Trophic effects of polynucleotides and hyaluronic acid in the healing of venous ulcers of the lower limbs: a clinical study

Current practices and perceived effectiveness of polynucleotides for treatment of facial erythema by cosmetic physicians

BACKGROUND

Polynucleotides (PN) are increasingly used for the treatment of facial erythema in the Republic of Korea. However, there are limited pre-clinical and clinical data on the efficacy of polynucleotides for facial erythema. In this study, we investigated the current practice and perceived effectiveness of polynucleotide treatment for facial erythema among cosmetic physicians.

METHODS

By conducting a survey among clinicians who use PN in clinical practice, we explored the current practices and assessed the perceived effectiveness of polynucleotides in treating facial erythema.

RESULTS

A total of 557 physicians who used polynucleotides for facial erythema participated in the survey. Polynucleotides were used by 84.4%, 66.4%, and 47.4% of physicians for facial erythema caused by inflammatory facial dermatosis, repeated laser/microneedle radiofrequency, and steroid overuse, respectively. Among those users, 88.1%, 90%, and 83.7% respectively in those same categories answered that polynucleotides were "highly effective" or "effective." Furthermore, they agreed that polynucleotides have the following properties: wound healing/regeneration (95.8%), protection of skin barrier (92.2%), hydration (90.5%), vascular stabilization (81.0%), and anti-inflammation (79.5%).

CONCLUSION

Our findings showed that cosmetic physicians in the Republic of Korea have used PN as a part of combination treatment for facial erythema resulting from inflammatory facial dermatosis and repeated laser/ microneedle radiofrequency, rather than from steroid overuse. Also, most clinicians agreed that PN was effective for treatment of facial erythema. Given the lack of pre-clinical and clinical trial evidence, the empirical responses of practicing physicians provide useful information to guide clinical practice and further research.

Dressings and topical agents containing hyaluronic acid for chronic wound healing

BACKGROUND

Hyaluronic acid is synthesised in plasma membranes and can be found in extracellular tissues. It has been suggested that the application of hyaluronic acid to chronic wounds may promote healing, and the mechanism may be due to its ability to maintain a moist wound environment which helps cell migration in the wound bed.

OBJECTIVES

To evaluate the effects of hyaluronic acid (and its derivatives) on the healing of chronic wounds.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was February 2022.

