Étude pilote d’un nouvel agent de thérapie matricielle (RGTA OTR4120®) dans les ulcères de cornée et les dystrophies cornéennes rebelles

Treatment of Non-Infectious Corneal Injury: Review of Diagnostic Agents, Therapeutic Medications, and Future Targets

Corneal injuries can occur secondary to traumatic, chemical, inflammatory, metabolic, autoimmune, and iatrogenic causes. Ocular infection may frequently occur concurrent to corneal injury; however, antimicrobial agents are excluded from this present review. While practitioners may primarily rely on clinical examination techniques to assess these injuries, several pharmacological agents, such as fluorescein, lissamine green, and rose bengal, can be used to formulate a diagnosis and develop effective treatment strategies. Practitioners may choose from several analgesic medications to help with patient comfort without risking further injury or delaying ocular healing. Atropine, cyclopentolate, scopolamine, and homatropine are among the most frequently used medications for this purpose. Additional topical analgesic agents may be used judiciously to augment patient comfort to facilitate diagnosis. Steroidal anti-inflammatory agents are frequently used as part of the therapeutic regimen. A variety of commonly used agents, including prednisolone acetate, loteprednol, difluprednate, dexamethasone, fluorometholone, and methylprednisolone are discussed. While these medications are effective for controlling ocular inflammation, side effects, such as elevated intraocular pressure and cataract formation, must be monitored by clinicians. Non-steroidal medications, such as ketorolac, bromfenac, nepafenac, and diclofenac, are additionally used for their efficacy in controlling ocular inflammation without incurring side effects seen with steroids. However, these agents have their own respective side effects, warranting close monitoring by clinicians. Additionally, ophthalmologists routinely employ several agents in an off-label manner for supplementary control of inflammation and treatment of corneal injuries. Patients with corneal injuries not infrequently have significant ocular surface disease, either as a concurrent pathology or as an exacerbation of previously existing disease. Several agents used in the management of ocular surface disease have also been found to be useful as part of the therapeutic armamentarium for treatment of corneal injuries. For example, several antibiotics, such as doxycycline and macrolides, have been used for their anti-inflammatory effects on specific cytokines that are upregulated during acute injuries. There has been a recent wave of interest in amniotic membrane therapies (AMTs), including topical, cryopreserved and dehydrated variants. AMT is particularly effective in ocular injuries with violation of corneal surface integrity due to its ability to promote re-epithelialization of the corneal epithelium. Blood-based therapies, including autologous serum tears, plasma-enriched growth factor eyedrops and autologous blood drops, have additionally been explored in small case series for effectiveness in challenging and recalcitrant cases. Protection of the ocular surface is also a vital component in the treatment of corneal injuries. Temporary protective methods, such as bandage contact lenses and mechanical closure of the eyelids (tarsorrhaphy) can be particularly helpful in selective cases. Glue therapies, including biologic and non-biologic variants, can also be used in cases of severe injury and risk of corneal perforation. Finally, there are a variety of recently introduced and in-development agents that may be used as adjuvant therapies in challenging patient populations. Neurotrophic corneal disease may occur as a result of severe or chronic injury. In such cases, recombinant human nerve growth factor (cenegermin), topical insulin, and several other novel agents may be an alternate and effective option for clinicians to consider.

Advances in the Medical Management of Neurotrophic Keratitis

Neurotrophic Keratitis (NK) is a degenerative disorder of the cornea characterized by decreased or absent sensory corneal innervation, corneal epitheliopathy and impaired healing.The clinical presentation of NK can range from persistent epithelial defects to corneal perforation and management is often both challenging and protracted. Historically, the management of NK has consisted of non-specific strategies to facilitate corneal epithelial healing such as lubrication, bandage contact lenses and tarsorrhaphy. Recent advances in the development of therapeutics for NK have provided new and efficacious targeted strategies for its management.In this article, we review recombinant human nerve growth factor (Cenegermin), currently approved for clinical use in the United States and Europe, as well as other promising therapeutic options that are in pre-clinical development such as thymosine β4, connexin43 inhibitors, and artificial extracellular matrix components.

