Allogenic platelet gel in the treatment of pressure sores: a pilot study

Reconstructive surgery for treating pressure ulcers

BACKGROUND

There are several possible interventions for managing pressure ulcers (sometimes referred to as pressure injuries), ranging from pressure-relieving measures, such as repositioning, to reconstructive surgery. The surgical approach is usually reserved for recalcitrant wounds (where the healing process has stalled, or the wound is not responding to treatment) or wounds with full-thickness skin loss and exposure of deeper structures such as muscle fascia or bone. Reconstructive surgery commonly involves wound debridement followed by filling the wound with new tissue. Whilst this is an accepted means of ulcer management, the benefits and harms of different surgical approaches, compared with each other or with non-surgical treatments, are unclear. This is an update of a Cochrane Review published in 2016.

OBJECTIVES

To assess the effects of different types of reconstructive surgery for treating pressure ulcers (category/stage II or above), compared with no surgery or alternative reconstructive surgical approaches, in any care setting.

SEARCH METHODS

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

SELECTION CRITERIA

Published or unpublished randomised controlled trials (RCTs) that assessed reconstructive surgery in the treatment of pressure ulcers.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies, extracted study data, assessed the risk of bias and undertook GRADE assessments. We would have involved a third review author in case of disagreement.

MAIN RESULTS

We identified one RCT conducted in a hospital setting in the USA. It enrolled 20 participants aged between 20 and 70 years with stage IV ischial or sacral pressure ulcers (involving full-thickness skin and tissue loss). The study compared two reconstructive techniques for stage IV pressure ulcers: conventional flap surgery and cone of pressure flap surgery, in which a large portion of the flap tip is de-epithelialised and deeply inset to obliterate dead space. There were no clear data for any of our outcomes, although we extracted some information on complete wound healing, wound dehiscence, pressure ulcer recurrence and wound infection. We graded the evidence for these outcomes as very low-certainty. The study provided no data for any other outcomes.

AUTHORS' CONCLUSIONS

Currently there is very little randomised evidence on the role of reconstructive surgery in pressure ulcer management, although it is considered a priority area. More rigorous and robust research is needed to explore this intervention.

The role of allogeneic platelet-rich plasma in patients with diabetic foot ulcer: Current perspectives and future challenges

The frequency of chronic cutaneous wounds are sharply increasing in aging populations. Patients with age-related diseases, such as diabetes, tumors, renal failure and stroke are prone to soft tissue and skin injury, compounded by slowed healing in aging. Imbalance of wound inflammation, loss of growth factor secretion, and impairment of tissue repair abilities are all possible reasons for failed healing. Therefore, it is vital to explore novel approaches to accelerate wound healing. Platelet-rich plasma (PRP) as a cell therapy has been widely applied for tissue repair and regeneration. PRP promotes wound healing by releasing antimicrobial peptides, growth factors and micro-RNAs. Medical evidence indicates that autologous platelet-rich plasma (au-PRP) can promote wound healing effectively, safely and rapidly. However, its clinical application is usually restricted to patients with chronic cutaneous wounds, generally because of other severe complications and poor clinical comorbidities. Allogeneic platelet-rich plasma (al-PRP), with abundant sources, has demonstrated its superiority in the field of chronic wound treatment. Al-PRP could overcome the limitations of au-PRP and has promising prospects in clinical applications. The aim of this review is to summarize the current status and future challenges of al-PRP in chronic cutaneous wound management. We also summarized clinical cases to further describe the application of al-PRP for chronic wounds in clinical practice.

Platelet-derived growth factors from a single donor by apheresis and one freeze-thaw cycle for treating medication-related osteonecrosis of the jaw

Aim: To assess whether the use of allogeneic platelet-derived growth factors could serve as a feasible, effective and safe biological therapy for the treatment of medication-related osteonecrosis of the jaw (MRONJ). Materials & methods: Patients with multiple myeloma and MRONJ were included and treated with allogeneic platelet-rich plasma, continued for between 6 and 18 weeks (mean: 9). Results: We observed a treatment success rate of 87.5% (p < 0.05). Assessing the association between healing and treatment duration, we observed a statistically significant relationship (χ² = 8.00; p = 0.018; Cramer's V = 1), confirming that healing was very closely related to the duration of the treatment. Conclusion: Allogeneic platelet-rich plasma could be a recommended treatment for MRONJ. Future research with a large sample to validate our findings is required.

"Platelet-Rich Fibrin Membrane-as a novel biomaterial for pressure injury healing in a person with spinal cord injury: A case report"

INTRODUCTION

Pressure injury (PI) impacts the quality of life, and socioeconomic and psychological well-being negatively in persons with Spinal Cord Injury (SCI). Autologous Platelet Rich Plasma (PRP) and Platelet Rich Fibrin (PRF) showed promising roles in wound healing. PRF is considered a second-generation PRP, contains more growth factors and is more biocompatible than PRP. It possesses an additional favourable impact on wound healing due to its three-dimensional fibrin architecture, and antimicrobial property. There are no studies on PRF membrane use for PI healing in SCI.

CASE PRESENTATION

A 25-year-old male with operated traumatic T10 American Spinal Injury Association Impairment Scale grade A paraplegia with neurogenic bowel, and bladder and a stage II PI over the left greater trochanter, was admitted for inpatient rehabilitation. The chronic non-healing PI which did not show any improvement following normal saline (0.9%) dressing for the past 3 months, was treated with autologous PRF membrane weekly for four weeks. The PI healed completely and no adverse events were noted. Weekly total scores of the Spinal Cord Impairment Pressure Ulcer Monitoring Tool and Pressure Ulcer Scale for Healing were 6, 6, 5, 2, 0 and 12, 10, 10, 3, and 0 respectively.

