История возникновения католической общины города Севастополя и строительство римско-католического костёла

Цель статьи – проследить этапы формирования римско-католической общины города Севастополя и историю строительства римско-католического костёла во имя Священномученника Климента Римского

Human adult, pediatric and microtia auricular cartilage harbor fibronectin-adhering progenitor cells with regenerative ear reconstruction potential

Remaining challenges in auricular cartilage tissue engineering include acquiring sufficient amounts of regeneration-competent cells and subsequent production of high-quality neocartilage. Progenitor cells are a resident subpopulation of native cartilage, displaying a high proliferative and cartilage-forming capacity, yet their potential for regenerative medicine is vastly understudied. In this study, human auricular cartilage progenitor cells were newly identified in healthy cartilage and, importantly, in microtia-impaired chondral remnants. Their cartilage repair potential was assessed via in vitro 3D culture upon encapsulation in a gelatin-based hydrogel, and subsequent biochemical, mechanical, and histological analyses. Auricular cartilage progenitor cells demonstrate a potent ability to proliferate without losing their multipotent differentiation ability and to produce cartilage-like matrix in 3D culture. As these cells can be easily obtained through a non-deforming biopsy of the healthy ear or from the otherwise redundant microtia remnant, they can provide an important solution for long-existing challenges in auricular cartilage tissue engineering

PTH decreases in vitro human cartilage regeneration without affecting hypertrophic differentiation

Regenerated cartilage formed after Autologous Chondrocyte Implantation may be of suboptimal quality due to postulated hypertrophic changes. Parathyroid hormone-related peptide, containing the parathyroid hormone sequence (PTHrP 1–34), enhances cartilage growth during development and inhibits hypertrophic differentiation of mesenchymal stromal cells (MSCs) and growth plate chondrocytes. This study aims to determine the possible anabolic and/or hypertrophic effect of PTH on human articular chondrocytes. Healthy human articular cartilage-derived chondrocytes (n = 6 donors) were cultured on type II collagen-coated transwells with/without 0.1 or 1.0 μM PTH from day 0, 9, or 21 until the end of culture (day 28). Extracellular matrix production, (pre)hypertrophy and PTH signaling were assessed by RT-qPCR and/or immunohistochemistry for collagen type I, II, X, RUNX2, MMP13, PTHR1 and IHH and by determining glycosaminoglycan production and DNA content. The Bern score assessed cartilage quality by histology. Regardless of the concentration and initiation of supplementation, PTH treatment significantly decreased DNA and glycosaminoglycan content and reduced the Bern score compared with controls. Type I collagen deposition was increased, whereas PTHR1 expression and type II collagen deposition were decreased by PTH supplementation. Expression of the (pre)hypertrophic markers MMP13, RUNX2, IHH and type X collagen were not affected by PTH. In conclusion, PTH supplementation to healthy human articular chondrocytes did not affect hypertrophic differentiation, but negatively influenced cartilage quality, the tissues’ extracellular matrix and cell content. Although PTH may be an effective inhibitor of hypertrophic differentiation in MSC-based cartilage repair, care may be warranted in applying accessory PTH treatment due to its effects on articular chondrocytes

PTH decreases in vitro human cartilage regeneration without affecting hypertrophic differentiation.

Regenerated cartilage formed after Autologous Chondrocyte Implantation may be of suboptimal quality due to postulated hypertrophic changes. Parathyroid hormone-related peptide, containing the parathyroid hormone sequence (PTHrP 1-34), enhances cartilage growth during development and inhibits hypertrophic differentiation of mesenchymal stromal cells (MSCs) and growth plate chondrocytes. This study aims to determine the possible anabolic and/or hypertrophic effect of PTH on human articular chondrocytes. Healthy human articular cartilage-derived chondrocytes (n = 6 donors) were cultured on type II collagen-coated transwells with/without 0.1 or 1.0 μM PTH from day 0, 9, or 21 until the end of culture (day 28). Extracellular matrix production, (pre)hypertrophy and PTH signaling were assessed by RT-qPCR and/or immunohistochemistry for collagen type I, II, X, RUNX2, MMP13, PTHR1 and IHH and by determining glycosaminoglycan production and DNA content. The Bern score assessed cartilage quality by histology. Regardless of the concentration and initiation of supplementation, PTH treatment significantly decreased DNA and glycosaminoglycan content and reduced the Bern score compared with controls. Type I collagen deposition was increased, whereas PTHR1 expression and type II collagen deposition were decreased by PTH supplementation. Expression of the (pre)hypertrophic markers MMP13, RUNX2, IHH and type X collagen were not affected by PTH. In conclusion, PTH supplementation to healthy human articular chondrocytes did not affect hypertrophic differentiation, but negatively influenced cartilage quality, the tissues' extracellular matrix and cell content. Although PTH may be an effective inhibitor of hypertrophic differentiation in MSC-based cartilage repair, care may be warranted in applying accessory PTH treatment due to its effects on articular chondrocytes

