Search

Silicon-based materials present a high potential for dental implant applications, since silicon has been proven necessary for the correct bone formation in animals and humans. Notably, the addition of silicon is effective to enhance the bioactivity of hydroxyapatite and other biomaterials. The present work aims to expand the knowledge of the role exerted by hydrogen in the biological interaction of silicon-based materials, comparing two hydrogenated amorphous silicon coatings, with different hydrogen content, as means to enhance soft tissue cell adhesion. To accomplish this task, the films were produced by plasma enhanced chemical vapor deposition (PECVD) on titanium substrates and their surface composition and hydrogen content were analyzed by means of X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectrophotometry (FTIR) respectively. The surface energy and roughness were measured through optical contact angle analysis (OCA) and high-resolution mechanical profilometry respectively. Coated surfaces showed a slightly lower roughness, compared to bare titanium samples, regardless of the hydrogen content. The early cell responses of human keratinocytes and fibroblasts were tested on the above mentioned surface modifications, in terms of cell adhesion, viability and morphometrical assessment. Films with lower hydrogen content were endowed with a surface energy comparable to the titanium surfaces. Films with higher hydrogen incorporation displayed a lower surface oxidation and a considerably lower surface energy, compared to the less hydrogenated samples. As regards mean cell area and focal adhesion density, both a-Si coatings influenced fibroblasts, but had no significant effects on keratinocytes. On the contrary, hydrogen-rich films increased manifolds the adhesion and viability of keratinocytes, but not of fibroblasts, suggesting a selective biological effect on these cells. [ABSTRACT FROM AUTHOR]

Plasma surface activation and plasma polymers deposition are promising technologies capable to modulate biologically relevant surface features of biomaterials. The purpose of this study was to evaluate the biological effects of two different surface modifications, i.e. amine (NH 2 -Ti) and carboxylic/esteric (COOH/R-Ti) functionalities obtained from 3-aminopropyltriethoxysilane (3-APTES) and methylmethacrylate (MMA) precursors, respectively, through an atmospheric plasma jet RF-APPJ portable equipment. The coatings were characterized by Scanning Electron Microscopy, FT-IR spectroscopy, XPS and surface energy calculations. Stability in water and after UV sterilization were also verified. The pre-osteoblastic murine cell line MC3T3-E1 was used to perform the in-vitro tests. The treated samples showed a higher quantity of adsorbed proteins and improved osteoblast cells adhesion on the surfaces compared to the pristine titanium, in particular the COOH/R-Ti led to a nearly two-fold improvement. Cell proliferation on coated samples was initially (at 24 h) lower than on titanium control, while, at 48 h, COOH/R-Ti reached the proliferation rate of pristine titanium. Cells grown on NH 2 -Ti were more tapered and elongated in shape with lower areas than on COOH/R-Ti enriched surfaces. Finally, NH 2 -Ti significantly enhanced osteocalcin production, starting from 14 days, while COOH/R-Ti had this effect only from 21 days. Notably, NH 2 -Ti was more efficient than COOH/R-Ti at 21 days. The amine functionality elicited the most relevant osteogenic effect in terms of osteocalcin expression, thus establishing an interesting correlation between early cell morphology and later differentiation stages. Taken together, these data encourage the use of the functionalization procedures here reported in further studies. [ABSTRACT FROM AUTHOR]

Bone is the second most manipulated tissue after blood. Adipose-derived stem cells (ASCs) may become a convenient source of MSC for bone regenerative protocols. Surprisingly, little is known about the most significant biomolecules these cells produce and release after being osteoinduced. Therefore, the present study aimed at dosing 13 candidates chosen among the most representative cytokines, chemokines, and growth factors within the conditioned media of osteodifferentiated and undifferentiated ASCs. Two acknowledged osteoblastic cell models, that is, MG-63 and SaOs-2 cells, were compared. Notably, IL-6, IL-8, MCP-1, and VEGF were highly produced and detectable in ASCs. In addition, while IL-6 and IL-8 seemed to be significantly induced by the osteogenic medium, no such effect was seen for MCP-1 and VEGF. Overall SaOS-2 had a poor expression profile, which may be consistent with the more differentiated phenotype of SaOs-2 compared to ASCs and MG-63. Instead, in maintaining medium, MG-63 displayed a very rich production of IL-12, MCP-1, IP-10, and VEGF, which were significantly reduced in osteogenic conditions, with the only exception of MCP-1. The high expression of MCP-1 and VEGF, even after the osteogenic commitment, may support the usage of ASCs in bone regenerative protocols by recruiting both osteoblasts and osteoclasts of the host. [ABSTRACT FROM AUTHOR]