DISCUSSION

To the best of our knowledge, this is the first case report on the healing of PI in SCI with the use of PRF. This novel biomaterial is a safe and effective promising agent for PI management in SCI. But further randomized trials are needed to establish stronger evidence regarding feasibility and effectiveness.

Healing of Chronic Wounds with Platelet-Derived Growth Factors from Single Donor Platelet-Rich Plasma following One Freeze-Thaw Cycle. A Cross-Sectional Study

Chronic non-healing wounds (CNHWs) may be associated with trauma or idiopathic in nature and are difficult to treat. Our objective was to assess the use of platelet-derived growth factor (PDGF) from single-donor platelets (al-PRP), using one freeze-thaw cycle, for treating CNHWs. We conducted a cross-sectional study. A total of 23 CNHWs being treated with al-PRP. The al-PRP treatment can be considered successful in well over half (n = 13, 56.5%) of the wounds. We found that all the wounds treated for up to 7 weeks showed partial or complete healing, while those treated for between 8 and 12 weeks did not show healing, healing again being successful in cases in which treatment was extended to more than 13 weeks (85.7%). Using chi-square tests, this relationship was found to be highly significant (p < 0.001, chi² = 19.51; p value = 0.00006). Notably, Cramer's V coefficient was very high (0.921), indicating that the effect size of PRP treatment duration on healing is very large (84.8%). We could suggest that the use of al-PRP in the healing of CNHWs is a promising approach. Further studies with larger sample sizes and long follow-ups are needed to obtain multivariate models to explain which factors favour the healing of ulcers treated with PRP.

A platelet-derived hydrogel improves neovascularisation in full thickness wounds

Platelets are a reservoir of growth factors, cytokines and chemokines involved in spontaneous wound repair. In this study, a platelet-rich and fibrin-rich hydrogel was generated from expired platelet components that would have otherwise been transfused. The material contained physiological concentrations of transforming growth factor β1 (TGF-β1, platelet-derived growth factor AB (PDGF-AB), PDGF-BB, insulin-like growth factor-1 (IGF-1), fibroblast growth factor 2 (FGF-2), and epidermal growth factor (EGF). The effect of the hydrogel on wound repair was investigated in SKH-1 mice. Full thickness dorsal wounds were created on the mice and treated with the hydrogel at various concentrations. Immunohistochemical staining with CD31 (endothelial cell marker) revealed that wounds treated with the hydrogel showed significantly enhanced vascularisation in the wound bed. Moreover, high levels of interleukin-6 (IL-6) and KC (IL-8 functional homologue) in treated wounds were sustained over a longer period of time, compared to untreated wounds. We postulate that sustained IL-6 is a driver, at least partly, of enhanced vascularisation in full thickness wounds treated with the hydrogel. Future work is needed to explore whether this hydrogel can be utilised as a treatment option when vascularisation is a critical limitation. STATEMENT OF SIGNIFICANCE: The economic cost of wound repair is estimated in billions of dollars each year. In many cases time required to vascularise wounds is a major contributor to slow wound repair. In this study, we developed a blood-derived platelet- and fibrin-rich hydrogel. It contains a number of growth factors actively involved in spontaneous wound healing. This hydrogel significantly improved dermal repair and vascularisation in a full-thickness wound mouse model. This study provides an action mechanism for modulation of localised inflammation.

Efficacy of Local Autologous Platelet-Rich Plasma in the Treatment of Pressure Ulcer in Spinal Cord Injury Patients

BACKGROUND

Pressure ulcer is one of the common complications occurring in spinal cord injury (SCI) patients. Platelet-rich plasma (PRP) has been found useful in the treatment of pressure ulcers in few studies. The purpose of this study was to evaluate the role of PRP in pressure ulcer healing in comparison to hydrogel dressing in SCI patients.

METHODS

In this randomized interventional study, 52 patients of SCI having pressure ulcers of grade III/IV were randomized into two groups of 26 each. In group A patients, hydrogel dressing was done while freshly prepared PRP was used in patients of group B. Pressure ulcers were evaluated at baseline and after three weeks and six weeks in terms of ulcer surface area, volume, Pressure Ulcer Scale for Healing (PUSH) score, histopathology, and ulcer healing parameters. Data were collected and quantitative variables were compared using unpaired t-test or Mann-Whitney test between the two groups and qualitative variables were compared using the chi-square test or Fisher's exact test. A p-value of <0.05 was considered statistically significant.

RESULTS

 Baseline characteristics were comparable in both groups. There was a significant improvement in ulcers in terms of surface area, volume, and PUSH score in both the groups but it was comparable (p-value >0.05). There was a significant improvement in the PRP group as compared to the other group in terms of epithelization, granulation, and neovascularization at three and six-week follow-up.

CONCLUSIONS

This study suggests that PRP is a possible and better alternative to conventional dressing methods for the treatment of pressure ulcers.

