Current understanding and review of the literature: vocal fold scarring

Vocal fold scarring is the greatest cause of poor voice after vocal fold injury. Scarring causes a disruption of the viscoelastic layered structure of the lamina propria, an increase in stiffness of the vibratory structure, and glottic incompetence. Current treatments for this complex condition are inconsistent and often produce suboptimal results. Research investigating this condition has dramatically increased over the last several years. The literature has been directed toward understanding vocal fold scarring at the biological level and translating this to the clinical forum. We present an up-to-date, thorough, and scholarly review of the literature in vocal fold scarring since 1996.

First experiences with the collagen-elastin matrix Matriderm as a dermal substitute in severe burn injuries of the hand

Restoring function after hand burns plays a major role in the restitution of a quality of life. Thereby the reconstructed pliability of the grafted areas is of utmost importance for good hand function. The collagen elastin matrix Matriderm was evaluated as a dermal substitute for the treatment of severe hand burns. In a series of 10 patients, mean age 43 years, TBSA 22.8%, an early debridement and immediate grafting with the matrix and unmeshed skin graft was carried out in a one-stage procedure. In the early postoperative follow up an overall take rate of 97% was observed. In contrast to conventional skin grafts, the color of the skin grafts over the matrix appeared pale in the first few days, but after 2 weeks no difference was observed. After three months, pliability of the grafted area was excellent, (mean VSS 3.2+/-1.2). Full range of motion was achieved in all hands, no blisters and no unstable or hypertrophic scars occurred. Matriderm has proved to be a dermal substitute suitable for the treatment of hand burns. We therefore consider Matriderm as a promising dermal substitute for the treatment of severe hand burns.

Injectable biomaterials and vertebral endplate treatment for repair and regeneration of the intervertebral disc

The objectives of augmentation of the nucleus pulposus following disc removal are to prevent disc height loss and the associated biomechanical and biochemical changes. Flowable materials may be injected via a small incision, allowing minimally invasive access to the disc space. Fluids can interdigitate with the irregular surgical defects and may even physically bond to the adjacent tissue. Injectable biomaterials allow for incorporation and uniform dispersion of cells and/or therapeutic agents. Injectable biomaterials have been developed that may act as a substitute for the disc nucleus pulposus. Our work has focused on the evaluation of a recombinant protein copolymer consisting of amino acid sequence blocks derived from silk and elastin structural proteins as an injectable biomaterial for augmentation of the nucleus pulposus. This implant, NuCoretrade mark Injectable Nucleus is being developed by Spine Wave (Shelton, CT). The NuCoretrade mark material is comprised of a solution of the protein polymer and a polyfunctional cross-linking agent. The material closely mimics the protein content, water content, pH and complex modulus of the natural nucleus pulposus. Extensive mechanical testing, biocompatibility and toxicology testing have been performed on the material. Characterization studies indicate that the NuCoretrade mark Injectable Nucleus is able to restore the biomechanics of the disc following a microdiscectomy. Extensive biomaterial characterization shows the material to be non-toxic and biocompatible. The mechanical properties of the material mimic those of the natural nucleus pulposus. Thus NuCoretrade mark Injectable Nucleus is suitable to replace the natural nucleus pulposus following a discectomy procedure. Human clinical evaluation is underway in a multi center clinical study on the use of the material as an adjunct to microdiscectomy. Further clinical studies of the use of NuCoretrade mark Injectable Nucleus for treatment of early stage degenerative disc disease are planned in the near future. On-going efforts are characterizing the use of the material as a cell delivery vehicle for disc repair and reconstruction. Related development efforts are exploring methods for repair and regeneration of the cartilage endplate that are implemented to enhance the host-implant interface. Prior to the introduction of the above-mentioned biomaterial, our work proposes to utilize a process for the treatment of the vertebral endplates. The goal of this process is to restore the endplates as closely as possible to their natural state prior to disease or degeneration. The nature of the treatment will depend upon the form of the endplate degeneration and on the type of scaffolding that is intended to be introduced in the nuclear cavity. Endplate therapy is a potential means of enhancing biomaterial integration and cell survival, but remains a long-term and currently untested methodology.