Silicon nitride (SiN) has been introduced clinically as an orthopedic biomaterial for interbody fusion devices and in joint replacements. However, the production of complex shapes through conventional mechanical machining is difficult and expensive and limits interesting applications. Thus, several electrically conductive reinforcements to the SiN matrix, like TiN, have been proposed, generating composites suitable to be wrought by electrical discharge machining (EDM). In this study, SiN-TiN with high strength, low density, and good electric conductivity wrought by EDM was studied. The role of surface finishing was investigated comparing the interface generated during the EDM process to that resulting from further polishing. The different topographical features were assessed by electron microscopy, energy dispersive X-ray spectrometry, and profilometry. Surface wettability was also determined based on the measurement of the OCA of water and diiodomethane. The biological responses induced in MC3T3 cells, a widely diffused osteoblast model, were correlated with the surface pattern. The unpolished samples could promote better cell viability, with a more relevant effect on the cytoskeleton arrangement as highlighted by numerous cytoplasmic extensions and filopodia-like structures and the high number of focal adhesions, while MC3T3 cells grown on polished SiN-TiN specimens displayed a flat morphology. In addition, the unpolished SiN-TiN increased osteocalcin production and calcium deposition. Taken together, these data support the biocompatibility and in vitro osteogenic properties of the electroconductive SiN-TiN investigated. Further in vivo studies are required to explore the possible use of bone implants directly obtained by EDM. [ABSTRACT FROM AUTHOR]

During wound healing, biologically active molecules are released from platelets. The rationale of using platelet-rich plasma (PRP) relies on the concentration of bioactive molecules and subsequent delivery to healing sites. These bioactive molecules have been seldom simultaneously quantified within the same PRP preparation. In the present study, the flexible Bio-Plex system was employed to assess the concentration of a large range of cytokines, chemokines, and growth factors in 16 healthy volunteers so as to determine whether significant baseline differences may be found. Besides IL-1b, IL-1ra, IL-4, IL-6, IL-8, IL-12, IL-13, IL-17, INF-γ, TNF-α, MCP-1, MIP-1a, RANTES, bFGF, PDGF, and VEGF that were already quantified elsewhere, the authors reported also on the presence of IL-2, IL-5, IL-7, IL-9, IL-10, IL-15 G-CSF, GM-CSF, Eotaxin, CXCL10 chemokine (IP-10), and MIP 1b. Among the most interesting results, it is convenient to mention the high concentrations of the HIV-suppressive and inflammatory cytokine RANTES and a statistically significant difference between males and females in the content of PDGF-BB. These data are consistent with previous reports pointing out that gender, diet, and test system affect the results of platelet function in healthy subjects, but seem contradictory when compared to other quantification assays in serum and plasma. The inconsistencies affecting the experimental results found in literature, along with the variability found in the content of bioactive molecules, urge further research, hopefully in form of randomized controlled clinical trials, in order to find definitive evidence of the efficacy of PRP treatment in various pathologic and regenerative conditions. [ABSTRACT FROM PUBLISHER]

Products of different origin, time of collection, and activities fall under the general term of colostrum and, therefore, great variability in composition as well as in the concentration of its components has been reported in the literature. In the present study, we describe the standardization of a bovine colostrum derivative and the characterization of its bioactive components. Evaluation of the most representative agents (lactoferrin, transferrin, IL-2, IFN-γ, tumor necrosis factor, IgG, and IgA) showed that a marked decrease in active components occurs after the first few hours. Bovine colostrum was, therefore, collected up to the fifth hour after delivery from Holstein cows, in the presence of preservatives, and immediately frozen. A protocol of centrifugation, filtration, and lyophilization was then applied to pools of colostrum from at least 30 cows to obtain a stable, sterile, standardized product. Preservatives were removed by dialysis. Evaluation of the active biological components of colostrum showed that the final product of colostrums contained significant and reproducible amounts of bioactive factors, including cytokines, immunomodulating factors, growth factors, and immunoglobulins. The final product appeared, therefore, as a sterile, pyrogen-free, standardized derivative of bovine colostrum with a high concentration of bioactive components. [ABSTRACT FROM AUTHOR]

