Flexible Organic Photovoltaic-Powered Hydrogel Bioelectronic Dressing With Biomimetic Electrical Stimulation for Healing Infected Diabetic Wounds.

Electrical stimulation (ES) is proposed as a therapeutic solution for managing chronic wounds. However, its widespread clinical adoption is limited by the requirement of additional extracorporeal devices to power ES-based wound dressings. In this study, a novel sandwich-structured photovoltaic microcurrent hydrogel dressing (PMH dressing) is designed for treating diabetic wounds. This innovative dressing comprises flexible organic photovoltaic (OPV) cells, a flexible micro-electro-mechanical systems (MEMS) electrode, and a multifunctional hydrogel serving as an electrode-tissue interface. The PMH dressing is engineered to administer ES, mimicking the physiological injury current occurring naturally in wounds when exposed to light; thus, facilitating wound healing. In vitro experiments are performed to validate the PMH dressing's exceptional biocompatibility and robust antibacterial properties. In vivo experiments and proteomic analysis reveal that the proposed PMH dressing significantly accelerates the healing of infected diabetic wounds by enhancing extracellular matrix regeneration, eliminating bacteria, regulating inflammatory responses, and modulating vascular functions. Therefore, the PMH dressing is a potent, versatile, and effective solution for diabetic wound care, paving the way for advancements in wireless ES wound dressings.

[Finite element analysis of optimal selection of cannulated threaded screw for the prevention of femoral neck shortening after internal fixation for femoral neck fracture].

OBJECTIVE: To propose the an optimal screw placement scheme to prevent femoral neck shortening, finite element analysis was used to evaluate the biomechanical outcome of different numbers formed by full threaded screws at different positions in the treatment of femoral neck fractures of Pauwels type Ⅱ. METHODS: Recruited for this study was a 55-year-old female volunteer with a weight of 70 kg and a height of 165 cm. CT scan data of her right femur was collected. The models of femoral of Pauwels typeⅡ and fully threaded screw(FTS) and partially threaded screw(PTS) were constructed in three-dimensional modeling software. All these screw placement schemes were divided into eight groups simulated the inverted triangular configuration:three PTSs, an anterosuperior FTS and two PTSs, a posterosuperior FTS and two PTSs, an inferior FTS and two PTSs, an anterosuperior PTS and two FTSs, a posterosuperior PTS and two FTSs, an inferior PTS and two FTSs and three FTSs. All fracture internal fixation models were processed in finite element analysis software. Parameters of postoperative femoral neck length, displacement distribution and peak displacement of screws and VonMises stress distribution and peak stress of screws, the proximal femur and fracture section were collected. RESULTS: The maximum VonMises stress of screws was 239.71, 213.44, 199.37, 230.82, 201.63, 215.72, 185.65 and 192.64 MPa, respectively, which was concentrated in the inferior screw near the fracture line. The maximum Von Mises stress of the proximal femur was 269.48, 241.62, 249.43, 269.69, 271.60, 346.64, 236.97 and 439.62 MPa, respectively, which was concentrated in the inferior medial area of subtrochanteric femur. The maximum Von Mises stress of fracture section was 149.12, 143.04, 140.47, 139.63, 139.81, 130.07, 117.77 and 57.89 MPa, respectively, which was concentrated around the partially threaded screw channel instead of the fully threaded screw channel. The maximum displacement of screws was 5.52, 5.43, 5.32, 5.17, 5.05, 5.13, 5.28 and 5.04 mm, respectively, which was along the axis of the femoral neck, and the displacement distribution was concentrated on the tip of the screw. The length of postoperative femoral neck length was 74.69, 74.72, 74.70, 74.70, 74.72, 74.70, 74.72 and 74.74 mm, respectively. CONCLUSION: The placement of one anterosuperior partially threaded screw and two fully threaded screws with an inverted triangular distribution can not only meet the sliding compression effect to promote femoral neck healing and ensure the stability of the proximal femur, but also reduce the degree of postoperative femoral neck shortening and reduce the incidence of hip joint dysfunction. This study provides a new optimal screw placement solution for the treatment of femoral neck fractures.

lncRNA SNHG1 induced by SP1 regulates bone remodeling and angiogenesis via sponging miR-181c-5p and modulating SFRP1/Wnt signaling pathway.

BACKGROUND: We aimed to investigate the functions and underlying mechanism of lncRNA SNHG1 in bone differentiation and angiogenesis in the development of osteoporosis. METHODS: The differential gene or proteins expressions were measured by qPCR or western blot assays, respectively. The targeted relationships among molecular were confirmed through luciferase reporter, RIP and ChIP assays, respectively. Alkaline phosphatase (ALP), alizarin red S (ARS) and TRAP staining were performed to measure the osteoblast/osteoclast differentiation of BMSCs. The viability, migration and angiogenesis in BM-EPCs were validated by CCK-8, clone formation, transwell and tube formation assays, respectively. Western blot and immunofluorescence detected the cytosolic/nuclear localization of ß-catenin. Ovariectomized (OVX) mice were established to confirm the findings in vitro. RESULTS: SNHG1 was enhanced and miR-181c-5p was decreased in serum and femoral tissue from OVX mice. SNHG1 directly inhibited miR-181c-5p to activate Wnt3a/ß-catenin signaling by upregulating SFRP1. In addition, knockdown of SNHG1 promoted the osteogenic differentiation of BMSCs by increasing miR-181c-5p. In contrast, SNHG1 overexpression advanced the osteoclast differentiation of BMSCs and inhibited the angiogenesis of BM-EPCs, whereas these effects were all reversed by miR-181c-5p overexpression. In vivo experiments indicated that SNHG1 silencing alleviated osteoporosis through stimulating osteoblastogenesis and inhibiting osteoclastogenesis by modulating miR-181c-5p. Importantly, SNHG1 could be induced by SP1 in BMSCs. CONCLUSIONS: Collectively, SP1-induced SNHG1 modulated SFRP1/Wnt/ß-catenin signaling pathway via sponging miR-181c-5p, thereby inhibiting osteoblast differentiation and angiogenesis while promoting osteoclast formation. Further, SNHG1 silence might provide a potential treatment for osteoporosis.