Collagen Type I Biomaterials as Scaffolds for Bone Tissue Engineering

Collagen type I is the main organic constituent of the bone extracellular matrix and has been used for decades as scaffolding material in bone tissue engineering approaches when autografts are not feasible. Polymeric collagen can be easily isolated from various animal sources and can be processed in a great number of ways to manufacture biomaterials in the form of sponges, particles, or hydrogels, among others, for different applications. Despite its great biocompatibility and osteoconductivity, collagen type I also has some drawbacks, such as its high biodegradability, low mechanical strength, and lack of osteoinductive activity. Therefore, many attempts have been made to improve the collagen type I-based implants for bone tissue engineering. This review aims to summarize the current status of collagen type I as a biomaterial for bone tissue engineering, as well as to highlight some of the main efforts that have been made recently towards designing and producing collagen implants to improve bone regeneration.

Non-Collagen Protein in the Dentin Tissue – The Role in the Process of Dentinogenesis

Collagen forms the major organic constituent of human tooth dentin with non-collagen proteins and proteoglycans contributing for minor fragment. Studies involving the nature of non–collagen proteins are comparatively rarer than the other dentinal components. With this background the authors conducted the present study. To identify the specific and unspecific non-collagen proteins in the dentin. Samples of teeth tissue prepared using guanine hydrochloride in natrium acetate and then subjected to polyacrylamide gel electrophoresis. The samples were visualized using Coomassie Blue coloring technique. The pattern of electrophoresis of dentin fraction indicated large protein component. The mass spectrometric analysis results of the two gel parts confirmed the presence of dentin sialoprotein and bone sialoprotein in the dentin fraction. Difference in the molecular mass was evident between the two protien fractions. The authors suggest that since dentin sialoprotein is specific to dentin and not identified in any other tissue, it may be a unique constituent and may play a critical role in formation of dentin.

Svjetlosni oblici Vojina Bakića

Bakić’s cycle Luminous Forms marks a significant conceptual shift and radicalization of expression in relation to the pre-existing tradition in Croatian sculpture. At the same time, it corresponds to the movements in European sculpture of the 1960s at which time the visual language changed in order to match a dynamic construction of forms, where a sculptor leaves out the inner core and disintegrates it with more liberal combinations and sequencing of elements.Within the limits of his own range and scope, Bakić constantly manifested a number of overall coincidences with particular issues and ideas presentat a specific moment in the global artistic sphere, and he did this in a surprisingly intense and exciting way which was at the same time polemical, competitive and rooted in principles. He took an active part inthe radical changes in the visual, aesthetic, social and spiritual aspect of art of his time, including the issue of language and form as an optical phenomenon of light and movement. His work in the 1960s contains some other features which were always favoured by the modern movement such as technological innovation, a youthful spirit, a soupçon of subculture, emancipatory pretensions,dynamism, novel, fresh aesthetics… In his cycles, Bakić embodied faith in the future and the creation of new blueprints for the world, in a spontaneous and uninterrupted creativity, and in numerous modernstylistic modalities which he realized very successfully in the corresponding form, shape and iconography. Bakić was convinced that his sculpted object could be an organic, constituent and functional part of the architectural and urban structure, and hoped that architects and urban planners would begin to understandthe importance of a sculptor’s participation not only in the process of architectural and urban design itself, but also in the autonomous mediation of a sculptor in both of those fields.With regard to their expressive and material aspect, Luminous Forms fit relatively easily into the international domain of contemporary art and, most of all, confirm that Bakić is a sculptor who is adept at supple formswithin the context of innovations focusing on problemsolving becausethey are based on the idea that incessant innovation is necessary, as it is to be inclined towards experimental approach to art.