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Highly porous hydrophilic and hydrophobic silica xerogels were synthesized by surface modification of silica hydrogels at ambient pressure drying. The silica hydrogels were prepared by a sol–gel polymerization of an inexpensive silica precursor (sodium silicate) under atmospheric conditions. In order to minimize shrinkage due to drying, the hydrogel surface was modified using trimethylchlorosilane (TMCS) in the presence of ethanol/n-hexane solution before ambient pressure drying (APD). Properties of the final product were investigated using Field-Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric and Differential Analysis (TG–DTA), and nitrogen physisorption studies. The final product was observed to have an extremely high specific surface area (783 m2/g) and a large cumulative pore volume (2.74 cm3/g). Highly porous hydrophilic xerogels were obtained after heat-treating the modified xerogels. At temperatures above 450 °C the surface alkyl groups (—CH3) were significantly oxidized and, consequently, the properties of the resulting xerogels were altered. Products obtained via the proposed inexpensive approach have superior properties and the method exploits an inexpensive silica source (sodium silicate). Thus it is feasible for large-scale economic industrial production. [ABSTRACT FROM AUTHOR]

Conventional epidermal cysts are generally small, slow-growing, non-tender, dome-shaped lesions. An epidermal cyst is usually asymptomatic until it is infected or enlarged to the extent that it causes damage to adjacent anatomical structures. However, few cases of giant epidermal cysts in the neck have been reported. The present case reports a giant epidermal cyst in the posterior neck, which grew to an extremely large size for >40 years without inflammation or rupture, and was misdiagnosed as a large soft tissue neoplasm. The patient exhibited depression and developed social anxiety due to the negative cosmetic consequences of the large mass. The patient underwent excision of the mass. At the follow-up examination two years postoperatively, there were no local recurrence and the psychiatric symptoms of the patient were completely resolved. To the best of our knowledge, a giant epidermal cyst growing for >40 years has not previously been reported. [ABSTRACT FROM AUTHOR]

Tumorigenicity is a well-documented risk to overcome for pluripotent or multipotent cell applications in regenerative medicine. To address the emerging demand for safe cell sources in tissue regeneration, we established a novel, protein-based reprogramming method that does not require genome integration or oncogene activation to yield multipotent fibromodulin (FMOD)-reprogrammed (FReP) cells from dermal fibroblasts. When compared with induced pluripotent stem cells (iPSCs), FReP cells exhibited a superior capability for bone and skeletal muscle regeneration with markedly less tumorigenic risk. Moreover, we showed that the decreased tumorigenicity of FReP cells was directly related to an upregulation of cyclin-dependent kinase inhibitor 2B (CDKN2B) expression during the FMOD reprogramming process. Indeed, sustained suppression of CDKN2B resulted in tumorigenic, pluripotent FReP cells that formed teratomas in vivo that were indistinguishable from iPSC-derived teratomas. These results highlight the pivotal role of CDKN2B in cell fate determination and tumorigenic regulation and reveal an alternative pluripotent/multipotent cell reprogramming strategy that solely uses FMOD protein. [ABSTRACT FROM AUTHOR]

Category: Basic Sciences/Biologics Introduction/Purpose: Metallic biomaterials (stainless steel and titanium) are most commonly used for osteotomy and fusion surgery in foot and ankle. But it results in the physical and psychological burden to the patients owing to the second surgery (hardware removal). Bioabsorbable polymer has the disadvantages such as mechanically weak strength and osteolysis. To overcome these, bioabsorbable metal such as magnesium (Mg) implant have been developed recently and applied clinically, but it has also drawback such as gas formation by the biodegradation of magnesium alloys. However, there is no study on the characteristics of the gas formation and its effect on the surrounding tissue. The purpose of this study is to identify the characteristics of gas formation and histological reaction during the absorption of Mg on surrounding tissue using in vitro and in vivo rodent model. Methods: Pure Mg plate (15 × 15 × 2 mm) was immersed in EBSS (Earle’s balanced salt solution) for in vitro immersion test for 30 days. Intramuscular implantation of Mg plate (25×5×0.25 mm) was performed on twenty-four rat’s back muscle and divided as two groups: implantation and sham surgery. Gas volume and compositions, corrosion rate and surface morphology of Mg plate, and histological exam were evaluated at every 5 days for 30 days. Results: Gas is mainly composed of H2 (2.483 ×104± 0.028 μV), but a small amount of CO (93.428±0.14 μV) and CO2 (57.18±0.53 μV) was detected in in vitro immersion test. Gas volume shows significantly higher at 5 days (0.084 ml) than other times (0.005 mL for 30 days) after implantation, and is gradually decreased over time. Corrosion rate is also faster in at 5 days and decreased over time in both in vitro and in vivo study. Surface morphology shows a lot of cracks and the formation of apatite paticles on Mg plate. Histological examination shows that nuclei gathered densely around the small and multiple air bubble pocket at 5 days and the number of gas bubbles and their volumes were reduced over time in tissue surrounded implant, and there is no difference in kidney and liver tissue between implant and sham surgery. Conclusion: The immersion of Mg in EBSS generated H2 as the major forming gas, and CO and CO2. The in vivo implantation of Mg into rats’ back muscle generated gas pockets inside the tissues because the initial gas formation rate was faster than the gas- absorbing rate; however, gas volume decreased after 15 days as the gas formation and absorbing rates became similar. The amount of Mg ions inside the liver and kidneys changed as well, but it was within a normal range, such that inflammation and tissue deformation were not found.

