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Cellular Response to a Novel Fetal Acellular Collagen Matrix: Implications for Tissue Regeneration  [PDF]
Robert C. Rennert,Michael Sorkin,Ravi K. Garg,Michael Januszyk,Geoffrey C. Gurtner
International Journal of Biomaterials , 2013, DOI: 10.1155/2013/527957
Abstract: Introduction. PriMatrix (TEI Biosciences Inc., Boston, MA, USA) is a novel acellular collagen matrix derived from fetal bovine dermis that is designed for use in partial- and full-thickness wounds. This study analyzes the cellular response to PriMatrix in vivo, as well as the ability of this matrix to facilitate normal tissue regeneration. Methods. Five by five?mm squares of rehydrated PriMatrix were implanted in a subcutaneous fashion on the dorsum of wild-type mice. Implant site tissue was harvested for histology, immunohistochemistry (IHC), and flow cytometric analyses at multiple time points until day 28. Results. PriMatrix implants were found to go through a biological progression initiated by a transient infiltrate of inflammatory cells, followed by mesenchymal cell recruitment and vascular development. IHC analysis revealed that the majority of the implanted fetal dermal collagen fibers persisted through day 28 but underwent remodeling and cellular repopulation to form tissue with a density and morphology consistent with healthy dermis. Conclusions. PriMatrix implants undergo progressive in vivo remodeling, facilitating the regeneration of histologically normal tissue through a mild inflammatory and progenitor cell response. Regeneration of normal tissue is especially important in a wound environment, and these findings warrant further investigation of PriMatrix in this setting. 1. Introduction Extracellular matrices (ECMs) are used for a variety of surgical applications. However, differences in source species, tissues, and manufacturing processes can alter their in vivo physiomechanical properties [1–3], highlighting the importance of product choice in presurgical planning. While ideal ECM behavior varies for different clinical indications, it seems clear that products used for wound healing applications should act as a scaffold for host cellular infiltration and undergo progressive remodeling to form functional tissue without eliciting a foreign body or immunogenic response. PriMatrix is a novel acellular collagen matrix that is designed for use in partial- and full-thickness wounds. PriMatrix ECM is produced from fetal bovine dermis, a rich source of type III collagen associated with wound healing and developing tissues [1, 4, 5], and is not denatured or artificially cross-linked during the manufacturing process [1]. PriMatrix is pliable following rehydration, allowing natural alignment to the wound site, yet remains strong enough to be sutured in place. Additionally, PriMatrix is highly porous, supporting the seeding of host cells that are
Biocompatibility of acellular dermal matrix graft evaluated in culture of murine macrophages
Vendramini, Ana Paula;Melo, Rafaela Fernanda;Marcantonio, Rosemary Adriana Chiérici;Carlos, Iracilda Zepone;
Journal of Applied Oral Science , 2006, DOI: 10.1590/S1678-77572006000200001
Abstract: the acellular dermal matrix allograft has been used as an alternative to autogenous palatal mucosal graft. the aim of this study was the evaluation of the biocompatibility of an acellular dermal matrix (alloderm?) in culture of macrophages. for hydrogen peroxidase determination we used the method of pick & kesari, and the griess method for nitric oxide determination,. statistical analysis showed no significant difference (p < 0,05) in the release of nitric oxide and hydrogen peroxide by the macrophages exposed to acellular dermal matrix and the negative control. the results suggest that acellular dermal matrix did not activate the cell inflammatory response.