SELECTION CRITERIA

We included randomised controlled trials that compared the effects of hyaluronic acid (as a dressing or topical agent) with other dressings on the healing of pressure, venous, arterial, or mixed-aetiology ulcers and foot ulcers in people with diabetes.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 12 trials (13 articles) in a qualitative synthesis, and were able to combine data from four trials in a quantitative analysis. Overall, the included trials involved 1108 participants (mean age 69.60 years) presenting 178 pressure ulcers, 54 diabetic foot ulcers, and 896 leg ulcers. Sex was reported for 1022 participants (57.24% female). Pressure ulcers It is uncertain whether there is a difference in complete healing (risk ratio (RR) 1.17, 95% confidence interval (CI) 0.58 to 2.35); change in ulcer size (mean difference (MD) 25.60, 95% CI 6.18 to 45.02); or adverse events (none reported) between platelet-rich growth factor (PRGF) + hyaluronic acid and PRGF because the certainty of evidence is very low (1 trial, 65 participants). It is also uncertain whether there is a difference in complete healing between lysine hyaluronate and sodium hyaluronate because the certainty of evidence is very low (RR 2.50, 95% CI 0.71 to 8.83; 1 trial, 14 ulcers from 10 participants). Foot ulcers in people with diabetes It is uncertain whether there is a difference in time to complete healing between hyaluronic acid and lyophilised collagen because the certainty of evidence is very low (MD 16.60, 95% CI 7.95 to 25.25; 1 study, 20 participants). It is uncertain whether there is a difference in complete ulcer healing (RR 2.20, 95% CI 0.97 to 4.97; 1 study, 34 participants) or change in ulcer size (MD -0.80, 95% CI -3.58 to 1.98; 1 study, 25 participants) between hyaluronic acid and conventional dressings because the certainty of evidence is very low. Leg ulcers We are uncertain whether there is a difference in complete wound healing (RR 0.98, 95% CI 0.26 to 3.76), percentage of adverse events (RR 0.79, 95% CI 0.22 to 2.80), pain (MD 2.10, 95% CI -5.81 to 10.01), or change in ulcer size (RR 2.11, 95% CI 0.92 to 4.82) between hyaluronic acid + hydrocolloid and hydrocolloid because the certainty of evidence is very low (1 study, 125 participants). It is uncertain whether there is a difference in change in ulcer size between hyaluronic acid and hydrocolloid because the certainty of evidence is very low (RR 1.02, 95% CI 0.84 to 1.25; 1 study, 143 participants). We are uncertain whether there is a difference in complete wound healing between hyaluronic acid and paraffin gauze because the certainty of evidence is very low (RR 2.00, 95% CI 0.21 to 19.23; 1 study, 24 ulcers from 17 participants). When compared with neutral vehicle, hyaluronic acid probably improves complete ulcer healing (RR 2.11, 95% CI 1.46 to 3.07; 4 studies, 526 participants; moderate-certainty evidence); may slightly increase the reduction in pain from baseline (MD -8.55, 95% CI -14.77 to -2.34; 3 studies, 337 participants); and may slightly increase change in ulcer size, measured as mean reduction from baseline to 45 days (MD 30.44%, 95% CI 15.57 to 45.31; 2 studies, 190 participants). It is uncertain if hyaluronic acid alters incidence of infection when compared with neutral vehicle (RR 0.89, 95% CI 0.53 to 1.49; 3 studies, 425 participants). We are uncertain whether there is a difference in change in ulcer size (cm2) between hyaluronic acid and dextranomer because the certainty of evidence is very low (MD 5.80, 95% CI -10.0 to 21.60; 1 study, 50 participants). We downgraded the certainty of evidence due to risk of bias or imprecision, or both, for all of the above comparisons. No trial reported health-related quality of life or wound recurrence. Measurement of change in ulcer size was not homogeneous among studies, and missing data precluded further analysis for some comparisons.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to determine the effectiveness of hyaluronic acid dressings in the healing of pressure ulcers or foot ulcers in people with diabetes. We found evidence that hyaluronic acid probably improves complete ulcer healing and may slightly decrease pain and increase change in ulcer size when compared with neutral vehicle. Future research into the effects of hyaluronic acid in the healing of chronic wounds should consider higher sample size and blinding to minimise bias and improve the quality of evidence.

Clinical efficacy and safety of polynucleotides highly purified technology (PN-HPT®) and cross-linked hyaluronic acid for moderate to severe nasolabial folds: A prospective, randomized, exploratory study

INTRODUCTION

The mandibular profile undergoes progressive wasting with aging, and the deepening of nasolabial folds (NLFs) has a leading role. Hyaluronic acid (HA) efficiently controls tissue hydration and permeability to small and large molecules. NLFs are an acknowledged HA target; at the same time, another class of agents, PN-HPT® (Polynucleotides Highly Purified Technology), enjoy growing acknowledgement in aesthetic medicine. This exploratory, prospective study probed the rationale of sequentially associating PN-HPT® as a first priming agent acting in the skin followed by HA dermal filler injections for correcting moderate to severe NLFs.

METHODS

Following strict inclusion and exclusion criteria, the authors screened Caucasian ambulatory women aged 40-65 with moderate to severe NLFs and randomly selected two NLFs for each enrolled woman. Due to the purely explorative nature of the study, the authors initially planned to enroll no >10 women. According to a split-face design, the selected right-side NLFs received 4 ml of PN-HPT® intradermally in the initial priming phase ("NLF Rx group"); the selected left-side NLFs received 4 ml of saline (placebo) ("NLF Lx group"). After 3 and 6 weeks, all patients received 2 ml of subdermal cross-linked HA over both NLF areas (4 ml overall). The total study follow-up was 6 months after the first injection, with objective assessments, based on the qualitative and quantitative Antera 3D® and Vectra H2® skin imaging technologies, after 6 weeks and 3 and 6 months.

