The role of hyaluronic acid in wound healing’s proliferative phase

Synergy of Hydeal-D® and Hyaluronic Acid for Protecting and Restoring Urothelium: In Vitro Characterization

Interstitial cystitis (IC) or painful bladder syndrome is a chronic dysfunction due to an inflammatory condition, characterized by bladder pain and urinary frequency. Currently, no gold standard therapy is available since IC does not respond to conventional ones. Given these premises, the aim of this work was the in vitro characterization of biological properties (mucoadhesion and anti-inflammatory activity) of a commercial product (HydealCyst–HydC) based on hyaluronic acid (HA) and the benzyl ester of HA (Hydeal-D^®) intended for bladder instillation to restore and/or protect the urothelial layer of glycosamino glycans (GAGs). The in vitro characterization demonstrated that an interaction product is formed between HA and Hydeal-D^® that has a role in the rheological behavior and mucoadhesive properties. HA was identified as a key component to form the mucoadhesive joint, while the interaction of HA with Hydeal-D^® improved polysaccharide stability and prolonged the activity ex vivo. Moreover, HydC is cytocompatible with urothelial cells (HTB-4) and possesses an anti-inflammatory effect towards these cells by decreasing the secretion of IL-6 and IL-8, which were both increased in patients with IC, and by increasing the secretion of sulfated GAGs. These two findings, along with the resilience properties of the formulation due to mucoadhesion, suggest the active role of HydC in protecting and restoring urothelium homeostasis.

Comparison of the effect of postoperative care agents on human gingival fibroblasts: a preliminary study

Purpose:

The aim of this study is to compare effects of postoperative care agents; chlorhexidine, octenidine dihydrochloride and hyaluronic acid on human gingival fibroblasts’ viability, proliferation, apoptosis and migration.

Materials and methods:

After cell culturing; chlorhexidine, octenidine dihydrochloride and hyaluronic acid solutions were applied on cells and nothing was applied for control group. The cells were monitored to investigate cytotoxicity; the percentage of apoptotic, living and dead cells at the time of 24, 48, and 72 hours (h). A scratch wound assay was performed to detect cell migration and cells were monitored at baseline, at 24 and 48h.

Results:

At 24h, chlorhexidine showed statistically lower percentage of total apoptotic cells’ than octenidine dihydrochloride (p=0.049), hyaluronic acid (p=0.049) and control (p=0.049). At 48h, hyaluronic acid showed statistically lower percentage than chlorhexidine (p=0.049), and control (p=0.049). All agents were found to have statistically and significantly more cytotoxic than control. However, there was no difference between experimental groups for proliferation rate. Octenidine dihydrochloride showed statistically negative effects on cell migration than chlorhexidine and hyaluronic acid at 24h. Chlorhexidine and hyaluronic acid maintained migration ability of cells than octenidine dihydrochloride at 48h.

Conclusion:

All agents have similar effects on cell behavior such as viability, apoptosis and cell proliferation. However, octenidine dihydrochloride showed statistically negative effects on migration ability than chlorhexidine and hyaluronic acid.

Roles of Proteoglycans and Glycosaminoglycans in Wound Healing and Fibrosis

A wound is a type of injury that damages living tissues. In this review, we will be referring mainly to healing responses in the organs including skin and the lungs. Fibrosis is a process of dysregulated extracellular matrix (ECM) production that leads to a dense and functionally abnormal connective tissue compartment (dermis). In tissues such as the skin, the repair of the dermis after wounding requires not only the fibroblasts that produce the ECM molecules, but also the overlying epithelial layer (keratinocytes), the endothelial cells, and smooth muscle cells of the blood vessel and white blood cells such as neutrophils and macrophages, which together orchestrate the cytokine-mediated signaling and paracrine interactions that are required to regulate the proper extent and timing of the repair process. This review will focus on the importance of extracellular molecules in the microenvironment, primarily the proteoglycans and glycosaminoglycan hyaluronan, and their roles in wound healing. First, we will briefly summarize the physiological, cellular, and biochemical elements of wound healing, including the importance of cytokine cross-talk between cell types. Second, we will discuss the role of proteoglycans and hyaluronan in regulating these processes. Finally, approaches that utilize these concepts as potential therapies for fibrosis are discussed.

