This book deals with a unique aspect of materials science in tissue engineering, in particular the applications of smart materials for tissue engineering. This book is an attempt to document recent advances in smart materials applications in tissue engineering.
Smart Biomaterials for Cardiovascular Tissue
Advances of Smart Materials for Wound Healing 258 Junjie Deng, Peter Y. Li and Hao Cheng
Applications of Magnetic-Responsive Materials for
Intestinal Tissue Engineering with Intestinal Stem Cells 329 Zahra Davoudi and Qun Wang
Smart Materials and Systems as Artificial Pancreas for
Smart Materials for Nerve Regeneration and Neural
Smart Cell Culture for Tissue Engineering 409 Yehudah Pardo and Minglin Ma
Flexible Micro- and Nanoelectronics for Tissue
Smart Materials to Regulate the Fate of Stem Cells 473 Jiabin Zhang, Hu Zhang and Xia Xu
Smart Drug Delivery Systems for Tissue
Smart Materials for Central Nervous System Cell
Smart Multifunctional Tissue Engineering Scaffolds 558 Qilong Zhao and Min Wang
Applications of Smart Microfluidic Systems in Tissue
Smart 3D Printing Materials for Tissue
Smart Materials-Originated Microfluidic Systems
Introduction
Conventional tissue engineering approaches involve the use of a scaffold mainly as a structural element with defined physicochemical, mechanical and biological properties and appropriate architecture and porosity to support cell metabolism. Basic material requirements for use in tissue engineering include biocompatibility, histocompatibility, non-toxicity, and the ability to construct a suitable scaffold with the required functionalities.
Applications of Multifunctional Scaffolds in Tissue Engineering
- Bone and Cartilage
- Natural Polymers
- Synthetic Polymers
- Inorganic Materials
- Hybrid Polymer/Inorganic Materials
- Hybrid Synthetic/Natural Polymers
- Muscle
- Skin Tissue Engineering
- Cardiovascular
- Surface Coatings to Enhance Endothelialization
- Tissue Engineered Cardiovascular Devices
- Neural Tissue Engineering
Small pharmaceuticals have been widely used to improve the angiogenic and osteogenic properties of inorganic scaffolds. Biomaterial scaffolds have been shown in animal models to play a key role in enhancing the therapeutic potential of cells and growth factors.
Clinical Potential and Applications of
In addition, carbon nanotube composites163 have been used as multifunctional substrates for the differentiation of human neural stem cells and soft carbon nanotube fiber microelectrodes for safe stimulation and recording of neural activity.164. Multifunctional fibers that allow simultaneous optical, electrical, and chemical stimulation of neural circuits have been developed using a thermal drawing process165 and have been assembled into synthetic nerve-guiding scaffolds that can replace nerve autografts for repairing damaged tissue after peripheral nerve injury. 166 Conductive fiber-reinforced polymer composites 167 as well as lysinated molecular organic semiconductors are innovative materials that offer optoelectronic functions with improved biocompatibility and two-way communication of nerve cells. as therapeutic agents in neurodegenerative diseases.169.
Multifunctional Scaffolds in Tissue Engineering
Conclusions
Muscle tissue engineering is still in its infancy due to the peculiar organization of skeletal muscle, which requires smart scaffolds with multiple functions that will provide the appropriate mechanical and bioactive signals for cells to adhere, proliferate, form networks, and replace dysfunctional tissue.
Introduction
Considerations of Smart Materials in Tissue Engineering
- Biocompatibility
- Structure
Classification of Smart Materials in Tissue Engineering
- Synthetic Materials
- Biosynthetic Materials
- Biologic Materials
- Protein-Based Materials
- Polysaccharide-Based Materials
- ECM Materials
Wound healing after burn injuries is a good example of the potential clinical application of a smart hydrogel. Gels produced from eCM can achieve any desired. Figure 2.3 Structure of the extracellular matrix (eCM).
Clinical Translation of Smart Material for Tissue Engineering
In addition to increasing patient numbers, researchers evaluated muscle repair and functional outcomes after implantation of one of three sources of eCM materials: UBM, SiS, and dermis. The clinical translation of eCM scaffold materials for esophageal reconstruction represents an important alternative for a challenging field where high morbidity and increased risk of infections are expected after pedicled muscle flap implantation or jejunal interposition.
Future Challenges for Translation of Smart Biomaterials in Tissue Engineering
Brown, i Host Response to Biomaterials The Impact of Host Response on Biomaterial Selection, red. Walter, Molecular Biology of the Cell, Taylor og Francis CrC, USA, 5. udg., 2012, pp.