Matrix Regenerating Agent (RGTA) in a Neurotrophic Corneal Ulcer

Neurotrophic keratopathy is a condition associated with corneal damage and impaired corneal healing. There are no specific treatments available for this disease and current treatments are not associated with improved visual function. Matrix regenerating agents (RGTA) are recent topical agents showing positive results in the treatment of several corneal conditions, including neurotrophic keratopathy.

We report the case of a 73-year-old patient with a neurotrophic ulcer treated with RGTA.

Treatment with RGTA allowed complete corneal healing and a dramatic recovery in visual function in our patient. RGTA solutions are an important and safe therapeutic option for the treatment of selected corneal pathology.

Fast and sustained healing of resistant corneal ulcers using corneal scrubbing and matrix regenerating therapy

AIM

The aim of this study was to assess the efficacy and safety of corneal scrubbing associated with matrix regenerating agent on corneal wound healing in patients with persistent corneal ulcers.

METHODS

This was a retrospective case study in patients with difficult-to-treat corneal ulcer. Corneal scrubbing was performed with a sterile dry cotton bud to eliminate damaged epithelial cells and corneal deposits, promoting epithelial renewal. Regenerating agent was then administered as one eye drop every 2 days in addition to preservative-free ocular lubricants. A bandage contact lens was applied in case of moderate-to-severe corneal pain. Corneal ulcers were regularly assessed until healing.

RESULTS

In total, 17 patients with a chronic corneal ulcer of various etiologies for several months on average were enrolled. Corneal scrubbing combined with regenerating agent administration led to a rapid corneal ulcer size reduction from 26.4 ± 20.6 mm² after scrubbing (before regenerating agent) to 7.2 ± 7.1 mm² at day 5, 3.3 ± 6.0 mm² at day 10, and 0.9 ± 2.3 mm² at day 18. Complete corneal ulcer healing was observed in 35.2% of patients within 10 days, in 70.4% within 18 days, and in all patients within 25 days. Corneal ulcer relapse was observed in two (11.8%) patients after 6 weeks and 5 months, respectively; both were successfully treated using the same procedure. The regenerating agent was well tolerated in all patients.

CONCLUSION

In this study, combined corneal scrubbing and matrix regenerating therapy (with or without bandage contact lens) led to a rapid healing and successful resolution of persisting corneal ulcers, including large and deep corneal ulcers.

Case Reports for Topical Treatment of Corneal Ulcers with a New Matrix Therapy Agent or RGTA® in Dogs

Superficial corneal ulcers that fail to heal within a normal time period and are refractory to conventional therapy in dogs are common in veterinary practice. Different etiologies can lead to this result, including spontaneous chronic corneal epithelial defects (SCCEDs) and ulcerative keratitis associated with bullous keratopathy. Thus, there is an urgent need to find new therapeutic approaches such as matrix therapy replacement. To determine the efficacy of a new ophthalmic treatment (Clerapliq^®) for SCCEDs and ulcerative keratitis associated with bullous keratopathy, a total of 11 dogs referred to the clinic because of nonhealing erosive ulcers after a classic primary treatment were enrolled to get this new treatment. Dogs underwent ophthalmic exams and 7 dogs (10 eyes) were diagnosed with superficial ulceration and 4 dogs (5 eyes) with bullous keratopathy due to endothelial dystrophy/degeneration. They received eye drops of Clerapliq^® every 3 days until recovery. The results showed that the corneas with recurrences of the ulcers were resolved predominantly by using Clerapliq^® every 3 days in 83.3% of the cases during a period of treatment ranging between 6 to 35 days. Therefore, this new approach using matrix therapy regenerating technology in treating superficial ulcers and bullous keratopathy in dogs can be successfully considered as an adjunctive therapy.

Matrix therapy is a cost-effective solution to reduce amputation risk and improve quality of life: pilot and case studies

