196,067 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
No full textSkeletal 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
Bone remodeling, humoral networks and smart biomaterial technology for osteoporosis.
No full textOne of the unfortunate sequelae of increased life expectancy is a growing number of age-related degenerative diseases, a prime example being osteoporosis. This form of metabolic bone disease and related co-morbidities consume tremendous resources and costs from a nation's health care system. Osteoporosis results from genetic, age-related, and hormone-dependent causes as well as a compendium of secondary pathophysiological states. The presence of osteoporosis as a comorbidity confers a significant negative prognostic element following orthopedic procedures. In vitro and in vivo studies of osteoporotic bone implicate microarchitectural bone rarefaction, microenvironmental and functional disturbance of osteoblast-osteoclast coupling, and abnormal tissue and signalling molecule repertoires, each having detrimental effects on the regenerative and osteointegration processes. This review explores the pathophysiology of bone remodeling from a macro- and micro- systems biology standpoint with a focus on cytokine interactions. Furthermore, therapeutic interventions exploiting vulnerable nodes in these physiological networks will be posited. One exciting development in this area is the use of novel biomaterials
Ablation of bone cells by electroporation
No full textShort intense electrical pulses transiently increase the permeability of the cell membrane, an effect known as electroporation. This can be combined with antiblastic drugs for ablation of tumours of the skin and subcutaneous tissue. The aim of this study was to test the efficacy of electroporation when applied to bone and to understand whether the presence of mineralised trabeculae would affect the capability of the electric field to porate the membrane of bone cells. Different levels of electrical field were applied to the femoral bone of rabbits. The field distribution and modelling were simulated by computer. Specimens of bone from treated and control rabbits were obtained for histology, histomorphometry and biomechanical testing. After seven days, the area of ablation had increased in line with the number of pulses and/or with the amplitude of the electrical field applied. The osteogenic activity in the ablated area had recovered by 30 days. Biomechanical testing showed structural integrity of the bone at both times. Electroporation using the appropriate combination of voltage and pulses induced ablation of bone cells without affecting the recovery of osteogenic activity. It can be an effective treatment in bone and when used in combination with drugs, an option for the treatment of metastases
Different doses of low–level laser irradiation modulate the in vitro response of osteoblast-like cells
No full textThe in vitro response of osteoblast-like cells to different doses of low–level laser irradiation is described
NATURAL AND SYNTHETIC POLYESTERS FOR MUSCULOSKELETAL TISSUE REPAIR: EXPERIMENTAL IN VITRO AND IN VIVO EVALUATIONS.
No full textBone remodeling, humoral networks and smart biomaterial technology for osteoporosis
No full textOne of the unfortunate sequelae of increased life expectancy is a growing number of age-related degenerative diseases, a prime example being osteoporosis. This form of metabolic bone disease and related co-morbidities consume tremendous resources and costs from a nation's health care system. Osteoporosis results from genetic, age-related, and hormone-dependent causes as well as a compendium of secondary pathophysiological states. The presence of osteoporosis as a comorbidity confers a significant negative prognostic element following orthopedic procedures. In vitro and in vivo studies of osteoporotic bone implicate microarchitectural bone rarefaction, microenvironmental and functional disturbance of osteoblast-osteoclast coupling, and abnormal tissue and signalling molecule repertoires, each having detrimental effects on the regenerative and osteointegration processes. This review explores the pathophysiology of bone remodeling from a macro- and micro- systems biology standpoint with a focus on cytokine interactions. Furthermore, therapeutic interventions exploiting vulnerable nodes in these physiological networks will be posited. One exciting development in this area is the use of novel biomaterials
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