The feasibility of negative pressure wound therapy versus standard dressings in paediatric hand and foot burns protocol: a pilot, single-centre, randomised control trial

INTRODUCTION

The goal of paediatric hand and foot burn management is hypertrophic scar and/or contracture prevention. The risk of scar formation may be minimised by integrating negative pressure wound therapy (NPWT) as an acute care adjunct as it decreases the time to re-epithelialisation. NPWT has known associated therapeutic burden; however, this burden is hypothesised to be outweighed by an increased likelihood of hypertrophic scar prevention. This study will assess the feasibility, acceptability and safety of NPWT in paediatric hand and foot burns with secondary outcomes of time to re-epithelialisation, pain, itch, cost and scar formation.

METHODS AND ANALYSIS

This is a single-site, pilot randomised control trial. Participants must be aged ≤ 16 years, otherwise well and managed within 24 h of sustaining either a hand or foot burn. Thirty participants will be randomised to either standard care (Mepitel®-a silicone wound interface contact dressing-and ACTICOAT™-a nanocrystalline silver-impregnated dressing) or standard care plus NPWT. Patients will be reviewed until 3 months post-burn wound re-epithelialisation, with measurements taken at dressing changes to assess primary and secondary outcomes. Surveys, randomisation and data storage will be done via online platforms and physical data storage collated at the Centre for Children's Health Research, Brisbane, Australia. Analysis will be performed using the Stata statistical software.

ETHICS AND DISSEMINATION

Queensland Health and Griffith University Human Research ethics approval including a site-specific assessment was obtained. The findings of this study will be disseminated through clinical meetings, conference presentations and peer reviewed journals.

TRIAL REGISTRATION

Registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12622000044729, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=381890&isReview=true , registered 17/01/2022).

[Suitability of biological acellular dermal matrices as a skin replacement]

INTRODUCTION

 Tissue defects are associated with loss of epidermal and dermal components of the skin. For full-thickness tissue defects, dermal equivalents are useful to enable rapid wound closure. Split-thickness skin grafts are associated with loss of tissue elasticity resulting in scar contractures that can impair joint mobility. Synthetic collagen matrices and allogeneic acellular dermal matrices (ADM) are commercially available and could serve as skin tissue replacement. The aim of this study was to investigate whether ADM of different dermal layers or bioartificial matrices can serve as cutaneous replacement. For this purpose, cellular migration, differentiation and the inflammatory reaction were studied in an established ex vivo skin organ model.

MATERIALS AND METHODS

 Human split-thickness skin grafts were transplanted onto ADM (Epiflex, DIZG, Berlin, Germany), de-epidermized dermis (DED) or an artificial collagen-elastin matrix (Matriderm, Dr. Suwelack, Billerbeck, Germany). Epithelial migration was studied using an established skin culture model at the air-liquid interface. In addition, the effect of tissue from different dermal compartments, e. g. papillar and reticular dermis, on epithelial migration was compared. Epithelial resurfacing and differentiation of matrices as well as the inflammatory reaction were studied using histological, immunohistochemical and biochemical analyses.

RESULTS AND CONCLUSION

 Significantly more epithelial outgrowth area was found on DED (2.54 mm ± 0.43 mm, mean ± SEM) compared to papillary ADM (1.32 mm ± 0.44 mm, p = 0.039), to reticular ADM (no horizontal growth, p < 0.0001) and collagen-elastin matrix (0.78 mm ± 0.11 mm, p = 0.0056) measured by fluorescence microscopy over 10 days presumably due to the presence of pro-migratory basement membrane residues on DED. Reepithelialization was significantly higher (p < 0.002) on papillary dermis compared to ADM of reticular origin. In contrast to the biological matrices, a complete horizontal penetration was found in the macroporous collagen-elastin matrix. Pro-inflammatory mediators varied depending on the human skin donor and matrix. In summary, the biochemical structure of the matrix' surface and its origin influenced the epithelial behaviour with regard to migration, differentiation and inflammatory response.

