Tantalum-incorporated hydroxyapatite coating on titanium implants: its mechanical and in vitro osteogenic properties.

OBJECTIVE: The fabrication of bioactive coatings on metallic implants to enhance osseointegration has become a topic of general interest in orthopedics and dentistry. Hydroxyapatite (HA) coating has been shown to induce bone formation and promote bone-implant integration. Unfortunately, poor mechanical performance has hindered this from becoming a favorable coating material. The majority of present studies have focused in incorporating different elements into HA coatings to improve mechanical properties. In recent years, tantalum (Ta) has received increasing attention due to its excellent biocompatibility and corrosion resistance. The aim of on the present study was to investigate the fabrication and biological performance of Ta-incorporated HA coatings. METHODS: Ta-incorporated HA coatings were fabricated using the plasma spray technique on a titanium substrate, and the surface characteristics and mechanical properties were examined. In addition, the effects of Ta-incorporated HA coatings on the biological behavior of mesenchymal stem cells (BMSCs) were investigated. RESULTS: Ta-incorporated HA coatings with microporous structure had higher roughness and wettability. In addition, the bonding strength of Ta/HA coatings with the substrate was substantially superior to HA coatings. Furthermore, Ta-incorporated HA coatings not only facilitated initial cell adhesion and faster proliferation, but also promoted the osteogenic differentiation of BMSCs. CONCLUSION: These results indicate that the incorporation of Ta could improve mechanical performance and increase the osteogenic activity of HA coatings. The Ta-incorporated HA coating fabricated by plasma spraying is expected to be a promising bio-coating material for metallic implants.

The effects of hyperglycemia on the biological behavior of human gingival fibroblasts on a titanium surface.

BACKGROUND: It is well known that diabetes mellitus is one of the high-risk factors for periodontitis and also for the failure of implant restorations. Usually, the success of an implant restoration depends on both the good osseointegration and the stable soft tissue interface on the implant neck. A good gingival interface of the implant neck is the barrier that enables implant to resist oral microorganisms and the site of initiation of peri-implantitis. This study sought to investigate the effects of hyperglycemia on the attachment and proliferation of human gingival fibroblasts (HGFs) on pure titanium surfaces. METHODS: HGFs were cultured in cell culture mediums with different glucose concentrations (i.e., 5.5, 8. 8, 10, and 15 mmol/L) for 7 d and seeded on pure titanium surfaces. The cells that were seeded on the titanium surfaces had been cultured in cell culture mediums with different glucose concentrations for 3 and 7 d. The attached HGFs on the titanium surfaces were counted for all groups using a blood cell counting plate, and the results were statistically analyzed. The morphologies of the attached HGFs on the titanium surfaces were observed for all the groups using a scanning electronic microscope. RESULTS: As the glucose concentrations increased, the number of attached HGFs on the titanium surfaces decreased. The numbers of attached cells in Groups A and B 7 d after being seeded on the titanium surfaces were more than those 3 d after being seeded (P<0.05). The numbers of attached cells in Groups C and D 3 d after being seeded on the titanium were more than those 7 d after being seeded (P<0.05). The scanning electronic microscope showed that the attached cells in Groups A and B proliferated well, and most cells grew one on top of another. Conversely, the attached cells in Groups C and D proliferated sparsely and the cell morphologies were not good. CONCLUSIONS: The attachment and proliferation of HGFs on pure titanium surfaces were inhibited by increases in glucose concentrations, and the inhibition was further enhanced by the passage of time.

Clinical application and accuracy analysis of 3D printing guide plate based on polylactic acid in mandible reconstruction with fibula flap.

