Assessing cellular response to functionalized α-helical peptide hydrogels

α-Helical peptide hydrogels are decorated with a cell-binding peptide motif (RGDS), which is shown to promote adhesion, proliferation, and differentiation of PC12 cells. Gel structure and integrity are maintained after functionalization. This opens possibilities for the bottom-up design and engineering of complex functional scaffolds for 2D and 3D cell cultures.</p

Active screen plasma nitriding enhances cell attachment to polymer surfaces

Active screen plasma nitriding (ASPN) is a well-established technique used for the surface modification of materials, the result of which is often a product with enhanced functional performance. Here we report the modification of the chemical and mechanical properties of ultra-high molecular weight poly(ethylene) (UHMWPE) using 80:20 (v/v) N2/H2 ASPN, followed by growth of 3T3 fibroblasts on the treated and untreated polymer surfaces. ASPN-treated UHMWPE showed extensive fibroblast attachment within 3 h of seeding, whereas fibroblasts did not successfully attach to untreated UHMWPE. Fibroblast coated surfaces were maintained for up to 28 days, monitoring their metabolic activity and morphology throughout. The chemical properties of the ASPN-treated UHMWPE surface were studied using X-ray photoelectron spectroscopy, revealing the presence of C N, C N, and C N chemical bonds. The elastic modulus, surface topography, and adhesion properties of the ASPN-treated UHMWPE surface were studied over 28 days during sample storage under ambient conditions and during immersion in two commonly used cell culture media

Improving cellular migration in tissue-engineered laryngeal scaffolds

ObjectiveTo modify the non-porous surface membrane of a tissue-engineered laryngeal scaffold to allow effective cell entry.MethodsThe mechanical properties, surface topography and chemistry of polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane were characterised. A laser technique introduced surface perforations. Micro computed tomography generated porosity data. Scaffolds were seeded with cells, investigated histologically and proliferation studied. Incubation and time effects were assessed.ResultsLaser cutting perforated the polymer, connecting the substructure with the ex-scaffold environment and increasing porosity (porous, non-perforated = 87.9 per cent; porous, laser-perforated at intensities 3 = 96.4 per cent and 6 = 89.5 per cent). Cellular studies confirmed improved cell viability. Histology showed cells adherent to the scaffold surface and cells within perforations, and indicated that cells migrated into the scaffolds. After 15 days of incubation, scanning electron microscopy revealed an 11 per cent reduction in pore diameter, correlating with a decrease in Young's modulus.ConclusionIntroducing surface perforations presents a viable method of improving polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane as a tissue-engineered scaffold

Comparing physicochemical properties of printed and hand cast biocements designed for ligament replacement

In order to combat the low regenerative capabilities of ligaments, full `bone to bone' replacements are required, which will integrate with bone while providing a smooth transition to the replacement soft tissue (tissues surrounding organs in the body, not being bone). This study investigated the use of three-dimensional powder printing technology to form calcium phosphate brackets, previously used for forming bespoke scaffold geometries, to 95±0·1% accuracy of their original computer aided design. The surface and internal structures of the printed samples were characterised both chemically and morphologically and compared with hand moulded cements in the dry state and after 3 days of immersion in phosphate buffered saline. X-ray diffraction, Raman spectroscopy and SEM all showed the presence of brushite in the hand moulded samples and brushite and monetite within the printed samples. Furthermore, the printed structures have a higher level of porosity in the dry state in comparison to the hand moulded samples (36±2·2% compared to 24±0·7%) despite exhibiting a compressive strength of almost double the hand cast material. Although the compressive strength of the printed cements decreases after the 3 day immersion, there was no significant difference between the printed and hand moulded cements under the same conditions. Three-dimensional powder printing technology has enabled the manufacture of bespoke calcium phosphate brackets with properties similar to those reported for hand moulded cements

