Explore the vast range of titles available.

Although organic–inorganic hybrid materials have played indispensable roles as mechanical 1 – 4 , optical 5 , 6 , electronic 7 , 8 and biomedical materials 9 – 11 , isolated organic–inorganic hybrid molecules (at present limited to covalent compounds 12 , 13 ) are seldom used to prepare hybrid materials, owing to the distinct behaviours of organic covalent bonds 14 and inorganic ionic bonds 15 in molecular construction. Here we integrate typical covalent and ionic bonds within one molecule to create an organic–inorganic hybrid molecule, which can be used for bottom-up syntheses of hybrid materials. A combination of the organic covalent thioctic acid (TA) and the inorganic ionic calcium carbonate oligomer (CCO) through an acid–base reaction provides a TA–CCO hybrid molecule with the representative molecular formula TA 2 Ca(CaCO 3 ) 2 . Its dual reactivity involving copolymerization of the organic TA segment and inorganic CCO segment generates the respective covalent and ionic networks. The two networks are interconnected through TA–CCO complexes to form a covalent–ionic bicontinuous structure within the resulting hybrid material, poly(TA–CCO), which unifies paradoxical mechanical properties. The reversible binding of Ca 2+ –CO 3 2− bonds in the ionic network and S–S bonds in the covalent network ensures material reprocessability with plastic-like mouldability while preserving thermal stability. The coexistence of ceramic-like, rubber-like and plastic-like behaviours within poly(TA–CCO) goes beyond current classifications of materials to generate an ‘elastic ceramic plastic’. The bottom-up creation of organic–inorganic hybrid molecules provides a feasible pathway for the molecular engineering of hybrid materials, thereby supplementing the classical methodology used for the manufacture of organic–inorganic hybrid materials. Covalent organic molecules can be combined with ionic inorganic molecules to create a hybrid material demonstrating paradoxical mechanical properties in a bottom-up manner, enabling the manufacture of an ‘elastic ceramic plastic’.

Insufficient intracellular anabolism is a crucial factor involved in many pathological processes in the body 1 , 2 . The anabolism of intracellular substances requires the consumption of sufficient intracellular energy and the production of reducing equivalents. ATP acts as an ‘energy currency’ for biological processes in cells 3 , 4 , and the reduced form of NADPH is a key electron donor that provides reducing power for anabolism 5 . Under pathological conditions, it is difficult to correct impaired anabolism and to increase insufficient levels of ATP and NADPH to optimum concentrations 1 , 4 , 6 – 8 . Here we develop an independent and controllable nanosized plant-derived photosynthetic system based on nanothylakoid units (NTUs). To enable cross-species applications, we use a specific mature cell membrane (the chondrocyte membrane (CM)) for camouflage encapsulation. As proof of concept, we demonstrate that these CM-NTUs enter chondrocytes through membrane fusion, avoid lysosome degradation and achieve rapid penetration. Moreover, the CM-NTUs increase intracellular ATP and NADPH levels in situ following exposure to light and improve anabolism in degenerated chondrocytes. They can also systemically correct energy imbalance and restore cellular metabolism to improve cartilage homeostasis and protect against pathological progression of osteoarthritis. Our therapeutic strategy for degenerative diseases is based on a natural photosynthetic system that can controllably enhance cell anabolism by independently providing key energy and metabolic carriers. This study also provides an enhanced understanding of the preparation and application of bioorganisms and composite biomaterials for the treatment of disease. Proof of concept of the viability of a plant-derived photosynthetic system based on nanothylakoid units encapsulated in a chondrocyte membrane to enhance cell anabolism in chondrocytes is demonstrated.