The antioxidant and anti-inflammatory efficiency of hyaluronic acid after third molar extraction

PURPOSE

Hyaluronic acid (HA) has a number of clinical applications in current practice. Therefore, correlation of HA with free radicals and inflammatory cells is clinically important. The purpose of this study is to measure the efficacy of high molecular weight HA on the oxidative stress of oral wounds (glutathione (GSH) and lipid peroxidation (LPO) levels), the inflammatory reaction (leucocytes, collagen and angiogenesis content), pain (visual analogue scale (VAS) records) and trismus (maximum interincisal opening (MIO) records) after third molar (M3) extraction.

PATIENTS AND METHODS

40 patients were included in this study. 0.2 ml 0.8% HA was applied immediately after surgery within the HA group (n = 20). Nothing was applied to the control group (n = 20). The primary outcome variables were the changes in the inflammatory reaction (leucocyte, angiogenesis and collagen content), oxidative stress (GSH, LPO) and clinical parameters (VAS, MIO). Results were compared immediately after extraction (T0) and 1 week after surgery (T1). Bivariate analyses were used to assess the differences between the HA and control groups for each study variable.

RESULTS

There was a statistically significant difference of leucocyte infiltration and angiogenesis between the groups at T1. The HA group showed less leucocyte infiltration and more angiogenesis than the control group. There was no statistically significant difference in oxidative stress, VAS or MIO levels between the groups.

CONCLUSION

Our results confirm the hypothesis that HA has an anti-inflammatory effect following M3 extraction. However, the oxidative stress levels and clinical outcomes were similar after one week. Further studies examining these parameters at different times are necessary.

RCT to evaluate a hyaluronic acid containing gauze pad in leg ulcers of venous or mixed aetiology

OBJECTIVE

To investigate the efficacy and safety of an hyaluronic acid (HA)-impregnated gauze pad compared with a hydrocolloid (HC) dressing, in patients with leg ulcer of venous or mixed aetiology.

METHOD

A 56-day blind-observer, randomised, multicentre, controlled, non-inferiority trial. Patients were randomised to receive either an HA gauze pad (ialuset gauze pad) or an HC dressing (DuoDERM E).The primary endpoint was the difference between the groups regarding the percentages of patients achieving a reduction of at least 40% of the initial wound surface after 56 days of treatment (visit 5). Secondary endpoints included reduction of wound area, aspect of the wound (percentage of necrotic,fibrinous or granulation tissue), rate of complete ulcer healing, pain intensity, and clinical status of the peri-ulcerous skin.

RESULTS

In total, 170 patients were included and analysed in the intention-to-treat (ITT) population; 27 patients presented at least one major protocol deviation and were excluded from the per-protocol (PP) population.Therefore, 143 patients constituted the PP population (n=72 and n=71 in the HA gauze pad group and HC dressing group, respectively).At day 56, the confidence interval of the difference between the two groups for the percentage of patients with a reduction of at least 40% of the target ulcer initial surface was [-0.128; 0.164] with a lower limit above the non-inferiority threshold (-0.15). Peri-ulcerous skin was significantly less impaired in the HA gauze pad group for oedema at day 56 (p = 0.04), purpura at day 14 (p = 0.009) and for maceration at day 14 (p = 0.003). Other secondary endpoints were not significantly different between the two groups. Overall, both treatments were well tolerated and adverse events were comparable between the two groups regarding their pattern, frequency, likely relationship to treatment and severity which was mostly mild (grade I) or moderate (grade 2). These results were confirmed in the overall ITT population.

CONCLUSION

These data support the non-inferiority of the HA gauze pad compared with HC for the primary endpoint.The significant differences in favour of HA gauze pad regarding peri-ulcerous skin changes (oedema, purpura and maceration) may suggest a trend for HA gauze pad to have a better acceptability than the reference HC dressing.

DECLARATION OF INTEREST

This study was sponsored by Laboratoires Genévrier. Authors received honoraria for their contributions to the study, but have no other conflicts of interests to declare.

