

Outcomes in all 3 cases showed topical use of the sodium salt-based PDRN derived from sturgeon gonads was acceptable and safe when used topically for therapeutic and regenerative purposes.

Present results are encouraging and suggest a more in-depth study is warranted on its use in a larger patient cohort with RT-induced oral mucositis.

Polydeoxyribonucleotide injection in the patients with partial-thickness tear of supraspinatus tendon: a prospective and pilot study using ultrasound

OBJECTIVE

Polydeoxyribonucleotide as adenosine receptor (A_2A) agonist has been used in plastic surgery and dermatology related to its regenerative property. The aim of this pilot study is to evaluate the safety and efficacy of polydeoxynucleotide injection in patients with rotator cuff tears by a variety of outcomes including pain, disability, physical performance test, and ultrasonography (US).

METHODS

Seventeen patients (9 men, 8 women, age: 57.9 ± 9.1) with partial-thickness tear of supraspinatus tendon were evaluated in a prospective, open-label, and pre-and-post study. Seventeen patients underwent 3 times intra-lesional polydeoxynucleotide injection under ultrasound (US) guidance on weeks 0, 2 and 4. The safety and efficacy were assessed on weeks 0, 6 and 12. Main outcome measures included shoulder pain on Visual Analogue Scale (VAS) and DASH (disabilities of arm, hand, shoulder) score, range of motion in shoulder, shoulder strength and tear volume (cm³) by US. Adverse events were monitored. (CRIS: https://www.cris.nih.go.kr , KCT0000767).

RESULTS

Active shoulder pain on VAS reduced from 5.53 to 3.53 (P = 0.016), and acting pain, one of DASH questionnaires, reduced from 3.35 to 2.00 (P < 0.001). However, resting shoulder pain on VAS and total DASH scores were not significantly different. Forward flexion and internal rotation in range of motion improved significantly (from 169.41 to 178.13 degrees [P = 0.004] and from 83.53 to 88.75 degrees [P = 0.014], respectively). The volume of torn lesion decreased during the study period, however it was not significant. There were no significant adverse events leading to hospitalization.

CONCLUSIONS

Minimally invasive procedure through polydeoxynucleotide injection into torn area of supraspinatus tendon on US could be candidate for the safe and effective treatment on shoulder pain and limited range of motion in patients with rotator cuff tear.

Combination therapy with polydeoxyribonucleotide and proton pump inhibitor enhances therapeutic effectiveness for gastric ulcer in rats

AIMS

The main action of proton pump inhibitors (PPIs) is to inhibit gastric acid secretion, and PPIs are widely used to treat gastric ulcer (GU). However, if the action of promoting gastric mucosal regeneration is added, the effectiveness of GU treatment can be enhanced. Thus, in order to improve the therapeutic effect on GU, we tried to develop combination therapy promoting regeneration in injured tissue besides suppressing gastric acid secretion.

MAIN METHODS

Polydeoxyribonucleotide (PDRN) was selected to evaluate tissue regeneration, and pantoprazole was chosen as one of the PPIs. GU was induced by oral administration of indomethacin once a day for 7 days. Rats in drug-administered groups were intraperitoneally injected with 100 μL normal saline, containing each drug at the indicated concentration, once a day for 14 days after inducing GU.

KEY FINDINGS

PDRN and PPI combination therapy potently improved tissue regeneration and inhibited production of pro-inflammatory cytokines. PDRN treatment with or without PPI increased the concentration of cyclic adenosine-3,5'-monophosphate (cAMP) and the ratio of phosphorylated cAMP response element-binding protein (p-CREB) to cAMP response element-binding protein (CREB). PDRN treatment with or without PPI also increased the expressions of vascular endothelial growth factor (VEGF) and adenosine A_2A receptor.

SIGNIFICANCE

PDRN and PPI combination therapy showed more potent therapeutic effect on GU compared to the PDRN monotherapy or PPI monotherapy. The excellent therapeutic effect of PDRN and PPI combination therapy on GU appeared by promoting regeneration of damaged tissue as well as inhibiting gastric acid secretion.

Comparison of wound healing effects between Oncorhynchus keta-derived polydeoxyribonucleotide (PDRN) and Oncorhynchus mykiss-derived PDRN

Background

Polydeoxyribonucleotide (PDRN) influencing cellular growth and differentiation is recognized to promote wound healing by stimulating tissue repair. Although PDRN can be extracted from human placentas, PDRN medications have recently been extracted from the semen of trout (Oncorhynchus mykiss) and salmon (Oncorhynchus keta). The present study was designed to evaluate the wound healing effects of O. keta-derived PDRN for injection (Rejuvenex) and PDRN cream (Rejuvenex Cream) in comparison with those of O. mykiss-derived PDRN injection (Placentex).