First steps towards tissue engineering of small-diameter blood vessels: preparation of flat scaffolds of collagen and elastin by means of freeze drying

Porous scaffolds composed of collagen or collagen and elastin were prepared by freeze drying at temperatures between -18 and -196 degrees C. All scaffolds had a porosity of 90-98% and a homogeneous distribution of pores. Freeze drying at -18 degrees C afforded collagen and collagen/elastin matrices with average pore sizes of 340 and 130 mum, respectively. After 20 successive cycles up to 10% of strain, collagen/elastin dense films had a total degree of strain recovery of 70% +/- 5%, which was higher than that of collagen films (42% +/- 6%). Crosslinking of collagen/elastin matrices either in water or ethanol/water (40% v/v) was carried out using a carbodiimide (N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, EDC) in combination with a succinimide (N-hydroxysuccinimide, NHS) in the presence or absence of a diamine (J230) or by reaction with butanediol diglycidylether (BDGE), followed by EDC/NHS. Crosslinking with EDC/NHS or EDC/NHS/J230 resulted in matrices with increased stiffness as compared to noncrosslinked matrices, whereas sequential crosslinking with the diglycidylether and EDC/NHS yielded very brittle scaffolds. Ethanol/water was the preferred solvent in the crosslinking process because of its ability to preserve the open porous structure during crosslinking. Smooth muscle cells were seeded on the (crosslinked) scaffolds and could be expanded during 14 days of culturing.

Binding of elastin peptides to S-Gal protects the heart against ischemia/reperfusion injury by triggering the RISK pathway

Elastin peptides (EPs) generated by hydrolysis of elastic fibers by elastinolytic enzymes display a wide spectrum of biological activities. Here, we investigated their influence on rat heart ischemia-mediated injury using the Langendorff ex vivo model. EPs, i.e., kappa elastin, at 1.32- and 660-nM concentrations, when administered before the ischemia period, elicited a beneficial influence against ischemia by accelerating the recovery rate of heart contractile parameters and by decreasing significantly creatine kinase release and heart necrosis area when measured at the onset of the reperfusion. All effects were S-Gal-dependent, as being reproduced by (VGVAPG)3 and as being inhibited by receptor antagonists, such as lactose and V14 peptide (VVGSPSAQDEASPL). EPs interaction with S-Gal triggered NO release and activation of PI3-kinase/Akt and ERK1/2 in human coronary endothelial cells (HCAECs) and rat neonatal cardiomyocytes (RCs). This signaling pathway, as designated as RISK, for reperfusion injury salvage kinase pathway, was shown to be responsible for the beneficial influence of EPs on ischemia/reperfusion injury on the basis of its inhibition by specific pharmacological inhibitors. EPs survival activity was attained at a concentration averaging that present into the blood circulation, supporting the contention that these matrikines might offer a natural protection against cardiac injury in young and adult individuals. Such protective effect might be lost with aging, since we found that hearts from 24-month-old rats did not respond to EPs.

The use of Matriderm and autologous skin grafting in the treatment of diabetic ulcers: a case report

The aim of our case report was to analyse the results obtained with the Matriderm system and autologous skin grafting for the surgical treatment of diabetic ulcers. We recruited one patient with diabetic ulcers admitted at the Department of Plastic and Reconstructive Surgery, University of Rome 'Tor Vergata'. The patient underwent Matriderm system and autologous skin grafting for diabetic ulcer treatment. After just a single treatment, we obtained reduction in ulcer after 15 days from the surgical treatment. We achieved a reduction in pain and exudate secretion of the ulcer. We noticed an almost complete restoration of the missing volume and good quality of skin. Matriderm system and autologous skin grafting is a simple, safe and feasible technique. This method, when compared with other methods of treatment, is simple, cheap, less time consuming and does not require sophisticated laboratory facilities.

Genetic approaches to disease and regeneration

Cardiovascular disease is largely a consequence of coronary artery blockage through excessive proliferation of smooth muscle cells. It in turn leads to myocardial infarction and permanent and functionally devastating tissue damage to the heart wall. Our studies have revealed that elastin is a primary player in maintaining vascular smooth muscle cells in their dormant state and thus may be a useful therapeutic in vascular disease. By studying zebrafish, which unlike humans, can repair damage to heart muscle, we have begun to uncover some of the genes that seem necessary to undertake the de-differentiation steps that currently fail and prevent the formation of new proliferating cardiomyocytes at the site of damage in a mammalian heart.

