Comparison of different treatment approaches for coronoid process fracture in terrible triad injury: a multicenter, randomized controlled study.

PURPOSE: The purpose of the study was to compare the functional results of different treatment approaches for the fracture of the coronoid process in terrible triad injury (TTI). METHODS: This prospective randomized controlled trial included participants from seven level-1 trauma centres in China. All patients were randomly assigned to three groups, wherein different approaches were applied to treat coronoid fracture: group A) internal fixation of the coronoid process without external fixation or splint (ORIF group), B) external fixation using a hinged fixator without internal fixation (Exfix group), and C) long-arm plaster for two to three weeks postoperatively without internal fixation of coronoid process (Plaster group). Early active motion exercises within the limits of pain were started immediately after surgery under the supervision of a physical therapist. Outcomes were evaluated at regular intervals over the subsequent 12 months. RESULTS: A total of 65 patients (22 patients in Group A, 21 in Group B, and 22 in Group C) were included in this trial from January 2016 to January 2019. The average arc of elbow motion was 114.1° ± 8.92°. The average flexion and flexion contracture were 126.4° ± 11.2° and 12.3° ± 7.7°, respectively. The arcs of forearm rotation of the elbow for each group were 145.41° ± 9.36°, 143.38° ± 9.79°, and 143.86° ± 10.95°, respectively. The MEPS for each group were 86.82 ± 9.7, 86.67 ± 9.92, and 85.23 ± 8.66, respectively. The DASH score for each group were 18.26 ± 19.31, 18.85 ± 15.02, and 20.19 ± 13.59, respectively. CONCLUSION: All three approaches in our trial showed similar functional results in the long-term survey. Patients treated with external fixation without internal fixation of the coronoid process showed less pain during early mobilization and acquired maximum flexion within a short duration after surgery.

Cancellous bone allograft is comparable to fibular strut allograft for augmentation in three- or four-part proximal humeral fractures.

BACKGROUND: Bone grafts have been used for augmentation and improving stability of reduced fractures in proximal humeral fractures. The aim of this study was to analyze the clinical and radiological outcomes after the use of cancellous bone allografts (CAs) for augmentation in 3- or 4-part proximal humeral fractures, and compare with fibular strut allografts (FAs). METHODS: Between November 2016 and February 2018, 55 patients, followed for at least 1 year, with 3- or 4-part proximal humeral fractures fixed with locking plates were included and grouped according to the type of allograft bone used for augmentation. In this retrospective analysis, we assessed and compared the clinical and radiological outcomes of the 2 groups, using the visual analog scale score, the Constant-Murley score (CMS), the disability of the arm, shoulder, and hand (DASH) score, the range of movement, neck-shaft angle (NSA), humeral head height (HHH), and the changes of NSA and HHH, as well as recording any complications. The repeatedly measured clinical and radiological outcomes were analyzed by linear mixed models. The differences in outcomes between groups at the final follow-up were compared using Student's t test. RESULTS: There were 28 patients in the CA group and 27 patients in the FA group with an average follow-up of 14.5 months. The mean age of all patients was 64 (36-86). Nonsignificant group effects were observed on CMS (ß = -8.792, P = .216), DASH (ß = 1.329, P = .094), NSA (ß = 1.432, P = .752), and HHH (ß = 1.660, P = .628). At the final follow-up, the patients in the CA group showed no significant differences in visual analog scale (1.8 vs. 2.2, P = .276), CMS (81.5 vs. 75.4, P = .072), and DASH (11.0 vs. 13.5, P = .235) scores compared with the FA group. There were no significant differences in the change of NSA (6 vs. 4, P = .387) or HHH (1 vs. 2, P = .261). CONCLUSIONS: Patients with 3- or 4-part proximal humeral fractures treated with locking plates combined with CAs have good clinical and radiographic outcomes, similar to those treated with FAs.

High-Order Assembly toward Polysaccharide-Based Complex Coacervate Nanodroplets Capable of Targeting Cancer Cells.