Repair of tympanic membrane perforation using novel adjuvant therapies: a contemporary review of experimental and tissue engineering studies

OBJECTIVE

To perform a contemporary review of experimental studies to describe the effects of various novel adjuvant therapies in enhancing tympanic membrane (TM) perforation healing.

METHODS

A PubMed search for articles from January 2000 to June 2012 related to TM perforation, along with the references of those articles, was performed. Inclusion and exclusion criteria were applied to all experimental studies assessing adjuvant therapies to TM healing.

RESULTS

Many studies have assessed the efficacy of biomolecules or growth factors, such as epidermal growth factors and basic fibroblast growth factors, in TM regeneration with significant success. More recent strategies in TM tissue engineering have involved utilizing bioengineered scaffold materials, such as silk fibroin, chitosan, calcium alginate, and decellularized extracellular matrices. Most scaffold materials demonstrated biocompatibility and faster TM perforation healing rates.

CONCLUSION

Although several studies have demonstrated promising results, many questions still remain, such as the adequacy of animal models and long-term biocompatibility of adjuvant materials. As well, further studies comparing various adjuvant substances and bioscaffolds are required prior to clinical application.

Effects of a cross-linked hyaluronic acid based gel on the healing of open wounds in dogs

OBJECTIVE

To compare effects of a cross-linked hyaluronic acid (HA) based gel (CMHA-S) to a standard wound management protocol on the healing of acute, full-thickness wounds in dogs.

STUDY DESIGN

A prospective, controlled, experimental study.

ANIMALS

Purpose-bred, adult, female beagles (n = 10).

METHODS

Two 2 × 2 cm wounds were surgically created bilaterally on the trunk of each dog and each side randomized to treatment (CMHA-S) or control (CON) groups. Total and open wound areas were measured with digital image planimetry at 15 time points. From these data, percent contraction and percent epithelialization were calculated. Tissue biopsies were obtained at 6 time points and histologic features were scored.

RESULTS

Total wound area was significantly larger and percent contraction was significantly less in CMHA-S compared to CON wounds at all data points between days 9 and 18. At day 25, and for the remainder of the study, CMHA-S wounds were smaller and contracted more than CON wounds, reaching significance at day 32. Percent epithelialization was significantly less in CMHA-S compared to CON wounds at all data points after day 11. Histologically, fibroblastic cellular infiltration was significantly higher in CMHA-S wounds at day 21.

CONCLUSIONS

CMHA-S wounds healed more slowly than CON wounds. This HA-based gel is not indicated in acute, full-thickness skin wounds in dogs as administered in this study. However, treatment may be beneficial in the mid-to-late repair stage of healing, or if scar minimization is desired. Further studies to evaluate the effects of the CMHA-S gel on canine wounds are indicated.

Efficacy and safety of hyaluronic acid in treatment of leg ulcers: a double-blind RCT

OBJECTIVE

To investigate the efficacy and safety of hyaluronic acid in the local treatment of leg ulcers of venous or mixed aetiology, compared with a neutral vehicle.

METHOD

A 60-day double-blind, randomised, multicentre, controlled superiority trial. The primary endpoint was the percentage wound size reduction after 45 days of treatment. Secondary endpoints included pain intensity, rate of complete ulcer healing, and aspect of the wound (percentage of necrotic, fibrinous or granulation tissue) and of the peri-ulcer skin.

RESULTS

A total of 101 patients were randomised and analysed in the intention-to-treat (ITT) population (50 in the hyaluronic acid; 51 in the control group). Seventy-five patients were considered in the per protocol (PP) population (38 vs 37, respectively). At day 45, the percentage of ulcer surface reduction was significantly greater in the hyaluronic acid treatment group (39 ± 6%) compared with the neutral vehicle (control) group (5 ± 9%) (p=0.002). A similar result was obtained at day 15, day 30 and day 60. From day 0 to day 45, pain intensity (VA S) decreased by mean 9.8 ± 3.5mm in the hyaluronic acid group, but slightly increased by 0.8 ± 3.2mm in the control group (p=0.029). Burden of pain, as estimated by the area under the curve of daily pain (from day 0 to day 60), was significantly lower in the hyaluronic acid group (121.9 ± 20.7mm2) than in the control group (207.4 ± 32.9mm2; p=0.028). Other secondary endpoints (rate of complete healing, characteristics of the wound and peri-ulcer skin) were not significantly different between the two groups. Treatments were well tolerated and adverse events were comparable between the two groups in terms of their frequency, relationship to treatment and severity.