Comparing Hydrogels for Human Nucleus Pulposus Regeneration: Role of Osmolarity during Expansion

Hydrogels can facilitate nucleus pulposus (NP) regeneration, either for clinical application or research into mechanisms of regeneration. However, many different hydrogels and culture conditions for human degenerated NP have been employed, making literature data difficult to compare. Therefore, we compared six different hydrogels of natural polymers and investigated the role of serum in the medium and of osmolarity during expansion or redifferentiation i n an attempt to provide comparators for future studies. Human NP cells of Thompson grade III discs were cultured in alginate, agarose, fibrin, type II collagen, gelatin methacryloyl (gelMA), and hyaluronic acid-poly(ethylene glycol) hydrogels. Medium containing fetal bovine serum and a serum-free (SF) medium were compared in agarose, gelMA, and type II collagen hydrogels. Isolation and expansion of NP cells in low compared to high osmolarity medium were performed before culture in agarose and type II collagen hydrogels in media of varying osmolarity. NP cells in agarose produced the highest amounts of proteoglycans, followed by cells in type II collagen hydrogels. The absence of serum reduced the total amount of proteoglycans produced by the cells, although incorporation efficiency was higher in type II collagen hydrogels in the absence than in the presence of serum. Isolation and expansion of NP cells in high osmolarity medium improved proteoglycan production during culture in hydrogels, but variation in osmolarity during redifferentiation did not have any effect. Agarose hydrogels seem to be the best option for in vitro culture of human NP cells, but for clinical application, type II collagen hydrogels may be better because, as opposed to agarose, it degrades in time. Although culture in SF medium reduces the amount of proteoglycans produced during redifferentiation culture, isolating and expanding the cells in high osmolarity medium can largely compensate for this loss

Effects of non-enzymatic glycation on the micro- and nano-mechanics of articular cartilage

The mechanical properties of articular cartilage depend on the quality of its matrix, which consists of collagens and glycosaminoglycans (GAGs). The accumulation of advanced glycation end products (AGEs) can greatly affect the mechanics of cartilage. In the current study, we simulated the accumulation of AGEs by using L-threose to cross-link collagen molecules in the cartilage matrix (in vitro). The resulting changes in the mechanical properties (stiffness) of cartilage are then measured both at the micrometer-scale (using micro-indenter) and nanometer-scale (using indentation-type atomic force microscopy). Non-enzymatic cross-linking within the cartilage matrix was confirmed by the browning of L-threose-treated samples. We observed > 3 times increase in the micro-scale stiffness and up to 12-fold increase in the nano-scale stiffness of the glycated cartilage in the peak pertaining to the collagen fibers, which is caused by cartilage network embrittlement. At the molecular level, we found that besides the collagen component, the glycation process also influenced the GAG macromolecules. Comparing cartilage samples before and after L-threose treatment revealed that artificially induced-AGEs also decelerate in vitro degradation (likely via matrix metalloproteinases), observed at both micro- and nano-scales. The combined observations suggest that non-enzymatic glycation may play multiple roles in mechanochemical functioning of articular cartilage

Comparing Hydrogels for Human Nucleus Pulposus Regeneration: Role of Osmolarity during Expansion

Hydrogels can facilitate nucleus pulposus (NP) regeneration, either for clinical application or research into mechanisms of regeneration. However, many different hydrogels and culture conditions for human degenerated NP have been employed, making literature data difficult to compare. Therefore, we compared six different hydrogels of natural polymers and investigated the role of serum in the medium and of osmolarity during expansion or redifferentiation i n an attempt to provide comparators for future studies. Human NP cells of Thompson grade III discs were cultured in alginate, agarose, fibrin, type II collagen, gelatin methacryloyl (gelMA), and hyaluronic acid-poly(ethylene glycol) hydrogels. Medium containing fetal bovine serum and a serum-free (SF) medium were compared in agarose, gelMA, and type II collagen hydrogels. Isolation and expansion of NP cells in low compared to high osmolarity medium were performed before culture in agarose and type II collagen hydrogels in media of varying osmolarity. NP cells in agarose produced the highest amounts of proteoglycans, followed by cells in type II collagen hydrogels. The absence of serum reduced the total amount of proteoglycans produced by the cells, although incorporation efficiency was higher in type II collagen hydrogels in the absence than in the presence of serum. Isolation and expansion of NP cells in high osmolarity medium improved proteoglycan production during culture in hydrogels, but variation in osmolarity during redifferentiation did not have any effect. Agarose hydrogels seem to be the best option for in vitro culture of human NP cells, but for clinical application, type II collagen hydrogels may be better because, as opposed to agarose, it degrades in time. Although culture in SF medium reduces the amount of proteoglycans produced during redifferentiation culture, isolating and expanding the cells in high osmolarity medium can largely compensate for this loss

