Brillouin-Raman microspectroscopy is presented as an innovative label-free all-optical investigation approachable to characterize the chemical composition and the mechanical properties of human ...tissues at micrometric resolution. Brillouin maps unveil mechanical heterogeneities in a human femoral diaphysis, showing a ubiquitous co-existence of hard and soft components, even in the most compact sections. The novel correlative analysis of Brillouin and Raman maps shows that the relative intensity of Brillouin peaks is a good proxy for the fraction of mineralized fibers and that the stiffness (longitudinal elastic modulus) of the hard component is linearly dependent on the hydroxyapatite concentration. For the soft component, a gradient of composition is found, ranging from an abundance of proteins in the more compact, external, bone to abundance of lipids, carotenoids, and heme groups approaching the trabecular, inner, part of the diaphysis. This work unveils the strong potential of correlative mechano-chemical characterization of human tissues at a micrometric resolution for both fundamental and translational research.
Bone has a sophisticated architecture characterized by a hierarchical organization, starting at the sub-micrometre level. Thus, the analysis of the mechanical and structural properties of bone at ...this scale is essential to understand the relationship between its physiology, physical properties and chemical composition. Here, we unveil the potential of Brillouin-Raman microspectroscopy (BRaMS), an emerging correlative optical approach that can simultaneously assess bone mechanics and chemistry with micrometric resolution. Correlative hyperspectral imaging, performed on a human diaphyseal ring, reveals a complex microarchitecture that is reflected in extremely rich and informative spectra. An innovative method for mechanical properties analysis is proposed, mapping the intermixing of soft and hard tissue areas and revealing the coexistence of regions involved in remodelling processes, nutrient transportation and structural support. The mineralized regions appear elastically inhomogeneous, resembling the pattern of the osteons' lamellae, while Raman and energy-dispersive X-ray images through scanning electron microscopy show an overall uniform distribution of the mineral content, suggesting that other structural factors are responsible for lamellar micromechanical heterogeneity. These results, besides giving an important insight into cortical bone tissue properties, highlight the potential of BRaMS to access the origin of anisotropic mechanical properties, which are almost ubiquitous in other biological tissues.
Brillouin micro-spectroscopy is applied for investigating the mechanical properties of bone and cartilage tissues of a human femoral head. Distinctive mechanical properties of the cartilage surface, ...subchondral and trabecular bone are reported, with marked heterogeneities at both micrometric and millimetric length scales. A ubiquitous soft component is reported for the first time, characterized by a longitudinal modulus of about 4.3 GPa, possibly related to the amorphous phase of the bone. This phase is mixed, at micrometric scales, with a harder component, ascribed to mineralized collagen fibrils, characterized by a longitudinal modulus ranging between 16 and 25 GPa.
Abstract Background Nonunion is a major orthopaedic concern because of treatment difficulty, high costs and devastating effects on the patients’ life quality. Therefore, there is interest in the use ...of bone substitutes and cell-based strategies to augment fracture repair. We aimed to verify if Platelet Rich Fibrin (PRF) added with bone marrow stromal cells (BMSC) was able to improve the reparative process in the aseptic nonunion, and to establish whether it was worthwhile with atrophic nonunion. The primary outcome was radiological union. As secondary endpoint, the healing time was assessed, and the radiological consolidation grade at each follow-up. Methods We identified 113 subjects with tibia or femur nonunion and retrospectively created two groups. Group A was constituted by 56 subjects who underwent the standard procedure, i.e. Judet decortication with/out internal fixation devices, and opposite cortical homoplastic stick. In 57 patients, the standard procedure was modified by adding PRF and BMSC carried by homologous lyophilised bone chips (group B). The same surgeon performed all the operations. To our knowledge, no data are reported in the literature about such application. Since a “gold standard” for healing quantification does not exist, a new scoring radiological system was applied, at 1.5, 3, 6, 12 and 24 months after treatment. Results At the final 24-month follow-up, the radiological union percentage was 94,12 in group B and 95,12% in group A. A decreased healing time was demonstrated in the presence of PRF/BMSC in comparison with the standard procedure. When we compared the radiological scores at each follow-up, we found that the PRF/BMSC combination significantly improved the consolidation grade at 1.5-, 3- and 6-month follow-up in femurs and at 1.5-month follow-up in tibiae. Furthermore, an improved consolidation grade was demonstrated in the atrophic subjects treated with adjuvants compared to atrophic patients treated with the standard procedure at 1.5-month follow-up. Conclusions This study supports the concept that the use of PRF/BMSC, during the standard procedure, is effective in shortening nonunion healing time. It could allow an early mobilization of patients, minimizing suffering, and could be an effective tool to reduce the health-care costs resulting from this issue. Level of evidence Therapeutic level III.
