Advances in non-invasive biosensing measures to monitor wound healing progression

Impaired wound healing is a significant financial and medical burden. The synthesis and deposition of extracellular matrix (ECM) in a new wound is a dynamic process that is constantly changing and adapting to the biochemical and biomechanical signaling from the extracellular microenvironments of the wound. This drives either a regenerative or fibrotic and scar-forming healing outcome. Disruptions in ECM deposition, structure, and composition lead to impaired healing in diseased states, such as in diabetes. Valid measures of the principal determinants of successful ECM deposition and wound healing include lack of bacterial contamination, good tissue perfusion, and reduced mechanical injury and strain. These measures are used by wound-care providers to intervene upon the healing wound to steer healing toward a more functional phenotype with improved structural integrity and healing outcomes and to prevent adverse wound developments. In this review, we discuss bioengineering advances in 1) non-invasive detection of biologic and physiologic factors of the healing wound, 2) visualizing and modeling the ECM, and 3) computational tools that efficiently evaluate the complex data acquired from the wounds based on basic science, preclinical, translational and clinical studies, that would allow us to prognosticate healing outcomes and intervene effectively. We focus on bioelectronics and biologic interfaces of the sensors and actuators for real time biosensing and actuation of the tissues. We also discuss high-resolution, advanced imaging techniques, which go beyond traditional confocal and fluorescence microscopy to visualize microscopic details of the composition of the wound matrix, linearity of collagen, and live tracking of components within the wound microenvironment. Computational modeling of the wound matrix, including partial differential equation datasets as well as machine learning models that can serve as powerful tools for physicians to guide their decision-making process are discussed

Endogenous Interleukin-10 Contributes to Wound Healing and Regulates Tissue Repair

INTRODUCTION: Interleukin-10 (IL-10) is essential in fetal regenerative wound healing and likewise promotes a regenerative phenotype in adult dermal wounds. However, the role of endogenous IL-10 in postnatal dermal wound healing is not well-established. We sought to determine the function of endogenous IL-10 in murine full thickness excisional wounds that are splinted to prevent contracture and mimic human patterns of wound closure. METHODS: Full-thickness excisional wounds were made in wildtype (WT) and IL-10 RESULTS: We observed no difference in wound healing rate between WT and IL-10 CONCLUSIONS: These data suggest that endogenous IL-10 expression does not alter closure of full thickness excisional wounds when wound hydration and excessive contraction of murine skin are controlled. However, the loss of IL-10 leads to increased inflammatory cell infiltration and scarring. These new findings suggest that IL-10 contributes to the regulation of inflammation without compromising the healing response. These data combined with previous reports of increased rates of healing in IL-1

Injectable Antioxidant and Oxygen-Releasing Lignin Composites to Promote Wound Healing

The application of engineered biomaterials for wound healing has been pursued since the beginning of tissue engineering. Here, we attempt to apply functionalized lignin to confer antioxidation to the extracellular microenvironments of wounds and to deliver oxygen from the dissociation of calcium peroxide for enhanced vascularization and healing responses without eliciting inflammatory responses. Elemental analysis showed 17 times higher quantity of calcium in the oxygen-releasing nanoparticles. Lignin composites including the oxygen-generating nanoparticles released around 700 ppm oxygen per day at least for 7 days. By modulating the concentration of the methacrylated gelatin, we were able to maintain the injectability of lignin composite precursors and the stiffness of lignin composites suitable for wound healing after photo-cross-linking. In situ formation of lignin composites with the oxygen-releasing nanoparticles enhanced the rate of tissue granulation, the formation of blood vessels, and the infiltration of α-smooth muscle actin+ fibroblasts into the wounds over 7 days. At 28 days after surgery, the lignin composite with oxygen-generating nanoparticles remodeled the collagen architecture, resembling the basket-weave pattern of unwounded collagen with minimal scar formation. Thus, our study shows the potential of functionalized lignin for wound-healing applications requiring balanced antioxidation and controlled release of oxygen for enhanced tissue granulation, vascularization, and maturation of collagen