High-order assembly plays a significant role in the formation of living organisms containing a large number of biomacromolecules and, thus, enlightens the construction of nanomaterials that can load macromolecular payloads at a high efficiency. Herein, by choosing anionic hyaluronic acid (HA) as a model payload, we demonstrated how the electrostatic-interaction-induced high-order assembly can be used to load efficiently biomacromolecules into complex coacervate nanodroplets. The resultant assemblies were primarily composed of HA and cationic chitosan oligosaccharide/dextran (COS/Dex) nanogels and had a controllable structure while also exhibiting biological functionality. HA in the assemblies is capable of targeting CD44-overexpressed tumor cells through CD44-mediated endocytic pathways, which are elucidated herein. Therefore, this study provides a reliable approach for the efficient loading of macromolecular payloads into complex coacervate nanodroplets via electrostatic-attraction-induced high-order assembly.

Anatomic study of coracoclavicular ligaments for reconstruction of acromioclavicular joint dislocations.

BACKGROUND: There has been a trend to reconstruct the coracoclavicular (CC) ligaments anatomically for management of acromioclavicular (AC) joint dislocations. PURPOSE: The aim of this study was to determine the location and orientation of the CC ligaments for anatomic reconstruction of the AC joint. METHODS: The subjects were a total of 40 shoulders from 20 Chinese cadavers. Two K-wires were drilled through the insertion center of the conoid and trapezoid ligaments respectively. The distance from the center of the CC ligaments to the bone landmarks of the clavicle and the oblique angle of the two K-wires was measured respectively. RESULTS: The distance from the center of the trapezoid ligament to the lateral end and the anterior border of the clavicle was 21.7 ± 1.1 mm and 6.4 ± 0.5 mm, respectively. The valgus angle and retroversion angle of the trapezoid ligament was 39.3°±0.9° and 6.0°±0.6°, respectively. The distance from the center of the conoid ligament to the lateral end and the posterior border of the clavicle was 36.6 ± 0.9 mm and 5.5 ± 0.4 mm, respectively. The valgus angle and retroversion angle of the conoid ligament was 6.6°±0.7° and 11.0°±0.9°, respectively. CONCLUSIONS: These findings are important for the anatomic reconstruction of the AC joint dislocations, by predicting the location and orientation of the conoid and trapezoid ligaments accurately.

Effect of Fibular Allograft Augmentation in Medial Column Comminuted Proximal Humeral Fractures: A Randomized Controlled Trial.

BACKGROUND: Previous observational studies and meta-analyses have recommended augmentation with a fibular allograft (FA) during the treatment of proximal humeral fractures with locking plates (LPs). However, to our knowledge, randomized controlled trials comparing open reduction and internal fixation (ORIF) with and without FA have not been performed to date. METHODS: This was a randomized controlled trial in which adults with a medial column comminuted proximal humeral fracture were randomly allocated to undergo ORIF with an LP (the LP group) or with an LP augmented with an FA (the FA group). Patients were followed for 24 months. The primary outcome was the Disabilities of the Arm, Shoulder and Hand (DASH) score at 12 months after the surgical procedure. The secondary outcomes included the DASH score at other time points, shoulder function, pain score, satisfaction, complications, and changes in neck-shaft angle and humeral head height. RESULTS: From October 20, 2016, to December 24, 2019, 80 patients were randomized. There were 52 women (65%), and the mean patient age (and standard deviation) was 65 ± 14 years. Of the 80 patients, 39 were allocated to the FA group and 41 were allocated to the LP group. At the primary time point (12 months), the unadjusted mean between-group difference in DASH score was -1.2 (95% confidence interval [CI], -7.3 to 5.0; p = 0.71) favoring the FA group, and, with adjustment for smoking, alcohol drinking, and diabetes, the between-group difference was -1.4 (95% CI, -7.7 to 5.0; p = 0.67) favoring FA. No significant differences between the 2 groups were found among the secondary outcomes. CONCLUSIONS: No additional benefit was found for FA augmentation in treating medial column comminuted proximal humeral fractures. LEVEL OF EVIDENCE: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Double-network hydrogel enhanced by SS31-loaded mesoporous polydopamine nanoparticles: Symphonic collaboration of near-infrared photothermal antibacterial effect and mitochondrial maintenance for full-thickness wound healing in diabetes mellitus.