RESULTS

Because of the favorable early outcomes, the authors let enrollment progress between January and June 2020 up to a total of 20 women and 40 NLFs. All treated women completed the six-month follow-up without reporting side effects, even clinically minor. The Antera 3D® device demonstrated that wrinkles and skin texture significantly improved in the NLF Rx after 6 weeks (monotherapy phase) and 3 and 6 months (PN-HPT® priming + HA phase) compared with baseline. HA levels, measured with the quantitative Vectra H2® assessment technology in the right NLFs, were significantly higher than contralaterally at both 3 and 6 months.

CONCLUSIONS

Although conceived only as an exploratory investigation, the study confirmed that PN-HPT® monotherapy might be a valuable and effective option to rapidly improve the skin dermis texture and quality in individuals with moderate to severe NLFs. Acting as a priming agent in the skin, PN-HPT® prolong the clinical efficacy of cross-linked HA. Well-designed trials in larger treatment groups will hopefully confirm these early promising results.

Topical natural-origin polynucleotides in radiation-induced skin and mucosal toxicity

Seventy to 90 percent of patients who have received radiation treatment struggle with radiation skin and mucosal toxicity. The inflicted damage to progenitor cells and local microcirculation makes it more likely that wounds, infections, and fibrosis may occur; lesions of variable severity often co-exist. Acute erythema, hyperpigmentation, and mild desquamation usually wane in weeks and require only minor treatment. Conversely, the management of persistent radiation dermatitis and telangiectasia remains unsatisfactory; chronic lesions may progress to tissue atrophy and disfiguring fibrosis.

Efficacy and Safety of Using Noninsulated Microneedle Radiofrequency Alone Versus in Combination with Polynucleotides for the Treatment of Melasma: A Pilot Study

Introduction

This split-face, double-blind, randomized controlled study investigated the efficacy and safety of using a microneedling radiofrequency (RF) device with polynucleotides (PN) versus RF alone for the treatment of melasma.

Methods

Thirty adult participants with melasma (Fitzpatrick skin types III–V) received three treatments with an invasive, bipolar, pulsed-type microneedling RF device on both sides of the face. The treatment sessions occurred once every 2 weeks. The hemifaces of each participant were designated for treatment and control with PN and normal saline solution (NSS), applied after treatment with RF. Measurements were made of melanin index (MI), erythema index (EI), skin roughness (by the Antera 3D system), modified melasma area severity index (mMASI) for each hemiface, and patients’ self-assessed improvement. These occurred at baseline and again following the final treatment (2 weeks and 1, 2, 3, and 6 months after). Mean values were obtained for MI, EI, skin roughness, and mMASI. A generalized estimating equation (GEE) was used to compare the obtained values for the outcome measures across all assessment points.

Results

All patients were women (mean age, 43.2 ± 7.0 years). Mixed melasma predominated (61.5%; n = 16), and the mean duration of melasma was 8.9 ± 6.5 years. Twenty-six participants were followed up to the 6-month assessment point. Significant improvements were observed from baseline in MI, skin roughness, and mMASI scores for both the PN and control sides at 6 months, with no statistically significant differences between sides. Patients’ self-assessed improvement scores also showed a positive trend. Melasma recurrence was observed in three patients at 2, 3, and 4 months after the last treatment session (10% recurrence rate).

Conclusions

The combination of an invasive, bipolar, pulsed-type microneedling RF with PN is not superior compared with microneedling RF alone in the treatment of melasma. Microneedling RF may be considered as safe and efficacious for the improvement of skin roughness, and as an adjunctive treatment option for melasma.

Clinical Trial Registration

This study was registered on ClinicalTrials.gov and assigned NCT number TCTR20210804002.

