bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developmental effects of oral exposure to diethylstilbestrol on mouse placenta
Authors: Nagao Tetsuji , Kagawa Nao , Saito Yoshiaki , Komada Munekazu 
Published: June 2012

ABSTRACTPlacental growth and function are of biological significance in that placental tissue promotes prenatal life and the maintenance of pregnancy. Exposure to synthetic estrogens causes embryonic mortality and placental growth restriction in mice. The aim of the present study was to examine the effects of diethylstilbestrol (DES) on placenta in mice. DES at 1, 5, 10 or 15 µg kg–1 day–1, or 17β‐estradiol (E2) at 50 µg kg–1 day–1, was administered orally to ICR mice on days 4 through to 8 of gestation. Expression of ERα, ERβ, ERRβ or ERRγ mRNA in the junctional or labyrinth zone of the placentas on day 13 was assessed using RT‐PCR, as well as the embrynic mortality, embryonic and placental weight, histological changes of labyrinth and ultrastructural changes of the trophoblast giant cells (TGCs). Embryo mortalities in the DES 10 and 15 µg kg–1 day–1 groups were markedly increased. No significant changes in embryonic and placental weight were observed in any DES‐ or E2‐exposed groups. Expression of ERα mRNA in the junctional zone with male embryos in the 5 µg kg–1 day–1 group was significantly higher than that in the control, whereas expression was not determined in the 15 µg kg–1 day–1 group. Histological observation revealed that the placentas exposed to DES at 10 µg kg–1 day–1 lacked the developing labyrinth. Ultrastructural observation of the TGCs showed poor rough‐surfaced endoplasmic reticulum in the DES 10 µg kg–1 day–1 group. The present data suggest that developmental changes induced by DES may be related to interference with the nutrition and oxygen exchange between mother and embryo or decreased protein synthesis, resulting in a high frequency of embryo mortality. Copyright © 2012 John Wiley & Sons, Ltd.
The effect of grain size on the biocompatibility, cell–materials interface, and mechanical properties of microwave‐sintered bioceramics
Authors: Veljović Djordje , Čolić Miodrag , Kojić Vesna , Bogdanović Gordana , Kojić Zvezdana , Banjac Andrijana , Palcevskis Eriks , Petrović Rada , Janaćković Djordje 
Published: June 2012

AbstractThe effect of decreasing the grain size on the biocompatibility, cell–material interface, and mechanical properties of microwave‐sintered monophase hydroxyapatite bioceramics was investigated in this study. A nanosized stoichiometric hydroxyapatite powder was isostatically pressed at high pressure and sintered in a microwave furnace in order to obtain fine grained dense bioceramics. The samples sintered at 1200°C, with a density near the theoretical one, were composed of micron‐sized grains, while the grain size decreased to 130 nm on decreasing the sintering temperature to 900°C. This decrease in the grain size certainly led to increases in the fracture toughness by much as 54%. An in vitro investigation of biocompatibility with L929 and human MRC‐5 fibroblast cells showed noncytotoxic effects for both types of bioceramics, while the relative cell proliferation rate, cell attachment and metabolic activity of the fibroblasts were improved with decreasing of grain size. An initial in vivo investigation of biocompatibility by the primary cutaneous irritation test showed that both materials exhibited no irritation properties. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3059–3070, 2012.
Poly(vinyl alcohol)/collagen/hydroxyapatite hydrogel: Properties and in vitro cellular response
Authors: Song Wei , Markel David C. , Jin Xin , Shi Tong , Ren Weiping 
Published: June 2012

AbstractThe objective of this study was to develop “bone‐like” poly(vinyl alcohol) (PVA)/hydroxyapatite (HA)/type I collagen (Col) hydrogel composites that stimulate adhesion, proliferation, and differentiation of osteoblastic cells. The hydrogel composites were prepared by mixing PVA with nanoscale HA and Col using a physical mixing method. The concentration of the components was optimized during formulation development. PVA/Col/HA hydrogels were characterized for viscoelasticity, degree of swelling, mechanical strength, embedded erythromycin drug release, and cellular response of both osteoblastic MC3T3 cells and RAW 264.7 macrophage cells. Compressive strength tests confirmed that the PVA coating possessed greater elasticity and was mechanically enhanced by the freeze‐thaw treatment. PVA/Col/HA gel is biocompatible and nontoxic to MC3T3 preosteoblasts, and the reinforcement from HA and Col reduced the inflammatory response from macrophages. Our findings demonstrate that PVA composites are biocompatible, and enhance cell adhesion, proliferation, and differentiation in vitro. We propose that PVA/Col/HA hydrogels represent one of the promising implant surface coating matrices for the improvement of implant osseointegration. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3071–3079, 2012.
Processing–structure–functional property relationship in organic–inorganic nanostructured scaffolds for bone‐tissue engineering: The response of preosteoblasts
Authors: Depan D. , Misra R. D. K. 
Published: June 2012

