An integrative biology approach to understanding keratinocyte collective migration as stimulated by bioglass.

A critical phase of wound healing is the coordinated movement of keratinocytes. To this end, bioglasses show promise in speeding healing in hard tissues and skin wounds. Studies suggest that bioglass materials may promote wound healing by inducing positive cell responses in proliferation, growth factor production, expression of angiogenic factors, and migration.

Biomimetic human skin model patterned with rete ridges.

Rete ridges consist of undulations between the epidermis and dermis that enhance the mechanical properties and biological function of human skin. However, most human skin models are fabricated with a flat interface between the epidermal and dermal layers. Here, we report a micro-stamping method for producing human skin models patterned with rete ridges of controlled geometry.

Finite Element Analysis Modelling of Negative Pressure Wound Therapy Drapes.

Negative pressure wound therapy (NPWT) drape removal from the skin may be painful for patients and inadvertently cause skin damage during the length of therapy. Most NPWT drapes utilize an acrylate adhesive to achieve the seal. To improve the experience associated with NPWT drape removal, a novel hybrid drape was developed.

Hypoxic culture and insulin yield improvements to fibrin-based engineered tissue.

We examined the effect of insulin supplementation and hypoxic culture (2% vs. 20% oxygen tension) on collagen deposition and mechanical properties of fibrin-based tubular tissue constructs seeded with neonatal human dermal fibroblasts. The results presented here demonstrate that constructs cultured under hypoxic conditions with insulin supplementation increased in collagen density by approximately five-fold and both the ultimate tensile strength (UTS) and modulus by more than three-fold compared with normoxic (20% oxygen tension), noninsulin supplemented controls.

Ruthenium-catalyzed photo cross-linking of fibrin-based engineered tissue.

Most cross-linking methods utilize chemistry or physical processes that are detrimental to cells and tissue development. Those that are not as harmful often do not provide a level of strength that ultimately meets the required application. The purpose of this work was to investigate the use of a ruthenium-sodium persulfate cross-linking system to form dityrosine in fibrin-based engineered tissue.

Implantable arterial grafts from human fibroblasts and fibrin using a multi-graft pulsed flow-stretch bioreactor with noninvasive strength monitoring.

Tissue-engineered arteries based on entrapment of human dermal fibroblasts in fibrin gel yield completely biological vascular grafts that possess circumferential alignment characteristic of native arteries and essential to their mechanical properties. A bioreactor was developed to condition six grafts in the same culture medium while being subjected to similar cyclic distension and transmural flow resulting from pulsed flow distributed among the graft lumens via a manifold. The lumenal pressure and circumferential stretch were noninvasively monitored and used to calculate stiffness in the range of 80-120 mmHg and then to successfully predict graft burst strength.

Controlled compaction with ruthenium-catalyzed photochemical cross-linking of fibrin-based engineered connective tissue.

Tissue engineering utilizing fibrin gel as a scaffold has the advantage of creating a completely biological replacement. Cells seeded in a fibrin gel can induce fibril alignment by traction forces when subjected to appropriate mechanical constraints. While gel compaction is key to successful tissue fabrication, excessive compaction can result due to low gel stiffness.

Transmural flow bioreactor for vascular tissue engineering.

Nutrient transport limitation remains a fundamental issue for in vitro culture of engineered tissues. In this study, perfusion bioreactor configurations were investigated to provide uniform delivery of oxygen to media equivalents (MEs) being developed as the basis for tissue-engineered arteries. Bioreactor configurations were developed to evaluate oxygen delivery associated with complete transmural flow (through the wall of the ME), complete axial flow (through the lumen), and a combination of these flows.