Introduction
Stimuli-Responsive Injectable Polymeric Hydrogels
- Temperature-Responsive Injectable Hydrogels
- pH-Responsive Injectable Hydrogels
- Enzyme-Responsive Injectable Hydrogels
- Sol-to-Gel Transition
- Gel-to-Sol Transition
Sulfamethazine oligomers (SMos) with ph sensitivity were linked to the end groups of the thermosensitive block copolymer poly(ε-caprolactone-colactide)–poly(ethylene glycol)–poly(ε-caprolactone-colactide) to create thermo- and ph-sensitive dual SMo –pCLa–peg–pCLa–SMo copolymer. Under physiological conditions (37 °C and ph 7.4), the copolymer rapidly formed a stable hydrogel, while it underwent a gel-sol transition at 37 °C and ph 8.0.
Injectable Supramolecular Hydrogels
Peptide-based small molecular hydrogels, as a type of supramolecular hydrogels, have been widely researched and applied in the field of tissue engineering.29 Xu et al. Since the peptide sequence can provide a functional site for cell adhesion and further modulate cell proliferation and differentiation, this type of injectable hydrogel offers a wide range of potential applications in tissue engineering.31.
Application of Injectable Smart Materials for Tissue Repair and Regeneration
- Bone
- Cartilage
- Skin
- Cardiovascular
- Skeletal Muscle and Tendon
In vitro tests show that bone marrow stromal cells embedded in the hydrogel can differentiate into osteoblasts and produce a mineralized matrix.64. Both in vitro and in vivo experiments show that this hydrogel can stimulate osteoblast differentiation of adipose-derived stem cells in the absence of osteogenic factors.
Conclusion and Perspective
When transplanted into the ischemic limbs, this system dramatically improved MSC retention and differentiation, and a pronounced effect for ischemic limb regeneration has been observed.137. Furthermore, smart materials that could respond to the stimuli of endogenous signals show their unique advantages in mediating the interaction between the implanted materials and the host, which could further regulate the immunological response and induce cell ingrowth, thus promoting tissue regeneration and remodeling.
Introduction
Challenges related to the manipulation of single pSi particles or sharp edge-induced in vivo inflammatory response of the as-prepared microparticles can be readily addressed by using a combination of biodegradable polymers (or hydrogels) and porous silicon. Some significant advantages are readily envisaged: flexible mechanical properties of the polymer allow for easy molding into various shapes and forms required for the site of an injury (since the polymer matrix can conform to the specific shape of ' an actual defect or trauma site); opportunities for incorporating sites that demonstrate different degradation kinetics (two-phase drug delivery vehicles and beyond); more easy incorporation of heterogeneous materials (hard/soft).
Fundamentals of Porous Silicon (pSi)
- Porous Silicon (pSi) Can Be Processed into a Variety of Shapes and Forms
- Control Over Pore Structure
- Surface Chemistry
- Cell Attachment and Differentiation on Porous Silicon
- Advantages of pSi/Polymer Composites as Implants for Tissue Engineering
54 (2011) the pore openings of the pSi nanoparticles were grafted with a ph-responsive nanovalve of poly(β-amino. ester) and the external surface with pluronic f-127. Many of the above points regarding the influence of surface chemistry on the properties of a given drug loaded into pSi can be illustrated by noting selected highlights from a recent review by Wang et al., which shows the influence of have not studied surface chemistry of pSi. only on the dissolution of the carrier itself but also drug loading and consequently its release kinetics.33 they analyzed three types of porous silicon surfaces with a mesoporous structure: hydrophobic ash-prepared (hydrogen-terminated) pSi, hydrophobic octyl-functionalized pSi, and hydrophilic surface oxidized pSi.
Porous Silicon as a “Smart” Biomaterial
Porous Silicon/Polymer as a “Smart”
Tissue-Engineering Scaffold
Clinical Potential
Chapter 4104 Figure 4.6 (a) SeM image of a drained pCl/paNi/1% pSi sponge after bias application showing the presence of Cap. C) a one-month soaking of a similar sample in SBf at 37 °C with zero bias.
Summary and Future Opportunities
Acknowledgements
Introduction
Many properties of electrical systems have been demonstrated and demonstrated in living cells.21,22 therefore, electrical stimulation has been shown to induce beneficial cellular responses in some electrically sensitive tissues, such as nerve, bone, muscle, and heart tissue. Based on literature research over the past decade, this chapter summarizes the most commonly used conductive materials in biomedical applications and common modification strategies to improve their biocompatibility and biodegradability for biomedical applications, and their major achievements in the fields of nerve, bone, muscle, and cardiac tissue engineering.