Comparison of Allogeneic Platelet-rich Plasma With Autologous Platelet-rich Plasma for the Treatment of Diabetic Lower Extremity Ulcers

Autologous platelet-rich plasma (au-PRP) has been widely used for the management of refractory chronic wounds. However, patients with diabetic lower extremity ulcers (DLEUs) usually have complicated clinical conditions, and the utility of au-PRP is limited. In this study, the feasibility, effectiveness, and safety of allogeneic platelet-rich plasma (al-PRP) and au-PRP were investigated and compared in the treatment of DLEUs. A total of 75 in-patients with type 2 diabetes were assigned to the al-PRP group (n = 20), au-PRP group (n = 25), and conventional wound therapeutic (CWT) group (n = 30) matched by the ankle brachial index and ulcer size from December 2015 to August 2018. Based on metabolic and nutritional regulation, infective control, and topical wound management, al-PRP, au-PRP, and CWT were administered to each group, respectively. Evaluation of treatment outcomes was determined by the parameters of wound healing and adverse reactions. The therapeutic times and average concentration of platelets were not significantly different between the au-PRP and al-PRP groups. The wound healing times of the al-PRP group (56.9 ± 29.22 d) and au-PRP group (55.6 ± 33.8 d) were significantly shorter than those of the CWT group (88.0 ± 43.4 d) (P < 0.01), but there was no significant difference between the groups with PRP treatment. Although there was no significant difference in the daily healing area among all groups (P > 0.05), the trend of the healing rate in the al-PRP group (16.77 ± 12.85 mm²), au-PRP group (14.31 ± 18.28 mm²), and CWT group (9.90 ± 8.51 mm²) gradually decreased. No obvious adverse reactions (fever, edema, pain, skin itching, rash, or other sensory abnormalities) were observed in either the au-PRP or the al-PRP groups. Both al-PRP and au-PRP could effectively and safely promote wound healing in patients with DLEUs. Alternatively, al-PRP could be used for DLEUs as an off-the-shelf solution when au-PRP is limited.

Cellular Response to Individual Components of the Platelet Concentrate

Platelet concentrates and especially their further product platelet lysate, are widely used as a replacement for cell culturing. Platelets contain a broad spectrum of growth factors and bioactive molecules that affect cellular fate. However, the cellular response to individual components of the human platelet concentrate is still unclear. The aim of this study was to observe cellular behavior according to the individual components of platelet concentrates. The bioactive molecule content was determined. The cells were supplemented with a medium containing 8% (v/v) of platelet proteins in plasma, pure platelet proteins in deionized water, and pure plasma. The results showed a higher concentration of fibrinogen, albumin, insulin growth factor I (IGF-1), keratinocyte growth factor (KGF), and hepatocyte growth factor (HGF), in the groups containing plasma. On the other hand, chemokine RANTES and platelet-derived growth factor bb (PDGF-bb), were higher in the groups containing platelet proteins. The groups containing both plasma and plasma proteins showed the most pronounced proliferation and viability of mesenchymal stem cells and fibroblasts. The platelet proteins alone were not sufficient to provide optimal cell growth and viability. A synergic effect of platelet proteins and plasma was observed. The data indicated the importance of plasma in platelet lysate for cell growth.

Platelet Rich Plasma Enhancement of Skin Regeneration in an ex-vivo Human Experimental Model

This study reports on the development of an original, ex-vivo wounded skin culture protocol using autologous Platelet Rich Plasma (PRP) and enriched Dulbecco's Modified Eagle's Medium (DMEM). Human skin samples obtained from specimens harvested during reduction mammoplasty procedures, were injured in their central portion—to create a standard wound—and cultured under three different conditions:

– enriched DMEM with saline solution in the central wound (control)

– enriched DMEM with the same medium in the central wound

– enriched DMEM plus 2.5% autologous PRP, with the same PRP added medium in the central wound.

Morphological analysis was carried out at 0 h (T₀) and on days 1, 3, 5 and 10 (T₁-T₃-T₅-T₁₀) using Hematoxylin and Eosin; Masson's trichrome staining; Weigert staining and Ki-67 staining to identify the skin histological features in the different experimental conditions. The combination of DMEM and PRP allowed a favorable modulation of the epithelial cells and fibroblasts proliferation, and a relevant anti-inflammatory action. PRP also demonstrated an inhibitory effect on both the collagen and elastic fibers' de-structuration and a favorable modulation of the re-organization of these fibers. The step by step histological and immune-histo-chemical regenerative effects of PRP on human skin wound repair and regeneration process was observed over a period of 10 days.

Effectiveness of Different Topical Treatments in the Healing of Pressure Injuries: A Network Meta-analysis

OBJECTIVES

Pressure injuries (PIs) are one of the most common types of complex wounds and impose a huge economic burden on the healthcare system and the patients. A plethora of topical treatments is widely available for PI treatment, yet there is a paucity of evidence with regard to the most effective treatment. The objective of this study was to compare the effect of various topical treatments and identify the best treatment choice(s) for PI healing.

DESIGN

Systematic review and network meta-analysis.

SETTING AND PARTICIPANTS

All published randomized controlled trials that compared the effectiveness of 2 or more of the following dressing groups: basic, foam, active, hydroactive, and other wound dressings.

MEASURES

The outcome was the relative risk (RR) of complete healing following treatment and the generalized pairwise modeling framework was used to generate mixed treatment effects against hydroactive wound dressing, currently the standard of treatment for PIs. All treatments were then ranked by their point estimates.

RESULTS

40 studies (1757 participants) comparing 5 dressing groups were included in the analysis. All dressings groups ranked better than basic (ie, saline gauze or similar inert dressing). The foam [RR 1.18; 95% confidence interval (CI) 0.95-1.48] and active wound dressing (RR 1.16; 95% CI 0.92-1.47) ranked better than hydroactive wound dressing in terms of healing of PIs when the latter was used as the reference group.

CONCLUSIONS/IMPLICATIONS

There was substantial uncertainty around the point estimates; however, evidence from our analysis supports the use of hydroactive wound dressings to replace basic dressings. Foam and active wound dressing groups seem promising and therefore need further investigation. High-quality, rigorously conducted research about the clinical effectiveness of the topical treatments in these 2 groups developed in consultation with health professionals, patients, and their carers is needed to identify if indeed foam and active wound dressings provide advantages over hydroactive dressings.

