Orbital Soft Tissue Displacement After Blow-Out Fracture Repair Using Poly (L-Lactide-Co-Glycolide) Polymer Plates Based on Image Fusion Technique.

PURPOSE: To analyze the displacement of orbital soft tissue after blow-out fracture (BOF) repair with poly (L-lactide-co-glycolide) plates. MATERIALS AND METHODS: In this retrospective study, all patients who had undergone repair operations for orbital BOF from 2017 to 2021 were evaluated. Poly (L-lactide-co-glycolide) plates were used as repair materials. Preoperative and postoperative computed tomography images were integrated into the same coordinate system applying image fusion technique and were compared to determine the maximum displacement of orbital tissue after surgical repair. RESULTS: A total of 15 patients were included. Five were male, and 10 were female. Mean age was 33±16 years. Median waiting period was 18 (12-23) days. Six cases were medial wall fractures, 5 were floor fractures, and 4 were combined fractures. Maxillo-ethmoidal strut was involved in 4. Mean defect area was 176.52±108.48 mm 2 . Median interval between postoperative imaging examinations was 292 (223-600) days. Mean orbital tissue displacement was 2.6±1.8 mm. Using simple and multivariable linear regression analysis, the fracture defect area ( P =0.001) and maxillo-ethmoidal strut involvement ( P =0.013) were found to be significantly associated with orbital tissue displacement. Median orbital volume change was 0.804 (0.647-1.010) cm 3 . Average proptosis variation was 1.2±0.8 mm. CONCLUSIONS: Poly (L-lactide-co-glycolide) plates were more suitable for orbital BOF with small defect size. Those with large defect or maxillo-ethmoidal strut involved might have greater tissue displacements due to decline of supporting strength of poly (L-lactide-co-glycolide) plates.

Self-assembled supramolecular dispersive liquid-phase microextraction for concentration and determination of anthraquinone compounds in Rhubarb.

Self-assembled supramolecular dispersive liquid-phase microextraction combined with high-performance liquid chromatography was developed and introduced for simultaneous extraction and determination of the trace level rhein, chrysophanol, and physcion in Rhubarb. Compared with conventional dispersive liquid-phase microextraction, the proposed method used a self-assembled ternary supramolecular consisting of the mixed extraction solvent (heptanol and nonanol) and dispersant (acetone) to achieve high enrichment factors of target analytes. Several factors affecting performance were investigated and optimized, including the mixed extraction solvent, type and volume of the dispersant, the pH of sample phase, salt concentration, shaking time, volume of sample phase, centrifugation time, and rate. Meanwhile, the method mechanism of self-assembled supramolecular dispersive liquid-phase microextraction was analyzed and described. Under the optimized extraction conditions, the enrichment factors of rhein, chrysophanol, and physcion were 116.5, 325.9, and 356.1, respectively. Good linearities (r ≥ 0.9952) for all analytes, low limits of detection (less than 0.04 ng/mL), satisfactory precisions (0.1-8.9%), and accuracies (recoveries, 88.2-104.1%) were achieved. The experimental results showed that the approach was simple, fast, with short extraction time, high enrichment factors, good linearities, and low limits of detection.

Serial Z-plasty for Correction of Cicatricial Conjunctival Constriction Rings.

BACKGROUND: Cicatricial conjunctival constriction rings caused by trauma seriously influences visual function and causes blepharon deformities. The treatment of cicatricial conjunctival constriction rings is intractable. METHODS: A 45-year-old male presented severe cicatricial conjunctival constriction ring due to traffic accident injury. This 5-mm diameter constriction ring resulted in the patient's eyelid deformities, including eyelid ptosis, ectropion, and visual obstruction. The patient underwent primary surgery of serial conjunctival Z-plasty for correction of the constriction ring. Conjunctival constriction ring was corrected immediately after Z-plasy. Fornix deepening suturing was adopted to promote formation of fornix and correct eyelid ectropion. A secondary surgery of frontalis flap suspension was adopted to correct ptosis 6 months after Z-plasty. RESULTS: The patient achieved a satisfactory and symmetrical appearance with no recurrence of cicatricial conjunctival constriction and no other complications during the 6-month follow-up period. CONCLUSION: In this patient, the authors claimed that serial Z-plasty surgery can effectively be used for correction of cicatricial conjunctival constriction rings. No further material implantation was applied during the operation.

