An Adaptable Drug Delivery System Facilitates Peripheral Nerve Repair by Remodeling the Microenvironment.

The multifaceted process of nerve regeneration following damage remains a significant clinical issue, due to the lack of a favorable regenerative microenvironment and insufficient endogenous biochemical signaling. However, the current nerve grafts have limitations in functionality, as they require a greater capacity to effectively regulate the intricate microenvironment associated with nerve regeneration. In this regard, we proposed the construction of a functional artificial scaffold based on a "two-pronged" approach. The whole system was developed by encapsulating Tazarotene within nanomicelles formed through self-assembly of reactive oxygen species (ROS)-responsive amphiphilic triblock copolymer, all of which were further loaded into a thermosensitive injectable hydrogel. Notably, the hydrogel exhibits obvious temperature sensitivity at a concentration of 6 wt %, and the nanoparticles possess concentration-dependent H2O2-response capability with a controlled release profile in 48 h. The combined strategy promoted the repair of injured peripheral nerves, attributed to the dual role of the materials, which mainly involved providing structural support, modulating the immune microenvironment, and enhancing angiogenesis. Overall, this study opens up intriguing prospects in tissue engineering.

Exosomes Derived from Adipose Stem Cells Enhance Bone Fracture Healing via the Activation of the Wnt3a/ß-Catenin Signaling Pathway in Rats with Type 2 Diabetes Mellitus.

Nonunion and delayed union are common complications of diabetes mellitus that pose a serious health threat to people. There are many approaches that have been used to improve bone fracture healing. Recently, exosomes have been regarded as promising medical biomaterials for improving fracture healing. However, whether exosomes derived from adipose stem cells can promote bone fracture healing in diabetes mellitus remains unclear. In this study, adipose stem cells (ASCs) and exosomes derived from adipose stem cells (ASCs-exos) are isolated and identified. Additionally, we evaluate the in vitro and in vivo effects of ASCs-exos on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and bone repair and the regeneration in a rat model of nonunion via Western blotting, immunofluorescence assay, ALP staining, alizarin red staining, radiographic examination and histological analysis. Compared with controls, ASCs-exos promoted BMSC osteogenic differentiation. Additionally, the results of Western blotting, radiographic examination and histological analysis show that ASCs-exos improve the ability for fracture repair in the rat model of nonunion bone fracture healing. Moreover, our results further proved that ASCs-exos play a role in activating the Wnt3a/ß-catenin signaling pathway, which facilitates the osteogenic differentiation of BMSCs. All these results show that ASCs-exos enhance the osteogenic potential of BMSCs by activating the Wnt/ß-catenin signaling pathway, and also facilitate the ability for bone repair and regeneration in vivo, which provides a novel direction for fracture nonunion in diabetes mellitus treatment.

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.

Peptide-based semiconducting polymer nanoparticles for osteosarcoma-targeted NIR-II fluorescence/NIR-I photoacoustic dual-model imaging and photothermal/photodynamic therapies.

BACKGROUND: The overall survival rate of osteosarcoma (OS) patients has not been improved for 30 years, and the diagnosis and treatment of OS is still a critical issue. To improve OS treatment and prognosis, novel kinds of theranostic modalities are required. Molecular optical imaging and phototherapy, including photothermal therapy (PTT) and photodynamic therapy (PDT), are promising strategies for cancer theranostics that exhibit high imaging sensitivity as well as favorable therapeutic efficacy with minimal side effect. In this study, semiconducting polymer nanoparticles (SPN-PT) for OS-targeted PTT/PDT are designed and prepared, using a semiconducting polymer (PCPDTBT), providing fluorescent emission in the second near-infrared window (NIR-II, 1000 - 1700 nm) and photoacoustic (PA) signal in the first near-infrared window (NIR-I, 650 - 900 nm), served as the photosensitizer, and a polyethylene glycolylated (PEGylated) peptide PT, providing targeting ability to OS. RESULTS: The results showed that SPN-PT nanoparticles significantly accelerated OS-specific cellular uptake and enhanced therapeutic efficiency of PTT and PDT effects in OS cell lines and xenograft mouse models. SPN-PT carried out significant anti-tumor activities against OS both in vitro and in vivo. CONCLUSIONS: Peptide-based semiconducting polymer nanoparticles permit efficient NIR-II fluorescence/NIR-I PA dual-modal imaging and targeted PTT/PDT for OS.