AbstractWe elucidate here for the first time the structure–processing–functional property relationship in chitosan (CS)‐based scaffolds, where molecular machinery governing proliferation and growth of osteoblasts is mediated by nanostructured carbon. The interconnected network structure of organic–inorganic scaffolds was obtained by covalent linkage of carboxyl group of functionalized single‐walled carbon nanohorn with the amine group of CS. The molecular‐scale dispersibility of functionalized nanostructured carbon was an important physicochemical factor influencing cellular interactions and biological response. Furthermore, it was beneficial in promoting the biocompatibility and the degradation product of the scaffolds. The hydrophilicity, good water retention ability, and interconnected porous structure of organic–inorganic scaffolds enabled pronounced cell attachment and proliferation and enhanced the stability toward enzymatic degradation. The infiltration of cells and colonization of the pores of the scaffolds and cellular interactions were promoted due to covalent linkage of nanostructured carbon with CS. Additionally, the interconnectivity of porous scaffolds facilitated cells to infiltrate inside the pores of CS‐nanostructured scaffolds, implying that nanostructured carbon merits consideration in tissue engineering. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3080–3091, 2012.
Bone tissue, cellular, and molecular responses to titanium implants treated by anodic spark deposition
Authors: Sverzut Alexander T. , de Albuquerque Gustavo C. , Crippa Grasiele E. , Chiesa Roberto , Valle Cinzia Della , de Oliveira Paulo T. , Beloti Marcio M. , Rosa Adalberto L. 
Published: June 2012

AbstractA myriad of titanium (Ti) surface modifications has been proposed to hasten the osseointegration. In this context, the aim of this study was to perform histomorphometric, cellular, and molecular analyses of the bone tissue grown in close contact with Ti implants treated by anodic spark deposition (ASD‐AK). Acid‐etched (AE) Ti implants either untreated or submitted to ASD‐AK were placed into dog mandibles and retrieved at 3 and 8 weeks. It was noticed that both implants, AE and ASD‐AK, were osseointegrated at 3 and 8 weeks. Histomorphometric analysis showed differences between treatments only for bone‐to‐implant contact, being higher on AE implants. Although not backed by histomorphometric results, gene expression of key bone markers was higher for bone grown in close contact with ASD‐AK and for cells harvested from these fragments and cultured until subconfluence. Cell proliferation at days 7 and 10 and alkaline phosphatase activity at day 10 was higher on AE surfaces. No statistical significant difference was noticed for extracellular matrix mineralization at 17 days. Our results have shown that the Ti fixtures treated by ASD‐AK allowedin vivoosseointegration and induced higher expression of key markers of osteoblast phenotype, suggesting that this surface treatment could be considered to produce implants for clinical applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3092–3098, 2012.
Platelet‐rich plasma loaded in situ‐formed hydrogel enhances hyaline cartilage regeneration by CB1 upregulation
Authors: Lee Hye‐Rim , Park Kyung Min , Joung Yoon Ki , Park Ki Dong , Do Sun Hee 
Published: June 2012

AbstractThe efficacy of three‐dimensional (3D) culture on the proliferation and maturation of chondrocytes seeded into a hydrogel scaffold was assessed. Three types of hydrogel were prepared for the 3D culture of primary isolated chondrocytes. Chondrocyte proliferation was assessed using a live/dead viability/cytotoxicity assay and semiquantitative RT‐PCR after 3D culture in hydrogel. Cylindrical defects in the center of rat xyphoids were used for the implantation of platelet‐rich plasma (PRP)/hydrogel composites. Rats were killed at day 7 postoperatively and evaluated histochemically and immunohistologically. Xyphoid chondrocytes proliferated well with time in hydrogels. In the PRP‐containing hydrogels, xyphoid defects displayed early formation of chondroid matrix with massive peripheral infiltration of spindle cells. These results were consistent with Safranin‐O staining for proteoglycans and immunohistochemistry for type II collagen. Gene expression analyses in vitro revealed aggrecan, type II collagen, and ChM‐1 and CB1 upregulation by PRP/hydrogel. PRP/hydrogel provided a suitable environment for hyaline cartilaginous regeneration, leading to anti‐inflammation by significant increase of CB1 and inhibiting vascular ingrowth via considerable upregulation of ChM‐1. The results provide a valuable reference for the clinical application of hydrogel scaffolds for hyaline cartilage regeneration, as well as the use of autologous PRP to improve cellular proliferation and maturation of xyphoid repair. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3099–3107, 2012.
Directed osteogenic differentiation of human mesenchymal stem/precursor cells on silicate substituted calcium phosphate
Authors: Cameron Kate , Travers Paul , Chander Chaman , Buckland Tom , Campion Charlie , Noble Brendon 
Published: June 2012

