Use of Polyglycolic Acid Unwoven and Woven Fibers for Tendon Engineering In Vitro

2005 ◽  
Vol 288-289 ◽  
pp. 7-10 ◽  
Author(s):  
Xian Wei ◽  
P.H. Zhang ◽  
W.Z. Wang ◽  
Z.Q. Tan ◽  
De Jun Cao ◽  
...  

Objective: To compare biocompatibility, degradation, and mechanical properties of polyglycolic acid (PGA) unwoven and woven fibers as scaffolding materials for tendon engineering in vitro. Methods: Three kinds of PGA fibers were included in this study. PGA raw material (Purac Co, Holland) was spun into single PGA filaments that were further twisted into woven fibers (PGA- 1). PGA filaments (Nantong Holycon, China) were twisted into woven fibers (PGA-2) as well. PGA-1 and PGA-2 served as experimental groups 1 and 2, while unwoven PGA fibers (Albany Co, USA) served as control group. Three types of PGA fibers were made into cord-like scaffolds that mimic tendon shape and compared with each other for biocompatibility, degradation and biomechanical properties. Avian tenocytes were isolated from digital flexor tendon and expanded in vitro. Cells of the second passage were seeded onto the PGA scaffolds. In the first 2 weeks, the cell- PGA constructs were in vitro cultured without tension and observed for cell adhesion and matrix production. The constructs were then cultured under dynamic loading in a bioreactor for another 2 weeks followed by gross and histological examinations. Results: PGA unwoven fibers have the median diameter of 10µm, while PGA-1 and PGA-2 fibers have the median diameters of 200µm and 60µm, respectively. Microscopy showed that tenocytes adhered well to all three types of PGA fibers in the first 10 days and produced abundant matrices. However, cells showed poor viability on PGA-2 fibers after 10 days, yet good viability on the other two PGA fibers over 2 weeks of observation period. H&E staining showed that there were viable cells and abundant matrices in the control and PGA-1 groups, but not in PGA-2 group after 4 weeks of in vitro culture. Additionally, PGA unwoven fibers degraded faster than woven fibers (PGA-1 and -2). Interestingly, the PGAtenocyte constructs formed tendon-like tissue after 4 weeks of in vitro culture grossly and histologically. Furthermore, mechanical test demonstrated that both PGA woven fibers had much higher tensile strength than unwoven fibers. Conclusion: Different PGA fibers have different biocompatibility with seeded tenocytes. PGA woven fibers could bear more intense mechanical loading and degrade slower than unwoven fibers, which is essential for in vitro generation of tendon tissue. Thus PGA woven fibers might serve as a proper form of scaffolding material for in vitro tendon engineering in a bioreactor.

2013 ◽  
Vol 18 (3) ◽  
pp. 101-106 ◽  
Author(s):  
Sissy Maria Mendes Machado ◽  
Diego Bruno Pinho do Nascimento ◽  
Robson Costa Silva ◽  
Sandro Cordeiro Loretto ◽  
David Normando

OBJECTIVE: To evaluate in vitro the effects of tooth whitening using gel with Amorphous Calcium Phosphate (ACP) on the bond strength of metal brackets. METHODS: Thirty-six bovine incisors were sectioned at the crown-root interface, and the crowns were then placed in PVC cylinders. The specimens were divided into 3 groups (n = 12) according to whitening treatment and type of gel used, as follows: G1 (control) = no whitening; G2 = whitening with gel not containing ACP (Whiteness Perfect - FGM), G3 = whitening with gel containing ACP (Nite White ACP - Discus Dental). Groups G2 and G3 were subjected to 14 cycles of whitening followed by an interval of 15 days before the bonding of metal brackets. Shear bond strength testing was performed on a Kratos universal test machine at a speed of 0.5 mm/min. After the mechanical test, the specimens were assessed to determine the adhesive remnant index (ARI). The results were subjected to ANOVA, Tukey's test and Kruskal-Wallis test (5%). RESULTS: Significant differences were noted between the groups. Control group (G1 = 11.10 MPa) showed a statistically higher shear bond strength than the groups that underwent whitening (G2 = 5.40 Mpa, G3 = 3.73 MPa), which did not differ from each other. There were no significant differences between the groups in terms of ARI. CONCLUSION: Tooth whitening reduces the bond strength of metal brackets, whereas the presence of ACP in the whitening gel has no bearing on the results.


