Nano-/micron-sized bioactive glass (BG) particles are attractive candidates for both soft and hard tissue engineering. They can chemically bond to the host tissues, enhance new tissue formation, activate cell proliferation, stimulate the genetic expression of proteins, and trigger unique anti-bacterial, anti-inflammatory, and anti-cancer functionalities. Recently, composites based on biopolymers and BG particles have been developed with various state-of-the-art techniques for tissue engineering. Gelatin, a semi-synthetic biopolymer, has attracted the attention of researchers because it is derived from the most abundant protein in the body, viz., collagen. It is a polymer that can be dissolved in water and processed to acquire different configurations, such as hydrogels, fibers, films, and scaffolds. Searching “bioactive glass gelatin” in the tile on Scopus renders 80 highly relevant articles published in the last ~10 years, which signifies the importance of such composites. First, this review addresses the basic concepts of soft and hard tissue engineering, including the healing mechanisms and limitations ahead. Then, current knowledge on gelatin/BG composites including composition, processing and properties is summarized and discussed both for soft and hard tissue applications. This review explores physical, chemical and mechanical features and ion-release effects of such composites concerning osteogenic and angiogenic responses in vivo and in vitro. Additionally, recent developments of BG/gelatin composites using 3D/4D printing for tissue engineering are presented. Finally, the perspectives and current challenges in developing desirable composites for the regeneration of different tissues are outlined.

This article reviews promising studies on the design, manufacturing, microstructure, properties, and applications of glass‐ceramics containing ZrO₂ and relevant glass‐ceramic matrix composites. After the addition of ZrO₂ to a glass‐ceramic composition, it can persist in the residual glassy phase, facilitate nucleation, and/or precipitate as ZrO₂ or another zirconate crystalline phase. Also, ZrO₂‐reinforced or ZrO₂‐toughened glass‐ceramics can be designed as composites. In this article, the term “ZrO₂‐containing glass‐ceramics” encompasses all these scenarios in which ZrO₂ is present. Such glass‐ceramics offer a wide range of applications in modern industries, including but not limited to architecture, optics, dentistry, medicine, and energy. Since S. Donald Stookey's discovery of glass‐ceramics in the early 1950s, the most important scientific efforts reported in the literature are reviewed. ZrO₂ is commonly added to glass‐ceramics to promote nucleation. As a result, the role of ZrO₂ in structural modification of residual glass and stimulating the nucleation in glass‐ceramic is first discussed. ZrO₂ can also be designed into the main crystalline phase of glass‐ceramics, contributing achieving super high fracture toughness above 4 MPa·m^0.5. Experimental and computational studies are reviewed in detail to elucidate how the transformation toughening and other mechanisms help to achieve such high values of fracture toughness. Sintered and glass‐ceramic matrix composites also show promise, where ZrO₂ contributes to improved stability and mechanical properties. Finally, we hope this article will provoke interest in glass‐ceramic materials in both the scientific and industrial communities so that their tremendous technological potential in developing, for example, tough, thermally stable, transparent, and biologically compatible materials can be realized more widely.

Both unwanted and induced crystallization can impact bioactivity, physical and mechanical properties of bioactive glasses (BGs). Uncontrolled crystallization has negative consequences, rendering BGs unreliable. However, by manipulating the type, size, shape, and quantity of crystals in BGs, plenty of opportunities arise for controlling, for example, mechanical properties and degradability, leading to unique applications and improved performance. Understanding crystallization is a key step in developing bioactive glasses and glass‐ceramics (BGCs), and both fundamental and experimental research can aid in the design of BGCs for processing and biological function. In this perspective, we discuss the sources of crystallization and how controlled crystallization facilitates the functionalization of bioactive scaffolds, hybrids, coatings, composites, cements, and fibers.

Nano/micron-sized bioactive glass (BG) particles are attractive candidates for both soft and hard tissue engineering. They can chemically bond to the host tissues, enhance new tissue formation, activate cell proliferation, stimulate the genetic expression of proteins, and trigger unique an-ti-bacterial, anti-inflammatory, and anti-cancer functionalities. Recently, composites based on bi-opolymers and BG particles have been developed with various state-of-the-art techniques for tis-sue engineering. Gelatin, a semi-synthetic biopolymer, has attracted the attention of researchers because it is derived from the most abundant protein in the body, viz., collagen. It is a polymer that can be dissolved in water and processed to acquire different configurations, such as hydro-gels, fibers, films, scaffolds, etc. Searching "bioactive glass gelatin" in the tile on Scopus renders 80 highly relevant articles published in the last ~10 years, which signifies the importance of such composites. First, this review addresses the basic concepts of soft and hard tissue engineering, in-cluding the healing mechanisms and limitations ahead. Then, current knowledge on gelatin/BG composites including composition, processing and properties is summarized and discussed both for soft and hard tissue applications. This review explores physical, chemical and mechanical features and ion-release effects of such composites concerning osteogenic and angiogenic respons-es in vivo and in vitro. Additionally, recent developments of BG/gelatin composites using 3D/4D printing for tissue engineering are presented. Finally, the perspectives and current challenges in developing desirable composites for the regeneration of different tissues are outlined.