Development of a Facile Lysosome-Targeting Nitric Oxide Fluorescent Probe Based on a Novel Reaction Mechanism.

As a ubiquitous signal molecule in biosystems, nitric oxide (NO) plays an important role in many physiological and pathological processes. Therefore, it is of great significance to detect NO in organisms for the study of related diseases. Currently, a variety of NO fluorescent probes have been developed based on several types of reaction mechanisms. However, due to the inherent disadvantages of these reactions, like potential interference by biologically related species, there is a great need to develop NO probes based on the new reactions. Herein, we report our discovery of the unprecedented reaction between a widely used fluorophore of 4-(dicyanomethylene)-2-methyl-6-(p-(dimethylamino)styryl)-4H-pyran (DCM) and NO under mild conditions with fluorescence changes. By the analysis of the structure of the product, we proved that DCM undergoes a particular nitration process and proposed a mechanism for fluorescence changes due to the interruption of the intramolecular charge transfer (ICT) process of DCM by the nitrated product of DCM-NO2. Based on the understanding of this specific reaction, we then easily constructed our lysosomal-localized NO fluorescent probe LysoNO-DCM by linking DCM and a morpholine group, a lysosomal-targeting functional group. LysoNO-DCM exhibits excellent selectivity, sensitivity, pH stability, and outstanding lysosome localization ability with Pearson's colocalization coefficient of up to 0.92 and is successfully applied to the imaging of exogenous and endogenous NO in cells and zebrafish. Our studies expand design methods for NO fluorescence probes based on the novel reaction mechanism and will benefit the studies of this signaling molecule.

Comparing two surgical approaches for treating multilevel cervical spondylotic myelopathy: A meta-analysis.

PURPOSE: This meta-analysis aims to evaluate the therapeutic efficacy of anterior versus posterior surgical approaches for multisegment cervical spondylotic myelopathy (MCSM). METHODS: Eligible studies published between the period of January 2001 and April 2022 and comparing the anterior and posterior surgical approaches for treating cervical spondylotic myelopathy were retrieved from the PubMed, Web of Science, Embase, and Cochrane databases. RESULTS: A total of 17 articles were selected based on the inclusion and exclusion criteria. This meta-analysis failed to show any significant difference in the duration of surgery, the hospitalization time, or the improvement in the Japanese Orthopedic Association score between the anterior and posterior approaches. The anterior approach, however, exhibited increased efficacy in the improvement of the neck disability index, reduction in the visual analog scale for cervical pain, and improvement in the cervical curvature compared with the posterior approach. CONCLUSION: Bleeding was also less with the anterior surgical approach. The posterior approach provided a significantly higher range of motion of the cervical spine and showed fewer postoperative complications compared with the anterior approach. While both the surgical approaches have good clinical outcomes and show postoperative neurological function improvement, the meta-analysis shows that both anterior and posterior approaches have certain merits and shortcomings. A meta-analysis of a larger number of randomized controlled trials with longer follow-up can conclusively determine which of the surgical approaches is more beneficial in the treatment of MCSM.

Adiponectin protects skeletal muscle from ischaemia-reperfusion injury in mice through miR-21/PI3K/Akt signalling pathway.

Previous studies have confirmed that adiponectin (APN) plays a protective role in myocardial ischaemia-reperfusion (IR) injury, and the aim of this study was to investigate its effect on skeletal muscle. ELISA was used to detect the levels of Creatinine Kinase (CK), LDH, SOD and MDA in the plasma of the lower limbs of mice, and the levels of IL-6, IL-1ß and TNF-α in the gastrocnemius. Quantitative PCR was used to detect the expression level of miR-21. TUNEL staining was used to detect the apoptosis of the gastrocnemius. The expression levels of apoptosis proteins, autophagy marker proteins and downstream target genes of miR-21 in gastrocnemius were detected by Western Blot. The results of this study revealed that APN levels were significantly reduced in gastrocnemius of IR mice. The oxidative stress, inflammatory response, apoptosis and autophagy induced by IR were significantly ameliorated by APN injection. The above effects of APN may be achieved through miR-21/PI3K signalling pathway, as found by interfering gene expression levels with miRNA antagomir and lentiviral injection. Taken together, our study revealed that APN protects skeletal muscle from IR injury through miR-21 /PI3K/Akt signalling pathway through inhibiting inflammatory response, apoptosis and autophagy.