Dressings and topical agents for treating pressure ulcers

BACKGROUND

Pressure ulcers, also known as bedsores, decubitus ulcers and pressure injuries, are localised areas of injury to the skin or the underlying tissue, or both. Dressings are widely used to treat pressure ulcers and promote healing, and there are many options to choose from including alginate, hydrocolloid and protease-modulating dressings. Topical agents have also been used as alternatives to dressings in order to promote healing.A clear and current overview of all the evidence is required to facilitate decision-making regarding the use of dressings or topical agents for the treatment of pressure ulcers. Such a review would ideally help people with pressure ulcers and health professionals assess the best treatment options. 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 dressings and topical agents for healing pressure ulcers in any care setting. We aimed to examine this evidence base as a whole, determining probabilities that each treatment is the best, with full assessment of uncertainty and evidence quality.

SEARCH METHODS

In July 2016 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 searched clinical trials registries for ongoing and unpublished studies, and 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.

SELECTION CRITERIA

Published or unpublished randomised controlled trials (RCTs) comparing the effects of at least one of the following interventions with any other intervention in the treatment of pressure ulcers (Stage 2 or above): any dressing, or any topical agent applied directly to an open pressure ulcer and left in situ. We excluded from this review dressings attached to external devices such as negative pressure wound therapies, skin grafts, growth factor treatments, platelet gels and larval therapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment and data extraction. We conducted network meta-analysis using frequentist mega-regression methods for the efficacy outcome, probability of complete healing. We modelled the relative effectiveness of any two treatments as a function of each treatment relative to the reference treatment (saline gauze). We assumed that treatment effects were similar within dressings classes (e.g. hydrocolloid, foam). We present estimates of effect with their 95% confidence intervals for individual treatments compared with every other, 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 51 studies (2947 participants) in this review and carried out NMA in a network of linked interventions for the sole outcome of probability of complete healing. The network included 21 different interventions (13 dressings, 6 topical agents and 2 supplementary linking interventions) and was informed by 39 studies in 2127 participants, of whom 783 had completely healed wounds.We judged the network to be sparse: overall, there were relatively few participants, with few events, both for the number of interventions and the number of mixed treatment contrasts; most studies were small or very small. The consequence of this sparseness is high imprecision in the evidence, and this, coupled with the (mainly) high risk of bias in the studies informing the network, means that we judged the vast majority of the evidence to be of low or very low certainty. We have no confidence in the findings regarding the rank order of interventions in this review (very low-certainty evidence), but we report here a summary of results for some comparisons of interventions compared with saline gauze. We present here only the findings from evidence which we did not consider to be very low certainty, but these reported results should still be interpreted in the context of the very low certainty of the network as a whole.It is not clear whether regimens involving protease-modulating dressings increase the probability of pressure ulcer healing compared with saline gauze (risk ratio (RR) 1.65, 95% confidence interval (CI) 0.92 to 2.94) (moderate-certainty evidence: low risk of bias, downgraded for imprecision). This risk ratio of 1.65 corresponds to an absolute difference of 102 more people healed with protease modulating dressings per 1000 people treated than with saline gauze alone (95% CI 13 fewer to 302 more). It is unclear whether the following interventions increase the probability of healing compared with saline gauze (low-certainty evidence): collagenase ointment (RR 2.12, 95% CI 1.06 to 4.22); foam dressings (RR 1.52, 95% CI 1.03 to 2.26); basic wound contact dressings (RR 1.30, 95% CI 0.65 to 2.58) and polyvinylpyrrolidone plus zinc oxide (RR 1.31, 95% CI 0.37 to 4.62); the latter two interventions both had confidence intervals consistent with both a clinically important benefit and a clinically important harm, and the former two interventions each had high risk of bias as well as imprecision.

AUTHORS' CONCLUSIONS

A network meta-analysis (NMA) of data from 39 studies (evaluating 21 dressings and topical agents for pressure ulcers) is sparse and the evidence is of low or very low certainty (due mainly to risk of bias and imprecision). Consequently we are unable to determine which dressings or topical agents are the most likely to heal pressure ulcers, and it is generally unclear whether the treatments examined are more effective than saline gauze.More research is needed to determine whether particular dressings or topical agents improve the probability of healing of pressure ulcers. The NMA is uninformative regarding which interventions might best be included in a large trial, and it may be that research is directed towards prevention, leaving clinicians to decide which treatment to use on the basis of wound symptoms, clinical experience, patient preference and cost.

ALLOGENEIC PLATELET-RICH PLASMA FOR ROTATOR CUFF REPAIR

OBJECTIVE

To investigate the safety and efficacy of allogeneic platelet-rich plasma (PRP) in rotator cuff repair .

METHODS

Seventeen patients with a full-thickness rotator cuff tear were included. Ten patients underwent arthroscopic rotator cuff repair with allogeneic, and seven patients with autologous PRP. Three PRP gels in a volume 3 ml each were applied between the torn end and the greater tuberosity. Clinical outcomes were assessed preoperatively and at a minimum of 2 years after surgery. Structural outcomes were evaluated with the presence of retear and the change of the cross-sectional area (ACT) of the supraspinatus .

RESULTS

Allogeneic PRP did not cause any adverse events during the follow-up period. There was no significant difference in the clinical outcome measures between the two groups (all p > 0.05). The retear rate was 33.3% and 25.0% in the allogeneic group and autologous group, respectively (p = 0.764). The change between the one-year postoperative and immediately postoperative ACT was not also significantly different between the two groups (p = 0.373) .

