Self-assembled hierarchically structured organic-inorganic composite systems

Progress in the application of sustained-release drug microspheres in tissue engineering

Sustained-release drug-loaded microspheres provide a long-acting sustained release, with targeted and other effects. There are many types of sustained-release drug microspheres and various preparation methods, and they are easy to operate. For these reasons, they have attracted widespread interest and are widely used in tissue engineering and other fields. In this paper, we provide a systematic review of the application of sustained-release drug microspheres in tissue engineering. First, we introduce this new type of drug delivery system (sustained-release drug carriers), describe the types of sustained-release drug microspheres, and summarize the characteristics of different microspheres. Second, we summarize the preparation methods of sustained-release drug microspheres and summarize the materials required for preparing microspheres. Third, various applications of sustained-release drug microspheres in tissue engineering are summarized. Finally, we summarize the shortcomings and discuss future prospects in the development of sustained-release drug microspheres. The purpose of this paper was to provide a further systematic understanding of the application of sustained-release drug microspheres in tissue engineering for the personnel engaged in related fields and to provide inspiration and new ideas for studies in related fields.

Oriented attachment and aggregation as a viable pathway to self-assembled organic/inorganic hybrid materials

The intrinsic particle-based mechanisms of calcium sulfate crystallisation are exploited to incorporate specific organic polymers in the emerging mineral phase and thus obtain biomimetic organic/inorganic hybrid structures via self-organisation.

Numerical investigation on the enhanced damping behavior of bio-inspired nacreous composites by introducing interlocked structure

Due to the unique "Brick-and-Mortar" structure, nacre exhibits extraordinary mechanical properties such as high strength and toughness, which are naturally exclusive in traditional engineering materials. The main threat to the shell is the impact load along the direction perpendicular to the lamellar structure. However, how it attenuates stress wave and dissipates kinetic energy during impact events remains unclear, especially along different loading directions (the directions perpendicular and parallel to the lamellar structure). In this paper, damping performance of nacreous bio-inspired composites is investigated to evaluate the energy dissipation from the perspective of dynamic modulus using theoretical and numerical methods. It is found that the stress states and Poisson's ratio of the "mortar" exert remarkable influence on composites' loss modulus. Moreover, the predicted optimal aspect ratio in this work is consistent with the previously reported experimental observation. Additionally, by introducing interlocked structure, the composites show strong direction-dependent damping behaviors, and the enhanced loss modulus is observed both in longitudinal and normal direction. The findings are not only expected to achieve a deep understanding of the dynamic energy dissipation mechanism of nacre, but also to provide a guideline for design of bio-inspired composites responding to shock loads.

Mineral self-organization on a lifeless planet

It has been experimentally demonstrated that, under alkaline conditions, silica is able to induce the formation of mineral self-assembled inorganic-inorganic composite materials similar in morphology, texture and nanostructure to the hybrid biomineral structures that, millions of years later, life was able to self-organize. These mineral self-organized structures (MISOS) have been also shown to work as effective catalysts for prebiotic chemical reactions and to easily create compartmentalization within the solutions where they form. We reason that, during the very earliest history of this planet, there was a geochemical scenario that inevitably led to the existence of a large-scale factory of simple and complex organic compounds, many of which were relevant to prebiotic chemistry. The factory was built on a silica-rich high-pH ocean and powered by two main factors: a) a quasi-infinite source of simple carbon molecules synthesized abiotically from reactions associated with serpentinization, or transported from meteorites and produced from their impact on that alkaline ocean, and b) the formation of self-organized silica-metal mineral composites that catalyze the condensation of simple molecules in a methane-rich reduced atmosphere. We discuss the plausibility of this geochemical scenario, review the details of the formation of MISOS and its catalytic properties and the transition towards a slightly alkaline to neutral ocean.

Liquid-crystalline nanoarchitectures for tissue engineering

Hierarchical orders are found throughout all levels of biosystems, from simple biopolymers, subcellular organelles, single cells, and macroscopic tissues to bulky organs. Especially, biological tissues and cells have long been known to exhibit liquid crystal (LC) orders or their structural analogues. Inspired by those native architectures, there has recently been increased interest in research for engineering nanobiomaterials by incorporating LC templates and scaffolds. In this review, we introduce and correlate diverse LC nanoarchitectures with their biological functionalities, in the context of tissue engineering applications. In particular, the tissue-mimicking LC materials with different LC phases and the regenerative potential of hard and soft tissues are summarized. In addition, the multifaceted aspects of LC architectures for developing tissue-engineered products are envisaged. Lastly, a perspective on the opportunities and challenges for applying LC nanoarchitectures in tissue engineering fields is discussed.