Biomineralization is the intricate process by which living organisms orchestrate the formation of organic–inorganic composites by regulating the nucleation, orientation, growth, and assembly of inorganic minerals. As our comprehension of biomineralization principles deepens, novel strategies for fabricating inorganic materials based on these principles have emerged. Researchers can also harness biomineralization strategies to tackle challenges in both materials' science and biomedical fields, demonstrating a thriving research field. This review begins by introducing the concept of biomineralization and subsequently shifts its focus to a recently discovered chemical concept: inorganic ionic oligomers and their cross‐linking. As a novel approach for constructing inorganic materials, the inorganic ionic oligomer‐based strategy finds applications in biomimetic regeneration and repair of hard tissues, such as teeth and bones. Aside from innovative methods for material fabrication, biomineralization has emerged as an alternative method for tackling biomedical challenges by integrating materials with biological organisms, facilitating advancements in biomedical fields. Emerging material‐biological integrators play a critical role in areas like vaccine improvement, cancer therapy, universal blood transfusion, and arthritis treatment. This review highlights the profound impact of biomineralization in the development and design of high‐performance materials that go beyond traditional disciplinary boundaries, potentially promoting breakthroughs in materials science, chemical biology, biomedical, and numerous other domains. Biomineralization, a process in which organisms regulate the formation of inorganic minerals, has led to the proposal of many structural and functional biomimetic strategies by following the example of nature. This review describes the inorganic polymerization strategies and the construction of organism–material integrators inspired by biomineralization. The disciplinary leap of biomineralization from materials science to biology and even biomedicine is demonstrated.

Osteoclasts (OCs), the only cells capable of remodeling bone, can demineralize calcium minerals biologically. Naive OCs have limitations for the removal of ectopic calcification, such as in heterotopic ossification (HO), due to their restricted activity, migration and poor adhesion to sites of ectopic calcification. HO is the formation of pathological mature bone within extraskeletal soft tissues, and there are currently no reliable methods for removing these unexpected calcified plaques. In the present study, we develop a chemical approach to modify OCs with tetracycline (TC) to produce engineered OCs (TC-OCs) with an enhanced capacity for targeting and adhering to ectopic calcified tissue due to a broad affinity for calcium minerals. Unlike naive OCs, TC-OCs are able to effectively remove HO both in vitro and in vivo. This achievement indicates that HO can be reversed using modified OCs and holds promise for engineering cells as “living treatment agents” for cell therapy. Heterotopic ossification (HO) is the formation of pathological mature bone within extraskeletal soft tissues, and there are currently no reliable methods for removing these calcified plaques. Here, the authors demonstrate that chemically engineered osteoclasts coated with tetracycline can improve their targeting capacity to ectopic calcifications, which extends their bone resorption functions for the treatment of HO.

Bone marrow mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEVs) have been widely used for treating myocardial infarction (MI). However, low retention and short-lived therapeutic effects are still significant challenges. This study aimed to determine whether incorporation of MSC-derived sEVs in alginate hydrogel increases their retention in the heart thereby improving therapeutic effects. The optimal sodium alginate hydrogel incorporating sEVs system was determined by its release ability of sEVs and rheology of hydrogel. fluorescence imaging was utilized to evaluate the retention of sEVs in the heart. Immunoregulation and effects of sEVs on angiogenesis were analyzed by immunofluorescence staining. Echocardiography and Masson's trichrome staining were used to estimate cardiac function and infarct size. The delivery of sEVs incorporated in alginate hydrogel (sEVs-Gel) enhanced their retention in the heart. Compared with sEVs only treatment (sEVs), sEVs-Gel treatment significantly decreased cardiac cell apoptosis and promoted the polarization of macrophages at day 3 after MI. sEVs-Gel treatment also increased scar thickness and angiogenesis at four weeks post-infarction. Measurement of cardiac function and infarct size were significantly better in the sEVs-Gel group than in the group treated with sEVs only. Delivery of sEVs incorporated in alginate hydrogel provides a novel approach of cell-free therapy and optimizes the therapeutic effect of sEVs for MI.

In nature, a few living organisms such as diatoms, magnetotactic bacteria, and eggs have developed specific mineral structures, which can provide extensive protection or unique functions. However, most organisms do not have such structured materials due to their lack of biomineralization ability. The artificial introduction of biomimetic-constructed nanominerals is challenging but holds great promise. In this overview, we highlight two typical types of mineral- living complex systems. One involves biological surface-induced nanomaterials, which produces artificial living-mineral core-shell structures such as the mineral- encapsulated yeast, cyanobacteria, bacteria and viruses. The other involves internal nanominerals that could endow organisms with unique structures and properties. The applications of these biomimetic generated nanominerals are further discussed, mainly in four potential areas： storage, protection, ＂stealth＂ and delivery. Since biomineralization combines chemical, nano and biological technologies, we suggest that nanobiomimetic mineralization may open up another window for interdisciplinary research. Specifically, this is a novel material-based biological regulation strategy and the integration of living organisms with functional nanomaterials can create ＂super＂ or intelligent nanoscale living complexes for biotechnological practices.