Advances in non-invasive biosensing measures to monitor wound healing progression

Impaired wound healing is a significant financial and medical burden. The synthesis and deposition of extracellular matrix (ECM) in a new wound is a dynamic process that is constantly changing and adapting to the biochemical and biomechanical signaling from the extracellular microenvironments of the wound. This drives either a regenerative or fibrotic and scar-forming healing outcome. Disruptions in ECM deposition, structure, and composition lead to impaired healing in diseased states, such as in diabetes. Valid measures of the principal determinants of successful ECM deposition and wound healing include lack of bacterial contamination, good tissue perfusion, and reduced mechanical injury and strain. These measures are used by wound-care providers to intervene upon the healing wound to steer healing toward a more functional phenotype with improved structural integrity and healing outcomes and to prevent adverse wound developments. In this review, we discuss bioengineering advances in 1) non-invasive detection of biologic and physiologic factors of the healing wound, 2) visualizing and modeling the ECM, and 3) computational tools that efficiently evaluate the complex data acquired from the wounds based on basic science, preclinical, translational and clinical studies, that would allow us to prognosticate healing outcomes and intervene effectively. We focus on bioelectronics and biologic interfaces of the sensors and actuators for real time biosensing and actuation of the tissues. We also discuss high-resolution, advanced imaging techniques, which go beyond traditional confocal and fluorescence microscopy to visualize microscopic details of the composition of the wound matrix, linearity of collagen, and live tracking of components within the wound microenvironment. Computational modeling of the wound matrix, including partial differential equation datasets as well as machine learning models that can serve as powerful tools for physicians to guide their decision-making process are discussed

Advances in Non-invasive Biosensing Measures to Monitor Wound Healing Progression

Impaired wound healing is a significant financial and medical burden. The synthesis and deposition of extracellular matrix (ECM) in a new wound is a dynamic process that is constantly changing and adapting to the biochemical and biomechanical signaling from the extracellular microenvironments of the wound. This drives either a regenerative or fibrotic and scar-forming healing outcome. Disruptions in ECM deposition, structure, and composition lead to impaired healing in diseased states, such as in diabetes. Valid measures of the principal determinants of successful ECM deposition include bacterial contamination, tissue perfusion, and mechanical injury and strain. These measures are used by wound-care providers to intervene upon the healing wound to steer healing toward a more functional phenotype with improved structural integrity and healing outcomes and to prevent adverse wound developments.In this review, we discuss bioengineering advances in non-invasive detection of biologic and physiologic factors of the healing wound, visualizing and modeling the ECM, and computational tools to efficiently evaluate the complex data acquired from the wounds to prognosticate healing outcomes and intervene effectively. We focus on bioelectronics and biologic interfaces of the sensors and actuators for real time biosensing and actuation. We also discuss high-resolution, advanced imaging techniques, which go beyond traditional confocal and fluorescence microscopy to visualize microscopic details of the composition of the matrix, linearity of collagen, and live tracking of components within the ECM. Computational modeling of the matrix, including partial differential equation datasets as well as machine learning models that can serve as powerful tools for physicians to guide their decision-making process are discussed.</jats:p