2021 ◽  
Author(s):  
Tairen Chen ◽  
Mengjing Wu ◽  
Yuting Dong ◽  
Bin Kong ◽  
Yufang Cai ◽  
...  

Abstract Purpose: Whether FSH promotes follicle growth by inhibiting the Hippo signalling pathway.METHODS: Ovaries were cultured in vitro into a control group (no intervention), an FSH group (0.3 IU/mL FSH), and a VP group (10 µg/mL vetiporfin). HE staining and follicle counts were performed at each stage after 3 hours of in vitro culture. Immunohistochemistry was performed to study the expression levels of LATS2, YAP, PLATS2, and PYAP, and their expression levels in each group were also analysed by Western blot.The number of secondary follicles was significantly increased in the FSH group, the arrangement of granulosa cells was neater, the nuclear fixation was reduced, and the number of atretic follicles was decreased in the VP group. The number of secondary follicles was significantly increased, the number of atretic follicles was reduced, and granulosa cell nuclear consolidation was reduced in the VP+FSH group. Immunohistochemistry showed that LATS2 and YAP expression levels were significantly increased and PLATS2 and PYAP expression levels were relatively decreased in the FSH group, PYAP and PLATS2 expression levels were significantly increased and YAP expression was significantly decreased in the VP group, and YAP and LATS2 expression levels were significantly increased and PYAP and PLATS2 expression levels were significantly decreased in the VP+FSH group. By Western blot, LATS2 and YAP were elevated and PYAP and PLAT2 were decreased in the FSH group, LATS2 and YAP were decreased and PYAP and PLATS were significantly elevated in the VP group, and LATS2 and YAP were elevated and PYAP and PLATS2 were decreased in the VP+FSH group.CONCLUSION: FSH promotes follicle development by inhibiting the Hippo signalling pathway.


2010 ◽  
Vol 22 (1) ◽  
pp. 307
Author(s):  
M. M. Souza ◽  
N. Z. Saraiva ◽  
C. S. Oliveira ◽  
T. A. D. Tetzner-Nanzeri ◽  
R. Vantini ◽  
...  

The use of fetal bovine serum (FBS) as protein supplementation in IVP of bovine embryos has presented difficulties because it can introduce a number of pathogenic components in culture systems, can be related to the birth of calf with abnormal growth and development, and precludes the establishment of the actual nutritional needs of the embryo, because it contains an unlimited variety of substances. This study evaluated the replacement of the FBS in the medium of in vitro culture (IVC) of bovine embryos, using the knockout serum replacer (KSR) as protein supplementation and culture medium conditioned with stem cells. Therefore, bovine oocytes from ovaries of slaughterhouse were selected and matured in vitro in TCM-199 medium supplemented with 10% FBS (Crypion), 1.0 μg mL-1 FSH (Pluset®, Calier, Barcelona, Spain), 50 μg mL-1 hCG (Profasi®, Serono, Geneva, Switzerland), 1.0 μg mL-1 estradiol (Sigma E-2758, Sigma Chemical, St. Louis, MO, USA), 0.2 mM sodium pyruvate, and 83.4 μg mL-1 amikacin for 24 h. After that, 1144 oocytes were fertilized in IVF-TALP medium containing 6 mg mL-1 of BSA. After 18 to 22 h, the zygotes were cultured in SOF + 5% FBS (group 2); SOF + 5% KSR (group 3); SOF (5% FBS) + 10% SOF (5% FBS) conditioned by stem cells (group 4); or SOF (5% KSR) + 10% SOF (5% KSR) conditioned by stem cells (group 5), in an atmosphere of 5% O2 at 38.5°C for 8 days. A control group outside the controlled atmosphere was added, supplemented with 5% FBS (group 1). The SOF medium supplemented with 5% FBS or KSR was conditioned by stem cells and added to SOF medium for the culture of embryo at a concentration of 10%. The rates of cleavage and production of blastocysts were assessed 48 hours and 7 days after IVF, respectively, and analyzed by chi-square test, with a significance level of 5% in the statistical program Minitab® (release 14.1, Minitab, State College, PA, USA). On the eighth day, the TUNEL test for determination of the percentage of apoptosis and the differential staining technique for determination of inner cell mass (ICM) and trophoblast (TF) were performed. The results were submitted to ANOVA, followed by comparing the means by Tukey’s test using the program GraphPad Prism (GraphPad, San Diego, CA, USA). The treatments did not differ in the production of embryos, being similar to the control group: G1 = 31.75% (74/233), G2 = 35.26% (79/224), G3 = 32.70% (74/226), G4 = 28.76% (63/219), and G5 = 26.85% (65/242). With regard to the assessment of embryonic quality, the treatments showed similar results to the control groups. No differences were observed among groups both in color and ICM/TF ratio (G1 = 0.60, G2 = 0.62, G3 =0.65, G4 = 0.60, and G5 = 0.60). Furthermore, the TUNEL showed no significant difference in the percentage of apoptosis among groups (G1 = 7.10%, G2 = 3.76%, G3 = 5.58%, G4 = 4.50%, and G5 = 4.11%). The data obtained so far indicate that it is possible to produce embryos in vitro by replacing the FBS in the culture, achieving results similar to those obtained with serum. Financial support: FAPESP 2007/58506-6.