We studied a set of common breeding birds living in a heterogeneous oak wood mosaic of Apennines (central Italy) where a wind farm occurred. Aim to assess differences in composition and structure ...between a treatment area (with wind farm turbines) and a control area (without wind farm turbines). We did not observe differences at assemblage (uni-and bi-variate metrics of diversity: mean species richness, Shannon–Wiener diversity index, evenness, Whittaker βw index and diversity/dominance diagrams), guild and species level (relative frequencies). The limited habitat perforation and dissection induced by wind farm turbines and service roads (10% in area) and the consequent changes in spatial heterogeneity and level of anthropogenic disturbance (induced by a higher motor-car and people frequentation) did not seem to affect the breeding bird communities in oak mosaics, as supported also by the diversity/dominance analysis. However, our preliminary conclusions are limited only to the indirect impact on common breeding bird species and are not related on to possible direct impacts deriving from wind farm facilities and related infrastructures (e.g., direct impact for collision). Moreover, further research is necessary to detect possible higher thresholds in habitat perforation that may induce changes in breeding bird assemblages.
The efficacy of clodronate to reduce bone loss around uncemented stems after total hip arthroplasty (THA) was evaluated. Ninety-one patients operated with uncemented THA were randomized to receive ...either intramuscular clodronate at a dose of 100 mg weekly for 12 months or no treatment. Periprosthetic and contralateral bone mineral density (BMD) scans were performed and biochemical markers of bone turnover measured at baseline and at 3, 6, and 12 months. At month 12, with the exception of Gruen zones 4 and 5, patients treated with clodronate showed less bone loss at all zones, reaching statistical significance (
P
< 0.05) in Gruen zones 2 and 6 (difference of 6.6 and 5.9%, respectively). Analysis of data according to gender revealed sex-related differences in bone loss and efficacy of treatment. After 12 months, the difference in bone loss between treated and untreated women in five out of seven Gruen zones ranged from 6.2 to 13.3% (SS at zones 2 and 6), whereas comparison between treated and untreated men showed no BMD differences in all zones (
P
> 0.05). Median percent changes in serum levels of markers of bone metabolism by gender were consistent with BMD changes. A 1-year treatment with intramuscular clodronate determined a significant reduction of bone loss after THA. This was mainly attributed to its greater efficacy in the female population, which is at higher risk for bone loss. This observation suggests the need for the characterization of high-risk subjects as potential candidates for prevention strategies.
Autologous chondrocyte implantation (ACI) is a cell-based treatment that can be used to regenerate chondral defects. European legislation specifically classifies such produced chondrocytes as ..."medicinal for advanced cell therapy" that have to be manufactured in pharmaceutical factories according to specific rules, named Good Manufacturing Practices (GMPs). One main requirement of cell manipulation in advanced therapy is to prevent the risk of any contamination.
The aim of this study was to verify if chondrocyte cultures suitable for ACI were free of cross-contamination by means of DNA profiling techniques.
Cell cultures were carried on in a Hospital Cell Factory in compliance with European current Good Manufacturing Practices. DNA profiling, by means of Short Tandem Repeats and miniShort Tandem Repeats analyses, was performed on expanded chondrocytes and their related control blood samples. Mitochondrial DNA was analysed to further confirm the results and to evaluate possible mutations occurred in the samples.
Our findings demonstrated the absence of cross-contamination between chondrocyte cultures and, thus, their identity maintenance until the end of the manipulation.
DNA profiling technique can be a suitable test for quality control not only for chondrocyte manipulation, but for cell therapy in general.
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