Rational design of porous structure-based sodium alginate/chitosan sponges loaded with green synthesized hybrid antibacterial agents for infected wound healing.

An ideal wound dressing should have excellent antimicrobial properties and provide a suitable microenvironment for regenerating damaged skin tissue. In this study, we utilized sericin to biosynthesize silver nanoparticles in situ and introduced curcumin to obtain Sericin-AgNPs/Curcumin (Se-Ag/Cur) antimicrobial agent. The hybrid antimicrobial agent was then encapsulated in a physically double cross-linking 3D structure network (Sodium alginate-Chitosan, SC) to obtain the SC/Se-Ag/Cur composite sponge. The 3D structural networks were constructed through electrostatic interactions between sodium alginate and chitosan and ionic interactions between sodium alginate and calcium ions. The prepared composite sponges have excellent hygroscopicity (contact angle 51.3° ± 5.6°), moisture retention ability, porosity (67.32 % ± 3.37 %), and mechanical properties (>0.7 MPa) and exhibit good antibacterial ability against Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). In addition, in vivo experiments have shown that the composite sponge promotes epithelial regeneration and collagen deposition in wounds infected with S. aureus or P. aeruginosa. Tissue immunofluorescence staining analysis confirmed that the SC/Se-Ag/Cur complex sponge stimulated upregulated expression of CD31 to promote angiogenesis while downregulating TNF-α expression to reduce inflammation. These advantages make it an ideal candidate for infectious wound repair materials, providing an effective repair strategy for clinical skin trauma infections.

Case report: tracheobronchial diverticulum, a potential risk for diving?

Tracheobronchial diverticulum (TBD) is an asymptomatic, benign cystic lesion outside the lumen of the trachea and bronchus. This is the first report case of a SCUBA (self contained underwater breathing apparatus) diver diagnosed with TBD, which is a potential risk to diving. No literature or guideline is available so far on the diving fitness for patients with congenital or acquired TBD condition. A healthy 26-year-old male professional diver has records of SCUBA diving up to a depth of 40 meters sea water. He did not have any diving-related injuries or symptoms during his career and had no history of smoking, drinking, or other special illnesses except for a COVID-19 infection. A tracheal diverticulum was found accidentally by computed tomography (CT), but its communication with the trachea was not clear initially. Therefore, high-resolution CT and electronic bronchoscopy were done to clarify the situation of the diverticulum and identify the diving risk. High-resolution CT showed a possible opening in the diverticulum, but this was not seen under electronic bronchoscopy. Although a potential opening was shown in high-resolution CT, the lack of visual bronchoscopic evidence made it likely to be a dead cavity. As there is a higher theoretical risk of barotrauma during decompression, leading to pneumomediastinum, hemorrhage, or arterial gas embolism, the current clinical consensus is that air-containing tissue should be regarded as a relative contraindication for diving. Overall, it is recommended that the diver should dive carefully and avoid ascending too rapidly.

Effect of 1,25-Dihydroxyvitamin D3 on Stem Cells from Human Apical Papilla: Adhesion, Spreading, Proliferation, and Osteogenic Differentiation.

Currently, it still remains a difficult problem to treat apical insufficiency of young permanent teeth resulted from pulp necrosis or periapical periodontitis. Previous studies have demonstrated that the treatment of revascularization using stem cells from apical papilla (SCAPs) results in increased root length and thickness of traumatized immature teeth and necrotic pulp. In this study, we investigated the role of 1,25-dihydroxyvitamin D3 in regulating the adhesion, spreading, proliferation, and osteogenic differentiation of SCAP, laying the foundation for subsequent clinical drug development. The immature tooth samples were collected in clinical treatment. SCAPs with stable passage ability were isolated and cultured. The multidifferentiation potential was determined by directed induction culture, while the stem cell characteristics were identified by flow cytometry. There were three groups: group A-SCAPs general culture group; group B-SCAPs osteogenesis induction culture group; and group C-SCAPs osteogenesis induction culture+1,25-dihydroxyvitamin D3 group, and the groups were compared statistically. The proliferation of SCAPs in each groups was detected through CCK-8 assay. RT-qPCR was used to detect the transcription levels of Runx2, ALP, Col I, and OCN of SCAPs in each groups. Results exhibited that the isolated SCAPs had multidifferentiation potential and stem cell characteristics. After 24 h culturing, cells in group C spread better than those in groups A and B. The proliferation activity of SCAPs factored by CCK-8 ranked as group C > group B > group A, while the transcription levels of Runx2, ALP, Col I, and OCN leveled as group C > group B > group A. These results suggested that 1,25-dihydroxyvitamin D3 can significantly promote the adhesion, spreading, and proliferation of SACPs and improve the osteogenic differentiation of SCAPs by means of regulating upward the transcription level of osteogenic differentiation marker.

