Biomimetic materials

Biomimetic materials

1. Biomimetic Materials Tomsk Polytechnic University   Исследовательская школа химических и биомедицинских Antonio Di Martino [email protected]

2. BIOMIMETIC MATERIALS materials developed by replication or imitation of biological structures Honeycomb Wood fibers Nacre Mother of pearl H edgehog quills Bio-inspired materials engineering : applying biological principles to synthetize new materials Bio-mediated materials engineering : take advantages of biological materials properties by incorporation into another system Biomimicry : new science that studies nature's models and then imitates or takes inspiration from these designs and processes to solve human problems

3. Biological materials Typically found as composite structures, can be classified as: Non-mineralized ( soft) Mineralized (hard) Proteins ( e.g. collagen, keratin, elastin) Polysaccharides (e.g. chitin, cellulose, hemicellulose etc ) Soft tissue Intramolecular bonds such as H-bond; crosslinking of polymer chains m uscles fat blood vessels s ynovial membranes Organic + Inorganic crystals ( high strength) Inorganic components Calcium carbonate – CaCO 3 Calcium phosphate – Ca 3 (PO 4 ) 2 Silicon dioxide – SiO 2 Iron oxide – Fe 2 O 3 Hard tissues are: bones Soft tissues are

4. Biomimetic materials Nature synthetize its materials under mild conditions: Ambient temperature Ambient pressure Near-neutral pH The idea behind the biomimetics are: Understand the parameters which control biological self-assembly and mineralization Understand both the synthesis-structure and structure-property r elationship of biological materials Developing of next-generation high performance multifunctional materials

5. Advantages of biological systems Six major characteristics that make biological systems advantageous: Self-assembly Multi-functionality (same material for different application) Hydration Evolution Synthesis in mild conditions Hierarchical structures Hierarchical structure of bones

6. Nacre-inspired materials Bio-materials , such as mammalian bones, crustacean shells and reptile skins have unique properties that are intimately associated to their structure Associated properties are often the result of a combination of two distinct components: a ‘ hard’ component , and a ‘soft’ component , consisting of organic matter, such as collagen, elastin or cellulose. N acre consists of 95 wt % of aragonite , which is a crystalline form of CaCO 3 and 5 wt % organic materials , which are proteins and polysaccharides

7. Nacre-structure Proteins

8. Nacre inspired materials Nacre inspired porous scaffolds for bone repair have been established via a combination of strategies, including electrospinning, phase separation, and 3D printing Polyimide layers = soft part = Hard part Clay ( глниа ) = SiO 2 , Al 2 O 3 , MgO + organic compounds TiO 2 polyimide polydimethylsiloxane Incorporation of antibacterial compounds on the surface ; e.g. Silver nanoparticles Mechanical properties like natural bones c hitosan h yaluronic acid

9. Biomimetic artificial muscles Artificial muscles  are materials or devices that mimic natural muscles  and can reversibly contract, expand, or rotate within one component due to an external stimulus (such as voltage, current, pressure or temperature) Artificial muscles are divided in three major groups based on the actuation mechanism Electric actuation – Electroactive polymers (EAPs) Pneumatic actuation (PAMs) Thermal actuation – Shape memory alloy (SMA) – Shape memory polymers (SMPs) Pneumatic Artificial Muscles

10. Electroactive polymers (EPAs)  EPAs = polymers that exhibit a change in size or shape when stimulated by an electric field Large deformation when a large force is applied over time EPAs are divided in two main groups: Dielectric and Ionic Dielectric = electrostatic forces between two electrodes squeeze the polymer. It is required high voltage to produce high electric fields. Ionic = the response is related by the displacement of the ions inside the polymers ( e.g conductive polymers) The cations in the ionic polymer-metal composite are randomly oriented in the absence of an electric field. Once a field is applied the cations gather to the side of the polymer causing the polymer to bend. Applied voltage = polymer expand (blue) V oltage is removed (red muscles) the polymer returns to original state.

11. Shape Memory Polymers (SMPs) Polymers with ability to return from a deformed state ( temporary shape ) to their original ( permanent ) shape induced by an external stimulus (trigger) heat electric magnetic light chemical

12. Shape memory polymers (SMPs) Physical cross-linked polymers Chemical cross-linked polymers The   thermal-induced  SMPs  as  the most  researched  SMPs,  can  change  their  shape  in   a predefined  way under  the  stimulus of  heat Electric-induced SMPs Magnetic-induced  SMPs indirect  thermal-induced  SMPs  electricity  or magnetism   are transformed  to   heating Photo-induced   SMPs  form  or  destroy the networks in polymers under different wavelength  Chemical-induced  SMPs   water induced   solvent-induced  pH-induced

13. Shape memory polymers (SMPs) Traditional  SMPs – D ual SMPs Temporary shape Permanent shape T riple SMPs 2 Temporary shapes Permanent shape Quadruple SMPs 3 Temporary shapes Permanent shape   Multi-stimuli   SMPs     Multi-functional  SMPs  polymers  can recover  shape  under  more  than  one  stimuli possess not only shape memory properties but  also  other  stimuli-responsive  function,  such  as  healing, drug delivery

14. Composition of biodegradable/biocompatible shape memory systems

15. Shape  memory  effect  of  PDLLA/HA composite  at  70  °C Examples of SMPs Temperature   Shape memory poly( ε- caprolactone -co-DL- lactide )  (PCLA) Water It recovers the shape after 30 minutes at body temperature It takes 36 seconds in hot water to recover the initial shape (in vitro) The same polymer in vivo used as stent for esophagus Soft material Adaptable to tissue