Dynamically monitoring lymphatic and vascular systems in physiological and pathological conditions of a swine model via a portable NIR-II imaging system with ICG.

Objective: NIR-II imaging with indocyanine green (ICG) has been clinically used in liver tumor resection. However, few data are available concerning the application of ICG-NIR-II in lymphatic and vascular systems in clinic. To expand the application and promote the clinical translation of this approach, we aimed to investigate the feasibility of ICG-NIR-II imaging for monitoring both lymphatic and vascular systems in physiological and pathological conditions using a swine model and compared it to ICG-NIR-I imaging. Methods: we constructed a portable NIR-II imaging system suitable for large animals. Different simulated clinical scenarios in lymphatic and vascular systems of pigs, including lymphatic drainage, lymphorrhea, lymphatic obstruction, lymphatic reconstruction in flaps, venous thrombus formation and vascular anastomosis were modeled to evaluate the reliability of our NIR-II imaging system and the imaging quality of ICG in the NIR-I/II window. Results: Under different simulated clinical scenarios, our portable NIR-II imaging system showed good reliability for pigs. With the help of the portable imaging system, dynamical visualization of lymph vessels, lymph nodes and blood vessels of pigs in different clinical scenarios could be achieved in NIR-II imaging by using the tail fluorescence of ICG. Moreover, ICG-NIR-II imaging has lower background fluorescence and higher resolution than ICG-NIR-I imaging. Conclusions: We demonstrated the first application of a portable NIR-II imaging system for dynamically monitoring both lymphatic and vascular systems in physiological and pathological conditions using a swine model. Our study indicates that ICG-NIR-II imaging be a promising approach for the diagnosis of malfunctions in lymphatic and vascular systems and the surgical navigation of microsurgery and reconstructive surgery.

Limb-Salvage Outcomes of Arterial Repair Beyond Time Limit at Different Lower-Extremity Injury Sites.

BACKGROUND The purpose of this study was to analyze the outcomes of revascularization exceeding 12 h after arterial injury at different sites of the lower extremity. MATERIAL AND METHODS From January 2009 to April 2017, 58 patients with 58 lower-limb arterial injuries who underwent revascularization over 12 h after trauma were included in our study. Outcomes measured, including mortality, amputation, complications, and other parameters (gait, length discrepancy, the range of movement of the knee and ankle joint, and muscle wasting) were analyzed. RESULTS External iliac artery injury (EIAI) or femoral artery injury (FAI) was affected in 4 patients, superficial femoral artery injury (SFAI) in 18, and popliteal artery injury (PAI) (including proximal gastrocnemius muscle vascular (PGMV) and proximal gastrocnemius muscle vascular [PGMV]) in 36. The median time of arterial injury was 72 h (interquartile range, 59.5). No mortality was found. Amputations were performed in 16 patients due to non-viable limbs, progressing infection, or muscle necrosis. All patients were followed up (median, 52 months; interquartile range, 5.5). Of the 42 limb-salvage patients, most had a limp, muscle wasting, or ankle and knee dysfunctions, and 26 patients with knee or ankle dysfunction underwent secondary surgery. CONCLUSIONS Although limited recanalization of blood vessels may lead to limb complications or amputations over time, the high success rate of limb salvage still merits the surgeon's best efforts.

The experiences of nurses infected with COVID-19 in Wuhan, China: A qualitative study.