Self-Assembly of Thermoresponsive Recombinant Silk-Elastinlike Nanogels

Recombinant silk-elastinlike protein polymers (SELPs) combine the biocompatibility and thermoresponsiveness of human tropoelastin with the strength of silk. Direct control over structure of these monodisperse polymers allows for precise correlation of structure with function. This work describes the fabrication of the first SELP nanogels and evaluation of their physicochemical properties and thermoresponsiveness. Self-assembly of dilute concentrations of SELPs results in nanogels with enhanced stability over micelles due to physically crosslinked beta-sheet silk segments. The nanogels respond to thermal stimuli via size changes and aggregation. Modifying the ratio and sequence of silk to elastin in the polymer backbone results in alterations in critical gel formation concentration, stability, aggregation, size contraction temperature, and thermal reversibility. The nanogels sequester hydrophobic compounds and show promise in delivery of bioactive agents.

Nanotoxicology of an Elastin-like Polypeptide Rapamycin Formulation for Breast Cancer

The clinical utility of rapamycin (Rapa) is limited by solubility, bioavailability, and side effects. To overcome this, our team recently reported an elastin-like polypeptide (ELP) nanoparticle with high affinity, noncovalent drug binding, and integrin-mediated cellular uptake. Given the scarcity of pharmacology/toxicology studies of ELP-based drug carriers, this article explores safety and efficacy of ELP-Rapa. ELP-Rapa nanoparticles tested negative for hemolysis, did not interfere in plasma coagulation nor in platelet function, and did not activate the complement. Upon incubation with HepG2 cells, ELP-Rapa revealed significant cellular uptake and trafficking to acidic organelles, consistent with lysosomes. Internalized ELP-Rapa nanoparticles increased oxidative stress 4-fold compared to free drug or free ELP controls. However, mice bearing orthotopic hormone receptor positive BT-474 breast tumors, given a high dose (∼10-fold above therapeutic dose) of 1 month administration of ELP-Rapa, did not induce hepatotoxicity. On the other hand, tumor growth and mTOR signaling were suppressed without affecting body weight. Nanoparticles assembled using ELP technology appear to be a safe and efficient strategy for delivering Rapa.

Laser-assisted vascular end to end anastomosis of elastin heterograft to carotid artery with an albumin stent: A preliminary in vivo study

BACKGROUND AND OBJECTIVES

Laser-assisted end to end vascular anastomosis of an elastin heterograft to native artery may prevent problems associated with currently available vascular synthetic grafts and conventional suture anastomosis.

STUDY DESIGN/MATERIALS AND METHODS

A total of 21 anastomoses in the carotid arteries of 7 domestic swine were performed with an 800 nm laser and an albumin stent plus solder. There were 5 artery to artery and 16 elastin heterograft to native artery anastomoses. Operative parameters, vascular patency, and histology of the anastomoses were evaluated.

RESULTS

Out of 21 anastomoses, 16 were patent for 3 hours. One artery to artery anastomosis was thrombosed and four elastin heterograft to artery anastomoses were excluded from the study due to heterograft burst. The average amount of applied energy was 212 J for artery to artery anastomosis and 273 J for elastin heterograft to native artery. Histology shows coagulative necrosis of the adventitia, hypereosinophilic contraction band in the media of native arteries and no changes in elastin heterografts.

CONCLUSIONS

Laser-assisted vascular anastomosis (LAVA) of elastin heterograft to medium size vessel using an albumin stent is feasible. Chronic studies are warranted to determine long-term patency and histology of the LAVA.