AbstractInsufficient, underactive, or inappropriate osteoblast function results in serious clinical conditions such as osteoporosis, osteogenesis imperfecta and fracture nonunion and therefore the control of osteogenesis is a medical priority.In vitromesenchymal stem cells (MSCs) can be directed to form osteoblasts through the addition of soluble factors such as β‐glycerophosphate, ascorbic acid, and dexamethasone; however this is unlikely to be practical in the clinical setting. An alternative approach would be to use a scaffold or matrix engineered to provide cues for differentiation without the need for soluble factors. Here we describe studies using Silicate‐substituted calcium phosphate (Si‐CaP) and unmodified hydroxyapatite (HA) to test whether these materials are capable of promoting osteogenic differentiation of MSCs in the absence of soluble factors. Si‐CaP supported attachment and proliferation of MSCs and induced osteogenesis to a greater extent than HA, as evidenced through upregulation of the osteoblast‐related genes:Runx2(1.2 fold),Col1a1(2 fold),Pth1r(1.5 fold), andBglap(1.7 fold)Dmp1(1.1 fold), respectively. Osteogenic‐associated proteins, alkaline phosphatase (1.4 fold), RUNX2, COL1A1, and BGLAP, were also upregulated and there was an increased production of mineralized bone matrix (1.75 fold), as detected by the Von Kossa Assay. These data indicate that inorganic substrates are capable of directing the differentiation programme of stem cells in the absence of known chemical drivers and therefore may provide the basis for bone repair in the clinical setting. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A:13–22, 2013.
Architectural characterization of organotypic cultures of H400 and primary rat keratinocytes
Authors: Khan Erum , Shelton Richard M. , Cooper Paul R. , Hamburger John , Landini Gabriel 
Published: June 2012

AbstractOrganotypic epithelial structures can be cultured using primary or immortalized keratinocytes. However, there has been little detailed quantitative histological characterization of such cultures in comparison with normal mucosal architecture. The aim of this study is to identify morphological markers of tissue architecture that can be used to monitor tissue structure, maturation, and differentiation and to enable quantitative comparison of organotypic cultures (OCs) with normal oral mucosa. OCs of oral keratinocytes [immortalized H400 or primary rat keratinocytes (PRKs)] were generated using the three scaffolds of de‐epidermalized dermis (DED), polyethylene terephthalate (PET), and collagen gels for up to 14 days. Cultures and normal epithelium were analyzed immunohistochemically and by using the semi‐quantitative reverse transcriptase polymerase chain reaction (sq‐RT‐PCR) for E‐cadherin, desmoglein‐3, plakophilin, involucrin, cytokeratins‐1, ‐5, ‐6, ‐10, ‐13, and Ki67. The epithelial thickness of OCs was measured in stained sections using image processing. Histological analysis revealed that air–liquid interface (ALI) cultures generated stratified organotypic epithelial structures by 14‐days. The final thickness of these cultures as well as the degree of maturation/stratification (including stratum corneum formation) varied significantly depending on the scaffold used. For certain scaffolds, the immunohistochemical profiles obtained recapitulated those of normal oral epithelium indicating comparable in vitro differentiation and proliferation. In conclusion, quantitative microscopy approaches enabled unbiased architectural characterization of OCs. The scaffold materials used in the present study (DED, collagen type‐I and PET) differentially influenced cell behavior in OCs of oral epithelia. H400 and PRK OCs on DED at the ALI demonstrated similar characteristics in terms of gene expression and protein distribution to the normal tissue architecture. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:3227–3238, 2012.
In vitro degradation, biocompatibility, and in vivo osteogenesis of poly(lactic‐co‐glycolic acid)/calcium phosphate cement scaffold with unidirectional lamellar pore structure
Authors: He Fupo , Ye Jiandong 
Published: June 2012