Collective influence of substrate chemistry with physiological fluid shear stress on human umbilical vein endothelial cells.

In the treatment of cardiovascular diseases, vascular scaffold materials play an extremely important role. The appropriate substrate chemistries and 15 dynes/cm2 physiological fluid shear stress (FSS) are both required to ensure normal physiological activity of human umbilical vein endothelial cells (HUVECs). The present study reported the collective influence of substrate chemistries and FSS on HUVECs in the sense of its biological functions. The CH3 , NH2 , and OH functional groups were adopted to offer a variety of substrate chemistries on glass slides by the technology of self-assembled monolayers, whereas FSS was generated by a parallel-plate fluid flow system. Substrate chemistries on its own by no means had noticeable effects on eNOS, ATP, NO, and PGI2 expressions, while FSS stimuli enhanced their production. While substrate chemistries, as well as FSS, were both exerted, the releases of ATP, NO, and PGI2 were dependent on substrate chemistries. Study of F-actin organization and focal adhesions (FAs) formation of HUVECs before FSS exposure proves that F-action organization and FAs formation followed similar chemistry-dependence. Hereby proposed a feasible mechanism, that is, the F-actin organization and FAs formation of HUVECs are controlled by substrate chemistries, further advancing the modulation of FSS-triggered responses of HUVECs.

[Research progress on controlled release of various growth factors in bone regeneration].

OBJECTIVE: To summarize the research progress of controlled release of angiogenic factors and osteogenic factors in bone tissue engineering. METHODS: The domestic and abroad literature on the controlled release structure of growth factors during bone regeneration in recent years was extensively reviewed and summarized. RESULTS: The sustained-release structure includes direct binding, microsphere-three-dimensional scaffold structure, core-shell structure, layer self-assembly, hydrogel, and gene carrier. A sustained-release system composed of different sustained-release structures combined with different growth factors can promote bone regeneration and angiogenesis. CONCLUSION: Due to its controllability and persistence, the growth factor sustained-release system has become a research hotspot in bone tissue engineering and has broad application prospects.

Functional Reconstruction of Mandibular Segment Defects With Individual Preformed Reconstruction Plate and Computed Tomographic Angiography-Aided Iliac Crest Flap.

PURPOSE: With the development of imaging technology and computer-assisted surgery in oral and maxillofacial surgery, digital technology is widely used in vascularized bone flap grafts for mandibular reconstruction. The aim of this study was to use digital technology throughout the treatment process to show that digital techniques can provide a reliable and accurate match between the mandible and the iliac crest flap to achieve functional reconstruction of mandibular segment defects. MATERIALS AND METHODS: Twenty patients underwent 3-dimensional (3D) computed tomography (CT), mirroring technology, 3D model prototyping, and CT angiography (CTA) for treatment planning. Individual preformed reconstruction plates were fabricated and iliac crest flaps were designed preoperatively. After complete resection of the mandibular lesion, the iliac crest flap was shaped to reconstruct the mandibular defects. RESULTS: During follow-up (range, 12 to 36 months), the facial shape, facial symmetry, and mouth opening of all patients recovered well. The 3D CT reconstruction also was evaluated for height, width, length, and bone healing of the iliac crest flap. Postoperative examination showed ideal bone union between the iliac crest flap and the mandible at 6 months. Nine patients received implant-supported fixed dentures to restore dentition. After follow-up, all patients were satisfied with their facial esthetics and function. The new mandible provided a suitable 3D position for implant-supported fixed partial dentures. CONCLUSION: Use of digital techniques throughout the course of treatment improves the predictability and convenience of functional mandibular reconstruction. Individual preformed reconstruction plates and CTA effectively guaranteed the accuracy of iliac flap preparation.