Many biomineralization systems start from transient amorphous precursor phases, but the exact crystallization pathways and mechanisms remain largely unknown. The study of a well-defined biomimetic crystallization system is key for elucidating the possible mechanisms of biomineralization and monitoring the detailed crystallization pathways. In this review, we focus on amorphous phase mediated crystallization (APMC) pathways and their crystallization mechanisms in bio- and biomimetic-mineralization systems. The fundamental questions of biomineralization as well as the advantages and limitations of biomimetic model systems are discussed. This review could provide a full landscape of APMC systems for biomineralization and inspire new experiments aimed at some unresolved issues for understanding biomineralization.

Biomimetic mineralization can lead to advanced crystalline composites with common chemicals under ambient conditions. An exceptional example is biomimetic nacre with its superior fracture toughness. The synthesis of the prismatic layer with stiffness and wear resistance nonetheless remains an elusive goal. Herein, we apply a biomimetic mineralization method to grow prismatic-type CaCO 3 thin films, mimicking their biogenic counterparts found in mollusk shells with a three-step pathway: coating a polymer substrate, deposition of a granular transition layer, and mineralization of a prismatic overlayer. The synthetic prismatic overlayers exhibit structural similarity and comparable hardness and Young’s modulus to their biogenic counterparts. Furthermore, employment of a biomacromolecular soluble additive, silk fibroin, in fabrication of the prismatic thin films leads to micro-/nano-textures with enhanced toughness and emerging under-water superoleophobicity. This study highlights the crucial role of the granular transition layer in promoting competition growth of the prismatic layer. The exterior layers of mollusk shells are prismatic in nature, endowing them with stiffness and wear resistance. Inspired by these biominerals, here, Jiang and colleagues grow structurally similar prismatic-type CaCO 3 thin films with comparable stiffness and hardness.

In the pursuit of replicating the remarkable mechanical properties of natural biological composites like bone and seashell, developing artificial bulk materials that seamlessly integrate rigid inorganic components with ductile organic constituents has been a longstanding challenge. A key hurdle has been the establishment of robust and reliable linkages between these disparate building blocks. Mechanical metamaterials achieved by well-designed chemical structures, however, offer a promising solution to address this challenge. In this study, we demonstrate that the calcium phosphate-based inorganic-organic hybrid metamaterials trapping inorganic nanoparticles within long-chain polymeric networks and anchoring inorganic blocks to these networks via short-chain organic crosslinkers exhibit switchable and tunable high stiffness and elasticity. Additionally, these metamaterials not only exhibit peculiar mechanical characteristics, but also present excellent biocompatibility, as demonstrated by the in vivo tests using male rats and the in vitro tests. These results suggest a wide range of potential clinical applications. Developing artificial bulk materials that seamlessly integrate rigid inorganic components with ductile organic constituents is vital for replicating the mechanical properties of natural biological composites but elusive. Here, the authors report a calcium phosphate-based inorganic-organic hybrid metamaterial that seamlessly integrates the functional traits of inorganic and organic constituents.

Osteoporosis is an incurable chronic disease characterized by a lack of mineral mass in the bones. Here, the full recovery of osteoporotic bone is achieved by using a calcium phosphate polymer‐induced liquid‐precursor (CaP‐PILP). This free‐flowing CaP‐PILP material displays excellent bone inductivity and is able to readily penetrate into collagen fibrils and form intrafibrillar hydroxyapatite crystals oriented along the c‐axis. This ability is attributed to the microstructure of the material, which consists of homogeneously distributed ultrasmall (≈1 nm) amorphous calcium phosphate clusters. In vitro study shows the strong affinity of CaP‐PILP to osteoporotic bone, which can be uniformly distributed throughout the bone tissue to significantly increase the bone density. In vivo experiments show that the repaired bones exhibit satisfactory mechanical performance comparable with normal ones, following a promising treatment of osteoporosis by using CaP‐PILP. The discovery provides insight into the structure and property of biological nanocluster materials and their potential for hard tissue repair. The fluidity of calcium phosphate polymer‐induced liquid‐precursor (CaP‐PILP) allows the minimally‐invasive injection recovery of osteoporotic bone without the need for surgical incision in clinical applications. CaP‐PILP can recover osteoporotic bone back to normal, with a mechanical performance comparable to that of healthy bone. The unique characteristics of the material enable its application in osteoporotic bone recovery.