Strategies to prevent hypertrophic scar formation: a review of therapeutic interventions based on molecular evidence

Once scar tissues mature, it is impossible for the surrounding tissue to regenerate normal dermal tissue. Therefore, it is essential to understand the fundamental mechanisms and establish effective strategies to inhibit aberrant scar formation. Hypertrophic scar formation is considered a result of the imbalance between extracellular matrix synthesis and degradation during wound healing. However, the underlying mechanisms of hypertrophic scar development are poorly understood. The purpose of this review was to outline the management in the early stage after wound healing to prevent hypertrophic scar formation, focusing on strategies excluding therapeutic agents of internal use. Treatment aimed at molecular targets, including cytokines, will be future options to prevent and treat hypertrophic scars. More basic studies and clinical trials, including combination therapy, are required to investigate the mechanisms and prevent hypertrophic scar formation.

Abnormal expression of the vitamin D receptor in keloid scars

Keloids are abnormal fibroproliferative scars that pose a significant challenge to patients and clinicians. The molecular basis for keloid formation remains incompletely understood, and currently no universally effective treatments exist. It is well recognized that keloids are more prevalent in populations with darkly pigmented skin, such as African Americans, but the basis for the link between skin color and keloid risk is not known. Pigmentation reduces vitamin D production in the skin. Because most of the body's vitamin D is produced in the skin, rates of vitamin D deficiency are higher in populations with darker skin pigmentation. In addition to regulation of calcium homeostasis, vitamin D plays important roles in cell proliferation, differentiation, cancer progression, inflammation, and fibrosis. The activities of vitamin D are dependent on the vitamin D receptor (VDR), a member of the steroid nuclear receptor superfamily. The ligand-bound VDR acts as a transcription factor; thus, nuclear localization is required for ligand-dependent regulation of target gene expression. The current study investigated expression and nuclear localization of VDR in keloid scars (N=24) and biopsies of normal skin (N=24). Immunohistochemistry with two different antibodies demonstrated reduced VDR protein levels in a majority of keloid scars. Further, the percentage of epidermal cells displaying nuclear VDR localization was significantly lower in keloid scars compared with normal skin samples. Interestingly, analysis of VDR-positive nuclei among different normal skin samples showed a significant reduction in nuclear localization in epidermis of black donors compared with white donors. The results suggest that VDR may play a role in keloid pathology, and hint at a possible role for VDR in the increased susceptibility to keloid scarring in individuals with darkly pigmented skin.

Partial epithelial-mesenchymal transition in keloid scars: regulation of keloid keratinocyte gene expression by transforming growth factor-β1

Background

Keloids are an extreme form of abnormal scarring that result from a pathological fibroproliferative wound healing process. The molecular mechanisms driving keloid pathology remain incompletely understood, hindering development of targeted, effective therapies. Recent studies in our laboratory demonstrated that keloid keratinocytes exhibit adhesion abnormalities and display a transcriptional signature reminiscent of cells undergoing epithelial-mesenchymal transition (EMT), suggesting a role for EMT in keloid pathology. In the current study, we further define the EMT-like phenotype of keloid scars and investigate regulation of EMT-related genes in keloid.

Methods

Primary keratinocytes from keloid scar and normal skin were cultured in the presence or absence of transforming growth factor beta 1 (TGF-β1) +/− inhibitors of TGF-β1 and downstream signaling pathways. Gene expression was measured using quantitative polymerase chain reaction. Migration was analyzed using an in vitro wound healing assay. Proteins in keloid scar and normal skin sections were localized by immunohistochemistry. Statistical analyses utilized SigmaPlot (SyStat Software, San Jose, CA) or SAS^® (SAS Institute, Cary, NC).

Results

In keloid and normal keratinocytes, TGF-β1 regulated expression of EMT-related genes, including hyaluronan synthase 2, vimentin, cadherin-11, wingless-type MMTV integration site family, member 5A, frizzled 7, ADAM metallopeptidase domain 19, and interleukin-6. Inhibition of canonical TGF-β1 signaling in keloid keratinocytes significantly inhibited expression of these genes, and TGF-β1 stimulation of normal keratinocytes increased their expression. The inhibition of the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway or the p38 mitogen-activated protein kinase pathway attenuated TGF-β1-induced expression of subsets of these genes. Migration of keloid keratinocytes, previously shown to be increased compared with normal keratinocytes, was significantly reduced by inhibition of TGF-β1 or ERK1/2 signaling. Biomarkers of EMT, including reduced E-cadherin and increased active β-catenin, were observed in keloid epidermis in vivo. However, evidence of basement membrane breakdown in keloid scar was not observed.