BACKGROUND: Due to the special anatomy morphology and physiological function of the mandible, it has always become a challenge to accurately reconstruct the mandibular defect in maxillofacial surgery. Digital three dimensions (3D) printing surgical guide, as the effective method for individual and accurate surgery, is a hotspot of clinical research at present. In this study, 3D printing PLA surgical guide plate was applied to reconstruct the mandibular defect with fibula flap, its clinical effect and accuracy were evaluated, which aimed to improve the accurate reconstruction of mandibular defects. METHODS: After sterilization, the dimension deformation of the PLA standard specimen were measured. Eighteen patients diagnose with mandibular tumor were collected as observation objects. Then partial mandible resection and simultaneous mandible reconstruction with fibula graft were implemented according to the computer-aided design plan. The clinical effects of 3D printing PLA guide plates application were evaluated by facial contours, occlusal stability and chewing function. Through registering the postoperative computed images reconstruction with preoperative designed shape, the reconstruction accuracy was evaluated by detecting the maximum difference including the distance between lateral convex point of the condyles, the distance between medial convex point of the condyles and the horizontal contained angle between long axis of the condyles. RESULTS: After high temperature steam sterilization, the curvature of the PLA specimen with 100% filling rate and 4.8 mm thickness were the smallest and their dimension deformation had no statistical significance (P>0.05). The minimally deformed 3D printing PLA guide plate were smoothly placed in the right place during the operation. After surgery, the face was symmetrical, the occlusal relationship was restored well and no deviation of the mandibular movement were found. The spiral computed tomography (SCT) scanning showed that the distance between lateral/medial convex points of the condyle and the horizontal contained angle were 128.34±8.68 mm, 88.69±6.75 mm and 145.87°±12.01°. Compared with preoperative design, the maximum deviation of the actual postoperative registration was 1.67±0.63, and the difference was not statistically significant (P>0.05). CONCLUSIONS: The application of 3D printing PLA guide plate in the segmental section and reconstruction of the mandible can effectively simplify the operation, and better reconstruct the continuity of the mandible. The surgical accuracy can fully meet clinical needs with relatively low prices.

Identifying Factors Associated with Head Impact Kinematics and Brain Strain in High School American Football via Instrumented Mouthguards.

Repeated head impact exposure and concussions are common in American football. Identifying the factors associated with high magnitude impacts aids in informing sport policy changes, improvements to protective equipment, and better understanding of the brain's response to mechanical loading. Recently, the Stanford Instrumented Mouthguard (MiG2.0) has seen several improvements in its accuracy in measuring head kinematics and its ability to correctly differentiate between true head impact events and false positives. Using this device, the present study sought to identify factors (e.g., player position, helmet model, direction of head acceleration, etc.) that are associated with head impact kinematics and brain strain in high school American football athletes. 116 athletes were monitored over a total of 888 athlete exposures. 602 total impacts were captured and verified by the MiG2.0's validated impact detection algorithm. Peak values of linear acceleration, angular velocity, and angular acceleration were obtained from the mouthguard kinematics. The kinematics were also entered into a previously developed finite element model of the human brain to compute the 95th percentile maximum principal strain. Overall, impacts were (mean ± SD) 34.0 ± 24.3 g for peak linear acceleration, 22.2 ± 15.4 rad/s for peak angular velocity, 2979.4 ± 3030.4 rad/s2 for peak angular acceleration, and 0.262 ± 0.241 for 95th percentile maximum principal strain. Statistical analyses revealed that impacts resulting in Forward head accelerations had higher magnitudes of peak kinematics and brain strain than Lateral or Rearward impacts and that athletes in skill positions sustained impacts of greater magnitude than athletes in line positions. 95th percentile maximum principal strain was significantly lower in the observed cohort of high school football athletes than previous reports of collegiate football athletes. No differences in impact magnitude were observed in athletes with or without previous concussion history, in athletes wearing different helmet models, or in junior varsity or varsity athletes. This study presents novel information on head acceleration events and their resulting brain strain in high school American football from our advanced, validated method of measuring head kinematics via instrumented mouthguard technology.

[Morphological change analysis based on cone beam CT of the upper airway for obstructive sleep apnea syndrome patients treated with oral appliance in skeletal class ⠡ malocclusion with different vertical patterns].

OBJECTIVE: To analyze the morphological changes in the upper airway of obstructive sleep apnea syndrome (OSAS) patients treated with oral appliance in skeletal class Ⅱ malocclusion with different vertical features by using cone beam CT (CBCT). METHODS: Thirty-six patients diagnosed with OSAS by polysomnography and daytime sleepiness scale and skeletal class Ⅱ malocclusion were treated with oral appliance for 4 months. The changes based on CBCT in the morphology of glossopharyngeal and palatopharyngeal before and after treatment in OSAS patients with different vertical features were compared. RESULTS: After treatment with oral appliance, the glossopharyngeal and palatopharyngeal morphologies of patients with mild OSAS showed significant changes. After treatment with oral appliance, the glossopharyngeal morphology of all patients showed significant changes (P<0.05). The palatopharyngeal morphology of patients in the lower and average groups also exhibited significant changes (P<0.05). Sagittal changes in the glossopharyngeal measurements of high-angle patients demonstrated significant difference, whereas the other measured values showed no significant difference. CONCLUSIONS: The morphological changes in the upper airway were significant in OSAS patients with lower and average vertical patterns when treated with oral appliance, but the changes in high vertical patterns were not significant.