A Novel Integrated Pharmacokinetic-Pharmacodynamic Model to Evaluate Combination Therapy and Determine In Vivo Synergism.

Understanding pharmacokinetic (PK)-pharmacodynamic (PD) relationships is essential in translational research. Existing PK-PD models for combination therapy lack consideration of quantitative contributions from individual drugs, whereas interaction factor is always assigned arbitrarily to one drug and overstretched for the determination of in vivo pharmacologic synergism. Herein, we report a novel generic PK-PD model for combination therapy by considering apparent contributions from individual drugs coadministered. Doxorubicin (Dox) and sorafenib (Sor) were used as model drugs whose PK data were obtained in mice and fit to two-compartment model. Xenograft tumor growth was biphasic in mice, and PD responses were described by three-compartment transit models. This PK-PD model revealed that Sor (contribution factor = 1.62) had much greater influence on overall tumor-growth inhibition than coadministered Dox (contribution factor = 0.644), which explains the mysterious clinical findings on remarkable benefits for patients with cancer when adding Sor to Dox treatment, whereas there were none when adding Dox to Sor therapy. Furthermore, the combination index method was integrated into this predictive PK-PD model for critical determination of in vivo pharmacologic synergism that cannot be correctly defined by the interaction factor in conventional models. In addition, this new PK-PD model was able to identify optimal dosage combination (e.g., doubling experimental Sor dose and reducing Dox dose by 50%) toward much greater degree of tumor-growth inhibition (>90%), which was consistent with stronger synergy (combination index = 0.298). These findings demonstrated the utilities of this new PK-PD model and reiterated the use of valid method for the assessment of in vivo synergism. SIGNIFICANCE STATEMENT: A novel pharmacokinetic (PK)-pharmacodynamic (PD) model was developed for the assessment of combination treatment by considering contributions from individual drugs, and combination index method was incorporated to critically define in vivo synergism. A greater contribution from sorafenib to tumor-growth inhibition than that of coadministered doxorubicin was identified, offering explanation for previously inexplicable clinical observations. This PK-PD model and strategy shall have broad applications to translational research on identifying optimal dosage combinations with stronger synergy toward improved therapeutic outcomes.

MiR-144-5p, an exosomal miRNA from bone marrow-derived macrophage in type 2 diabetes, impairs bone fracture healing via targeting Smad1.

BACKGROUND: Patients with diabetes have an increased risk of nonunion and delayed union of fractures. Macrophages have been shown as a key player in diabetic complications. However, it remains obscure how diabetic milieu affects macrophage-derived exosomes and its implications on osteogenic differentiation of BMSCs. In this study, we aim to define the impact of diabetic milieu on macrophage-derived exosomes, role of extracellular vesicles in intercellular communication with BMSCs, and subsequent effects on osteogenic differentiation and fracture repair. RESULTS: The osteogenic potential and the ability of fracture repair of exosomes derived from diabetic bone marrow-derived macrophages (dBMDM-exos) were revealed to be lower, as compared with non-diabetic bone marrow-derived macrophages (nBMDM-exos) in vitro and in vivo. Interestingly, miR-144-5p levels were sharply elevated in dBMDM-exos and it could be transferred into BMSCs to regulate bone regeneration by targeting Smad1. In addition, the adverse effects of dBMDM-exos on the osteogenic potential and the ability of fracture repair were reversed through the suppression of miR-144-5p inhibition in vitro and vivo. CONCLUSIONS: The results demonstrated an important role of exosomal miR-144-5p in bone regeneration, offering insight into developing new strategy for the improvement of fracture healing in patients with diabetes mellitus.

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.

Negative pressure wound therapy promotes muscle-derived stem cell osteogenic differentiation through MAPK pathway.

