Antibacterial smart hydrogels: New hope for infectious wound management

Millions of people die annually due to uncured wound infections. Healthcare systems incur high costs to treat wound infections. Tt is predicted to become more challenging due to the rise of multidrug-resistant conditions. During the last decades, smart antibacterial hydrogels could attract attention as a promising solution, especially for skin wound infections. These antibacterial hydrogels are termed 'smart' due to their response to specific physical and chemical environmental stimuli. To deliver different drugs to particular sites in a controlled manner, various types of crosslinking strategies are used in the manufacturing process. Smart hydrogels are designed to provide antimicrobial agents to the infected sites or are built from polymers with inherent disinfectant properties. This paper aims to critically review recent pre-clinical and clinical advances in using smart hydrogels against skin wound infections and propose the next best thing for future trends. For this purpose, an introduction to skin wound healing and disease is presented and intelligent hydrogels responding to different stimuli are introduced. Finally, the most promising investigations are discussed in their related sections. These studies can pave the way for producing new biomaterials with clinical applications

Human-Adaptable Sensors for Wearable Healthcare Monitors

In the introduction chapter, the background, research aims, and context of the thesis have been introduced, including the significance of wearable healthcare monitors. The importance of material selection for wearable devices has been discussed, focusing on key properties such as conductivity, self-healing, elasticity, and adhesion. The review of the literature highlights the various materials used in wearable healthcare devices, including conductive fillers, conductive polymers, and other materials. The different types of sensors and sensing mechanisms for monitoring various parameters such as tissue regeneration, biomolecules, pressure and strain, pH, temperature, and humidity have been discussed. The chapter also sheds light on the fabrication methods used in wearable devices, including 3D printing and the challenges associated with it.This study investigates the development and potential applications of cutting-edge materials, known as (Conductive Adhesive Reconfigurable Elastic gum like material) CareGum, which are designed to address the limitations of traditional rigid electronics in wearable healthcare monitors. CareGum is a novel material comprised of adhesive, self-healing, and stretchable gum-like substances synthesized by crosslinking polyethylene oxide or silk fibroin. The material exhibits mechanical flexibility, electrical conductivity, and self-healing properties. By adjusting the molar ratio of components, crosslinker, and pH, the material's properties can be tailored to suit specific applications.Moreover, CareGum's multimodal sensing capabilities facilitate the simultaneous monitoring of diverse physical parameters, including pressure and strain, temperature and humidity, and pH. This opens up exciting possibilities for diagnosing and treating a wide range of medical conditions. The material's remarkable self-healing properties render it a promising candidate for use in demanding environments. CareGum's rapid self-healing time and high healing efficiency enable it to withstand harsh conditions, further broadening its potential applications in exploration robotics

Injectable hydrogels for cartilage and bone tissue regeneration:A review

Annually, millions of patients suffer from irreversible injury owing to the loss or failure of an organ or tissue caused by accident, aging, or disease. The combination of injectable hydrogels and the science of stem cells have emerged to address this persistent issue in society by generating minimally invasive treatments to augment tissue function. Hydrogels are composed of a cross-linked network of polymers that exhibit a high-water retention capacity, thereby mimicking the wet environment of native cells. Due to their inherent mechanical softness, hydrogels can be used as needle-injectable stem cell carrier materials to mend tissue defects. Hydrogels are made of different natural or synthetic polymers, displaying a broad portfolio of eligible properties, which include biocompatibility, low cytotoxicity, shear-thinning properties as well as tunable biological and physicochemical properties. Presently, novel ongoing developments and native-like hydrogels are increasingly being used broadly to improve the quality of life of those with disabling tissue-related diseases. The present review outlines various future and in-vitro applications of injectable hydrogel-based biomaterials, focusing on the newest ongoing developments of in-situ forming injectable hydrogels for bone and cartilage tissue engineering purposes.</p

Biomimetic Flexible Electronic Materials from Silk Fibroin-MXene Composites Developed <i>via</i> Mussel-Inspired Chemistry as Wearable Pressure Sensors