Comparison of conventional BLUP and single-step genomic BLUP evaluations for yearling weight and carcass traits in Hanwoo beef cattle using single trait and multi-trait models

[EN] Hanwoo, an important indigenous and popular breed of beef cattle in Korea, shows rapid growth and has high meat quality. Its yearling weight (YW) and carcass traits (backfat thickness, carcass weight- CW, eye muscle area, and marbling score) are economically important for selection of young and proven bulls. However, measuring carcass traits is difficult and expensive, and can only be performed postmortem. Genomic selection has become an appealing procedure for genetic evaluation of these traits (by inclusion of the genomic data) along with the possibility of multi-trait analysis. The aim of this study was to compare conventional best linear unbiased prediction (BLUP) and single-step genomic BLUP (ssGBLUP) methods, using both single-trait (ST-BLUP, ST-ssGBLUP) and multi-trait (MT-BLUP, MT-ssGBLUP) models to investigate the improvement of breeding-value accuracy for carcass traits and YW. The data comprised of 15,279 phenotypic records for YW and 5,824 records for carcass traits, and 1,541 genotyped animals for 34,479 single-nucleotide polymorphisms. Accuracy for each trait and model was estimated only for genotyped animals by five-fold cross-validation. ssGBLUP models (ST-ssGBLUP and MT-ssGBLUP) showed ~19% and ~36% greater accuracy than conventional BLUP models (ST-BLUP and MT-BLUP) for YW and carcass traits, respectively. Within ssGBLUP models, the accuracy of the genomically estimated breeding value for CW increased (19%) when ST-ssGBLUP was replaced with the MT-ssGBLUP model, as the inclusion of YW in the analysis led to a strong genetic correlation with CW (0.76). For backfat thickness, eye muscle area, and marbling score, ST- and MT-ssGBLUP models yielded similar accuracy. Thus, combining pedigree and genomic data via the ssGBLUP model may be a promising way to ensure acceptable accuracy of predictions, especially among young animals, for ongoing Hanwoo cattle breeding programs. MT-ssGBLUP is highly recommended when phenotypic records are limited for one of the two highly correlated genetic traits.Mehrban, H.; Lee, DH.; Naserkheil, M.; Moradi, MH.; Ibáñez-Escriche, N. (2019). Comparison of conventional BLUP and single-step genomic BLUP evaluations for yearling weight and carcass traits in Hanwoo beef cattle using single trait and multi-trait models. PLoS ONE. 1-13. https://doi.org/10.1371/journal.pone.0223352S113Choi, T. J., Alam, M., Cho, C. I., Lee, J. G., Park, B., Kim, S., … Roh, S. H. (2015). Genetic parameters for yearling weight, carcass traits, and primal-cut yields of Hanwoo cattle1. Journal of Animal Science, 93(4), 1511-1521. doi:10.2527/jas.2014-7953Choy, Y. H., Park, B. H., Choi, T. J., Choi, J. G., Cho, K. H., Lee, S. S., … Kim, H. S. (2012). Estimation of Relative Economic Weights of Hanwoo Carcass Traits Based on Carcass Market Price. Asian-Australasian Journal of Animal Sciences, 25(12), 1667-1673. doi:10.5713/ajas.2012.12397Joo, S.