Application of coacervated alpha-elastin to arterial prostheses for inhibition of anastomotic intimal hyperplasia

Prevention of anastomotic intimal hyperplasia (AIH) requires inhibition of the migration of smooth muscle cells (SMCs) and promotion of endothelial cell (ECs) growth from the native arterial wall. We investigated the effect of coacervated alpha-elastin on migration of SMCs and ECs in vitro. SMCs and ECs were prepared from porcine aortic media and endothelium. Coacervated alpha-elastin was coated and cross-linked around the perimeter of each 1 cm diameter center of a well in a 12 well plate. SMCs and ECs were placed and cultured within the center of each well. The migration of SMCs and ECs on coacervated alpha-elastin was assayed on the second, third (10 mg/ml), or fourth day (0.1, 1.0, 10.0 mg/ml) of cultivation by measuring the area of migration from the 1 cm diameter center. Coacervated alpha-elastin was then coated and cross-linked on a Dacron graft using 1% glycerol polyglycidyl ether (GPGE) and examined with scanning electron microscopy to determine the feasibility of graft coating. SMC migration was significantly inhibited dose dependently over time (p < 0.005), e.g., 0.1 mg/ml (45.4% +/- 2.7%: % of MES [pH 5] and 1% GPGE without alpha-elastin), 1.0 mg/ml (32.0% +/- 1.4%), 10.0 mg/ml (8.3% +/- 2.9%). EC migration (90.7% +/- 6.2%: p = ns) was not inhibited by 0.1 mg/ml of coacervated alpha-elastin. Cross-linked coacervated alpha-elastin was coated on a dacron graft uniformly. Incorporation of coacervated alpha-elastin into the structure of arterial prostheses offers the possibility of inhibition of SMC hyperplasia without inhibition of EC formation.

A new biodegradable elastin-fibrin material; its use in urological, digestive and cardiovascular surgery

A new original artificial connective matrix mainly made of elastin and fibrin-like product is used to reinforce damaged tissues and to close and restore a loss of substance in several domains of surgery: all sites in the digestive system and urinary tract; besides, it can substitute for the pericardium in iterative heart operations. In all cases, the original tissue is restored ad integrum while the biodegradable material disappears completely, without any complications.

Laser-Assisted End-to-End Vascular Anastomosis of Elastin Heterograft to Carotid Artery with an Albumin Stent in Vivo

BACKGROUND DATA

Laser-assisted end-to-end vascular anastomosis of an elastin heterograft to native artery may avoid the problems associated with currently available vascular synthetic grafts and conventional suture anastomosis.

METHODS

A total of 21 anastomoses in the carotid arteries of seven domestic pigs were performed with an 800-nm laser and an albumin stent plus solder. There were five artery to artery and 16 elastin heterograft to native artery anastomoses. Operative parameters, vascular patency, and histology of the anastomoses were evaluated.

RESULTS

Out of 21 anastomoses, 20 were patent at 3 h. The average amount of total energy used was 212 Joules in artery to artery anastomosis and 273 Joules in elastin heterograft to native artery. Histology shows coagulative necrosis of the adventitia, hypereosinophilic contraction band in the media in native artery, and no change in elastin heterografts.

CONCLUSIONS

Laser-assisted vascular anastomosis of elastin heterograft to medium size vessel is possible. Albumin stent played an important role in strength of the anastomosis. Chronic studies are warranted to determine long-term patency and histology of the laser-assisted vascular anastomosis.

Biomarine extracts significantly protect from ultraviolet A-induced skin photoaging: an ex vivo study

We tested the activity of the marine nutraceutical CL-1222 added with a coenzyme Q10 (CoQ10)-lutein-selenium component (Celergen(®), Laboratoires-Dom, Switzerland) to protect human fibroblasts against ultraviolet A (UVA)-induced photoaging. Cells obtained from 22- to 39-year-old healthy donors were pretreated with CL-1222 before UV irradiation, as compared with same quantity of the CoQ10-lutein-selenium component. As compared to untreated control, UVA-irradiated samples exhibited a significant increase of secreted matrix metalloproteinase-1 (MMP-1) (p<0.001) with over four-fold MMP-1 upregulation (p<0.001). Samples treated with CL-1222, but not with the CoQ10-lutein-selenium component, showed a significant decrease of MMP-1 secretion (p<0.01) and expression decrease (>60%, p<0.01) with >54% elastase activity inhibition (p<0.01). This preliminary study shows that such marine nutraceuticals can significantly protect against UV-irradiation irrespective of the CoQ10-lutein-selenium component with a specific protective gene expression modulation amenable to novel clinical applications.