Macrophage phenotypes correspond with remodeling outcomes of various acellular dermal matrices  [PDF]
Hitesh Agrawal, Sunil S. Tholpady, Anthony E. Capito, David B. Drake, Adam J. Katz
Open Journal of Regenerative Medicine (OJRM) , 2012, DOI: 10.4236/ojrm.2012.13008
Abstract: Macrophages have recently been characterized as having an M1 or M2 phenotype based on receptor expression, mechanism of activation and function. The effects of macrophage phenotype upon tissue remodeling following implantation of an acellular dermal matrix (ADM) is largely unknown. The purpose of this study was to compare the macrophage phenotype and tissue remodeling elicited by four different ADMs (DermaMatrix, AlloDerm, Integra and Der mACELL). ADM samples were wrapped around the inferior epigastric vessels of a rat and were harvested on 7, 14, 21 and 42 days post implantation. Immunohistologic methods were used to identify macrophage surface markers CD68 (pan macrophage), CCR7 (M1 profile), and CD206 (M2 profile). All human derived ADMs showed a bell shaped curve for distribution of CD68+ macrophages with peaks for DermaMatrix occurring at day 14 and peak influx for AlloDerm occurring on day 21. In contrast, bovine derived Integra showed an increasing trend of macrophages with time. DermACELL had the highest influx of macro- phages while Integra had the lowest. A quantitative analysis of phenotype of macrophages in AlloDerm showed that the cells were predominantly M1 at 7, 14, 21 and 42 days post implantation. In contrast, Integra showed a mixed M1/M2 population of macrophages at all time points. The histopathologic evaluation showed that a predominantly M1 macrophage response was associated with a more inflamematory type tissue remodeling outcome in AlloDerm while a mixed M1/M2 macrophage response was associated with a more constructive tissue remodeling response seen in the other substrates.
Application of acellular dermal matrix for intestinal elongation in animal models  [cached]
Hui-Min Xu, Zhen-Jun Wang, Jia-Gang Han, Hua-Chong Ma, Bo Zhao, Bao-Cheng Zhao
World Journal of Gastroenterology , 2010,
Abstract: AIM: To investigate the efficacy of acellular dermal matrix (ADM) for intestinal elongation in animal models.METHODS: Japanese white big-ear rabbits (n = 9) and Wuzhishan miniature pigs (n = 5) were used in the study. Home-made and commercial ADM materials were used as grafts, respectively. A 3-cm long graft was interposed in continuity with the small bowel and a side-to-side anastomosis, distal to the graft about 3-4 cm, was performed. The animals were sacrificed at 2 wk, 4 wk, 8 wk and 3 mo after surgery and the histological changes were evaluated under light microscope and electron microscope.RESULTS: The animals survived after the operation with no evidence of peritonitis and sepsis. Severe adhesions were found between the graft and surrounding intestine. The grafts were completely absorbed within postoperative two or three months except one. Histological observation showed inflammation in the grafts with fibrinoid necroses, infiltration of a large amount of neutrophils and leukomonocytes, and the degree varied in different stages. The neointestine with well-formed structures was not observed in the study.CONCLUSION: It is not suitable to use acellular dermal matrix alone as a scaffold for the intestinal elongation in animal models.
Acellular dermal graft for repair of abdominal wall defects in rabbits  [cached]
A.K. Gangwar,A.K. Sharma,Naveen Kumar,N. Kumar
Journal of the South African Veterinary Association , 2012, DOI: 10.4102/jsava.v77i2.349
Abstract: Sixteen clinically healthy New Zealand white rabbits of either sex were divided into 2 equal groups (I and II) of 8 animals each. Under thiopental sodium (2.5 %) anaesthesia a 2 — 3 cm full-thickness abdominal wall defect in the mid-ventral abdominal wall was created and repaired with an acellular dermal graft (ADG) in all the animals of group I (test group). In animals of group II (control group) a full-thickness linear midline abdominal muscular wall incision was made and repaired with a continuous suture pattern using 2-0 nylon.