-T., Hwang, Y.-H., & Frank, D. (2017). Characteristics of Hanwoo cattle and health implications of consuming highly marbled Hanwoo beef. Meat Science, 132, 45-51. doi:10.1016/j.meatsci.2017.04.262Park, B., Choi, T., Kim, S., & Oh, S.-H. (2013). National Genetic Evaluation (System) of Hanwoo (Korean Native Cattle). Asian-Australasian Journal of Animal Sciences, 26(2), 151-156. doi:10.5713/ajas.2012.12439Chen, L., Vinsky, M., & Li, C. (2014). Accuracy of predicting genomic breeding values for carcass merit traits in Angus and Charolais beef cattle. Animal Genetics, 46(1), 55-59. doi:10.1111/age.12238Rolf, M. M., Garrick, D. J., Fountain, T., Ramey, H. R., Weaber, R. L., Decker, J. E., … Taylor, J. F. (2015). Comparison of Bayesian models to estimate direct genomic values in multi-breed commercial beef cattle. Genetics Selection Evolution, 47(1). doi:10.1186/s12711-015-0106-8Mehrban, H., Lee, D. H., Moradi, M. H., IlCho, C., Naserkheil, M., & Ibáñez-Escriche, N. (2017). Predictive performance of genomic selection methods for carcass traits in Hanwoo beef cattle: impacts of the genetic architecture. Genetics Selection Evolution, 49(1). doi:10.1186/s12711-016-0283-0Misztal, I., Aggrey, S. E., & Muir, W. M. (2013). Experiences with a single-step genome evaluation. Poultry Science, 92(9), 2530-2534. doi:10.3382/ps.2012-02739Hayes, B. J., Bowman, P. J., Chamberlain, A. J., & Goddard, M. E. (2009). Invited review: Genomic selection in dairy cattle: Progress and challenges. Journal of Dairy Science, 92(2), 433-443. doi:10.3168/jds.2008-1646VanRaden, P. M., Van Tassell, C. P., Wiggans, G. R., Sonstegard, T. S., Schnabel, R. D., Taylor, J. F., & Schenkel, F. S. (2009). Invited Review: Reliability of genomic predictions for North American Holstein bulls. Journal of Dairy Science, 92(1), 16-24. doi:10.3168/jds.2008-1514Misztal, I., Legarra, A., & Aguilar, I. (2009). Computing procedures for genetic evaluation including phenotypic, full pedigree, and genomic information. Journal of Dairy Science, 92(9), 4648-4655. doi:10.3168/jds.2009-2064Legarra, A., Aguilar, I., & Misztal, I. (2009). A relationship matrix including full pedigree and genomic information. Journal of Dairy Science, 92(9), 4656-4663. doi:10.3168/jds.2009-2061Aguilar, I., Misztal, I., Johnson, D. L., Legarra, A., Tsuruta, S., & Lawlor, T. J. (2010). Hot topic: A unified approach to utilize phenotypic, full pedigree, and genomic information for genetic evaluation of Holstein final score. Journal of Dairy Science, 93(2), 743-752. doi:10.3168/jds.2009-2730Ibáñez-Escriche, N., Forni, S., Noguera, J. L., & Varona, L. (2014). Genomic information in pig breeding: Science meets industry needs. Livestock Science, 166, 94-100. doi:10.1016/j.livsci.2014.05.020Onogi, A., Ogino, A., Komatsu, T., Shoji, N., Simizu, K., Kurogi, K., … Iwata, H. (2014). Genomic prediction in Japanese Black cattle: Application of a