Preliminary Prospective and Randomized Study of Highly Purified Polynucleotide vs Placebo in Treatment of Moderate to Severe Acne Scars

BACKGROUND

Managing acne scars is a challenge and therapies are divided into nonsurgical and surgical. Highly Purified Technology Polynucleotides (PN-HPT) is a compound that contains a mixture of DNA polymers of different lengths. Numerous studies have shown that PN-HPT also serves as an energy source, thus influencing cellular growth and cell vitality.

OBJECTIVES

The authors aimed to assess the improvement in dermal quality and acne scars after PN-HPT vs placebo according to Antera 3D and the patient responses to the patient satisfaction questionnaire after a comparison of pretreatment and posttreatment photographs at 1 and 3 months.

METHODS

Included were women aged 30 to 50 years with grade 3 to 4 moderate-to-severe atrophic scars according to the Goodman classification; nonsmokers; and had not had active acne during the past 5 years. Ten patients (PN-HPT group) were treated with 4.0 mL of PN-HPT, and 10 patients (control) were treated with 4.0 mL of normal saline. All medical treatments were performed in a double-blinded manner; neither the injection doctor nor the patient knew if the PN-HPT or the placebo was being administered.

RESULTS

Twenty women who fit the inclusion criteria were enrolled in this study. Only patients in the PN-HPT group improved significantly at 1 and 3 months after treatment compared with baseline.

CONCLUSIONS

This prospective and randomized study showed that PN-HPT in monotherapy was safe and effective treatment for atrophic scar acne compared with placebo. Prospective and randomized studies will be necessary to investigate the clinical effectiveness in a larger cohort of patients and for a longer follow-up.

LEVEL OF EVIDENCE: 2

Bone regeneration in ceramic scaffolds with variable concentrations of PDRN and rhBMP-2

This study evaluated the bone regeneration capacity and mechanical properties of block-type hydroxyapatite (HA)/tricalcium phosphate (TCP) scaffolds in response to different concentrations of polydeoxyribonucleotide (PDRN) and recombinant human bone morphogenic protein 2 (rhBMP-2). Thirty-two male white rabbits were used as a model of calvarial bone defect and classified into eight groups according to type and concentration of growth factor administered, viz., control group (only HA/TCP scaffold), scaffold + PDRN (0.1, 1, 5, and 10 mg/mL each) and scaffold + rhBMP-2 (0.01, 0.05, and 0.1 mg/mL each). The specimens were evaluated using histomorphometric and radiological analyses. Histomorphometric analyses indicated that the administration of PDRN did not increase bone formation. However, significant increases in bone formation were observed with the administration of rhBMP-2 at 0.05 and 0.10 mg/mL on week 8 compared to the control (p < 0.05). Radiological analyses revealed a significant increase in bone formation at week 8 with the administration of PDRN at 5 mg/mL and 10 mg/mL, and rhBMP-2 at 0.05 or 0.10 mg/mL compared to the control (p < 0.05). Our findings show that block-type HA/TCP scaffolds possess sufficient mechanical strength and bone regeneration capacity when used with optimal concentrations of growth factors.

Use of cord blood platelet gel to enhance healing of deep surgical site dehiscences after peripheral bypass

Surgical site dehiscence after lower limb revascularization through bypass represents a serious postoperative complication, especially in diabetic and obese patients, with subsequent risk of early graft failure, infection, sepsis, hemorrhage, major amputation and sometimes death. To prevent bypass exposure and subsequent complications, physicians recur to reoperation, antibiotic therapy, advanced dressing and vacuum-assisted closure therapy. To improve the process of wound healing, cord blood platelet gel can be used to fill deep and large wounds. Growth factors released from platelets in the cord blood platelet gel stimulate the process of healing and allow patients to be followed up in Outpatient Surgery, thus reducing hospital stay and costs, while providing excellent results.