Orthotopic bone regeneration within 3D printed bioceramic scaffolds with region-dependent porosity gradients in an equine model

The clinical translation of three-dimensionally printed bioceramic scaffolds with tailored architectures holds great promise toward the regeneration of bone to heal critical-size defects. Herein, the long-term in vivo performance of printed hydrogel-ceramic composites made of methacrylatedoligocaprolactone-poloxamer and low-temperature self-setting calciumphosphates is assessed in a large animal model. Scaffolds printed with different internal architectures, displaying either a designed porosity gradient or a constant pore distribution, are implanted in equine tuber coxae critical size defects. Bone ingrowth is challenged and facilitated only from one direction via encasing the bioceramic in a polycaprolactone shell. After 7 months, total new bone volume and scaffold degradation are significantly greater in structures with constant porosity. Interestingly, gradient scaffolds show lower extent of remodeling and regeneration even in areas having the same porosity as the constant scaffolds. Low regeneration in distal regions from the interface with native bone impairs ossification in proximal regions of the construct, suggesting that anisotropic architectures modulate the cross-talk between distant cells within critical-size defects. The study provides key information on how engineered architectural patterns impact osteoregeneration in vivo, and also indicates the equine tuber coxae as promising orthotopic model for studying materials stimulating bone formation.La traducción clínica de andamios biocerámicos impresos tridimensionalmente con arquitecturas adaptadas es muy prometedora para la regeneración de hueso para curar defectos de tamaño crítico. En este caso, el rendimiento in vivo a largo plazo de los compuestos impresos de cerámica de hidrogel hechos de metacrilato-oligocaprolactona-poloxámero y fosfatos de calcio de baja temperatura que se fijan por sí mismos se evalúa en un modelo de animal grande. Se implantan andamios impresos con diferentes arquitecturas internas, que muestran un gradiente de porosidad diseñado o una distribución de poros constante, en los defectos de tamaño crítico del tubérculo coxae equino. El crecimiento óseo se desafía y se facilita sólo desde una dirección mediante el encapsulamiento de la biocerámica en una cáscara de policaprolactona. Después de 7 meses, el volumen total de hueso nuevo y la degradación del andamiaje son significativamente mayores en estructuras con porosidad constante. Curiosamente, los andamios con pendiente muestran un menor grado de remodelación y regeneración incluso en zonas que tienen la misma porosidad que los andamios constantes. La baja regeneración en las regiones distales de la interfaz con el hueso nativo perjudica la osificación en las regiones proximales de la construcción, lo que sugiere que las arquitecturas anisotrópicas modulan la diafonía entre las células distantes dentro de los defectos de tamaño crítico. El estudio proporciona información clave sobre la forma en que las pautas arquitectónicas de ingeniería repercuten en la osteoregeneración in vivo, y también indica que el tubérculo equino coxae es un modelo ortotópico prometedor para estudiar los materiales que estimulan la formación ósea.Universidad Nacional, Costa RicaEscuela de Medicina Veterinari

Effects of non-enzymatic glycation on the micro- and nano-mechanics of articular cartilage

The mechanical properties of articular cartilage depend on the quality of its matrix, which consists of collagens and glycosaminoglycans (GAGs). The accumulation of advanced glycation end products (AGEs) can greatly affect the mechanics of cartilage. In the current study, we simulated the accumulation of AGEs by using L-threose to cross-link collagen molecules in the cartilage matrix (in vitro). The resulting changes in the mechanical properties (stiffness) of cartilage are then measured both at the micrometer-scale (using micro-indenter) and nanometer-scale (using indentation-type atomic force microscopy). Non-enzymatic cross-linking within the cartilage matrix was confirmed by the browning of L-threose-treated samples. We observed > 3 times increase in the micro-scale stiffness and up to 12-fold increase in the nano-scale stiffness of the glycated cartilage in the peak pertaining to the collagen fibers, which is caused by cartilage network embrittlement. At the molecular level, we found that besides the collagen component, the glycation process also influenced the GAG macromolecules. Comparing cartilage samples before and after L-threose treatment revealed that artificially induced-AGEs also decelerate in vitro degradation (likely via matrix metalloproteinases), observed at both micro- and nano-scales. The combined observations suggest that non-enzymatic glycation may play multiple roles in mechanochemical functioning of articular cartilage