Endogenous IL-10 Contributes to Wound Healing and Regulates Tissue Repair

AbstractBackgroundInterleukin-10 (IL-10) is essential in fetal regenerative wound healing and likewise promotes a regenerative phenotype in adult dermal wounds. However, the role of endogenous IL-10 in postnatal dermal wound healing is not well established. We sought to determine the role of IL-10 in murine full thickness, excisional wounds that are splinted to prevent contracture and mimic human patterns of wound closure.MethodsFull thickness, excisional wounds were made in wildtype (WT) and IL-10-/- mice on a C57BL/6J background (F/M, 8wks old). In a subset of wounds, contraction was prevented by splinting with silicone stents (stenting) and maintaining a moist wound microenvironment using a semi-occlusive dressing. Wounds were examined for re-epithelialization, granulation tissue deposition, and inflammatory cell infiltrate at day 7 and fibrosis and scarring at day 30 post-wounding.ResultsWe observed no difference in wound healing rate between WT and IL-10-/- mice in either the stented or unstented group. At day 7, unstented IL-10-/- wounds had a larger granulation tissue area and more inflammatory infiltrate than their WT counterparts. However, we did observe more F4/80+ cell infiltrate in stented IL-10-/- wounds at day 7. At day 30, stented wounds had increased scar area and epithelial thickness compared to unstented wounds.ConclusionsThese data suggest that endogenous IL-10 expression does not alter closure of full thickness excisional wounds when wound hydration and excessive contraction are controlled. However, the loss of IL-10 leads to increased inflammatory cell infiltration and scarring. These data suggest that previous reports of increased rates of healing in IL-10-/- mice ought to be revisited considering recent advances in wound healing models. Moreover, these new findings suggest that IL-10 contributes to regulation of inflammation without compromising the healing response.</jats:sec

Lignin Composites with Sustained Oxygenation and Reactive Oxygen Species-Scavenging Improve Neovascularization and Healing of Diabetic Wounds

ABSTRACTAlthough delayed wound healing is an important clinical complication in diabetic patients, few targeted treatments are available, and it remains challenging to promote diabetic wound healing. Impaired neovascularization is one of the prime characteristics of the diabetic phenotype of delayed wound healing. Additionally, increased levels of reactive oxygen species (ROS) and chronic low-grade inflammation and hypoxia are associated with diabetes, which disrupts mechanisms of wound healing. We developed lignin composites with multiple wound healing-promotive functions, including pro-angiogenesis, sustained oxygenation from calcium peroxide (CaO2)-based oxygen releasing nanoparticles and ROS–scavenging with thiolated lignosulfonate that captures the elevated ROS in diabetic wounds. The sustained release of oxygen and ROS-scavenging by the lignin composites promoted endothelial cell branching and their reorganization into characteristic network formationin vitro, promoted angiogenic growth factor expression and angiogenesis in full thickness skin wounds tested in a diabetic murine model of delayed wound healing, and decreased hypoxia inducible factor-1α (HIF-1α) expression. These effects significantly increased the granulation tissue deposition and tissue repair. Our findings demonstrate that lignin composites promote diabetic wound healing without use of other drugs and show the potential of functionalized lignosulfonate for wound healing applications requiring balanced antioxidation and controlled oxygen release.</jats:p

Engineering Antioxidant and Oxygen-Releasing Lignin Composites to Promote Wound Healing

ABSTRACTThe application of engineered biomaterials for wound healing has been pursued since the beginning of tissue engineering. Here, we attempt to apply functionalized lignin to confer antioxidation to the extracellular microenvironments of wounds and to deliver oxygen from the dissociation of calcium peroxide for enhanced vascularization and healing responses without eliciting inflammatory responses. Elemental analysis showed 17 times higher quantity of calcium in the oxygen releasing nanoparticles. Lignin composites including the oxygen releasing nanoparticles released around 500 ppm oxygen per day at least for 7 days. By modulating the concentration of the methacrylated gelatin, we were able to maintain the injectability of lignin composite precursors and the stiffness of lignin composites suitable for wound healing after photo-crosslinking.In situformation of lignin composites with the oxygen releasing nanoparticles enhanced the rate of tissue granulation, the formation of blood vessels and the infiltration of α-smooth muscle actin+fibroblasts into the wounds over 7 days. At 30 days after surgery, the lignin composite with oxygen generating nanoparticles remodeled the collagen architecture resembling to the reticular pattern of unwounded collagen with minimal scar formation. Thus, our study shows the potential of functionalized lignin for wound healing applications requiring balanced antioxidation and controlled release of oxygen for enhanced tissue granulation, vascularization and maturation of collagens.</jats:p