1,721,008 research outputs found
Varoni E, Tschon M, Palazzo B, Nitti P, Martini L, Rimondini L. Agarose gel as biomaterial or scaffold for implantation surgery: characterization, histological and histomorphometric study on soft tissue response.
No full textDental biomaterials and natural products represent two of the main growing
research fields, revealing plant-derived compounds may play a role not only as
nutraceuticals in affecting oral health, but also in improving physico-chemical properties of
biomaterials used in dentistry. Therefore, our aim was to collect all available data concerning
the utilization of plant polysaccharides, proteins and extracts rich in bioactive phytochemicals
in enhancing performance of dental biomaterials. Although compelling evidences are
suggestive of a great potential of plant products in promoting material-tissue/cell interface,
to date, only few authors have investigated their use in development of innovative dental
biomaterials. A small number of studies have reported plant extract-based titanium implant
coatings and periodontal regenerative materials. To the best of our knowledge, this review
is the first to deal with this topic, highlighting a general lack of research findings in an
interesting field which still needs to be investigate
Utilizzo di nuovi copolimeri iniettabili e biodegradabili a base di PLA/PGA nel trattamento di perdite di sostanza ossea.
No full textIn Vivo Preclinical Efficacy of a PDLLA/PGA Porous Copolymer for Dental Application
No full textThis study aimed to analyze surface morphology and physical-chemical properties of a copolymer of polylactic/polyglycolic acid (Fisiograft, Ghimas SpA, Casalecchio di Reno, Italy) by scanning electron microscopy (SEM), porosimetry, and rheological analysis. Then the material was implanted in vivo to test its efficacy at promoting bone healing and new bone formation in postextraction sockets. Under general anaesthesia, sockets were created in 12 minipigs and then randomly filled with the porous copolymer in SPONGE or GEL form and compared with commercial BioOss (Geistlich Biomaterials) and Biocoral (Inoteb, France). At 15, 30, and 60 days from surgery, the newly formed trabecular bone quality was evaluated by means of histology and histomorphometry. The SEM and rheological analyses performed on GEL showed a surface microporosity and a rheological shear thinning behavior, whereas the SPONGE porosimetric measurements revealed larger pores. At 15 days, the new bone regrowth was observed in all treated sockets but appeared immature, as the trabeculae were very dense and thin. At 30 days, GEL and SPONGE were degraded, and the sockets were filled with bone that, in terms of bone volume fraction, trabecular number, and separation, was not statistically different from normal bon
In vivo experimental study on bone regeneration in critical bone defects using an injectable biodegradable PLA/PGA copolymer
No full textObjectives. An assessment was done of the bone-healing rate after implantation of a polylactide/polyglycolide copolymer
(PLA-PGA) 50/50 dispersed in aqueous solution of PGA and dextran, used as bone substitutes in an animal model.
Study design. Two groups of 5 rabbits each were used. In both the femoral condyles, a critical size defect of 6 3 10 mm was
made. On the right side PLA/PGA was inserted; the left side remained empty. Thirty and 90 days after surgery the animals were
killed.
Results. Defects left unfilled showed no spontaneous healing after 30 and 90 days. Sites filled with experimental materials
showed new bone ranging between 11.46% and 76.82% after 30 days, and 75.98% and 95.34% after 90 days.
Histomorphometry showed an increase in bone maturation between day 30 and 90 in experimental sites. At day 90, no
statistical difference was seen as compared to normal bone.
Conclusion. PLA/PGA copolymer dispersed in hydrosoluble matrix seems to be suitable as osteoconductive material in critical
size defect
Feasibility of Electroporation in Bone and in the Surrounding Clinically Relevant Structures: A Preclinical Investigation
Full text linkSkeletal metastases are a common cause of severe morbidity, reduction in quality of life and often early mortality. Consequently, improvements in therapies are necessary. Electroporation uses electric energy to alter cancer cell membrane permeability and enhance the local uptake of chemotherapeutics, thus leading to local tumor control. The aim of this study was to investigate the feasibility and safety of delivering electric field protocols causing electroporation of healthy bone and structures of clinical relevance using small and large animal models. Reversible electroporation was used in the rabbit sciatic nerve by applying 2 series of 8 pulses 100ms long at 1000 V/cm. Irreversible electroporation was used in rabbit distal femur condyles and in sheep vertebral body by applying 120 pulses 100ms long at 1750 V/cm. Any effect on surrounding sensitive structures was investigated. Reversible electroporation of sciatic nerve was associated with transient foot functional deficit that completely recovered at 30 days. Irreversible electroporation removed cells from trabeculae in the femurs of rabbits and in the vertebral body of sheep. After irreversible protocol, histology and microtomography demonstrated that the trabecular structure was maintained, the presence of new bone marrow cells, osteoblasts, and mineral apposition characterized by new trabeculae thinner than controls (P =.005) and a significant reduction in the ablated areas (−225%, P =.0219). Spinal cord, vertebral pedicles and spinal nerves showed transient edema in the absence of functional or structural alterations. Collectively, these results show that electroporation can be safely applied to bone even in the proximity of neuronal structures
NATURAL AND SYNTHETIC POLYESTERS FOR MUSCULOSKELETAL TISSUE REPAIR: EXPERIMENTAL IN VITRO AND IN VIVO EVALUATIONS.
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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