Chiral Biomaterials: From Molecular Design to Regenerative Medicine

Abstract

molecular asymmetry was a critical event in early organic evolution. [ 4 ] Evolution by natural selection led to preference for the coexistence of both asymmetry and symmetry, particularly observed in the "distribution of body parts and shapes." Much of organic life has body plan symmetry categorized into six main types. [ 5 ] Radial, bilateral, and spherical symmetry are common formations among body parts, shapes, and patterns. Asymmetric structures occur in the arrangement of fl ower petals and sepals, protein folding, spiraling of biomaterial fi bers, and the distribution of organs in the human body. Asymmetry and symmetry phenomena are exploited in biotechnology and biomaterials technology. For instance, asymmetrical self-organizing molecular precursors can form new types of organized organic and inorganic matter. [ 6 ] Asymmetrical structure occurs among active biological molecules and structural biological molecules. It is intrinsic to individual cell cytoskeletal architecture and the behavior of human cells. Comprehensive chiral information (structure and interplay) about molecules, materials, and living human cells will promote new strategies for innovation in biomimetic healthcare materials. Materials synthesized by biomimetic principles and processes copy structure, architecture, and morphologies of biomaterials in organisms. However, the installation of chirality into materials fabrication by biomimetic synthesis has been negligible. The emulation of chiral synthesis with base molecules and chiral self-organization into large structures is not straightforward. In some biological objects, chiral structures are made from achiral constituents. An important study showed that specialized "chiral amino acids" promoted chirality on chiral calcium carbonate crystals by binding onto the lowest energy surfaces. [ 7 ] Another strategy to promote the expression of materials chirality is to use special biological molecules that arrange the synthetic biological molecules into chiral architectures. [ 8 ] For example, chiral lipids have been used to generate high aspect ratio silica morphologies (diffi cult by conventional chemistry) with helical spirals. [ 9 ] Harnessing Chiral Designs for BiomedicineThe principal functions of chiral architecture in biomolecules are understood to enhance specifi city and recognition leading to fi tter functions and presumably reducing energy usage. This is a driving force for evolution of fi tness. Underpinning chiral Chirality is integral to biological complexity. Chiral biomolecules are central to all fundamental recognition, conformational and replication functions in biological systems. Chirality also exists in living cells and higher order biological structures. Less is known about the cellular interactions with chirality, although most living cells are imprinted with chiral-based signatures. The harnessing of molecular, supramolecular, and structural chirality has been largely overlooked in biomaterials chemistry and the engineering of biological structures for regenerative me...

Circularly polarized laser emission induced in isotropic and achiral dye systems

“…Only the molecules whose absorption dipole moments unit vectors e d are properly aligned with the electric field E p of the pump radiation will be excited. The probability of being excited will be then proportional to | E p ·e d | 2 , i.e ., it will be proportional to cos 2 ϑ, where ϑ is the dihedral angle formed by the absorption dipole moment and the electric field vector (see Supplementary Notes for a detailed description). Once the molecules have been excited, they must rotate so that their emission dipole moment is coupled to any of the cavity modes, i.e ., perpendicular to the resonator axis and lying in the ZY plane.…”

“…Chirality, the asymmetry property by which an object or structure and its mirror image are not superimposable, plays an important role in material science 1 2 . Photonics is not an exception, and the growing interest on chiroptical phenomenon finds its roots in the resolution provided by the circular polarization (CP), which becomes essential in many advanced photonic technologies, such as information storage and processing 3 4 , communication of spin information 5 or ellipsometry-based tomography 6 7 .…”

Microscopic origin of the chiroptical response of optical media

“…This is observed in the metabolism of pharmaceuticals such as thalidomide ( 4 ) and penicillamine ( 5 ), wherein one enantiomer produces medicinal effects and the other toxicity. Thus, enantiomer discrimination techniques such as circular dichroism (CD) spectroscopy are essential for minimizing the toxic effects of medications ( 6 , 7 ), developing effective treatments for diseases ( 8 , 9 ), and probing the nature of chiral systems ( 10 ). In addition to enantiomer discrimination, CD spectroscopy also provides information on protein secondary structures crucial to understanding protein folding ( 11 , 12 ).…”

Chiral Recognition of L- and D- Amino Acid by Porphyrin Supramolecular Aggregates

“…In this respect, the chiral recognition of chiral molecules assumes a key role in biotechnology and biochemistry [4,5]. In addition, chirality has applications in numerous scientific fields from medicinal chemistry to material science [6,7,8], and sensing [9,10]. For these reasons, the study on the chirality induction from a molecular assembly to a supramolecular assembly has been an issue of great interest for many years [11].…”