Nature is constantly surprising us with examples of outstanding features, being them of chemical, morphological or biological nature, inspiring scientists towards innovative routes. In particular, marine environment has been receiving growing attention and the advent of marine (blue) biotechnology is strongly contributing to it, in much extent approaching its health (red) counterpart, fostering new therapeutic proposals. Several marine biomaterials are currently being proposed for the sustained delivery of bioactive compounds, often triggered by external stimuli, which may be combined with polymeric matrices for cell culture, on the development of the so-called functional biopolymers. Chitosan and alginate are the most common examples, but other marine origin materials start to find their place, namely the sulfated polysaccharides from seaweeds (p.e. carrageenans) and collagens extracted from marine organisms. Nevertheless, the challenges faced are still high: one benefits from the knowledge acquired with other biopolymers and from keen scientists, but thrilling examples of marine functional biomaterials for cartilage regeneration are still scarce, particularly when considering their in-vivo performance. Those are needed to act as landmarks and inspiration for further developments, namely to instigate the investment of the private biomedical industry to take them into clinics. Current pathologies of articular cartilage are daring us to find ultimate therapeutic solutions and we expect to contribute to the needed discussion with the present chapter, pointing examples of marine functional biomaterials and proposing possible paths to be followed.

[Excerto] O Instituto de Investigação em Biomateriais, Biodegradáveis e Biomiméticos, I3Bs, é a mais recente Unidade Orgânica da Universidade do Minho, surgindo em março de 2018, tendo sido uma das primeiras Unidades Orgânicas de Investigação criada no âmbito do RJIES (2007) em Universidades públicas Portuguesas. No entanto, a sua história tem origem em 1999, com a criação do Grupo de Investigação 3B’s, dedicado à investigação científica em biomateriais, engenharia de tecidos, medicina regenerativa e células estaminais. Nessa altura, um conjunto de jovens docentes e investigadores corporizava projetos de investigação em materiais poliméricos, cerâmicos e compósitos para aplicação biomédica, com aposta forte nas colaborações internacionais e multidisciplinares e olhando para a Natureza como fonte de inspiração para o seu desenvolvimento. A consolidação deste grupo de investigação como um dos principais atores da sua área científica a nível mundial e, do ponto de vista institucional, a evolução até Unidade Orgânica, demonstram o acerto dessa estratégia, que continua a governar a sua ação. [...]

Introduction Nature has been since ever the inspiration driving mankind for the development of amazing systems, materials, constructions, devices, etc. Marine environment is not exception and the technological developments allowing the access to deeper locations and organisms are opening even more that gate to a new dimension of knowledge. One of the fields where marine organisms are acting stimulating the imagination of mankind is health, fostering the development of innovative pharmaceuticals and cosmetics, as well as new biomedical systems [1]. In this presentation, the authors will address the efforts that are being made by 3B’s Research Group on the development of marine inspired biomaterials towards tissue regeneration. Materials and Methods Polymer extraction Collagen has been extracted from several fish skins by acetic acid extraction, complemented by enzymatic treatment by using pepsin. Polysaccharides have been extracted from different marine sources, namely from algae (sulfated polysaccharides, typically using hot water and precipitation with organic solvents) and from squid pens (chitin, further converted into chitosan, by NaHO treatments). Development of biomaterials Porous structures have been developed following different processing techniques, from freeze-drying (chitosan and collagen) to particle agglomeration (chitosan and composites with nanohydroxiapatite) and rapid prototyping (carrageenans). Their morphological properties were assessed by SEM and micro-computed tomography (μCT); mechanical properties evaluated by compression tests; biological performance has been tested with chondrocyte-like cell line ATDC5 (chitosan and collagen scaffolds) or adipose derived stem cells, ASCs (chitosan scaffolds). Additionally, natural collagenous porous structures were obtained by decellularization of marine sponges, together with extraction of toxic compounds. Results Several marine origin polymers were used to produce porous structures envisaged as scaffolds for tissue engineering approaches. Squid chitosan scaffolds were produced by freeze-drying, in which ATDC5 cells adhered and proliferated. Squid chitosan scaffolds were produced also by particle aggregation, including as composites with nanohydroxiapatite, in which ASCs were successfully cultured up to 7 days. Carrageenan structures were produced by rapid prototyping, revealing to be non-cytotoxic to rat lung fibroblasts. Marine collagen structures have been produced by freeze-drying and crosslinked with genipin under dense CO2, obtaining porous structures stable in culture medium, in which ATDC5 cells were successfully cultured. Additionally, the collagenous structure of marine sponges was also assessed as nature made scaffolds, revealing a non toxic structure able to support culture of osteoblast-like cell line. Discussion and Conclusions Several porous structures have been produced based on marine origin polymers, and successfully used as 3D support for cell culture. Their use as scaffolds is enhancing the potential of marine resources and inspiration for tissue regeneration approaches. References 1. TH Silva,…, RL Reis, Int Mater Rev 57 (2012) 276-306. Acknowledgments Funding is acknowledged from projects IBEROMARE (POCTEP), MARMED (Atlantic Area), NOVOMAR (POCTEP), POLARIS (FP7) and SPECIAL (FP7).