AIM: To understand about the experiences and feelings of the nurses infected with COVID-19 when caring for patients with COVID-19. BACKGROUND: With the sudden outbreak of coronavirus disease 2019 (COVID-19), nurses take care of patients with COVID-19 and have a very high risk of being infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) themselves. METHODS: This study adopted a qualitative design of hermeneutic phenomenology. A purposeful sampling was used, and all data were collected through in-depth semi-structured telephone interviews then analysed using interpretative phenomenological analysis. RESULTS: The interview data generated 4 topics and 14 secondary topics. Four major themes were identified from this study, including 'experiences of infection', 'health belief', 'social support' and 'the pursuit of self-worth'. CONCLUSIONS: Nurses infected by COVID-19 experienced a physical and psychological shock. They had a strong sense of responsibility and willingness to take risks. Providing professional psychological counselling and physical rehabilitation services are crucial. IMPLICATIONS FOR NURSING MANAGEMENT: This manuscript provides nursing managers an understanding of the personal experiences and needs of clinical nurses in their work, especially during COVID-19. It is helpful for nursing managers to explore the greater driving force of nurses and prepare nursing human resources for greater challenges.

Repair of Massive Bone Defects of the Proximal Femur Using Iliac Bone Flaps of the Ascending Branch of the Lateral Circumflex Femoral Artery: A Retrospective Report.

BACKGROUND AND OBJECTIVE: The management of bone defects is still a difficult problem. Local vascularized bone grafts represent an efficient and widely used method. In this retrospective report, iliac bone flaps of the ascending branch of the lateral circumflex femoral artery were used for the management of proximal femur bone defects. PATIENTS AND METHODS: The hospital information system and clinical data collected by surgeons were retrospectively reviewed. Patients with massive bone defects of the proximal femur reconstructed with iliac bone flaps of the ascending branch of the lateral circumflex femoral artery were included. Relevant data, including general information, perioperative treatment, and imaging data during follow-up, were retrieved for analysis. Five patients (4 males and 1 female) aged 18 to 42 years were included in this report. All patients were diagnosed with proximal femoral bone defects. The sizes of the bone defects ranged from 5 ×4 cm to 8 × 5 cm. Harris hip score was adopted to evaluate the functional outcomes. The adverse events were recorded. The mean follow-up time was 6.3 years. RESULTS: Iliac bone flaps of the ascending branch of the lateral circumflex femoral artery were transferred locally for the 5 patients. Bone flaps were fixed with plates in 4 cases and Kirschner wires in 1 case. The hospital stay was 12 to 27 days, with an average of 19.4 days. All cases achieved bony healing after 3 to 6 months postoperatively. The Harris hip scores ranged from 87 to 95 at final follow-up. All patients achieved good to excellent functional outcomes. One superficial infection occurred. No other adverse events or serious adverse events were noted. CONCLUSIONS: Local transfer of iliac bone flaps of the ascending branch of the lateral circumflex femoral artery represents a safe and effective method for the reconstruction of massive bone defects of the proximal femur.

The Effect and Mechanism of Negative Pressure Wound Therapy on Lymphatic Leakage in Rabbits.

BACKGROUND: Lymphatic leakage is one of the severe complications after lymphadenectomy. However, efficient treatment it still unclear. MATERIALS AND METHODS: We employed inguinal lymphadenectomy and saphenous lymphatic vessel excision to establish a inguinal lymphatic leakage rabbit model. Rabbits with bilateral lymphatic leakage were divided in two groups, which were subject to negative pressure wound therapy (NPWT) on right sides and dressing change on left sides, respectively. Following 7-11 d of treatment, skin thickness and drainage volume were measured. Western blot and RT-PCR were used for analyzing the VEGF-C level. Tissues of wound were dissected and subject to anti-LYVE-1 immunohistochemical for lymphatic average positive staining area percentage and the ratio of lymphatic lumen area evaluation. RESULTS: Our lymphatic leakage model showed significant lymph stasis, delayed wound healing, and skin swelling and was confirmed by methylene blue instillation. Using this rabbit model, we found that NPWT could largely promote wound healing and resolution of skin edema. Compared with the dressing change group, the thickness of the dermis layer in the NPWT group was significantly reduced. Western blot and RT-PCR analysis showed a decrease of VEGF-C in the NPWT group. The immunohistochemical result of the NPWT group did not show a significant change in lymphatic average positive staining area percentage, whereas the ratio of lymphatic lumen area was significantly decreased, suggesting that NPWT treatment can significantly compress the dilated lymphatic vessels. CONCLUSIONS: We successfully established the first clinically relevant lymphatic leakage model in rabbits. NPWT can be an effective treatment for lymphatic leakage via reducing edema and lymphatic stasis by compressing dilated lymph vessels and promoting lymphatic drainage.