Since humanity is rapidly moving toward the era of the Internet of Things (IoT) and artificial intelligence (AI) to achieve a higher level of comfort and connection, biocompatible, elastic, and self-healable soft electronic devices such as wearable sensors are needed to overcome the traditional silicon-based electronics rigidity. Inspired by catecholic amino acid (l-3,4-dihydroxyphenylalanine, DOPA) from the mussel foot plaque of marine organisms and Mytilus galloprovincialis mussels, which contribute significantly to the robust underwater adhesion of mussels to the surfaces, here, we report the synthesis and fabrication of a library of materials. These materials comprise adhesive, self-healable, and stretchable gum-like materials, hydrogels, and aerogels based on cross-linking of three components of the silk fibroin (SF) biopolymer, MXene (Ti3C2) two-dimensional nanosheets, and tannic acid (TA). The synthesis relies on the coordination of oxidized SF (SF-DOPA), TA, and polydopamine (PDA)-modified MXene nanosheets with ferric ions to fabricate materials with a mussel-inspired adhesiveness, mechanical flexibility (stretchability), electrical conductivity, and self-healing features. To control the type of the obtained materials as well as their resulting properties, namely, elasticity and electrical conductivity, the molar ratio of TA, MXene, and Fe(III) cross-linker as well as pH values was carefully varied to control the gelation kinetics and phase separation. The resulting optimized materials consist of highly flexible gum to 3D porous homogeneous hydrogels and subsequently aerogels after freeze-drying. The stretchability, electrical conductivity (6.5 × 10–4 S cm–1), human motion sensing performance, and significant strain sensitivity of the final gums confirmed their remarkable performance as intriguing next-generation materials for soft-electronic devices, such as electronic skins and piezoresistive wearable pressure sensors

Biomimetic Flexible Electronic Materials from Silk Fibroin-MXene Composites Developed <i>via</i> Mussel-Inspired Chemistry as Wearable Pressure Sensors

Since humanity is rapidly moving toward the era of the Internet of Things (IoT) and artificial intelligence (AI) to achieve a higher level of comfort and connection, biocompatible, elastic, and self-healable soft electronic devices such as wearable sensors are needed to overcome the traditional silicon-based electronics rigidity. Inspired by catecholic amino acid (l-3,4-dihydroxyphenylalanine, DOPA) from the mussel foot plaque of marine organisms and Mytilus galloprovincialis mussels, which contribute significantly to the robust underwater adhesion of mussels to the surfaces, here, we report the synthesis and fabrication of a library of materials. These materials comprise adhesive, self-healable, and stretchable gum-like materials, hydrogels, and aerogels based on cross-linking of three components of the silk fibroin (SF) biopolymer, MXene (Ti3C2) two-dimensional nanosheets, and tannic acid (TA). The synthesis relies on the coordination of oxidized SF (SF-DOPA), TA, and polydopamine (PDA)-modified MXene nanosheets with ferric ions to fabricate materials with a mussel-inspired adhesiveness, mechanical flexibility (stretchability), electrical conductivity, and self-healing features. To control the type of the obtained materials as well as their resulting properties, namely, elasticity and electrical conductivity, the molar ratio of TA, MXene, and Fe(III) cross-linker as well as pH values was carefully varied to control the gelation kinetics and phase separation. The resulting optimized materials consist of highly flexible gum to 3D porous homogeneous hydrogels and subsequently aerogels after freeze-drying. The stretchability, electrical conductivity (6.5 × 10–4 S cm–1), human motion sensing performance, and significant strain sensitivity of the final gums confirmed their remarkable performance as intriguing next-generation materials for soft-electronic devices, such as electronic skins and piezoresistive wearable pressure sensors

Composite Graded Melt Electrowritten Scaffolds for Regeneration of the Periodontal Ligament-to-Bone Interface

Periodontitis is a ubiquitous chronic inflammatory, bacteria-triggered oral disease affecting the adult population. If left untreated, periodontitis can lead to severe tissue destruction, eventually resulting in tooth loss. Despite previous efforts in clinically managing the disease, therapeutic strategies are still lacking. Herein, melt electrowriting (MEW) is utilized to develop a compositionally and structurally tailored graded scaffold for regeneration of the periodontal ligament-to-bone interface. The composite scaffolds, consisting of fibers of polycaprolactone (PCL) and fibers of PCL-containing magnesium phosphate (MgP) were fabricated using MEW. To maximize the bond between bone (MgP) and ligament (PCL) regions, we evaluated two different fiber architectures in the interface area. These were a crosshatch pattern at a 0/90° angle and a random pattern. MgP fibrous scaffolds were able to promote in vitro bone formation even in culture media devoid of osteogenic supplements. Mechanical properties after MgP incorporation resulted in an increase of the elastic modulus and yield stress of the scaffolds, and fiber orientation in the interfacial zone affected the interfacial toughness. Composite graded MEW scaffolds enhanced bone fill when they were implanted in an in vivo periodontal fenestration defect model in rats. The presence of an interfacial zone allows coordinated regeneration of multitissues, as indicated by higher expression of bone, ligament, and cementoblastic markers compared to empty defects. Collectively, MEW-fabricated scaffolds having compositionally and structurally tailored zones exhibit a good mimicry of the periodontal complex, with excellent regenerative capacity and great potential as a defect-specific treatment strategy