Diabetic wound healing has become a serious healthcare challenge. The high-glucose environment leads to persistent bacterial infection and mitochondrial dysfunction, resulting in chronic inflammation, abnormal vascular function, and tissue necrosis. To solve these issues, we developed a double-network hydrogel, constructed with pluronic F127 diacrylate (F127DA) and hyaluronic acid methacrylate (HAMA), and enhanced by SS31-loaded mesoporous polydopamine nanoparticles (MPDA NPs). As components, SS31, a mitochondria-targeted peptide, maintains mitochondrial function, reduces mitochondrial reactive oxygen species (ROS) and thus regulates macrophage polarization, as well as promoting cell proliferation and migration, while MPDA NPs not only scavenge ROS and exert an anti-bacterial effect by photothermal treatment under near-infrared light irradiation, but also control release of SS31 in response to ROS. This F127DA/HAMA-MPDA@SS31 (FH-M@S) hydrogel has characteristics of adhesion, superior biocompatibility and mechanical properties which can adapt to irregular wounds at different body sites and provide sustained release of MPDA@SS31 (M@S) NPs. In addition, in a diabetic rat full thickness skin defect model, the FH-M@S hydrogel promoted macrophage M2 polarization, collagen deposition, neovascularization and wound healing. Therefore, the FH-M@S hydrogel exhibits promising therapeutic potential for skin regeneration.

A Photoannealed Granular Hydrogel Facilitating Hyaline Cartilage Regeneration via Improving Chondrogenic Phenotype.

Hydrogel-based chondrocyte implantation presents a promising tissue engineering strategy for cartilage repair. However, the widely used elastic hydrogels usually restrict cell volume expansion and induce the dedifferentiation of encapsulated chondrocytes. To address this limitation, a photoannealed granular hydrogel (GH) composed of hyaluronic acid, polyethylene glycol, and gelatin was formulated for cartilage regeneration in this study. The unannealed GH prepared by Diels-Alder cross-linked microgels could be mixed with chondrocytes and delivered to cartilage defects by injection, after which light was introduced to anneal the scaffold, leading to the formation of a stable and microporous chondrocyte deploying scaffold. The in vitro studies showed that GH could promote the volume expansion and morphology recovery of chondrocytes and significantly improve their chondrogenic phenotype compared to the nongranular hydrogel (nGH) with similar compositions. Further in vivo studies of subcutaneous culture and the rat full-thickness cartilage defect model proved that chondrocyte loaded GH could significantly stimulate hyaline cartilage matrix deposition and connection, therefore facilitating hyaline-like cartilage regeneration. Finally, the mechanistic study revealed that GH might improve chondrogenic phenotype via activating the AMP-activated protein kinase/glycolysis axis. This study proves the great feasibility of GHs as in situ chondrocyte deploying scaffolds for cartilage regeneration and brings new insights in designing hydrogel scaffold for cartilage tissue engineering.

[Preliminary application study of dual-robotic navigated minimally invasive treatment by TiRobot and Artis Zeego on pelvic fractures].