[Biomechanical strength of bone cement impregnated with diphosphonate].

OBJECTIVE: To investigate the biomechanical strength of diphosphonate impregnated bone cement (DIBC). METHODS: DIBC specimens were manufactured and randomly assigned to the control groups and the DIBC groups. According to the corresponding ASTM/ISO standards, the static biomechanical strength and the fatigue limit were tested systematically. The particle size distribution of diphosphonate powder was analyzed with the laser light scattering method. The fatigue test results, given as number of cycles-to-failure, were analyzed using the linearized format of the two-parameter Weibull function. RESULTS: With the drug load increased, there was a slight increase in static biomechanical strength and a moderate decrease in fatigue limit, both with statistical significance. When immersed in PBS before the tests, the DIBC specimens presented an overall significant decrease of static biomechanical strength and fatigue limit. The profile of drug particle sizes presented a normal distribution. CONCLUSIONS: The adopted diphosphonate is a much homogeneous powder which contains particles with a low range of sizes. The impregnation of diphosphonate exerted no or less negative effect on the biomechanical strength of the acrylic bone cement, of which the static strength of DIBC is maintained high above the ASTM/ISO standards.

Profiling drug membrane permeability and activity via biopartitioning chromatography.

Drug in vivo pharmacokinetic performances in nature consist of sequential membrane transporting processes and are based on the entry into and exit of drugs from cell, even for metabolism process requiring parent drugs delivered into and metabolites effluxed from the metabolizing cells. Efficient and reliable high throughput screen of membrane permeability properties as early as possible in drug discovery and development program is accordingly desirable. Biopartitioning chromatography (BPC) introduces biomembrane-mimetic structures (such as liposome, phospholipid monolayer, micelle, microemulsion, vesicle and bicelle, etc) into chromatographic system, i.e. liquid system or capillary electrophoresis, and thereby emulates drug-membrane interactions difficult to study in the liquid state by well reproducible, rapid, sensitive and adequately designed chromatographic technique. And recently BPC has been becoming a high-throughput screening platform for drug membrane permeability and biological activity. The theoretical basis, classification and application of BPC were summarized based on the latest advances and our recent works. The development potential and perspectives of this field were also discussed.

[Study on the sorption and isolation of shikimic acid by 717 anion exchange resin].

OBJECTIVE: To establish a convenient, practical and environmental method for extracting and isolating shikimic acid. METHODS: The content of shikimic acid was measured by RP-ion-pair HPLC, the effects of different pH, temperature, sample concentration and eluate concentration on 717 anion exchange resin were studied. RESULTS: The yield of shikimic acid was 96.52% on the condition of 22 degrees C, pH > 6.5, 7.5 mg /ml sample concentration and 0.03 mol/L HCl eluting. CONCLUSION: This method is feasible and suitable for the extraction and isolation of shikimic acid.

[Surface modification of biodegradable polymer/TCP scaffolds and related research].

Under laboratory condition, the compound materials of Poly (DL-lactic-co-glycolic acid)/Tricalcium phosphate [PLGA/TCP(L), with component ratio of 7:3] were fabricated by combining the thermally induced phase separation (TIPS) with solvent-casting particulate-leaching (SCPL) approach. On the other hand, rapid prototyping (RP) technique manufactured PLGA/TCP scaffolds [PLGA/TCP(RP)] were obtained. These two kinds of carriers were coated with collagen type I (Col I). The extracted bovine bone morphogenetic protein (bBMP) was loaded into carriers to establish biomimetic synthetic bones. PLGA/TCP(L) scaffolds, demineralized bone matrices (DBM) of bovine cancellous bone, PLGA/TCP(L) scaffolds, biomimetic synthetic bones and OsteoSet bone graft substitutes were investigated. Scanning electron microscopy revealed that the microarchitecture of PLGA/TCP(RP) scaffolds was much better than that of PLGA/TCP(L) scaffolds. The diameter of macropore of PLGA/TCP(RP) scaffold was 350 microm. The porosities of PLGA/ TCP(L) scaffolds, DBM, PLGA/TCP(RP) scaffolds and OsteoSet bone graft substitutes were 21.5%, 70.4%, 58.6% and 0%, respectively (P<0.01). Modification of PLGA/TCP scaffolds with collagen type I [PLGA/TCP(L)-Col I and PLGA/TCP(RP)-Col I] essentially increased the affinity of the carriers to bBMP. Among these synthetic materials, PLGA/TCP(RP)-Col I-bBMP composite is promising as a novel bone graft substitute due to its advanced fabrication technique, good tri-dimensional microarchitecture and ideal components.