CONCLUSION

Hyaluronic acid cream was significantly more effective than the neutral vehicle in the local treatment of leg ulcers of venous or mixed aetiology, in terms of wound size reduction and reducing the burden of pain, with a good safety profile.

Efficacy and safety of a gauze pad containing hyaluronic acid in treatment of leg ulcers of venous or mixed origin: a double-blind, randomised, controlled trial

Topical hyaluronic acid (HA) is routinely used in the local treatment of chronic wounds, but few data have been reported to date. A 60-day double-blind, randomised, controlled superiority trial was designed to investigate the efficacy and safety of a gauze pad containing HA in local treatment of venous leg ulcers, compared with its neutral vehicle. The primary endpoint was the percentage of wound size reduction after 45 days. Totally 89 patients were included. At day 45, the percentage of ulcer surface reduction was significantly greater in the HA group (73 ± 4·6%) versus neutral vehicle group (46 ± 9·6%) (P = 0·011). The number of healed ulcers was significantly higher in the HA group at day 45 (31·1% versus 9·3% respectively) and day 60 (37·8% versus 16·3% respectively; P < 0·05). At day 30, pain intensity based on visual analogue scale was significantly lower in the HA group (12·4 mm ± 2·6 versus 22·8 mm ± 3·8; P = 0·026). Tolerance of both treatments was comparable in the two groups. HA gauze pad, in local treatment of venous leg ulcers, was significantly more effective than the neutral vehicle on wound size reduction, healed ulcers rate and pain management with a good safety profile.

Wound healing through synergy of hyaluronan and an iodine complex

Hyaluronan, a glycosaminoglycan (GAG), is a polysaccharide found in many locations in the human body, such as eye, skin and soft tissue. It is also found in other mammals and bacteria. As a component of the extracellular matrix, its role in wound repair, among others, is that of providing a temporary structure to support new tissue formation. Harnessing the therapeutic action of hyaluronan into a topical application of proven clinical benefit has proved challenging. A new development in hyaluronan technology, comprising sodium hyaluronate and iodine complex, offers a novel approach in exploiting the benefits of hyaluronan and delivering real clinical benefits for a wide range of wound types.

Initial Experience Using a Hyaluronate-Iodine Complex for Wound Healing

Hyaluronate-iodine complex is a wound healing adjuvant approved for use in the European Union. The objective of this study is to validate hyaluronate-iodine as a potential wound healing agent. Patients were recruited from the hospital, the outpatient clinic, and the wound healing center. Hyaluronate-iodine soaked gauze was applied to wounds either daily or every other day depending on the amount of wound exudate. Wounds were measured weekly, and progression was documented with digital photography. All wounds were debrided as needed using standard surgical techniques. Fourteen patients (19 wounds) were entered into this prospective study, and 10 patients completed treatment. Fourteen wounds progressed to complete healing with a mean healing time of 18.1 ± 15.1 weeks. Treatment was interrupted in four patients. One patient discontinued treatment due to pain related to application of hyaluronate-iodine, another patient for transportation issues, and the other two patients were lost to follow-up due to relocation out of state and noncompliance with scheduled appointments. Hyaluronate-iodine was helpful in the healing of all types of wounds treated in this pilot study. The antiadhesive and antimicrobial properties of hyaluronate-iodine create a desirable environment conducive to wound healing without apparent detrimental effects.