Category: Trauma Introduction/Purpose: In syndesmosis injury, numerous clinical and biomechanical investigations showed some concensus as follows; 1)There are no difference in stainless steel versus titanium screws. 2)A 4.5-mm screw apparently provides greater resistance to shear stress than a 3.5-mm screw. 3)The level of placement probably does not affect outcome. 4)Three-cortical versus four-cortical screw placement does not affect biomechanical stability. But, whether the syndesmosis screw should be removed prior to weight-bearing or not is still debated. The aim of this study is to compare the functional outcome between screw removal and retain group, and between diastasis and no diastasis group. Methods: One hundred twelve patients had undertaken open reduction and internal fixation due to syndesmosis injury, who divided into 4 groups; (A) syndesmotic screw removal before weight-bearing (postoperative 3 months, n=56) and (B) retained group (n=56), (C) recurrence of diastasis (n=16) and (D) no diastasis (n=40) after screw removal. Radiological diastasis, VAS, AOFAS ankle-hindfoot score, SF-12, complications (screw loosening and breakage) were evaluated between groups. Results: AOFAS ankle-hindfoot score shows 75.10±10.40 in group A, 77.07±10.60 in group B, and SF12 shows 45.78±5.68 in group A, 47.33±5.83 in group B, there is no significant difference between group A and B in AOFAS ankle-hindfoot score and SF- 12 (p=0.487, p=0.319). Radiological diastasis significantly develops (p=0.025) in group A (16/56) compare to B (2/56), but screw loosening or breakage significantly develops (p=0.001) in group B (8/56) compare to group A (0/56). AOFAS ankle-hindfoot score shows 70.33±6.22 in group C, 76.50±10.26 in group D, and SF12 shows 49.85±3.83 in group C, 47.40±8.01 in group D, there is no significant difference between group C and D in AOFAS ankle-hindfoot score and SF-12 (p=0.808, p=0.065). There is no significant difference between group C and D B in VAS, AOFAS ankle-hindfoot score and SF-12. Conclusion: Diastasis recurrence is significantly higher in removal group. But, screw retain group shows higher breakage, loosening rate than removal group. Clinical outcome such as VAS, AOFAS ankle-hindfoot score and SF-12 is no significant different in two groups.Also, if diastasis recurred, it did not affect clinical outcome. Therefore, we couldn’t conclude that syndesmotic screw removal is needed before weight-bearing (postoperaive 3 months).

A comparative study of titania–silica composite (TSC) synthesized via peptization sol–gel method was conducted. Typically, titanium hydroxide gel (Ti(OH)4) was formed by condensation of titanium oxychloride solution using adequate amount of ammonium hydroxide solution. The preformed gel was peptized either in silicic acid (SA) or nitric acid (NA) to form a sol. The composite was characterized by XRD, FTIR, SEM, TEM, TGA, and N2 physisorption studies. The XRD patterns and the TEM micrographs confirmed that thermal-derived samples of the composite, formed using silicic acid as a silica source and peptizing agent (TSC–SA), yielded TiO2–SiO2 composite with a single-phase (anatase phase); while a mixture of both anatase and rutile phases were observed in the composite (TSC–NA), where nitric acid was used as a peptizing agent. FTIR analysis showed the vibration band assignable to the Ti–O–Si bond at 945 cm−1, suggesting that titania was incorporated into silica to form a composite. Furthermore, a simple experiment of photodegradation of methyl orange in the presence of sunlight was performed to demonstrate the practical efficacy of the composites synthesized via this method. The results indicated that the calcined samples of TSC–NA-800 had the highest activity due to its superior properties. [ABSTRACT FROM AUTHOR]