Permacol (Porcine Dermal Collagen) and Alloderm (Acellular Cadaveric Dermis) as a Vascular Patch Repair for Common Carotid Arteriotomy in a Rabbit Model

Decellularized Human Dermis for Orthoplastic Extremity Reconstruction

The reconstruction of patients who possess multi morbid medical histories remains a challenge. With the ever-increasing number of patients with diabetes, infections, and trauma, there is a consistent need for promotion of soft tissue healing and a reliable substrate to assist with every aspect of soft tissue reconstruction, as well as the loss of fascial domain. Several proprietary products filled some of these needs but have failed to fulfill the needs of the clinician when faced with reconstructing multiple soft tissue systems, such as the integument and the musculoskeletal system. In this paper we discuss the use of decellularized human dermis (DermaPure®, Tissue Regenix, Universal City, TX, USA) through which a unique human tissue processing technique (dCELL® technology, Tissue Regenix, Universal City, TX, USA) and the creation of multiple product forms have proven to exhibit versatility in a wide range of clinical needs for successful soft tissue reconstruction. The background of human tissue processing, basic science, and early clinical studies are detailed, which has translated to the rationale for the success of this unique soft tissue substrate in orthoplastic reconstruction, which is also provided here in detail.

Vascular Remodeling of Clinically Used Patches and Decellularized Pericardial Matrices Recellularized with Autologous or Allogeneic Cells in a Porcine Carotid Artery Model

Background: Cardiovascular surgery is confronted by a lack of suitable materials for patch repair. Acellular animal tissues serve as an abundant source of promising biomaterials. The aim of our study was to explore the bio-integration of decellularized or recellularized pericardial matrices in vivo. Methods: Porcine (allograft) and ovine (heterograft, xenograft) pericardia were decellularized using 1% sodium dodecyl sulfate ((1) Allo-decel and (2) Xeno-decel). We used two cell types for pressure-stimulated recellularization in a bioreactor: autologous adipose tissue-derived stromal cells (ASCs) isolated from subcutaneous fat of pigs ((3) Allo-ASC and (4) Xeno-ASC) and allogeneic Wharton’s jelly mesenchymal stem cells (WJCs) ((5) Allo-WJC and (6) Xeno-WJC). These six experimental patches were implanted in porcine carotid arteries for one month. For comparison, we also implanted six types of control patches, namely, arterial or venous autografts, expanded polytetrafluoroethylene (ePTFE Propaten® Gore®), polyethylene terephthalate (PET Vascutek®), chemically stabilized bovine pericardium (XenoSure®), and detoxified porcine pericardium (BioIntegral® NoReact®). The grafts were evaluated through the use of flowmetry, angiography, and histological examination. Results: All grafts were well-integrated and patent with no signs of thrombosis, stenosis, or aneurysm. A histological analysis revealed that the arterial autograft resembled a native artery. All other control and experimental patches developed neo-adventitial inflammation (NAI) and neo-intimal hyperplasia (NIH), and the endothelial lining was present. NAI and NIH were most prominent on XenoSure® and Xeno-decel and least prominent on NoReact®. In xenografts, the degree of NIH developed in the following order: Xeno-decel > Xeno-ASC > Xeno-WJC. NAI and patch resorption increased in Allo-ASC and Xeno-ASC and decreased in Allo-WJC and Xeno-WJC. Conclusions: In our setting, pre-implant seeding with ASC or WJC had a modest impact on vascular patch remodeling. However, ASC increased the neo-adventitial inflammatory reaction and patch resorption, suggesting accelerated remodeling. WJC mitigated this response, as well as neo-intimal hyperplasia on xenografts, suggesting immunomodulatory properties.

Decellularized xenografts in regenerative medicine: From processing to clinical application

Decellularized xenografts are an inherent component of regenerative medicine. Their preserved structure, mechanical integrity and biofunctional composition have well established them in reparative medicine for a diverse range of clinical indications. Nonetheless, their performance is highly influenced by their source (ie species, age, tissue) and processing (ie decellularization, crosslinking, sterilization and preservation), which govern their final characteristics and determine their success or failure for a specific clinical target. In this review, we provide an overview of the different sources and processing methods used in decellularized xenografts fabrication and discuss their effect on the clinical performance of commercially available decellularized xenografts.

Bioengineered vascular scaffolds: the state of the art

To date, there is increasing clinical need for vascular substitutes due to accidents, malformations, and ischemic diseases. Over the years, many approaches have been developed to solve this problem, starting from autologous native vessels to artificial vascular grafts; unfortunately, none of these have provided the perfect vascular substitute. All have been burdened by various complications, including infection, thrombogenicity, calcification, foreign body reaction, lack of growth potential, late stenosis and occlusion from intimal hyperplasia, and pseudoaneurysm formation. In the last few years, vascular tissue engineering has emerged as one of the most promising approaches for producing mechanically competent vascular substitutes. Nanotechnologies have contributed their part, allowing extraordinarily biostable and biocompatible materials to be developed. Specifically, the use of electrospinning to manufacture conduits able to guarantee a stable flow of biological fluids and guide the formation of a new vessel has revolutionized the concept of the vascular substitute. The electrospinning technique allows extracellular matrix (ECM) to be mimicked with high fidelity, reproducing its porosity and complexity, and providing an environment suitable for cell growth. In the future, a better knowledge of ECM and the manufacture of new materials will allow us to "create" functional biological vessels - the base required to develop organ substitutes and eventually solve the problem of organ failure.

Hyaluronic acid biodegradable material for reconstruction of vascular wall: a preliminary study in rats

The objective of this preliminary study was to develop a reabsorbable vascular patch that did not require in vitro cell or biochemical preconditioning for vascular wall repair. Patches were composed only of hyaluronic acid (HA). Twenty male Wistar rats weighing 250-350 g were used. The abdominal aorta was exposed and isolated. A rectangular breach (1 mm × 5 mm) was made on vessel wall and arterial defect was repaired with HA made patch. Performance was assessed at 1, 2, 4, 8, and 16 weeks after surgery by histology and immunohistochemistry. Extracellular matrix components were evaluated by molecular biological methods. After 16 weeks, the biomaterial was almost completely degraded and replaced by a neoartery wall composed of endothelial cells, smooth muscle cells, collagen, and elastin fibers organized in layers. In conclusion, HA patches provide a provisional three-dimensional support to interact with cells for the control of their function, guiding the spatially and temporally multicellular processes of artery regeneration.