single-step approach to beef cattle. Journal of Animal Science, 92(5), 1931-1938. doi:10.2527/jas.2014-7168Gordo, D. G. M., Espigolan, R., Tonussi, R. L., Júnior, G. A. F., Bresolin, T., Magalhães, A. F. B., … de Albuquerque, L. G. (2016). Genetic parameter estimates for carcass traits and visual scores including or not genomic information1. Journal of Animal Science, 94(5), 1821-1826. doi:10.2527/jas.2015-0134Lee, J., Cheng, H., Garrick, D., Golden, B., Dekkers, J., Park, K., … Fernando, R. (2017). Comparison of alternative approaches to single-trait genomic prediction using genotyped and non-genotyped Hanwoo beef cattle. Genetics Selection Evolution, 49(1). doi:10.1186/s12711-016-0279-9Tsuruta, S., Misztal, I., Aguilar, I., & Lawlor, T. J. (2011). Multiple-trait genomic evaluation of linear type traits using genomic and phenotypic data in US Holsteins. Journal of Dairy Science, 94(8), 4198-4204. doi:10.3168/jds.2011-4256Forni, S., Aguilar, I., & Misztal, I. (2011). Different genomic relationship matrices for single-step analysis using phenotypic, pedigree and genomic information. Genetics Selection Evolution, 43(1). doi:10.1186/1297-9686-43-1Xiang, T., Nielsen, B., Su, G., Legarra, A., & Christensen, O. F. (2016). Application of single-step genomic evaluation for crossbred performance in pig1. Journal of Animal Science, 94(3), 936-948. doi:10.2527/jas.2015-9930Chen, C. Y., Misztal, I., Aguilar, I., Legarra, A., & Muir, W. M. (2011). Effect of different genomic relationship matrices on accuracy and scale1. Journal of Animal Science, 89(9), 2673-2679. doi:10.2527/jas.2010-3555Guo, G., Zhao, F., Wang, Y., Zhang, Y., Du, L., & Su, G. (2014). Comparison of single-trait and multiple-trait genomic prediction models. BMC Genetics, 15(1), 30. doi:10.1186/1471-2156-15-30Jia, Y., & Jannink, J.-L. (2012). Multiple-Trait Genomic Selection Methods Increase Genetic Value Prediction Accuracy. Genetics, 192(4), 1513-1522. doi:10.1534/genetics.112.144246Browning, S. R., & Browning, B. L. (2007). Rapid and Accurate Haplotype Phasing and Missing-Data Inference for Whole-Genome Association Studies By Use of Localized Haplotype Clustering. The American Journal of Human Genetics, 81(5), 1084-1097. doi:10.1086/521987Aguilar, I., Misztal, I., Legarra, A., & Tsuruta, S. (2011). Efficient computation of the genomic relationship matrix and other matrices used in single-step evaluation. Journal of Animal Breeding and Genetics, 128(6), 422-428. doi:10.1111/j.1439-0388.2010.00912.xVanRaden, P. M. (2008). Efficient Methods to Compute Genomic Predictions. Journal of Dairy Science, 91(11), 4414-4423. doi:10.3168/jds.2007-0980Saatchi, M., McClure, M. C., McKay, S. D., Rolf, M. M., Kim, J., Decker, J. E., … Taylor, J. F. (2011). Accuracies of genomic breeding values in American Angus beef cattle using K-means clustering for cross-validation. Genetics Selection Evolution, 43(1), 40. doi:10.1186/1297-9686-43-40Lee, S. H., Choi, B. H., Lim, D., Gondro, C., Cho, Y. M., Dang, C. G., … Hong, S. K. (2013). Genome-Wide