Topically delivered dissolved oxygen reduces inflammation and positively influences structural proteins in healthy intact human skin

Oxygenated Hydrogel Promotes Re-Epithelialization and Reduces Inflammation in a Perturbed Wound Model in Rat

Chronic wounds can take months or even years to heal and require proper medical intervention. Normal wound healing processes require adequate oxygen supply. Accordingly, destroyed or inefficient vasculature leads to insufficient delivery to peripheral tissues and impair healing. Oxygen is critical for vital processes such as proliferation, collagen synthesis and antibacterial defense. Hyperbaric oxygen therapy (HBOT) is commonly used to accelerate healing however, this can be costly and requires specialized training and equipment. Efforts have turned to the development of topical oxygen delivery systems. Oxysolutions has developed oxygenated gels (P407, P407/P188, nanocellulose based gel (NCG)) with high levels of dissolved oxygen. This study aims to evaluate the efficacy of these newly developed oxygenated products by assessing their impact on healing rates in a rat perturbed wound model. Here, P407/P188 oxygenated gels demonstrated greater re-epithelialization distances compared to its controls at Day 3. In addition, all oxygenated gels had a higher proportion of wounds with complete wound closure. All three oxygenated gels also minimized further escalation in inflammation from Day 3 to Day 10. This highlights the potential of this newly-developed oxygenated gels as an alternative to existing oxygen therapies.

Dissolved oxygen technologies as a novel strategy for non-healing wounds: A critical review

Non-healing wounds are steadily becoming a global-health issue. Prolonged hypoxia propagates wound chronicity; yet, oxygenating treatments are considered inadequate to date. Dissolved oxygen (DO) in aqueous solutions introduces a novel approach to enhanced wound oxygenation, and is robustly evaluated for clinical applications. A systematic literature search was conducted, whereby experimental and clinical studies of DO technologies were categorized per engineering approach. Technical principles, methodology, endpoints and outcomes were analysed for both oxygenating and healing effects. Forty articles meeting our inclusion criteria were grouped as follows: DO solutions (17), oxygen (O₂ ) dressings (9), O₂ hydrogels (11) and O₂ emulsions (3). All technologies improved wound oxygenation, each to a variable degree. They also achieved at least one statistically significant outcome related to wound healing, mainly in epithelialization, angiogenesis and collagen synthesis. Scarcity in clinical data and methodological variability precluded quantitative comparisons among the biotechnologies studied. DO technologies warrantee further evaluation for wound oxygenation in the clinical setting. Standardised methodologies and targeted research questions are pivotal to facilitate global integration in healthcare.

Development of a novel in situ gelling skin dressing: Delivering high levels of dissolved oxygen at pH 5.5

BACKGROUND AND AIMS

Wound healing requires appropriate oxygen and pH levels. Oxygen therapy and pH-modulating treatments have shown positive effects on wound healing. Thus, a dressing, which combines high levels of dissolved oxygen (DO) with the pH of intact skin, may improve wound healing. Our aims were to (1) formulate an in situ gelling dressing with high levels of DO and with the pH level of intact skin, (2) evaluate physical and chemical properties of the dressing, and (3) elucidate basic effects of elevated levels of DO on human skin cells in vitro.

METHODS

A dressing was formulated with 15 to 16 wt% poloxamer 407, acetate buffer, and oxygenated water. Stability of pH and DO, rheology, and shelf life were analysed. Furthermore, in vitro studies of the effect of increased levels of DO were performed.

RESULTS

An in situ gelling wound dressing, with a DO concentration ranging between 25 and 35 mg/L and a pH of 5.5, was formulated. The DO concentration was stable above 22 mg/L for at least 30 hours when applied on a surface at 35°C and covered for directed diffusion into the intended wound area. At storage, the dressing had stable pH for 3 months and stable DO concentration over 30 mg/L for 7 weeks. Increasing DO significantly enhanced intracellular ATP in human skin cells, without changing reactive oxygen species production, proliferation rate, or viability.