Outcomes of Vacuum Sealing Drainage Treatment Combined with Skin Flap Transplantation and Antibiotic Bone Cement on Chronic Tibia Osteomyelitis: A Case Series Study.

BACKGROUND Chronic osteomyelitis is one of the currently refractory diseases. The aim of this study is to discuss the method and curative effects of vacuum sealing drainage (VSD) treatment combined with skin flap transplantation and antibiotic bone cement for chronic tibia osteomyelitis. MATERIAL AND METHODS For this study, 18 cases of open fracture secondary chronic tibia osteomyelitis were selected. After the granulation tissue of the wound surface became fresh and infection was controlled, the wound surface was repaired with a medial head of gastrocnemius transfer flap or a myofascial and cutaneous island pedicle flap with a collateral vessel nourished by the retrograde sural nerve. VSD combined with focus debridement and antibiotic bone cement filling was conducted. After inflammation was completely regulated, elective bone cement extraction, bone grafting, and internal fixation were performed. Within 2 to 3 years of follow-up post-surgery, the satisfaction and recurrence rates were evaluated. The patients' pre-operative and post-operative recovery of limb functions were compared according to the Enneking scoring system. RESULTS The patients did not suffer from osteomyelitis recurrence, with the exception of 1 case that manifested osteomyelitis recurrence and recovered through surgical treatment within the period of follow-up. The satisfaction and recurrence rates of these study cases post-surgery were 94.4% and 5.6%, respectively. The average functional recovery post-surgery was 81.5% of normal function. CONCLUSIONS Vacuum sealing drainage combined with skin flap transplantation and antibiotic bone cement is an effective treatment for chronic tibia osteomyelitis.

Circulating fibrocyte mobilization in negative pressure wound therapy.

Non-healing diabetic wounds are difficult to treat. They also create heavy financial burdens for both patients and society. Negative pressure wound therapy (NPWT) has been adopted to treat intractable wounds and has proved to be effective. However, the mechanisms that underlie the effects of this treatment are not entirely understood. Circulating fibrocytes are unique haematopoietic-derived stem cells that have been reported to play a pivotal role in wound healing. Here, we have investigated the effect of NPWT on fibrocyte mobilization and the role of fibrocyte mobilization in the healing of diabetic wounds during NPWT. We show that the NPWT group exhibited 2.6-fold to 12.1-fold greater numbers of tail vein-injected PKH-26-labelled fibrocytes in the diabetic wound sites compared with the control group. We also demonstrate that the full-thickness skin wounds treated with NPWT exhibit significantly reduced mRNA and protein expression, blood vessel density and proliferating cells when exogenous fibrocyte mobilization is inhibited. We speculate that systemic mobilization of fibrocytes during NPWT may be a mechanism for healing intractable wounds in a diabetic rat model experiment and that enhancement of cell mobilization may represent a potential treatment idea for intractable wound healing across all fields of surgery.

Flow-Through Free Fibula Osteocutaneous Flap in Reconstruction of Tibial Bone, Soft Tissue, and Main Artery Segmental Defects.