Association Study Identifies Major Loci for Carcass Weight on BTA14 in Hanwoo (Korean Cattle). PLoS ONE, 8(10), e74677. doi:10.1371/journal.pone.0074677Gordo, D. G. M., Espigolan, R., Bresolin, T., Fernandes Júnior, G. A., Magalhães, A. F. B., Braz, C. U., … Albuquerque, L. G. (2018). Genetic analysis of carcass and meat quality traits in Nelore cattle1. Journal of Animal Science, 96(9), 3558-3564. doi:10.1093/jas/sky228Visscher, P. M., Medland, S. E., Ferreira, M. A. R., Morley, K. I., Zhu, G., Cornes, B. K., … Martin, N. G. (2006). Assumption-Free Estimation of Heritability from Genome-Wide Identity-by-Descent Sharing between Full Siblings. PLoS Genetics, 2(3), e41. doi:10.1371/journal.pgen.0020041Christensen, O. F., Madsen, P., Nielsen, B., Ostersen, T., & Su, G. (2012). Single-step methods for genomic evaluation in pigs. Animal, 6(10), 1565-1571. doi:10.1017/s1751731112000742Aguilar, I., Misztal, I., Tsuruta, S., Wiggans, G. R., & Lawlor, T. J. (2011). Multiple trait genomic evaluation of conception rate in Holsteins. Journal of Dairy Science, 94(5), 2621-2624. doi:10.3168/jds.2010-3893Baloche, G., Legarra, A., Sallé, G., Larroque, H., Astruc, J.-M., Robert-Granié, C., & Barillet, F. (2014). Assessment of accuracy of genomic prediction for French Lacaune dairy sheep. Journal of Dairy Science, 97(2), 1107-1116. doi:10.3168/jds.2013-7135Lourenco, D. A. L., Tsuruta, S., Fragomeni, B. O., Masuda, Y., Aguilar, I., Legarra, A., … Misztal, I. (2015). Genetic evaluation using single-step genomic best linear unbiased predictor in American Angus1. Journal of Animal Science, 93(6), 2653-2662. doi:10.2527/jas.2014-8836Calus, M. P., & Veerkamp, R. F. (2011). Accuracy of multi-trait genomic selection using different methods. Genetics Selection Evolution, 43(1). doi:10.1186/1297-9686-43-26Jiang, J., Zhang, Q., Ma, L., Li, J., Wang, Z., & Liu, J.-F. (2015). Joint prediction of multiple quantitative traits using a Bayesian multivariate antedependence model. Heredity, 115(1), 29-36. doi:10.1038/hdy.2015.9Ismael, A., Løvendahl, P., Fogh, A., Lund, M. S., & Su, G. (2017). Improving genetic evaluation using a multitrait single-step genomic model for ability to resume cycling after calving, measured by activity tags in Holstein cows. Journal of Dairy Science, 100(10), 8188-8196. doi:10.3168/jds.2017-13122Cheng, H., Kizilkaya, K., Zeng, J., Garrick, D., & Fernando, R. (2018). Genomic Prediction from Multiple-Trait Bayesian Regression Methods Using Mixture Priors. Genetics, 209(1), 89-103. doi:10.1534/genetics.118.300650Kemper, K. E., Bowman, P. J., Hayes, B. J., Visscher, P. M., & Goddard, M. E. (2018). A multi-trait Bayesian method for mapping QTL and genomic prediction. Genetics Selection Evolution, 50(1). doi:10.1186/s12711-018-0377-yGoddard, M. E., & Hayes, B. J. (2009). Mapping genes for complex traits in domestic animals and their use in breeding programmes. Nature Reviews Genetics, 10(6), 381-391. doi:10.1038/nrg257