Conclusions

The results suggest that keloid keratinocytes exist in an EMT-like metastable state, similar to activated keratinocytes in healing wounds. The EMT-like gene expression pattern of keloid keratinocytes is regulated by canonical and non-canonical TGF-β1 signaling pathways. Therefore, interventions targeting TGF-β1-regulated EMT-like gene expression in keloid keratinocytes may serve to suppress keloid scarring.

Electronic supplementary material

The online version of this article (doi:10.1186/s41038-016-0055-7) contains supplementary material, which is available to authorized users.

Increased cutaneous wound healing effect of biodegradable liposomes containing madecassoside: preparation optimization, in vitro dermal permeation, and in vivo bioevaluation

Madecassoside (MA) is highly potent in treating skin disorders such as wounds and psoriasis. However, the topical wound healing effect of MA was hampered by its poor membrane permeability. In order to overcome this shortcoming, MA liposomes were designed and prepared by a double-emulsion method to enhance transdermal and wound healing effects. In this study, response surface methodology was adopted to yield the optimal preparation conditions of MA double-emulsion liposomes with average particle size of 151 nm and encapsulation efficiency of 70.14%. Moreover, MA double-emulsion liposomes demonstrated superior stability and homogeneous appearance in 5 months; their leakage rate was <12% even at 37°C and <5% at 4°C within 1 month. In vitro skin permeation, skin distribution, and burn wound healing of MA liposomal formulations were conducted for the first time to evaluate MA delivery efficiency and wound healing effect. The transdermal property and wound cure effect of MA double-emulsion liposomes were superior to those of MA film dispersion liposomes, and both the methods were endowed with an excellent performance by polyethylene glycol modification. In conclusion, double-emulsion liposome formulation was an applicable and promising pharmaceutical preparation for enhancing MA delivery toward wound healing effect and improving wound-healing progress.

Interim pressure garment therapy (4-6 mmHg) and its effect on donor site healing in burn patients: study protocol for a randomised controlled trial

Background

Pressure garment therapy (PGT) is well accepted and commonly used by clinicians in the treatment of burns scars and grafts. The medium to high pressures (24–40 mmHg) in these garments can support scar minimisation, and evidence is well documented for this particular application. However, PGT specifically for burn donor sites, of which a sequela is also scarring, is not well documented. This study protocol investigates the impact of a low pressure (4–6 mmHg) interim garment on donor site healing and scarring. With a primary purpose of holding donor dressings in place, the application of the interim pressure garment (IPG) appears to have been twofold. IPGs for donor sites have involved inconsistent application with a focus on securing wound dressing rather than scar management. However, anecdotal and observational evidence suggests that IPGs also make a difference to some patient’s scar outcomes for donor sites. This study protocol outlines a randomised controlled trial designed to test the effectiveness of this treatment on reducing scarring to burn donor sites.

Methods/design

This study is a single-centre, single (assessor)-blinded, randomised control trial in patients with burns donor sites to their thighs. Patients will be randomly allocated to a control group (with no compression to donor sites) or to an experimental group (with compression to donor sites) as the comparative treatment. Groups will be compared at baseline regarding the important prognostic indicators: donor site location, depth, size, age, and time since graft (5 days). The IPG treatment will be administered post-operatively (on day 5). Follow-up assessments and garment replacement will be undertaken fortnightly for a period of 2 months.

Discussion

This study focuses on a unique area of burns scar management using a low-pressure tubular support garment for the reduction of donor site scars. Such therapy specifically for donor scar management is poorly represented in the literature. This study was designed to test a potentially cost-effective scar prevention for patients with donor sites to the thigh. No known studies of this nature have been carried out to date, and there is a need for rigorous clinical evidence for low-pressure support garments for donor site scar minimisation.

Trial registration

Australian New Zealand Clinical Trials Registry identifier ACTRN12610000127000. Registered 8 Mar 2010.

Management of Hypertrophic Burn Scar: A Comparison between the Efficacy of Exercise-Physiotherapy and Pressure Garment-Silicone on Hypertrophic Scar

Purpose

Our study aims to investigate the effectiveness of other treatment methods for burn related scarring and to determine the possibility of their routine administration in similar clinical settings.

Methods

Through a prospective study, 66 patients were enrolled to receive either the conventional pressure garment therapy (PGT) and Silicone (control group) or exercise and physiotherapy (case group). Patients were visited regularly to be examined for the status of their scars’ regression, limbs’ dysfunction, and joint motion. Then, these two groups were compared to determine the efficacy of exercise and physiotherapy as an alternative to the conventional treatment with PGT.

