https://digital.csic.es/bitstream/10261/63157/4/Gomez-Guillen-collagenreview_CSIC.pdf

Functional and bioactive properties of collagen and gelatin from alternative sources: A review

Twelve derivatives of peptide-amphiphile molecules, designed to self-assemble into nanofibers, are described. The scope of amino acid selection and alkyl tail modification in the peptide-amphiphile molecules are investigated, yielding nanofibers varying in morphology, surface chemistry, and potential bioactivity. The results demonstrate the chemically versatile nature of this supramolecular system and its high potential for manufacturing nanomaterials. In addition, three different modes of self-assembly resulting in nanofibers are described, including pH control, divalent ion induction, and concentration.

https://www.pnas.org/content/pnas/99/8/5133.full.pdf

Peptide-amphiphile nanofibers: A versatile scaffold for the preparation of self-assembling materials

Thermoresponsive hydrogels in biomedical applications.

Fish gelatin: properties, challenges, and prospects as an alternative to mammalian gelatins

Most organs and biological tissues are soft viscoelastic materials with elastic moduli ranging from on the order of 100 Pa for the brain to 100 000 Pa for soft cartilage. Biocompatible synthetic materials already have many applications, but combining chemical compatibility with physiologically appropriate mechanical properties will increase their potential for use both as implants and as substrates for tissue engineering. Understanding and controlling mechanical properties, specifically softness, is important for appropriate physiological function in numerous contexts. The mechanical properties of the substrate on which, or within which, cells are placed can have as large an impact as chemical stimuli on cell morphology, differentiation, motility, and commitment to live or die.

/pdf/soft-biological-materials-and-their-impact-on-cell-function-2cgxxsn5ho.pdf

Soft biological materials and their impact on cell function

Gelatin gels are well-known for their ability to form nonpermanent, physical gels at room temperature and for their numerous applications in photographic and food industries. The difficulties in un...

All Gelatin Networks: 1. Biodiversity and Physical Chemistry†

Structure and rheology of gelatin and collagen gels.

This paper reviews the modern ideas on the process of gelation which have arisen from the analogy between gelation and percolation. The basic features which are common to all types of gels, colloidal or polymeric systems are first recalled; then after a simplified presentation of the percolation model, a few examples illustrating these concepts are chosen (for chemical gelation, a copolymerisation reaction and for physical gelation, the gelatin sol-gel transition). In conclusion, electron micrographs of gel networks (gelatin gel and an inorganic gel of thorium phosphate) are shown, which reveal the great diversity and complexity of the structures.

Gelation—A review

1 Introduction 2 Techniques for the characterisation of physical gels 3 The sol-gel transition 4 General properties of polymer networks 5 Ionic gels 6 Hydrophobically associated networks 7 Helical structures from neutral biopolymers 8 Gelation through phase transformation in synthetic and natural polymers 9 Colloidal gels from proteins and peptides 10 Mixed gels 11 Innovative systems and applications

/pdf/physical-gels-from-biological-and-synthetic-polymers-1ffc75th1q.pdf

Physical Gels from Biological and Synthetic Polymers

This paper deals with the physical and the chemical gelation of gelatin in the presence of a reactant, bisvinyl sulfonemethyl (BVSM). The strategy of this investigation is to separate the contributions of the two types of cross-links in order to deduce the resultant elasticity of the network. In addition, the question raised by several authors concerning an increase of the thermal stability of the triple helices in the presence of cross-links was examined by using several techniques. In this study, the concentration of gelatin and BVSM were kept constant, while the influence of the thermal protocols was put in evidence. The gel formation was followed by rheological, thermodynamic (microcalorimetry), and optical spectroscopy (optical rotation) measurements. The results demonstrate the large differences which arise on the storage moduli by changing the thermal protocols. Cross-linking of the networks in the presence of the triple helices induce a heterogeneous repartition of the bonds, which can form along the triple helices and at the end of the sequences. Consequently, the rubber like network obtained by denaturation of the triple helices is still reminiscent of the initial twist of the chains, and a large modulus is observed, as if rigid segments were still present (storage modulus 10 times larger than for random cross-linking). The hydrogels have an elastic modulus which is larger that the addition of the physical and chemical contributions. The interpretation of the network elasticity is based on the predominant role of the rigid rods of triple helices, where the BVSM cross-links can either modify the ratio between the apparent length and distance between rods, l/d, and/or increase the rigidity of the interchain connections, which are loose coils for the physical gels. The hydrogels investigated have a network which is still close to the percolation threshold of the physical gel, and therefore, the statistical models known for well developed networks cannot be directly validated in these experimental conditions.

Madeleine Djabourov

Papers

All Gelatin Networks: 1. Biodiversity and Physical Chemistry†

Structure and rheology of gelatin and collagen gels.

Gelation—A review

Physical Gels from Biological and Synthetic Polymers

Gelatin hydrogels cross-linked with bisvinyl sulfonemethyl. 2. The physical and chemical networks.