Host macrophage response to injectable hydrogels derived from ECM and α-helical peptides

Tissue engineering materials play a key role in how closely the complex architectural and functional characteristics of native healthy tissue can be replicated. Traditional natural and synthetic materials are superseded by bespoke materials that cross the boundary between these two categories. Here we present hydrogels that are derived from decellularised extracellular matrix and those that are synthesised from de novo α-helical peptides. We assess in vitro activation of murine macrophages to our hydrogels and whether these gels induce an M1-like or M2-like phenotype. This was followed by the in vivo immune macrophage response to hydrogels injected into rat partial-thickness abdominal wall defects. Over 28 days we observe an increase in mononuclear cell infiltration at the hydrogel-tissue interface without promoting a foreign body reaction and see no evidence of hydrogel encapsulation or formation of multinucleate giant cells. We also note an upregulation of myogenic differentiation markers and the expression of anti-inflammatory markers Arginase1, IL-10, and CD206, indicating pro-remodelling for all injected hydrogels. Furthermore, all hydrogels promote an anti-inflammatory environment after an initial spike in the pro-inflammatory phenotype. No difference between the injected site and the healthy tissue is seen after 28 days, indicating full integration. These materials offer great potential for future applications in regenerative medicine and towards unmet clinical needs

Effect of plasma surface modification on the biocompatibility of UHMWPE

In this paper active screen plasma nitriding (ASPN) is used to chemically modify the surface of UHMWPE. This is an unexplored and new area of research. ASPN allows the homogeneous treatment of any shape or surface at low temperature; therefore, it was thought that ASPN would be an effective technique to modify organic polymer surfaces. ASPN experiments were carried out at 120 °C using a dc plasma nitriding unit with a 25% N2 and 75% H2 atmosphere at 2.5 mbar of pressure. UHMWPE samples treated for different time periods were characterized by nanoindentation, FTIR, XPS, interferometry and SEM. A 3T3 fibroblast cell line was used for in vitro cell culture experiments. Nanoindentation of UHMWPE showed that hardness and elastic modulus increased with ASPN treatment compared to the untreated material. FTIR spectra did not show significant differences between the untreated and treated samples; however, some changes were observed at 30 min of treatment in the range of 1500–1700 cm−1 associated mainly with the presence of N−H groups. XPS studies showed that nitrogen was present on the surface and its amount increased with treatment time. Interferometry showed that no significant changes were observed on the surfaces after the treatment. Finally, cell culture experiments and SEM showed that fibroblasts attached and proliferated to a greater extent on the plasma-treated surfaces leading to the conclusion that ASPN surface treatment can potentially significantly improve the biocompatibility behaviour of polymeric materials

Structural changes to resorbable calcium phosphate bioceramic aged <i>in vitro</i>

This work investigates the effect of mammalian cell culture conditions on 3D printed calcium phosphate scaffolds. The purpose of the studies presented was to characterise the changes in scaffold properties in physiologically relevant conditions. Differences in crystal morphologies were observed between foetal bovine serum-supplemented media and their unsupplemented analogues, but not for supplemented media containing tenocytes. Scaffold porosity was found to increase for all conditions studied, except for tenocyte-seeded scaffolds. The presence of tenocytes on the scaffold surface inhibited any increase in scaffold porosity in the presence of extracellular matrix secreted by the tenocytes. For acellular conditions the presence or absence of sera proteins strongly affected the rate of dissolution and the distribution of pore diameters within the scaffold. Exposure to high sera protein concentrations led to the development of significant numbers of sub-micron pores, which was otherwise not observed. The implication of these results for cell culture research employing calcium phosphate scaffolds is discussed

Hadronic B decays: Supersymmetric enhancement and a simple spectator model

Two aspects of hadronic B decays are investigated. Firstly, the supersymmetric enhancement of hadronic b decays by gluino penguin processes is studied through their effect on the Wilson coefficients of the effective Hamiltonian. Secondly, hadronization of the final state quarks is studied through a simple phase space spectator model.Comment: 24 pages, REVTEX, minor additional text and some references adde

Seaweed polysaccharide-based hydrogels used for the regeneration of articular cartilage

This manuscript provides an overview of the in vitro and in vivo studies reported in the literature focusing on seaweed polysaccharides based hydrogels that have been proposed for applications in regenerative medicine, particularly, in the field of cartilage tissue engineering. For a better understanding of the main requisites for these specific applications, the main aspects of the native cartilage structure, as well as recognized diseases that affect this tissue are briefly described. Current available treatments are also presented to emphasize the need for alternative techniques. The following part of this review is centered on the description of the general characteristics of algae polysaccharides, as well as relevant properties required for designing hydrogels for cartilage tissue engineering purposes. An in-depth overview of the most well known seaweed polysaccharide, namely agarose, alginate, carrageenan and ulvan biopolymeric gels, that have been proposed for engineering cartilage is also provided. Finally, this review describes and summarizes the translational aspect for the clinical application of alternative systems emphasizing the importance of cryopreservation and the commercial products currently available for cartilage treatment.Authors report no declarations of interest. Authors thank the Portuguese Foundation for Science and Technology (FCT) for the PhD fellowship of Elena G. Popa (SFRH/BD/64070/2009) and research project (MIT/ECE/0047/2009). The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no REGPOT-CT2012-316331-POLARIS