[Effect of diode laser in the treatment of 78 patients with sinus chronic apical abscess].

PURPOSE: To explore the effect of diode laser in the treatment of sinus chronic apical abscess. METHODS: A total of 78 patients with sinus chronic apical abscess were randomly divided into experimental group and control group, 39 cases in each group. Patients in the control group were treated with conventional root canal preparation and calcium hydroxide sealant. After conventional root canal preparation, the canals in the experimental group were disinfected with diode laser and then calcium hydroxide sealant. SPSS 19.0 software package was used for data analysis. RESULTS: Of 39 patients in the experimental group, only 1 sinus was not healed,the total effective rate was 97.44%;Of 39 patients in the control group,9 sinuses were not healed, the total effective rate was 76.92%. The difference between the two groups was statistically significant. CONCLUSIONS: The results show that the effect of diode laser in the treatment of sinus chronic apical abscess is better, which is worthy of wide application.

New Nano-Film Single-Rivet Patent Ductus Arteriosus Occluders: A Prospective, Randomized and Double-blind Study.

Nitinol alloy occluders are widely used in the transcatheter intervention treatment of congenital heart diseases like patent ductus arteriosus (PDA). However, nitinol alloy contains high levels of nickel, which can lead to toxic effects in the immune and hematopoietic systems if released in sufficient quantities. A new type of single-rivet occluder coated with nano-film has been developed to limit the release of nickel. In total, 23 patients were recruited and randomly assigned to the experimental group (n=12) with the new nano-film single-rivet occluders or the control group (n=11) with the traditional occluders. One case in the control group was lost to follow-up. The remaining 22 cases were followed up at 24 h, 7 days, 1 month, 3 months, and 6 months after the procedure. There were no statistically significant differences in routine blood test, alanine aminotransferase, creatinine, and troponin between the experimental and control groups. Serum nickel concentration in both two groups increased at 24 h after the procedure, peaked at 1 month, and returned to preoperative levels at 6 months. Serum nickel levels in the experimental group were significantly lower than in the control group at 24 h, 7 days, 1 month, and 3 months after the procedure. These data suggested that the nano-film coating effectively prevented nickel release from the new occluders, and therefore has a preferable safety profile.

Enterovirus 71-induced has-miR-21 contributes to evasion of host immune system by targeting MyD88 and IRAK1.

Enterovirus71(EV71), the etiological agent of hand-foot-and-mouth disease, has increasingly become a public health challenge around the world. Type I interferons (IFNs) are an important family of cytokines that regulate innate and adaptive immune responses to pathogens.These pathways are tightly regulated by the host to prevent an inappropriate cellular response, but viruses can modulate these pathways to proliferate and spread. In this study, we demonstrated that EV71 evades the immune surveillance system to proliferate by activating microRNA-21. We demonstrated that EV71 infection upregulates miR-21, which in turn suppresses EV71-triggered type I IFN production, thus promoting EV71 replication. Furthermore, we demonstrated that miR-21 targets the myeloid differentiation factor 88(MyD88) and interleukin-1 receptor-associated kinase 1(IRAK1), which are involved in EV71-induced type I IFN production.

[The experimental study of biomimetic artificial cartilage fabrication in vitro and ectopic chondrogenesis in vivo].