16. Examples of SMPs Water-induced SMPs   The  absorbed  water  can  be divided into  free  water = cannot  affect  the  properties  of  the   SMPs = no changes of shape b ounded water   = affect the shape =  weaken the hydrogen bonds in polymer  networks to  increase the flexibility of the macromolecular  chains Poly(vinyl  alcohol)  (PVA)   nontoxic  nature  and biocompatible   material   both  the  chemically   and physically   crosslinked  networks good   water induced  shape memory effect MCC = microscristalline cellulose Cellulose

17. pH-induced SMPs Body compartments  have  variations  in  physiological pH   values In pathological conditions the pH is some body compartments can be different than in healthy conditions pH sensitive  groups amino carboxyl   sulfonic pH  induced  shape  memory  effect  is  achieved  through switching  effect  of  hydrogen  bond  interactions  of  pH sensitive  groups  in  polymer The pH-sensitive memory effect of  polyurethane with pyridine  rings 1) The   disturbed  hydrogen  bond interactions of  pyridine  rings  cause   swelling   in   acid  condition 2) The   formed  hydrogen   bond interactions  lead to  de-swelling  in   base condition

18. Light induce SMPs Photosensitive functional group   e.g azobenzenes I nterpenetrating  polymer network (IPN polymer)  containing cinnamylidene  acetic  acid  terminal  group. 100%  elongation Initial state λ  > 300  nm  for 35  min deformation λ = 254  nm for 120  min recovery cinnamylidene  acetic  acid  

19. Reversible SMPs   one-way  SMEs  materials  can  remember  and  recover shape in  only one direction two-way  SMEs the  materials can reversibly  change  shapes between  temporary shape and permanent  shape  under  different  external  stimuli (reversible  SME) reversible  bidirectional  shape  memory  effect

20. Biomedical Applications SMPs-based Biomaterials for Tissue Engineering (a) compressed scaffold  (b) the scaffold implanted in  the  rabbit  mandibular  bone  defect   (c) and (d )  the  scaffold  cans  recovery  the original shape in vivo  after 10  min  of  implantation

21. SMPs-based Substrate to Control Cell Morphology rat  bone marrow mesenchymal stem cell ( rBMSC ) shape reorganization  of actin  cytoskeleton, and differentiation by the dynamic change of a microgrooved  surface  activated  with  the  thermal-induced  shape memory effect Confocal laser scanning microscopy images

22. SMPs-based Substrate to Control Cell Morphology

23. Shape Memory Alloy (SMA) Alloy : combination of metals or a combination of one or more metals with non-metallic elements A  shape-memory alloy : it  is an alloy   that can be deformed when cold  but returns to its pre-deformed ("remembered") shape when heated.

24. Shape Memory Alloy The two most prevalent shape-memory alloys are:   NiTinol wires (Ni- Ti ) Copper – Aluminium -Nickel ( Cu-Al-Ni) Nickel- Titanium ( NiTi ) Others SMA : Fe- Mn -Si ; Cu-Zn-Al; Cu-Al-Ni; Au alloy with Fe, Zn, Cu

25. Shape memory effect The shape memory effect (SME) occurs because a temperature-induced phase transformation reverses deformation Two common effects are one-way and two-way shape memory S tart Apply a deformation Heating Cooling ONE-WAY DEFORMATION TWO-WAY DEFORMATION S tart Apply a deformation Heating T 1 Heating T 2 Cooling T 1 <T 2 The material remember two different shapes at two different temperatures

26. Biomedical applications Robotic hands SMA to move fingers Liftware spoon To counteract the tremor associate with Parkinson s disease Dental braces

27. References Noh, Insup , ed. Biomimetic Medical Materials: From Nanotechnology to 3D Bioprinting . Vol. 1064. Springer, 2018 . Reddy, Roopa , and Narendra Reddy. "Biomimetic approaches for tissue engineering." Journal of Biomaterials Science, Polymer Edition 29.14 (2018): 1667-1685 . Annu . Rev . Phys. Chem . 2018. 69:23–57 Trans.R.Soc A 377; 20180268 Chinese J. Polym. Sci. 2018, 36,  905–917 Mu, Tong, et al. "Shape memory polymers for composites." Composites Science and Technology 160 (2018): 169-198 . Chen, Hong-Mei, Lin Wang, and Shao-Bing Zhou. "Recent progress in shape memory polymers for biomedical applications." Chinese Journal of Polymer Science 36.8 (2018): 905-917 . Liang, Ruixue , et al. "Molecular design, synthesis and biomedical applications of stimuli-responsive shape memory hydrogels." European Polymer Journal (2019 ). Hardy, John G., et al. "Responsive Biomaterials: Advances in Materials Based on Shape‐Memory Polymers." Advanced Materials 28.27 (2016): 5717-5724.

28. Kirillova , Alina, and Leonid Ionov . "Shape-changing polymers for biomedical applications." Journal of Materials Chemistry B 7.10 (2019): 1597-1624. Xie , Fang, et al. "Thermoset shape memory polymers and their composites." Journal of Intelligent Material Systems and Structures 27.18 (2016): 2433-2455. Lu, Wei, et al. "Supramolecular shape memory hydrogels: a new bridge between stimuli-responsive polymers and supramolecular chemistry." Chemical Society Reviews 46.5 (2017): 1284-1294. Löwenberg , Candy, et al. "Shape-memory hydrogels: evolution of structural principles to enable shape switching of hydrophilic polymer networks." Accounts of chemical research 50.4 (2017): 723-732.