[Application of individual prefabricated reconstructive titanic plate combined with vascularized iliac bone-muscular flap for reconstruction of mandibular defects]

Objective To investigate the clinical effect of individual prefabricated reconstructive titanic plate combined with vascularized iliac bone-muscular flap for reconstruction of mandibular defects. Methods: From Aug.2010 to Dec.2014,12 cases with mandibular tumor received preoperative maxillofacial CT scans and 3-dimensional reconstruction. Based on the CT results, mirror imaging technology was used to simulate the reconstruction of the defect at affected side. The individual reconstructive titanium plate was prefabricated on the model. The iliac bone-muscular flap was designed according to the defect shape and size, combined with reconstructive plate. All patients underwent CT scan and oral curved surface tomography postoperatively. The maxillofacial function and appearance were also evaluated. Results: According to the CT scan and curved surface tomography, the 12 iliac bone-muscular flaps survived completely with good bone union and good condyle position. Both the functional and cosmetic results were satisfactory. There was no complication on the donor sites. Conclusions: Individual prefabricated reconstructive titanic plate combined with vascularized iliac bone-muscular flap provides an precise method for reconstruction of mandibular defects. The cosmetic and functional results could be expected.

[Application of anterolateral thigh myocutaneous flap using computed tomography angiography for mouth-floor reconstruction after resection of middle-late stage carcinoma of mouth floor].

OBJECTIVE: The aim of this study was to investigate the value of free anterolateral thigh myocutaneous flap (ALTMF) and computed tomography angiography (CTA) for the reconstruction of mouth-floor defects after the resection of middle-late stage carcinoma of the mouth floor. METHODS: Sixteen cases of middle-late stage carcinomas of the mouth floor underwent radical resection, and mouth-floor and tongue defects were reconstructed with ALTMF. CTA was applied to plan the lateral circumflex femoral artery (LCFA) and its perforating vessel, which was verified during the operation. RESULTS: The position of the perforating vessel in the operation was fully consistent with that designed by the preoperative CTA. All 16 flaps completely survived. The appearance and function of all cases were both satisfactory. All donor sites were primarily closed and healed without functional morbidity. During the follow-up period of 6-36 months, 15 cases survived with acceptable aesthetic and functional results in mouth floor and tongue reconstruction, except for 1 case (T4N2M0) that died of metastasis carcinoma 10 months after operation. CONCLUSION: CTA can accurately locate the LCFA and artery perforator. Preoperative perforator planning using CTA in ALTMF transplantation is a reliable and useful method thatresults in safe operation with optimal outcome. The ALTMF is an ideal choice for the reconstruction of soft tissue defects after the resection of middle-late staie carcinoma of the mouth floor

[EFFECT OF TRITON X-100 ON LIPOSOME MEDIATED BONE MORPHOGENETIC PROTEIN 2 BY TRANSFECTION OF RAT BONE MARROW MESENCHYMAL STEM CELLS].

OBJECTIVE: To study the effect of Triton X-100 promoting liposome-mediated bone morphogenetic protein 2 (BMP-2) gene transfection of rat bone marrow mesenchymal stem cells (BMSCs). METHODS: BMSCs were separated and cultured from the femur and tibia of healthy Wistar rats (8-week-old, male). The 3rd passage BMSCs identified by detecting the surface antigen were used to transfect. The optimum concentration of Triton X-100 for liposome mediated gene transfection was determined with ELISA meter by the way of MTT. In optimum concentration of Triton X-100, liposome mediated BMP-2 gene was transfected to BMSCs. The experiment was divided into 3 groups according to types of trasfection agents: BMSCs were transfected with Triton X-100+liposome+BMP-2 (experimental group), with liposome+ BMP-2 (conventional transfection group), and untransfected BMSCs served as blank control group. After 48 hours of transfecting, the green fluorescent protein (GFP) in cells was detected through inverted fluorescence microscope. After 72 hours of transfection, real-time fluorescence quantitative PCR was applied to measure the mRNA expression of BMP-2. RESULTS: 0.01% Triton X-100 was determined to be the optimum concentration for not only making the BMSCs maintain vitality, but also achieving a certain effect on BMSCs. After trasfecting for 48 hours, GFP was observed through inverted fluorescence microscope in the experimental group and conventional transfection group, but was not observed in the blank control group. After trasfecting for 72 hours, the relative BMP-2 mRNA expression level was 5.94 ± 0.12 in the experimental group, and was 4.99 ± 0.08 in the conventional transfection group, showing significant difference (t = 360.28, P = 0.02). The transfection efficiency was increased by 19% in the experimental group. CONCLUSION: 0.010% Triton X-100 can promote the liposome mediated BMP-2 gene transfection of rat BMSUs, and can improve the transfection efficiency.

