Sildenafil in the treatment of pressure ulcer: a randomised clinical trial

Bifunctional Sildenafil Diazeniumdiolates Acting as Phosphodiesterase 5 Inhibitors and Nitric Oxide Donors- Towards Wound Healing

Inefficient wound healing poses a global health challenge with a lack of efficient treatments. Wound healing issues often correlate with low endogenous nitric oxide (NO) levels. While exogenous delivery with NO-releasing compounds represents a promising therapeutic strategy, controlling the release of the highly reactive NO remains challenging. Phosphodiesterase 5 (PDE5) inhibitors, like sildenafil, have also been shown to promote wound healing. This study explores hybrid compounds, combining NO-releasing diazeniumdiolates with a sildenafil-derived PDE5 inhibitor. One compound demonstrated a favorable NO-release profile, triggered by an esterase (prodrug), and displayed in vitro nanomolar inhibition potency against PDE5 and thrombin-induced platelet aggregation. Both factors are known to promote blood flow and oxygenation. Thus, our findings unveil promising prospects for effective wound healing treatments.

A Dual-Acting Nitric Oxide Donor and Phosphodiesterase 5 Inhibitor Activates Autophagy in Primary Skin Fibroblasts

Wound healing pathologies are an increasing problem in ageing societies. Chronic, non-healing wounds, which cause high morbidity and severely reduce the quality of life of affected individuals, are frequently observed in aged individuals and people suffering from diseases affected by the Western lifestyle, such as diabetes. Causal treatments that support proper wound healing are still scarce. Here, we performed expression proteomics to study the effects of the small molecule TOP-N53 on primary human skin fibroblasts and keratinocytes. TOP-N53 is a dual-acting nitric oxide donor and phosphodiesterase-5 inhibitor increasing cGMP levels to support proper wound healing. In contrast to keratinocytes, which did not exhibit global proteome alterations, TOP-N53 had profound effects on the proteome of skin fibroblasts. In fibroblasts, TOP-N53 activated the cytoprotective, lysosomal degradation pathway autophagy and induced the expression of the selective autophagy receptor p62/SQSTM1. Thus, activation of autophagy might in part be responsible for beneficial effects of TOP-N53.

Products and technologies for treating patients with evidence-based pressure ulcers

OBJECTIVE

to identify products/technologies for treating patients with pressure ulcers with an evidence level 1.

METHOD

this is an integrative literature review. A survey of studies was carried out using the United States National Library of Medicine Portal, Scientific Electronic Library Online, Virtual Health Library, National Library of Medicine(®), The Cumulative Index to Nursing and Allied Health Literature, Latin American and Caribbean in Health Sciences, Nursing Database.

RESULTS

sixteen articles were selected with level of evidence 1. The findings were categorized into five categories: Topical therapy to promote healing; Alternative therapy to promote healing; Topical therapy to promote debridement; Topical therapy to minimize lesion contamination; Topical therapy to reduce lesion size.

FINAL CONSIDERATIONS

the 17 products/technologies identified favor/fast healing, debridement, minimize contamination and reduce lesion size to accelerate healing.

Effects of sildenafil and tadalafil on skin flap viability

Vascular complication is one of the causes of skin flap healing failure. Sildenafil and tadalafil, a type-5 phosphodiesterase inhibitor, can improve flap viability, however, the action mechanisms involved in this process are still unclear. To assess the effects of orally administered sildenafil and tadalafil on the healing kinetics and skin flap viability, sixty-two Wistar rats were divided into three groups: control (n = 22), sildenafil (n = 20), and tadalafil (n = 20). The solutions were administered orally (dose: 10 mg/kg) immediately after the surgical procedure and then every 24 h. At postoperative days 7 and 14, the skin flap samples were collected, submitted to histological processing and evaluated under optical microscopy. In experimental groups (sildenafil and tadalafil), we found an increased vascularization (p < 0.05) on the 7th and 14th day associated with the ulcer size decrease on the 14th day, although it was not significant. There was a higher influx of neutrophils and a decrease of mononuclear population on the 7th day (p < 0.05). On the 14th day, these differences were observed only in the tadalafil group (p < 0.05). This study suggested positive results with the use of sildenafil and tadalafil as adjuvant drugs in skin flap viability.