Objective: To summarize the surgical learning curve and preliminary operative experience of dual-robotic navigated minimally invasive treatment on pelvic fractures by TiRobot and Artis Zeego. Methods: Between July 2019 and February 2021, 90 patients with pelvic fractures were treated with dual-robotic navigated minimally invasive surgery by TiRobot and Artis Zeego. There were 64 males and 26 females, with an average age of 46.5 years (range, 13-78 years). Body mass index was 14.67-32.66 kg/m 2 (mean, 23.61 kg/m 2). Causes of injuries included traffic accident in 43 cases, falling from height in 37 cases, low-energy injuries such as flat falls in 10 cases. The interval between injury and surgery was 1-36 days (mean, 7.3 days). According to the location of the implanted screws, the patients were divided into sacroiliac screw group ( n=33), acetabular screw group (acetabulum anterior/posterior column, n=24), composite screws group (sacroiliac and acetabulum anterior/posterior column, n=33). According to the screw implantation time and accuracy, the surgical learning curve was plotted, and the differences in the relevant indicators between learning stage and skilled stage were compared. Results: All 90 patients successfully completed the operation, the intraoperative bleeding volume was 5-200 mL (median, 20 mL). There was no vascular or nerve injury. All incisions healed by first intention. The screw implantation time ranged from 7.5 to 33.0 minutes (mean, 18.92 minutes), and the screw implantation accuracy ranged from 1.1 to 1.8 mm (mean, 1.56 mm). According to the learning curve, the practice stage of 3 groups was reached after 7, 10, and 11 cases, respectively. With the accumulation of surgical experience, the screw implantation time had a significant downward trend. Compared with the learning stage, the screw implantation time on skilled stage in 3 groups significantly shortened ( P<0.05), but the difference in the screw implantation accuracy was not significant ( P>0.05). Conclusion: TiRobot and Artis Zeego assisted pelvic fracture surgery is safe and efficient, which helps the surgeon to quickly master the pelvic channel screw surgery, and the operation time is significantly shortened on the premise of ensuring the implantation accuracy.

In vivo prevascularization strategy enhances neovascularization of ß-tricalcium phosphate scaffolds in bone regeneration.

Background: Neovascularization is critical for bone regeneration. Numerous studies have explored prevascularization preimplant strategies, ranging from calcium phosphate cement (CPC) scaffolds to co-culturing CPCs with stem cells. The aim of the present study was to evaluate an alternative in vivo prevascularization approach, using preimplant-prepared macroporous beta-tricalcium phosphate (ß-TCP) scaffolds and subsequent transplantation in bone defect model. Methods: The morphology of ß-TCPs was characterized by scanning electron microscopy. After 3 weeks of prevascularization within a muscle pouch at the lateral size of rat tibia, we transplanted prevascularized macroporous ß-TCPs in segmental tibia defects, using blank ß-TCPs as a control. Extent of neovascularization was determined by angiography and immunohistochemical (IHC) evaluations. Tibia samples were collected at different time points for biomechanical, radiological, and histological analyses. RT-PCR and western blotting were used to evaluate angio- and osteo-specific markers. Results: With macroporous ß-TCPs, we documented more vascular and supporting tissue invasion in the macroporous ß-TCPs with prior in vivo prevascularization. Radiography, biomechanical, IHC, and histological analyses revealed considerably more vascularity and bone consolidation in ß-TCP scaffolds that had undergone the prevascularization step compared to the blank ß-TCP scaffolds. Moreover, the prevascularization treatment remarkably upregulated mRNA and protein expression of BMP2 and vascular endothelial growth factor (VEGF) during bone regeneration. Conclusion: This novel in vivo prevascularization strategy successfully accelerated vascular formation to bone regeneration. Our findings indicate that prevascularized tissue-engineered bone grafts have promising potential in clinical applications. The translational potential of this article: This study indicates a novel in vivo prevascularization strategy for growing vasculature on ß-TCP scaffolds to be used for repair of large segmental bone defects, might serve as a promising tissue-engineered bone grafts in the future.

The neck-shaft angle is the key factor for the positioning of calcar screw when treating proximal humeral fractures with a locking plate.