Introduction: Chronic, non-healing ulcers remain one of the most challenging clinical situations for health care practitioners. Often, conventional treatments fail and lead to amputation, further decreasing the patient's quality of life and resulting in enormous medical expenditures for healthcare systems. Here we evaluated the use of and cost-effectiveness of the RGTA (ReGeneraTing Agents) medical device CACIPLIQ20 (OTR4120) for chronic lower-extremity ulcers in patients with Leriche and Fontaine Stage IV peripheral arterial disease who were not eligible for revascularization. Methods: This uncontrolled pilot study included 14 chronic lower extremity ulcers in 12 patients in one hospital. The pilot study included 12 patients with TcPO₂ < 20 mm Hg and ABPI < 0.5 who had either a minimum of one chronic lower extremity ulcer or a chronic ulcer related to amputation. OTR4120 was applied twice a week or until complete healing, for up to 12 weeks. Ulcer surface area reduction (%)after 2, 4, 8 and 12 weeks, appearance after 4 weeks, and healing after 12 weeks were measured and recorded. Results: A 35% reduction in ulcer size was achieved after 4 weeks. 7 (50%) out of 14 ulcers completely healed within 1 to 3 months of treatment. Discussion: OTR4120 is an effective therapeutic option for patients with chronic lower extremity ulcers, can provide major improvement of quality of life and has the added benefit of being a significant cost-effective solution for healthcare systems.

Recent innovations with drugs in clinical trials for neurotrophic keratitis and refractory corneal ulcers

Introduction: Corneal ulcers normally resolve spontaneously because of the proliferative ability of the corneal epithelium; however, sometimes, epithelial healing is diminished, even when standard treatments are administered. Hence, the treatment of refractory corneal ulcers is challenging and is the subject of ongoing efforts in preclinical and clinical development. Emerging treatment approaches include thymosine β4, CODA001, and topical insulin. Cenegermin eye drops, containing recombinant human nerve growth factor and ReGenerating Agent, a matrix therapy agent, have recently been commercialized for the treatment of moderate to severe neurotrophic keratitis in adults.Areas covered: We describe emerging therapeutic approaches for the management of refractory corneal ulcers and treatments recently introduced to the market. Pubmed and Clinicaltrial.gov databases were first searched including the terms: "corneal ulcer" or "neurotrophic keratopathy" and "treatment." Each treatment was searched in the same databases separately.Expert opinion: Affections of the sensory corneal nerves are the main factor contributing to the pathophysiology of neurotrophic keratopathy; this explains the healing difficulties of this form of ulcer. Cenegermin is a promising therapy acting as a neurotrophic agent for corneal healing. ReGenerating Agent has led to rapid pain relief and corneal healing, but randomized clinical trials are still necessary for further assessment.

Antiviral effects of Cacicol®, a heparan sulfate biomimetic for corneal regeneration therapy, for herpes simplex virus type-1 and varicella zoster virus infection

BACKGROUND

Cacicol^®, a topical eye biopolymer containing a poly-carboxymethylglucose sulfate solution that is a regenerating matrix therapy agent, intended for wound healing of persistent corneal epithelial defects. Based on the chemical composition, we hypothesized that Cacicol^® may compete with natural heparan sulfate (HS) which initiates cell surface attachment of herpes simplex virus type-1 (HSV-1), varicella zoster virus (VZV) and human adenovirus (HAdV), three viruses associated with corneal infections.

METHODS

Cacicol^® was compared to vehicle in the following viral strains: HSV-1 SC16 strain and HSV-1 PSLR, a clinical isolate highly resistant to acyclovir and foscarnet; VZV ATH and VZV FLO, two VZV clinical isolates; and HAdV-D37 strain. Viruses in Cacicol^® or vehicle were added to cells for 1 h during adsorption then viral replication was assessed by plaque reduction assays on Vero cells for HSV-1 and MeWo cells for VZV and by immunostaining assay on Hep-2 cells for HAdV-D37.

RESULTS

The vehicle had no effect, dose-dependent effects were demonstrated when HSV-1 SC16, HSV-1 PSLR, VZV ATH and VZV FLO were inoculated in the presence of Cacicol^®, inhibiting viral replication by 98.4%, 98.9%, 90.1% and 89.0%, respectively. Cacicol^® had no antiviral effect against HAdV-D37.

CONCLUSIONS

Cacicol^® has a significant antiviral activity on HSV-1 and VZV, but not on HAdV-D37. The lack of effect on HAdV is probably because it is less dependent on HS interactions for cell entry. Clinical studies are necessary to determine Cacicol^® for an adjunct or alternative therapy of corneal HSV-1 or VZV infection, particularly for the management of antiviral resistant HSV-1.

Evaluation of corneal epithelial wound healing after penetrating keratoplasty in patients receiving a new matrix therapy agent (regenerating agent)

OBJECTIVES

Complete epithelial wound healing is a milestone in early postoperative care after penetrating keratoplasty. The re-epithelialization rate after penetrating keratoplasty was measured in patients receiving a new matrix therapy agent (regenerating agent, Cacicol^®) that mimics heparan sulphates.