Negative pressure wound therapy (NPWT) has been revealed to be effective in the treatment of open fractures, although the underlying mechanism is not clear. This article aimed to investigate the effects of NPWT on muscle-derived stem cell (MDSC) osteoblastic differentiation and the related potential mechanism. The cell proliferation rate was substantially increased in NPWT-treated MDSCs in comparison with a static group for 3 days. There was no observable effect on the apoptosis of MDSC treated with NPWT compared with the control group for 3 days. The expression levels of HIF-1α, BMP-2, COL-I, OST and OPN were increased on days 3, 7 and 14, but the expression level of Runx2 was increased on days 3 and 7 in the NPWT group. Pre-treatment, the specific inhibitors were added into the MDSCs treated with NPWT and the control group. ALP activity and mineralization were reduced by inhibiting the ERK1/2, p38 and JNK pathways. The expression levels of Runx2, COL-I, OST and OPN genes and proteins were also decreased using the specific MAPK pathway inhibitors on days 3, 7 and 14. There were no significant effects on the expression of BMP-2 except on day 3. However, the expressions of the HIF-1α gene and protein slightly increased when the JNK pathway was inhibited. Therefore, NPWT promotes the proliferation and osteogenic differentiation of MDSCs through the MAPK pathway.

Bioengineered NRF2-siRNA Is Effective to Interfere with NRF2 Pathways and Improve Chemosensitivity of Human Cancer Cells.

The nuclear factor (erythroid-derived 2)-like 2 (NRF2) is a transcription factor in the regulation of many oxidative enzymes and efflux transporters critical for oxidative stress and cellular defense against xenobiotics. NRF2 is dysregulated in patient osteosarcoma (OS) tissues and correlates with therapeutic outcomes. Nevertheless, research on the NRF2 regulatory pathways and its potential as a therapeutic target is limited to the use of synthetic small interfering RNA (siRNA) carrying extensive artificial modifications. Herein, we report successful high-level expression of recombinant siRNA against NRF2 in Escherichia coli using our newly established noncoding RNA bioengineering technology, which was purified to >99% homogeneity using an anion-exchange fast protein liquid chromatography method. Bioengineered NRF2-siRNA was able to significantly knock down NRF2 mRNA and protein levels in human OS 143B and MG63 cells, and subsequently suppressed the expression of NRF2-regulated oxidative enzymes [heme oxygenase-1 and NAD(P)H:quinone oxidoreductase 1] and elevated intracellular levels of reactive oxygen species. In addition, recombinant NRF2-siRNA was effective to sensitize both 143B and MG63 cells to doxorubicin, cisplatin, and sorafenib, which was associated with significant downregulation of NRF2-targeted ATP-binding cassette (ABC) efflux transporters (ABCC3, ABCC4, and ABCG2). These findings support that targeting NRF2 signaling pathways may improve the sensitivity of cancer cells to chemotherapy, and bioengineered siRNA molecules should be added to current tools for related research.

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.

Multifunctional biomedical imaging in physiological and pathological conditions using a NIR-II probe.

Compared with imaging in the visible (400 - 650 nm) and near-infrared window I (NIR-I, 650 - 900 nm) regions, imaging in near-infrared window II (NIR-II, 1,000-1,700 nm) is a highly promising in vivo imaging modality with improved resolution and deeper tissue penetration. In this work, a small molecule NIR-II dye,5,5'-(1H,5H-benzo[1,2-c:4,5-c'] bis[1,2,5]thiadiazole)-4,8-diyl)bis(N,N-bis(4-(3-((tert-butyldimethylsilyl)oxy)propyl)phenyl) thiophen-2-amine), has been successfully encapsulated into phospholipid vesicles to prepare a probe CQS1000. Then this novel NIR-II probe has been studied for in vivo multifunctional biological imaging. Our results indicate that the NIR-II vesicle CQS1000 can noninvasively and dynamically visualize and monitor many physiological and pathological conditions of circulatory systems, including lymphatic drainage and routing, angiogenesis of tumor and vascular deformity such as arterial thrombus formation and ischemia with high spatial and temporal resolution. More importantly, by virtue of the favorable half-life of blood circulation of CQS1000, NIR-II imaging is capable of aiding us to accomplish precise resection of tumor such as osteosarcoma, and to accelerate the process of lymph nodes dissection to complete sentinel lymph node biopsy for better decision-making during the tumor surgery. Overall, CQS1000 is a highly promising NIR-II probe for multifunctional biomedical imaging in physiological and pathological conditions, surpassing traditional NIR-I imaging modality and pathologic assessments for clinical diagnosis and treatment.

