Introduction to Bioinspired Nanomaterials

Nanomaterials (NMs) developed using biomolecules display numerous advantages which attract the science community to explore them for a wide range of applications. In this line, bio-scaffolds are studied as templates to form nano-bio heterojunctions in the nano confined materials. With the high flexibility of biomediated NMs, it is possible to develop desired size and shape selective NMs. Such bio-based NMs have great benefits in wide areas including catalysis, sensors and energy related applications particularly, electrocatalysis, supercapacitor, batteries etc. The viability of bio-scaffolds in developing metal superstructures makes them better choice in the medicinal fields. This book chapter mainly focused on the advantageous and challenges of bioinspired NMs in the medicinal field, particularly in drug delivery systems. Moreover, the synthetic methods such as enzyme catalyzed wet-chemical route, photo-irradiation and incubation methods were also discussed in detail. Also, this chapter gives a better understanding to the readers about the development of new nano-bio heterojunctions for medicine, energy and environmental fields. Moreover, the morphological features of nano-bio interactions at nanoscale level show predominant activity particularly in Surface Enhanced Raman Scattering (SERS) and sensor applications. With the knowledge gained from this chapter, in futuristic, one can go for the development of new metal nanostructures with different bio-scaffolds such as microorganisms, viruses, DNA and protein to mainstream applications for the medicinal fields.

Bioinspired Nanomaterials for Drug Delivery

Over the preceding few decades therapeutic/drug delivery systems were explored and investigated as a tactic to advance the efficiency and safety of therapeutic agents for various biomedical applications. Nano-engineering on the various biomaterials are reported and are under investigation to enhance the pharmacokinetics and pharmacodynamics of many drugs, with proven enhancements in terms of objective facility, therapeutic efficacy, reduction in dosing frequency and associated drug side effects. Bioinspired materials from various sources (biomass, plants, animals, cells, biotechnology interventions) are of great interest with additive advantages over synthetic materials in terms of biocompatibility, biodegradation, nontoxicity, non-immunogenic and are cost effective systems. Bioinspired nano platforms are proceeding round the world to contrive novel drug delivery carriers using different strategies. This chapter encompasses encroachments in the diverse types of bioinspired polymers and their nano delivery systems. Comprehensive evidence is also concise on delivery systems morphological, biological functionalities from respectively material and their potentialities as persuasive carriers for drug delivery systems.

Bioinspired Nanomaterials

Biological synthesis employing microorganisms, fungi or plants is an alternative method to produce nanoparticles in low-cost and eco-friendly ways. The book covers the synthesis of metal nanoparticles, metal oxide nanostructures and nanocomposite materials, as well as the stability and characterization of bioinspired nanomaterials. Applications include optical and electrochemical sensors, packaging, SERS and drug delivery processes.

Applications of Melanin and Melanin-Like Nanoparticles in Cancer Therapy: A Review of Recent Advances

Thanks to the growing knowledge about cancers and their interactions with the immune system, a huge number of therapeutic cancer vaccines have been developed in the past two decades. Despite encouraging results in pre-clinical models, cancer vaccines have not yet achieved significant clinical efficacy. Several factors may contribute to such poor results, including the difficulty of triggering a strong immune response and the immunosuppressive tumor microenvironment. Many strategies are currently being explored. Different types of adjuvants have been incorporated into vaccine formulations to improve their efficacy, as cancer antigens are usually poorly immunogenic. Nanoparticle systems are promising tools as they act as carriers for antigens and can be surface-modified so that they specifically target antigen-presenting cells in lymph nodes. Bioinspired nanomaterials are ideal candidates thanks to their biocompatibility. Recently, melanin-based nanoparticles were reported to efficiently localize into draining lymphoid tissues and trigger immune responses against loaded antigens. In addition, by virtue of their photochemical properties, melanin-based nanoparticles can also play an immunomodulatory role to promote anti-cancer responses in the context of photothermal therapy. In this review, we discuss the above-mentioned properties of melanin, and summarize the promising results of the melanin-based cancer vaccines recently reported in preclinical models.

