Bone engineering
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Poly(ɛ-caprolactone) (PCL) is a biocompatible, biodegradable, and highly mechanically resilient FDA-approved material (for specific biomedical applications, e.g. as drug delivery devices, in sutures, or as an adhesion barrier), rendering it a promising candidate to serve bone tissue engineering. However, in vivo monitoring of PCL-based implants, as well as biodegradable implants in general, and their degradation profiles pose a significant challenge, hindering further development in the tissue engineering field and subsequent clinical adoption. To address this, photo-cross-linkable mechanically resilient PCL networks are developed and functionalized with a radiopaque monomer, 5-acrylamido-2,4,6-triiodoisophthalic acid (AATIPA), to enable non-destructive in vivo monitoring of PCL-based implants. The covalent incorporation of AATIPA into the crosslinked PCL networks does not significantly affect their crosslinking kinetics, mechanical properties, or thermal properties, but it increases their hydrolysis rate and radiopacity. Complex and porous 3D designs of radiopaque PCL networks can be effectively monitored in vivo. This work paves the way toward non-invasive monitoring of in vivo degradation profiles and early detection of potential implant malfunctions.
- MeSH
- biokompatibilní materiály chemie MeSH
- myši MeSH
- polyestery * chemie MeSH
- poréznost MeSH
- testování materiálů MeSH
- tkáňové inženýrství metody MeSH
- tkáňové podpůrné struktury * chemie MeSH
- vstřebatelné implantáty MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: Stem cells derived from adipose tissue are gaining popularity in the field of regenerative medicine due to their adaptability and clinical potential. Their rapid growth, ability to differentiate, and easy extraction with minimal complications make adipose-derived stem cells (ADSCs) a promising option for many treatments, particularly those targeting bone-related diseases. This study analyzed gene expression in canine ADSCs subjected to long-term culture and osteogenic differentiation. METHODS: ADSCs were isolated from discarded surgical waste and cultured for 14 days with and without differentiation media to assess osteogenic changes. RNA sequencing (RNA-seq) and bioinformatical analysis were performed to obtain comprehensive transcriptomic data. A total of 17793 genes were detected and GO enrichment analysis was performed on the differentially expressed genes to identify significantly up- and downregulated Biological Process (BP) GO terms across each comparison. RESULTS: The upregulation of apoptosis-regulating genes and genes related to circulatory system development suggest an induction of these processes, while the downregulation of neurogenesis and gliogenesis genes points to reciprocal regulation during osteogenic differentiation of canine ADSCs. DISCUSSION: These findings underscore the potential of ADSCs in bone regeneration and offer valuable insights for advancing tissue engineering, however further studies, including proteomic analyses, are needed to confirm these patterns and their biological significance.
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: German-speaking surgeons have left a deep imprint on the history of diagnostics and treatment of proximal femur fractures. Some of the studies published in German have fell into oblivion, others are cited until today, although sometimes quite inaccurately. The cause of such inaccuracies are citations from secondary sources due to unavailability of the original or inability to read it because of a language barrier. In the current literature, globally predominated by English articles, the "German history" of treatment of proximal femur fractures remains undervalued. The aim of the present article is to point out its contribution. MATERIALS AND METHODS: Literature search was performed in original publications and historical sources. RESULTS: The German-speaking surgeons have considerably contributed to the development of the treatment of proximal femur fractures. The analyzed period between 1847 and 1970 may be divided into three basic periods. In the first period (1847-1896), the German-speaking surgeons (Langenbeck, Trendelenburg, König, Heine, Dolinger) were the first worldwide to start treating the fractures of proximal femur operatively. In the second period (1897-1935), mainly in the 1930s, the initiative in Europe was taken over by surgeons publishing studies in France and in Belgium. Overseas, American surgeons were coming to the forefront. In Germany, only Pauwels developed the first biomechanical classification of femoral neck fractures. In the third period (1936-1970), mainly in the 1940s and 1950s, implants were designed (Pohl, Künstcher), based on close collaboration between German engineers and surgeons, that served as a model for a dynamic hip screw and a proximal femoral nail, which are currently the implants of choice in the treatment of trochanteric fractures. CONCLUSION: The historical contribution of German-speaking surgeons to understanding the issue of proximal femur fractures and their operative treatment is far more significant than presented in the historical studies published in English.