CONCLUSION

Allogeneic PRP in arthroscopic rotator cuff did not cause any local or general complications and that has the efficacy comparable to autologous PRP with respect to the clinical and structural outcomes. Level of Evidence III, Retrospective Comparative Study.

Reconstructive surgery for treating pressure ulcers

BACKGROUND

The management of pressure ulcers involves several interventions ranging from pressure-relieving measures such as repositioning, to treatments that can include reconstructive surgery. Such surgery may be considered for recalcitrant wounds when full thickness skin loss arises and deeper structures such as muscle fascia and even bone are exposed. The surgery commonly involves wound debridement followed by the addition of new tissue into the wound. Whilst reconstructive surgery is an accepted means of ulcer management, the benefits and harms of surgery compared with non-surgical treatments, or alternative surgical approaches are not clear.

OBJECTIVES

To assess the effects of reconstructive surgery for healing pressure ulcers (stage II or above), comparing surgery with no surgery or comparing alternative forms of surgery in any care setting.

SEARCH METHODS

We searched the following electronic databases to identify reports of relevant randomised clinical trials (searched 26 September 2016): the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL. We also searched three clinical trials registers and reference lists of relevant systematic reviews, meta-analyses and health technology assessment reports.

SELECTION CRITERIA

Published or unpublished randomised controlled trials that assessed reconstructive surgery in the treatment of pressure ulcers.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection. We planned that two review authors would also assess the risk of bias and extract study data.

MAIN RESULTS

We did not identify any studies that met the review eligibility criteria nor any registered studies investigating the role of reconstructive surgery in the management of pressure ulcers.

AUTHORS' CONCLUSIONS

Currently there is no randomised evidence that supports or refutes the role of reconstructive surgery in pressure ulcer management. This is a priority area and there is a need to explore this intervention with more rigorous and robust research.

Autologous platelet-rich plasma for treating chronic wounds

BACKGROUND

Autologous platelet-rich plasma (PRP) is a treatment that contains fibrin and high concentrations of growth factors with the potential to improve the healing of chronic wounds. This is the first update of a review first published in 2012.

OBJECTIVES

To determine whether autologous PRP promotes the healing of chronic wounds.

SEARCH METHODS

In June 2015, for this first update, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library): Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We also searched for ongoing and unpublished clinical trials in the WHO International Clinical Trials Registry Platform (ICTRP) (searched January 2015). We did not impose any restrictions with respect to language, date of publication, or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared autologous PRP with placebo or alternative treatments for any type of chronic wound in adults. We did not apply any date or language restrictions.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology, including two reviewers independently selecting studies for inclusion, extracting data, and assessing risk of bias.

MAIN RESULTS

The search identified one new RCT, making a total of 10 included RCTs (442 participants, 42% women). The median number of participants per RCT was 29 (range 10 to 117). Four RCTs recruited people with a range of chronic wounds; three RCTs recruited people with venous leg ulcers, and three RCTs considered foot ulcers in people with diabetes. The median length of treatment was 12 weeks (range 8 to 40 weeks).It is unclear whether autologous PRP improves the healing of chronic wounds generally compared with standard treatment (with or without placebo) (risk ratio (RR) 1.19, 95% confidence interval (CI) 0.95 to 1.50; I(2) = 27%, low quality evidence, 8 RCTs, 391 participants). Autologous PRP may increase the healing of foot ulcers in people with diabetes compared with standard care (with or without placebo) (RR 1.22, 95% CI 1.01 to 1.49; I(2) = 0%, low quality evidence, 2 RCTs, 189 participants). It is unclear if autologous PRP affects the healing of venous leg ulcers (RR 1.02, 95% CI 0.81 to 1.27; I(2) = 0% ). It is unclear if there is a difference in the risk of adverse events in people treated with PRP or standard care (RR 1.05, 95% CI 0.29 to 3.88; I(2) = 0%, low quality evidence from 3 trials, 102 participants).

AUTHORS' CONCLUSIONS

PRP may improve the healing of foot ulcers associated with diabetes, but this conclusion is based on low quality evidence from two small RCTs. It is unclear whether PRP influences the healing of other chronic wounds. The overall quality of evidence of autologous PRP for treating chronic wounds is low. There are very few RCTs evaluating PRP, they are underpowered to detect treatment effects, if they exist, and are generally at high or unclear risk of bias. Well designed and adequately powered clinical trials are needed.

Treatment of pressure ulcers: a clinical practice guideline from the American College of Physicians

DESCRIPTION

The American College of Physicians (ACP) developed this guideline to present the evidence and provide clinical recommendations based on the comparative effectiveness of treatments of pressure ulcers.

METHODS

This guideline is based on published literature on this topic that was identified by using MEDLINE, EMBASE, CINAHL, EBM Reviews, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, and the Health Technology Assessment database through February 2014. Searches were limited to English-language publications. The outcomes evaluated for this guideline include complete wound healing, wound size (surface area, volume, and depth) reduction, pain, prevention of sepsis, prevention of osteomyelitis, recurrence rate, and harms of treatment (including but not limited to pain, dermatologic complications, bleeding, and infection). This guideline grades the quality of evidence and strength of recommendations by using ACP's clinical practice guidelines grading system. The target audience for this guideline includes all clinicians, and the target patient population is patients with pressure ulcers.

RECOMMENDATION 1

ACP recommends that clinicians use protein or amino acid supplementation in patients with pressure ulcers to reduce wound size. (Grade: weak recommendation, low-quality evidence).