Effects of miR-31 on the osteogenesis of human mesenchymal stem cells.

Exploring the molecular mechanisms that regulate the osteogenesis of human mesenchymal stem cells (hMSCs) will bring us more efficient methods for improving the treatment of bone-related diseases. In this study, we analyzed the effects of miR-31 on the osteogenesis of hMSCs. The overexpression of miR-31 repressed the osteogenesis of hMSCs, whereas the downregulation enhanced this process. SATB2 was testified to be a direct target of miR-31, and its effects on the osteogenesis were also described. Most importantly, the knockdown of SATB2 attenuated miR-31's osteogenic effects. Taken together, our findings suggest that miR-31 regulates the osteogenesis of hMSCs by targeting SATB2.

Repair of orbital bone defects in canines using grafts of enriched autologous bone marrow stromal cells.

BACKGROUND: Bone tissue engineering is a new approach for the repair of orbital defects. The aim of the present study was to explore the feasibility of tissue-engineered bone constructed using bone marrow stromal cells (BMSCs) that were rapidly isolated and concentrated from bone marrow (BM) by the red cell lysis method, then combined with ß-tricalcium phosphate (ß-TCP) to create grafts used to restore orbital bone defects in canines. METHODS: In the experimental group, grafts were constructed using BMSCs obtained by red cell lysis from 20 ml bone marrow, combined with ß-TCP and BM via the custom-made stem cell-scaffold device, then used to repair 10 mm diameter medial orbital wall bony defects in canines. Results were compared with those in groups grafted with BM/ß-TCP or ß-TCP alone, or with defects left untreated as controls. The enrichment of BMSCs and nucleated cells (NCs) in the graft was calculated from the number in untreated bone marrow and in suspensions after red cell lysis. Spiral computed tomography (CT) scans were performed 1, 4, 12 and 24 weeks after implantation in all groups. Gross examination, micro-CT and histological measurements were performed 24 weeks after surgery. The results were analyzed to evaluate the efficacy of bone repair. RESULTS: The number of NCs and of colony-forming units within the scaffolds were increased 54.8 times and 53.4 times, respectively, compared with untreated bone marrow. In the BMSC-BM/ß-TCP group, CT examination revealed that the scaffolds were gradually absorbed and the bony defects were restored. Micro-CT and histological examination confirmed that the implantations led to good repair of the defects, with 6 out 8 orbital defects completely restored in the experimental group, while by contrast, the grafts in the control groups did not fully repair the bony defects, a difference which was statistically significant (p<0.05). CONCLUSIONS: Tissue-engineered bone, constructed using BMSCs isolated by red cell lysis of BM, can restore critical-sized orbital wall defects in canines.

Surgical repair of large orbital floor and medial wall fractures with destruction of the inferomedial strut: Initial experience with a combined endoscopy navigation technique.

The application of navigation and endoscope is an area of intense interest in the surgical repair of orbital fractures. This study explored the advantages of a combined endoscopy navigation technique (ENT) for repairing large orbital floor and medial wall fractures (OFMWFs) with destruction of the inferomedial strut (IMS). Fifty-two consecutive patients with large OFMWFs with the destruction of the IMS underwent ENT-assisted surgical repair from January 2013 to February 2016. Patient demographics, causes of injury, clinical features, imaging data, and follow-up information (diplopia, ocular dysmotility, enophthalmos, infraorbital hypoesthesia, and other conditions) were collected and analyzed. Orbital volumes and implant positions were also evaluated. The median follow-up duration was 21 (range, 16-29) months. At the end of the follow-up visits, orbital reconstruction was demonstrated by orbital computed tomography. Of the 30 patients with diplopia within the 30-degree visual field of gaze, 27 (90%) reached diplopia remission. Of 40 patients, 34 (85%) achieved complete elimination of ocular dysmotility. Of 47 patients with enophthalmos of >2 mm, 43 (91%) acquired good symmetry with a mean improvement of 3.00 ± 1.00 mm. Of 33 patients, 27 (82%) recovered from infraorbital hypoesthesia. The postoperative orbital volumes of the two sides showed no significant differences (p = 0.087, paired t-test). Early surgical repair showed better outcomes of diplopia, ocular motility, and enophthalmos than late repair (p = 0.001, p = 0.007, and p = 0.000, generalized estimated equations). No patient developed surgery-related complications of visual acuity compromise, strabismus, ectropion, entropion, or lacrimal canaliculus injuries. ENT-assisted surgery appears to be safe, precise, and effective for the repair of large OFMWFs with destruction of the IMS.

