Fabrication of nanofibrous biomaterials based on natural materials through various techniques is a popular research topic, particularly for biomedical applications. Electrospinning, a well-established technique for nanofiber production has also been extended for producing nanofibrous structures of natural materials that mimic natural extracellular matrix of mammalian tissues. Collagen nanofiber production utilizes hexafluoro propanol (HFP) as a solvent for electrospinning. A novel cost-effective electrospun nanofibrous membrane is established for wound dressing and allogeneic cultured epidermal substitute through the cultivation of human dermal keratinocytes for skin defects. Several synthetic polymers such as polycaprolactone (PCL) are generally electrospun for tissue engineering applications because of their remarkable mechanical stability and slow degradation rates. The large surface area of the polymer nanofibers with specific modifications facilitates cell adhesion and control of their cellular functions. The objectives of this study were to optimize fabrication parameters of electrospun nanofibrous membranes from biodegradable PCL and collagen-blended nanofibrous membranes to combine mechanical integrity and spinnability of PCL with high biocompatibility of collagen, and to examine keratinocyte attachment, morphology, proliferation, and cell-matrix interactions. Results prove that the porous nanofibrous PCL and modified PCL-blended collagen nanofibrous membranes are suitable for the attachment and proliferation of keratinocytes, and might have the potential to be applied as wound dressing as well as in tissue engineering as an epidermal substitute for the treatment of skin defects and burn wounds.

Sensor systems to measure pressure at the stump–socket interface of transfemoral amputees are receiving increasing attention as they allow monitoring to evaluate patient comfort and socket fit. However, transfemoral amputees have many unique characteristics, and it is unclear whether existing research on sensor systems take these sufficiently into account or if it is conducted in ways likely to lead to substantial breakthroughs. This investigation addresses these concerns through a scoping review to profile research regarding sensors in transfemoral sockets with the aim of advancing and improving prosthetic socket design, comfort and fit for transfemoral amputees. Publications found from searching four scientific databases were screened, and 17 papers were found relating to the aim of this review. After quality assessment, 12 articles were finally selected for analysis. Three main contributions are provided: a de facto methodology for experimental studies on the implications of intra-socket pressure sensor use for transfemoral amputees; the suggestion that associated sensor design breakthroughs would be more likely if pressure sensors were developed in close combination with other types of sensors and in closer cooperation with those in possession of an in-depth domain knowledge in prosthetics; and that this research would be facilitated by increased interdisciplinary cooperation and open research data generation.

Proof-of-concept computational models were developed and applied as tools to gain insights into biomechanical interactions and variations of oxygen gradients of wounded tissue subject to negative pressure wound therapy (NPWT), following trans-femoral amputation. A macro-scale finite-element model of a lower limb was first developed based on computed tomography data, and distributions of maximum and minimum principal stress values we calculated for a region of interest (ROI). Then, the obtained results were applied iteratively as new sets of boundary conditions for a specific spatial position in a capillary sub-model. Data from coupled capillary stress and mass- diffusion sub-models were transferred to the macro-scale model to map the spatial changes of tissue oxygen gradients in the ROI. The −70 mmHg NPWT resulted in a dramatic change of a wound surface area and the greatest relative contraction was observed at −150 mmHg. Tissue lateral to the depth of the wound cavity revealed homogenous patterns of decrease in oxygenation area and the extent of such decrease was dependent on the distance from the wound surface. However, tissue lateral to the width of the wound demonstrated heterogeneous patterns of change, as evidenced by both gradual increase and decrease in the oxygenation area. The multiscale models developed in the current study showed a significant influence of NPWT on both macro-deformations and changes of tissue oxygenation. The patterns of changes depended on the depth of the tissue, the geometry of the wound, and also the location of tissue plane.Electronic supplementary materialThe online version of this article (doi:10.1007/s10237-017-0921-7) contains supplementary material, which is available to authorized users.

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