Results

After about 20 months follow-up, decreased articular range of motion (ROM) was: 16 (51.5%) cases compared to 5 (15%) of controls had mild, 11 (35.5%) of the cases compared to 13 (39.5%) of the controls had moderate; and 4 (13%) of the cases compared to 15 (45.5%) of the controls had severe decreased ROM which revealed statistically significant difference (P<0.01). At the same time, Vancouver Scar Scale score was: 15 (48%) of the cases and 6 (18%) of the controls had mild Scar Scale, 12 (39%) of the cases and 14 (42.5%) of the controls had moderate score and 4 (3%) of the cases and 13 (39.5%) of the controls had severe score which revealed a statistically significant difference (P<0.05).

Conclusion

Our study showed that physical therapy andexercise are more effective than PGT, in management of burn hypertrophic scar, hence could be an alternative in cases that conventional therapy cannot be used for any reason.

Linear scar reduction using silicone gel sheets in individuals with normal healing

OBJECTIVE

To examine the application of silicone gel sheets on linear scars due to surgical procedures.

METHOD

Ten individuals, with scars less than I year old, participated in the study. The Participant and Observer Scar Assessment Scale (POSAS) was used to evaluate scars on seven characteristics rated by visual analogue scales 0fAS). Participants applied silicone gel sheets to half of their scar for 6 months, and every 2 weeks POSAS data forms were completed. Linear mixed-effects analysis of variances (ANOVA)were used to determine if significant differences occurred between groups (treated and untreated scarsides) across the 6 months of data collection. To see if differences were found from the initial evaluation to final visit, Mann-Whitney U tests analysed between-group changes (treated and untreated scar sides), while Wilcoxon signed ranks tests compared within-group changes (evaluation of each scar side over time).

RESULTS

No significant differences in VAS ratings were observed when the two scar sides were compared, with the exception of overall opinion of the scar, as rated by an observer. For each group,significant changes from baseline to study end were observed for colour, stiffness and irregularities, as rated by the participant. Significant improvements for the treated versus untreated group were observed for pliability and pigmentation, as rated by the observer scale.

CONCLUSION

There was no evidence for improved healing when using silicone gel sheets. The results do not support using silicone gel sheets on linear scars for individuals with no history of abnormal scarring.

The modified Patient and Observer Scar Assessment Scale: a novel approach to defining pathologic and nonpathologic scarring

BACKGROUND

Scarring is a highly prevalent and multifactorial process, yet no studies to date have attempted to distinguish pathologic from nonpathologic scarring.

METHODS

This article defines and proposes methods of classifying pathologic scarring as it pertains to clinical presentation.

RESULTS

The authors propose a new scar scale that incorporates pain and functional impairment.

CONCLUSIONS

The modified Patient and Observer Scar Assessment Scale is the first of its kind to factor in the functional deficits pain and pruritus of scarring into measurements of associated morbidity. This scale has great potential in evaluating patient response to treatment and analyzing clinical outcomes.

Videocapillaroscopy in postburn scars: in vivo analysis of the microcirculation

OBJECTIVE

The aim of the study was the evaluation in vivo of the differences between the microcirculatory characteristics of the postburn scar and the healthy skin.

METHODS

Twelve patients with postburn scars were included in the study, evaluating fifteen scar areas and twelve healthy skin areas by means of contact optical probe videocapillaroscopy. The examined areas for each patient were the right and the left upper limb. Capillary density, length and diameter, together with capillary distribution pattern (punctiform, reticular, directional) and the presence of microhaemorrhages and neoangiogenesis were studied.

RESULTS

The results were obtained by two different researchers using the capillaroscope's software. Capillary loop diameter and length, capillary distribution pattern and presence of neoangiogenesis were found to be significantly increased in postburn scars compared with controls. There were also significant differences between hypertrophic tissue in the active phase and the one in the remission phase for capillary diameter and presence of neoangiogenesis.

CONCLUSION

Videocapillaroscopy showed "in vivo" a change in local microcirculation architecture using a microscope. Patients with hypertrophic burn scars showed a variety of microcirculatory changes, often clustered in a characteristic pattern of abnormally oriented, dilated capillaries and neoangiogenetic phenomena. This methodology is highly likely to be of value in the assessment and prognostication of burn outcome.