METHODS

This was a prospective, open-label, uncontrolled, single-centre observational study. A total of 33 consecutive patients (33 eyes) who underwent an 8.25-mm diameter penetrating keratoplasty were treated with regenerating agent eye drops: one drop in the operating theatre immediately after graft, then on alternate days. Patients were divided into those at low risk (13 patients) and high risk (20 patients) of delayed wound healing, and follow-up was performed by digital slit lamp with fluorescein-dye testing repeated daily at a fixed time. Dye area was measured using ImageJ freeware. The main endpoint was epithelial healing after regenerating agent therapy.

RESULTS

The mean ± standard deviation time to complete healing for all patients was 2.7 ± 1.1 (median: 3, range: 1-6) days. This was obtained on Day 1 for 15% of patients, Day 2 for 33%, Day 3 for 88%, Day 4 for 94% and Day 6 for 100%. There was no significant difference between low- and high-risk patients. The area of epithelial defect decreased by a mean ± standard deviation of 75% ± 22% between Day 1 and Day 2, corresponding to a mean ± standard deviation wound-healing rate of 11.5 ± 6.5 mm²/D. There were no systemic or local side effects related to regenerating agent.

CONCLUSION

These preliminary data suggest that regenerating agent could be a useful, non-invasive therapeutic approach in postoperative management of penetrating keratoplasty with the potential to accelerate re-epithelialization.

Corneal epithelial stem cells for corneal injury

INTRODUCTION

Ocular surface diseases with limbal insufficiency represent a therapeutic challenge for restoring vision. This corneal deficiency includes both classical ocular diseases (as chemical burns) and rare ocular diseases (as congenital aniridia and ocular cicatricial pemphigoid).

AREAS COVERED

Our understanding of limbal epithelial stem cells (LESCs) has increased the potential for treatment options. Pharmacological treatment strategies (as regenerating agent ophthalmic solutions) and especially surgical treatment strategies are available. Isolated LESCs can be produced by limbal primary cultures obtained from explants or cell suspensions. We review the latest cornea surgery techniques.

EXPERT OPINION

The adjunction of human limbal mesenchymal cells as a support for limbal stem cell primary cultures appears to be of great interest. Recently, human-induced pluripotent stem cells have allowed the generation of minicorneal organoids. This potential means of creating a three-dimensional cornea with in vitro maturation opens up important research areas for corneal regeneration therapy.

Application of Novel Drugs for Corneal Cell Regeneration

Corneal transplantation has been the only treatment method for corneal blindness, which is the major cause of reversible blindness. However, despite the advancement of surgical techniques for corneal transplantation, demand for the surgery can never be met due to a global shortage of donor cornea. The development of bioengineering and pharmaceutical technology provided us with novel drugs and biomaterials that can be used for innovative treatment methods for corneal diseases. In this review, the authors will discuss the efficacy and safety of pharmacologic therapies, such as Rho-kinase (ROCK) inhibitors, blood-derived products, growth factors, and regenerating agent on corneal cell regeneration. The promising results of these agents suggest that these can be viable options for corneal reconstruction and visual rehabilitation.

Randomized controlled trial demonstrates the benefit of RGTA® based matrix therapy to treat tendinopathies in racing horses