Tri-dimensional poly (DL-lactic-co-glycolic acid) (PLGA) scaffolds were fabricated using a rapid prototyping (RP) technique and the gene of human bone morphogenetic protein 2 (hBMP-2) was transferred into rabbit bone marrow stromal cells (MSCs) via recombinant adeno-associated virus vectors (rAAV-hBMP-2). Thirty-two PLGA scaffolds, size (4 mm X 4 mm X 4 mm), were coated with collagen type I and equally divided into 2 groups. In group A, each scaffold was loaded with 2 X 10(4) hBMP-2 (+) MSCs to establish a hBMP-2 (+) MSCs/PLGA composite. In group B, each scaffold was loaded with 2 X 10(4) hBMP-2 (-) MSCs to establish a hBMP-2 (-) MSCs/PLGA composite. The composites in both groups were cultured for subcutaneous implantation in nude mice. All animals were killed 30 days after implantation and the differentiation of composites was evaluated. As a result, MSCs infected with rAAV-hBMP-2 efficiently expressed hBMP-2 protein. RP-based PLGA scaffolds had ideal microarchitecture. The diameters of macropore and micropore of the scaffolds were 300 microm and 3-5 microm, respectively. At 3-5 days after culture, a number of seeding cells well grew on the scaffolds of both groups. The composites in group A had chondrogenesis ability in vivo and the expression of collagen type II was positive. In group B, however, only polymers and fiber tissues were predominantly found. The percentage of polymer remnant area was significantly lower in group A than in group B (P<0.01). Our results therefore indicate that RP-based PLGA scaffolds efficiently coated with collagen type I have good biocompatibility with hBMP-2 (+) MSCs and the techniques developed in this study may favor cartilage tissue engineering.

[Morphology research of the rat sciatic nerve bridged by collage-heparin sulfate scaffold].

OBJECTIVE: To observe the treating effect of collage-heparin sulfate after the 10 mm rat sciatic nerve defect was bridged by it. METHODS: A new kind of nervous tissue engineering scaffold was produced by freeze-drying technique from collagen-heparin sulfate. Thirty-two SD rats were randomly divided into A, B, C and D groups. Sciatic nerve defect in group A was bridged by collagen-heparin sulfate. In group B, sciatic nerve was bridged by auto-nerve transplantation. Group C was the blank control group. Animals in group D were normal. And 10 mm sciatic nerve defect was bridged in the experiment. Thirty-six weeks after the operation, the experimental animals were detected by HRP labeled retrograde trace, HE staining, toluidine staining, silvering staining, S100, GAP-43 and NF immunohistological staining, MBP immunofluorescence staining and transmission electron microscope to observe the nerve regeneration inducing effect of this new scaffold. RESULTS: Nine months after operation, the collage-heparin sulfate scaffold was replaced by newly regenerated nerve. The number of HRP labeled spinal cord anterior horn cells and the area of sensation nerve fiber at the posterior horn were similar with that was repaired by auto-nerve. GAP-43, NF and S100 labeled regenerated nerve fiber had passed the total scaffold and entered the distal terminal. The regenerated nerve fibers were paralleled, lineage arranged, coincide with the prearranged regenerating "channel" in the collagen-heparin sulfate scaffold. MBP immunofluorescence staining also proved that the newly regenerated nerve fiber could be ensheathed. In the experimental group, the area of myelinated nerve fiber and the thickness of the myelin sheath had no obvious difference with that of the group repaired by auto-nerve, except that the density of the regenerated myelinated sheath fiber was lower than that of the control group. CONCLUSION: Nervous tissue engineering scaffold produced by collagen-heparin sulfate can guide the regeneration of nerve fibers. The nerve function recovers fine. This kind of material has great application potential.

Repair of radius defect with bone-morphogenetic-protein loaded hydroxyapatite/collagen-poly(L-lactic acid) composite.

OBJECTIVE: To explore the method to repair bone defect with bone-morphogenetic-protein loaded hydroxyapatite/collagen-poly(L-lactic acid) composite. METHODS: 18 adult beagle dogs were randomly divided into 3 groups. In Group A, bone-morphogenetic-protein (BMP) loaded hydroxyapatite/collagen-poly(L-lactic acid) (HAC-PLA) scaffold was implanted in a 2 cm diaphyseal defect in the radius. In Group B, unloaded pure HAC-PLA scaffold was implanted in the defects. No material was implanted in Group C (control group). The dogs were sacrificed 6 months postoperatively. Features of biocompatibility, biodegradability and osteoinduction were evaluated with histological, radiological examinations and bone mineral density (BMD) measurements. RESULTS: In Group A, the radius defect healed after the treatment with BMP loaded HAC-PLA. BMD at the site of the defect was higher than that of the contralateral radius. Fibrous union developed in the animals of the control group. CONCLUSIONS: BMP not only promotes osteogenesis but also accelerates degradation of the biomaterials. Optimized design parameters of a three-dimensional porous biomaterial would give full scope to the role of BMP as an osteoinductive growth factor.

