Based on Ilizarov's law of tension-stress principle, distraction histogenesis technique has been widely applied in orthopaedic surgery for decades. Derived from this technique, cranial bone transport technique was mainly used for treating cranial deformities and calvarial defects. Recent studies reported that there are dense short vascular connections between skull marrow and meninges for immune cells trafficking, highlighting complex and tight association between skull and brain. Alzheimer's disease (AD) is a progressive neurodegenerative disease and the most common cause of dementia without effective therapy. Meningeal lymphatics have been recognized as an important mediator in neurological diseases. The augmentation of meningeal lymphatic drainage might be a promising therapeutic target for AD. Our proof-of-concept study has indicated that cranial bone transport can promote ischemic stroke recovery via modulating meningeal lymphatic drainage function, providing a rationale for treating AD using cranial bone maneuver (CBM). This study aims to investigate the effects of CBM on AD and to further explore the potential mechanisms.

Transgenic 5xFAD mice model was used in this study. After osteotomy, a bone flap was used to perform CBM without damaging the dura. Open filed test, novel object recognition test and Barn's maze test were used to evaluate neurological functions of 5xFAD mice after CBM treatment. Congo red and immunofluorescence staining were used to evaluate amyloid depositions and Aβ plaques in different brain regions. Lymphangiogenesis and the level of VEGF-C were examined after CBM treatment. OVA-A647 was intra-cisterna-magna injected to evaluate meningeal lymphatic drainage function after CBM treatment.

CBM significantly improved memory functions and reduced amyloid depositions and Aβ plaques in the hippocampus of 5xFAD mice. A significant increase of meningeal lymphatic vessels in superior sagittal sinus and transverse sinus, and the upregulation of VEGF-C in meninges were observed in 5xFAD mice treated with CBM. Moreover, CBM remarkably enhanced meningeal lymphatic drainage function in 5xFAD mice (n=5-16 mice/group for all studies).

CBM may promote meningeal lymphangiogenesis and lymphatic drainage function through VEGF-C-VEGFR3 pathway, and further reduce amyloid depositions and Aβ plaques and alleviate memory deficits in AD.

Treatment for delayed wound healing resulting from peripheral vascular diseases and diabetic foot ulcers remain a challenge. A novel surgical technique named Tibial Cortex Transverse Transport has been developed for treating peripheral ischaemia, with encouraging clinical effects. However, its underlying mechanisms remain unclear. In present study, we aimed to explore the wound healing effects after undergoing this novel technique via multiple ways.

A novel rat model of Tibial Cortex Transverse Transport was established with a designed external fixator and effects on wound healing were investigated. All rats were randomized into 3 groups, with 12 rats per group: sham group (negative control), fixator group (positive control) and Tibial Cortex Transverse Transport group. Laser speckle perfusion imaging, vessel perfusion, histology and immunohistochemistry were used to evaluate the wound healing processes.

Gross and histological examinations showed that Tibial Cortex Transverse Transport technique accelerated wound closure and enhanced the quality of the newly formed skin tissues. In Tibial Cortex Transverse Transport group, HE staining demonstrated a better epidermis and dermis recovery, while immune-histochemical staining showed that Tibial Cortex Transverse Transport technique promoted local collagen deposition. Tibial Cortex Transverse Transport technique also benefited to angiogenesis and immunomodulation. In Tibial Cortex Transverse Transport group, blood flow in the wound area was higher than that ofother groups according to laser speckle imaging with more blood vessels observed. Enhanced neovascularization was seen in the Tibial Cortex Transverse Transport group with double immune-labelling of CD31 and α-SMA. The M2 macrophages at the wound site in the Tibial Cortex Transverse Transport group was also increased.

Tibial cortex transverse transport technique accelerated wound healing through enhanced angiogenesis and immunomodulation.

Aims

Treatment for delayed wound healing resulting from peripheral vascular diseases and diabetic foot ulcers remains a challenge. A novel surgical technique named ‘tibial cortex transverse transport’ (TTT) has been developed for treating peripheral ischaemia, with encouraging clinical effects. However, its underlying mechanisms remain unclear. In the present study, we explored the potential biological mechanisms of TTT surgery using various techniques in a rat TTT animal model.

Aims

Distraction osteogenesis (DO) is a useful orthopaedic procedure employed to lengthen and reshape bones by stimulating bone formation through controlled slow stretching force. Despite its promising applications, difficulties are still encountered. Our previous study demonstrated that pulsed electromagnetic field (PEMF) treatment significantly enhances bone mineralization and neovascularization, suggesting its potential application. The current study compared a new, high slew rate (HSR) PEMF signal, with different treatment durations, with the standard Food and Drug Administration (FDA)-approved signal, to determine if HSR PEMF is a better alternative for bone formation augmentation.