[Hyalomatrix PA(®) in skin substitutes. About 10 cases]

During the surgical treatment of burns and reconstructive surgery, we can use autografts, allografts, xenografts or dermal substitutes. Acellular dermal substitutes, implantable medical devices of class III are composed mostly of collagen but also, more recently, derivatives of hyaluronic acid (Hyalomatrix PA(®)). Their mechanism of action is based on revascularization and colonization by fibroblasts of the patient. They are then used to screen for delayed epidermal grafting (2-stage procedure for Integra(®), Matriderm(®) 2mm, Renoskin(®), Hyalomatrix PA(®)) or simultaneous (1-time procedure for IntegraSL(®), Matriderm(®) 1mm). We report 10 cases of clinical use of Hyalomatrix PA(®) in the service of burns and plastic surgery of Nantes.

Efficacy and tolerance of a hydrocolloid dressing containing hyaluronic acid for the treatment of leg ulcers of venous or mixed origin

OBJECTIVE

This study was aimed at comparing efficacy and tolerance of a new hydrocolloid dressing containing hyaluronic acid (HC + HA) to a reference hydrocolloid not containing hyaluronic acid (HC) in the treatment of leg ulcers of venous or mixed origin.

RESEARCH DESIGN AND METHODS

This was an open, prospective study, randomized in parallel groups, in which 125 patients were enrolled and treated for up to 42 days. The primary efficacy criterion was the reduction of the wound area; other efficacy criteria were the condition of the wound bed, and of the surrounding skin, and presence and severity of symptoms such as pain and itching.

RESULTS

After 42 days of treatment the median reduction of ulcer area was -42.6% (95% confidence interval [CI]: -66.6; -5.7) and -31.0% (95% CI: -51.6; -8.8) in the HC + HA group and in the reference HC group, respectively. The difference between treatments was not statistically significant. A reduction > or = 90% of the initial ulcer area was seen in 15 patients in the HC + HA dressing group and in only seven patients in the HC dressing group. Changes in wound bed condition in the two groups were not significantly different, except for a more marked reduction of fibrinous tissue in the HC + HA dressing group (p = 0.04), at Day 28. Both treatments were well tolerated.

CONCLUSIONS

The HC + HA dressing was equally well tolerated and with a trend to be more effective than the reference HC dressing in the treatment of leg ulcers of venous or mixed origin. Further research is needed to confirm these findings.

Hyaluronan facilitates transforming growth factor-beta1-mediated fibroblast proliferation

This study aims to understand the role of the matrix polysaccharide hyaluronan (HA) in influencing fibroblast proliferation and thereby affecting wound healing outcomes. To determine mechanisms that underlie scarred versus scar-free healing, patient-matched dermal and oral mucosal fibroblasts were used as models of scarring and non-scarring fibroblast phenotypes. Specifically, differences in HA generation between these distinct fibroblast populations have been examined and related to differences in transforming growth factor-beta(1) (TGF-beta(1))-dependent proliferative responses and Smad signaling. There was a differential growth response to TGF-beta(1), with it inducing proliferation in dermal fibroblasts but an anti-proliferative response in oral fibroblasts. Both responses were Smad3-dependent. Furthermore, the two fibroblast populations also demonstrated differences in their HA regulation, with dermal fibroblasts generating increased levels of HA, compared with oral fibroblasts. Inhibition of HA synthesis in dermal fibroblasts was shown to abrogate the TGF-beta(1)-mediated induction of proliferation. Inhibition of HA synthesis also led to an attenuation of Smad3 signaling in dermal fibroblasts. Microarray analysis demonstrated no difference in the genes involved in TGF-beta(1) signaling between dermal and oral fibroblasts, whereas there was a distinct difference in the pattern of genes involved in HA regulation. In conclusion, these two distinct fibroblast populations demonstrate a differential proliferative response to TGF-beta(1), which is associated with differences in HA generation. TGF-beta(1) regulates proliferation through Smad3 signaling in both fibroblast populations; however, it is the levels of HA generated by the cells that influence the outcome of this response.

Effectiveness of MeroGel hyaluronic acid on tympanic membrane perforations

CONCLUSIONS

Our results support the proposition that hyaluronic acid (HA) provides a moist wound-healing environment to aid in the healing process of tympanic membrane perforation. A single MeroGel administration can be effective as well as daily topical HA application in the treatment of tympanic membrane perforations. A single application of esterified HA may be more suitable for patients and also for otolaryngologists.