[Vascularized composite flap with iliac crest and internal oblique muscle of abdomen for half mandibular reconstruction].

OBJECTIVE: To investigate the effect of vascularized composite flap with iliac crest and nternal oblique muscle of abdomen for half mandibular reconstruction. METHODS: From July 2009 to Sept. 2013, 14 cases with half mandibular defect after tumor resection were treated with composite flap of iliac crest and internal oblique muscle of abdomen pedicled by deep circumflex iliac vessels. During operation, one group performed tumor resection and got the recipient area vessels ready for anastomosis. The other group performed harvesting of composite flap. Then the flap was trimmed and fixed to construct the defect with vessel anastomosis. RESULTS: All the 14 composite flaps survived with local infection only in 1 case. The size of harvested iliac crest ranged from 6 cm x 3 cm to 9 cm x 3 cm. The size of harvested internal oblique muscle of abdomen ranged from 5 cm x 4 cm to 7 cm x 5 cm. The patients were followed up for 6 months to 26 months (mean, 13 months) with satisfactory results and no complication. Mandibular panoramic radiographs showed new bone formation and good union. CONCLUSIONS: Vascularized composite flap with iliac crest and internal oblique muscle of abdomen has the advantages of abundant bone volume, as well as soft tissue reconstruction in one stage. The reconstructed mandible can attain normal function and appearance.

[The effect of osteogenic inducer on healing of tooth extraction sockets].

OBJECTIVE: To study the effect of osteogenic inducer (dexamethasone, beta-sodium glycerophosphate and Vitamin C) carried by gelatin sponge on healing and remodeling of tooth extraction sockets. METHODS: Fifty rabbits were selected. After extracting the first premolars of bilateral maxillary, the right side tooth extraction sockets were filled with gelatin sponge containing osteogenic inducer as experimental side, tooth extraction sockets on left side were filled with gelatin sponge as control. Every ten rabbits were executed at the end of 1, 2, 4, 8, 12 weeks after tooth extraction. Bone density was measured through digital X-ray images. The specimens were examined by histology. The absorption height of alveolar bone at 12 weeks was measured. RESULTS: X-ray measurement showed that the bone density of experimental side was higher than that of control side at 2, 4, 8, 12 weeks, the difference had statistical significance (P<0.01). The histology examination showed that new bone formation in tooth extraction sockets of experimental side was earlier than that in control side. The absorptional height of alveolar bone had significant difference between experimental side and control side (P<0.01), of which experimental side was less. CONCLUSION: Filling the osteogenic inducer in tooth extraction sockets can promote the healing and new bone formation and prevent from alveolar bone absorption.

[Application of anterolateral thigh myocutaneous flap in the reconstruction of tongue and mouth floor defect after tongue carcinoma].

OBJECTIVE: To investigate the application of free anterolateral thigh myocutaneous flap in the reconstruction of tongue and mouth floor defect after radical resection of tongue carcinoma. METHODS: From June 2006 to April 2009, 14 cases with tongue carcinoma underwent radical resection, leaving tongue and mouth floor defects which were reconstructed by anterolateral thigh myocutaneous flaps at the same stage. These 14 cases included tongue carcinoma at lingual margin (n=9), at ventral tongue (n=3) and at mouth floor (n=2). The flap size ranged from 7 cm x 9 cm to 5 cm x 7 cm. RESULTS: All the 14 flaps survived completely with primary healing. There was no functional morbidity in the lower extremities. The patients were followed up for 12-26 months with satisfied esthetic and functional results in reconstructed tongue. Only one case (T4 N1 M0) died of metastasis carcinoma 14 months after operation. No local recurrence happened. CONCLUSIONS: The anterolateral thigh myocutaneous flap has abundant tissue volume to reconstruct the tongue and mouth floor defect, while leaving less morbidity at donor site. Both satisfied esthetic and functional results can be achieved.