OBJECTIVE: The aim of this report was to present the use of flow-through free fibula osteocutaneous flap for the repair of complex tibial bone, soft tissue, and main artery segmental defects. PATIENTS AND METHODS: Five patients with bone, soft tissue, and segmental anterior tibial artery defects were included. The lengths of injured tibial bones ranged from 4 to 7 cm. The sizes of impaired soft tissues were between 9 × 4 and 15 × 6 cm. The lengths of defect of anterior tibial artery segments ranged from 6 to 10 cm. Two patients had distal limb perfusion problems. Flow-through free fibula osteocutaneous flap was performed for all 5 patients. RESULTS: Patients were followed for 12 to 18 months. All wounds healed after 1-stage operation, and all flow-through flaps survived. The distal perfusion after vascular repair was normal in all patients. Superficial necrosis of flap edge was noted in 1 case. After the local debridement and partial thickness skin graft, the flap healed uneventfully, and the surgical operation did not increase injury to the donor site. Satisfactory bone union was achieved in all patients in 2 to 4 months postoperation. Enlargement of fibula graft was observed during follow-up from 12 to 18 months. The functions of adjacent joints were recovered, and all patients were able to walk normally. CONCLUSIONS: Flow-through free fibula osteocutaneous flap was shown to be an effective and efficient technique for repairing composite tibial bone, soft tissue, and main artery segmental defects. This 1-stage operation should be useful in clinical practice for the treatment of complex bone, soft tissue, and vessel defects.

Papineau technique combined with vacuum-assisted closure for open tibial fractures: clinical outcomes at five years.

PURPOSE: Treatment of open tibial fractures with soft tissue and segmental bone defects is difficult. This study reports our results for treating these injuries with a combination of Papineau open bone grafting and vacuum-assisted wound closure (VAC). METHODS: The records of 19 patients with open tibial fractures with soft tissue and segmental bone defects treated with bone grafting and VAC from 2004 to 2010 were retrospectively reviewed. Outcomes included: time to complete granulation tissue coverage, wound healing, and bone union; length of hospitalization; frequency of debridement; number of deep tissue infections. RESULTS: Initial surgery was performed within 48 hours of injury. Ten fractures were Orthopaedic Trauma Association classification 41-A3, one was 41-C3, seven were 43-A3, and one was 43-C3. No surgical complications occurred, and the mean length of hospitalization was 11.0 ± 3.0 weeks (range, 7-18 weeks). The mean follow-up time was 59.35 ± 8.76 months. The mean time for complete wound healing was 7.76 ± 1.52 weeks (range, 6-11 weeks). Bone union was achieved in all patients at a mean of 33.88 ± 8.37 weeks (range, 23-53 weeks). Only one patient developed a deep tissue infection, which was treated with antibiotics and debridements, and complete bone union wound healing was achieved. Based on Paley grade, five outcomes were excellent, eight were good, and four were fair. CONCLUSIONS: The combination of VAC and open bone grafting results in good outcome for patients with open tibial fractures and severe bone and soft-tissue defects.

Monitoring angiogenesis in skin autografts using photoacoustic microscopy.

BACKGROUND: Skin autografts have been broadly used to manage the skin and soft tissue defects. It is important for surgeons to assess the vitality of skin autografts via observing the angiogenesis. However, there is lack of reliable approach for giving the quantitative angiogenesis information on the skin autografts. Recently, photoacoustic microscopy imaging has attracted much attention based on its good performance in angiography. METHODS: In this study, we aim to monitor angiogenesis in skin autografts via PAM, and further verify its clinical potential for the early prediction of skin autografts clinical outcome. RESULTS AND CONCLUSIONS: The results indicate that PAM is a feasible, precise, high-resolution, noninvasive technique for the early prediction of necrosis of skin autografts via monitoring the angiogenesis, providing a promising tool for surgeons to use this surgical technology.

Association between circulating cell-free mitochondrial DNA and inflammation factors in noninfectious diseases: A systematic review.