AbstractThe aim of this study was to investigate the in vitro degradation, cytocompatibility, and in vivo osteogenesis of poly(lactic‐co‐glycolic acid) (PLGA)/calcium phosphate cement (CPC) scaffold with unidirectional lamellar pore structure. CPC‐based scaffold was fabricated by unidirectional freeze casting, and PLGA was used to improve the mechanical properties of the CPC‐based scaffold, which covered the surface of the pore wall as coating. The in vitro degradation results demonstrated that the PLGA/CPC scaffold had good degradability. The degradation of PLGA film on the surface of the scaffold made the CPC matrix exposed, which facilitated cell response and osteogenesis. Rat bone mesenchymal stem cells (rMSCs) were seeded on the PLGA/CPC composite scaffold. Cell viability, proliferation, and differentiation on the PLGA/CPC composite scaffold were evaluated. The results showed that viable rMSCs attached on the surface of pore wall gradually penetrated into the internal pores of the scaffold as prolongation of culture time. In addition, the rMSCs seeded on the scaffold exhibited good proliferation and growing alkaline phosphatase activity. The scaffold was implanted in the defects in distal end of femora of New Zealand white rabbits. Histological evaluation indicated that the PLGA/CPC scaffold with unidirectional lamellar pore structure had good biocompatibility and effective osteogenesis. These results suggest PLGA/CPC composite scaffold with unidirectional lamellar pore structure is a promising scaffold for bone tissue engineering. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:3239–3250, 2012.
The in vitro and in vivo biocompatibility evaluation of heparin–poly(ε‐caprolactone) conjugate for vascular tissue engineering scaffolds
Authors: Ye Lin , Wu Xin , Duan Hong‐Yong , Geng Xue , Chen Bing , Gu Yong‐Quan , Zhang Ai‐Ying , Zhang Jian , Feng Zeng‐Guo 
Published: June 2012

AbstractPoly(ε‐caprolactone) (PCL) was conjugated with heparin and fabricated into nonwoven tubular scaffold by electrospinning. The dynamic contact angle analysis revealed the hydrophilicity improvement due to heparin concentrating on the conjugate surface. The microbicinchoninic acid and quartz crystal microbalance measurements implied that the conjugate can significantly reduce the absorption of plasma protein, such as albumin and fibrinogen, indicative of the good blood biocompatibility. As evidenced by Enzyme Linked Immunosorbent Assay, the electrospun conjugate scaffolds possessed a higher loading capability of vascular endothelial growth factor (VEGF) than that of the blank PCL in aqueous solution via static interaction. The viability of loaded VEGF was evaluated by cell culture and adhesion tests. The amount and morphology of cells were substantially improved after VEGF was loaded into scaffolds exhibiting excellent cell biocompatibility. To assess the in vivo biocompatibility, a tubular scaffold (L = 4 cm, D = 2 mm) was transplanted into dog's femoral artery. The scaffold patency was inspected by carotid artery angiography 4 weeks after implantation. The explanted scaffold was also investigated by histological analysis including hematoxyline eosin, Millere Masson (collagen and elastin), and von Kossa (calcium) stain. Furthermore, von Willebrand factor immunohistochemical stain was performed to examine the formation of endothelial layer. The conjugate shows the potential to be used as scaffold materials in vascular tissue engineering. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:3251–3258, 2012.
Biomimetic coating on bioactive glass‐derived scaffolds mimicking bone tissue
Authors: Bellucci D. , Sola A. , Gentile P. , Ciardelli G. , Cannillo V. 
Published: June 2012

AbstractBioceramic “shell” scaffolds, with a morphology resembling the cancellous bone microstructure, have been recently obtained by means of a new protocol, developed with the aim to overcome the limits of the conventional foam replication technique. Because of their original microstructure, the new samples combine high porosity, permeability, and manageability. In this study, for the first time, the novel bioactive glass shell scaffolds are provided with a gelatin‐based biomimetic coating to realize hybrid implants which mimic the complex morphology and structure of bone tissue. Moreover, the presence of the coating completely preserves the in vitro bioactivity of the bioactive glass samples, whose surfaces are converted into hydroxyapatite after a few days of immersion in a simulated body fluid solution (SBF). © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:3251–3258, 2012.
Evaluation of bone regeneration, angiogenesis, and hydroxyapatite conversion in critical‐sized rat calvarial defects implanted with bioactive glass scaffolds
Authors: Bi Lianxiang , Jung Steve , Day Delbert , Neidig Katie , Dusevich Vladimir , Eick David , Bonewald Lynda 
Published: June 2012