Consensus report on the use of PN-HPT™ (polynucleotides highly purified technology) in aesthetic medicine

Background

Injective procedures using polynucleotides‐based products to promote dermal rejuvenation and revitalization are steadily evolving, yet no structured protocols are available that discuss and provide guidance in aesthetic treatments with highly purified polynucleotides. The goal of this document was to provide consensus‐based recommendations for the safe and effective use of Polynucleotides Highly Purified Technology™ (PN‐HPT™) devices for skin rejuvenation.

Patients/Methods

A team of eight experts with extensive experience in treatments for skin rejuvenation and revitalization integrated the best available evidence and clinical judgment and devised a series of practical guidance to support dermatologists, plastic surgeons, and aesthetic physician in the use of PN‐HPT™ products, alone and in combination, in aesthetic medicine.

Results

For most items, the expert group achieved a majority consensus. “Recommendations” (consensus >80%) were reached for the face, periocular area, décolleté and neck, hands, scalp, and stretch marks. Recommendations include details of techniques, information on dosage, volumes to be injected, and the ideal number of required treatment sessions, as well as time intervals between them for different areas of face and body. A lower agreement level of 60% was reached on but one item related to the initial treatment cycle for the face, leading to a “Consensus statement” for that area instead of a full “Recommendation.”

Conclusion

The expert consensus illustrates the value of natural‐origin, highly purified polynucleotides (PN‐HPT™) as biostimulatory booster strategy for skin priming and revitalization of face and body and provides a detailed guide for the use.

The use of acellular porcine dermis, hyaluronic acid and polynucleotides in the treatment of cutaneous ulcers: Single blind randomised clinical trial

Reconstruction of chronic ulcers is often hampered by lack of local tissues and poor general conditions. Conservative approaches with debridement and advanced medications, such as polyurethane foam, stand as mainstays. However, the healing process is often slow, thus increasing the risk for infection or other complications. In such cases, porcine dermis (PD) and polynucleotides-added hyaluronic acid (PAHA) were previously reported to accelerate healing. The aim of the study was to compare the efficacy of PD, PAHA and polyurethane foam in chronic ulcers. Thirty patients were randomly divided into 3 groups: group 1 was treated with advanced medications, group 2 with PD, group 3 with PAHA. Standardised photographs and biopsies were taken before treatment and at 30-day follow-up. Photographs were processed to calculate the wound area. Specimens were stained with Haematoxylin/Eosin, Masson trichrome, and immunohistochemically for CD34, alpha-Smooth Muscle Actin (α-SMA), Collagen types I and III, Ki67. The re-epithelialized area was larger in patients treated with PD and PAHA compared with those treated with polyurethane foam (P < .05 and P < .01, respectively). Specimens from patients treated with PD and PAHA showed a higher number of myofibroblasts (α-SMA+, P < .01), neo-angiogenesis (CD34+, P < .01), proliferating dermal cells (Ki67+, P < .01), proliferating keratinocytes (Ki67+, P < .01) and collagen type 1 deposition (P < .05). No difference was found between PD and PAHA. PD and PAHA proved to be more effective than polyurethane foam in the treatment of chronic ulcers. These approaches are a versatile and reliable option to address such cases.

Efficacy of Intra-Articular Polynucleotides Associated With Hyaluronic Acid Versus Hyaluronic Acid Alone in the Treatment of Knee Osteoarthritis: A Randomized, Double-Blind, Controlled Clinical Trial

OBJECTIVE

Pain and range of motion loss are the main clinical features of osteoarthritis (OA). Hyaluronic acid (HA) is one of the infiltrative therapies for OA treatment; however, its effectiveness is a matter of an ongoing debate in clinical practice. Polynucleotides (PNs), a DNA-derived macromolecule with natural origin and trophic activity, were found to favor cell growth and collagen production, in preclinical and clinical studies regarding cartilage regeneration. This study aimed at evaluating whether injection of PNs, in combination with HA [PNs associated with HA (PNHA)], can ameliorate pain and function of knees affected by OA, more than HA alone.