OBJECTIVE: This study aimed to assess the correlation between the circulating cell-free mitochondria DNA and inflammation factors in noninfectious disease by meta-analysis of data from eligible studies. MATERIALS AND METHODS: Through a comprehensive searching of pubmed, embase, web of science, cochrane from establishment of the database to October 31, 2022, studies were selected that investigated the association of circulating cell free mitochondria DNA with inflammatory factors in non-infectious diseases. Studies that met the inclusion criteria and were published in English or Chinese were included. Data of each correlation coefficients were extracted from the paper and 95% confidence intervals were calculated. Sensitivity and heterogeneity tests were carried out for each data. RESULTS: A total of 660 articles were retrieved and 22 were included in this meta-analysis, including 2600 patients. A fixed effects model was employed to examine ISS and IL-8, others were analyzed using random effects models. The correlation coefficient between mtDNA and ISS score was 0.37 (95%CI = [0.232;0.494]), p<0.0001, heterogeneity I2 = 46%, p = 0.11). The correlation coefficients between mtDNA and inflammatory factors are as follows: TNFα, 0.405 [(95%CI = [0.253;0.538], p<0.0001, heterogeneity I2 = 77%, p = 0.0001]. IL-6, 0.469 [(95%CI = [0.296;0.612]), p = 0.0001, heterogeneity I2 = 93%, p<0.0001]. CRP, 0.333[(95%CI = [0.149;0.494]), p = 0.005, heterogeneity I2 = 85%, p<0.0001]. IL-8, 0.343[(95%CI = [0.233;0.524]), p = 0.001, heterogeneity I2 = 50%, p = 0.09]. PCT, 0.333 [(95%CI = [0.06;0.64]), p = 0.09,heterogeneity I2 = 64%,p = 0.06]. There were no significant publication bias for TNFα, IL-6 and CRP. CONSLUSION: Circulating cell free mtDNA was moderate positively correlated with the expression of inflammatory factors and the degree of trauma.

Drug-Free "Triboelectric Immunotherapy" Activating Immunity for Osteomyelitis Treatment and Recurrence Prevention.

Treatment of osteomyelitis is clinically challenging with low therapeutic efficacy and high risk of recurrence owing to the immunosuppressive microenvironment. Existing therapies are limited by drug concentration and single regulatory effect on the immune network, and emphasize the role of anti-inflammatory effects in reducing osteoclast rather than the role of proinflammatory effects in accelerating infection clearance, which is not conducive to complete bacteria elimination and recurrence prevention. Herein, a direct-current triboelectric nanogenerator (DC-TENG) is established to perform antibacterial effects and modulate immunological properties of infectious microenvironments of osteomyelitis through electrical stimulation, namely triboelectric immunotherapy. Seeing from the results, the triboelectric immunotherapy successfully activates polarization to proinflammatory (M1) macrophages in vitro, accompanied by satisfying direct antibacterial effects. The antibacterial and osteogenic abilities of triboelectric immunotherapy are verified in rat cranial osteomyelitis models. The effects on the polarization and differentiation of immune-related cells in vivo are investigated by establishing in situ tibial osteomyelitis models and immunosurveillance models in C57 mice respectively, indicating the ability of activating immunity and producing immunological memory for in situ infection and secondary recurrence, thus accelerating healing and preventing relapse. This study provides an efficient, long-acting, multifunctional, and wearable triboelectric immunotherapy strategy for drug-free osteomyelitis treatment systems.

Vacuum assisted closure therapy for treatment of complex wounds in replanted extremities.

The object of this study was to compare the outcomes of the vacuum assisted closure (VAC) therapy and conventional wound care with dressing change for treatment of complex wounds in patients with replantation of amputated upper and lower extremities. Data of 43 patients with replantation of amputated extremities from May 2004 to December 2011 were reviewed. There were 18 wounds of 18 patients with replantation, which were treated by dressing change and 26 wounds of 25 patients by VAC therapy. The outcomes were evaluated by the survival rate of replanted extremities, growth of granulation tissue, interval between wound treatment and secondary procedure and eventual secondary wound coverage methods. Vascular thromboses were found in 3 patients with wound treatment by dressing change and 5 by VAC. All replants of two groups of patients survived after salvage procedures. The wound score was 3.6 ± 0.7 in the conventional dressing change group and 5.8 ± 0.7 in the VAC group at the sixth day after treatment, respectively. The intervals between wound treatment and secondary wound coverage procedure were 12.0 ± 1.7 days in the dressing change group and 6.1 ± 0.7 days in the VAC group. Flaps were applied for wound coverage in 9 out of 18 (50.0%) wounds in the dressing change group and 5 out of 26 (19.2%) in the VAC group (P < 0.05), when the wounds of rest of patients were covered by the skin graft. The results showed that VAC could promote the growth of granulation tissue of wound, decrease the need of flap for wound coverage, and did not change the survival of replantation.

