Quality by Design: Development of Safe and Efficacious Full-Thickness Acellular Dermal Matrix Based on EuroGTPII Methodologies.

Background: The activities of tissue establishments are constantly and rapidly evolving. The development of a new type of allograft, full-thickness acellular dermal matrix, with high mechanical properties to be used in tendon repair surgeries and abdominal wall reconstruction, has determined the need for quality by design process in order to assess evidence of quality, safety and efficacy. The EuroGTPII methodologies were specifically tailored to perform the risk assessment, identify and suggest tests in order to mitigate the potential risk consequences of a novel tissue preparation implementation.

Decellularized Graft for Repairing Severe Peripheral Nerve Injuries in Sheep.

Background And Objectives: Peripheral nerve injuries resulting in a nerve defect require surgical repair. The gold standard of autograft (AG) has several limitations, and therefore, new alternatives must be developed. The main objective of this study was to assess nerve regeneration through a long gap nerve injury (50 mm) in the peroneal nerve of sheep with a decellularized nerve allograft (DCA).

Development of a full-thickness acellular dermal graft from human skin: Case report of first patient rotator cuff patch augmentation repair.

The processing and initial testing of a new human tissue preparation is described. Full-thickness Acellular Dermal Matrix (ftADM) is the extracellular matrix (ECM) obtained by decellularization of full-thickness human skin from cadaveric donors. The safety, stability and usability of the graft are discussed with respect to the results of the residual cellular content, maintenance of ECM components, and biomechanical properties.

Comparison of a human acellular dermal matrix and a polypropylene mesh for pelvic floor reconstruction: a randomized trial study in a rabbit model.

Non-absorbable polypropylene (PP) meshes have been widely used in surgical reconstruction of the pelvic floor disorders. However, they are associated with serious complications. Human acellular dermal matrices (hADM) have demonstrated safety and efficacy in reconstructive medicine, but their suitability and efficacy at vaginal level is not known.

A Comparative Study Using Fluorescent Confocal Microscopy and Flow Cytometry to Evaluate Chondrocyte Viability in Human Osteochondral Allografts.

The preservation conditions of fresh osteochondral allografts for clinical applications are critical due their objective: to transplant mature hyaline cartilage containing viable chondrocytes, maintaining their metabolic activity and also preserving the structural and functional characteristics of the extracellular matrix. The aim of the present study was to compare fluorescence confocal microscopy and flow cytometry techniques to evaluate the viability of the chondrocytes present in the osteochondral tissue, in order to determine their effectiveness and thus ensure reproducibility and robustness of the analysis. To this end, osteochondral allografts from human cadaveric donors were preserved at 4 °C for 3 weeks in a preservation medium supplemented with antibiotic and antifungal agents.

A novel decellularized nerve graft for repairing peripheral nerve long gap injury in the rat.

Decellularized nerve allografts are an alternative to autograft for repairing severe nerve injuries, since they have higher availability and do not induce rejection. In this study, we have assessed the regenerative potential of a novel decellularization protocol for human and rat nerves for repairing nerve resections, compared to the gold standard autograft. A 15-mm gap in the sciatic nerve was repaired with decellularized rat allograft (DC-RA), decellularized human xenograft (DC-HX), or fresh autograft (AG).

"Off-the-Shelf" Nerve Matrix Preservation.

Decellularized human nerves overcome the limitations of the current treatments for large peripheral nerve injuries. However, the use of decellularized nerves requires an "off-the-shelf" availability for useful and actual clinical application. In this study, we addressed the preservation of the native and decellularized human nerve matrix in an integrative approach for tissue scaffold production.

Fast protocol for the processing of split-thickness skin into decellularized human dermal matrix.

Background: Dermal scaffolds for tissue regeneration are nowadays an effective alternative in not only wound healing surgeries but also breast reconstruction, abdominal wall reconstruction and tendon reinforcement. The present study describes the development of a decellularization protocol applied to human split-thickness skin from cadaveric donors to obtain dermal matrix using an easy and quick procedure.