2014 ◽  
Vol 26 (1) ◽  
pp. 155
Author(s):  
L. Baldoceda ◽  
C. Vigneault ◽  
P. Blondin ◽  
C. Robert

Mitochondria play an important role during early mammalian embryo development through their diverse cellular functions, in particular creating balance between production of ATP by electron transport chain and oxidative stress. Embryonic mitochondria are inherited maternally and independently of the nuclear genome. They show limited activity during the early developmental stages before embryonic genome activation. It has been shown that in vitro culture (IVC) has an adverse effect on mitochondrial function in embryos. So far several attempts have been performed to improve and rescue the impaired mitochondria. It has been shown that vitamin K2 (a membrane-bound electron carrier, similar to ubiquinone) was used to rescue mitochondrial dysfunction and resulted in more efficient ATP production in eukaryotic cells (Vos et al. 2012 Science 336, 1306–1310). Therefore, the aim of the present study was to investigate the effects of supplementation of vitamin K2 on mitochondrial activity and blastocyst rate. Cumulus–oocytes complexes (n = 687) recovered from slaughtered animals, were matured and fertilized in vitro according to our standard procedures. After fertilization, zygotes were cultured in SOF media supplemented with 10 mg mL–1 BSA. At 96 h post-fertilization, vitamin K2 was added to the culture media (n = 448 oocytes). On Day 7, treatment embryos were compared with untreated controls (n = 239 oocytes). In vitro culture was carried out at 38.5°C under 5% CO2, 7% O2, and 88% N2. Differences among groups in blastocyst yield were analysed by ANOVA. Mitochondrial activity data was analysed by unpaired 2-tailed t-tests. Results show that the vitamin K2-treated group had a significantly (P < 0.05) higher blastocyst rate (+8.6%), expanded blastocyst rate (+7.8%), as well as better morphological quality compared with the control group. Furthermore, to evaluate mitochondria activity, pools of embryos of each treatment were labelled with a specific dye for active mitochondria (Mitotracker Red). A significantly higher intensity of Mitotracker Red (P < 0.05) was observed in the vitamin K2 treatment versus control group, as measured by fluorescent microscopy. In conclusion, for the first time, our data prove that supplementation of vitamin K2 during IVC of bovine embryos increases blastocyst rates and embryo quality. Future studies will focus on gene expression to identify targets implicated in impaired mitochondrial activity in in vitro bovine embryo production.