Role of different negative pressure values in the process of infected wounds treated by vacuum-assisted closure: an experimental study.

Vacuum-assisted closure (VAC) device is widely used to treat infected wounds in clinical work. Although the effect of VAC with different negative pressure values is well established, whether different negative pressures could result in varying modulation of wound relative cytokines was not clear. We hypothesise that instead of the highest negative pressure value the suitable value for VAC is the one which is the most effective on regulating wound relative cytokines. Infected wounds created on pigs' back were used to investigate the effects of varying negative pressure values of VAC devices. Wounds were treated with VAC of different negative pressure values or moist gauze, which was set as control. The VAC foam, semiocclusive dresses and moist gauze were changed on days 3, 5, 7 and 9 after wounds were created. When changing dressings, tissues from wounds were harvested for bacteria count and histology examination including Masson's trichrome stain and immunohistochemistry for microvessels. Western blot was carried out to test the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Results showed that on days 3 and 5 the number of bacteria in wounds treated by VAC with 75, 150, 225 and 300 mmHg was significantly decreased compared with that in wounds treated by gauze and 0 mmHg pressure value. However, there was no difference in wounds treated with negative pressure values of 75 , 150, 225 and 300 mmHg at any time spot. Immunohistochemistry showed that more microvessels were generated in wounds treated by VAC using 75 and 150 mmHg negative pressure comparing with that using 225 and 300 mmHg on days 3 and 5. However this difference vanished on days 7 and 9. Morphological evaluation by Masson's trichrome staining showed increased collagen deposition in VAC of 75 and 150 mmHg compared with that in VAC of 225 and 300 mmHg. Western blot showed that the expression of VEGF and bFGF significantly increased when the wounds treated with 75 and 150 mmHg negative pressure values compared with the wounds treated with 225 and 300 mmHg on day 5. Treatment using VAC with different negative pressure values more than 75 mmHg has similar efficiency on reducing bacteria in the infected wound. VAC with negative pressure values of 75 and 150 mmHg promote wound healing more quickly than other pressure values. Moreover, comparing with vigorous negative pressure, relatively moderate pressures contribute to wound healing via accelerated granulation growth, increased angiogenic factor production and improved collagen fibre deposition. Further study of this model may show other molecular mechanisms.

Role of Autologous Fat Transplantation Combined with Negative-Pressure Wound Therapy in Treating Rat Diabetic Wounds.

BACKGROUND: Negative-pressure wound therapy (NPWT) and autologous fat transplantation (AFT) are two clinical modalities for plastic and reconstructive surgery. At present, there are few reports on the combination of these two methods in treating diabetic wounds. This study aimed to explore the effect of this combined therapy on diabetic wound healing. METHODS: Full-thickness dorsal cutaneous wounds in rats with streptozotocin-induced diabetes were treated with either NPWT, AFT, or combined therapy. Rats covered with commercial dressings served as the control group. Macroscopic healing kinetics were examined. The levels of inflammation-related factors, such as interleukin-1ß (IL-1ß), interleukin-6 (IL-6), monocyte chemoattractant protein-1, arginase-1, and inducible nitric oxide synthase (iNOS) and angiogenesis-related factors such as vascular endothelial growth factor, were measured in the wound tissues on days 3, 7, and 14; immunohistochemical staining for arginase-1, iNOS, and CD31 was performed on days 3, 7, and 14. The length of reepithelialization was investigated on day 14. RESULTS: The combined therapy promoted faster wound healing than the other treatments. The expression levels of the proinflammatory factors IL-1ß, IL-6, monocyte chemoattractant protein-1 (MCP-1), and iNOS were reduced, and arginase-1 expression was increased compared with those in the other groups. The expression levels of vascular endothelial growth factor and CD31 in the NPWT-combined-with-AFT group were significantly higher than those in the other groups. Reepithelialization was faster in the NPWT-combined-with-AFT group (by day 14) than in the other groups. CONCLUSION: Combining NPWT and AFT can enhance diabetic wound healing by improving wound inflammation and increasing wound vascularization. CLINICAL RELEVANCE STATEMENT: The authors designed a randomized controlled trial of diabetic rats to confirm that NPWT can enhance the vascularization and improve inflammation of the diabetic wound after the autologous fat transplantation treatment. This article may provide a new idea for treating diabetic wounds.