DESIGN

A randomized, double-blind, controlled clinical trial.

PATIENTS

The study enrolled 100 patients, then randomized to receive PNHA or HA alone (3 weekly knee I.A. injections).

INTERVENTIONS AND MAIN OUTCOME MEASURES

Pain reduction, decrease of proinflammatory synovial fluid (SF) factors, and improvement in knee function were evaluated by Knee Society Score and WOMAC scores, after 2, 6, and 12 months and by biochemical and immunoenzymatic analyses of SF at the end of the treatment.

RESULTS

Knee Society Score total score and pain item significantly ameliorated in both groups, showing better results in PNHA- than in the HA-treated group. A significant reduction in the WOMAC score was observed over time for both groups. No significant adverse events were reported in either group.

CONCLUSIONS

These findings suggest that I.A. injection of PNs, in combination with HA, is more effective in improving knee function and pain, in a joint affected by OA, compared with HA alone.

An effective range of polydeoxyribonucleotides is critical for wound healing quality

Wound healing is a physiological restorative response to tissue and cell injury. This process occurs in collaboration with a complex cascade of cellular events, including biochemical alterations to the extracellular matrix. Polydeoxyribonucleotide (PDRN) is a fragmented DNA mixture from Oncorhynchus mykiss or Oncorhynchus keta sperm known to promote tissue regeneration under different pathophysiological conditions. However, the most effective molecular size of PDRNs for promoting the wound healing process and quality has not been established. In the present study, the regeneration quality with low (<50 kDa), middle [classic PDRN; 50‑1,500 kDa] and high (>1,500 kDa) molecular weight PDRNs in a skin wound healing mouse model was examined using hematoxylin and eosin, as well as Masson's trichrome stain. A 4 mm biopsy punch was used to produce wounds in the skin of the mice. PDRN‑mediated cellular behavior and signaling were evaluated by in vitro scratch assay and western blot analysis, respectively. It was observed that the apparent surface wound healing processes were not significantly different between PDRN molecular sizes. Immunohistochemical analysis revealed that classic PDRN‑injected mice exhibited less lipid accumulation with increased collagen composition. These results suggested that 50‑1,500 kDa PDRN offers an effective DNA mixture to improve wound healing quality. Furthermore, classic PDRN increased cell migration via c‑Jun N‑terminal kinase signaling in human fibroblasts. The present study suggests an optimal PDRN molecular weight to promote wound healing, and novel approaches for therapeutic strategies to improve tissue regeneration quality.

Dressings and topical agents for treating venous leg ulcers

BACKGROUND

Venous leg ulcers are open skin wounds on the lower leg which can be slow to heal, and are both painful and costly. The point prevalence of open venous leg ulcers in the UK is about 3 cases per 10,000 people, and many people experience recurrent episodes of prolonged ulceration. First-line treatment for venous leg ulcers is compression therapy, but a wide range of dressings and topical treatments are also used. This diversity of treatments makes evidence-based decision-making challenging, and a clear and current overview of all the evidence is required. This review is a network meta-analysis (NMA) which assesses the probability of complete ulcer healing associated with alternative dressings and topical agents.

OBJECTIVES

To assess the effects of (1) dressings and (2) topical agents for healing venous leg ulcers in any care setting and to rank treatments in order of effectiveness, with assessment of uncertainty and evidence quality.

SEARCH METHODS

In March 2017 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also scanned reference lists of relevant included studies as well as reviews, meta-analyses, guidelines and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting. We updated this search in March 2018; as a result several studies are awaiting classification.