2016 ◽  
Vol 28 (2) ◽  
pp. 139
Author(s):  
C. Buemo ◽  
A. Gambini ◽  
L. Moro ◽  
R. F. Y. Martin ◽  
D. Salamone

In this study, we analysed the effects of the cloned embryo aggregation on in vitro embryo development and embryo quality by measuring blastocyst size and cell number, DNA fragmentation levels by TUNEL assay, and the relative expression of genes associated with pluripotency, apoptosis, trophoblast markers, and DNA methylation in the porcine. Cumulus-oocyte complexes were recovered from slaughterhouse ovaries by follicular aspiration. Maturation was performed in TCM for 42 to 48 h at 39°C and 5% CO2. After denudation by treatment with hyaluronidase, mature oocytes were stripped of the zona pellucida using a protease and then enucleated by micromanipulation; staining was performed with Hoëchst 33342 to observe metaphase II. Ooplasms were placed in phytohemagglutinin to permit different membranes to adhere between each other; the ooplasm membrane was adhered to a porcine fetal fibroblast from an in vitro culture. Adhered membranes of the donor cell nucleus and enucleated oocyte cytoplasm were electrofused through the use of an electric pulse (80 V for 30 μs). All reconstituted embryos were electrically activated using an electroporator in activation medium (0.3 M mannitol, 1.0 mM CaCl2, 0.1 mM MgCl2, and 0.01% polyvinyl alcohol) by a DC pulse of 1.2 kVcm for 80 μs. Then, embryos were incubated in 2 mM 6-DMAP for 3 h. In vitro culture of zona-free embryos was achieved in a well of wells system in 100 μL of SOF medium. Two experimental groups were used, one control group with a single reconstructed embryo per microwell (1×) and the other group placing 3 reconstructed embryo per microwell (3x aggregation group). Embryos were cultivated at 39°C in 5% O2, 5% CO2 for 7 days in SOF medium with a supplement of 10% fetal bovine serum on the fifth day. At Day 7, resulting blastocysts were classified according to their morphology and diameter to determine their quality. Our results showed that aggregation of 3× embryos increased blastocyst formation rate and blastocyst size of pig cloned embryos (Fisher’s test P < 0.05 and Student’s t-test P < 0.05, respectively). The DNA fragmentation levels in 3× aggregated cloned blastocysts were significantly decreased compared to 1x blastocyst (Student’s t-test P < 0.05). Levels of Oct4, Klf4, Igf2, Bax, and Dnmt1 transcripts were significantly higher in aggregated embryos, whereas Nanog levels were not affected. Transcripts of Cdx2 and Bcl-xl were essentially nondetectable (Student’s t-test P < 0.05). Our study suggests that embryo aggregation in the porcine may be beneficial for cloned embryo development and embryo quality, through a reduction in apoptotic levels and an improvement in cell reprogramming.


2021 ◽  
Vol 306 ◽  
pp. 01001
Author(s):  
Siti Fatimah Syahid ◽  
Hera Nurhayati ◽  
Budi Hartoyo

Valeriana officinalis belongs to the Valerianaceae family, is a well-known herb and medicinal plant. Plant roots are commonly used as medicine by the pharmaceutical industry. Observation on morpho-agronomic characteristics of valerian propagated in vitro is needed to determine their morphological characteristics and production in the field. The study aimed to observe the morphological characteristics of valerian derived from in vitro culture. The experiment was conducted at the Indonesian Spices and Medicinal Crops Research Institute (ISMCRI) Bogor, arranged in a Completely Randomized Design with three replications. Each replication consisted of ten individual plants. Valerian plantlets from in vitro culture were acclimatized in the greenhouse and planted in media composed of a mixture of soil, compost, and husk. Afterward, 3 months old valerian was then transferred into a polybag. The plants were harvested at 9 and 12 months after planting (MAP). Valerian plantlets from in vitro propagation were successfully acclimatized in the greenhouse. Furthermore, the morphological characteristics of the plant were similar to the parents. The yield was significantly higher at 12 MAP than 9 MAP. The tissue culture technique was prospective for valerian propagation to support rapid plant material provision for seeds or raw material for the pharmaceutical industry.