AIMS: The aim of this study was to explore why some calcar screws are malpositioned when a proximal humeral fracture is treated by internal fixation with a locking plate, and to identify risk factors for this phenomenon. Some suggestions can be made of ways to avoid this error. METHODS: We retrospectively identified all proximal humeral fractures treated in our institution between October 2016 and October 2018 using the hospital information system. The patients' medical and radiological data were collected, and we divided potential risk factors into two groups: preoperative factors and intraoperative factors. Preoperative factors included age, sex, height, weight, body mass index, proximal humeral bone mineral density, type of fracture, the condition of the medial hinge, and medial metaphyseal head extension. Intraoperative factors included the grade of surgeon, neck-shaft angle after reduction, humeral head height, restoration of medial support, and quality of reduction. Adjusted binary logistic regression and multivariate logistic regression models were used to identify pre- and intraoperative risk factors. Area under the curve (AUC) analysis was used to evaluate the discriminative ability of the multivariable model. RESULTS: Data from 203 patients (63 males and 140 females) with a mean age of 62 years (22 to 89) were analyzed. In 49 fractures, the calcar screw was considered to be malpositioned; in 154 it was in the optimal position. The rate of malpositioning was therefore 24% (49/203). No preoperative risk factor was found for malpositioning of the calcar screws. Only the neck-shaft angle was found to be related to the risk of screw malpositioning in a multivariate model (with an AUC of 0.72). For the fractures in which the neck-shaft angle was reduced to between 130° and 150°, 91% (133/46) of calcar screws were in the optimal position. CONCLUSION: The neck-shaft angle is the key factor for the appropriate positioning of calcar screws when treating a proximal humeral fracture with a locking plate. We recommend reducing the angle to between 130° and 150°. Cite this article: Bone Joint J 2020;102-B(12):1629-1635.

Locking Plate Use with or without Strut Support for Varus Displaced Proximal Humeral Fractures in Elderly Patients.

Varus displaced fractures of the proximal part of the humerus, particularly in osteoporotic bone, commonly require open reduction and internal fixation. However, surgical treatment methods remain controversial and have shown inconsistent results. A fibular allograft for indirect medial reduction and strut support has been used in an effort to prevent secondary postoperative varus displacement. However, the long-term outcomes of this method require confirmation. We hypothesized that placing a fibular strut parallel to the calcar screw could increase the biomechanical stability of the medial hinge, thus preventing secondary varus deformity. In the present study, we compared the clinical outcomes of locking plate use with and without medial strut support with use of a fibular allograft for the treatment of varus humeral fractures in patients ≥65 years old. METHODS: We compared 2 different graft techniques involving the use of fibular allografts in elderly patients with varus displaced proximal humeral fractures who underwent open reduction and internal fixation. The patients were divided into 3 groups: (1) the intramedullary graft group (Group A), (2) the medial hinge support group (Group B), and (3) the locking plate alone group (Group C). Clinical outcomes included the final varus angulation of the humeral head, the occurrence of major complications (screw cut-out or cut-through or osteonecrosis), and the American Shoulder and Elbow Surgeons (ASES) score at 1 year after treatment. RESULTS: A total of 128 patients were included in our study. The final varus angles were 14.7°, 13.1°, and 18.6°, for the intramedullary graft group, the medial hinge support group, and locking plate alone group, respectively. The mean ASES scores were 87.2, 88.6, and 82.2, respectively. There were differences in ASES scores between Group A and Group C as well as also between Group B and Group C. Fewer major complications were found in patients managed with locking plates in combination with intramedullary graft or medial hinge support (Group A and Group B) than in patients managed with locking plates alone (Group C). CONCLUSIONS: The use of a locking plate in combination with medial strut support with use of a fibular allograft reduced complications when used for the treatment of varus displaced proximal humeral fractures in elderly patients in comparison with the use of a locking plate alone. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Extracellular vesicle-mimetic nanovesicles transport LncRNA-H19 as competing endogenous RNA for the treatment of diabetic wounds.

Diabetic wounds, one of the most enervating complications of diabetes mellitus, affect millions of people worldwide annually. Vascular insufficiency, caused by hyperglycemia, is one of the primary causes and categories of diabetic impaired wound healing. Recently, long noncoding RNA (LncRNA)-H19, which is significantly decreased in diabetes and may be crucial in triggering angiogenesis, has attracted increasing interest. The possible relationship between the decrease of LncRNA-H19 and the impairment of angiogenesis in diabetes could involve impairment of the insulin-phosphatidylinositol 3-kinase (PI3K)-Akt pathway via the interdiction of LncRNA-H19. Thus, a therapeutic strategy utilizing LncRNA-H19 delivery is feasible. In this study, we investigated the possibility of using high-yield extracellular vesicle-mimetic nanovesicles (EMNVs) as an effective nano-drug delivery system for LncRNA, and studied the function of EMNVs with a high content of LncRNA-H19 (H19EMNVs). The results, which were exciting, showed that H19EMNVs had a strong ability to neutralize the regeneration-inhibiting effect of hyperglycemia, and could remarkably accelerate the healing processes of chronic wounds. Our results suggest that bioengineered EMNVs can serve as a powerful instrument to effectively deliver LncRNA and will be an extremely promising multifunctional drug delivery system in the immediate future.