[Analysis of the complications following mandibular distraction using internal distractors].

OBJECTIVE: To investigate the causes and the prophylactic for the complications following mandibular distraction osteogenesis using internal distractors. METHODS: From 1997 to 2004, a total of 46 patients (61 sides) suffering from malformations or defects of mandible who underwent mandibular distraction osteogenesis were analyzed. The diseases included hemifacial microsomia in 27 cases, congenital or acquired mandibular hypoplasia and micrognathia bilateral in 8 cases and unilateral in 4 cases, electronical injury or postoperative mandibular defects in 3 cases, Treacher Collins syndrome in 2 cases, obstructive sleep apnea syndrome in 2 cases. RESULTS: Of them, 9 patients had postoperative complications, which included 3 patients had complications associated with distractors, local infection occurred in 2 cases, apertognathia of anterior teeth in 2 case, 2 patients had sinus of the skin of the lower lip. 9 patients had been aggressivly managed and obtained satisfactory results. CONCLUSIONS: The pivotal points to reduce complications are to understand the mechanism of mandibular distraction osteogenesis completely, and to be familiar with the anatomy of mandible and adjacent tissues. It is necessary to treat with it preoperatively and postoperatively.

[Surgical management of craniomaxillofacial fibrous dysplasia].

OBJECTIVE: To explore the method to obtain good aesthetic and functional results in surgical management of craniomaxillofacial fibrous dysplasia and correct the grotesque deformity. METHODS: According to the type of the lesions, different excision and reconstruction methods were used. RESULTS: 19 cases (4 monostotic cases and 15 polyostotic cases) were surgically treated. The period of follow-up range from 9 months to 5 years, all patients obtained satisfactory aesthetic and functional results. No relapse happened during follow up. CONCLUSIONS: Based on modern craniomaxillofacial techniques and computer aided design, extensive radical excision and craniomaxillofacial skeleton reconstruction could be safely accomplished, and the better results were obtained, both aestheticly and functionally.

[Fabrication of 3-dimensional skull model with rapid prototyping technique and its primary application in repairing one case of cranio-maxillo-facial trauma].

OBJECTIVE: To investigate the methods of establishing 3-dimensional skull model using electron beam CT (EBCT) data rapid prototyping technique, and to discuss its application in repairing cranio-maxillo-facial trauma. METHODS: The data were obtained by EBCT continuous volumetric scanning with 1.0 mm slice at thickness. The data were transferred to work-station for 3-dimensional surface reconstruction by computer-aided design software and the images were saved as STL file. The data can be used to control a laser rapid-prototyping device (AFS-320QZ) to construct geometric model. The material for the model construction is a kind of laser-sensitive resin power, which will become a mass when scanned by laser beam. The design and simulation of operation can be done on the model. The image data were transferred to the device slice by slice. Thus a geometric model is constructed according to the image data by repeating this process. Preoperative analysis, surgery simulation and implant of bone defect could be done on this computer-aided manufactured 3D model. One case of cranio-maxillo-facial bone defect resulting from trauma was reconstructed with this method. The EBCT scanning showed that the defect area was 4 cm x 6 cm. The nose was flat and deviated to left. RESULTS: The 3-dimensional skull was reconstructed with EBCT data and rapid prototyping technique. The model can display the structure of 3-dimensional anatomy and their relationship. The prefabricated implant by 3-dimensional model was well-matched with defect. The deformities of flat and deviated nose were corrected. The clinical result was satisfactory after a follow-up of 17 months. CONCLUSION: The 3-dimensional model of skull can replicate the prototype of disease and play an important role in the diagnosis and simulation of operation for repairing cranio-maxillo-facial trauma.

[Complications of scalp coronal incision: analysis, prevention, and treatment].