RECOMMENDATION 2

ACP recommends that clinicians use hydrocolloid or foam dressings in patients with pressure ulcers to reduce wound size. (Grade: weak recommendation, low-quality evidence).

RECOMMENDATION 3

ACP recommends that clinicians use electrical stimulation as adjunctive therapy in patients with pressure ulcers to accelerate wound healing. (Grade: weak recommendation, moderate-quality evidence).

The Lipid Portion of Activated Platelet-Rich Plasma Significantly Contributes to Its Wound Healing Properties

Objective: Platelet-rich plasma (PRP) is a popular choice for the treatment of chronic wounds. Current dogma attributes these healing properties to the peptide growth factors of PRP. However, PRP is also rich in bioactive lipids whose contribution to healing has not been characterized and warrants investigation due to the protease-rich environment of chronic wounds. Approach: The lipid fraction of PRP was tested with respect to proliferation and migration of primary adult human dermal fibroblasts (HDFa)±exposure to chronic wound fluid (CWF). This fraction was also characterized via LC-MS/MS for bioactive lipids. A synthetic formulation of the bioactive lipid composition was developed and tested for the ability to overcome proliferative growth arrest induced by CWF. Results: The data demonstrate the ability of the lipid fraction of PRP to significantly enhance the migration and proliferation of HDFa, and to overcome the proliferative growth arrest induced by CWF. Furthermore, the synthetic lipid formulation generated following characterization of the PRP lipidome demonstrated a similar ability to overcome proliferative arrest of HDFa in the presence of CWF. Innovation: For the first time, we demonstrate the relevance of the lipid fraction of PRP toward the biology of wound healing. These studies open the possibility of altering the lipid profile of PRP via diet or exogenous pathway manipulation to obtain a better healing outcome. Conclusion: The lipid fraction of PRP is under investigated and yet relevant component in wound healing. The current study demonstrates the relevance of this fraction in wound healing by PRP.

To Evaluate Antimicrobial Properties of Platelet Rich Plasma and Source of Colonization in Pressure Ulcers in Spinal Injury Patients

Background. Exposure of pressure ulcers (PrUs), particularly to urine and feces, leads to increased colonization of wounds. The aim of the present study was to evaluate the source of microbial colonization and antimicrobial properties of autologous platelet rich plasma (PRP) in controlling it in PrUs. Methods. Twenty-five patients of spinal cord injury (SCI) with at least two PrUs were taken for the study. Local application of autologous PRP on one PrU (case) was compared with saline dressing on the other PrU (control). Urine cultures, urethral meatus, PrUs, and perineal swabs were taken at weekly interval for five weeks. Result. Colonization rate of PrUs (case) decreased from 92% at enrollment to 24% at the 5th week but did not significantly decrease in PrUs (control) from enrollment (84%) to the 5th week (76%). Association between PrU (case) and perineal cultures was observed for Staphylococcus aureus at enrollment 41% (χ2=6.76, P<0.01) and at the 2nd week 47% (χ2=5.83, P<0.05). 47% association between PrU (control) and perineal cultures at enrollment (χ2=4.11, P<0.05) and 29% association at the 2nd week (χ2=8.41, P<0.01) were observed for Staphylococcus aureus. There was association between bacteria present in perineum/urine and those colonizing PrUs. Conclusion. There is a significant association between PrUs colonization and bacteria present in local environment (urine and feces). Local application of autologous PRP changes the “biological milieu” of the PrUs through its antimicrobial properties leading to reduction in bacterial colonization.

Platelet derivatives in regenerative medicine: an update

Prior preclinical and clinical studies support the use of platelet-derived products for the treatment of soft and hard tissue lesions. These regenerative effects are controlled by autocrine and paracrine biomolecules including growth factors and cytokines contained in platelet alpha granules. Each growth factor is involved in a phase of the healing process, such as inflammation, collagen synthesis, tissue granulation, and angiogenesis collectively promoting tissue restitution. Platelet derivatives have been prepared as platelet-rich plasma, platelet gel, platelet-rich fibrin, and platelet eye drops. These products vary in their structure, growth factors, composition, and cytokine concentrations. Here, we review the current use of platelet-derived biological products focusing on the rationale for their use and the main requirements for their preparation. Variation in the apparent therapeutic efficacy may have resulted from a lack of reproducible, standardized protocols for preparation. Despite several individual studies showing favorable treatment effects, some randomized controlled trials as well as meta-analyses have found no constant clinical benefit from the application of platelet-derived products for prevention of tissue lesions. Recently, 3 published studies in dentistry showed an improvement in bone density. Seven published studies showed positive results in joint regeneration. Five published studies demonstrated an improvement in the wound healing, and an improvement of eye epithelial healing was observed in 2 reports. Currently, at least 14 ongoing clinical trials in phase 3 or 4 have been designed with large groups of treated patients (n > 100). Because the rationale of the therapy with platelet-derived compounds is still debated, a definitive insight can be acquired only when these large randomized trials will be completed.

The influence of platelet-rich plasma on myogenic differentiation

The ability to expand and direct both precursor and stem cells towards a differential fate is considered extremely advantageous in tissue engineering. Platelet-rich plasma (PRP) possesses a milieu of growth factors and cytokines, which have the potential to have either a differentiative or proliferative influence on the cell type tested. Here, we investigated the effect of PRP on C2C12 myoblasts. A range of PRP concentrations in differentiation media was used to determine whether a concentration dependence existed, while PRP embedded in fibres of aligned electrospun polydioxanone and polycaprolactone was used to determine whether this presence of fibres would cause any differences in response. In both cases, it was found that late myogenic markers were suppressed after 7 days in culture. However, an early differentiation marker, MyoD, was upregulated during this same time period. The results from this study represent the ability of PRP to have an influence over both myogenic proliferation and differentiation, a factor which could prove useful in future studies involved with skeletal muscle tissue engineering.