Methods: Complete split-thickness donor was decellularized through the combination of hypertonic and enzymatic methods.

Rabbit as an animal model for the study of biological grafts in pelvic floor dysfunctions.

The aims of this study were to evaluate the feasibility of the New Zealand White (NZW) rabbit for studying implanted biomaterials in pelvic reconstructive surgery; and to compare the occurrence of graft-related complications of a commercial polypropylene (PP) mesh and new developed human dermal matrix implanted at vaginal and abdominal level. 20 white female NZW rabbits were randomized into two groups, experimental group (human acellular dermal matrices-hADM-graft) and control group (commercial PP graft). In each animal, grafts were surgically implanted subcutaneously in the abdominal wall and in the vaginal submucosa layer for 180 days.

Effective decellularization of human nerve matrix for regenerative medicine with a novel protocol.

Injuries to the peripheral nerves represent a frequent cause of permanent disability in adults. The repair of large nerve lesions involves the use of autografts, but they have several inherent limitations. Overcoming these limitations, the use of decellularized nerve matrix has emerged as a promising treatment in tissue regenerative medicine.

Which type of bone releases the most vancomycin? Comparison of spongious bone, cortical powder and cortico-spongious bone.

Bone infections can be challenging to treat and can lead to several surgeries and relapses. When a graft is needed, cavitary bone loss can be grafted with cancellous or cortical bone. Both can be used for grafting.

In Vitro Antimicrobial Photodynamic Therapy Against Trichophyton mentagrophytes Using New Methylene Blue as the Photosensitizer.

Introduction And Objectives: Antimicrobial photodynamic therapy combines the use of a photosensitizing drug with light and oxygen to eradicate pathogens. Trichophyton mentagrophytes is a dermatophytic fungus able to invade the skin and keratinized tissues. We have investigated the use of new methylene blue as the photosensitizing agent for antimicrobial photodynamic therapy to produce the in vitro inactivation of T mentagrophytes.

Effective and durable genetic modification of human mesenchymal stem cells via controlled release of rAAV vectors from self-assembling peptide hydrogels with a maintained differentiation potency.

Controlling the release of recombinant adeno-associated virus (rAAV) vectors from biocompatible materials is a novel, attractive approach to increase the residence time and effectiveness of a gene carrier at a defined target site. Self-assembling peptides have an ability to form stable hydrogels and encapsulate cells upon exposure to physiological pH and ionic strength. Here, we examined the capacity of the peptide hydrogel RAD16-I in a pure (RAD) form or combined with hyaluronic acid (RAD-HA) to release rAAV vectors as a means to genetically modify primary human bone marrow-derived mesenchymal stem cells (hMSCs), a potent source of cells for regenerative medicine.

Bimolecular based heparin and self-assembling hydrogel for tissue engineering applications.

One major goal of tissue engineering is to develop new biomaterials that are similar structurally and functionally to the extracellular matrix (ECM) to mimic natural cell environments. Recently, different types of biomaterials have been developed for tissue engineering applications. Among them, self-assembling peptides are attractive candidates to create artificial cellular niches, because their nanoscale network and biomechanical properties are similar to those of the natural ECM.

Multivalent dendrimers presenting spatially controlled clusters of binding epitopes in thermoresponsive hyaluronan hydrogels.

The controlled presentation of biofunctionality is of key importance for hydrogel applications in cell-based regenerative medicine. Here, a versatile approach was demonstrated to present clustered binding epitopes in an injectable, thermoresponsive hydrogel. Well-defined multivalent dendrimers bearing four integrin binding sequences and an azido moiety were covalently grafted to propargylamine-derived hyaluronic acid (Hyal-pa) using copper-catalyzed alkyne-azide cycloaddition (CuAAC), and then combined with pN-modified hyaluronan (Hyal-pN).

On the mechanism of Candida spp. photoinactivation by hypericin.

The photoprocesses involved in hypericin photoinactivation of three different Candida species (C. albicans, C. parapsilosis and C.