Topical Nifedipine for the Treatment of Pressure Ulcer: A Randomized, Placebo-Controlled Clinical Trial

BACKGROUND

Effect of nifedipine on pressure ulcer (PU) healing has not been evaluated in the human subjects yet.

STUDY QUESTION

In this study, the effect of topical application of nifedipine 3% ointment on PU healing in critically ill patients was investigated.

STUDY DESIGN

This was a randomized, double-blind, placebo-controlled clinical.

MEASURES AND OUTCOMES

In this study, 200 patients with stage I or II PU according to 2-digit Stirling Pressure Ulcer Severity Scale were randomized to receive topical nifedipine 3% ointment or placebo twice daily for 14 days. Changes in the size and stage of the ulcers were considered as primary outcome of the study. The stage of the ulcers at baseline and on day 7 and day 14 of study was determined by using 2-digit stirling scale. In addition, the surface area of the wounds was estimated by multiplying width by length.

RESULTS

In total, 83 patients in each group completed the study. The groups were matched for the baseline stage and size of PUs. Mean decrease in the stage of PU in the nifedipine group was significantly higher than the placebo group on day 7 (-1.71 vs. -0.16, respectively, P < 0.001) and day 14 (-0.78 vs. -0.09, respectively, P < 0.001). Furthermore, the mean decrease in the surface area of PU was significantly higher in the nifedipine group compared with the placebo group on day 7 (-1.44 vs. -0.32, respectively, P < 0.001) and day 14 (-2.51 vs. -0.24, respectively, P < 0.001) of study.

CONCLUSIONS

Topical application of nifedipine 3% ointment for 14 days significantly improved the healing process of stage I or II PUs in critically ill patients.

A Dual-Acting Nitric Oxide Donor and Phosphodiesterase 5 Inhibitor Promotes Wound Healing in Normal Mice and Mice with Diabetes

Chronic wounds affect a large percentage of the population worldwide and cause significant morbidity. Unfortunately, efficient compounds for the treatment of chronic wounds are yet not available. Endothelial dysfunction, which is at least in part a result of compromised nitric oxide production and concomitant reduction in cGMP levels, is a major pathologic feature of chronic wounds. Therefore, we designed and synthesized a compound with a unique dual-acting activity (TOP-N53), acting as a nitric oxide donor and phosphodiesterase 5 inhibitor, and applied it locally to full-thickness skin wounds in healthy and healing-impaired mice with diabetes. TOP-N53 promoted keratinocyte proliferation, angiogenesis, and collagen maturation in healthy mice without accelerating the wound inflammatory response or scar formation. Most importantly, it partially rescued the healing impairment of mice with genetically determined type II diabetes (db/db) by stimulating re-epithelialization and granulation tissue formation, including angiogenesis. In vitro studies with human and murine primary cells showed a positive effect of TOP-N53 on keratinocyte and fibroblast migration, keratinocyte proliferation, and endothelial cell migration and tube formation. These results demonstrate a remarkable healing-promoting activity of TOP-N53 by targeting the major resident cells in the wound tissue.

Effectiveness of Topical Sucralfate in the Management of Pressure Ulcer in Hospitalized Patients: A Prospective, Randomized, Placebo-Controlled Trial

BACKGROUND

The aim of this study was to evaluate the effectiveness of topical sucralfate in the management of pressure ulcer (PU) in hospitalized patients.

METHODS

Forty hospitalized patients with stage II PU were included in this prospective, double-blind, randomized, placebo-controlled trial and were randomly divided into 2 groups receiving either sucralfate gel or placebo, on a daily basis. The patients were visited every day for 14 days, the ulcer was evaluated using the Pressure Ulcer Scale for Healing (PUSH) and changes to the measured scores over time were used as an indicator of wound healing.