Conductive Materials
- Conductive Polymers
- Polypyrrole
- Polyaniline
- Polythiophene Derivatives
- Piezoelectric Polymeric Materials
- Other Novel Conductive Nanomaterials
- Carbon Nanotubes
- Graphene
- Self-Assembled Conductive Hydrogels
Conducting polymers show remarkable capacity to effectively combine the electrical properties of metals and the physicochemical properties of organic polymers.36 Typically, conducting polymers are organic polymers composed of high electrical properties with loosely held electrons in the backbone, and doping is an essential process to obtain polymers with high conductivity. .37,38 have created great importance for many biomedical applications, including cell adhesion, proliferation, and differentiation regulated by electrical stimulation.33,39–42 several different types of conducting polymers, such as polypyrrole (ppy), polyaniline derivatives ( pani) and polythiophene, have been developed and investigated for their potential use in the field of tissue engineering. Carbon nanotubes (Cnts) have emerged as promising conductive nanomaterials for biomedical applications due to their unique properties.
Biocompatibility and Biodegradation of Conductive Materials
- Biocompatibility
- Biodegradability
3d graphene foams (3d-gF) are graphene derivatives with 3d porous structures and electrical conductivity,126 which can help advance tissue engineering, especially for new scaffolds. For example, it has been previously reported in numerous studies that the biodegradability properties of ppy can be adjusted by adding ionizable or hydrolyzable side groups to the ppy backbone, especially butyric acid and butyric ester, respectively, and the degradation rate. can be corrected depending on the amount of each side group added to the conducting material.
Modification of Conductive Materials
- Bioactive Molecules
- Biocompatible Polymers
- Topography Modification of Conductive Materials
Modification and functionalization of conductive materials with various biomolecules has provided us with strategies to functionalize them with biological sensing elements, even to modulate various signaling pathways required for cellular processes.
Applications of Conductive Materials for Tissue Engineering
- Applications for Nerve Tissue Engineering
- Applications for Bone Tissue Engineering
- Applications for Muscle Tissue Engineering
- Applications for Cardiac Tissue Engineering
131Applications of Conductive Materials for Tissue Engineering Figure 5.11 Fluorescence images showing the growth of C2C12 cells labeled with phalloidin (cytoskeleton; red) and Cytox-labeled (nucleus; green). Boccaccini, Development and characterization of novel electrically conductive pani–pgs composites for cardiac tissue engineering applications, Copyright (2014) with permission from Elsevier.
Conclusions and Perspectives
133Applications of conductive materials for tissue engineering Figure 5.12 Cardiac cell phenotype on Cnt-gelMa hydrogels. Cx-43 (red) revealed that heart tissues (eight-day culture) on (a) pristine gelMa and (B) Cnt-gelMa were phenotypically different.
Introduction
Smart biomaterials are new biomaterials that can respond to changes in the environment when one of their properties changes due to external conditions such as pH, temperature, pressure and light.31,32 A large number of smart biomaterials have been developed in recent decades. created with improved responsiveness, biocompatibility, stealth properties, specificity and other critical properties such as shape memory, promotion of vascularization, directing cell phenotype, injectability, etc.
Recent Advances of Smart Biomaterials
- Smart Biomaterials that Mimic the Native Microenvironment
- Smart Biomaterials that Overcome Suffocation
- Smart Biomaterials that Promote Vascularization
- Smart Biomaterials that Overcome a Foreign Body Reaction
- Smart Biomaterials that Direct Cell Phenotype
- Injectable Smart Biomaterials
- Smart Biomaterials that Remember Shapes
Chapter 6156 Figure 6.9 Chemical structures of three materials.78 reproduced with permission from Macmillan publishers Ltd: a. 157 Smart Biomaterials for Cell Encapsulation Figure 6.10 (a) Live/dead staining of islet cells encapsulated in 0.5 mm capsule and 1.5 mm capsule to check their viability.
Conclusion and Perspective
Introduction
Live cells can be cultured in vitro to bind to the matrix before implantation or induced in vivo to migrate into the implant after implantation. Later, the focus shifted to absorbable biomaterials, based on the development of absorbable polymers such as polycaprolactone (pCL), poly(glycolic acid) (pga), poly(lactic acid) (pLa) and poly(co-lactic-co- glycolic acid) (pLga).
Multi-Functional Biomaterials for Bone Tissue Engineering
- Passive Biomaterials for Mechanical Support
- Active Scaffolds
- Biomaterials for Biomolecular Delivery
- Biomaterials for Biosensing
Meanwhile, the introduction of individual growth factors resulted in negligible bone formation even after 22 weeks.62 In order to achieve the maximum therapeutic effect, the sequence of gF release can also be changed with this simultaneous administration. When co-applied with dissolved pLga as a coating for allograft specimens, FtY720 promoted greater osseointegration of the implant interface with superior mechanical properties (i.e., elasticity and compressive strength) than uncoated and pLga-only control allografts six weeks after implantation.