Hierarchical Microspheres Constructed from Chitin Nanofibers Penetrated Hydroxyapatite Crystals for Bone Regeneration.

Chitin exists abundantly in crab and shrimp shells as the template of the minerals, which inspired us to mineralize it for fabricating bone grafting materials. In the present work, chitin nanofibrous microspheres were used as the matrix for in situ synthesis of hydroxyapatite (HA) crystals including microflakes, submicron-needles, and submicron-spheres, which were penetrated by long chitin nanofibers, leading to the hierarchical structure. The shape and size of the HA crystals could be controlled by changing the HA synthesis process. The tight interface adhesion between chitin and HA through the noncovanlent bonds occurred in the composite microspheres, and HAs were homogeneously dispersed and bounded to the chitin nanofibers. In our findings, the inherent biocompatibilities of the both chitin and HA contributed the bone cell adhesion and osteoconduction. Moreover, the chitin microsphere with submicron-needle and submicron-sphere HA crystals remarkably promoted in vitro cell adhesion and in vivo bone healing. It was demonstrated that rabbits with 1.5 cm radius defect were almost cured completely within three months in a growth factor- and cell-free state, as a result of the unique surface microstructure and biocompatibilities of the composite microspheres. The microsphere scaffold displayed excellent biofunctions and an appropriate biodegradability. This work opened up a new avenue to construct natural polymer-based organic-inorganic hybrid microspheres for bone regeneration.

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.

Management of osteonecrosis of the femoral head with pedicled iliac bone flap transfer: A multicenter study of 2190 patients.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) often affects young active adults and leads to destruction of the hip joint and disabling arthritis. Several procedures have been developed to arrest the progress of osteonecrosis and postpone the procedure of total hip replacement especially in young patients. The aim of this multicenter study was to analyze the results of the use of the vascularized iliac bone flap transfer for management of ONFH. METHODS: From January 1985 to December 2012, a total of 2190 patients (2690 hips) with the mean age of 43.15 years (ranging from 18 to 65 years) underwent hip-preserving surgery with the pedilced iliac bone flap transfer for management of ONFH with Ficat and Arlet stage II-IV in 8 hospitals. There were 1733 hips in stage II, 776 hips in stage III, and 181 hips in stage IV preoperatively. The complications were recorded. The outcomes were evaluated by radiograph, the Harris hip-scoring system (HHS). RESULTS: Postoperative complications occurred in 128 patients (5.84%). Among them, 25 patients had deep venous thromboses, 16 patients had sensory deficits, 40 patients had superficial infection and hematoma, and 47 patients had wound dehiscence. A total of 1912 patients (2179 hips) were followed up with a median time of 12 years (ranging from 5 to 25 years). There were 1787 hips with no radiographic osteonecrotic progress during follow-up, while osteonecrosis progress was observed in 186 hips with stage II (13.1%), 170 hips with stage III (25.6%) and 36 hips with stage IV (36.4%; P < .001). Two hundred fifteen hips (9.87%) in 203 patients were converted to THA during follow-up, including 19 hips with stage II (1.34%), 162 hips with stage III (24.4%), and 34 hips with stage IV (34.3%).The mean HHS at the end of follow-up was significantly improved when compared to preoperative mean HHS (83.63 ± 5.03 vs. 66.54 ± 6.05, P < .001). CONCLUSIONS: In this evaluation of a large series of cases, the vascularized iliac bone flap transfer showed good results for arresting the osteonecrosis progress and improving the hip function of patients with pre-collapse stages of ONFH.