Long-Term Followup of Dermal Substitution with Acellular Dermal Implant in Burns and Postburn Scar Corrections  [PDF]
I. Juhasz,B. Kiss,L. Lukacs,I. Erdei,Z. Peter,E. Remenyik
Dermatology Research and Practice , 2010, DOI: 10.1155/2010/210150
Abstract: Full-thickness burn and other types of deep skin loss will result in scar formation. For at least partial replacement of the lost dermal layer, there are several options to use biotechnologically derived extracellular matrix components or tissue scaffolds of cadaver skin origin. In a survey, we have collected data on 18 pts who have previously received acellular dermal implant Alloderm. The age of these patients at the injury varied between 16 months and 84 years. The average area of the implants was 185?cm2. Among those, 15 implant sites of 14 patients were assessed at an average of 50 months after surgery. The scar function was assessed by using the modified Vancouver Scar Scale. We have found that the overall scar quality and function was significantly better over the implanted areas than over the surrounding skin. Also these areas received a better score for scar height and pliability. Our findings suggest that acellular dermal implants are especially useful tools in the treatment of full-thickness burns as well as postburn scar contractures. 1. Introduction Once the dermis of the injured skin is lost due to full-thickness burn, it will either be replaced by scar that originates from granulation tissue and epithelized from the wound edges, or skin grafting will close the wound. Neither the scar tissue, nor the patchy dermal residual islands of dermal papillae provided by the split-thickness skin graft (STSG) will result in a continuous healthy dermal layer to the wound site. The quality and function of dermal connective tissue and the amount and orientation of dermal elastic fibers have great impact on postinjury skin quality. The typical scar tissue is characterized by sparse elastic fibers and newly formed collagen bundles in random orientation. There are several methods available that are designed to improve the qualities of the dermal wound bed, while some of these methods aim to provide dermal tissue for replacement. Harvesting thicker grafts will enormously increase donor site morbidity; full-thickness skin grafting has a strict limitation of a mere few square cms. Donor site is often limited and when applying the gold standard of wound closure, autologous stsg, it has to be expanded to a ratio where disfiguring scarring is inevitable. A widely used alternative is to restore barrier function until definitive closure by applying temporary coverage, preferably with biological dressings. A large variety of methods are available ranging from xenograft (frog’s membrane to porcine skin) to allogenic tissue (e.g., placenta, frozen-, cryopreserved- or
Evaluation of in vitro human gingival fibroblast seeding on acellular dermal matrix
Rodrigues, Annelissa Zorzeto;Oliveira, Paulo Tambasco de;Novaes Jr., Arthur Belém;Maia, Luciana Prado;Souza, Sérgio Luís Scombatti de;Palioto, Daniela Bazan;
Brazilian Dental Journal , 2010, DOI: 10.1590/S0103-64402010000300001
Abstract: the acellular dermal matrix (adm) was introduced in periodontology as a substitute for the autogenous grafts, which became restricted because of the limited source of donor's tissue. the aim of this study was to investigate, in vitro, the distribution, proliferation and viability of human gingival fibroblasts seeded onto adm. adm was seeded with human gingival fibroblasts for up to 21 days. the following parameters were evaluated: cell distribution, proliferation and viability. results revealed that, at day 7, fibroblasts were adherent and spread on adm surface, and were unevenly distributed, forming a discontinuous single cell layer; at day 14, a confluent fibroblastic monolayer lining adm surface was noticed. at day 21, the cell monolayer exhibited a reduction in cell density. at 7 days, about to 90% of adherent cells on adm surface were cycling while at 14 and 21 days this proportion was significantly reduced. a high proportion of viable cell was detected on amd surface both on 14 and 21 days. the results suggest that fibroblast seeding onto adm for 14 days can allow good conditions for cell adhesion and spreading on the matrix; however, migration inside the matrix was limited.
Coverage of Megaprosthesis with Human Acellular Dermal Matrix after Ewing's Sarcoma Resection: A Case Report  [PDF]
Robert M. Whitfield,Jeremy Rinard,David King
Sarcoma , 2011, DOI: 10.1155/2011/978617
Abstract: A 23-year-old female with Ewing's Sarcoma underwent tibial resection and skeletal reconstruction using proximal tibial allograft prosthetic reconstruction with distal femur endoprosthetic reconstruction and rotating hinge. Human acellular dermal matrix, (Alloderm, LifeCell, Branchburg, NJ, USA), was used to wrap the skeletal reconstruction. Soft tissue reconstruction was completed with a rotational gastrocnemius muscle flap and skin graft. Despite prolonged immobilization, the patient quickly regained full range of motion of her skeletal reconstruction. Synthetic mesh, tapes and tubes are used to perform capsule reconstruction of megaprosthesis. This paper describes the role of human acellular dermal matrix in capsule reconstruction around a megaprosthesis.