[Nutrient artery entrance on the posterolateral wall of thoracic vertebral bodies: another potential landmark for vertebral screw insertion].

OBJECTIVE: To evaluate an alternative landmark for thoracic vertebral screw insertion using the nutrient artery entrance on the posterolateral wall of thoracic vertebral bodies, and to discuss its clinical significance. METHODS: Twenty normal adult cadaver thoracic vertebral specimens were obtained randomly. Measurements included the number of nutrient artery entrance on left and right wall of thoracic vertebral bodies from T5 to T12, the diameter of the maximal nutrient artery entrance (d), the distance from nutrient artery entrance to the superior (A) or posterior (B) margin of the vertebral body, the distance between the posterior edge of the vertebral body and the nutrient artery entrance line (C) or the upper costal facet line (D). The length between left and right nutrient artery entrance (a) or costal facet (b) was measured too. RESULTS: From T5 to T12, the nutrient artery entrance were all underneath the upper costal facet. There were no significant differences between left and right side of anatomic measurements of each vertebral body from T5 to T12. The distance of A increased from T5 to T12, and the diameter and distance of B were no significant differences from T5 to T12. There were significant differences between the value C and the value D from T5 to T10. CONCLUSIONS: The anatomical position of the nutrient artery entrance is relatively settled, and it could be used as a new landmark for screw placement.

Exosomes derived from human platelet-rich plasma prevent apoptosis induced by glucocorticoid-associated endoplasmic reticulum stress in rat osteonecrosis of the femoral head via the Akt/Bad/Bcl-2 signal pathway.

An excess of glucocorticoids (GCs) is reported to be one of the most common causes of osteonecrosis of the femoral head (ONFH). In addition, GCs can induce bone cell apoptosis through modulating endoplasmic reticulum (ER) stress. Among the three main signal pathways in ER stress, the PERK (protein kinase RNA-like ER kinase)/CHOP (CCAAT-enhancer-binding protein homologous protein) pathway has been considered to be closely associated with apoptosis. Platelet-rich plasma (PRP) has been referred to as a concentration of growth factors and the exosomes derived from PRP (PRP-Exos) have a similar effect to their parent material. The enriched growth factors can be encapsulated into PRP-Exos and activate Akt and Erk pathways to promote angiogenesis. Activation of the Akt pathway may promote the expression of anti-apoptotic proteins like Bcl-2, while CHOP can inhibit B-cell lymphoma 2 (Bcl-2) expression to increase the level of cleaved caspase-3 and lead to cell death. Consequently, we hypothesized that PRP-Exos prevent apoptosis induced by glucocorticoid-associated ER stress in rat ONFH via the Akt/Bad/Bcl-2 signal pathway. To verify this hypothesis, a dexamethasone (DEX)-treated in vitro cell model and methylprednisolone (MPS)-treated in vivo rat model were adopted. Characterization of PRP-Exos, and effects of PRP-Exos on proliferation, apoptosis, angiogenesis, and osteogenesis of cells treated with GCs in vitro and in vivo were examined. Furthermore, the mechanism by which PRP-Exos rescue the GC-induced apoptosis through the Akt/Bad/Bcl-2 pathway was also investigated. The results indicate that PRP-Exos have the capability to prevent GC-induced apoptosis in a rat model of ONFH by promoting Bcl-2 expression via the Akt/Bad/Bcl-2 signal pathway under ER stress.

Fabrication of hydroxyapatite/chitosan composite hydrogels loaded with exosomes derived from miR-126-3p overexpressed synovial mesenchymal stem cells for diabetic chronic wound healing.