Long-term outcomes of a new anatomy-based method for finding the medial cut end during late canalicular repair.

BACKGROUND: Locating the medial cut end during late repair of canalicular lacerations can be challenging. OBJECTIVE: The aim of this study was to evaluate the effectiveness and long-term outcomes of a new anatomy-based method for solving the problem of locating the medial cut end. METHODS: This retrospective interventional study included 85 eyes of 85 consecutive adult patients with unilateral inferior canalicular lacerations who underwent late primary (≥2 days after injury) or secondary (≥6 months after initial treatment) surgery. Before surgery, the lacerations were classified as lateral, central, or medial according to the 'distance from the punctum to the distal end' of the lacerated inferior canaliculus. The time spent to locate the proximal lacerated end (TSL) was recorded. All patients were followed up for ≥1 year to evaluate the lacrimal passage patency and the distance between the superior and inferior punctum (DBSIP, to assess cosmesis). RESULTS: There were 16 (18.82%) lateral-type, 55 (64.71%) central-type, and 14 (16.47%) medial-type canalicular lacerations. The TSL was 3.48 ± 1.05 (range 0.9-6.8) min for all patients and differed significantly among the three types of canalicular lacerations (P < 0.001). Lacrimal irrigation showed patent lacrimal passages in 69 patients (81.18%) at 3 months and a further 4 patients (4.71%) at 6 months, residual stenosis without obstruction in 5 patients (5.88%), and obstruction in 7 patients (8.24%). The postoperative DBSIP on the affected side was shorter than the preoperative DBSIP (2.66 ± 0.66 vs. 3.09 ± 1.72 mm, P = 0.006) and comparable to that on the unaffected side (2.78 ± 0.40 mm). CONCLUSION: Our new anatomy-based method is efficient and achieves good long-term outcomes for all types of late canalicular repair.

One-stage replacement surgery of orbital implants with noninfectious complications.

Orbital implant-associated complications always affect patients, resulting in multiple operations. One-stage replacement of complicated implants has been attractive for reducing operation times and preventing long-time appearance without artificial eye. We retrospectively analyzed the outcomes of 1-stage replacement surgery of orbital implant. A total of 21 eyes in 21 cases with noninfectious complications, who failed conservative therapies and surgical repairs, were treated with 1-stage orbital implant replacement. After a detailed ophthalmic history was obtained and examinations performed, patients with apparent purulent secretion in conjunctival sac were excluded. The preexisting orbital implant was carefully removed, and a new hydroxyapatite sphere was implanted simultaneously. Wound healing status, prosthesis movement, and cosmetic features were evaluated and recorded after at least 6 months' follow-up. Orbital implant exposure(16 cases) was the main indication of the replacement surgery; other causes included superior orbital area depression (2 cases), conjunctival fistula (1 case), orbital implant malposition (1 case), and the metal material of implant obstructing magnetic resonance imaging scan in 1 case. Eye-socket hollow was redressed in all cases immediately, and 95.23% cases (20/21) could wear an artificial eye and had a good cosmetic appearance, whereas conjunctival sac fistula reoccurred in 1 patient, and the implant was removed ultimately. Conjunctival sac constrictions occurred in 4 cases after operation and were treated by secondary conjunctival sac reconstruction 6 months later. In conclusion, 1-stage replacement of orbital implants offers an effective and efficient strategy for dealing with severe postimplantation noninfectious complications in achieving a symmetrically cosmetic appearance without delay.

Palpebral lipogranuloma caused by transcanalicular ointment injection after laser canaliculoplasty.