2014 ◽  
Vol 26 (1) ◽  
pp. 128
Author(s):  
C. P. Buemo ◽  
A. Gambini ◽  
I. Hiriart ◽  
D. Salamone

Somatic cell nuclear transfer (SCNT) derived blastocysts have lower cell number than IVF-derived blastocysts and their in vivo counterparts. The aim of this study was to improve the blastocyst rates and quality of SCNT blastocysts by the aggregation of genetically identical free zona pellucida (ZP) porcine clones. Cumulus–oocyte complexes were recovered from slaughterhouse ovaries by follicular aspiration. Maturation was performed in TCM for 42 to 48 h at 39°C and 5% CO2. After denudation by treatment with hyaluronidase, mature oocytes were stripped of the ZP using a protease and then enucleated by micromanipulation; staining was performed with Hoechst 33342 to observe metaphase II. Ooplasms were placed in phytohemagglutinin to permit different membranes to adhere between each other; the ooplasm membrane was adhered to a porcine fetal fibroblast from an in vitro culture. Adhered membranes of the donor cell nucleus and enucleated oocyte cytoplasm were electrofused through the use of an electric pulse (80 V for 30 μs). All reconstituted embryos (RE) were electrically activated using an electroporator in activation medium (0.3 M mannitol, 1.0 mM CaCl2, 0.1 mM MgCl2, and 0.01% PVA) by a DC pulse of 1.2 kV cm–1 for 80 μs. Then, the oocytes were incubated in 2 mM 6-DMAP for 3 h. In vitro culture of free ZP embryos was achieved in a system of well of wells in 100 μL of medium, placing 3 activated oocytes per microwell (aggregation embryo), whereas the control group was cultivated with equal drops without microwells. Embryos were cultivated at 39°C in 5% O2, 5% CO2 for 7 days in SOF medium with a supplement of 10% fetal bovine serum on the fifth day. The RE were placed in microwells. Two experimental groups were used, control group (not added 1X) and 3 RE per microwell (3X). At Day 7, resulting blastocysts were classified according to their morphology and diameter to determine their quality and evaluate if the embryo aggregation improves it. Results demonstrated that aggregation improves in vitro embryo development rates until blastocyst stage and indicated that blastocysts rates calculated over total number of oocytes do not differ between groups (Table 1). Embryo aggregation improves cleavage per oocyte and cleavage per microwell rates, presenting statistical significant differences and increasing the probabilities of higher embryo development generation until the blastocyst stage with better quality and higher diameter. Table 1.Somatic cell nuclear transfer cloning and embryo aggregation


2013 ◽  
Vol 25 (1) ◽  
pp. 254 ◽  
Author(s):  
A. Gad ◽  
U. Besenfelder ◽  
V. Havlicek ◽  
M. Hölker ◽  
M. U. Cinar ◽  
...  

The aim of this study was to examine the effect of in vitro culture conditions at specific phases of early embryonic development on the transcriptome profile of bovine blastocysts. Simmental heifers were superovulated and artificially inseminated 2 times with the same frozen–thawed commercial bull semen. Using nonsurgical endoscopic oviductal flushing technology (Besenfelder et al. 2001 Theriogenology 55, 837–845), 6 different blastocyst groups were flushed out at different time points (2-, 4-, 8-, 16-, 32-cell and morula). After flushing, embryos cultured under in vitro conditions until the blastocyst stage. Blastocysts from each group were collected and pooled in groups of 10. Complete in vivo blastocysts were produced and used as control. A unique custom microarray (Agilent) containing 42 242 oligo probes (60-mers) was used over 6 replicates of each group v. the in vivo control group to examine the transcriptome profile of blastocysts. A clear difference in terms of the number of differentially expressed genes (DEG, fold change ≥2, false discovery rate ≤0.05) has been found between groups flushed out at 2-, 4-, and 8-cell (1714, 1918, 1292 DEG, respectively) and those flushed out at 16-, 32-cell and morula stages and cultured in vitro until blastocyst stage (311, 437, 773 DEG, respectively) compared with the complete vivo group. Ontological classification of DEG showed cell death to be the most significant function in all groups. However, the longer time embryos spent under in vitro conditions, the more the percentage of DEG involved in cell death and apoptosis processes are represented in those groups. In addition, genes related to post-translational modification and gene expression processes were significantly dysregulated in all groups. Pathway analysis revealed that protein ubiquitination pathway was the dominant pathway in the groups flushed out at 2-, 4-, and 8-cells but not in the other groups flushed at later stages compared with the in vivo control group. Moreover, retinoic acid receptor activation and apoptosis signalling pathways followed the same pattern. Embryos flushed out before the time of embryonic genome activation and subsequently cultured in vitro were highly affected by culture conditions. Overall, the results of the present study showed that despite the fact that embryos originated from the same source, in vitro culture condition affected embryo quality, measured in terms of gene expression, in a stage-specific manner.