OBJECTIVE

The purpose of the present study was to evaluate the effectiveness of a single MeroGel application on traumatic tympanic membrane perforations in rats.

MATERIALS AND METHODS

The posterior quadrant of the tympanic membranes in both ears of 24 male pathogen-free Sprague-Dawley rats was perforated with a 20-gauge needle. Subjects were divided into two groups: MeroGel and daily topical HA-treated groups. All subjects were sacrificed and histopathological examinations of the tympanic bullas were carried out.

RESULTS

Perforations of controls, and MeroGel- and daily HA-treated groups closed in 17/24 (70.8%), 11/12 (91.7%), and 12/12 (100%) ears, respectively. There was a significant difference between control and MeroGel-treated groups, and also between control and daily topical HA-treated groups for the presence of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), lymphocytes and collagen fibrils (p<0.05), whereas there was no significant difference between MeroGel- and daily topical HA-treated groups (p>0.05).

The signal-to-noise ratio as a measure of HA oligomer concentration: a MALDI-TOF MS study

MALDI-TOF MS (matrix-assisted laser desorption and ionization time-of-flight mass spectrometry) was used to determine ng amounts of defined hyaluronan (HA) oligomers obtained by enzymatic digestion of high molecular weight HA with testicular hyaluronate lyase. The signal-to-noise (S/N) ratio of the positive and negative ion spectra represents a reliable concentration measure: Amounts of HA down to about 40 fmol could be determined and there is a linear correlation between the S/N ratio and the HA amount between about 0.8 pmol and 40 fmol. However, the detection limits depend considerably on the size of the HA oligomer with larger oligomers being less sensitively detectable. The advantages and drawbacks of the S/N ratio as concentration measure are discussed.

Preparation of the methyl ester of hyaluronan and its enzymatic degradation

A methyl ester of hyaluronan in which the carboxyl groups were fully esterified was prepared using trimethylsilyl diazomethane. This derivative, while not depolymerized by hyaluronan lyases or hyaluronan hydrolases, was a substrate for both chondroitin ACI lyase (EC 4.2.2.5) from Flavobacterium heparinum and chondroitin ACII lyase (EC 4.2.2.5) from Arthrobacter aurescens. The major product isolated in these depolymerization reactions was methyl alpha-L-threo-hex-4-enepyranosyluronate-(1-->3)-2-acetamido-2-deoxy-alpha,beta-D-glucopyranoside as determined by 1H NMR spectroscopy and MALDITOF mass spectrometry.

Second-degree burns: a comparative, multicenter, randomized trial of hyaluronic acid plus silver sulfadiazine vs. silver sulfadiazine alone

AIMS

This multicenter, multinational, randomized, double-blind, controlled, parallel-group study, was designed to assess the efficacy and safety of a fixed combination topical medicinal product, containing 0.2% hyaluronic acid and 1% silver sulfadiazine (HA-SSD) (Connettivina Plus cream) versus 1% silver sulfadiazine cream alone (SSD), in the treatment of second-degree burns.

METHODS

111 adult patients (age 18-75 years) of both sexes, with IIa-degree (superficial) and IIb-degree (deep dermal) burns, were randomized to receive HA-SSD or SSD. Treatments (approximately 5 g/100 cm2) were applied once a day until the wounds healed, but for no longer than 4 weeks. Burns had to have occurred within 48 hours from the start of treatment, be caused by thermal injury, and be confined to the trunk and/or upper and lower extremities.

RESULTS

Results showed that both the fixed combination HA-SSD, and SSD alone, were effective and well tolerated topical agents for the treatment of second-degree burns. All burns were healed except in one patient treated with SSD. It was also observed that the fixed combination HA-SSD caused a significantly more rapid re-epithelialization of burns, i.e. a shorter time to healing, than SSD alone. The difference recorded--4.5 days--was statistically significant (p = 0.0073).

CONCLUSION

The observed shorter time to healing caused by the fixed combination is clinically relevant and further demonstrates the wound healing activity of HA.