Sustained notch signaling inhibition with a gamma-secretase inhibitor prevents traumatic heterotopic ossification.

Background: Traumatic heterotopic ossification (THO) is a devastating sequela following traumatic injuries and orthopedic surgeries. To date, the exact molecular mechanism of THO formation is still unclear, which hinders the development of effective treatments. The process of THO formation is believed to recapitulate a series of spatiotemporal cellular and signaling events that occur during skeletal development. The Notch signaling pathway is a critical genetic regulator in embryological bone development and fracture healing. However, few data are available concerning whether Notch signaling regulates THO development and maturation. Methods: We firstly detected the expressions of Notch target genes in both mouse and human THO samples with quantitative RT-PCR and immunohistochemistry (IHC). Then, tissue-resident mesenchymal progenitor cells (TMPCs) were isolated, and the abilities of the proliferation and osteogenic and chondrogenic differentiation of TMPCs were examined under the intervention of the gamma-secretase inhibitor-DAPT at different time points. Finally, DAPT was also administrated in THO mice by burn and Achilles tenotomy injury, and ectopic cartilage and bone formation were monitored by histology and micro-CT. Results: Several Notch target genes were upregulated in both mouse and human THO tissues. Sustained Notch signaling inhibition by DAPT reduced proliferation, osteogenic and chondrogenic differentiation of TMPCs in a time-dependent manner. Moreover, DAPT administration within 3 weeks could inhibit ectopic cartilage and bone formation in a mouse THO model without affecting the total body bone mass. Conclusions: The Notch signaling serves as an important therapeutic target during THO formation. And sustained gamma-secretase inhibition by DAPT has great potential in repressing chondrogenic and osteogenic differentiation of TMPCs, as well as inhibited ectopic cartilage and bone formation in vivo. The translational potential of this article: Sustained Notch inhibition via systemic DAPT (or other similar gamma-secretase inhibitors) administration has promising clinical utility for inhibiting THO formation, providing new insight into THO prophylaxis and treatment.

NIR-triggered photodynamic therapy of traumatic heterotopic ossification with a type II collagen-targeted photosensitizer.

Traumatic heterotopic ossification (HO) represents an intractable sequela following trauma with no currently effective prophylaxis or treatment. Photodynamic therapy (PDT) is a non-invasive treatment for various proliferative diseases. However, the specific effects of PDT on HO development remain unclear. In this study, the therapeutic potential of a near-infrared (NIR) probe-WL-808, composed of type II collagen-binding peptide (WYRGRL) and a PDT photosensitizer (IR-808), was evaluated for the innovative HO-targeted PDT approach. In vitro studies indicated that WL-808 could induce chondrocyte apoptosis and inhibit cell viability through ROS generation under NIR excitation. In vivo, the efficacy of WL-808-mediated PDT was tested on the tenotomy HO model mice. WL-808 specifically targeted the type II collagen cartilaginous template of HO, promoting cell apoptosis and enhancing extracellular matrix (ECM) degradation under 808 nm NIR excitation, which inhibited the final ectopic bone formation. Moreover, no obvious toxicity or side effects were detected after treatment with WL-808. Taken together, WL-808-mediated PDT significantly diminished ectopic cartilage and subsequent bone formation, providing a new perspective for HO prophylaxis and treatment.