A randomized controlled trial was performed on racing horses, to evaluate the efficacy of a new class of therapeutic agents in regenerative medicine—ReGeneraTing Agents^® (RGTA^®), to treat tendinopathies. Preliminary uncontrolled studies on tendon healing in racing horses with RGTA^® (OTR4131)—Equitend^® showed encouraging results, justifying performing a randomized, controlled, multicenter study with a two-year racing performance follow up. The objective of this study was to evaluate the effect of Equitend^® versus placebo on acute superficial digital flexor tendonitis in racing French Standardbred Trotters (ST). Twenty-two ST were randomly and blindly assigned to receive with a ratio of 2 to 1, a single Equitend^® (n = 14) or placebo (n = 8) intralesional injection under ultrasonographic guidance. Horses were evaluated over 4 months, by clinical and ultrasonographic evaluations (day 0, months 1, 2, 4), and their racing performances followed up over the 2 years after treatment. During the first month of treatment, a significant decrease in the cross-sectional area (CSA) was found in the Equitend^® group (p = 0.04). After 4 months, the number of Equitend^® treated horses with an improved CSA was significantly higher than the placebo-treated horses (p = 0.03571). The Equitend^® group returned to their pre-injury performance level, racing in, and winning, significantly more races than the placebo group (p = 0.01399 and 0.0421, respectively). Furthermore, recurrence was significantly higher in the placebo group than in the Equitend^® group (71.4% vs 16.6%, p = 0.02442). In conclusion, we measured a significant, short-term, reduction effect on CSA and demonstrated a long-term beneficial effect of intralesional injection of Equitend^® for the treatment of superficial digital flexor tendonitis on racing ST, racing 2. 3 times more often than placebo, with 3.3 times fewer recurrences maintaining pre-injury performance level. This study may open the way for the development of a human treatment of tendonitis.

Evaluation of a new matrix regenerating agent in patients with Sjögren syndrome and superficial ulcerative keratitis resistant to conventional therapy: A report of 3 cases

RATIONALE

Sjögren syndrome (SS) is frequently associated with ulcerative keratitis, which is difficult to treat due to lacrimal tear deficiency and inflammation of the ocular surface.

PATIENT CONCERNS

We report the successful additive effect of a matrix regenerating agent (RGTA, Cacicol) in SS patients with severe superficial ulcerative keratitis resistant to conventional therapy.

DIAGNOSES

Retrospective, noncomparative case series of patients with primary or secondary SS associated with chronic diffuse keratitis.

INTERVENTIONS

All patients (3 women, aged 46, 59, and 84 years) had several years of dry-eye disease history and recurrent keratitis despite having used maximal dose topical therapies including artificial tear substitutes, topical vitamin A, and cyclosporine 0.05% emulsion. All patients suffered from dry, diffuse, and chronic superficial keratitis of at least 75% of the corneal surface, with no sign of corneal neovascularization or opacity.

OUTCOMES

RGTA treatment led to a rapid and marked decrease of ocular pain, burning, irritation, foreign body sensation, and improvement of visual acuity. Total diffuse keratitis healing occurred after several months of treatment. Discontinuation of RGTA administration led to the recurrence of severe keratitis; re-introduction of RGTA was successful. No local or systemic adverse effects related to treatment were reported.

LESSONS

RGTA treatment was effective and safe in this small series of 3 patients suffering from SS associated with recurrent or chronic superficial ulcerative keratitis resistant to conventional therapy.

[Frequency of corneal ulcer: Retrospective study of 380 cases carried out in two centers in the DR Congo]

PURPOSE

To determine the frequency of corneal ulcer in our practice environment.

METHODOLOGY

This study was conducted at Saint-Joseph Hospital in Kinshasa and at the Lubumbashi University Clinics in the Democratic Republic of Congo from January 2011 to December 2014. We studied the frequency, demographic and clinical variables of corneal ulcer patients.

RESULTS

A total of 380 cases of corneal ulcers were recorded out of 44,722 ophthalmologic consultations performed, with a frequency of 0.85% and a sex ratio ranging from 1.4 to 1.7 men to women. Corneal ulcer was diagnosed in patients of all ages; the mean age was 38.67±18.67 years. Patients with corneal ulcers presented for eye pain (80%), followed by tearing, photophobia, eye redness and blurred vision. The frequency of visual impairment was 10.30%; 2.1% of patients had vision reduced to light perception, and 1% of patients had no light perception. Corneal dystrophy was present in 41.6% of cases. Perforation of the globe and endophthalmitis were observed in 3.4% of cases each.

CONCLUSION

Corneal ulceration is one of the leading causes of visual impairment and blindness in our practice environment. An early ophthalmologic consultation at the onset of symptoms and adequate management would improve the visual prognosis of patients.