Chitosan stabilizes platelet growth factors and modulates stem cell differentiation toward tissue regeneration

The idea of using chitosan as a functional delivery aid to support simultaneously PRP, stem cells and growth factors (GF) is associated with the intention to use morphogenic biomaterials to modulate the natural healing sequence in bone and other tissues. For example, chitosan-chondroitin sulfate loaded with platelet lysate was included in a poly(D,L-lactate) foam that was then seeded with human adipose-derived stem cells and cultured in vitro under osteogenic stimulus: the platelet lysate provided to the bone tissue the most suitable assortment of GF which induces the osteogenic differentiation of the mesenchymal stem cells. PDGF, FGF, IGF and TGF-β were protagonists in the repair of callus fractures. The release of GF from the composites of chitosan-PRP and either nano-hydroxyapatite or tricalcium phosphate was highly beneficial for enhancing MSC proliferation and differentiation, thus qualifying chitosan as an excellent vehicle. A number of biochemical characteristics of chitosan exert synergism with stem cells in the regeneration of soft tissues.

A preliminary study on the potential of manuka honey and platelet-rich plasma in wound healing

Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey, and a combination of PRGF and MH. Results. All three cell types demonstrated increases in cellular activity in the presence of PRGF, with further increases in activity seen in the presence of PRGF+MH. hDFs proved to be the most positively responsive cells, as they experienced enhanced proliferation, collagen matrix production, and migration into an in vitro wound healing model with the PRGF+MH-supplemented media. Conclusion. This preliminary in vitro study is the first to evaluate the combination of PRGF and Manuka honey, two products with the potential to increase regeneration individually, as a combined product to enhance dermal regeneration.

Autologous platelet-rich plasma for treating chronic wounds

BACKGROUND

Autologous platelet-rich plasma (PRP) is a treatment that contains fibrin and high concentrations of growth factors and has the potential to aid wound healing.

OBJECTIVES

To determine whether autologous PRP promotes the healing of chronic wounds.

SEARCH METHODS

We searched the Cochrane Wounds Group Specialised Register (searched 15 August 2012); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 8); Ovid MEDLINE (1950 to August Week 1 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, August 14, 2012); Ovid EMBASE (1980 to 2012 Week 32); EBSCO CINAHL (1982 to 10 August 2012) and International Clinical Trials Registry Platform (ICTRP)(accessed 22 August 2012). No date or language restrictions were applied.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared autologous PRP with placebo or alternative treatments for any type of chronic wound in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed each study against the inclusion criteria, extracted data and assessed risk of bias for all included trials. We calculated the risk ratio (RR) or the mean difference (MD) and time to wound healing was analysed as survival data using the hazard ratio (HR). We considered heterogeneity as significant when I(2) was >75%.

MAIN RESULTS

Nine eligible RCTs were included, with a total of 325 participants of whom 44% were women. The median number of participants per RCT was 26 (range 10 to 86). Four RCTs recruited people with mixed chronic wounds (there were participants with wounds caused by more than one aetiology and participants who had wounds of several aetiologies in the same trial), three RCTs recruited people with venous leg ulcers and two RCTs considered foot ulcers in people with diabetes. The median length of treatment was 12 weeks (range eight to 40 weeks).One study was at low risk of bias, three studies were at high risk of bias with the remainder being at overall unclear risk of bias. The proportion of completely healed chronic wounds was reported in seven RCTs that compared PRP with standard treatment or placebo, with no statistically significant difference between the groups, in diabetic foot ulcers (RR 1.16; 95% CI 0.57 to 2.35), in venous leg ulcers (pooled RR 1.02; 95% CI 0.81 to 1.27; I(2)=0% ) and in mixed chronic wounds (pooled RR 1.85; 95% CI 0.76 to 4.51; I(2)=42%). The total area epithelialised at the end of the intervention was reported in three RCTs of mixed chronic wounds, there was no statistically significant difference between the groups (pooled MD -1.94 cm(2); 95% CI -4.74 to 0.86; I(2)=47%). The percentage of wound area healed was reported in two RCTs of mixed chronic wounds, and results were statistically significant in favour of the PRP group (RR 51.78%; 95% CI 32.70 to 70.86; I(2)= 0%). Wound complications like infection or necrosis were reported by three RCTs, and there was no statistically significant difference between groups (RR 1.08; 95% CI 0.31 to 3.73). Adverse effects were reported by three studies and there was no statistically significant difference between people treated with PRP and those not given PRP (pooled RR 1.07; 95% CI 0.32 to 3.58; I(2)=0%).

AUTHORS' CONCLUSIONS

There is currently no evidence to suggest that autologous PRP is of value for treating chronic wounds. However, current evidence is based on a small number of RCTs, most of which are either at high or unclear risk of bias. Well-designed and adequately powered clinical trials are needed.

Combined use of super-oxidised solution with negative pressure for the treatment of pressure ulcers: case report

A 61-year-old patient was affected by flaccid paraplegia for 20 years because of post-traumatic medullar injury caused by an accidental fall, with stage IV sacral pressure ulcer for 3 years. The patient later developed stage IV sacral pressure ulcer. After 6 months, a new granulation tissue formation appeared in the wound and a reduction of its diameter was observed (length 20 cm, width 15 cm, depth 5 cm). We therefore treated the wound with PRP (platelet rich plasma) intra-lesion and peri-lesional injections. The wounds were covered with three-dimensional polymerised hyaluronic acid medicated biologic dressing. After the surgery, a moderate reduction in diameter and the depth was observed. Super-oxidised solution (SOS-Dermacyn) was applied to control infection locally together with negative pressure to control the exudate and the local bacteremia, to avoid infectious complications without application of systematic antibiotic therapy.