Marine organisms are constituted by materials with a vast range of properties and characteristics that may justify their potential application within the biomedical field. Moreover, assuring the sustainable exploitation of natural marine resources, the valorisation of residues from marine origin, like those obtained from food processing, constitutes a highly interesting platform for development of novel biomaterials, with both economic and environmental benefits. In this perspective, an increasing number of different types of compounds are being isolated from aquatic organisms and transformed into profitable products for health applications, including controlled drug delivery and tissue engineering devices. This report reviews the work that is being developed on the isolation and characterisation of some polysaccharides, proteins, glycosaminoglycans and ceramics from marine raw materials. Emphasis is given to agar, alginates, carrageenans, chitin and chitosan, among other polysaccharides, collagen, glycosaminoglycans such as chondroitin sulphate, heparin and hyaluronic acid, calcium phosphorous compounds and biosilica. Finally, this report ends by reviewing the application of the previously mentioned materials on specific biomedical applications, in particular their participation on the development of controlled drug delivery systems and tissue engineering scaffolds.

Biomedical field is constantly requesting for new biomaterials, with innovative properties. Natural polymers appear as materials of election for this goal due to their biocompatibility and biodegradability. In particular, materials found in marine environment are of great interest since the chemical and biological diversity found in this environment is almost uncountable and continuously growing with the research in deeper waters. Moreover, there is also a slower risk of these materials to pose illnesses to humans. In particular, sulfated polysaccharides can be found in marine environment, in different algae species. These polysaccharides don’t have equivalent in the terrestrial plants and resembles the chemical and biological properties of mammalian glycosaminoglycans. In this perspective, are receiving growing interest for application on health-related fields. On this review, we will focus on the biomedical applications of marine algae sulfated polymers, in particular on the development of innovative systems for tissue engineering and drug delivery approaches.

Collagens are the most abundant high molecular weight proteins in both invertebrate and vertebrate organisms, including mammals, and possess mainly a structural role, existing different types according with their specific organization in distinct tissues. From this, they have been elected as one of the key biological materials in tissue regeneration approaches. Also, industry is constantly searching for new natural sources of collagen and upgraded methodologies for their production. The most common sources are from bovine and porcine origin, but other ways are making their route, such as recombinant production, but also extraction from marine organisms like fish. Different organisms have been proposed and explored for collagen extraction, allowing the sustainable production of different types of collagens, with properties depending on the kind of organism (and their natural environment) and extraction methodology. Such variety of collagen properties has been further investigated in different ways to render a wide range of applications. The present review aims to shed some light on the contribution of marine collagens for the scientific and technological development of this sector, stressing the opportunities and challenges that they are and most probably will be facing to assume a role as an alternative source for industrial exploitation.

São Simão’s Brazilian kaolinite has been treated with titanium(IV) isopropoxide and cobalt(II) tetracarboxymetallophthalocyanine under different conditions (acidic or basic), leading, after drying at 100 ºC, to new titania-doped cobalt(II)-metallophthalocyanine/kaolinite solids. These solids were characterized by chemical analysis, powder X-ray diffraction, Fourier transform infrared spectroscopy, thermal analyses and nitrogen adsorption. No significant changes were observed by diffractometry, but the specific surface area depended of the synthetic route followed. The ability of these solids for photodegradation of trimethoprim, caffeine and prometryn was evaluated. The photodegradation was followed via mass spectrometry and UV-Vis absorption spectroscopy. The presence of photodegradation by-products was verified in all cases. All the photocatalysts showed high photodegradation rate against prometryn, trimethoprim and caffeine, the degradation efficiencies were 54, 30 and 90%, respectively, when using the heterogeneous photocatalysts. Comparison with commercial TiO2 (Degusa®) proved that the synthesized photocatalyst based on kaolinite present higher degradation rate than isolated titanium dioxide.

[Excerpt] Collagen is the main fibrous structural protein in the extracellular matrix and connective tissue of animals. It is a primary building block of bones, tendons, skin, hair, nails, cartilage, and all joints in the body. It is also considered a "glue" that holds the body together. In this regard, it receives great attention in healthcare and wellbeing, both as a functional ingredient in different formulations and as a component of several products, such as medical devices and pharmaceutical systems.