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The marine environment is believed to be the greatest treasure trove regarding availability of bioactive molecules and secondary metabolites from marine organisms. These untapped potential natural resources in the form of naturally derived polysaccharides such as chitin, chitosan, alginate, fucoidan, carrageenan and chondroitin sulfate are proven to be versatile biomaterials. Their superior structure and variability in their composition along with the mechanical, physicochemical and biological properties made them potent biomaterials in the field of biomedicine as pharmacological and drug delivery agents, as well as in regenerative medicine. Nanoformulations and 3D-scaffold designs of these biocompatible materials enabled significant advances in the field of molecular delivery and tissue engineering. Further, physical and chemical modifications to these biomaterials enhanced the therapeutic and regenerative capacity of biomolecules and stem cells in therapy, which are mostly under clinical investigations, and some are in clinical use. In recent years, there has been a tremendous rise in the use of these marine biomaterials (chitosan, fucoidan, alginate, biosilica, bio-ceramics etc.) as a replacement for synthetic materials in bone regenerative medicine. This chapter discusses the basic potent bio-functional properties, structural compatibility as scaffold materials and their applications in the multidisciplinary fields of molecular and clinical research. The latest biomaterial advances in the field of dental medicine and surgery for implantation are also discussed.

Biopolymers have been serving the mankind in various ways since long. Over the last few years, these polymers have found great demand in various domains which includes bio medicine, tissue engineering, bio sensor fabrications etc. because of their excellent bio compatibility. In this context, chitosan has found global attention due to its environmentally benign nature, biocompatibility, biodegradability, and ease of availability. In last one decade or so, extensive research in active biomaterials, like chitosan has led to the development of novel delivery systems for drugs, genes, and biomolecules; and regenerative medicine. Additionally, chitosan has also witnessed its usage in functionalization of biocompatible materials, nanoparticle (NP) synthesis, and immobilization of various bio-recognition elements (BREs) to form active bio-surfaces with great ease. Keeping these aspects in mind, we have written a comprehensive review which aims to acquaint its readers with the exceptional properties of chitosan and its usage in the domain of biomedicine, tissue engineering, and biosensor fabrication. Herein, we have briefly explained various aspects of direct utilization of chitosan and then presented vivid strategies towards formulation of chitosan based nanocomposites for biomedicine, tissue engineering, and biosensing applications.

A series of octanuclear p-cymene ruthenium and pentamethylcyclopentadienyl rhodium and iridium metalla-assemblies has been prepared from tetrapyridyl porphyrin (tpp) panels and the corresponding dinuclear clips, (η6-MeC6H4Pri)2Ru2(μ4-C6HRO4)Cl2 (R = C11H23) and (η5-C5Me5)2M2(μ4-C6HRO4)Cl2 (M = Rh, Ir). All complexes were isolated in good yield as their triflate salts, [(η6-MeC6H4Pri)8Ru8(μ4-tpp)2(μ4-C6HRO4)4][CF3SO3]8 (1), [(η5-C5Me5)8Rh8(μ4-tpp)2(μ4-C6HRO4)4][CF3SO3]8 (2) and [(η5-C5Me5)8Ir8(μ4-tpp)2(μ4-C6HRO4)4][CF3SO3]8 (3), and fully characterized by spectroscopic methods. The antiproliferative activity of the complexes was evaluated on the cancerous (MCF-7, B16 and A549) and non-cancerous (NIH 3T3) cell lines, showing in all cases IC50 values around 0.1 μM. Further biological studies suggest that apoptosis is induced by the complexes and that interaction with DNA can be in part responsible for the high cytotoxicity.

A significant number of clinical trials have been undertaken to explore the use of mesenchymal stem cells (MSCs) for the treatment of several diseases such as Crohn’s disease, diabetes, bone defects, myocardial infarction, stroke etc., Due to their efficiency in homing to the tissue injury sites, their differentiation potential, the capability to secrete a large amount of trophic factors and their immunomodulatory effects, MSCs are becoming increasingly popular and expected to be one of the promising therapeutic approaches. However, challenges associated with the isolation of pure MSC populations, their culture and expansion, specific phenotypic characterization, multi-potential differentiation and challenges of efficient transplantation limit their usage. The current strategies of cell-based therapies emphasize introducing beneficial genes, which will improve the therapeutic ability of MSCs and have better homing efficiency. The continuous improvement in gene transfer technologies has broad implications in stem cell biology. Although viral vectors are efficient vehicles for gene delivery, construction of viral vectors with desired genes, their safety and immunogenicity limit their use in clinical applications. We review current gene delivery approaches, including viral and plasmid vectors, for transfecting MSC with beneficial genes. The review also discusses the use of a few emerging technologies that could be used to improve the transfer/induction of desirable genes for cell therapy.

Stem cells, either neural [NSCs] or mesenchymal [MSCs], possess tremendous untapped potential for cell therapy. Unlike the NSCs, MSCs are multi-potent and they have high self-renewal capability and broad tissue distribution. Since they do not produce significant immune rejection on post-transplantation; they are better suited for cell-based therapies. However, several critical issues need to be addressed to maximize stem cell-derived therapeutic effects. The key factor affecting the therapeutic application of stem cells is exposure to hostile conditions in vivo such as oxidative stress, which results in considerably low survival rate of these cells at transplanted sites, thereby reducing the therapeutic efficiency. Such limitation has led scientists to design clinically relevant, innovative and multifaceted solutions including the use of nanobiomaterials. Use of cytocompatible nanobiomaterials holds great promise and has gained attention of researchers, worldwide. Various nanobiomaterials are being explored to increase the survival efficiency and direct differentiation of stem cells to generate tissue-specific cells for biomedical research and futuristic therapies. These materials have superior cytocompatability, mechanical, electrical, optical, catalytic and magnetic properties. Non-invasive visualization of the biological system has been developed using magnetic nanoparticles and magnetic resonance imaging [MRI] approaches. Apart from viral vectors, non-viral carriers such as DNA nano carriers, single stranded RNA nanoparticles, liposomes and carbon nanotubes/wires are being exploited for gene delivery into stem cells. This article reviews potential application of various biocompatible nanomaterials in stem cell research and development.