RESULTS

There were no statistically significant differences in any of the demographic characteristics between both groups. Both of the interventions reduced the average PUSH score, and at the end of the trial, all but 2 patients were healed. One in each group discontinued the trial because of exacerbation of the ulcer. No significant between-group difference in the average PUSH score reduction was observed (6.36 ± 2.11 vs. 5.89 ± 1.41, P = 0.42). Although the average healing time was less in the sucralfate group (6.05 ± 2.17 vs. 7.78 ± 3.42), the difference was not statistically significant (P = 0.07).

CONCLUSIONS

Sucralfate gel does not improve healing of PU compared with placebo.

Tissue Engineered Skin Substitutes

The fundamental skin role is to supply a supportive barrier to protect body against harmful agents and injuries. Three layers of skin including epidermis, dermis and hypodermis form a sophisticated tissue composed of extracellular matrix (ECM) mainly made of collagens and glycosaminoglycans (GAGs) as a scaffold, different cell types such as keratinocytes, fibroblasts and functional cells embedded in the ECM. When the skin is injured, depends on its severity, the majority of mentioned components are recruited to wound regeneration. Additionally, different growth factors like fibroblast growth factor (FGF), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) are needed to orchestrated wound healing process. In case of large surface area wounds, natural wound repair seems inefficient. Inspired by nature, scientists in tissue engineering field attempt to engineered constructs mimicking natural healing process to promote skin restoration in untreatable injuries. There are three main types of commercially available engineered skin substitutes including epidermal, dermal, and dermoepidermal. Each of them could be composed of scaffold, desired cell types or growth factors. These substitutes could have autologous, allogeneic, or xenogeneic origin. Moreover, they may be cellular or acellular. They are used to accelerate wound healing and recover normal skin functions with pain relief. Although there are a wide variety of commercially available skin substitutes, almost none of them considered as an ideal equivalents required for proper wound healing.

Current Status and Future of Skin Substitutes for Chronic Wound Healing

Chronic wounds, including diabetic ulcers, pressure ulcers, venous ulcers, and arterial insufficiency ulcers, are both difficult and expensive to treat. Conventional wound care may sometimes lead to suboptimal wound healing and significant morbidity and mortality for patients. The use of skin substitutes provides an alternative therapy showing superior efficacy and, in some cases, similar cost-effectiveness compared to traditional treatments. This review discusses the different types of currently available commercial skin substitutes for use in chronic wounds as well as the paucity of strong evidence supporting their use. It then delves into the limitations of these skin substitutes and examines the most recent research targeting these limitations.

Useful Implications of Low-dose Long-term Use of PDE-5 Inhibitors

INTRODUCTION

Phosphodiesterase type 5 (PDE-5) hydrolyzes cyclic guanylate monophosphate (cGMP) specifically to 5' GMP, promoting successful corporeal vascular relaxation and penile erection during sexual stimulation. Oral PDE-5 inhibitors such as sildenafil, vardenafil, tadalafil, and avanafil have provided noninvasive, effective, well-tolerated treatment for erectile dysfunction (ED) patients and, at the same time, stimulated both academic and clinical interests. Lately, some oral PDE-5 inhibitors were released as low-dose preparations with the concept of potential daily administration and long-term use.

AIM

To highlight the possible potential implications of low-dose long-term use of PDE-5 inhibitors.

METHOD

A systematic review was carried out until December 2015 based on a search of all concerned articles in MEDLINE, medical subjects heading (MeSH) databases, Scopus, The Cochrane Library, EMBASE, and CINAHL databases without language restriction. Key words used to assess the outcome and estimates for concerned associations were: PDE-5 inhibitors; erectile dysfunction; low-dose; long-term; sildenafil; tadalafil; vardenafil; avanafil.

MAIN OUTCOME MEASURES

Demonstrating different implications for low-dose long-term use of PDE-5 inhibitors.

