Biophysical Characterization of a Novel Tri-Layer Placental Allograft Membrane.

Placental tissues, including membranes composed of amnion and chorion, are promising options for the treatment of chronic wounds. Amnion and chorion contain multiple extracellular matrix (ECM) proteins and a multitude of growth factors and cytokines that, when used clinically, assist in the progression of difficult to heal wounds through restoration of a normal healing process. The objective of this study was to characterize the physical and biological properties of a dehydrated tri-layer placental allograft membrane (TPAM) consisting of a chorion layer sandwiched between two layers of amnion.

Biological characterization of dehydrated amniotic membrane allograft: Mechanisms of action and implications for wound care.

There is a growing clinical demand in the wound care market to treat chronic wounds such as diabetic foot ulcers. Advanced cell and tissue-based products (CTPs) are often used to address challenging chronic wounds where healing has stalled. These products contain active biologics such as growth factors and cytokines as well as structural components that support and stimulate cell growth and assist in tissue regeneration.

Enhanced Skin Regeneration Using a Novel Amniotic-derived Tissue Graft.

Background: Chronic and recalcitrant wounds present a significant therapeutic challenge. Amniotic tissues contain many regenerative cytokines, growth factors, and extracellular matrix molecules including proteoglycans, hyaluronic acid, and collagens I, III, and IV. Dehydrated amnion/chorion grafts are currently used to treat a variety of wounds such as diabetic foot ulcers and burns.

Enhancement of the Regenerative Potential of Anorganic Bovine Bone Graft Utilizing a Polyglutamate-Modified BMP2 Peptide with Improved Binding to Calcium-Containing Materials.

Autogenous bone is the gold standard material for bone grafting in craniofacial and orthopedic regenerative medicine. However, due to complications associated with harvesting donor bone, clinicians often use commercial graft materials that may lose their osteoinductivity due to processing. This study was aimed to functionalize one of these materials, anorganic bovine bone (ABB), with osteoinductive peptides to enhance regenerative capacity.

Microporous dermal-mimetic electrospun scaffolds pre-seeded with fibroblasts promote tissue regeneration in full-thickness skin wounds.

Electrospun scaffolds serve as promising substrates for tissue repair due to their nanofibrous architecture and amenability to tailoring of chemical composition. In this study, the regenerative potential of a microporous electrospun scaffold pre-seeded with dermal fibroblasts was evaluated. Previously we reported that a 70% collagen I and 30% poly(Ɛ-caprolactone) electrospun scaffold (70:30 col/PCL) containing 160 μm diameter pores had favorable mechanical properties, supported fibroblast infiltration and subsequent cell-mediated deposition of extracellular matrix (ECM), and promoted more rapid and effective in vivo skin regeneration when compared to scaffolds lacking micropores.

Microporous dermal-like electrospun scaffolds promote accelerated skin regeneration.

The goal of this study was to synthesize skin substitutes that blend native extracellular matrix (ECM) molecules with synthetic polymers which have favorable mechanical properties. To this end, scaffolds were electrospun from collagen I (col) and poly(ɛ-caprolactone) (PCL), and then pores were introduced mechanically to promote fibroblast infiltration, and subsequent filling of the pores with ECM. A 70:30 col/PCL ratio was determined to provide optimal support for dermal fibroblast growth, and a pore diameter, 160 μm, was identified that enabled fibroblasts to infiltrate and fill pores with native matrix molecules, including fibronectin and collagen I.

Tunable delivery of bioactive peptides from hydroxyapatite biomaterials and allograft bone using variable-length polyglutamate domains.

Hydroxyapatite (HA) biomaterials and allograft bone are common alternatives to autogenous grafts; however, these materials lack the strong osteoinductive potential of autologous bone. Previous studies have established that polyglutamate domains, which bind selectively to HA, can be engineered onto bioactive peptides as a mechanism for coupling osteoinductive signals onto HA and allograft. In the current investigation, we adapted the polyglutamate approach to tailor delivery of a model collagen-derived peptide, Asp-Gly-Glu-Ala (DGEA), by manipulating the number of glutamates in the HA binding domain.

Polyglutamate directed coupling of bioactive peptides for the delivery of osteoinductive signals on allograft bone.

Allograft bone is commonly used as an alternative to autograft, however allograft lacks many osteoinductive factors present in autologous bone due to processing. In this study, we investigated a method to reconstitute allograft with osteoregenerative factors. Specifically, an osteoinductive peptide from collagen I, DGEA, was engineered to express a heptaglutamate (E7) domain, which binds the hydroxyapatite within bone mineral.

Enhancement of peptide coupling to hydroxyapatite and implant osseointegration through collagen mimetic peptide modified with a polyglutamate domain.

Hydroxyapatite (HA) is a widely-used biomaterial for bone repair due to its high degree of osteoconductivity. However, strategies for improving HA performance by functionalizing surfaces with bioactive factors are limited. In this study, we explored the use of a HA-binding domain (heptaglutamate, "E7") to facilitate coupling of the collagen mimetic peptide, DGEA, to two types of HA-containing materials, solid HA disks and electrospun polycaprolactone matrices incorporating nanoparticulate HA.