CONCLUSION

The developed dressing may facilitate wound healing by delivering controlled and stable oxygen levels, providing adjustable pH for optimized healing, and increasing intracellular ATP availability.

Topical oxygen therapy & micro/nanobubbles: a new modality for tissue oxygen delivery

Up to 15 billion dollars of US health care expenditure each year is consumed by treatment of poorly healing wounds whose etiologies are often associated with aberrancies in tissue oxygenation. To address this issue, several modes of tissue oxygen delivery systems exist, including Hyperbaric Oxygen Therapy (HBOT) and Topical Oxygen Therapy (TOT), but their efficacies have yet to be fully substantiated. Micro/nanobubbles (MNBs), which range anywhere from 100 μm to <1 μm in diameter and are relatively stable for hours, offer a new mode of oxygen delivery to wounds. The aim of this article is to systematically review literature examining the use of TOT for wound healing and use of MNBs for tissue oxygenation using the MEDLINE database. The search yielded 87 articles (12 MNB articles and 75 TOT articles), of which 52 met the inclusion criteria for this literature review (12 MNB articles and 40 TOT articles). Additionally, we present an analysis on the efficacy of our MNB generating technology and propose its use as a wound healing agent.

Advanced Therapeutic Dressings for Effective Wound Healing--A Review

Advanced therapeutic dressings that take active part in wound healing to achieve rapid and complete healing of chronic wounds is of current research interest. There is a desire for novel strategies to achieve expeditious wound healing because of the enormous financial burden worldwide. This paper reviews the current state of wound healing and wound management products, with emphasis on the demand for more advanced forms of wound therapy and some of the current challenges and driving forces behind this demand. The paper reviews information mainly from peer-reviewed literature and other publicly available sources such as the US FDA. A major focus is the treatment of chronic wounds including amputations, diabetic and leg ulcers, pressure sores, and surgical and traumatic wounds (e.g., accidents and burns) where patient immunity is low and the risk of infections and complications are high. The main dressings include medicated moist dressings, tissue-engineered substitutes, biomaterials-based biological dressings, biological and naturally derived dressings, medicated sutures, and various combinations of the above classes. Finally, the review briefly discusses possible prospects of advanced wound healing including some of the emerging physical approaches such as hyperbaric oxygen, negative pressure wound therapy and laser wound healing, in routine clinical care.

Statistical reporting in randomized controlled trials from the dermatology literature: a review of 44 dermatology journals

BACKGROUND

The validity of randomized controlled trials (RCTs) is determined by several statistical factors.

OBJECTIVES

To determine the level of recent statistical reporting in RCTs from the dermatology literature.

METHODS

We searched MEDLINE for all RCTs published between 1 May 2013 and 1 May 2014 in 44 dermatology journals.

RESULTS

Two hundred and ten articles were screened, of which 181 RCTs from 27 journals were reviewed. Primary study outcomes were met in 122 (67.4%) studies. Sample size calculations and beta values were reported in 52 (28.7%) and 48 (26.5%) studies, respectively, and nonsignificant findings were supported in only 31 (17.1%). Alpha values were reported in 131 (72.4%) of studies with 45 (24.9%) having two-sided P-values, although adjustment for multiple statistical tests was performed in only 16 (9.9% of studies with ≥ two statistical tests performed). Sample size calculations were performed based on a single outcome in 44 (86.3%) and multiple outcomes in six (11.8%) studies. However, among studies that were powered for a single primary outcome, 20 (45.5%) made conclusions based on multiple primary outcomes. Twenty-one (41.2%) studies relied on secondary/unspecified outcomes. There were no differences for primary outcome being met (Chi-square, P = 0.29), sample size calculations (P ≥ 0.55), beta values (P = 0.89), alpha values (P = 0.65), correction for multiple statistical testing (P = 0.59), two-sided alpha (P = 0.64), support of nonsignificant findings (Fisher's exact, P = 0.23) based on the journal's impact factor.

CONCLUSIONS

Levels of statistical reporting are low in RCTs from the dermatology literature. Future work is needed to improve these levels of reporting.