OBJECTIVE: The aim of this study was to analyze the complications of coronal incision and investigate the methods of prevention. METHODS: The retrospective analysis was based on 149 cases, who have had operations since 1997 for congenital craniofacial malformation, second deformation of craniomaxillofacial trauma, maxillofacial tumor or cosmetic purposes. RESULTS: Of them, there were injury of unilateral frontal branch of the facial nerve in 3 cases, subcutaneous hematoma in 9 cases, alopecia in 12 cases, incision scar in 14 cases, obvious strip scar in 2 cases, pains, numbness and paraesthesia in 23 cases, ptosis of facial soft tissue in 8 cases and infection in 4 cases. CONCLUSIONS: The coronal incision has the merits of distinct exposure, hidden incision scar, but its complications can not be neglected. During the operation, care should be taken to anatomical layers, protecting the blood vessel and nerve bundle in order to reduce complications.

[Skeleton reconstruction of oblique facial clefts using mandibular outer table].

OBJECTIVE: This paper presents a new method of skeleton reconstruction for oblique facial clefts using autogenous bone of the mandibular outer table. METHODS: In the operation, the mandibular outer table was harvested through the intraoral approach. Assisted with internal rigid fixation technique, the mandibular outer table was used to reconstruct the naso-orbital framework as inlay or onlay bone graft. RESULTS: From 1993 to 2001, seven cases of oblique facial clefts were repaired with mandibular outer table bone graft. Postoperative follow-up for 6 months to 3 years demonstrated that the grafted bone healed well with the adjacent bones. No obvious bone resorption was observed. The facial appearance was improved greatly. CONCLUSIONS: The mandibular outer table, with similar bone density to the calvarium, is easy to harvest without donor site scar. The method is quite ideal for skeleton reconstruction of oblique facial clefts.

[Applications of autogenous outer table of the calvarial and mandibular bone in posttraumatic deformities of the nose].

OBJECTIVE: To study the applications of bone grafts from the cranium or mandible in the repair of posttraumatic deformities of the nose. METHODS: From 1997 to 2002, a total of 44 patients, who presented with secondary nose deformity as well as facial fractures, were reconstructed by autogeneous outer table grafts of the calvarial or mandibular bone after facial skeleton reposition. In this series, 32 cases used the calvarial bone, 12 cases used the mandible bone, which was harvested through a coronal incision and an oral approach respectively. RESULTS: The surgical incisions healed primarily in all patients with minimal scar. The facial appearance was greatly improved. No implant infection, extrusion and shift were observed in the postoperative follow-up of 6 months to 2 years. There was not obvious bone resorption, nor donor site morbidity. CONCLUSION: Autogeneous calvarial and mandibular bone was an ideal material of bone graft in reconstruction of severe posttraumatic deformities of the nose. Compared with other autogeneous and alloplastic materials, the outer table of the calvarial and mandibular bone produced less morbidity of the donor site, invisible scar, no rejection and less resorption.

[Chin augmentation with bone transplantation from the mandible].

OBJECTIVE: To explore a new method for mentoplasty. METHODS: The bilateral prominent mandibular angle or outer lamina was resected through the intraoral approach. The resected bone fragments were shaped and rigid fixed to the chin with miniplates and screws. RESULTS: A total of 30 patients (28 females, 2 males) accepted chin augmentation with this method. The mandibular angle bone was used in 20 cases and the mandibular outer lamina was used in 10 cases. The operative results were satisfactory, and the patient's facial contour was improved substantially. CONCLUSION: No rejection reaction was found after this procedure. Chin augmentation with autogenous mandibular bone is an ideal method for genioplasty.

[Individual prefabricated titanium implant for the reconstruction of the skull bone defect].

OBJECTIVE: This paper presents a new method of individual prefabricated titanium implant for the reconstruction of the skull bone defect. METHOD: A computer-based 3D model of the cranial bone defect is created from helical CT-data and serves as the basis for the computer aided design and manufacturing (CAD/CAM) of the individual prefabricated titanium implant for the cranial bone defect reconstruction. RESULT: Since 2001, a total of nine patients suffering from the cranial bone defect have been operated on by this method with satisfied result. The fallow-up is 3 to 12 months. CONCLUSION: These individual prefabricated titanium implants have won a high precision, a good biomechanics and a excellent biocompatibility. It is a quite ideal and very simple method with much less complication for the surgical treatment of the cranial bone defect.