Coverage of Megaprosthesis with Human Acellular Dermal Matrix after Ewing's Sarcoma Resection: A Case Report  [PDF]
Robert M. Whitfield,Jeremy Rinard,David King
Sarcoma , 2011, DOI: 10.1155/2011/978617
Abstract: A 23-year-old female with Ewing's Sarcoma underwent tibial resection and skeletal reconstruction using proximal tibial allograft prosthetic reconstruction with distal femur endoprosthetic reconstruction and rotating hinge. Human acellular dermal matrix, (Alloderm, LifeCell, Branchburg, NJ, USA), was used to wrap the skeletal reconstruction. Soft tissue reconstruction was completed with a rotational gastrocnemius muscle flap and skin graft. Despite prolonged immobilization, the patient quickly regained full range of motion of her skeletal reconstruction. Synthetic mesh, tapes and tubes are used to perform capsule reconstruction of megaprosthesis. This paper describes the role of human acellular dermal matrix in capsule reconstruction around a megaprosthesis. 1. Introduction Megaprosthesis reconstruction in combination with large soft tissue resection leaves complicated wounds at increased risk for infection. Patients will be immobilized in full extension following reconstruction of the extensor mechanism to minimize the risk of wound complications and optimize active knee extension following reconstruction of the knee with megaprosthesis. The trevira tube, Dacron, and other synthetic meshes have been used in the reconstruction of joint capsule and reattachment of muscles [1, 2]. These synthetic products do not completely isolate the prosthesis within the wound. Another way to perform the capsule reconstruction is to use human acellular dermal matrix, Alloderm (LifeCell, Branchburg, NJ, USA). Near-complete isolation of the megaprosthesis can be achieved with this reconstructive technique. The acellular dermis has had the cells removed through chemical and physical processing [3]. This leaves a biologic scaffold capable of cellular in-growth and revascularization [4]. This paper demonstrates the use of human acellular dermal matrix in the capsule reconstruction around a megaprosthesis. 2. Materials and Methods A 23-year-old female with Ewing’s sarcoma of left lower extremity underwent tumor resection, immediate skeletal reconstruction, knee capsule reconstruction, and soft tissue reconstruction. The resection was a wide resection of distal femur and proximal tibia with preservation of the extensor mechanism. Skeletal reconstruction was completed using proximal tibial allograft prosthetic reconstruction with distal femur endoprosthetic reconstruction and rotating hinge (Figure 1). The extensor mechanism had been reconstructed using the allograft extensor tendon oversewn to the native extensor tendon remnant. The acellular dermis was wrapped and around the
Comparative Clinical Evaluation of Subepithelial Connective Tissue Graft and Acellular Dermal Matrix Allograft for the Treatment of Gingival Recession  [PDF]
F. Haghighati,M. Mousavi,N. Moslemi
Journal of Dentistry of Tehran University of Medical Sciences , 2006,
Abstract: Statement of Problem: Various surgical procedures have been used to achieve root coverage and subepithelial connective tissue graft (SCTG) is identified as one of the most successful techniques. Recently, acellular dermal matrix allograft (ADMA) has been developed as a substitute for SCTG to avoid removing the palatal connective tissue.Purpose: The present study compared the clinical efficiency of ADMA and SCTG in the treatment of recession defects.Materials and Methods: This randomized controlled clinical study, consisted of nine patients with 32 Miller’s class I or II recession defects of ≥ 2 mm on the facial aspects of premolar teeth. Bleeding on Probing Index (BPI), Plaque Index (PI), Probing Depth (PD), Recession Depth (RD), Recession Width and Clinical Attachment Level (CAL)were measured at baseline and 6, 12 and 24 weeks post-surgery. Before operation, the samples were randomly allocated to ADMA (test) or SCTG (control) groups.Results: A statistically significant improvement was observed in RD, RW and CAL,but not in BPI, PI and PD. The mean values of changes in all clinical parameters from baseline to 24 weeks postsurgery were not significantly different between the two groups. There was no significant difference in the amount of mean root coveragebetween the ADMA (85.42%) and SCTG (69.05%) groups (P= 0.058).Conclusion: ADMA may be a useful substitute for SCTG in the treatment of shallow to moderate gingival recessions, if the financial aspect is not an issue for the patient.
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