PURPOSE: Laser canaliculoplasty is widely used to treat lacrimal duct obstruction. We describe 12 patients in whom eyelid lipogranuloma developed subsequent to laser canaliculoplasty, followed by tobramycin and dexamethasone, ofloxacin, or erythromycin ointment injected in the lacrimal duct. METHODS: Clinical history, ocular workup, and CT were performed. Histopathologic examination was performed after eyelid tissue excision. RESULTS: Over a period of 3 years, 12 patients were diagnosed with eyelid lipogranuloma caused by diffusion and deposition of ointment. Seven of 12 patients were injected with tobramycin and dexamethasone ointment, 3 patients were injected with ofloxacin ointment, and 2 patients were injected with erythromycin ointment. Histopathologic features of the excised tissue included multifocal spaces surrounded by multinucleated giant cells, considered to be lipogranulomatous inflammation. CONCLUSIONS: The incidence of lipogranuloma caused by transcanalicular ointment injection after laser canaliculoplasty is low. Surgical excision of the lipogranuloma should be performed only when it becomes relatively localized and has passed the acute phase of inflammation to avoid the recurrence of lipogranuloma and diffusion of the inflammation. A cosmetic outcome should be considered, and simultaneous blepharoplasty with transplantation of herniated fat pads may be performed in either or both eyelids to achieve a satisfactory appearance. Injection of ointment in the lacrimal duct should be avoided, as it might create unnecessary complications when a new channel is created or when canalicular walls are penetrated. Local massage after ointment injection is not recommended.

Reconstruction of severe anophthalmic orbits and atresic eye sockets after enucleation and irradiation of retinoblastoma by vascular anastomosed free dorsalis pedis flaps' transplantation.

Retinoblastoma is a common malignant intraocular tumor in childhood, and most patients require enucleation or exenteration even with irradiation. Severe anophthalmic orbits and atresic eye sockets are not rare. We conducted a retrospective study to evaluate the results of surgical management of reconstruction of severe anophthalmic orbits and atresic eye sockets with vascular anastomosed free dorsalis pedis flap transplantation. There were 5 patients (5 eyes) who underwent reconstructive surgery of severe anophthalmic orbits and atresic eye sockets after enucleation and irradiation of retinoblastoma in our hospital during the 3 years. All patients had enucleation and irradiation immediately after the retinoblastoma was diagnosed and had never worn artificial eyes because of the atresic eye sockets. Vascular anastomosed free dorsalis pedis flaps, whose dimensions were typically 6.5 × 5.5 cm(2), were transplanted to reconstruct the severe anophthalmic orbits and atresic eye sockets. The donor sites were covered by free abdominal skin flaps. All the vascular anastomosed free dorsalis pedis flaps were valid after more than 6 months of follow-up. And then all the 5 patients underwent secondary autogenous dermal fat implantation to augment the supraorbital area depression. After the 2-stage reconstruction surgery, the dimensions of the eye sockets were adequate, and all patients were able to wear their prosthesis and had a satisfactory cosmetic result. Implantation of alloplastic materials is not recommended because of insufficient blood supply of the irradiated orbital area.

[Three-dimensionally preformed titanium mesh plates for posttraumatic complex orbital bone fracture reconstruction].

OBJECTIVE: To evaluate the outcomes of the clinical application of three-dimensionally preformed titanium mesh plates for posttraumatic complex orbital bone fracture reconstruction. METHODS: Thirteen patients (13 eyes) manifested with complex orbital fractures (including orbital-zygomatic-maxillary bone fracture in 6 patients, nasal-orbital-ethmoid bone fracture in 5 patients and complex multiple periorbital bone fracture in other 2 patients) underwent the reconstructive surgery by using three-dimensionally preformed titanium mesh plates. Eight cases underwent high density porous polyethylene implantation simultaneously. Evaluation of enophthalmos, eyeball movement, and orbit CT scan were taken pre- and post-operatively. RESULTS: The average enophthalmos was (3.9 ± 1.7) mm and the position of the affected eyeball was (3.1 ± 2.6) mm bellow the contralateral side preoperatively. Twelve patients suffered from eyeball movement restriction, including grade I in 4 cases, grade II in 7 cases and grade III in 2 cases. During the 3 to 6 months post operative follow-up, enophthalmos was completely corrected in 10 patients while the other 3 patients had residual 1.0 mm enophthalmos. The affected eyeballs were repositioned in 8 cases and 3 cases had residual 1 mm lower position and 2 cases with a 1 mm higher positioned eyeball. Eye movement was not restricted in 8 patients, whereas 3 patients had grade I movement restriction and 2 patients had grade II movement restriction. There were no rejection, infection and other complications during follow-up. CONCLUSIONS: Three-dimensionally preformed titanium mesh plates can be used to reconstruct posttraumatic complex orbital bone fractures in order to improve the orbital volume and to correct enophthalmos effectively.

[Clinical features and treatment of lateral orbital wall blow-in fracture].