2015 ◽  
Vol 27 (1) ◽  
pp. 107
Author(s):  
R. Koppang ◽  
N. R. Mtango ◽  
M. Barcelo-Fimbres ◽  
J. P. Verstegen

Porcine somatic cell nuclear transfer (SCNT) is limited to the same or next day surgical embryo transfer due to poor culture conditions in vitro. In this study, we aimed to overcome this problem by treating SCNT embryos with scriptaid, an inhibitor of histone deacetylase (HDACi) that helps with epigenetic reprogramming of the somatic nuclei. Scriptaid was chosen over other HDACi because it has been shown to improve histone acetylation in the same pattern as that of IVF embryos as well as its low toxicity characteristic (Zhao et al. 2009 Biol. Reprod. 81, 525–530; Zhao et al. 2010 Cell Reprogram. 12, 75–78). An inbred miniature pig fetal fibroblast cell line that is known to give low blastocyst rate in culture was used as a source of donor cells transferred into enucleated oocytes. Traditional SCNT was performed; embryos were fused and chemically activated in 10 µM ionomycin for 5 min and 2 mM DMAP for 3 to 4 h before being transferred into scriptaid. Embryos were treated with 500 nM scriptaid (Zhao et al. 2010) for 18 h and the untreated group was used as control. A total of 806 oocytes were used in 8 replicates. The constructed embryos were cultured in modified porcine zygote medium 5 (mPZM-5) for 7 days at 39°C in 5% O2, 5% CO2, 90% N2 atmosphere. Cleavage rates were assessed at 2.5 days and blastocyst rates at Day 7 after activation. Data were analysed by ANOVA using GLM, and percentages were transformed using arcsin square root using Statistix 10 software (Tallahassee, FL, USA). There were no differences in cleavage rates for control group v. scriptaid (55.3 v. 49.9%; P > 0.1; Table 1). The blastocyst rate per construct showed remarkable increase in the scriptaid treated group compared with the control group (12.8 v. 2.2%; P < 0.01; Table 1). Similarly, a significant effect was observed for blastocyst per embryos cleaved where scriptaid had higher rates compared with control (25.8 v. 5.8%; P < 0.01). These results indicated that improving nuclear reprogramming of miniature porcine SCNT clones by scriptaid treatment enhanced blastocyst production during the in vitro culture of porcine embryos. Table 1.Mean (± s.e.m.) measures of embryonic development of SCNT embryos


2022 ◽  
Vol 12 (4) ◽  
pp. 673-680
Author(s):  
Min Yang ◽  
Guixi Liu ◽  
Qiao Ying

To construct the tissue engineering urethral material that is closest to the normal urethral structure in the true sense in vitro. Abdominal ADSC from a 2-month-old New Zealand white rabbit was extracted and directly compounded with non-woven polyglycolic acid (PGA) (control group) to induce the differentiation of myoblasts and epithelial-like cells in vitro and shaped into urethral structure lumen Observation group); After Gd chelating protein nano-labeling and VEGF-loaded sustained release, the rabbit model of a long urethral defect was replanted and cultured for 4 weeks, 8 weeks and 12 weeks, respectively. There was no difference in urinary tract patency rate, urinary tract infection, and renal dysfunction rate between the two groups (P > 0.05). The urine flow rate in the observation group was significantly higher than that in the control group, and the residual volume decreased (P < 0.05). The blood vessel density and CD31 percentage in the observation group increased (P < 0.05). Compared with the conventional ADSC directly in contact with the composite material to construct the urethra, in vitro induction of ADSC to myoblasts and epithelial-like cells respectively, and then use the cell membrane technology to build a tissue engineering urethral material that is closest to the normal urethral structure in the true sense, and loaded with VEGF Loop release technology can significantly improve urodynamic functions, optimize tissue engineering urethral structure and vascularization, and is expected to become a new technology for constructing new tissue engineering urethral materials.


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