This study evaluated the effect of pulsed low-intensity ultrasound on cell proliferation, collagen production and glycosaminoglycan deposition by human dermal fibroblasts encapsulated in alginate. Hoechst 33258 assay for cell number, hydroxyproline assay for collagen content, dimethylmethylene blue assay for glycosaminoglycan content and scanning electron microscopy were performed on the encapsulated cells treated with pulsed low-intensity ultrasound and a control group that remained untreated. Pulsed low-intensity ultrasound showed a significant effect on cell proliferation and collagen deposition but no consistent pattern for glycosaminoglycan content. Alcian blue staining showed that glycosaminoglycans were deposited around the cells in both treated and control groups. These results suggest that pulsed low-intensity ultrasound alone shows a positive effect on cell proliferation and collagen deposition even without growth factor supplements.
Human saphenous vein (hSV) and synthetic grafts are commonly used conduits in vascular grafting, despite high failure rates. Decellularising hSVs (D-hSVs) to produce vascular scaffolds might be an effective alternative. We assessed the effectiveness of a detergent-based method using 0% to 1% sodium dodecyl sulphate (SDS) to decellularise hSV. Decellularisation effectiveness was measured in vitro by nuclear counting, DNA content, residual cell viability, extracellular matrix integrity and mechanical strength. Cytotoxicity was assessed on human and porcine cells. The most effective SDS concentration was used to prepare D-hSV grafts that underwent preliminary in vivo testing using a porcine carotid artery replacement model. Effective decellularisation was achieved with 0.01% SDS, and D-hSVs were biocompatible after seeding. In vivo xeno-transplantation confirmed excellent mechanical strength and biocompatibility with recruitment of host cells without mechanical failure, and a 50% patency rate at 4-weeks. We have developed a simple biocompatible methodology to effectively decellularise hSVs. This could enhance vascular tissue engineering toward future clinical applications.
Wound represents a significant socioeconomic burden for both affected individuals and as a whole healthcare system. Accordingly, stem cells have garnered attention due to their differentiation capacity and ability to aid tissue regeneration by releasing biologically active molecules, found in the cells' cultivated medium which known as conditioned medium (CM) or secretomes. This acellular approach provides a huge advantage over conventional treatment options, which are mainly used cellular treatment at wound closure. Interestingly, the secretomes contained the cell-secreted proteins such as growth factors, cytokines, chemokines, extracellular matrix (ECM), and small molecules including metabolites, microvesicles, and exosomes. This review aims to provide a general view on secretomes and how it is proven to have great potential in accelerating wound healing. Utilizing the use of secretomes with its secreted proteins and suitable biomaterials for fabrications of acellular skin substitutes can be promising in treating skin loss and accelerate the healing process.