Effect of type I collagen on the adhesion, proliferation, and osteoblastic gene expression of bone marrow-derived mesenchymal stem cells.

OBJECTIVE: To investigate the effects of porous poly lactide-co-glycolide (PLGA) modified by type I collagen on the adhesion, proliferation, and differentiation of rabbit marrow-derived mesenchymal stem cells (MSCs). METHODS: The third generation MSCs isolated from mature rabbits by density gradient centrifugation were cultured at different initial concentrations on 0.3 cm x 1.2 cm x 2.0 cm 3-D porous PLGA coated by type I collagen in RPMI 1640 containing 10% fetal calf serum, while cultured on PLGA without type I collagen as control. The cells adhesive and proliferative behavior at 7, 14, and 21 days after inoculation was assessed by determining the incorporation rate of [(3)H]-TdR. In order to examine MSCs differentiation, the expression of osteoblasts marker genes, osteocalcin (OCN), alkaline phosphatase (ALP), osteopontin (OPN) mRNA, were evaluated by reverse transcription-polymerase chain reaction (RT-PCR), and further more, the cell morphology at 21 days was also observed by scanning electron microscope (SEM). RESULTS: Type I collagen promoted cell adhesion on PLGA. The valve was significantly higher than controls (6 h, 2144 cpm+/-141 cpm vs. 1797 cpm+/-118 cpm, P=0.017; 8 h, 2311 cpm+/-113 cpm vs. 1891 cpm+/-103 cpm, P=0.01). The cells which cultured on PLGA coated with type I collagen showed significantly higher cell proliferation than controls on the 7 th day (1021 cpm+/-159 cpm vs. 451 cpm+/-67 cpm, P=0.002), the 14th day (1472 cpm+/-82 cpm vs. 583 cpm+/-67 cpm, P<0.001) and 21 th day (1728 cpm+/-78 cpm vs. 632 cpm+/-55 cpm, P<0.001). Osteoblasts markers, OCN, ALP, OPN mRNA, were all detected on PLGA coated by type I collagen on the 21 th day, but OCN, OPN mRNA could not be found in controls. Spindle and polygonal cells well distributed on the polymer coated by type I collagen while cylindric or round cells in controls. CONCLUSIONS: Type I collagen is effective in promoting the adhesion, proliferation and differentiation of MSCs on PLGA.

[Effects of collagen I coating on the porous poly-lactide-co-glycolid on adhesion, proliferation, and differentiation of mesenchymal stem cells].

OBJECTIVE: To investigate the effects of collagen I on the adhesion, proliferation, and differentiation of MSCs on PLGA. METHODS: Collagen I was added onto the surface of pores in pieces of 3-D porous poly-lactide-co-glycolid (PLGA). Bone marrow-derived mesenchymal stem cells (MSCs) were obtained from New Zealand rabbits and were cultured for 3 generations, inoculated into the pores of PLGA pieces with the volume of 0.3 cm x 1.2 cm x 2.0 cm, and then cultured in solution with [(3)H]-thymidine deoxyribose (TdR). PLGA pieces not coated by collagen I were used as controls. The incorporation rate of [(3)H]-TdR was detected 2, 4, 6, and 8 hours, and 7, 14, and 21 days after culture, shown in count per minute (CPM) value, to determine the adhesion and proliferation of the MSCs. RT-POCR was used to examine the expressions of mRNA of the osteoblast markers: osteocalcin (OCN), alkaline phosphatase (ALP), and osteopontin (OPN). Scanning electron microscopy (SEM) was used to observe the morphology of MSCs. RESULTS: The CPM value since 6 hours after culture between the experimental group and control group began to be significantly different (both P < 0.05) The CPM values 7, 14, and 21 days after culture between the experimental group and control groups (P < 0.05 or P < 0.01). OCN, ALP, and OPN mRNA were expressed in MSCs of the experimental group and only ALP mRNA was weakly expressed in the control group. SEM showed the distribution of spindle and polygonal cells in the pores of the 3-D PLGA pieces and distribution of cylindrical or round cells in the control group. CONCLUSION: Collagen I is effective in promoting the adhesion, proliferation, and differentiation of MSCs on PLGA.