Bio-Applications of Multifunctional Melanin Nanoparticles: From Nanomedicine to Nanocosmetics

Bioinspired nanomaterials are ideal components for nanomedicine, by virtue of their expected biocompatibility or even complete lack of toxicity. Natural and artificial melanin-based nanoparticles (MNP), including polydopamine nanoparticles (PDA NP), excel for their extraordinary combination of additional optical, electronic, chemical, photophysical, and photochemical properties. Thanks to these features, melanin plays an important multifunctional role in the design of new platforms for nanomedicine where this material works not only as a mechanical support or scaffold, but as an active component for imaging, even multimodal, and simple or synergistic therapy. The number of examples of bio-applications of MNP increased dramatically in the last decade. Here, we review the most recent ones, focusing on the multiplicity of functions that melanin performs in theranostics platforms with increasing complexity. For the sake of clarity, we start analyzing briefly the main properties of melanin and its derivative as well as main natural sources and synthetic methods, moving to imaging application from mono-modal (fluorescence, photoacoustic, and magnetic resonance) to multi-modal, and then to mono-therapy (drug delivery, anti-oxidant, photothermal, and photodynamic), and finally to theranostics and synergistic therapies, including gene- and immuno- in combination to photothermal and photodynamic. Nanomedicine aims not only at the treatment of diseases, but also to their prevention, and melanin in nature performs a protective action, in the form of nanopigment, against UV-Vis radiations and oxidants. With these functions being at the border between nanomedicine and cosmetics nanotechnology, recently examples of applications of artificial MNP in cosmetics are increasing, paving the road to the birth of the new science of nanocosmetics. In the last part of this review, we summarize and discuss these important recent results that establish evidence of the interconnection between nanomedicine and cosmetics nanotechnology.

Functional Protein-Based Bioinspired Nanomaterials: From Coupled Proteins, Synthetic Approaches, Nanostructures to Applications

Protein-based bioinspired nanomaterials (PBNs) combines the advantage of the size, shape, and surface chemistry of nanomaterials, the morphology and functions of natural materials, and the physical and chemical properties of various proteins. Recently, there are many exciting developments on biomimetic nanomaterials using proteins for different applications including, tissue engineering, drug delivery, diagnosis and therapy, smart materials and structures, and water collection and separation. Protein-based biomaterials with high biocompatibility and biodegradability could be modified to obtain the healing effects of natural organisms after injury by mimicking the extracellular matrix. For cancer and other diseases that are difficult to cure now, new therapeutic methods involving different kinds of biomaterials are studied. The nanomaterials with surface modification, which can achieve high drug loading, can be used as drug carriers to enhance target and trigger deliveries. For environment protection and the sustainability of the world, protein-based nanomaterials are also applied for water treatment. A wide range of contaminants from natural water source, such as organic dyes, oil substances, and multiple heavy ions, could be absorbed by protein-based nanomaterials. This review summarizes the formation and application of functional PBNs, and the details of their nanostructures, the proteins involved, and the synthetic approaches are addressed.

Extremely tough cyclic peptide nanopolymers

ABSTRACTWe present a new class of bioinspired nanomaterials that are stabilized by a combination of covalent and hydrogen bonds. Prior work by others has shown that cyclic peptides can self-assemble to form supramolecular assemblies through backbone-backbone hydrogen bonding. To improve upon this molecular architecture, we develop a synthesis route to polymerize cyclic peptides and form a linear polymer chain that can transition between a rigid nanorod and an unfolded conformation. For a cyclic peptide polymer containing amine-terminated side chains on each ring, we demonstrate self-assembly can be triggered in aqueous solutions by varying the pH. We measure the elastic modulus of the rigid nanorods to be ca. 50 GPa, which is comparable to our molecular dynamics (MD) prediction (ca. 64 GPa). Our results highlight the uniqueness of our molecular architecture, namely their exemplary toughness (up to 3 GJ m-3), in comparison to other cyclic peptide-based assemblies. Finally, we demonstrate amphiphilic cyclic β-peptides are capable of inhibiting the growth of gram-negative and gram-positive bacteria.