Levels of plasma matrix metalloproteinases (MMP-2 and MMP-9) in response to INTEGRA® dermal regeneration template implantation

Fibrosis in burns: an overview of mechanisms and therapies

Scar development remains a common occurrence and a major healthcare challenge affecting the lives of millions of patients annually. Severe injuries to the skin, such as burns can lead to pathological wound healing patterns, often characterized by dermal fibrosis or excessive scarring, and chronic inflammation. The two most common forms of fibrotic diseases following burn trauma are hypertrophic scars (HSCs) and keloids, which severely impact the patient's quality of life. Although the cellular and molecular mechanisms are similar, HSC and keloids have several distinct differences. In this review, we discuss the different forms of fibrosis that occur postburn injury, emphasizing how the extent of burn influences scar development. Moreover, we highlight how a systemic response induced by a burn injury drives wound fibrosis, including both the role of the inflammatory response, as well as the fate of fibroblast during skin healing. Finally, we list potential therapeutics aimed at alleviating pathological scar formation. An understanding of the mechanisms of postburn fibrosis will allow us to effectively move studies from bench to bedside.

Effect of novel carboxymethyl cellulose-based dressings on acute wound healing dynamics

The clinical implications and efficacy of newly developed modified cellulose materials were evaluated in an acute wound animal model. In the current study, sixty male rats were divided into four groups. A full-thickness circular excision wound was created in the suprascapular area. Newly developed matrices (acidic partially carboxymethylated cellulose; acidic partially carboxymethylated cellulose impregnated with a povidone-iodine solution) were applied in two test groups, while fifteen animals were used as a control group without any primary dressing. Aquacel Ag, a clinically used dressing, was selected as the reference material. To compare the efficacy in vivo, the wound size and production of selected cytokines and growth factors (TNF-α, TGF-β1, and VEGF), which play a key role in the healing process, were measured at two, seven, and fourteen days after surgery. The activity of matrix metalloproteinases 2 and 9, which actively participate in cell signalling and are essential for tissue remodelling, was determined in wound tissue by gelatin zymography. A positive effect of the newly developed dressing materials on the healing process, tissue granulation, and wound re-epithelialisation was demonstrated.

Current Approaches Targeting the Wound Healing Phases to Attenuate Fibrosis and Scarring

Cutaneous fibrosis results from suboptimal wound healing following significant tissue injury such as severe burns, trauma, and major surgeries. Pathologic skin fibrosis results in scars that are disfiguring, limit normal movement, and prevent patient recovery and reintegration into society. While various therapeutic strategies have been used to accelerate wound healing and decrease the incidence of scarring, recent studies have targeted the molecular regulators of each phase of wound healing, including the inflammatory, proliferative, and remodeling phases. Here, we reviewed the most recent literature elucidating molecular pathways that can be targeted to reduce fibrosis with a particular focus on post-burn scarring. Current research targeting inflammatory mediators, the epithelial to mesenchymal transition, and regulators of myofibroblast differentiation shows promising results. However, a multimodal approach addressing all three phases of wound healing may provide the best therapeutic outcome.

The effect of biological sealants and adhesive treatments on matrix metalloproteinase expression during renal injury healing

Background

Renal injuries are relatively common in cases of abdominal trauma. Adhesives and sealants can be used to repair and preserve damaged organs. Using a rat model, this study explores the activity of different matrix metalloproteinases (MMP) during the healing of renal injuries treated by two biological adhesives (TachoSil and GelitaSpon) and a new synthetic elastic cyanoacrylate (Adhflex).

Methods

Renal traumatic injuries were experimentally induced in 90 male Wistar rats by a Stiefel Biopsy Punch in the anterior aspect of the left kidney. Animals were divided into five groups: 1, sham non-injured (n = 3); 2, non-treated standard punch injury (n = 6); 3, punch injury treated with TachoSil (n = 27); 4, punch injury treated with GelitaSpon (n = 27); and, 5, punch injury treated with Adhflex (n = 27). Wound healing was evaluated 2, 6, and 18 days after injury by determining the expression of MMPs, and the histopathological evolution of lesions.

Findings

Histologically, the wound size at 6 days post-injury was larger in Adhflex-treated samples than in the other treatments, but the scarring tissue was similar at 18 days post-injury. Only the MMPs subtypes 1, 2, 8, 9, and 13 were sufficiently expressed to be quantifiable. Both time since injury and treatment type had a significant influence on MMPs expression. Two days after injury, the expression of MMP8 and MMP9 was predominant. MMP2 expression was greater 6 days after injury. The Adhflex-treated group had a significantly higher MMPs expression than the other treatment groups at all healing stages.

Conclusions

All three sealant treatments induced almost similar expression of MMPs than untreated animals indicating a physiological healing process. Given that all renal trauma injuries must be considered emergencies, both biological and synthetic adhesives, such as Adhflex, should be considered as a treatment options.

Association between four MMP-9 polymorphisms and breast cancer risk: a meta-analysis

BACKGROUND

The role of matrix metalloproteinase 9 (MMP-9) polymorphisms in breast cancer risk remains unclear. The purpose of this study was to evaluate the association between MMP-9 variants and breast cancer susceptibility.

MATERIAL AND METHODS

Case-control studies were searched on electronic databases to retrieve related articles published between 2000 and 2014 concerning the role of MMP-9 variants in breast cancer risk. Pooled odds ratios (OR) with correlative 95% confidence intervals (CI) were employed to assess this association.

RESULTS

Ten articles were screened out, including 6177 breast cancer patients and 6726 matched-controls. For rs3918242 (-1562 C/T), 6 studies contained 1435 patients and 1446 controls. Although the frequency of risk allele C was higher in breast cancer patients than in controls, only TT genotype in recessive model was significantly associated with increased risk of breast cancer (TT vs. CT+CC: OR=1.55, 95% CI=1.12-2.16, P=0.009) in a fixed-effects model. This significant relationship was not observed in other genetic models (P>0.05). No significant association was found between breast cancer risk and rs17576, rs2250889, and rs3787268 under any genetic models.

CONCLUSIONS

Our results show that TT genotype of MMP-9-1562 C/T polymorphism might be a risk factor for breast cancer. More studies are needed to further explore this association.