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.

Comparative effectiveness study between negative pressure wound therapy and conventional wound dressing on perforator flap at the Chinese tertiary referral teaching hospital.

BACKGROUND: Perforator flap techniques with conventional wound dressing have being extensively used in the management of soft-tissue defects. However; the flap's survival rate is not always guaranteed and the wound healing time always long. The aim of this study was to investigate the clinical effectiveness use of a freshly transplanted perforator flap in conjunction with Vacuum-assisted closure (VAC) for better clinical outcomes. METHODS: A prospective, randomized, effectiveness study comparing the clinical outcomes of VAC versus traditional wrap and bandages for the treatment of open wounds that required hospital admission and operative debridement using perforator flaps, was carried out from March 1, 2014 to March 31, 2016 at Wuhan University Zhongnan Hospital. Fifty-one eligible patients were randomized into two groups; study group (perforator flaps covered by VAC) and control group (perforator flaps covered by traditional wrap and bandages). The measured clinical endpoints included the time of the first post-operative dressing change, pain visual analogical scale, perforator flap infection rate, 95% perforator flap healing time and percentage of survived perforator flap. RESULTS: There was no statistically significant difference in the demographic profiles in the two cohorts. There were statistically significant differences in the clinical endpoints in the two groups (p < 0.001; p < 0.05, Table 2). CONCLUSIONS: In summary, VAC combining with perforator flap technique, can diminish accumulated exudation of the transferring flap, protect against postoperative infection, prolong the interval between perforator flap relocation and first postoperative dressing change, decrease pain during removal of dressing, increase perforator flap survival rate, and shorten wound healing time, with a good aesthetic outcome, a good mobility and a satisfactory therapeutic result.

Complications of negative pressure wound therapy: a mini review.

Negative pressure wound therapy, with its wide indications and narrow contraindications, has been widely used for various complicated wounds. Despite its excellent properties in promoting wound healing, there are sporadic but increasing reports on the complications. These complications included bleeding, infection, pain, rupture of the heart, and death in the short term. When used for the long term, the therapy may decrease life quality, increase anxiety, and lead to malnutrition. In this review, we briefly summarize the complications of negative pressure wound therapy.

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.

Real-time visualization of skeletal muscle necrosis in mice and swine through NIR-II/I fluorescence imaging.

Avulsion often occurs in the limb due to heavy shearing forces which not only damage skeletal muscle but also main vessels, resulting in life-threatening muscle ischemia and necrosis. Defining muscle activity is vital for surgical repair. Currently, the color, capacity of blood, contractibility, and consistency (4C) are the primary principles for evaluating the activities of torn muscles. Based on clinical experiences, this standard turns out to be delayed diagnosis, which is not defined by specific parameters. Recently, near-infrared (NIR) fluorescence probes emitting within the second near-infrared window (NIR-II, 1000-1700 nm) have been widely used for non-invasive optical imaging because the tissue absorption and autofluorescence in the NIR-II region are negligible, thus allowing deeper penetration depths with micrometer-scale spatial resolution in vivo. As pathogenesis and development of muscle necrosis, necrosis-related protein may participate in this procedure. There is promising future for NIR-II to be used in evaluating muscle activity in avulsion. A new approach is developed based on experiments with mice and large animals (swine). Myoblasts were incubated with indocyanine green (ICG) to identify the necrosis muscles. The model of extremity damaged muscle was established for the real-time visualization and detection of developed necrosis muscle field under new equipment, both in balb/c mice (female) and long-haired swines. A visible NIR-II/I imaging system was first used in a large animal injured skeletal muscle-related model. Our NIR-II/I imaging system is suitable for evaluating the normal and injured skeletal muscle ICG cycle and pointing to the necrotic skeletal muscle tissue. NIR-II imaging is superior to NIR-I imaging in estimating skeletal muscle, best with 1100 nm filter. NIR-II fluorescence with 1100 nm filter is suitable for analyzing the progress of necrosis muscle tissue, leading to a new approach for intraoperative evaluation.