The exploration of an effective diabetic chronic wound healing process still remains a great challenge. Herein, we used gene overexpression technology to obtain synovial mesenchymal stem cells (SMSCs) and the miR-126-3p highly expressed SMSCs (SMSCs-126). The exosomes derived from miR-126-3p overexpressed SMSCs (SMSCs-126-Exos) with a particle size of 85 nm were encapsulated in hydroxyapatite/chitosan (HAP-CS) composite hydrogels (HAP-CS-SMSCs-126-Exos) as wound dressings. The SMSCs-126-Exos, CS and low-crystallinity HAP nanorods with a length of 200 nm and a diameter of 50 nm are uniformly dispersed within the whole composite hydrogel. The HAP-CS-SMSCs-126-Exos possess the controlled release property of SMSCs-126-Exos for at least 6 days. The released SMSCs-126-Exos nanoparticles stimulate the proliferation and migration of human dermal fibroblasts and human dermal microvascular endothelial cells (HMEC-1). At the same time, the migration and capillary-network formation of HMEC-1 are promoted through the activation of MAPK/ERK and PI3K/AKT. In vivo tests demonstrate that the HAP-CS-SMSCs-126-Exos successfully promote wound surface re-epithelialization, accelerate angiogenesis, and expedite collagen maturity due to the presence of HAP, CS and SMSCs-126-Exos. Therefore, the HAP-CS-SMSCs-126-Exos possess great potential application for diabetic chronic wound healing, and especially provide the possibility of using exosomes derived from modified cells as a new approach to bring wonderful functionality and controllability in future chronic wound therapy.

An implantable electrical stimulator used for peripheral nerve rehabilitation in rats.

This study evaluated an implantable electrical stimulator using a sciatic nerve injury animal model, and ethological, electrophysiological and histological assessments. Forty Sprague-Dawley rats were used in the study, and were subjected to crushing of the right sciatic nerve with a micro-vessel clamp. Electrical stimulators were implanted in twenty of the rats (the implantation group), while the remaining twenty rats were assigned to the control group. At three and six weeks following the surgery, the sciatic nerve function index (SFI) and the motor nerve conduction velocity (MCV) were demonstrated to be significantly higher in the implantation group compared with the control group (P<0.05). Histological analysis, using hematoxylin and eosin (H&E) staining, showed the typical pathological atrophy, and an assessment of the nerve that had been crushed revealed distal axonal breakdown in the control group. These results suggest that the implantable electrical stimulator was effective, and was suitable for implantation in a Sprague-Dawley rat model.

An experimental study of artificial murine bladder reflex arc established by abdominal reflex.

BACKGROUND: The neurogenic bladder dysfunction caused by spinal cord injury is difficult to treat clinically. The aim of this research was to establish an artificial bladder reflex arc in rats through abdominal reflex pathway above the level of spinal cord injury, reinnervate the neurogenic bladder and restore bladder micturition. METHODS: The outcome was achieved by intradural microanastomosis of the right T13 ventral root to S2 ventral root with autogenous nerve grafting, leaving the right T13 dorsal root intact. Long-term function of the reflex arc was assessed from nerve electrophysiological data and intravesical pressure tests during 8 months postoperation. Horseradish peroxidase (HRP) tracing was performed to observe the effectiveness of the artificial reflex. RESULTS: Single stimulus (3 mA, 0.3 ms pulses, 20 Hz, 5-second duration) on the right T13 dorsal root resulted in evoked action potentials, raised intravesical pressures and bladder smooth muscle, compound action potential recorded from the right vesical plexus before and after the spinal cord transaction injury between L5 and S4 segmental in 12 Sprague-Dawley rats. There were HRP labelled cells in T13 ventral horn on the experimental side and in the intermediolateral nucleus on both sides of the L6-S4 segments after HRP injection. There was no HRP labelled cell in T13 ventral horn on the control side. CONCLUSION: Using the surviving somatic reflex above the level of spinal cord injury to reconstruct the bladder autonomous reflex arc by intradural microanastomosis of ventral root with a segment of autologous nerve grafting is practical in rats and may have clinical applications for humans.