SELECTION CRITERIA

We included published or unpublished randomised controlled trials (RCTs) that enrolled adults with venous leg ulcers and compared the effects of at least one of the following interventions with any other intervention in the treatment of venous leg ulcers: any dressing, or any topical agent applied directly to an open venous leg ulcer and left in situ. We excluded from this review dressings attached to external devices such as negative pressure wound therapies, skin grafts, growth factors and other biological agents, larval therapy and treatments such as laser, heat or ultrasound. Studies were required to report complete wound healing to be eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment and data extraction. We conducted this NMA using frequentist meta-regression methods for the efficacy outcome; the probability of complete healing. We assumed that treatment effects were similar within dressings classes (e.g. hydrocolloid, foam). We present estimates of effect with their 95% confidence intervals (CIs) for individual treatments focusing on comparisons with widely used dressing classes, and we report ranking probabilities for each intervention (probability of being the best, second best, etc treatment). We assessed the certainty (quality) of the body of evidence using GRADE for each network comparison and for the network as whole.

MAIN RESULTS

We included 78 RCTs (7014 participants) in this review. Of these, 59 studies (5156 participants, 25 different interventions) were included in the NMA; resulting in 40 direct contrasts which informed 300 mixed-treatment contrasts.The evidence for the network as a whole was of low certainty. This judgement was based on the sparsity of the network leading to imprecision and the general high risk of bias in the included studies. Sensitivity analyses also demonstrated instability in key aspects of the network and results are reported for the extended sensitivity analysis. Evidence for individual contrasts was mainly judged to be low or very low certainty.The uncertainty was perpetuated when the results were considered by ranking the treatments in terms of the probability that they were the most effective for ulcer healing, with many treatments having similar, low, probabilities of being the best treatment. The two most highly-ranked treatments both had more than 50% probability of being the best (sucralfate and silver dressings). However, the data for sucralfate was from one small study, which means that this finding should be interpreted with caution. When exploring the data for silver and sucralfate compared with widely-used dressing classes, there was some evidence that silver dressings may increase the probability of venous leg ulcer healing, compared with nonadherent dressings: RR 2.43, 95% CI 1.58 to 3.74 (moderate-certainty evidence in the context of a low-certainty network). For all other combinations of these five interventions it was unclear whether the intervention increased the probability of healing; in each case this was low- or very low-certainty evidence as a consequence of one or more of imprecision, risk of bias and inconsistency.

AUTHORS' CONCLUSIONS

More research is needed to determine whether particular dressings or topical agents improve the probability of healing of venous leg ulcers. However, the NMA is uninformative regarding which interventions might best be included in a large trial, largely because of the low certainty of the whole network and of individual comparisons.The results of this NMA focus exclusively on complete healing; whilst this is of key importance to people living with venous leg ulcers, clinicians may wish to take into account other patient-important outcomes and factors such as patient preference and cost.

Efficacy of cord blood platelet gel application for enhancing diabetic foot ulcer healing after lower limb revascularization

The efficacy of umbilical cord blood platelet gel (CBPG) application on healing foot ulcers was analyzed in 10 diabetic patients treated for critical lower limb ischemia by surgical or endovascular arterial revascularization. During a 9-month period, 20 diabetic patients affected by critical lower limb ischemia with tissue loss were enrolled in this nonblinded, consecutive series, randomized clinical trial. After clinical evaluation, patients underwent endovascular or surgical revascularization of the affected limb, followed by minor amputations or surgical debridement of ischemic lesions. Patients were then randomly divided into two groups: 10 patients in Group A treated with standard wound care and 10 patients in Group B treated with topic application of CBPG. The CBPG protocol consisted of platelet gel application twice a week for 4 weeks and then once a week for an additional 4 weeks. Healing was assessed by direct ulcer dimension tracing onto clear plastic sheet and subsequent computerized planimetry. The mean pretreatment and post-treatment ulcer areas at 30 days for Group A were 15.1 cm² and 8.1 cm², respectively, and for Group B were 15.7 cm² and 3.25 cm², respectively; resulting in a mean ulcer area reduction of 46% for Group A and 79% for Group B patients (P < .01). These observations suggest CBPG application can promote more rapid wound healing than standard care, and indicate the need for a randomized, multicenter trial to confirm clinical efficacy.