New Therapeutic Perceptions in a Patient with Complicated Herpes Simplex Virus 1 Keratitis: A Case Report and Review of the Literature

Patient: Male, 80

Final Diagnosis: Unilateral complicated Herpetic Simplex Virus 1 Keratitis

Symptoms: Visual impairment

Medication: Anti-herpetic treatment • Anti-VEGF • Cyclosporine A • Matrix regeneration therapy

Clinical Procedure: Amniotic membrane and limbal stem cell transplantation

Specialty: Ophthalmology

Matrix regeneration agents improve wound healing in non-stressed human corneal epithelial cells

PurposeMatrix regenerating agents (RGTAs) emerged as promising in vivo wound-healing agents. These agents could prove beneficial for the treatment of dry eye disease-associated corneal micro-erosions; therefore, we aimed to evaluate the wound healing efficacy of regenerative agents (RGTAs or serum) in an in vitro model of hyperosmolarity (HO) stressed and non-stressed human corneal epithelial cells.Patients and methodsThe migration and proliferation induced by the regenerative agents was evaluated using an in vitro scratch wound assay and brome-deoxy-uridine incorporation. The inflammatory profile and effects of osmoregulators were also investigated. The two-tailed paired t-test calculated the statistical significance, with P-value<0.05 considered significant.ResultsThe most efficient inducer of re-epithelization was 2% serum, followed closely by 2% RGTA with an average improvement in cell migration of 1.8- and 1.4-fold, respectively, when compared with the non-treated control. Hyperosmolar stress significantly reduced the restorative effects of both serum and RGTAs; these effects were, however, neutralized by the osmoregulator betaine.ConclusionThese findings suggest that RGTAs could provide efficient treatment for dry-eye associated corneal micro-lesions if ocular surface HO is neutralized.

Matrix regenerative therapy

The extracellular matrix (ECM) is responsible for many of the cell behavior processes, including cell proliferation and growth, survival, change in cell shape, migration, and differentiation. The most important component of the ECM is heparan sulfate (HS), because it insures the storage of many cell communication proteins, necessary for the continuous and identical renewal of cells and thus for tissue regeneration. Regenerating agents (RGTA®) are bioengineered structural analogues of heparan sulfate glycosaminoglycans that replace the degraded endogenous HS of the ECM. In the ophthalmological field, RGTA® represents an innovative approach for the improvement of the ocular surface wound healing and matrix remodeling and plays a role in controlling and regulating the wound healing process in various ocular diseases.

RGTA® or ReGeneraTing Agents mimic heparan sulfate in regenerative medicine: from concept to curing patients

The importance of extracellular matrix (ECM) integrity in maintaining normal tissue function is highlighted by numerous pathologies and situations of acute and chronic injury associated with dysregulation or destruction of ECM components. Heparan sulfate (HS) is a key component of the ECM, where it fulfils important functions associated with tissue homeostasis. Its degradation following tissue injury disrupts this delicate equilibrium and may impair the wound healing process. ReGeneraTing Agents (RGTA^®s) are polysaccharides specifically designed to replace degraded HS in injured tissues. The unique properties of RGTA^® (resistance to degradation, binding and protection of ECM structural and signaling proteins, like HS) permit the reconstruction of the ECM, restoring both structural and biochemical functions to this essential substrate, and facilitating the processes of tissue repair and regeneration. Here, we review 25 years of research surrounding this HS mimic, supporting the mode of action, pre-clinical studies and therapeutic efficacy of RGTA^® in the clinic, and discuss the potential of RGTA^® in new branches of regenerative medicine.

Treatment of Acanthamoeba neurotrophic corneal ulcer with topical matrix therapy

Background

This study was done to evaluate the visual and anatomical outcomes of topical regenerating agents as a novel therapy for neutrophic corneal ulcer (NCU) secondary to acanthamoeba infection.

Findings

A 20-year-old woman with a history of contact lens wear was referred to our hospital for keratitis after responding poorly to conventional treatment. In vivo confocal microscopy images suggested acanthamoeba keratitis with double-walled cysts in the anterior corneal stroma. Acanthamoeba infection was confirmed by laboratory findings. She was started on 0.1 % propamidine and 0.02 % chlorhexidine drops every hour. The antibiotic and antifungal drops were stopped when bacterial and fungal cultures proved negative. A central neurotrophic corneal ulcers (NCU) appeared, and despite treatment with artificial tears, bandage contact lens, and autologous serum, the ulcer worsened and she was treated with topical CACICOL20 (1 drop every 2 days) for 8 weeks. The corneal defect was completely repaired in 3 weeks. The treatment was well tolerated, and no local or systemic side effects were noted. Visual acuity remained 20/400. Two months later, the defect was still closed and the patient continued with 0.1 % propamidine and 0.02 % chlorhexidine drops, bandage contact lens, artificial tears, and autologous serum.