OBJECTIVE: To analyze the clinical features of lateral orbital wall blow-in fracture and summarize the points of treatment. METHODS: A retrospective analysis of 12 patients with lateral orbital wall blow-in fracture treated in the Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine from January 2007 to January 2010 was investigated. Clinical records and results of follow-up were analyzed. RESULTS: Twelve cases of the lateral orbital wall blow-in fracture with the frontal process of the zygoma impacted into the orbit were confirmed. Globe rupture occurred in 1 case, 4 cases had traumatic optic neuropathy. 1 case suffered exophthalmos, 8 cases had enophthalmos. Diplopia was found in 5 cases and eyeball movement disturbance in 5 cases.3 cases had upper eyelid deformity, 1 case had ptosis, 3 cases had telecanthus accompanied with lacrimal ducts obstruction. 11 cases suffered orbital floor fracture, 9 cases had zygomatic arc fracture, 6 cases had orbital medial wall fracture, and 3 cases had naso-orbito-ethmoid fracture. Surgical treatment was performed by different combination of approaches according to the extents of injury; Osteotomy was performed in patients whose blow-in fracture was malformation. Orbital reconstructive surgery was performed in 11 patients and fractures were completely restored. CONCLUSIONS: The lateral orbital wall blow-in fracture could cause serious impairment to the ocular components, better outcomes could be achieved by timely and proper treatment with improving recognition of this type of fracture.

Cathelicidin LL37 Promotes Osteogenic Differentiation in vitro and Bone Regeneration in vivo.

Different types of biomaterials have been used to repair the defect of bony orbit. However, exposure and infections are still critical risks in clinical application. Biomaterials with characteristics of osteogenesis and antibiosis are needed for bone regeneration. In this study, we aimed to characterize the antimicrobial effects of cathelicidin-LL37 and to assess any impacts on osteogenic activity. Furthermore, we attempted to demonstrate the feasibility of LL37 as a potential strategy in the reconstruction of clinical bone defects. Human adipose-derived mesenchyme stem cells (hADSCs) were cultured with different concentrations of LL37 and the optimum concentration for osteogenesis was selected for further in vitro studies. We then evaluated the antibiotic properties of LL37 at the optimum osteogenic concentration. Finally, we estimated the efficiency of a PSeD/hADSCs/LL37 combined scaffold on reconstructing bone defects in the rat calvarial defect model. The osteogenic ability on hADSCs in vitro was shown to be dependent on the concentration of LL37 and reached a peak at 4 µg/ml. The optimum concentration of LL37 showed good antimicrobial properties against Escherichia coli and Staphylococcus anurans. The combination scaffold of PSeD/hADSCs/LL37 showed superior osteogenic properties compared to the PSeD/hADSCs, PSeD, and control groups scaffolds, indicating a strong bone reconstruction effect in the rat calvarial bone defect model. In Conclusion, LL37 was shown to promote osteogenic differentiation in vitro as well as antibacterial properties. The combination of PSeD/hADSCs/LL37 was advantageous in the rat calvarial defect reconstruction model, showing high potential in clinical bone regeneration.

Biomimetic nanofibrous hybrid hydrogel membranes with sustained growth factor release for guided bone regeneration.

Bone regeneration, a complex physiological process, remains a challenge due to the susceptibility to the environment and absence of osteogenic growth factors around the defect region. Although autologous bone grafting is regarded as the gold standard for bone defect treatment, guided bone regeneration membranes in combination with multiple functional growth factors show a striking regeneration effect. Here, a biomimetic nanofibrous hybrid hydrogel composed of bacterial cellulose membranes and alginate/CaCl2 for sustained growth factor delivery was developed. The antibacterial peptide beta-defensin 2 served as an antibacterial, osteogenic, and angiogenic growth factor and was loaded into the aforementioned hydrogel. The mechanical and physical properties of the biomimetic nanofibrous hybrid hydrogel were investigated. Then, the in vitro osteogenic and angiogenic differentiation was confirmed by alkaline phosphatase (ALP) activity, Alizarin Red S staining, qPCR, western blot analysis and tube formation assays. After implantation into a rat calvarial defect model for 12 weeks, nanofibrous hybrid hydrogel membranes could adhere to the defect surface and promote new bone and vessel regeneration.

Effect of Bifunctional ß Defensin 2-Modified Scaffold on Bone Defect Reconstruction.