A prospective multicenter phase III clinical trial evaluating the efficacy and safety of silk elastin sponge in patients with skin defects

Silk elastin sponge, a novel recombinant protein used for wound healing, has been shown to be effective in promoting macrophage migration, epithelial growth, granulation, and angiogenesis in both preclinical (in vitro and in vivo) and clinical studies. This study aimed to evaluate the efficacy and safety of silk elastin sponges in the treatment of chronic and acute wounds. A prospective multicenter, single-arm, uncontrolled clinical trial included 20 patients with chronic wounds and five with acute wounds, applying the sponge after debridement. The primary endpoints were the percentage of patients with chronic wounds and well-prepared wound beds after 14 days of treatment. The safety of the procedure was also assessed. The results showed that 90.0% of chronic wound patients had well-prepared wound beds by day 14, and 24 out of 25 patients completed the treatment, with one case discontinued due to local infection. This study concluded that silk elastin sponges may be an effective new option for wounds that are unresponsive to existing treatments.Trial registration: jRCT2052210072. Registered on 11 July 2023 in the Japan Registry of Clinical Trials ( http://jrct.niph.go.jp ).

Use of a collagen-elastin matrix with split-thickness skin graft for defect coverage in complex wounds

OBJECTIVE

Severe soft tissue damage with destruction of the dermis requires plastic reconstructive treatment. For multimorbid patients or patients unable to undergo major reconstructive surgery, use of dermal substitutes, such as a collagen-elastin matrix (CEM) with a split-thickness skin graft (STSG), instead of local or free flap surgery, may be a valid and easy treatment option. We aimed to investigate and compare the outcomes and rate of successful defect reconstruction using CEM plus STSG, using either a one-step approach (simultaneous CEM and STSG) or a two-step approach (CEM and negative wound pressure therapy (NPWT), with secondary STSG transplantation).

METHOD

A single-centre, retrospective follow-up study of patients who had received CEM was conducted. Wounds had been treated with an STSG transplantation covering a CEM (MatriDerm, MedSkin Solutions Dr. Suwelack AG, Germany). Previous attempts at wound closure with conventional methods had failed in the selected patient population, which would usually have resulted in flap surgery.

RESULTS

Overall, 46 patients were included (mean age 60.9±20.0 years), with a total of 49 wound sites. We analysed 38 patients with wounds that did not require flap coverage; 18 patients received the one-step approach and 20 patients received the two-step approach. The mean follow-up in these patients was 22±11.5 months, and one patient was lost to follow-up. Overall, 29 (78.4%) wounds remained closed. Wounds which did not successfully heal were related to comorbidities, such as diabetes, alcohol misuse and smoking. Using the one-step approach, long-term defect coverage was achieved in 13 (76.5%) wounds and 16 (80.0%) wounds were closed using the two-step approach. However, there was no statistically significant differences between the one- or two-step approaches regarding the rate of development of a wound healing disorder.

CONCLUSION

Wound closure was achieved in 38 complex wounds using CEM plus STSG, while 11 wounds needed secondary flap coverage. In the flap-free wounds, there were no statistically significant differences between the one-step versus two-step approach. Using a simple defect reconstruction algorithm, we successfully used CEM plus STSG to treat complex wounds.

DERMAL REPLACEMENT WITH MATRIDERM - FIRST EXPERIENCE AT THE PRAGUE BURN CENTRE

INTRODUCTION

The quality of resulting scar tissue plays an important role in patients return to normal life and full functioning in society. The use of artificial skin substitutes in clinical practice improves functional and cosmetic outcomes. This is true for any patient, and not only those suffering from burns.

MATERIAL AND METHODS

The collagen elastin dermal substitute Matriderm® allows for immediate application of a dermal substitute together with a skin graft. The authors present a group of 10 patients representing their first experience in utilizing Matriderm® as a dermal substitute in the treatment of skin losses due to various etiologies.

RESULTS

The average healing time in the group was 19.6 days. Healing took place without serious infectious complications and with good functional results.

CONCLUSION

Matriderm® can be utilized as an alternative to the most commonly used dermal substitute so far, Integra®, in the treatment of acute skin loss due to various etiologies and in reconstructive surgery.