This study develops and characterizes novel biodegradable soft hydrogels with dual porosity based on N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers cross-linked by hydrolytically degradable linkers. The structure and properties of the hydrogels are designed as scaffolds for tissue engineering and they are tested in vitro with model mesenchymal stem cells (rMSCs). Detailed morphological characterization confirms dual porosity suitable for cell growth and nutrient transport. The dual porosity of hydrogels slightly improves rMSCs proliferation compared to the hydrogel with uniform pores. In addition, the laminin coating supports the adhesion of rMSCs to the hydrogel surface. However, hydrogels modified by heptapeptide RGDSGGY significantly stimulate cell adhesion and growth. Moreover, the RGDS-modified hydrogels also affect the topology of proliferating rMSCs, ranging from single-cell to multicellular clusters. The 3D reconstruction of the hydrogels with cells obtained by laser scanning confocal microscopy (LSCM) confirms cell penetration into the inner structure of the hydrogel and its corresponding microstructure. The prepared biodegradable oligopeptide-modified hydrogels with dual porosity are suitable candidates for further in vivo evaluation in soft tissue regeneration.
OBJECTIVE: Age-at-death estimation is usually done manually by experts. As such, manual estimation is subjective and greatly depends on the past experience and proficiency of the expert. This becomes even more critical if experts need to evaluate individuals with unknown population affinity or with affinity that they are not familiar with. The purpose of this study is to design a novel age-at-death estimation method allowing for automatic evaluation on computers, thus eliminating the human factor. METHODS: We used a traditional machine-learning approach with explicit feature extraction. First, we identified and described the features that are relevant for age-at-death estimation. Then, we created a multi-linear regression model combining these features. Finally, we analysed the model performance in terms of Mean Absolute Error (MAE), Mean Bias Error (MBE), Slope of Residuals (SoR) and Root Mean Squared Error (RMSE). RESULTS: The main result of this study is a population-independent method of estimating an individual's age-at-death using the acetabulum of the pelvis. Apart from data acquisition, the whole procedure of pre-processing, feature extraction and age estimation is fully automated and implemented as a computer program. This program is a part of a freely available web-based software tool called CoxAGE3D, which is available at https://coxage3d.fit.cvut.cz/. Based on our dataset, the MAE of the presented method is about 10.7 years. In addition, five population-specific models for Thai, Lithuanian, Portuguese, Greek and Swiss populations are also given. The MAEs for these populations are 9.6, 9.8, 10.8, 10.5 and 9.2 years, respectively. Our age-at-death estimation method is suitable for individuals with unknown population affinity and provides acceptable accuracy. The age estimation error cannot be completely eliminated, because it is a consequence of the variability of the ageing process of different individuals not only across different populations but also within a certain population.