RESULTS

Low-dose and/or long-term use of PDE-5 inhibitors was shown to put forth beneficial sound effects in different medical implications with potentials that could be extended for different utilities. These implications included sexual, urogenital, cardiovascular, pulmonary, cutaneous, gastrointestinal, and reproductive, as well as neurological disorders. However, it is evident that most potential appliances were carried out experimentally on preclinical studies with off-label indications.

CONCLUSION

Making use of and exploring low-dose and/or long-term use of several PDE-5 inhibitors for their possible implications seem to be valuable in different medical disorders. Increased knowledge of the drug characteristics, comparative treatment regimens, optimal prescribing patterns, and well-designed clinical trials are needed before these agents can be recommended for use.

The effect of nitric oxide releasing cream on healing pressure ulcers

BACKGROUND

Pressure ulcer is one of the main concerns of nurses in medical centers around the world, which, if untreated, causes irreparable problems for patients. In recent years, nitric oxide (NO) has been proposed as an effective method for wound healing. This study was conducted to determine the effect of nitric oxide on pressure ulcer healing.

MATERIALS AND METHODS

In this clinical trial, 58 patients with pressure ulcer at hospitals affiliated to Ahvaz Jundishapur University of Medical Sciences were homogenized and later divided randomly into two groups of treatment (nitric oxide cream; n = 29) and control (placebo cream; n = 29). In this research, the data collection tool was the Pressure Ulcer Scale for Healing (PUSH). At the outset of the study (before using the cream), the patients' ulcers were examined weekly in terms of size, amount of exudates, and tissue type using the PUSH tool for 3 weeks. By integrating these three factors, wound healing was determined. Data were analyzed using SPSS.

RESULTS

Although no significant difference was found in terms of the mean of score size, the amount of exudates, and the tissue type between the two groups, the mean of total score (healing) between the two groups was statistically significant (P = 0.04).

CONCLUSIONS

Nitric oxide cream seems to accelerate wound healing. Therefore, considering its easy availability and cost-effectiveness, it can be used for treating pressure ulcers in the future.

Tadalafil therapy and severe chronic foot wound resolution

We report an unanticipated medication effect resulting in near-complete wound healing in a patient after beginning tadalafil therapy of 20 mg thrice daily. This patient was treated for 50 years with state-of-the art acute and then chronic wound interventions after a traumatic farm machinery accident which resulted in a devascularised foot wound. This infection was both life- and limb-threatening. The patient had undergone multiple vascular and plastic surgeries and antimicrobial therapies in addition to hospitalisations for sepsis. Limb amputation was being considered, when his urologist placed him on daily phosphodiesterase-5 inhibitor therapy, prior to unrelated urologic surgery. Remarkably, his foot wound underwent near-complete resolution and has been stable for 2 years.

Effect of topically applied sildenafil citrate on wound healing: experimental study

Wound healing is a complex process that necessitates organization of different cell types and several signalling molecules. The aim of this study is to evaluate the effect of different concentrations of sildenafil citrate, which decreases cGMP degradation, on wound healing by secondary intention.This study was performed using 25 Sprague Dawley rats weighing 200-250 grams. 4 dorsal defects were created. Four different treatment modalities which were 1% and 5% sildenafil citrate gel prepared with carbopol, pure carbopol gel without any drug in it and 0,9% NaCl solution; were applied to each lesion of the same rat. Randomly selected five rats (25 rats in total) were sacrificed on 3rd, 5th, 7th, 10th, and 14th days; and the effect of each modality was evaluated by means of defect area measurement, histopathological examination and measurement of tissue hydroxyproline levels.Sildenafil citrate gel application decreased the defect areas in a dose independent manner starting from 3rd day and dose dependent manner after 7th day. By means of vascularization, sildenafil citrate increased vascularity starting from 3rd day. The strength of acute inflammation was superior in sildenafil groups starting from 5th day; and the amount and maturation of granulation in the wound bed, as well as the strength of chronic inflammation were superior in defects treated with sildenafil citrate as early as 7th day.