Methods

Full-thickness skin defects were made on the back of mice (n=60). The mice were divided into the following four groups according to the dressing used for the wounds: O. mykiss-derived PDRN injection group, O. keta-derived PDRN injection group, O. keta-derived PDRN cream group, and normal saline soaked dressing group (control group). We analyzed the gross findings, wound sizes, histological findings, immunohistochemistry and enzyme-linked immunosorbent assays for the groups immediately after the treatment, and again after 4, 7, and 10 days of treatment.

Results

The wound healing effects were the greatest in the O. keta-derived PDRN injection and O. mykiss-derived PDRN injection groups, which showed similar scores, followed by the O. keta-derived cream and normal saline soaked dressing groups.

Conclusion

The injection of PDRN extracted from O. keta was found to be as effective at healing full-thickness skin defects as the O. mykiss-derived PDRN injection, which is currently used in the clinic. Moreover, the O. keta-derived PDRN injection was also found to reduce the time required for wound healing.

Effects of salmon DNA fraction in vitro and in a monosodium iodoacetate-induced osteoarthritis rat model

PRF001 is a fragmented DNA polymer extracted from the testes of salmon. The purpose of this study was to assess the anti-inflammatory effect of PRF001 in vitro as well as the protective effect of PRF001 intake against arthritis in a rat model. In vitro, cell survival and inflammatory markers after H₂O₂ treatment to induce cell damage were investigated in CHON-001 cells treated with different concentrations of PRF001. In vivo, osteoarthritis was induced by intra-articular injection of monosodium iodoacetate (MIA) into the knee joints of rats. After consumption of PRF001 (10, 50, or 100 mg/kg) for 4 weeks, inflammatory mediators and cytokines in articular cartilage were investigated. In vitro, the levels of inflammatory markers, IL-1β, TNF-α, COX-2, iNOS, and PGE2, were significantly suppressed by PRF001 treatment. In vivo, the inflammatory mediators and cytokines, IL-1β, p-Erk1/2, NF-κB, TNF-α, COX-2, and PGE2, as well as MMP3 and MMP7, which have catabolic activity in chondrocytes, were decreased in the MIA-induced osteoarthritic rats following intake of PRF001. Histological analysis revealed that PRF001 had a protective effect on the articular cartilage. Altogether, these results demonstrated that the anti-inflammatory property of PRF001 contributes to its protective effects in osteoarthritis through deregulating IL-1β, TNF-α, and subsequent signals, such as p-Erk1/2, NF-κB, COX-2, PGE2, and MMPs.

Salvage of Unilateral Complete Ear Amputation with Continuous Local Hyperbaric Oxygen, Platelet-Rich Plasma and Polydeoxyribonucleotide without Micro-Revascularization

In many cases of complete ear amputation, microvascular surgery is required for tissue perfusion and organ survival. However, microvascular reconstruction is not always feasible in the absence of suitable vessels. Here, we present the case of a 76-year-old man who underwent complete amputation of the left ear after a collapse at home because of cardiogenic syncope. He was treated with primary replantation and underwent a postoperative salvage course including continuous local hyperbaric oxygen therapy (HBOT), platelet-rich plasma (PRP) injections, and polydeoxyribonucleotide (PDRN) injections. The ear was almost completely salvaged, with a tiny eschar at the mid-scapha on both the anterior and posterior aspects. This case demonstrates the efficacy of local HBOT with PRP and PDRN injections.

Viscoelastic interactions between polydeoxyribonucleotide and ophthalmic excipients

This study investigated the interaction between polydeoxyribonucleotide (PDRN) and several ionic and nonionic isotonic agents, thickeners and a preservative that were employed as excipients in ophthalmic preparations. Interaction of each individual excipient and PDRN aqueous solution was evaluated by analyzing their rheological properties. Rheological properties of PDRN solutions were evaluated by dynamic oscillatory shear tests and values of elastic modulus (G'), viscous modulus (G″) and loss tangent (tan δ) were used to assess the relative changes in viscoelastic properties. At given concentrations, sodium chloride was found to show alteration in viscoelastic properties of PDRN solution while nonionic isotonic agents like d-glucose and d-sorbitol did not alter them. Similarly, nonionic water soluble polymers like polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose (HPMC) also did not interact with PDRN to alter the viscoelastic properties. However, there were changes observed when carbopol 940 was used as a thickener. Therefore, PDRN was found to interact with ionic excipients and the interactions were negligible when nonionic materials were examined, which suggests that nonionic excipients are suitable to be formulated with PDRN.