Conclusions

Topical regenerating agents interact with components of the extracellular matrix, binding matrix proteins and protecting them from proteolysis, restoring the matrix environment, and improving tissue healing. In this case, CALCICOL20 was effective for vision stabilization, wound healing, and was well tolerated for NCU secondary to acanthamoeba infection.

Sclerokeratoplasty as the Therapy for Corneal Perforation due to Exposure and Neurotrophic Keratopathy

A case report of exposure and neurotrophic keratopathy after acoustic neuroma surgery resulting in perforation if not managed appropriately and timely is presented. Sclerokeratoplasty on 360 degrees may be an effective treatment method of corneal perforation in complete anaesthetic cornea when the standard penetrating keratoplasty failed. At a 12-month follow-up, the patient is doing well. UCVA is 0.5, the IOP is normal, and the graft remains clear. Systemic immunosuppression is the main disadvantage of this method. Further investigation is needed to assess the effectiveness and safety of this method.

Glycosaminoglycan mimetic associated to human mesenchymal stem cell-based scaffolds inhibit ectopic bone formation, but induce angiogenesis in vivo

Tissue engineering approaches to stimulate bone formation currently combine bioactive scaffolds with osteocompetent human mesenchymal stem cells (hMSC). Moreover, osteogenic and angiogenic factors are required to promote differentiation and survival of hMSC through improved vascularization through the damaged extracellular matrix (ECM). Glycosaminoglycans (GAGs) are ECM compounds acting as modulators of heparin-binding protein activities during bone development and regenerative processes. GAG mimetics have been proposed as ECM stabilizers and were previously described for their positive effects on bone formation and angiogenesis after local treatment. Here, we developed a strategy associating the GAG mimetic [OTR4120] with bone substitutes to optimize stem cell-based therapeutic products. We showed that [OTR4120] was able to potentiate proliferation, migration, and osteogenic differentiation of hMSC in vitro. Its link to tricalcium phosphate/hydroxyapatite scaffolds improved their colonization by hMSC. Surprisingly, when these combinations were tested in an ectopic model of bone formation in immunodeficient mice, the GAG mimetics inhibit bone formation induced by hMSC and promoted an osteoclastic activity. Moreover, the inflammatory response was modulated, and the peri-implant vascularization stimulated. All together, these findings further support the ability of GAG mimetics to organize the local ECM to coordinate the host response toward the implanted biomaterial, and to inhibit the abnormal bone formation process on a subcutaneous ectopic site.

RGTA-based matrix therapy in severe experimental corneal lesions: safety and efficacy studies

Corneal alteration potentially leading to ulceration remains a major health concern in ocular surface diseases. A treatment that would improve both the quality and speed of healing and control the inflammation would be of great interest. Regenerating agents (RGTAs) have been shown to stimulate wound healing and modulate undesired fibrosis in various in vivo systems. We investigated the effects of RGTA-OTR4120(®) in a rabbit corneal model in order to assess its potential use in ocular surface diseases. First, we assessed its safety for 7 and 28 days using the Draize test criteria in healthy rabbit eyes; then, we investigated the effect of a single dose (50μl, 5μg) in an alkali-burned cornea model. Daily follow-up of clinical signs of healing was scored, and histology was performed at D7. RGTA was well tolerated; no signs of ocular irritation were observed. In the corneal alkali-burn model, non-RGTA-treated eyes showed inflammatory clinical signs, and histology confirmed a loss of superficial corneal layers with epithelial disorganization, neovascularization and infiltration of inflammatory cells. When compared to NaCl control, RGTA treatment appeared effective in reducing clinical signs of inflammation, enhancing re-epithelialization, and improving histological patterns: edema, fibrosis, neovascularization and inflammation. Three to four layers of epithelial cells were already organized, stroma was virtually unvascularized and keratocytes well implanted in parallel collagen fibers with an overall reorganization similar to normal cornea. RGTA appears to be a promising agent for controlling ocular surface inflammation and promoting corneal healing and was well tolerated. This study offers preclinical information and supports the findings of other (compassionate or pilot) studies conducted in patients with various ocular surface diseases.