- MeSH
- acetabulum * diagnostické zobrazování MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- lineární modely MeSH
- mladý dospělý MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- software * MeSH
- soudní antropologie * metody MeSH
- strojové učení * MeSH
- určení kostního věku * metody MeSH
- zobrazování trojrozměrné * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The aim of this study was to develop multifunctional magnetic poly(ε-caprolactone) (PCL) mats with antibacterial properties for bone tissue engineering and osteosarcoma prevention. To provide good dispersion of magnetic iron oxide nanoparticles (IONs), they were first grafted with PCL using a novel three-step approach. Then, a series of PCL-based mats containing a fixed amount of ION@PCL particles and an increasing content of ascorbic acid (AA) was prepared by electrospinning. AA is known for increasing osteoblast activity and suppressing osteosarcoma cells. Composites were characterized in terms of morphology, mechanical properties, hydrolytic stability, antibacterial performance, and biocompatibility. AA affected both the fiber diameter and the mechanical properties of the nanocomposites. All produced mats were nontoxic to rat bone marrow-derived mesenchymal cells; however, a composite with 5 wt.% of AA suppressed the initial proliferation of SAOS-2 osteoblast-like cells. Moreover, AA improved antibacterial properties against Staphylococcus aureus and Escherichia coli compared to PCL. Overall, these magnetic composites, reported for the very first time, can be used as scaffolds for both tissue regeneration and osteosarcoma prevention.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- Escherichia coli účinky léků MeSH
- kosti a kostní tkáň MeSH
- krysa rodu rattus MeSH
- kyselina askorbová * chemie farmakologie MeSH
- lidé MeSH
- magnetické nanočástice chemie MeSH
- nádorové buněčné linie MeSH
- nanokompozity chemie MeSH
- osteoblasty metabolismus cytologie MeSH
- osteosarkom patologie MeSH
- polyestery * chemie MeSH
- Staphylococcus aureus * účinky léků růst a vývoj MeSH
- testování materiálů MeSH
- tkáňové inženýrství * MeSH
- tkáňové podpůrné struktury chemie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Previously, a new biodegradable poly(ester urethane urea) was synthesized based on polycaprolactone-diol and fish gelatin (PU-Gel). In this work, the potential of this new material for neural tissue engineering is evaluated. Membranes with randomly oriented fibers and with aligned fibers are produced using electrospinning and characterized regarding their mechanical behavior under both dry and wet conditions. Wet samples exhibit a lower Young's modulus than dry ones and aligned membranes are stiffer and more brittle than those randomly oriented. Cyclic tensile tests are conducted and high values for recovery ratio and resilience are obtained. Both membranes exhibited a hydrophobic surface, measured by the water contact angle (WCA). Human mesenchymal stem cells from umbilical cord tissue (UC-MSCs) and human neural stem cells (NSCs) are seeded on both types of membranes, which support their adhesion and proliferation. Cells stained for the cytoskeleton and nucleus in membranes with aligned fibers display an elongated morphology following the alignment direction. As the culture time increased, higher cell viability is obtained on randomfibers for UC-MSCs while no differences are observed for NSCs. The membranes support neuronal differentiation of NSCs, as evidenced by markers for a neuronal filament protein (NF70) and for a microtubule-associated protein (MAP2).
- MeSH
- biokompatibilní materiály chemie farmakologie MeSH
- buněčná adheze účinky léků MeSH
- buněčná diferenciace účinky léků MeSH
- kultivované buňky MeSH
- lidé MeSH
- mezenchymální kmenové buňky * cytologie účinky léků metabolismus MeSH
- nervové kmenové buňky * cytologie účinky léků metabolismus MeSH
- pevnost v tahu MeSH
- polyestery * chemie farmakologie MeSH
- polyurethany * chemie farmakologie MeSH
- proliferace buněk účinky léků MeSH
- testování materiálů MeSH
- tkáňové inženýrství * metody MeSH
- tkáňové podpůrné struktury chemie MeSH
- viabilita buněk účinky léků MeSH
- želatina * chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Interfaces between AISI 304 stainless steel screws and cranial bone were investigated after long-term implantation lasting for 42 years. Samples containing the interface regions were analyzed using state-of-the-art analytical techniques including secondary ion mass, Fourier-transform infrared, Raman, and X-ray photoelectron spectroscopies. Local samples for scanning transmission electron microscopy were cut from the interface regions using the focused ion beam technique. A chemical composition across the interface was recorded in length scales covering micrometric and nanometric resolutions and relevant differences were found between peri-implant and the distant cranial bone, indicating generally younger bone tissue in the peri-implant area. Furthermore, the energy dispersive spectroscopy revealed an 80 nm thick steel surface layer enriched by oxygen suggesting that the AISI 304 material undergoes a corrosion attack. The attack is associated with transport of metallic ions, namely, ferrous and ferric iron, into the bone layer adjacent to the implant. The results comply with an anticipated interplay between released iron ions and osteoclast proliferation. The interplay gives rise to an autocatalytic process in which the iron ions stimulate the osteoclast activity while a formation of fresh bone resorption sites boosts the corrosion process through interactions between acidic osteoclast extracellular compartments and the implant surface. The autocatalytic process thus may account for an accelerated turnover of the peri-implant bone.