Abstract: In this work we present some results about the low temperature, plasma-assisted growth of silicon–oxygen amorphous thin film alloys (a-SiO x ) on different types of dental materials used for the fabrication of dental prostheses. The a-SiO x films were grown at substrate temperatures lower than 70 °C by a PECVD deposition system using silane (SiH4) and nitrous oxide (N2O) as precursor gases. The chemical bonding structure of the films was investigated by Fourier transform infra-red spectroscopy (FTIR), while the morphological characteristics of the dental materials were analyzed before and after the coating deposition by means of high-resolution mechanical profilometry. The surface energy of dental materials was estimated before and after the coating process by contact angle measurements, revealing that the coating produced a considerable change of surface energy in all the tested samples, evidenced by a contact angle reduction from more than 90° to less than 10°. Some tests were also performed to estimate the effect of the coating on the bacterial adhesion properties, revealing that the a-SiO x coatings show some effectiveness in reducing the bacterial adhesion on the dental materials surface. [Copyright &y& Elsevier]

Purpose: This study aims to assess the effectiveness of Microfragmented Autologous Fat Tissue (MFAT) treatment for knee osteoarthritis and to investigate whether patients' pre-treatment clinical condition, such as synovitis, correlates with clinical outcomes, to identify potential predicting factors for the success or failure of the treatment. Methods: In this prospective Cohort Study Level II multicentric trial, consecutive patients with a diagnosis of early/mild osteoarthritis and failure of previous conservative measures were enrolled to undergo diagnostic arthroscopy and a single MFAT injection. Patients were assessed with repeated scoring systems at baseline, 6 months, and 12 months after surgery. The demographic features, the arthroscopic findings, the immunophenotype of injected tissue and the histologic examination of synovia of failed patients were analyzed. Results: Data from 91 patients showed a significant improvement in Lysholm, WOMAC scores at 1-year follow-up (p < 0.001). A significant decrease in VAS score was observed, while a significant improvement of measured flexion angle was registered at 1 year (p < 0.001). No major complications were reported. Age and synovitis were identified as significant factors influencing the clinical outcome (p < 0.05). Body mass index, previous or concomitant procedures, and specific cartilage defects had no influence. The mean number of injected adipose tissue-derived mesenchymal stem cells seem not to correlate with the clinical outcome. Conclusion: MFAT is effective in reducing pain when used with a single dose injection in early/mild OA of the knee, without major complications. Age over 60 and synovitis may be predictive for persistent pain at one year and should be considered before indications. [ABSTRACT FROM AUTHOR]

Highlights: [•] ZTA and ATZ were functionalized with laminin-1 and laminin-5. [•] XPS and AFM were used to characterize the functionalized surfaces. [•] In vitro bioactivity was determined by phosphorylation of major kinases. [•] An excellent cellular activation was highlighted for ATZ/Ln-5 and ZTA/Ln-1. [Copyright &y& Elsevier]

Bone plays several physiological functions and is the second most commonly transplanted tissue after blood. Since the treatment of large bone defects is still unsatisfactory, researchers have endeavoured to obtain scaffolds able to release growth and differentiation factors for mesenchymal stem cells, osteoblasts and endothelial cells in order to obtain faster mineralization and prompt a reliable vascularization. Nowadays, the application of osteoblastic cultures spans from cell physiology and pharmacology to cytocompatibility measurement and osteogenic potential evaluation of novel biomaterials. To overcome the simple traditional monocultures in vitro, co-cultures of osteogenic and vasculogenic precursors were introduced with very interesting results. Increasingly complex culture systems have been developed, where cells are seeded on proper scaffolds and stimulated so as to mimic the physiological conditions more accurately. These bioreactors aim at enabling bone regeneration by incorporating different cells types into bio-inspired materials within a surveilled habitat. This review is focused on the most recent developments in the organomimetic cultures of osteoblasts and vascular endothelial cells for bone tissue engineering. [ABSTRACT FROM AUTHOR]