[Management of herpes zoster neurotrophic ulcer using a new matrix therapy agent (RGTA): A case report]

Neurotrophic keratopathy is a potential consequence of herpes simplex virus (HSV) or varicella zoster virus (VZV) infection. The treatment is based on artificial tears and the withdrawal of preserved eye drops or other types of epitheliotoxic topical medicines. Autologous serum or amniotic membrane transplantation may also be used in severe cases, but their cost and safety are still under debate. We report a case of a patient with a history of herpes zoster ophthalmicus, who developed a persistent epithelial ulcer after cataract surgery, with no improvement despite 3 weeks of artificial tears (eight drops per day). A new ophthalmologic solution based on a regenerating agent (RGTA, Cacicol20(®)) was then used, with a dosage of two eye drops per week for 6 weeks. Improvement was observed 1 week later, and complete healing was obtained in less than 3 weeks, with no side effects. This heparin mimetic, which may stimulate extracellular matrix healing, may be a possible alternative therapy to autologous serum or amniotic membrane transplantation in severe neurotrophic ulcer. However, randomized studies are necessary to validate this observation.

Regenerating matrix-based therapy for chronic wound healing: a prospective within-subject pilot study

The aim of this study was to determine whether a skin-specific bioengineered regenerating agent (RGTA) heparan sulphate mimetic (CACIPLIQ20) improves chronic wound healing. The design of this article is a prospective within-subject study. The setting was an urban hospital. Patients were 16 African-American individuals (mean age 42 years) with 22 wounds (mean duration 2.5 years) because of either pressure, diabetic, vascular or burn wounds. Two participants each were lost to follow-up or removed because of poor compliance, resulting in 18 wounds analysed. Sterile gauze was soaked with CACIPLIQ20 saline solution, placed on the wound for 5 min, then removed twice weekly for 4 weeks. Wounds were otherwise treated according to the standard of care. Twenty-two percent of wounds fully healed during the treatment period. Wounds showed a 15.2-18.1% decrease in wound size as measured by the vision engineering research group (VERG) digital wound measurement system and total PUSH scores, respectively, at 4 weeks (P = 0.014 and P = 0.003). At 8 weeks there was an 18-26% reduction in wound size (P = 0.04) in the remaining patients. Wound-related pain measured by the visual analogue pain scale and the wound pain scale declined 60% (P = 0.024) and 70% (P = 0.001), respectively. Patient and clinician satisfaction remained positive throughout the treatment period. It is concluded that treatment with CACIPLIQ20 significantly improved wound-related pain and may facilitate wound healing. Patient and clinician satisfaction remained high throughout the trial.

Stimulated neovascularization, inflammation resolution and collagen maturation in healing rat cutaneous wounds by a heparan sulfate glycosaminoglycan mimetic, OTR4120

Heparan sulfate glycosaminoglycans (HS-GAGs) are not only the structural elements of tissue architecture but also regulate the bioavailability and transduction pathways of heparan sulfate-bound polypeptides released by cells or the extracellular matrix. Heparan sulfate-bound polypeptides include inflammatory mediators, chemokines, angiogenic factors, morphogens, and growth-promoting factors that induce cell migration, proliferation, and differentiation in wound healing. OTR4120, a polymer engineered to mimic the properties of HS-GAGs, is used to replace the natural HS-GAGs that are degraded during wound repair, and enhance the tissue regeneration by preserving the cellular microenvironment and the endogenous signals needed for tissue regeneration. We previously demonstrated that OTR4120 treatment had a long-term effect on increasing breaking strength and vasodilation in healing rat full-thickness excisional wounds. The present study investigates the underlying mechanisms of the effects of OTR4120 treatment in improving the quality of cutaneous wound repair. We found that OTR4120 treatment stimulated inflammation resolution and increased neovascularization. OTR4120 treatment also promoted epidermal migration and proliferation during reepithelialization. Moreover, the granulation tissue formation and collagen maturation were improved in OTR4120-treated wounds. Three months after wounding, the effects of OTR4120 treatment on vascularization and inflammation resolution were normalized, except for an improved neodermis. We conclude that OTR4120 is a potential matrix therapeutic agent that ensures the quality of normal cutaneous wound repair and may restore impaired wound healing characterized by deficient angiogenesis and prolonged inflammation.