Engineered elastin-like polypeptide-based hydrogel delivering chemotherapeutics and PD-L1 antibodies for potentiated cancer immunotherapy

Immune checkpoint inhibitors (ICIs) have effectively eradicated advanced tumors by inducing durable and systematic antitumor immune responses. However, when used as a standalone treatment, ICIs typically exhibit a low response rate in many cancers. In this study, we engineered an in situ-formed gel depot using elastin-like polypeptides (ELPs) to efficiently deliver PD-L1 antibodies (aPD-L1) and gemcitabine (GEM) for enhanced immunotherapy in melanoma. Sustainably released chemotherapeutics from gel depots could kill melanoma cells and promote PD-L1 upregulation in tumor cells. Moreover, aPD-L1/GEM-encapsulated ELP hydrogel promoted a 3.0-fold increase of tumor-infiltrated CD8+ T cells and 60% Tregs depletion compared with PBS group, eliciting a robust antitumor immune response for immunotherapy in melanoma mouse models. This research highlights the promising potential of ELP-based hydrogels in delivering ICIs and chemotherapeutic agents for potentiated cancer immunotherapy.

[Preliminary results of the evaluation of the Endopatch E-F in digestive surgery]

Endopatch E-F is a new product elaborated with natural human and animal proteins. Its synthesis originates in a covalent link between elastin and fibrin monomers. Numerous experimental studies carried out in animal have previously shown its ability to reinforce healing process of digestive wall. The results reported herein have been obtained in very selected patients in whom a digestive anastomosis had to be done in spite of unfavorable circumstances, such as intra-abdominal infection, radiated bowel or ascitis. From October 1990 to October 1992, 21 digestive anastomosis have been performed in 18 patients. All were reinforced by Endopatch E-F. Two deaths have been observed (mortality: 11.1%), which do not look like a consequence of the use of the product (One myocardial infarction and one cirrhotic failure). There were 2 post-operative fistulas (9.5% of the whole anastomosis). No patients had any reaction of intolerance. These preliminary results confirm experimental data, and suggest that Endopatch EF can be used in order to reinforce digestive sutures when performed under unfavorable circumstances.

Efficacy of collagen and elastin matrix in the treatment of complex lower extremity wounds

Successful engraftment of skin grafts highly depends on the quality of the wound bed. Good quality of blood vessels near the surface is critical to support the viability of the graft. Ischemic, irradiated scar tissue, bone and tendons will not have the sufficient blood supply. In such situations flaps are to be resorted. However, the flaps also need to have good vascularity over the limbs. The introduction of dermal substitutes has provided a novel method for repairing various severe skin defects. These substitutes act as dermal regenerative templates, which facilitate dermal reconstruction and regeneration. This study was done to ascertain the effectiveness of these substitutes in the treatment of complex wounds. Between January 2022 and June 2023, 20 patients who had complex wounds, which could not be treated with simple skin grafting and who were treated with collagen and elastin matrix and split skin grafting (SSG) were retrospectively studied. The percentage of SSG take as per the records was noted at a 10-day post-operative period. Patient characteristics, comorbidities, duration and outcomes of the treatment were noted. Twenty patients were included in the study. The minimum size of the ulcer was 5 × 4 cm (area of 20 cm2) and the maximum size of the ulcer was 15 × 15 cm (225 cm2). Average take of skin graft was 93.7% at 10th post-operative day. Recurrence at 6 months was nil. The scar quality was assessed by patient and observer at 3 months and 6 months post-operatively. The lower-limb ulcers with compromised surrounding tissue are complex. The major goal in these cases is to do simple surgery and prevent recurrence. The collagen and elastin matrices provide structural support for cellular infiltration, which helps maximize a SSG take and a stable long-term scar.

Regression of calcinosis cutis after inkless tattoo in a patient with dermatomyositis: therapeutic potential of microneedling

Calcinosis cutis is defined as abnormal deposition of calcium salts in the skin and subcutaneous tissues. Dystrophic calcification, the most common form of calcinosis cutis, is associated with autoimmune connective tissue diseases. This condition is associated with severe pain and can affect the patient's quality of life and lead to long-term disability. Treatment is often challenging, and there is a very limited evidence base for potential treatments of calcinosis cutis associated with systemic sclerosis and dermatomyositis. Inkless tattoo is very similar to microneedling, a minimally invasive procedure stimulating the wound-healing cascade contributing to elastin and collagen formation as well as neovascularization. This technique has not been reported as a potential therapeutic option for calcinosis cutis. Here, we present a patient with calcinosis cutis in the setting of dermatomyositis that responded dramatically to inkless tattoo application. Our results support the need for future studies of microneedling in patients with this disorder.

