Advanced smart biomaterials and constructs for hard tissue engineering and regeneration

Abstract

Hard tissue repair and regeneration cost hundreds of billions of dollars annually worldwide, and the need has substantially increased as the population has aged. Hard tissues include bone and tooth structures that contain calcium phosphate minerals. Smart biomaterial-based tissue engineering and regenerative medicine methods have the exciting potential to meet this urgent need. Smart biomaterials and constructs refer to biomaterials and constructs that possess instructive/inductive or triggering/stimulating effects on cells and tissues by engineering the material’s responsiveness to internal or external stimuli or have intelligently tailored properties and functions that can promote tissue repair and regeneration. The smart material-based approaches include smart scaffolds and stem cell constructs for bone tissue engineering; smart drug delivery systems to enhance bone regeneration; smart dental resins that respond to pH to protect tooth structures; smart pH-sensitive dental materials to selectively inhibit acid-producing bacteria; smart polymers to modulate biofilm species away from a pathogenic composition and shift towards a healthy composition; and smart materials to suppress biofilms and avoid drug resistance. These smart biomaterials can not only deliver and guide stem cells to improve tissue regeneration and deliver drugs and bioactive agents with spatially and temporarily controlled releases but can also modulate/suppress biofilms and combat infections in wound sites. The new generation of smart biomaterials provides exciting potential and is a promising opportunity to substantially enhance hard tissue engineering and regenerative medicine efficacy.

Functionalized polyhedral oligosilsesquioxane (POSS) based composites for bone tissue engineering: synthesis, computational and biological studies

“…1,2 These biomaterials have shown the ability to promote damaged tissue repair and regeneration by intrinsic osteoinductive properties and/or by triggering stimulating effects on bone cells and tissues, such as pH, ionic strength, temperature, light and magnetic elds. 3 The main advantage in using hybrid materials lies in their ability to mimic the composite structure of natural bone and teeth which are mainly constituted of an organic phase, collagen type 1, and an inorganic component, hydroxyapatite. 4 Ideal composites for tissue engineering applications should be biocompatible, able to mimic and interact with the natural environment of extracellular matrix (ECM), and possess suitable mechanical properties to provide support for the newly formed tissue and also to withstand external forces during bone tissue regeneration.…”

In situ biomimetic formation of nano‐hydroxyapatite crystals on chitosan microspheres

“…Current therapies for bone defects or bone substitutes include autografts and allografts . However, these substitutes have few limitations; for example, autografts may be associated with donor shortage and donor site morbidity, whereas allografts may have the risk of disease transmission and immune responses . Thereby, biocompatible, safe, and functional biomaterials with a gradually increasing importance and field of application today become attractive to be used to fulfill and support the functions of bone tissues in human body .…”

“…1 However, these substitutes have few limitations; for example, autografts may be associated with donor shortage and donor site morbidity, whereas allografts may have the risk of disease transmission and immune responses. 2 Thereby, biocompatible, safe, and functional biomaterials with a gradually increasing importance and field of application today become attractive to be used to fulfill and support the functions of bone tissues in human body. 3 Among these materials, the deposition of nano-hydroxyapatite (nHA) on biopolymeric microspheres is one of the excellent candidates to meet these challenges.…”

“…As the major inorganic component in mammalian hard tissues, nHA is an inexpensive, abundant, and biocompatible material used in composite materials based on biopolymers or hydrogels that have been developed in an effort to repair and regenerate hard tissues in bone defects. 2 On the other hand, chitosan (CS), a natural biodegradable polymer, has been widely used as part of cellular scaffolds, 3,4 biodegradable composites, [5][6][7][8] and drug encapsulation, [9][10][11] to name some. Therefore, the use of CS and nHA is a common configuration for targeting the filling and repair of hard tissues.…”

Polymer- and Hybrid-Based Biomaterials for Interstitial, Connective, Vascular, Nerve, Visceral and Musculoskeletal Tissue Engineering

“…In general, polymer-based hybrid biomaterials: (1) have extensive processing flexibility, tunable mechanical properties, and biodegradability; and (2) possess individual properties and controlled functions, which can be intelligently tailored to actively fill-in the needs of the regeneration in tissue engineering [10,11]. Another development in the area of polymer-based biomaterials for regeneration of hard and soft tissue are smart biomaterials [12]. Such smart functionality can be invoked by chemical, physical and biological stimuli [13][14][15].…”