AbstractBioactive glasses are biocompatible materials that convert to hydroxyapatite in vivo, and potentially support bone formation, but have mainly been available in particulate and not scaffold form. In this study, borosilicate and borate bioactive glass scaffolds were evaluated in critical‐sized rat calvarial defects. Twelve‐week‐old rats were implanted with 45S5 silicate glass particles and scaffolds of 1393 silicate, 1393B1 borosilicate, and 1393B3 borate glass. After 12 weeks, the defects were harvested, stained with hematoxylin and eosin to evaluate bone regeneration, Periodic Acid Schiff to quantitate blood vessel area, and von Kossa and backscatter SEM to estimate newly mineralized bone and hydroxyapatite conversion of bioactive glasses. The amount of new bone was 12.4% for 45S5, 8.5% for 1393, 9.7% for 1393B1, and 14.9% for 1393B3 (*p = 0.04; cf. 1393 and 1393B1). Blood vessel area was significantly higher (p = 0.009) with 45S5 (3.8%), with no differences among 1393 (2.0%), 1393B1 (2.4%), or 1393B3 (2.2%). Percent von Kossa‐positive area was 18.7% for 45S5, 25.4% for 1393, 29.5% for 1393B1, and 30.1% for 1393B3, significantly higher (p = 0.014) in 1393B1 and 1393B3 glasses than in 45S5. 45S5 and 1393B3 converted completely to HA in vivo. The 1393B3 glass provided greater bone formation and may be more promising for bone defect repair due to its capacity to be molded into scaffolds. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:3267–3275, 2012.
Channeled scaffolds implanted in adult rat brain
Authors: Martínez‐Ramos Cristina , Vallés‐Lluch Ana , Verdugo José Manuel García , Ribelles José Luis Gómez , Barcia Albacar Juan Antonio , Orts Amparo Baiget , Soria López José Miguel , Pradas Manuel Monleón 
Published: June 2012

AbstractScaffolds with aligned channels based on acrylate copolymers, which had previously demonstrated good compatibility with neural progenitor cells were studied as colonizable structures bothin vitrowith neural progenitor cells andin vivo, implanted without cells in two different locations, in the cortical plate of adult rat brains and close to the subventricular zone.In vitro, neuroprogenitors colonize the scaffold and differentiate into neurons and glia within its channels. When implantedin vivoimmunohistochemical analysis by confocal microscopy for neural and endothelial cells markers demonstrated that the scaffolds maintained continuity with the surrounding neural tissue and were colonized by GFAP‐positive cells and, in the case of scaffolds implanted in contact with the subventricular zone, by neurons. Local angiogenesis was evidenced in the interior of the scaffolds' pores. New axons and neural cells from the adult neural niche abundantly colonized the biomaterial's inner structure after 2 months, and minimal scar formation was manifest around the implant. These findings indicate the biocompatibility of the polymeric material with the brain tissue and open possibilities to further studies on the relevance of factors such as scaffold structure, scaffold seeding and scaffold placement for their possible use in regenerative strategies in the central nervous system. The development of neural interfaces with minimized glial scar and improved tissue compatibility of the implants may also benefit from these results. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:3276–3286, 2012.
Preparation and in vivo degradation of controlled biodegradability of electrospun silk fibroin nanofiber mats
Authors: Kim Ji Heui , Park Chan Hum , Lee Ok‐Joo , Lee Jung‐Min , Kim Jong Wook , Park Young Hwan , Ki Chang Seok 
Published: June 2012

AbstractControlled biodegradability of biomaterials is very important because different functionality and durability are required for various purposes and for specific tissues and organs. From this point of view, silk‐based biomaterials have poor usability because of uncontrollable degradability, even though silk fibroin (SF) is highly biocompatible and a number of studies on silk biomaterials have been published to date. In this study, we prepared SF nanofiber mats that were recrystallized in different ways. These mats were fabricated by electrospinning with ethanol/propanol mixtures of various blend ratios, and their biodegradabilities in vitro and in vivo were evaluated using rats. As a result, we can suggest an established method to modulate the degradability of SF nanofibrous materials based on long‐term (12 months) observations. In particular, we elucidated how the SF nanofibers are degraded and incorporated with surrounding tissue by observation of fluorescein isothiocyanate–labeled SF nanofiber in vivo. Our findings suggest a method for controlling the degradation rate of SF for medical applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:3287–3295, 2012.