Bone tissue engineering has emerged as an effective alternative treatment to the problem of bone defect. To repair a bone defect, antibiosis and osteogenesis are two essential aspects of the repair process. By searching the literature and performing exploratory experiments, we found that ß defensin 2 (BD2), with bifunctional properties of antibiosis and osteogenesis, was a feasible alternative for traditional growth factors. The antimicrobial ability of BD2 against Staphylococcus aureus and Escherichia coli was studied by the spread plate and live/dead staining methods (low effective concentration of 20 ng/mL). BD2 was also demonstrated to enhance osteogenesis, with higher messenger RNA (mRNA) and protein expression of the osteogenic markers collagen I (Col1), runt-related transcription factor 2 (Runx2), osteopontin (Opn), and osteocalcin (Ocn) in vitro (1.5-2.5-fold increase compared with the control group in the most effective concentration group), which was consistent with the alkaline phosphatase (ALP) and alizarin red S (ARS) staining results. We implanted poly(sebacoyl diglyceride) (PSeD) combined with BD2 and rat bone tissue-derived mesenchymal stem cells (rBMSCs) under the back skin of rats and found that the inflammatory response was significantly lower with this combination than with the PSeD/rBMSCs scaffold without BD2 and the pure PSeD group and was similar to the control group. Importantly, when assessed in a critical-sized in vivo rat 8 m diameter calvaria defect model, a scaffold we developed combining bifunctional BD2 with porous organic polymer displayed an osteogenic effect that was 160-200% greater than the control group. The in vivo study results revealed a significant osteogenic response and antimicrobial effect and were consistent with the in vitro results. In summary, BD2 displayed a great potential of simultaneously promoting bone regeneration and preventing infection and could provide a viable alternative to traditional growth factors applied in bone defect repair.

[Practice and exploration of orbital anatomy and orbital imaging courses in dental students].

PURPOSE: To improve the teaching effect of orbital anatomy course for students majoring in stomatology. METHODS: Based on a retrospective analysis of average score of orbital anatomy course for previous dental and medical students, and the problems existing in teaching effect, orbital anatomy and orbital imaging course were designed and carried out in dental students. The course combined imaging with orbital anatomy, and included clinical examples. Medical students were set as control. Examination was carried out after the end of the whole course, and the professional knowledge of orbital anatomy of two groups was compared. A self-designed questionnaire was designed to evaluate the teaching effect of orbital anatomy and orbital imaging courses for dental students and residents over 1 year after graduation. SPSS 22 software package was used for Statistical analysis. RESULTS: The previous average score of dental students was 7.50, and the average score of medical students was 8.67. There was significant difference between the two groups (P=0.004). The average score of dental students after offering the course of orbital anatomy and orbital imaging was 9.67, and the average score of medical students was 9.00. No significant difference was noticed between the two groups(P=0.184). Questionnaire survey showed that the after-class review time of dental students was 20 min, and that of medical students was 30 min. 74.7% of the dental students and 80% of the dental residents did not study orbital anatomy and imaging courses before. 87.4% of the dental students and 100% of dental residents considered that the orbital imaging course was helpful to master the anatomical characteristics of the orbit. 89.7% of the dental students and 100% of dental residents believed that orbital imaging course was helpful to their clinical work. CONCLUSIONS: Orbital anatomy and orbital imaging course were designed for dental students as supplementary teaching programme. It successfully inspired students' interest in learning, cultivated the students' overall and comprehensive thinking, narrowed students to master the knowledge of orbital anatomy, closed the gap of teaching effect between dental and clinical medicine, and laid the foundation to develop dental professional work in the future.

[Kinetics study on reaction of chlorine dioxide and thiocyanide in water].

OBJECTIVE: To study the kinetics rule of chlorine dioxide oxidize thiocyanide as the experimental objective. METHODS: Ultraviolet spectrophotometry was used to detect the concentration of chlorine dioxide and thocyanide which were changed with the time. According to initial rate method to determine the reaction order and rate equation, calculated Constant Rate, the activation energy, the half-life and other parameters. RESULTS: The reaction of chlorine dioxide oxidize thiocyanide was zero-order reaction both for chlorine and thiocyanide, order of overtall reaction was zero, too. At 293.15 K, k = 3.65 x 10(-6) mol/(L x s). E = 2.5 kJ/mol. CONCLUSION: Its activation energy was very little, reaction was fast. In general condition it could occour,while thiocyanide remained merely. It provided a new method for industry to deal with the waster contained thiocyanide.