- MeSH
- fotoelektronová spektroskopie MeSH
- koroze MeSH
- kostní šrouby * škodlivé účinky MeSH
- lebka * patologie MeSH
- lidé MeSH
- nerezavějící ocel * chemie MeSH
- povrchové vlastnosti MeSH
- Ramanova spektroskopie MeSH
- rozhraní kost/implantát MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- železo chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
In this study, spherical or hexagonal NaYF4:Yb,Er nanoparticles (UCNPs) with sizes of 25 nm (S-UCNPs) and 120 nm (L-UCNPs) were synthesized by high-temperature coprecipitation and subsequently modified with three kinds of polymers. These included poly(ethylene glycol) (PEG) and poly(N,N-dimethylacrylamide-co-2-aminoethylacrylamide) [P(DMA-AEA)] terminated with an alendronate anchoring group, and poly(methyl vinyl ether-co-maleic acid) (PMVEMA). The internalization of nanoparticles by rat mesenchymal stem cells (rMSCs) and C6 cancer cells (rat glial tumor cell line) was visualized by electron microscopy and the cytotoxicity of the UCNPs and their leaches was measured by the real-time proliferation assay. The comet assay was used to determine the oxidative damage of the UCNPs. An in vivo study on mice determined the elimination route and potential accumulation of UCNPs in the body. The results showed that the L- and S-UCNPs were internalized into cells in the lumen of endosomes. The proliferation assay revealed that the L-UCNPs were less toxic than S-UCNPs. The viability of rMSCs incubated with particles decreased in the order S-UCNP@Ale-(PDMA-AEA) > S-UCNP@Ale-PEG > S-UCNPs > S-UCNP@PMVEMA. Similar results were obtained in C6 cells. The oxidative damage measured by the comet assay showed that neat L-UCNPs caused more oxidative damage to rMSCs than all coated UCNPs while no difference was observed in C6 cells. An in vivo study indicated that L-UCNPs were eliminated from the body via the hepatobiliary route; L-UCNP@Ale-PEG particles were almost eliminated from the liver 96 h after intravenous application. Pilot fluorescence imaging confirmed the limited in vivo detection capabilities of the nanoparticles.
- MeSH
- krysa rodu rattus MeSH
- mezenchymální kmenové buňky * metabolismus účinky léků cytologie MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nanočástice chemie MeSH
- oxidační stres účinky léků MeSH
- polyethylenglykoly chemie MeSH
- velikost částic MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The issue of bone volume loss is playing an increasing role in bone tissue engineering. Research has focused on studying the preparation and use of different types of human or xenogenic materials and their osteogenic properties. An alternative source for this purpose could be autologous extracted teeth. The simple preparation protocol, minimal immune response, and rapid organizing of the newly formed bone with optimal mechanical properties predispose autologous hard teeth tissues (HTTs) as a promising material suitable in the indication of augmentation of maxillary and mandible defects, comparable to other high-end augmentation materials. The aim of this study was to experimentally evaluate the osteogenic potential of ground native autologous HTTs prepared by different demineralization procedures, aimed at potentiating the osteoinductive and osteoconductive properties of their organic components. The results indicate that the most effective preparation process for HTT stimulation is the application of Cleanser for 10 min followed by exposure to 0.6 N HCl for 5 min with a wash in phosphate-buffered saline solution.
- Publikační typ
- časopisecké články MeSH