[Preparation and osteogenic activity of combining calcium phosphate cement with bone morphogenetic protein composite as a bone graft material].

OBJECTIVES: To construct new type of bone graft material by combining calcium phosphate cement (CPC) with bone morphogenetic protein (BMP), and then to detect its osteogenic activity. METHODS: The surface of CPC and CPC/BMP composite were observed by scanning electron microscope (SEM). CPC and CPC/BMP pellets were separately implanted into the thigh muscle pouches of mice. Samples obtained at different times were tested by histological analysis, SEM, organic substance detection, and alkaline phosphatase (ALP) measurement to observe the induced ectopic bone formation. RESULTS: Under SEM, the CPC and CPC/BMP composite was found to consist primarily of platy crystals, granular crystals and some small rod-like crystals with micropores about 10-50 microm in size. BMP about 1-5 microm in size was seen like micro globules distributing evenly in the micropores. Newly formed cartilage or bone was not found in the CPC group. In the CPC/BMP group, mesenchymal cells were proliferated and abundant cartilage was found in one week. Woven bone appeared at 2 weeks. New bone formation increased with bone marrow at 4 weeks. At 8 weeks, the implanted CPC/BMP became heterogeneous and a lot of collapsed granules were observed. At the end of 16 weeks, mature lamellar bone appeared and the volume of the implanted CPC/BMP became smaller. One week after implantation, the ALP increased evidently in the CPC/BMP groups and reached the highest level at the 4th week, which was about 168 U/L. The content of organic substance in specimens increased from 22% to 39% by the end of the 16th week, showing the continuous calcification and formation of new bone. SEM also showed that the CPC/BMP composite had good potentiality of ectopic bone induction, and the new bone formed accompanied by the slow degradation of the material. CONCLUSION: The results of this study suggested that the CPC/BMP composite could be used as material for bone graft substitute.

Hepatitis C virus-related heat-insoluble cryoglobulinemia and thrombotic microangiopathy.

Heat-insoluble cryoglobulinemia is rare, and its pathogenesis and comorbidities remain poorly understood. Here, the authors report a case of hepatitis C virus (HCV)-related heat-insoluble cryoglobulinemia associated with thrombotic microangiopathy and cryoglobulin-occlusive membranoproliferative glomerulonephritis. The patient, a 57-year-old woman, presented with acute kidney injury, thrombocytopenia, anemia with schistocytes, high levels of serum HCV RNA of HCV genotype 2a, rheumatoid factor positivity and high levels of serum immunoglobulin (Ig) M and Igκ. The patient's serum was positive for cryoglobulin at 4°C, and the precipitate required heating to 47°C for dissolution. Cryoglobulin immunofixation was positive for monoclonal IgM and Igκ and polyclonal IgG. However, immunofixation of the cryoglobulin supernatant was negative. Histological examination of renal biopsy revealed a membranoproliferative type I glomerulonephritis. The patient was treated with plasmapheresis, corticosteroids and antiviral therapy of peginterferon plus ribavirin, but symptoms only partially resolved.

A modified evisceration technique with scleral quadrisection and porous polyethylene implantation.

PURPOSE: To propose and evaluate a modified evisceration technique that aiming to minimize the extrusion or exposure and improve motility of the implant. DESIGN: Interventional prospective study. METHODS: There were 154 patients referred to our clinic from March 1, 2003 to March 1, 2007. All the patients underwent the primary evisceration and implantation of a porous polyethylene implant using the modified technique, which included quadrisecting the sclera, suturing the implant with each rectus muscle through the scleral petal, and then covering the implant with 2 layers of the sclera. Main outcome measures were complications such as conjunctival dehiscence, implant extrusion, implant exposure, significant enophthalmos, superior sulcus deformity or orbital cellulitis, and cosmetic outcome. RESULTS: All patients received porous polyethylene implants with 18 mm or larger sphere. In a mean 3.5 years follow-up period (range, 1 to 5 years), there was no case of conjunctival dehiscence, implant extrusion, implant exposure, significant enophthalmos, superior sulcus deformity, or orbital cellulitis. The cosmetic appearance and implant mobility were satisfactory. CONCLUSIONS: This technique appears to be an excellent modification for anophthalmic socket reconstruction.