Yixuan Shang

Cardiac fibrosis acts as a serious worldwide health issue due to its prevalence in numerous forms of cardiac disease and its essential link to cardiac failure. Considering the efficiency of stem cell therapy for cardiac fibrosis, great efforts have been dedicated to developing accurate models for investigating their underlying therapeutic mechanisms. Herein we present an elaborate biomimetic cardiac fibrosis-on-a-chip based on Janus structural color film (SCF) to provide microphysiological visuals for stem cell therapeutic studies. By coculturing cardiomyocytes (CMs) and cardiac fibroblasts (FBs) on Janus SCF with fibrosis induction, the chip can recreate physiological intercellular crosstalk within the fibrotic microenvironment, elucidating the physiological alterations of fibrotic hearts. In particular, the Janus structural color film possesses superior perceptual capabilities for capturing and responding to a weak cardiac force, demonstrating synchronized structural color shifts. Based on these features, we have not only explored the dynamic relationship between color mapping and the evaluated disease phenotype but also demonstrated the self-reporting capacity of the cardiac fibrosis-on-a-chip for the assessment of mesenchymal stem cell-derived exosome therapy. These features suggest that such a chip can potentially facilitate the evolution of precision medicine strategies and create a protocol for preclinical cardiac drug screening.

Massive periosteal defects often significantly impair bone regeneration and repair, which have become a major clinical challenge. Unfortunately, current engineered periosteal materials can hardly currently focus on achieving high tissue adhesion property, being suitable for cell growth, and inducing cell orientation concurrently to meet the properties of nature periosteum. Additionally, the preparation of oriented surface nanotopography often relies on professional equipment. In this study, inspired by the oriented collagen structure of nature periosteum, we present a composite artificial periosteum with a layer of oriented nanotopography surface containing carbon nanotubes (CNTs), cross-linked with adhesive polydopamine (PDA) hydrogel on both terminals. An oriented surface structure that can simulate the oriented alignment of periosteal collagen fibers can be quickly and conveniently obtained via a simple stretching of the membrane in a water bath. With the help of CNTs, our artificial periosteum exhibits sufficient mechanical strength and desired oriented nanotopological structure surface, which further induces the directional arrangement of human bone marrow mesenchymal stem cells (hBMSCs) on the membrane. These oriented hBMSCs express significantly higher levels of osteogenic genes and proteins, while the resultant composite periosteum can be stably immobilized in vivo in the rat model of massive calvarial defect through the PDA hydrogel, which finally shows promising bone regeneration ability. We anticipate that the developed functional artificial periosteum has great potential in biomedical applications for the treatment of composite defects of the bone and periosteum.

Cardiac remodeling is critical for effective tissue recuperation, nevertheless, excessive formation and deposition of extracellular matrix components can result in the onset of cardiac fibrosis. Despite the emergence of novel therapies, there are still no lifelong therapeutic solutions for this issue. Understanding the detrimental cardiac remodeling may aid in the development of innovative treatment strategies to prevent or reverse fibrotic alterations in the heart. Further combining the latest understanding of disease pathogenesis with cardiac tissue engineering has provided the conversion of basic laboratory studies into the therapy of cardiac fibrosis patients as an increasingly viable prospect. This review presents the current main mechanisms and the potential tissue engineering of cardiac fibrosis. Approaches using biomedical materials‐based cardiac constructions are reviewed to consider key issues for simulating in vitro cardiac fibrosis, outlining a future perspective for preclinical applications.

Chronic hard-to-heal wounds draw great attention worldwide, as their treatments are limited by infections and hypoxia. Inspired by the natural oxygen production capacity of algae and the competitive advantage of beneficial bacteria over other microbes, we presented a living microecological hydrogel (LMH) with functionalized Chlorella and Bacillus subtilis encapsulation to realize continuous oxygen delivery and anti-infections for promoting chronic wound healing. As the hydrogel consisted of thermosensitive Pluronic F-127 and wet-adhesive polydopamine, the LMH could keep liquid at a low temperature while quickly solidifying and tightly adhering to the wound bed. It was demonstrated that by optimizing the proportion of the encapsulated microorganism, the Chlorella could continuously produce oxygen to relieve hypoxia and support the proliferation of B. subtilis , while B. subtilis could eliminate the colonized pathogenic bacteria. Thus, the LMH substantially promoted the healing of infected diabetic wounds. These features make the LMH valuable for practical clinical applications.

Water contamination resulting from heavy metal ions (HMIs) poses a severe threat to public health and the ecosystem. Attempts are tending to develop functional materials to realize efficient and intelligent adsorption of HMIs. Herein, self‐propelled structural color cylindrical micromotors (SCCMs) with reversible HMIs adsorption capacity and self‐reporting property are presented. The SCCMs are fabricated by using platinum nanoparticles (Pt NPs) tagged responsive hydrogel of carboxymethyl chitosan (CMC) and polyacrylamide (PAM) to asymmetrically replicate tubular colloidal crystal templates (TCCTs). Owing to the self‐propelled motion of the SCCMs, the enhancive ion–motor interactions bring significantly improved decontamination efficiency. Moreover, it is demonstrated that the SCCMs can realize quick and naked‐eye‐visible self‐reporting during the adsorption/desorption process based on their responsive structure color variation and superior adsorption capacity. Thus, it is anticipated that such intelligent SCCMs can significantly facilitate the evolution of sensing assays and diverse environmental fields.

Biohybrid actuators composed of living tissues and artificial materials have attracted increasing interest in recent years because of their extraordinary function of dynamically sensing and interacting with complex bioelectrical signals. Here, a novel biohybrid actuator with self-driven actuation and self-reported feedback is designed based on an anisotropic inverse opal substrate with periodical elliptical macropores and a hydrogel filling. The benefit of the anisotropic surface topography and high biocompatibility of the hydrogel is that the planted cardiomyocytes could be induced into a highly ordered alignment with recovering autonomic beating ability on the elastic substrate. Because of the cell elongation and contraction during cardiomyocyte beating, the anisotropic inverse opal substrates undergo a synchronous cycle of deformation actuations, which can be reported as corresponding shifts of their photonic band gaps and structural colors. These self-driven biohybrid actuators could be used as elements for the construction of unprecedented soft-bodied structural color robot, such as a biomimetic guppy with a swinging tail. Besides, with the integration of a self-driven biohybrid actuator and microfluidics, the advanced heart-on-a-chip with the feature of microphysiological visuality has been developed for integrated cell monitoring and drug testing. This anisotropic inverse opal-derived biohybrid actuator could be widely applied in biomedical.