Pharmacological Activity and Clinical Use of PDRN

PDRN is a proprietary and registered drug that possesses several activities: tissue repairing, anti-ischemic, and anti-inflammatory. These therapeutic properties suggest its use in regenerative medicine and in diabetic foot ulcers. PDRN holds a mixture of deoxyribonucleotides with molecular weights ranging between 50 and 1,500 KDa, it is derived from a controlled purification and sterilization process of Oncorhynchus mykiss (Salmon Trout) or Oncorhynchus keta (Chum Salmon) sperm DNA. The procedure guarantees the absence of active protein and peptides that may cause immune reactions. In vitro and in vivo experiments have suggested that PDRN most relevant mechanism of action is the engagement of adenosine A_2A receptors. Besides engaging the A_2A receptor, PDRN offers nucleosides and nucleotides for the so called “salvage pathway.” The binding to adenosine A_2A receptors is a unique property of PDRN and seems to be linked to DNA origin, molecular weight and manufacturing process. In this context, PDRN represents a new advancement in the pharmacotherapy. In fact adenosine and dipyridamole are non-selective activators of adenosine receptors and they may cause unwanted side effects; while regadenoson, the only other A_2A receptor agonist available, has been approved by the FDA as a pharmacological stress agent in myocardial perfusion imaging. Finally, defibrotide, another drug composed by a mixture of oligonucleotides, has different molecular weight, a DNA of different origin and does not share the same wound healing stimulating effects of PDRN. The present review analyses the more relevant experimental and clinical evidences carried out to characterize PDRN therapeutic effects.

Polydeoxyribonucleotides (PDRNs) From Skin to Musculoskeletal Tissue Regeneration via Adenosine A2A Receptor Involvement

Polydeoxyribonucleotides (PDRNs) are low molecular weight DNA molecules of natural origin that stimulate cell migration and growth, extracellular matrix (ECM) protein production, and reduce inflammation. Most preclinical and clinical studies on tissue regeneration with PDRNs focused on skin, and only few are about musculoskeletal tissues. Starting from an overview on skin regeneration studies, through the analysis of in vitro, in vivo, and clinical studies (1990-2016), the present review aimed at defining the effects of PDRN and their mechanisms of action in the regeneration of musculoskeletal tissues. This would also help future researches in this area. A total of 29 studies were found by PubMed and www.webofknowledge.com searches: 20 were on skin (six in vitro, six in vivo, one vitro/vivo, seven clinical studies), while the other nine regarded bone (one in vitro, two in vivo, one clinical studies), cartilage (one in vitro, one vitro/vivo, two clinical studies), or tendon (one clinical study) tissues regeneration. PDRNs improved cell growth, tissue repair, ECM proteins, physical activity, and reduced pain and inflammation, through the activation of adenosine A_2A receptor. PDRNs are currently used for bone, cartilage, and tendon diseases, with a great variability regarding the PDRN dosage to be used in clinical practice, while the dosage for skin regeneration is well established. PDRNs are usually administered from a minimum of three to a maximum of five times and they act trough the activation of A_2A receptor. Further studies are advisable to confirm the effectiveness of PDRNs and to standardize the PDRN dose. J. Cell. Physiol. 232: 2299-2307, 2017. © 2016 Wiley Periodicals, Inc.

Application of autologous platelet-rich plasma to enhance wound healing after lower limb revascularization: A case series and literature review

Dermal tissue loss in patients affected by critical limb ischemia represents a serious wound-healing problem, with high morbidity, prolonged hospital stay, and high patient care costs. Treatment of ischemic foot lesions requires limb revascularization by endovascular or open surgical intervention and individualized patient-specific wound care, including antibiotic therapy; devitalized/infected wound debridement; and advanced wound dressing. In selected patients, spinal cord stimulation, vacuum-assisted closure therapy, and bioengineered tissue or skin substitutes and growth factors have been shown to improve wound healing. In this study, we present our preliminary results on topical application of autologous platelet-rich plasma to enhance the process of wound healing after revascularization of lower limbs in patients affected by critical limb ischemia.