[Repairing rabbit orbital defects with human BMP-2 gene modified bone marrow stromal cells and coral].

OBJECTIVE: To investigate the efficacy of tissue-engineered bone (human BMP-2 genetic modified BMSC combined with coral) in healing the segmental orbital defect in rabbits. METHODS: Rabbit BMSC were isolated and cultured in vitro, and cells of passage 2 were infected with adenovirus-mediated transfection of human BMP-2 gene (150 pfu/cell). After infection, the expression of BMP-2 was determined by RT-PCR and Western blot analysis, and cell proliferation and osteogenic differentiation were observed by flow cytometry, ALP and Alizarin red staining. A 12 mm bone defect in the infraorbital rim was induced by surgery in both orbits of 24 New Zealand white rabbits. The defects were repaired with modified tissue-engineered bone constructed with coral plus BMP-2 transfected BMSC (Group A, n = 12), constructed by coral plus non-transfected BMSC (Group B, n = 12) and grafts of coral alone (Group C, n = 12), with untreated group (Group D, n = 12) served as control. The osteogenesis of bone defect was monitored by gross observation, micro-CT measurement, histological and histomorphologic analysis at 4, 8, and 16 weeks after the implantation. RESULTS: After transfection, the BMP-2 expression was confirmed by RT-PCR and western blot, and the osteogenesis activity of BMSC could be obviously enhanced. The 12 mm segmental defect of rabbit orbit couldn't heal alone. Gross observation and micro-CT demonstrated well the bony-union in experimental group, with higher bone mineral density and more bone volume than other control groups (F = ll.46, F = 7180.97; P < 0.05). CONCLUSION: This study demonstrated that the rabbit orbital defect could be successfully repaired by tissue-engineered bone constructed with human BMP-2 gene modified BMSC and coral.

Delayed surgical treatment of orbital trapdoor fracture in paediatric patients.

BACKGROUND: Trapdoor fracture is a special type of orbital blowout fracture. Although early surgery is recommended, there still remain some patients delayed by various reasons. In this study, we analysed the clinical characteristics of delayed paediatric patients, especially those with different levels of ocular motility restriction before surgery. METHODS: Thirty patients (3 to 14 years old) who underwent delayed surgery for trapdoor fractures between January 2008 and September 2016 were enrolled. Their demographics, causes of injury and delay, clinical features, imaging data and follow-up information were collected. RESULTS: Muscular entrapment was found in 17 patients (group A) and soft-tissue entrapment in 13 patients (group B). 12 (7 in group A) presented with severe motility restriction and 18 (10 in group A) with mild restriction before surgery. 41.7% with severe restriction recovered after surgery, compared with 83.3% with mild restriction. Four (23.7%) in group A (all with severe restriction) and six (46.2%) in group B (half with severe restriction) presented with persistent diplopia. CONCLUSIONS: Long recovery time and a high percentage of persistent diplopia are the main problems of delayed trapdoor fracture in children. A prompt surgery within 48 hours is strongly recommended in patients with muscular entrapment even if an urgent treatment is hard to achieve. So are patients with soft-tissue entrapment and significant motility restriction. In the other patients without such indications, even though some recovery might be possible in the long term, a prompt surgery right after diagnosis is still preferable regardless of the entrapped contents.

A biodegradable functional water-responsive shape memory polymer for biomedical applications.

Shape memory polymers (SMPs) have exhibited great potential in biomedical applications. However, the typical triggers of shape recovery such as heat, UV light, and electricity may be harmful to humans. Accordingly, water-responsive SMPs have become significant, especially for in vivo applications, due to the intrinsic biocompatibility and ready availability of water. However, the reported water-responsive SMPs are limited and relatively complicated. Here, we design a new water-responsive SMP, poly(butanetetrol fumarate) (PBF); the properties of PBF could be modulated by curing. The cured PBF scaffolds exhibited high shape recovery and fixity rates (>95%). PBF showed good biodegradability, and it could support the attachment, viability and alkaline phosphatase activity of osteoblasts. Furthermore, PBF could be readily functionalized via pendant hydroxyl groups, which was demonstrated by the immobilization and controlled release of bone morphogenetic protein 2. We expect that PBF will be useful for various biomedical applications including water-responsive scaffolds, sensors or actuators.