Incorporating platelet-rich plasma into electrospun scaffolds for tissue engineering applications

Platelet-rich plasma (PRP) therapy has seen a recent spike in clinical interest due to the potential that the highly concentrated platelet solutions hold for stimulating tissue repair and regeneration. The aim of this study was to incorporate PRP into a number of electrospun materials to determine how growth factors are eluted from the structures, and what effect the presence of these factors has on enhancing electrospun scaffold bioactivity. PRP underwent a freeze-thaw-freeze process to lyse platelets, followed by lyophilization to create a powdered preparation rich in growth factors (PRGF), which was subsequently added to the electrospinning process. Release of protein from scaffolds over time was quantified, along with the quantification of human macrophage and adipose-derived stem cell (ADSC) chemotaxis and proliferation. Protein assays demonstrated a sustained release of protein from PRGF-containing scaffolds at up to 35 days in culture. Scaffold bioactivity was enhanced as ADSCs demonstrated increased proliferation in the presence of PRGF, whereas macrophages demonstrated increased chemotaxis to PRGF. In conclusion, the work performed in this study demonstrated that the incorporation of PRGF into electrospun structures has a significant positive influence on the bioactivity of the scaffolds, and may prove beneficial in a number of tissue engineering applications.

Use of platelet rich plasma gel on wound healing: a systematic review and meta-analysis

OBJECTIVE

Autologous platelet rich plasma is an advanced wound therapy used in hard-to-heal acute and chronic wounds. To better understand the use and clinical outcomes of the therapy, a systematic review of the published literature in cutaneous wounds was performed.

METHODS

Electronic and hand searches for randomized controlled trials and comparative group studies using platelet rich plasma therapy in cutaneous wounds and published over the last 10 years was conducted. Eligible studies compared the treatment to standard care or other interventions. All citations were screened and eligible studies were assessed for validity, quality, and bias using accepted scoring methods. The primary outcomes were effect of platelet rich plasma and control wound care on wound healing and related healing measurements. Secondary outcomes related to healing such as infection, pain, exudate, adverse events, and quality of life were also considered. The meta-analysis utilized appropriate statistical methods to determine the overall treatment effect on chronic and acute wound healing and infection.

RESULTS

The search terms resulted in 8577 citations and after removing duplicates and screening for protocol eligibility, a total of 24 papers were used. The meta-analysis of chronic wound studies revealed platelet rich plasma therapy is significantly favored for complete healing. The meta-analysis of acute wounds with primary closure studies demonstrated that presence of infection was reduced in platelet rich plasma treated wounds.

CONCLUSIONS

This systematic review and meta-analysis of platelet rich plasma therapy in cutaneous wounds showed complete and partial wound healing was improved compared to control wound care.

Effect of platelet-rich plasma on growth and antigenic profile of human osteoblasts and its clinical impact

PURPOSE

In recent years, there has been widespread clinical use of platelet-rich plasma (PRP) to facilitate the regeneration of different tissues. However, few data are available on the effect of PRP on parameters other than cell growth. The aim of the present study was to evaluate the effect of PRP on the cell cycle, antigenic profile, and proliferation of primary cultured human osteoblasts.

MATERIALS AND METHODS

The cells in the present study were derived from human bone sections obtained from healthy volunteers during third molar surgery. PRP was prepared from human venous blood and used to culture the cell line obtained from the same patient. Flow cytometry was used to study the cell cycle, antigenic profile, and proliferation.

RESULTS

The treatment of osteoblasts with PRP modified the expression of CD54, CD80, CD86, and HLA-DR antigens. PRP treatment increased cell proliferation in the short term, but the cell proliferation capacity diminished in the long term, perhaps owing to cell exhaustion. No change in the cell cycle profile was observed in the PRP-cultured cells.

CONCLUSIONS

These results suggest that PRP treatment accelerates bone neoformation with no cell cycle changes that might carry a risk of malignant transformation.

Effect of platelet rich plasma gel in a physiologically relevant platelet concentration on wounds in persons with spinal cord injury

The objective of the study was to investigate the use of a 1·3 times normal platelet concentration platelet-rich plasma (PRP) gel to move chronic wounds towards healing in persons with spinal cord injury (SCI). The study design was a case series of 20 persons with SCI with non healing wounds. The outcome measures were, in wound area, volume, undermining and sinus tracts/tunnels (ST/Ts), calculated average, (i) percent of change from baseline, (ii) change per day from baseline, (iii) number of treatments and (iv) number of weeks. In a mean of 4·0, after treatments over 3·4 weeks, the wounds closed on an average of 47·9% in area and 56·0% in volume. Undermining closed on an average of 31·4% using 3·5 treatments over 2·6 weeks. ST/Ts closed on an average of 26·1% after 2·3 treatments over 1·5 weeks. Clinical relevance by percent of positive responders and their response: in area, 90·0% of the subjects responded positively, the average reduction was 53·8%. In volume, 90·0% responded, with an average reduction of 67·3%. Of four subjects with undermining, 75% closed 47·0% on average. Of the three with ST/Ts, 100% closed 26·1% on average. Average haemoglobin and haematocrit levels were below normal. To conclude, 1·3× PRP gel appears to progress chronic, non healing wounds in SCI patients into the granulation phase of healing quickly. Review of the literature shows these results may not be applied to all PRP preparations.