A Collagen-Elastin Regenerative Dermal Matrix May Generate Unfavorable Results in Head and Neck Postburn Scar Reconstruction: A Case Series

Background and Objectives: Dermal matrices have brought solutions for many problems, mainly in the treatment of burns and burn scar revisions. The objective of this study was to draw attention to the limits of a collagen-elastin dermal matrix (MatriDerm®) in its 1 mm variant for the treatment of burn scars on the face and neck. Materials and Methods: A case series of four patients (three women and one man) with burn scars of the face (one case) and of the neck (three cases) treated with collagen-elastin matrices is presented. In all cases, the excision or release of the scars was performed, and the defects were covered with MatriDerm® and thin split-thickness skin grafts in the same operative time. Results: In all cases, the graft take was very good but was followed by the important contraction of the graft to such an extent that the results were found to be poor by both the surgeons and the patients. The surface of the new scar was irregular, and the elasticity was low. The article points out some probable causes and draws attention to the need for more objective studies regarding the use of this dermal matrix in burn scars of the head and neck. Conclusions: This collagen-elastin 1 mm dermal matrix should be used with caution for the surgical treatment of burn scars of the head and neck area, and its indication should be carefully weighted.

First-in-human exploratory trial assessing safety, feasibility, and efficacy of artificial protein (silk-elastin) in promoting healing in patients with meniscus injuries

Meniscal tears, especially those in avascular regions, pose a significant risk for osteoarthritis if repair fails. While meniscal repair is the preferred method for preserving knee function, it often has a high failure rate in avascular zones. This study aimed to evaluate the safety and potential efficacy of silk-elastin (SE), an artificial protein with wound-healing properties, for enhancing meniscal repair. Eight patients with meniscal tears in avascular areas underwent arthroscopic repair followed by SE application, including cases of lateral and medial tears, discoid lateral meniscus, and bucket-handle tears. No adverse events or reactions were attributed to SE. At 3 months post-surgery, clinical outcomes and repair sites were evaluated using MRI and arthroscopy. Significant improvements were observed in Lysholm and visual analog scale scores (P < 0.05), with the knee injury and osteoarthritis outcome scores showing significant improvement in the symptom subscale. MRI findings indicated one patient with grade 1 healing, three with grade 2, and four with grade 3 (unhealed). Arthroscopically, six patients demonstrated completely healed menisci, while two showed incomplete healing; none were classified as "unhealed." These findings suggest that SE is safe and may support meniscal healing in avascular zones, indicating its potential to improve repair outcomes.

A Histological and Clinical Study of MatriDerm® Use in Burn Reconstruction

Dermal substitutes are well established in the reconstructive ladder. MatriDerm® (Dr. Otto Suwelack Skin & Health Care AG, Billerbeck, Germany) is a single-layer dermal substitute composed of a bovine collagen (type I, III, and V) and elastin hydrolysate, that allows for immediate split-thickness skin grafting (SSG). The aim of this study was to histologically characterize the integration of MatriDerm® when used during burns surgery reconstruction. Eight subjects with nine burn scars and one acute burn wound underwent reconstruction with MatriDerm® and an immediate SSG. MatriDerm® integration and skin graft take were assessed with serial biopsies performed at weeks 1, 2, 3, and 4 and months 2, 3, 6, 9, and 12. Biopsies were assessed with standard special stains and immunohistochemistry, and representative slides were imaged with a transmission electron microscope. Patient satisfaction and clinical scar outcome were assessed with the Vancouver Scar Scale and a patient questionnaire. Histological analysis showed similar stages of wound healing as shown in other dermal templates but on a different timescale. There is early evidence of vascularization and an inflammatory infiltrate in the first 2 weeks. MatriDerm® is resorbed earlier than other dermal substitutes, with evidence of resorption at week 3, to be completely replaced by a neodermis at 2 months. The use of MatriDerm® in reconstruction with immediate skin grafting is supported histologically with early evidence of vascularization to support an epidermal autograft. Future histological studies may help further characterize the ideal dermal substitute.